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@@ -1,3514 +0,0 @@
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-/* READ THIS COMMENT BEFORE HACKING THIS FILE.
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- *
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- * This eventdns.c copy has diverged a bit from Libevent's version, and it's
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- * no longer easy to resynchronize them. Once Tor requires Libevent 2.0, we
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- * will just dump this file and use Libevent's evdns code.
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- *
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- * Therefore, you probably shouldn't make any change here without making it to
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- * Libevent as well: it's not good for the implementation to diverge even
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- * more. Also, we can't shouldn't wantonly the API here (since Libevent APIs
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- * can't change in ways that break user behavior). Also, we shouldn't bother
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- * with cosmetic changes: the whole module is slated for demolition, so
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- * there's no point dusting the linebreaks or re-painting the parser.
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- *
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- * (We can't just drop the Libevent 2.0 evdns implementation in here instead,
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- * since it depends pretty heavily on parts of Libevent 2.0.)
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- */
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-
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-/* Async DNS Library
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- * Adam Langley <agl@imperialviolet.org>
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- * Public Domain code
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- *
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- * This software is Public Domain. To view a copy of the public domain dedication,
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- * visit http://creativecommons.org/licenses/publicdomain/ or send a letter to
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- * Creative Commons, 559 Nathan Abbott Way, Stanford, California 94305, USA.
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- *
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- * I ask and expect, but do not require, that all derivative works contain an
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- * attribution similar to:
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- * Parts developed by Adam Langley <agl@imperialviolet.org>
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- *
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- * You may wish to replace the word "Parts" with something else depending on
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- * the amount of original code.
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- *
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- * (Derivative works does not include programs which link against, run or include
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- * the source verbatim in their source distributions)
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- *
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- * Version: 0.1b
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- */
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-
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-#include "eventdns_tor.h"
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-#include "util.h"
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-#include <sys/types.h>
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-/* #define NDEBUG */
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-
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-#ifndef DNS_USE_CPU_CLOCK_FOR_ID
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-#ifndef DNS_USE_GETTIMEOFDAY_FOR_ID
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-#ifndef DNS_USE_OPENSSL_FOR_ID
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-#error Must configure at least one id generation method.
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-#error Please see the documentation.
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-#endif
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-#endif
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-#endif
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-
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-#ifdef DNS_USE_CPU_CLOCK_FOR_ID
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-#ifdef DNS_USE_OPENSSL_FOR_ID
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-#error Multiple id options selected
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-#endif
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-#ifdef DNS_USE_GETTIMEOFDAY_FOR_ID
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-#error Multiple id options selected
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-#endif
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-#include <time.h>
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-#endif
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-
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-#ifdef DNS_USE_OPENSSL_FOR_ID
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-#ifdef DNS_USE_GETTIMEOFDAY_FOR_ID
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-#error Multiple id options selected
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-#endif
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-#include <openssl/rand.h>
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-#endif
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-
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-#include <string.h>
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-#ifdef HAVE_FCNTL_H
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-#include <fcntl.h>
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-#endif
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-#ifdef HAVE_SYS_TIME_H
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-#include <sys/time.h>
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-#endif
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-#ifdef HAVE_STDINT_H
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-#include <stdint.h>
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-#endif
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-#include <stdlib.h>
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-#include <errno.h>
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-#include <assert.h>
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-#ifdef HAVE_UNISTD_H
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-#include <unistd.h>
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-#endif
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-#ifdef HAVE_LIMITS_H
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-#include <limits.h>
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-#endif
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-#include <sys/stat.h>
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-#include <ctype.h>
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-#include <stdio.h>
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-#include <stdarg.h>
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-
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-#include "eventdns.h"
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-
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-#ifdef _WIN32
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-#include <windows.h>
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-#include <winsock2.h>
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-#include <iphlpapi.h>
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-#else
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-#include <sys/socket.h>
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-#include <netinet/in.h>
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-#include <arpa/inet.h>
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-#endif
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-
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-#ifdef HAVE_NETINET_IN6_H
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-#include <netinet/in6.h>
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-#endif
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-
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-#ifdef _WIN32
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-typedef int socklen_t;
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-#endif
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-
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-#define EVDNS_LOG_DEBUG 0
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-#define EVDNS_LOG_WARN 1
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-
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-#ifndef HOST_NAME_MAX
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-#define HOST_NAME_MAX 255
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-#endif
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-
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-#ifndef NDEBUG
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-#include <stdio.h>
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-#endif
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-
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-/* for debugging possible memory leaks. */
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-#define mm_malloc(x) tor_malloc(x)
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-#define mm_realloc(x,y) tor_realloc((x),(y))
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-#define mm_free(x) tor_free(x)
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-#define mm_strdup(x) tor_strdup(x)
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-#define _mm_free(x) tor_free_(x)
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-
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-#undef MIN
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-#define MIN(a,b) ((a)<(b)?(a):(b))
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-
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-#if 0
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-#ifdef __USE_ISOC99B
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-/* libevent doesn't work without this */
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-typedef uint8_t u_char;
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-typedef unsigned int uint;
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-#endif
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-#endif
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-#include <event.h>
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-
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-#define u64 uint64_t
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-#define u32 uint32_t
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-#define u16 uint16_t
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-#define u8 uint8_t
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-
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-#define MAX_ADDRS 4 /* maximum number of addresses from a single packet */
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-/* which we bother recording */
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-
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-#define TYPE_A EVDNS_TYPE_A
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-#define TYPE_CNAME 5
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-#define TYPE_PTR EVDNS_TYPE_PTR
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-#define TYPE_AAAA EVDNS_TYPE_AAAA
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-
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-#define CLASS_INET EVDNS_CLASS_INET
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-
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-#define CLEAR(x) do { memset((x), 0xF0, sizeof(*(x))); } while(0)
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-
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-struct evdns_request {
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- u8 *request; /* the dns packet data */
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- unsigned int request_len;
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- int reissue_count;
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- int tx_count; /* the number of times that this packet has been sent */
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- unsigned int request_type; /* TYPE_PTR or TYPE_A */
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- void *user_pointer; /* the pointer given to us for this request */
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- evdns_callback_type user_callback;
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- struct nameserver *ns; /* the server which we last sent it */
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-
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- /* elements used by the searching code */
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- int search_index;
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- struct search_state *search_state;
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- char *search_origname; /* needs to be mm_free()ed */
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- int search_flags;
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-
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- /* these objects are kept in a circular list */
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- struct evdns_request *next, *prev;
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-
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- struct event timeout_event;
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-
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- u16 trans_id; /* the transaction id */
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- char request_appended; /* true if the request pointer is data which follows this struct */
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- char transmit_me; /* needs to be transmitted */
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-};
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-
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-#ifndef HAVE_STRUCT_IN6_ADDR
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-struct in6_addr {
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- u8 s6_addr[16];
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-};
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-#endif
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-
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-struct reply {
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- unsigned int type;
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- unsigned int have_answer;
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- union {
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- struct {
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- u32 addrcount;
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- u32 addresses[MAX_ADDRS];
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- } a;
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- struct {
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- u32 addrcount;
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- struct in6_addr addresses[MAX_ADDRS];
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- } aaaa;
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- struct {
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- char name[HOST_NAME_MAX];
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- } ptr;
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- } data;
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-};
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-
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-struct nameserver {
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- int socket; /* a connected UDP socket */
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- struct sockaddr_storage address;
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- int failed_times; /* number of times which we have given this server a chance */
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- int timedout; /* number of times in a row a request has timed out */
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- struct event event;
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- /* these objects are kept in a circular list */
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- struct nameserver *next, *prev;
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- struct event timeout_event; /* used to keep the timeout for */
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- /* when we next probe this server. */
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- /* Valid if state == 0 */
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- char state; /* zero if we think that this server is down */
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- char choked; /* true if we have an EAGAIN from this server's socket */
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- char write_waiting; /* true if we are waiting for EV_WRITE events */
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-};
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-
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-static struct evdns_request *req_head = NULL, *req_waiting_head = NULL;
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-static struct nameserver *server_head = NULL;
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-
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-/* Represents a local port where we're listening for DNS requests. Right now, */
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-/* only UDP is supported. */
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-struct evdns_server_port {
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- int socket; /* socket we use to read queries and write replies. */
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- int refcnt; /* reference count. */
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- char choked; /* Are we currently blocked from writing? */
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- char closing; /* Are we trying to close this port, pending writes? */
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- evdns_request_callback_fn_type user_callback; /* Fn to handle requests */
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- void *user_data; /* Opaque pointer passed to user_callback */
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- struct event event; /* Read/write event */
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- /* circular list of replies that we want to write. */
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- struct server_request *pending_replies;
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-};
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-
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-/* Represents part of a reply being built. (That is, a single RR.) */
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-struct server_reply_item {
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- struct server_reply_item *next; /* next item in sequence. */
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- char *name; /* name part of the RR */
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- u16 type : 16; /* The RR type */
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- u16 class : 16; /* The RR class (usually CLASS_INET) */
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- u32 ttl; /* The RR TTL */
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- char is_name; /* True iff data is a label */
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- u16 datalen; /* Length of data; -1 if data is a label */
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- void *data; /* The contents of the RR */
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-};
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-
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-/* Represents a request that we've received as a DNS server, and holds */
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-/* the components of the reply as we're constructing it. */
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-struct server_request {
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- /* Pointers to the next and previous entries on the list of replies */
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- /* that we're waiting to write. Only set if we have tried to respond */
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- /* and gotten EAGAIN. */
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- struct server_request *next_pending;
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- struct server_request *prev_pending;
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-
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- u16 trans_id; /* Transaction id. */
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- struct evdns_server_port *port; /* Which port received this request on? */
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- struct sockaddr_storage addr; /* Where to send the response */
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- socklen_t addrlen; /* length of addr */
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-
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- int n_answer; /* how many answer RRs have been set? */
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- int n_authority; /* how many authority RRs have been set? */
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- int n_additional; /* how many additional RRs have been set? */
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-
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- struct server_reply_item *answer; /* linked list of answer RRs */
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- struct server_reply_item *authority; /* linked list of authority RRs */
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- struct server_reply_item *additional; /* linked list of additional RRs */
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-
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- /* Constructed response. Only set once we're ready to send a reply. */
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- /* Once this is set, the RR fields are cleared, and no more should be set. */
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- char *response;
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- size_t response_len;
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-
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- /* Caller-visible fields: flags, questions. */
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- struct evdns_server_request base;
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-};
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-
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-/* helper macro */
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-#define OFFSET_OF(st, member) ((off_t) (((char*)&((st*)0)->member)-(char*)0))
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-
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-/* Given a pointer to an evdns_server_request, get the corresponding */
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-/* server_request. */
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-#define TO_SERVER_REQUEST(base_ptr) \
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- ((struct server_request*) \
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- (((char*)(base_ptr) - OFFSET_OF(struct server_request, base))))
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-
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-/* The number of good nameservers that we have */
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-static int global_good_nameservers = 0;
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-
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-/* inflight requests are contained in the req_head list */
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-/* and are actually going out across the network */
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-static int global_requests_inflight = 0;
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-/* requests which aren't inflight are in the waiting list */
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-/* and are counted here */
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-static int global_requests_waiting = 0;
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-
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-static int global_max_requests_inflight = 64;
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-
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-static struct timeval global_timeout = {5, 0}; /* 5 seconds */
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-static int global_max_reissues = 1; /* a reissue occurs when we get some errors from the server */
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-static int global_max_retransmits = 3; /* number of times we'll retransmit a request which timed out */
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-/* number of timeouts in a row before we consider this server to be down */
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-static int global_max_nameserver_timeout = 3;
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-
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-/* true iff we should use the 0x20 hack. */
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-static int global_randomize_case = 1;
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-
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-/* These are the timeout values for nameservers. If we find a nameserver is down */
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-/* we try to probe it at intervals as given below. Values are in seconds. */
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-static const struct timeval global_nameserver_timeouts[] = {{10, 0}, {60, 0}, {300, 0}, {900, 0}, {3600, 0}};
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-static const int global_nameserver_timeouts_length = (int)(sizeof(global_nameserver_timeouts)/sizeof(struct timeval));
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-
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-static struct nameserver *nameserver_pick(void);
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-static void evdns_request_insert(struct evdns_request *req, struct evdns_request **head);
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-static void nameserver_ready_callback(int fd, short events, void *arg);
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-static int evdns_transmit(void);
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-static int evdns_request_transmit(struct evdns_request *req);
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-static void nameserver_send_probe(struct nameserver *const ns);
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-static void search_request_finished(struct evdns_request *const);
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-static int search_try_next(struct evdns_request *const req);
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-static int search_request_new(int type, const char *const name, int flags, evdns_callback_type user_callback, void *user_arg);
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-static void evdns_requests_pump_waiting_queue(void);
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-static u16 transaction_id_pick(void);
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-static struct evdns_request *request_new(int type, const char *name, int flags, evdns_callback_type callback, void *ptr);
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-static void request_submit(struct evdns_request *req);
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-
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-static int server_request_free(struct server_request *req);
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-static void server_request_free_answers(struct server_request *req);
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-static void server_port_free(struct evdns_server_port *port);
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-static void server_port_ready_callback(int fd, short events, void *arg);
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-
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-static int strtoint(const char *const str);
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-
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-#ifdef _WIN32
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-static int
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-last_error(int sock)
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-{
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- int optval, optvallen=sizeof(optval);
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- int err = WSAGetLastError();
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- if (err == WSAEWOULDBLOCK && sock >= 0) {
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- if (getsockopt(sock, SOL_SOCKET, SO_ERROR, (void*)&optval,
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- &optvallen))
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- return err;
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- if (optval)
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- return optval;
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- }
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- return err;
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-
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-}
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-static int
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-error_is_eagain(int err)
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-{
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- return err == EAGAIN || err == WSAEWOULDBLOCK;
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-}
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-#define inet_aton(c, addr) tor_inet_aton((c), (addr))
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-#define CLOSE_SOCKET(x) closesocket(x)
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-#else
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-#define last_error(sock) (errno)
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-#if EAGAIN != EWOULDBLOCK
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-#define error_is_eagain(err) ((err) == EAGAIN || (err) == EWOULDBLOCK)
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-#else
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-#define error_is_eagain(err) ((err) == EAGAIN)
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-#endif
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-#define CLOSE_SOCKET(x) close(x)
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-#endif
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-
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-#define ISSPACE(c) TOR_ISSPACE(c)
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-#define ISDIGIT(c) TOR_ISDIGIT(c)
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-#define ISALPHA(c) TOR_ISALPHA(c)
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-#define TOLOWER(c) TOR_TOLOWER(c)
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-#define TOUPPER(c) TOR_TOUPPER(c)
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-
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-#ifndef NDEBUG
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-static const char *
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-debug_ntoa(u32 address)
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-{
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- static char buf[32];
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- u32 a = ntohl(address);
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|
|
- tor_snprintf(buf, sizeof(buf), "%d.%d.%d.%d",
|
|
|
- (int)(u8)((a>>24)&0xff),
|
|
|
- (int)(u8)((a>>16)&0xff),
|
|
|
- (int)(u8)((a>>8 )&0xff),
|
|
|
- (int)(u8)((a )&0xff));
|
|
|
- return buf;
|
|
|
-}
|
|
|
-static const char *
|
|
|
-debug_ntop(const struct sockaddr *sa)
|
|
|
-{
|
|
|
- if (sa->sa_family == AF_INET) {
|
|
|
- struct sockaddr_in *sin = (struct sockaddr_in *) sa;
|
|
|
- return debug_ntoa(sin->sin_addr.s_addr);
|
|
|
- }
|
|
|
- if (sa->sa_family == AF_INET6) {
|
|
|
- /* Tor-specific. In libevent, add more check code. */
|
|
|
- static char buf[128];
|
|
|
- struct sockaddr_in6 *sin = (struct sockaddr_in6 *) sa;
|
|
|
- tor_inet_ntop(AF_INET6, &sin->sin6_addr, buf, sizeof(buf));
|
|
|
- return buf;
|
|
|
- }
|
|
|
- return "<unknown>";
|
|
|
-}
|
|
|
-#endif
|
|
|
-
|
|
|
-static evdns_debug_log_fn_type evdns_log_fn = NULL;
|
|
|
-
|
|
|
-void
|
|
|
-evdns_set_log_fn(evdns_debug_log_fn_type fn)
|
|
|
-{
|
|
|
- evdns_log_fn = fn;
|
|
|
-}
|
|
|
-
|
|
|
-#ifdef __GNUC__
|
|
|
-#define EVDNS_LOG_CHECK __attribute__ ((format(printf, 2, 3)))
|
|
|
-#else
|
|
|
-#define EVDNS_LOG_CHECK
|
|
|
-#endif
|
|
|
-
|
|
|
-static void evdns_log(int warn, const char *fmt, ...) EVDNS_LOG_CHECK;
|
|
|
-static void
|
|
|
-evdns_log(int warn, const char *fmt, ...)
|
|
|
-{
|
|
|
- va_list args;
|
|
|
- static char buf[512];
|
|
|
- if (!evdns_log_fn)
|
|
|
- return;
|
|
|
- va_start(args,fmt);
|
|
|
- tor_vsnprintf(buf, sizeof(buf), fmt, args);
|
|
|
- evdns_log_fn(warn, buf);
|
|
|
- va_end(args);
|
|
|
-}
|
|
|
-
|
|
|
-static int
|
|
|
-sockaddr_eq(const struct sockaddr *sa1, const struct sockaddr *sa2,
|
|
|
- int include_port)
|
|
|
-{
|
|
|
- if (sa1->sa_family != sa2->sa_family)
|
|
|
- return 0;
|
|
|
- if (sa1->sa_family == AF_INET) {
|
|
|
- const struct sockaddr_in *sin1, *sin2;
|
|
|
- sin1 = (const struct sockaddr_in *)sa1;
|
|
|
- sin2 = (const struct sockaddr_in *)sa2;
|
|
|
- if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
|
|
|
- return 0;
|
|
|
- else if (include_port && sin1->sin_port != sin2->sin_port)
|
|
|
- return 0;
|
|
|
- else
|
|
|
- return 1;
|
|
|
- }
|
|
|
-#ifdef AF_INET6
|
|
|
- if (sa1->sa_family == AF_INET6) {
|
|
|
- const struct sockaddr_in6 *sin1, *sin2;
|
|
|
- sin1 = (const struct sockaddr_in6 *)sa1;
|
|
|
- sin2 = (const struct sockaddr_in6 *)sa2;
|
|
|
- if (tor_memneq(sin1->sin6_addr.s6_addr, sin2->sin6_addr.s6_addr, 16))
|
|
|
- return 0;
|
|
|
- else if (include_port && sin1->sin6_port != sin2->sin6_port)
|
|
|
- return 0;
|
|
|
- else
|
|
|
- return 1;
|
|
|
- }
|
|
|
-#endif
|
|
|
- return 1;
|
|
|
-}
|
|
|
-
|
|
|
-#define add_timeout_event(s, to) \
|
|
|
- (event_add(&(s)->timeout_event, (to)))
|
|
|
-#define del_timeout_event(s) \
|
|
|
- (event_del(&(s)->timeout_event))
|
|
|
-
|
|
|
-/* This walks the list of inflight requests to find the */
|
|
|
-/* one with a matching transaction id. Returns NULL on */
|
|
|
-/* failure */
|
|
|
-static struct evdns_request *
|
|
|
-request_find_from_trans_id(u16 trans_id) {
|
|
|
- struct evdns_request *req = req_head, *const started_at = req_head;
|
|
|
-
|
|
|
- if (req) {
|
|
|
- do {
|
|
|
- if (req->trans_id == trans_id) return req;
|
|
|
- req = req->next;
|
|
|
- } while (req != started_at);
|
|
|
- }
|
|
|
-
|
|
|
- return NULL;
|
|
|
-}
|
|
|
-
|
|
|
-/* a libevent callback function which is called when a nameserver */
|
|
|
-/* has gone down and we want to test if it has came back to life yet */
|
|
|
-static void
|
|
|
-nameserver_prod_callback(int fd, short events, void *arg) {
|
|
|
- struct nameserver *const ns = (struct nameserver *) arg;
|
|
|
- (void)fd;
|
|
|
- (void)events;
|
|
|
-
|
|
|
- nameserver_send_probe(ns);
|
|
|
-}
|
|
|
-
|
|
|
-/* a libevent callback which is called when a nameserver probe (to see if */
|
|
|
-/* it has come back to life) times out. We increment the count of failed_times */
|
|
|
-/* and wait longer to send the next probe packet. */
|
|
|
-static void
|
|
|
-nameserver_probe_failed(struct nameserver *const ns) {
|
|
|
- const struct timeval * timeout;
|
|
|
- del_timeout_event(ns);
|
|
|
-
|
|
|
- if (ns->state == 1) {
|
|
|
- /* This can happen if the nameserver acts in a way which makes us mark */
|
|
|
- /* it as bad and then starts sending good replies. */
|
|
|
- return;
|
|
|
- }
|
|
|
-
|
|
|
- timeout =
|
|
|
- &global_nameserver_timeouts[MIN(ns->failed_times,
|
|
|
- global_nameserver_timeouts_length - 1)];
|
|
|
- ns->failed_times++;
|
|
|
-
|
|
|
- if (add_timeout_event(ns, (struct timeval *) timeout) < 0) {
|
|
|
- evdns_log(EVDNS_LOG_WARN,
|
|
|
- "Error from libevent when adding timer event for %s",
|
|
|
- debug_ntop((struct sockaddr *)&ns->address));
|
|
|
- /* ???? Do more? */
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* called when a nameserver has been deemed to have failed. For example, too */
|
|
|
-/* many packets have timed out etc */
|
|
|
-static void
|
|
|
-nameserver_failed(struct nameserver *const ns, const char *msg) {
|
|
|
- struct evdns_request *req, *started_at;
|
|
|
- /* if this nameserver has already been marked as failed */
|
|
|
- /* then don't do anything */
|
|
|
- if (!ns->state) return;
|
|
|
-
|
|
|
- evdns_log(EVDNS_LOG_WARN, "Nameserver %s has failed: %s",
|
|
|
- debug_ntop((struct sockaddr *)&ns->address), msg);
|
|
|
- global_good_nameservers--;
|
|
|
- assert(global_good_nameservers >= 0);
|
|
|
- if (global_good_nameservers == 0) {
|
|
|
- evdns_log(EVDNS_LOG_WARN, "All nameservers have failed");
|
|
|
- }
|
|
|
-
|
|
|
- ns->state = 0;
|
|
|
- ns->failed_times = 1;
|
|
|
-
|
|
|
- if (add_timeout_event(ns, (struct timeval *) &global_nameserver_timeouts[0]) < 0) {
|
|
|
- evdns_log(EVDNS_LOG_WARN,
|
|
|
- "Error from libevent when adding timer event for %s",
|
|
|
- debug_ntop((struct sockaddr *)&ns->address));
|
|
|
- /* ???? Do more? */
|
|
|
- }
|
|
|
-
|
|
|
- /* walk the list of inflight requests to see if any can be reassigned to */
|
|
|
- /* a different server. Requests in the waiting queue don't have a */
|
|
|
- /* nameserver assigned yet */
|
|
|
-
|
|
|
- /* if we don't have *any* good nameservers then there's no point */
|
|
|
- /* trying to reassign requests to one */
|
|
|
- if (!global_good_nameservers) return;
|
|
|
-
|
|
|
- req = req_head;
|
|
|
- started_at = req_head;
|
|
|
- if (req) {
|
|
|
- do {
|
|
|
- if (req->tx_count == 0 && req->ns == ns) {
|
|
|
- /* still waiting to go out, can be moved */
|
|
|
- /* to another server */
|
|
|
- req->ns = nameserver_pick();
|
|
|
- }
|
|
|
- req = req->next;
|
|
|
- } while (req != started_at);
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-static void
|
|
|
-nameserver_up(struct nameserver *const ns) {
|
|
|
- if (ns->state) return;
|
|
|
- evdns_log(EVDNS_LOG_WARN, "Nameserver %s is back up",
|
|
|
- debug_ntop((struct sockaddr *)&ns->address));
|
|
|
- del_timeout_event(ns);
|
|
|
- ns->state = 1;
|
|
|
- ns->failed_times = 0;
|
|
|
- ns->timedout = 0;
|
|
|
- global_good_nameservers++;
|
|
|
-}
|
|
|
-
|
|
|
-static void
|
|
|
-request_trans_id_set(struct evdns_request *const req, const u16 trans_id) {
|
|
|
- req->trans_id = trans_id;
|
|
|
- *((u16 *) req->request) = htons(trans_id);
|
|
|
-}
|
|
|
-
|
|
|
-/* Called to remove a request from a list and dealloc it. */
|
|
|
-/* head is a pointer to the head of the list it should be */
|
|
|
-/* removed from or NULL if the request isn't in a list. */
|
|
|
-static void
|
|
|
-request_finished(struct evdns_request *const req, struct evdns_request **head) {
|
|
|
- if (head) {
|
|
|
- if (req->next == req) {
|
|
|
- /* only item in the list */
|
|
|
- *head = NULL;
|
|
|
- } else {
|
|
|
- req->next->prev = req->prev;
|
|
|
- req->prev->next = req->next;
|
|
|
- if (*head == req) *head = req->next;
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Removing timeout for request %lx",
|
|
|
- (unsigned long) req);
|
|
|
- del_timeout_event(req);
|
|
|
-
|
|
|
- search_request_finished(req);
|
|
|
- global_requests_inflight--;
|
|
|
-
|
|
|
- if (!req->request_appended) {
|
|
|
- /* need to free the request data on it's own */
|
|
|
- mm_free(req->request);
|
|
|
- } else {
|
|
|
- /* the request data is appended onto the header */
|
|
|
- /* so everything gets mm_free()ed when we: */
|
|
|
- }
|
|
|
-
|
|
|
- CLEAR(req);
|
|
|
- _mm_free(req);
|
|
|
-
|
|
|
- evdns_requests_pump_waiting_queue();
|
|
|
-}
|
|
|
-
|
|
|
-/* This is called when a server returns a funny error code. */
|
|
|
-/* We try the request again with another server. */
|
|
|
-/* */
|
|
|
-/* return: */
|
|
|
-/* 0 ok */
|
|
|
-/* 1 failed/reissue is pointless */
|
|
|
-static int
|
|
|
-request_reissue(struct evdns_request *req) {
|
|
|
- const struct nameserver *const last_ns = req->ns;
|
|
|
- /* the last nameserver should have been marked as failing */
|
|
|
- /* by the caller of this function, therefore pick will try */
|
|
|
- /* not to return it */
|
|
|
- req->ns = nameserver_pick();
|
|
|
- if (req->ns == last_ns) {
|
|
|
- /* ... but pick did return it */
|
|
|
- /* not a lot of point in trying again with the */
|
|
|
- /* same server */
|
|
|
- return 1;
|
|
|
- }
|
|
|
-
|
|
|
- req->reissue_count++;
|
|
|
- req->tx_count = 0;
|
|
|
- req->transmit_me = 1;
|
|
|
-
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-/* this function looks for space on the inflight queue and promotes */
|
|
|
-/* requests from the waiting queue if it can. */
|
|
|
-static void
|
|
|
-evdns_requests_pump_waiting_queue(void) {
|
|
|
- while (global_requests_inflight < global_max_requests_inflight &&
|
|
|
- global_requests_waiting) {
|
|
|
- struct evdns_request *req;
|
|
|
- /* move a request from the waiting queue to the inflight queue */
|
|
|
- assert(req_waiting_head);
|
|
|
- if (req_waiting_head->next == req_waiting_head) {
|
|
|
- /* only one item in the queue */
|
|
|
- req = req_waiting_head;
|
|
|
- req_waiting_head = NULL;
|
|
|
- } else {
|
|
|
- req = req_waiting_head;
|
|
|
- req->next->prev = req->prev;
|
|
|
- req->prev->next = req->next;
|
|
|
- req_waiting_head = req->next;
|
|
|
- }
|
|
|
-
|
|
|
- global_requests_waiting--;
|
|
|
- global_requests_inflight++;
|
|
|
-
|
|
|
- req->ns = nameserver_pick();
|
|
|
- request_trans_id_set(req, transaction_id_pick());
|
|
|
-
|
|
|
- evdns_request_insert(req, &req_head);
|
|
|
- evdns_request_transmit(req);
|
|
|
- evdns_transmit();
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-static void
|
|
|
-reply_callback(struct evdns_request *const req, u32 ttl, u32 err, struct reply *reply) {
|
|
|
- switch (req->request_type) {
|
|
|
- case TYPE_A:
|
|
|
- if (reply)
|
|
|
- req->user_callback(DNS_ERR_NONE, DNS_IPv4_A,
|
|
|
- reply->data.a.addrcount, ttl,
|
|
|
- reply->data.a.addresses,
|
|
|
- req->user_pointer);
|
|
|
- else
|
|
|
- req->user_callback(err, 0, 0, 0, NULL, req->user_pointer);
|
|
|
- return;
|
|
|
- case TYPE_PTR:
|
|
|
- if (reply) {
|
|
|
- char *name = reply->data.ptr.name;
|
|
|
- req->user_callback(DNS_ERR_NONE, DNS_PTR, 1, ttl,
|
|
|
- &name, req->user_pointer);
|
|
|
- } else {
|
|
|
- req->user_callback(err, 0, 0, 0, NULL,
|
|
|
- req->user_pointer);
|
|
|
- }
|
|
|
- return;
|
|
|
- case TYPE_AAAA:
|
|
|
- if (reply)
|
|
|
- req->user_callback(DNS_ERR_NONE, DNS_IPv6_AAAA,
|
|
|
- reply->data.aaaa.addrcount, ttl,
|
|
|
- reply->data.aaaa.addresses,
|
|
|
- req->user_pointer);
|
|
|
- else
|
|
|
- req->user_callback(err, 0, 0, 0, NULL, req->user_pointer);
|
|
|
- return;
|
|
|
- }
|
|
|
- assert(0);
|
|
|
-}
|
|
|
-
|
|
|
-/* this processes a parsed reply packet */
|
|
|
-static void
|
|
|
-reply_handle(struct evdns_request *const req, u16 flags, u32 ttl, struct reply *reply) {
|
|
|
- int error;
|
|
|
- static const int error_codes[] = {DNS_ERR_FORMAT, DNS_ERR_SERVERFAILED, DNS_ERR_NOTEXIST, DNS_ERR_NOTIMPL, DNS_ERR_REFUSED};
|
|
|
-
|
|
|
- if (flags & 0x020f || !reply || !reply->have_answer) {
|
|
|
- /* there was an error */
|
|
|
- if (flags & 0x0200) {
|
|
|
- error = DNS_ERR_TRUNCATED;
|
|
|
- } else {
|
|
|
- u16 error_code = (flags & 0x000f) - 1;
|
|
|
- if (error_code > 4) {
|
|
|
- error = DNS_ERR_UNKNOWN;
|
|
|
- } else {
|
|
|
- error = error_codes[error_code];
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- switch(error) {
|
|
|
- case DNS_ERR_NOTIMPL:
|
|
|
- case DNS_ERR_REFUSED:
|
|
|
- /* we regard these errors as marking a bad nameserver */
|
|
|
- if (req->reissue_count < global_max_reissues) {
|
|
|
- char msg[64];
|
|
|
- tor_snprintf(msg, sizeof(msg), "Bad response %d (%s)",
|
|
|
- error, evdns_err_to_string(error));
|
|
|
- nameserver_failed(req->ns, msg);
|
|
|
- if (!request_reissue(req)) return;
|
|
|
- }
|
|
|
- break;
|
|
|
- case DNS_ERR_SERVERFAILED:
|
|
|
- /* rcode 2 (servfailed) sometimes means "we are broken" and
|
|
|
- * sometimes (with some binds) means "that request was very
|
|
|
- * confusing." Treat this as a timeout, not a failure.
|
|
|
- */
|
|
|
- /*XXXX refactor the parts of */
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Got a SERVERFAILED from nameserver %s; "
|
|
|
- "will allow the request to time out.",
|
|
|
- debug_ntop((struct sockaddr *)&req->ns->address));
|
|
|
- break;
|
|
|
- default:
|
|
|
- /* we got a good reply from the nameserver */
|
|
|
- nameserver_up(req->ns);
|
|
|
- }
|
|
|
-
|
|
|
- if (req->search_state && req->request_type != TYPE_PTR) {
|
|
|
- /* if we have a list of domains to search in, try the next one */
|
|
|
- if (!search_try_next(req)) {
|
|
|
- /* a new request was issued so this request is finished and */
|
|
|
- /* the user callback will be made when that request (or a */
|
|
|
- /* child of it) finishes. */
|
|
|
- request_finished(req, &req_head);
|
|
|
- return;
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- /* all else failed. Pass the failure up */
|
|
|
- reply_callback(req, 0, error, NULL);
|
|
|
- request_finished(req, &req_head);
|
|
|
- } else {
|
|
|
- /* all ok, tell the user */
|
|
|
- reply_callback(req, ttl, 0, reply);
|
|
|
- nameserver_up(req->ns);
|
|
|
- request_finished(req, &req_head);
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-static inline int
|
|
|
-name_parse(u8 *packet, int length, int *idx, char *name_out, size_t name_out_len) {
|
|
|
- int name_end = -1;
|
|
|
- int j = *idx;
|
|
|
- int ptr_count = 0;
|
|
|
-#define GET32(x) do { if (j + 4 > length) goto err; memcpy(&_t32, packet + j, 4); j += 4; x = ntohl(_t32); } while(0)
|
|
|
-#define GET16(x) do { if (j + 2 > length) goto err; memcpy(&_t, packet + j, 2); j += 2; x = ntohs(_t); } while(0)
|
|
|
-#define GET8(x) do { if (j >= length) goto err; x = packet[j++]; } while(0)
|
|
|
-
|
|
|
- char *cp = name_out;
|
|
|
- const char *const end = name_out + name_out_len;
|
|
|
-
|
|
|
- /* Normally, names are a series of length prefixed strings terminated */
|
|
|
- /* with a length of 0 (the lengths are u8's < 63). */
|
|
|
- /* However, the length can start with a pair of 1 bits and that */
|
|
|
- /* means that the next 14 bits are a pointer within the current */
|
|
|
- /* packet. */
|
|
|
-
|
|
|
- for(;;) {
|
|
|
- u8 label_len;
|
|
|
- if (j >= length) return -1;
|
|
|
- GET8(label_len);
|
|
|
- if (!label_len) break;
|
|
|
- if (label_len & 0xc0) {
|
|
|
- u8 ptr_low;
|
|
|
- GET8(ptr_low);
|
|
|
- if (name_end < 0) name_end = j;
|
|
|
- j = (((int)label_len & 0x3f) << 8) + ptr_low;
|
|
|
- /* Make sure that the target offset is in-bounds. */
|
|
|
- if (j < 0 || j >= length) return -1;
|
|
|
- /* If we've jumped more times than there are characters in the
|
|
|
- * message, we must have a loop. */
|
|
|
- if (++ptr_count > length) return -1;
|
|
|
- continue;
|
|
|
- }
|
|
|
- if (label_len > 63) return -1;
|
|
|
- if (cp != name_out) {
|
|
|
- if (cp >= name_out + name_out_len - 1) return -1;
|
|
|
- *cp++ = '.';
|
|
|
- }
|
|
|
- if (label_len > name_out_len ||
|
|
|
- cp >= name_out + name_out_len - label_len) return -1;
|
|
|
- memcpy(cp, packet + j, label_len);
|
|
|
- cp += label_len;
|
|
|
- j += label_len;
|
|
|
- }
|
|
|
- if (cp >= end) return -1;
|
|
|
- *cp = '\0';
|
|
|
- if (name_end < 0)
|
|
|
- *idx = j;
|
|
|
- else
|
|
|
- *idx = name_end;
|
|
|
- return 0;
|
|
|
- err:
|
|
|
- return -1;
|
|
|
-}
|
|
|
-
|
|
|
-/* parses a raw reply from a nameserver. */
|
|
|
-static int
|
|
|
-reply_parse(u8 *packet, int length) {
|
|
|
- int j = 0; /* index into packet */
|
|
|
- int k;
|
|
|
- u16 _t; /* used by the macros */
|
|
|
- u32 _t32; /* used by the macros */
|
|
|
- char tmp_name[256], cmp_name[256]; /* used by the macros */
|
|
|
-
|
|
|
- u16 trans_id, questions, answers, authority, additional, datalength;
|
|
|
- u16 flags = 0;
|
|
|
- u32 ttl, ttl_r = 0xffffffff;
|
|
|
- struct reply reply;
|
|
|
- struct evdns_request *req = NULL;
|
|
|
- unsigned int i;
|
|
|
- int name_matches = 0;
|
|
|
-
|
|
|
- GET16(trans_id);
|
|
|
- GET16(flags);
|
|
|
- GET16(questions);
|
|
|
- GET16(answers);
|
|
|
- GET16(authority);
|
|
|
- GET16(additional);
|
|
|
- (void) authority; /* suppress "unused variable" warnings. */
|
|
|
- (void) additional; /* suppress "unused variable" warnings. */
|
|
|
-
|
|
|
- req = request_find_from_trans_id(trans_id);
|
|
|
- /* if no request, can't do anything. */
|
|
|
- if (!req) return -1;
|
|
|
-
|
|
|
- memset(&reply, 0, sizeof(reply));
|
|
|
-
|
|
|
- /* If it's not an answer, it doesn't go with any of our requests. */
|
|
|
- if (!(flags & 0x8000)) return -1; /* must be an answer */
|
|
|
- if (flags & 0x020f) {
|
|
|
- /* there was an error */
|
|
|
- goto err;
|
|
|
- }
|
|
|
- /* if (!answers) return; */ /* must have an answer of some form */
|
|
|
-
|
|
|
- /* This macro skips a name in the DNS reply. */
|
|
|
-#define GET_NAME \
|
|
|
- do { tmp_name[0] = '\0'; \
|
|
|
- if (name_parse(packet, length, &j, tmp_name, sizeof(tmp_name))<0)\
|
|
|
- goto err; \
|
|
|
- } while(0)
|
|
|
-#define TEST_NAME \
|
|
|
- do { tmp_name[0] = '\0'; \
|
|
|
- cmp_name[0] = '\0'; \
|
|
|
- k = j; \
|
|
|
- if (name_parse(packet, length, &j, tmp_name, sizeof(tmp_name))<0)\
|
|
|
- goto err; \
|
|
|
- if (name_parse(req->request, req->request_len, &k, cmp_name, sizeof(cmp_name))<0) \
|
|
|
- goto err; \
|
|
|
- if (global_randomize_case) { \
|
|
|
- if (strcmp(tmp_name, cmp_name) == 0) \
|
|
|
- name_matches = 1; /* we ignore mismatching names */ \
|
|
|
- } else { \
|
|
|
- if (strcasecmp(tmp_name, cmp_name) == 0) \
|
|
|
- name_matches = 1; \
|
|
|
- } \
|
|
|
- } while(0)
|
|
|
-
|
|
|
- reply.type = req->request_type;
|
|
|
-
|
|
|
- /* skip over each question in the reply */
|
|
|
- for (i = 0; i < questions; ++i) {
|
|
|
- /* the question looks like
|
|
|
- * <label:name><u16:type><u16:class>
|
|
|
- */
|
|
|
- TEST_NAME;
|
|
|
- j += 4;
|
|
|
- if (j >= length) goto err;
|
|
|
- }
|
|
|
-
|
|
|
- if (!name_matches)
|
|
|
- goto err;
|
|
|
-
|
|
|
- /* now we have the answer section which looks like
|
|
|
- * <label:name><u16:type><u16:class><u32:ttl><u16:len><data...>
|
|
|
- */
|
|
|
-
|
|
|
- for (i = 0; i < answers; ++i) {
|
|
|
- u16 type, class;
|
|
|
-
|
|
|
- GET_NAME;
|
|
|
- GET16(type);
|
|
|
- GET16(class);
|
|
|
- GET32(ttl);
|
|
|
- GET16(datalength);
|
|
|
-
|
|
|
- if (type == TYPE_A && class == CLASS_INET) {
|
|
|
- int addrcount, addrtocopy;
|
|
|
- if (req->request_type != TYPE_A) {
|
|
|
- j += datalength; continue;
|
|
|
- }
|
|
|
- if ((datalength & 3) != 0) /* not an even number of As. */
|
|
|
- goto err;
|
|
|
- addrcount = datalength >> 2;
|
|
|
- addrtocopy = MIN(MAX_ADDRS - reply.data.a.addrcount, (unsigned)addrcount);
|
|
|
-
|
|
|
- ttl_r = MIN(ttl_r, ttl);
|
|
|
- /* we only bother with the first four addresses. */
|
|
|
- if (j + 4*addrtocopy > length) goto err;
|
|
|
- memcpy(&reply.data.a.addresses[reply.data.a.addrcount],
|
|
|
- packet + j, 4*addrtocopy);
|
|
|
- reply.data.a.addrcount += addrtocopy;
|
|
|
- reply.have_answer = 1;
|
|
|
- if (reply.data.a.addrcount == MAX_ADDRS) break;
|
|
|
- j += 4*addrtocopy;
|
|
|
- } else if (type == TYPE_PTR && class == CLASS_INET) {
|
|
|
- if (req->request_type != TYPE_PTR) {
|
|
|
- j += datalength; continue;
|
|
|
- }
|
|
|
- GET_NAME;
|
|
|
- strlcpy(reply.data.ptr.name, tmp_name,
|
|
|
- sizeof(reply.data.ptr.name));
|
|
|
- ttl_r = MIN(ttl_r, ttl);
|
|
|
- reply.have_answer = 1;
|
|
|
- break;
|
|
|
- } else if (type == TYPE_AAAA && class == CLASS_INET) {
|
|
|
- int addrcount, addrtocopy;
|
|
|
- if (req->request_type != TYPE_AAAA) {
|
|
|
- j += datalength; continue;
|
|
|
- }
|
|
|
- if ((datalength & 15) != 0) /* not an even number of AAAAs. */
|
|
|
- goto err;
|
|
|
- addrcount = datalength >> 4; /* each address is 16 bytes long */
|
|
|
- addrtocopy = MIN(MAX_ADDRS - reply.data.aaaa.addrcount, (unsigned)addrcount);
|
|
|
- ttl_r = MIN(ttl_r, ttl);
|
|
|
-
|
|
|
- /* we only bother with the first four addresses. */
|
|
|
- if (j + 16*addrtocopy > length) goto err;
|
|
|
- memcpy(&reply.data.aaaa.addresses[reply.data.aaaa.addrcount],
|
|
|
- packet + j, 16*addrtocopy);
|
|
|
- reply.data.aaaa.addrcount += addrtocopy;
|
|
|
- reply.have_answer = 1;
|
|
|
- if (reply.data.aaaa.addrcount == MAX_ADDRS) break;
|
|
|
- j += 16*addrtocopy;
|
|
|
- } else {
|
|
|
- /* skip over any other type of resource */
|
|
|
- j += datalength;
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- reply_handle(req, flags, ttl_r, &reply);
|
|
|
- return 0;
|
|
|
- err:
|
|
|
- if (req)
|
|
|
- reply_handle(req, flags, 0, NULL);
|
|
|
- return -1;
|
|
|
-}
|
|
|
-
|
|
|
-/* Parse a raw request (packet,length) sent to a nameserver port (port) from */
|
|
|
-/* a DNS client (addr,addrlen), and if it's well-formed, call the corresponding */
|
|
|
-/* callback. */
|
|
|
-static int
|
|
|
-request_parse(u8 *packet, ssize_t length, struct evdns_server_port *port, struct sockaddr *addr, socklen_t addrlen)
|
|
|
-{
|
|
|
- int j = 0; /* index into packet */
|
|
|
- u16 _t; /* used by the macros */
|
|
|
- char tmp_name[256]; /* used by the macros */
|
|
|
-
|
|
|
- int i;
|
|
|
- u16 trans_id, flags, questions, answers, authority, additional;
|
|
|
- struct server_request *server_req = NULL;
|
|
|
-
|
|
|
- /* Get the header fields */
|
|
|
- GET16(trans_id);
|
|
|
- GET16(flags);
|
|
|
- GET16(questions);
|
|
|
- GET16(answers);
|
|
|
- GET16(authority);
|
|
|
- GET16(additional);
|
|
|
- (void)additional;
|
|
|
- (void)authority;
|
|
|
- (void)answers;
|
|
|
-
|
|
|
- if (flags & 0x8000) return -1; /* Must not be an answer. */
|
|
|
- flags &= 0x0110; /* Only RD and CD get preserved. */
|
|
|
-
|
|
|
- if (length > INT_MAX)
|
|
|
- return -1;
|
|
|
-
|
|
|
- server_req = mm_malloc(sizeof(struct server_request));
|
|
|
- if (server_req == NULL) return -1;
|
|
|
- memset(server_req, 0, sizeof(struct server_request));
|
|
|
-
|
|
|
- server_req->trans_id = trans_id;
|
|
|
- memcpy(&server_req->addr, addr, addrlen);
|
|
|
- server_req->addrlen = addrlen;
|
|
|
-
|
|
|
- server_req->base.flags = flags;
|
|
|
- server_req->base.nquestions = 0;
|
|
|
- server_req->base.questions = mm_malloc(sizeof(struct evdns_server_question *) * questions);
|
|
|
- if (server_req->base.questions == NULL)
|
|
|
- goto err;
|
|
|
-
|
|
|
- for (i = 0; i < questions; ++i) {
|
|
|
- u16 type, class;
|
|
|
- struct evdns_server_question *q;
|
|
|
- size_t namelen;
|
|
|
- if (name_parse(packet, (int)length, &j, tmp_name, sizeof(tmp_name))<0)
|
|
|
- goto err;
|
|
|
- GET16(type);
|
|
|
- GET16(class);
|
|
|
- namelen = strlen(tmp_name);
|
|
|
- q = mm_malloc(sizeof(struct evdns_server_question) + namelen);
|
|
|
- if (!q)
|
|
|
- goto err;
|
|
|
- q->type = type;
|
|
|
- q->dns_question_class = class;
|
|
|
- memcpy(q->name, tmp_name, namelen+1);
|
|
|
- server_req->base.questions[server_req->base.nquestions++] = q;
|
|
|
- }
|
|
|
-
|
|
|
- /* Ignore answers, authority, and additional. */
|
|
|
-
|
|
|
- server_req->port = port;
|
|
|
- port->refcnt++;
|
|
|
-
|
|
|
- /* Only standard queries are supported. */
|
|
|
- if (flags & 0x7800) {
|
|
|
- evdns_server_request_respond(&(server_req->base), DNS_ERR_NOTIMPL);
|
|
|
- return -1;
|
|
|
- }
|
|
|
-
|
|
|
- port->user_callback(&(server_req->base), port->user_data);
|
|
|
-
|
|
|
- return 0;
|
|
|
-err:
|
|
|
- if (server_req) {
|
|
|
- if (server_req->base.questions) {
|
|
|
- for (i = 0; i < server_req->base.nquestions; ++i)
|
|
|
- mm_free(server_req->base.questions[i]);
|
|
|
- mm_free(server_req->base.questions);
|
|
|
- }
|
|
|
- CLEAR(server_req);
|
|
|
- mm_free(server_req);
|
|
|
- }
|
|
|
- return -1;
|
|
|
-
|
|
|
-#undef SKIP_NAME
|
|
|
-#undef GET32
|
|
|
-#undef GET16
|
|
|
-#undef GET8
|
|
|
-}
|
|
|
-
|
|
|
-static uint16_t
|
|
|
-default_transaction_id_fn(void)
|
|
|
-{
|
|
|
- u16 trans_id;
|
|
|
-#ifdef DNS_USE_CPU_CLOCK_FOR_ID
|
|
|
- struct timespec ts;
|
|
|
-#ifdef CLOCK_MONOTONIC
|
|
|
- if (clock_gettime(CLOCK_MONOTONIC, &ts) == -1)
|
|
|
-#else
|
|
|
- if (clock_gettime(CLOCK_REALTIME, &ts) == -1)
|
|
|
-#endif
|
|
|
- event_err(1, "clock_gettime");
|
|
|
- trans_id = ts.tv_nsec & 0xffff;
|
|
|
-#endif
|
|
|
-
|
|
|
-#ifdef DNS_USE_GETTIMEOFDAY_FOR_ID
|
|
|
- struct timeval tv;
|
|
|
- gettimeofday(&tv, NULL);
|
|
|
- trans_id = tv.tv_usec & 0xffff;
|
|
|
-#endif
|
|
|
-
|
|
|
-#ifdef DNS_USE_OPENSSL_FOR_ID
|
|
|
- if (RAND_pseudo_bytes((u8 *) &trans_id, 2) == -1) {
|
|
|
- /* in the case that the RAND call fails we back */
|
|
|
- /* down to using gettimeofday. */
|
|
|
- /*
|
|
|
- struct timeval tv;
|
|
|
- gettimeofday(&tv, NULL);
|
|
|
- trans_id = tv.tv_usec & 0xffff;
|
|
|
- */
|
|
|
- abort();
|
|
|
- }
|
|
|
-#endif
|
|
|
- return (unsigned short) trans_id;
|
|
|
-}
|
|
|
-
|
|
|
-static uint16_t (*trans_id_function)(void) = default_transaction_id_fn;
|
|
|
-
|
|
|
-static void
|
|
|
-default_random_bytes_fn(char *buf, size_t n)
|
|
|
-{
|
|
|
- unsigned i;
|
|
|
- for (i = 0; i < n; i += 2) {
|
|
|
- u16 tid = trans_id_function();
|
|
|
- buf[i] = (tid >> 8) & 0xff;
|
|
|
- if (i+1<n)
|
|
|
- buf[i+1] = tid & 0xff;
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-static void (*rand_bytes_function)(char *buf, size_t n) =
|
|
|
- default_random_bytes_fn;
|
|
|
-
|
|
|
-static u16
|
|
|
-trans_id_from_random_bytes_fn(void)
|
|
|
-{
|
|
|
- u16 tid;
|
|
|
- rand_bytes_function((char*) &tid, sizeof(tid));
|
|
|
- return tid;
|
|
|
-}
|
|
|
-
|
|
|
-void
|
|
|
-evdns_set_transaction_id_fn(uint16_t (*fn)(void))
|
|
|
-{
|
|
|
- if (fn)
|
|
|
- trans_id_function = fn;
|
|
|
- else
|
|
|
- trans_id_function = default_transaction_id_fn;
|
|
|
- rand_bytes_function = default_random_bytes_fn;
|
|
|
-}
|
|
|
-
|
|
|
-void
|
|
|
-evdns_set_random_bytes_fn(void (*fn)(char *, size_t))
|
|
|
-{
|
|
|
- rand_bytes_function = fn;
|
|
|
- trans_id_function = trans_id_from_random_bytes_fn;
|
|
|
-}
|
|
|
-
|
|
|
-/* Try to choose a strong transaction id which isn't already in flight */
|
|
|
-static u16
|
|
|
-transaction_id_pick(void) {
|
|
|
- for (;;) {
|
|
|
- const struct evdns_request *req = req_head, *started_at;
|
|
|
- u16 trans_id = trans_id_function();
|
|
|
-
|
|
|
- if (trans_id == 0xffff) continue;
|
|
|
- /* now check to see if that id is already inflight */
|
|
|
- req = started_at = req_head;
|
|
|
- if (req) {
|
|
|
- do {
|
|
|
- if (req->trans_id == trans_id) break;
|
|
|
- req = req->next;
|
|
|
- } while (req != started_at);
|
|
|
- }
|
|
|
- /* we didn't find it, so this is a good id */
|
|
|
- if (req == started_at) return trans_id;
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* choose a namesever to use. This function will try to ignore */
|
|
|
-/* nameservers which we think are down and load balance across the rest */
|
|
|
-/* by updating the server_head global each time. */
|
|
|
-static struct nameserver *
|
|
|
-nameserver_pick(void) {
|
|
|
- struct nameserver *started_at = server_head, *picked;
|
|
|
- if (!server_head) return NULL;
|
|
|
-
|
|
|
- /* if we don't have any good nameservers then there's no */
|
|
|
- /* point in trying to find one. */
|
|
|
- if (!global_good_nameservers) {
|
|
|
- server_head = server_head->next;
|
|
|
- return server_head;
|
|
|
- }
|
|
|
-
|
|
|
- /* remember that nameservers are in a circular list */
|
|
|
- for (;;) {
|
|
|
- if (server_head->state) {
|
|
|
- /* we think this server is currently good */
|
|
|
- picked = server_head;
|
|
|
- server_head = server_head->next;
|
|
|
- return picked;
|
|
|
- }
|
|
|
-
|
|
|
- server_head = server_head->next;
|
|
|
- if (server_head == started_at) {
|
|
|
- /* all the nameservers seem to be down */
|
|
|
- /* so we just return this one and hope for the */
|
|
|
- /* best */
|
|
|
- assert(global_good_nameservers == 0);
|
|
|
- picked = server_head;
|
|
|
- server_head = server_head->next;
|
|
|
- return picked;
|
|
|
- }
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* this is called when a namesever socket is ready for reading */
|
|
|
-static void
|
|
|
-nameserver_read(struct nameserver *ns) {
|
|
|
- struct sockaddr_storage ss;
|
|
|
- struct sockaddr *sa = (struct sockaddr *) &ss;
|
|
|
- socklen_t addrlen = sizeof(ss);
|
|
|
- u8 packet[1500];
|
|
|
-
|
|
|
- for (;;) {
|
|
|
- const int r =
|
|
|
- (int)recvfrom(ns->socket, (void*)packet,
|
|
|
- (socklen_t)sizeof(packet), 0,
|
|
|
- sa, &addrlen);
|
|
|
- if (r < 0) {
|
|
|
- int err = last_error(ns->socket);
|
|
|
- if (error_is_eagain(err)) return;
|
|
|
- nameserver_failed(ns, tor_socket_strerror(err));
|
|
|
- return;
|
|
|
- }
|
|
|
- /* XXX Match port too? */
|
|
|
- if (!sockaddr_eq(sa, (struct sockaddr*)&ns->address, 0)) {
|
|
|
- evdns_log(EVDNS_LOG_WARN,
|
|
|
- "Address mismatch on received DNS packet. Address was %s",
|
|
|
- debug_ntop(sa));
|
|
|
- return;
|
|
|
- }
|
|
|
- ns->timedout = 0;
|
|
|
- reply_parse(packet, r);
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* Read a packet from a DNS client on a server port s, parse it, and */
|
|
|
-/* act accordingly. */
|
|
|
-static void
|
|
|
-server_port_read(struct evdns_server_port *s) {
|
|
|
- u8 packet[1500];
|
|
|
- struct sockaddr_storage addr;
|
|
|
- socklen_t addrlen;
|
|
|
- ssize_t r;
|
|
|
-
|
|
|
- for (;;) {
|
|
|
- addrlen = (socklen_t)sizeof(struct sockaddr_storage);
|
|
|
- r = recvfrom(s->socket, (void*)packet, sizeof(packet), 0,
|
|
|
- (struct sockaddr*) &addr, &addrlen);
|
|
|
- if (r < 0) {
|
|
|
- int err = last_error(s->socket);
|
|
|
- if (error_is_eagain(err)) return;
|
|
|
- evdns_log(EVDNS_LOG_WARN, "Error %s (%d) while reading request.",
|
|
|
- tor_socket_strerror(err), err);
|
|
|
- return;
|
|
|
- }
|
|
|
- request_parse(packet, r, s, (struct sockaddr*) &addr, addrlen);
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* Try to write all pending replies on a given DNS server port. */
|
|
|
-static void
|
|
|
-server_port_flush(struct evdns_server_port *port)
|
|
|
-{
|
|
|
- struct server_request *req = port->pending_replies;
|
|
|
- while (req) {
|
|
|
- ssize_t r = sendto(port->socket, req->response, req->response_len, 0,
|
|
|
- (struct sockaddr*) &req->addr, (socklen_t)req->addrlen);
|
|
|
- if (r < 0) {
|
|
|
- int err = last_error(port->socket);
|
|
|
- if (error_is_eagain(err))
|
|
|
- return;
|
|
|
- evdns_log(EVDNS_LOG_WARN, "Error %s (%d) while writing response to port; dropping", tor_socket_strerror(err), err);
|
|
|
- }
|
|
|
- if (server_request_free(req)) {
|
|
|
- /* we released the last reference to req->port. */
|
|
|
- return;
|
|
|
- } else {
|
|
|
- assert(port->pending_replies != req);
|
|
|
- req = port->pending_replies;
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- /* We have no more pending requests; stop listening for 'writeable' events. */
|
|
|
- (void) event_del(&port->event);
|
|
|
- CLEAR(&port->event);
|
|
|
- event_set(&port->event, port->socket, EV_READ | EV_PERSIST,
|
|
|
- server_port_ready_callback, port);
|
|
|
- if (event_add(&port->event, NULL) < 0) {
|
|
|
- evdns_log(EVDNS_LOG_WARN, "Error from libevent when adding event for DNS server.");
|
|
|
- /* ???? Do more? */
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* set if we are waiting for the ability to write to this server. */
|
|
|
-/* if waiting is true then we ask libevent for EV_WRITE events, otherwise */
|
|
|
-/* we stop these events. */
|
|
|
-static void
|
|
|
-nameserver_write_waiting(struct nameserver *ns, char waiting) {
|
|
|
- if (ns->write_waiting == waiting) return;
|
|
|
-
|
|
|
- ns->write_waiting = waiting;
|
|
|
- (void) event_del(&ns->event);
|
|
|
- CLEAR(&ns->event);
|
|
|
- event_set(&ns->event, ns->socket, EV_READ | (waiting ? EV_WRITE : 0) | EV_PERSIST,
|
|
|
- nameserver_ready_callback, ns);
|
|
|
- if (event_add(&ns->event, NULL) < 0) {
|
|
|
- evdns_log(EVDNS_LOG_WARN, "Error from libevent when adding event for %s",
|
|
|
- debug_ntop((struct sockaddr *)&ns->address));
|
|
|
- /* ???? Do more? */
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* a callback function. Called by libevent when the kernel says that */
|
|
|
-/* a nameserver socket is ready for writing or reading */
|
|
|
-static void
|
|
|
-nameserver_ready_callback(int fd, short events, void *arg) {
|
|
|
- struct nameserver *ns = (struct nameserver *) arg;
|
|
|
- (void)fd;
|
|
|
-
|
|
|
- if (events & EV_WRITE) {
|
|
|
- ns->choked = 0;
|
|
|
- if (!evdns_transmit()) {
|
|
|
- nameserver_write_waiting(ns, 0);
|
|
|
- }
|
|
|
- }
|
|
|
- if (events & EV_READ) {
|
|
|
- nameserver_read(ns);
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* a callback function. Called by libevent when the kernel says that */
|
|
|
-/* a server socket is ready for writing or reading. */
|
|
|
-static void
|
|
|
-server_port_ready_callback(int fd, short events, void *arg) {
|
|
|
- struct evdns_server_port *port = (struct evdns_server_port *) arg;
|
|
|
- (void) fd;
|
|
|
-
|
|
|
- if (events & EV_WRITE) {
|
|
|
- port->choked = 0;
|
|
|
- server_port_flush(port);
|
|
|
- }
|
|
|
- if (events & EV_READ) {
|
|
|
- server_port_read(port);
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* This is an inefficient representation; only use it via the dnslabel_table_*
|
|
|
- * functions, so that is can be safely replaced with something smarter later. */
|
|
|
-#define MAX_LABELS 128
|
|
|
-/* Structures used to implement name compression */
|
|
|
-struct dnslabel_entry { char *v; off_t pos; };
|
|
|
-struct dnslabel_table {
|
|
|
- int n_labels; /* number of current entries */
|
|
|
- /* map from name to position in message */
|
|
|
- struct dnslabel_entry labels[MAX_LABELS];
|
|
|
-};
|
|
|
-
|
|
|
-/* Initialize dnslabel_table. */
|
|
|
-static void
|
|
|
-dnslabel_table_init(struct dnslabel_table *table)
|
|
|
-{
|
|
|
- table->n_labels = 0;
|
|
|
-}
|
|
|
-
|
|
|
-/* Free all storage held by table, but not the table itself. */
|
|
|
-static void
|
|
|
-dnslabel_clear(struct dnslabel_table *table)
|
|
|
-{
|
|
|
- int i;
|
|
|
- for (i = 0; i < table->n_labels; ++i)
|
|
|
- mm_free(table->labels[i].v);
|
|
|
- table->n_labels = 0;
|
|
|
-}
|
|
|
-
|
|
|
-/* return the position of the label in the current message, or -1 if the label */
|
|
|
-/* hasn't been used yet. */
|
|
|
-static int
|
|
|
-dnslabel_table_get_pos(const struct dnslabel_table *table, const char *label)
|
|
|
-{
|
|
|
- int i;
|
|
|
- for (i = 0; i < table->n_labels; ++i) {
|
|
|
- if (!strcmp(label, table->labels[i].v)) {
|
|
|
- off_t pos = table->labels[i].pos;
|
|
|
- if (pos > 65535)
|
|
|
- return -1;
|
|
|
- return (int)pos;
|
|
|
- }
|
|
|
- }
|
|
|
- return -1;
|
|
|
-}
|
|
|
-
|
|
|
-/* remember that we've used the label at position pos */
|
|
|
-static int
|
|
|
-dnslabel_table_add(struct dnslabel_table *table, const char *label, off_t pos)
|
|
|
-{
|
|
|
- char *v;
|
|
|
- int p;
|
|
|
- if (table->n_labels == MAX_LABELS)
|
|
|
- return (-1);
|
|
|
- v = mm_strdup(label);
|
|
|
- if (v == NULL)
|
|
|
- return (-1);
|
|
|
- p = table->n_labels++;
|
|
|
- table->labels[p].v = v;
|
|
|
- table->labels[p].pos = pos;
|
|
|
-
|
|
|
- return (0);
|
|
|
-}
|
|
|
-
|
|
|
-/* Converts a string to a length-prefixed set of DNS labels, starting */
|
|
|
-/* at buf[j]. name and buf must not overlap. name_len should be the length */
|
|
|
-/* of name. table is optional, and is used for compression. */
|
|
|
-/* */
|
|
|
-/* Input: abc.def */
|
|
|
-/* Output: <3>abc<3>def<0> */
|
|
|
-/* */
|
|
|
-/* Returns the first index after the encoded name, or negative on error. */
|
|
|
-/* -1 label was > 63 bytes */
|
|
|
-/* -2 name too long to fit in buffer. */
|
|
|
-/* */
|
|
|
-static off_t
|
|
|
-dnsname_to_labels(u8 *const buf, size_t buf_len, off_t j,
|
|
|
- const char *name, const size_t name_len,
|
|
|
- struct dnslabel_table *table) {
|
|
|
- const char *end = name + name_len;
|
|
|
- int ref = 0;
|
|
|
- u16 _t;
|
|
|
-
|
|
|
-#define APPEND16(x) do { \
|
|
|
- if (j + 2 > (off_t)buf_len) \
|
|
|
- goto overflow; \
|
|
|
- _t = htons(x); \
|
|
|
- memcpy(buf + j, &_t, 2); \
|
|
|
- j += 2; \
|
|
|
- } while (0)
|
|
|
-#define APPEND32(x) do { \
|
|
|
- if (j + 4 > (off_t)buf_len) \
|
|
|
- goto overflow; \
|
|
|
- _t32 = htonl(x); \
|
|
|
- memcpy(buf + j, &_t32, 4); \
|
|
|
- j += 4; \
|
|
|
- } while (0)
|
|
|
-
|
|
|
- if (name_len > 255) return -2;
|
|
|
-
|
|
|
- for (;;) {
|
|
|
- const char *const start = name;
|
|
|
- if (table && (ref = dnslabel_table_get_pos(table, name)) >= 0) {
|
|
|
- APPEND16(ref | 0xc000);
|
|
|
- return j;
|
|
|
- }
|
|
|
- name = strchr(name, '.');
|
|
|
- if (!name) {
|
|
|
- const size_t label_len = end - start;
|
|
|
- if (label_len > 63) return -1;
|
|
|
- if ((size_t)(j+label_len+1) > buf_len) return -2;
|
|
|
- if (table) dnslabel_table_add(table, start, j);
|
|
|
- buf[j++] = (uint8_t)label_len;
|
|
|
-
|
|
|
- memcpy(buf + j, start, label_len);
|
|
|
- j += end - start;
|
|
|
- break;
|
|
|
- } else {
|
|
|
- /* append length of the label. */
|
|
|
- const size_t label_len = name - start;
|
|
|
- if (label_len > 63) return -1;
|
|
|
- if ((size_t)(j+label_len+1) > buf_len) return -2;
|
|
|
- if (table) dnslabel_table_add(table, start, j);
|
|
|
- buf[j++] = (uint8_t)label_len;
|
|
|
-
|
|
|
- memcpy(buf + j, start, name - start);
|
|
|
- j += name - start;
|
|
|
- /* hop over the '.' */
|
|
|
- name++;
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- /* the labels must be terminated by a 0. */
|
|
|
- /* It's possible that the name ended in a . */
|
|
|
- /* in which case the zero is already there */
|
|
|
- if (!j || buf[j-1]) buf[j++] = 0;
|
|
|
- return j;
|
|
|
- overflow:
|
|
|
- return (-2);
|
|
|
-}
|
|
|
-
|
|
|
-/* Finds the length of a dns request for a DNS name of the given */
|
|
|
-/* length. The actual request may be smaller than the value returned */
|
|
|
-/* here */
|
|
|
-static size_t
|
|
|
-evdns_request_len(const size_t name_len) {
|
|
|
- return 96 + /* length of the DNS standard header */
|
|
|
- name_len + 2 +
|
|
|
- 4; /* space for the resource type */
|
|
|
-}
|
|
|
-
|
|
|
-/* build a dns request packet into buf. buf should be at least as long */
|
|
|
-/* as evdns_request_len told you it should be. */
|
|
|
-/* */
|
|
|
-/* Returns the amount of space used. Negative on error. */
|
|
|
-static int
|
|
|
-evdns_request_data_build(const char *const name, const size_t name_len,
|
|
|
- const u16 trans_id, const u16 type, const u16 class,
|
|
|
- u8 *const buf, size_t buf_len) {
|
|
|
- off_t j = 0; /* current offset into buf */
|
|
|
- u16 _t; /* used by the macros */
|
|
|
-
|
|
|
- APPEND16(trans_id);
|
|
|
- APPEND16(0x0100); /* standard query, recusion needed */
|
|
|
- APPEND16(1); /* one question */
|
|
|
- APPEND16(0); /* no answers */
|
|
|
- APPEND16(0); /* no authority */
|
|
|
- APPEND16(0); /* no additional */
|
|
|
-
|
|
|
- j = dnsname_to_labels(buf, buf_len, j, name, name_len, NULL);
|
|
|
- if (j < 0) {
|
|
|
- return (int)j;
|
|
|
- }
|
|
|
-
|
|
|
- APPEND16(type);
|
|
|
- APPEND16(class);
|
|
|
-
|
|
|
- return (int)j;
|
|
|
- overflow:
|
|
|
- return (-1);
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-struct evdns_server_port *
|
|
|
-evdns_add_server_port(tor_socket_t socket, int is_tcp, evdns_request_callback_fn_type cb, void *user_data)
|
|
|
-{
|
|
|
- struct evdns_server_port *port;
|
|
|
- if (!(port = mm_malloc(sizeof(struct evdns_server_port))))
|
|
|
- return NULL;
|
|
|
- memset(port, 0, sizeof(struct evdns_server_port));
|
|
|
-
|
|
|
- assert(!is_tcp); /* TCP sockets not yet implemented */
|
|
|
- port->socket = socket;
|
|
|
- port->refcnt = 1;
|
|
|
- port->choked = 0;
|
|
|
- port->closing = 0;
|
|
|
- port->user_callback = cb;
|
|
|
- port->user_data = user_data;
|
|
|
- port->pending_replies = NULL;
|
|
|
-
|
|
|
- event_set(&port->event, port->socket, EV_READ | EV_PERSIST,
|
|
|
- server_port_ready_callback, port);
|
|
|
- if (event_add(&port->event, NULL)<0) {
|
|
|
- mm_free(port);
|
|
|
- return NULL;
|
|
|
- }
|
|
|
- return port;
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-void
|
|
|
-evdns_close_server_port(struct evdns_server_port *port)
|
|
|
-{
|
|
|
- port->closing = 1;
|
|
|
- if (--port->refcnt == 0)
|
|
|
- server_port_free(port);
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int
|
|
|
-evdns_server_request_add_reply(struct evdns_server_request *_req, int section, const char *name, int type, int class, int ttl, int datalen, int is_name, const char *data)
|
|
|
-{
|
|
|
- struct server_request *req = TO_SERVER_REQUEST(_req);
|
|
|
- struct server_reply_item **itemp, *item;
|
|
|
- int *countp;
|
|
|
-
|
|
|
- if (req->response) /* have we already answered? */
|
|
|
- return (-1);
|
|
|
-
|
|
|
- switch (section) {
|
|
|
- case EVDNS_ANSWER_SECTION:
|
|
|
- itemp = &req->answer;
|
|
|
- countp = &req->n_answer;
|
|
|
- break;
|
|
|
- case EVDNS_AUTHORITY_SECTION:
|
|
|
- itemp = &req->authority;
|
|
|
- countp = &req->n_authority;
|
|
|
- break;
|
|
|
- case EVDNS_ADDITIONAL_SECTION:
|
|
|
- itemp = &req->additional;
|
|
|
- countp = &req->n_additional;
|
|
|
- break;
|
|
|
- default:
|
|
|
- return (-1);
|
|
|
- }
|
|
|
- while (*itemp) {
|
|
|
- itemp = &((*itemp)->next);
|
|
|
- }
|
|
|
- item = mm_malloc(sizeof(struct server_reply_item));
|
|
|
- if (!item)
|
|
|
- return -1;
|
|
|
- CLEAR(item);
|
|
|
- item->next = NULL;
|
|
|
- if (!(item->name = mm_strdup(name))) {
|
|
|
- CLEAR(item);
|
|
|
- mm_free(item);
|
|
|
- return -1;
|
|
|
- }
|
|
|
- item->type = type;
|
|
|
- item->class = class;
|
|
|
- item->ttl = ttl;
|
|
|
- item->is_name = is_name != 0;
|
|
|
- item->datalen = 0;
|
|
|
- item->data = NULL;
|
|
|
- if (data) {
|
|
|
- if (item->is_name) {
|
|
|
- if (!(item->data = mm_strdup(data))) {
|
|
|
- mm_free(item->name);
|
|
|
- CLEAR(item);
|
|
|
- mm_free(item);
|
|
|
- return -1;
|
|
|
- }
|
|
|
- item->datalen = (u16)-1;
|
|
|
- } else {
|
|
|
- if (!(item->data = mm_malloc(datalen))) {
|
|
|
- mm_free(item->name);
|
|
|
- CLEAR(item);
|
|
|
- mm_free(item);
|
|
|
- return -1;
|
|
|
- }
|
|
|
- item->datalen = datalen;
|
|
|
- memcpy(item->data, data, datalen);
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- *itemp = item;
|
|
|
- ++(*countp);
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int
|
|
|
-evdns_server_request_add_a_reply(struct evdns_server_request *req, const char *name, int n, const void *addrs, int ttl)
|
|
|
-{
|
|
|
- return evdns_server_request_add_reply(
|
|
|
- req, EVDNS_ANSWER_SECTION, name, TYPE_A, CLASS_INET,
|
|
|
- ttl, n*4, 0, addrs);
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int
|
|
|
-evdns_server_request_add_aaaa_reply(struct evdns_server_request *req, const char *name, int n, const void *addrs, int ttl)
|
|
|
-{
|
|
|
- return evdns_server_request_add_reply(
|
|
|
- req, EVDNS_ANSWER_SECTION, name, TYPE_AAAA, CLASS_INET,
|
|
|
- ttl, n*16, 0, addrs);
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int
|
|
|
-evdns_server_request_add_ptr_reply(struct evdns_server_request *req, struct in_addr *in, const char *inaddr_name, const char *hostname, int ttl)
|
|
|
-{
|
|
|
- u32 a;
|
|
|
- char buf[32];
|
|
|
- assert(in || inaddr_name);
|
|
|
- assert(!(in && inaddr_name));
|
|
|
- if (in) {
|
|
|
- a = ntohl(in->s_addr);
|
|
|
- tor_snprintf(buf, sizeof(buf), "%d.%d.%d.%d.in-addr.arpa",
|
|
|
- (int)(u8)((a )&0xff),
|
|
|
- (int)(u8)((a>>8 )&0xff),
|
|
|
- (int)(u8)((a>>16)&0xff),
|
|
|
- (int)(u8)((a>>24)&0xff));
|
|
|
- inaddr_name = buf;
|
|
|
- }
|
|
|
- return evdns_server_request_add_reply(
|
|
|
- req, EVDNS_ANSWER_SECTION, inaddr_name, TYPE_PTR, CLASS_INET,
|
|
|
- ttl, -1, 1, hostname);
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int
|
|
|
-evdns_server_request_add_cname_reply(struct evdns_server_request *req, const char *name, const char *cname, int ttl)
|
|
|
-{
|
|
|
- return evdns_server_request_add_reply(
|
|
|
- req, EVDNS_ANSWER_SECTION, name, TYPE_CNAME, CLASS_INET,
|
|
|
- ttl, -1, 1, cname);
|
|
|
-}
|
|
|
-
|
|
|
-
|
|
|
-static int
|
|
|
-evdns_server_request_format_response(struct server_request *req, int err)
|
|
|
-{
|
|
|
- unsigned char buf[1500];
|
|
|
- size_t buf_len = sizeof(buf);
|
|
|
- off_t j = 0, r;
|
|
|
- u16 _t;
|
|
|
- u32 _t32;
|
|
|
- int i;
|
|
|
- u16 flags;
|
|
|
- struct dnslabel_table table;
|
|
|
-
|
|
|
- if (err < 0 || err > 15) return -1;
|
|
|
-
|
|
|
- /* Set response bit and error code; copy OPCODE and RD fields from
|
|
|
- * question; copy RA and AA if set by caller. */
|
|
|
- flags = req->base.flags;
|
|
|
- flags |= (0x8000 | err);
|
|
|
-
|
|
|
- dnslabel_table_init(&table);
|
|
|
- APPEND16(req->trans_id);
|
|
|
- APPEND16(flags);
|
|
|
- APPEND16(req->base.nquestions);
|
|
|
- APPEND16(req->n_answer);
|
|
|
- APPEND16(req->n_authority);
|
|
|
- APPEND16(req->n_additional);
|
|
|
-
|
|
|
- /* Add questions. */
|
|
|
- for (i=0; i < req->base.nquestions; ++i) {
|
|
|
- const char *s = req->base.questions[i]->name;
|
|
|
- j = dnsname_to_labels(buf, buf_len, j, s, strlen(s), &table);
|
|
|
- if (j < 0) {
|
|
|
- dnslabel_clear(&table);
|
|
|
- return (int) j;
|
|
|
- }
|
|
|
- APPEND16(req->base.questions[i]->type);
|
|
|
- APPEND16(req->base.questions[i]->dns_question_class);
|
|
|
- }
|
|
|
-
|
|
|
- /* Add answer, authority, and additional sections. */
|
|
|
- for (i=0; i<3; ++i) {
|
|
|
- struct server_reply_item *item;
|
|
|
- if (i==0)
|
|
|
- item = req->answer;
|
|
|
- else if (i==1)
|
|
|
- item = req->authority;
|
|
|
- else
|
|
|
- item = req->additional;
|
|
|
- while (item) {
|
|
|
- r = dnsname_to_labels(buf, buf_len, j, item->name, strlen(item->name), &table);
|
|
|
- if (r < 0)
|
|
|
- goto overflow;
|
|
|
- j = r;
|
|
|
-
|
|
|
- APPEND16(item->type);
|
|
|
- APPEND16(item->class);
|
|
|
- APPEND32(item->ttl);
|
|
|
- if (item->is_name) {
|
|
|
- off_t len_idx = j, name_start;
|
|
|
- j += 2;
|
|
|
- name_start = j;
|
|
|
- r = dnsname_to_labels(buf, buf_len, j, item->data, strlen(item->data), &table);
|
|
|
- if (r < 0)
|
|
|
- goto overflow;
|
|
|
- j = r;
|
|
|
- _t = htons( (j-name_start) );
|
|
|
- memcpy(buf+len_idx, &_t, 2);
|
|
|
- } else {
|
|
|
- APPEND16(item->datalen);
|
|
|
- if (j+item->datalen > (off_t)buf_len)
|
|
|
- goto overflow;
|
|
|
- memcpy(buf+j, item->data, item->datalen);
|
|
|
- j += item->datalen;
|
|
|
- }
|
|
|
- item = item->next;
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- if (j > 512) {
|
|
|
-overflow:
|
|
|
- j = 512;
|
|
|
- buf[2] |= 0x02; /* set the truncated bit. */
|
|
|
- }
|
|
|
-
|
|
|
- req->response_len = (size_t)j;
|
|
|
-
|
|
|
- if (!(req->response = mm_malloc(req->response_len))) {
|
|
|
- server_request_free_answers(req);
|
|
|
- dnslabel_clear(&table);
|
|
|
- return (-1);
|
|
|
- }
|
|
|
- memcpy(req->response, buf, req->response_len);
|
|
|
- server_request_free_answers(req);
|
|
|
- dnslabel_clear(&table);
|
|
|
- return (0);
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int
|
|
|
-evdns_server_request_respond(struct evdns_server_request *_req, int err)
|
|
|
-{
|
|
|
- struct server_request *req = TO_SERVER_REQUEST(_req);
|
|
|
- struct evdns_server_port *port = req->port;
|
|
|
- ssize_t r;
|
|
|
- if (!req->response) {
|
|
|
- if ((r = evdns_server_request_format_response(req, err))<0)
|
|
|
- return (int)r;
|
|
|
- }
|
|
|
-
|
|
|
- r = sendto(port->socket, req->response, req->response_len, 0,
|
|
|
- (struct sockaddr*) &req->addr, req->addrlen);
|
|
|
- if (r<0) {
|
|
|
- int error = last_error(port->socket);
|
|
|
- if (! error_is_eagain(error))
|
|
|
- return -1;
|
|
|
-
|
|
|
- if (port->pending_replies) {
|
|
|
- req->prev_pending = port->pending_replies->prev_pending;
|
|
|
- req->next_pending = port->pending_replies;
|
|
|
- req->prev_pending->next_pending =
|
|
|
- req->next_pending->prev_pending = req;
|
|
|
- } else {
|
|
|
- req->prev_pending = req->next_pending = req;
|
|
|
- port->pending_replies = req;
|
|
|
- port->choked = 1;
|
|
|
-
|
|
|
- (void) event_del(&port->event);
|
|
|
- CLEAR(&port->event);
|
|
|
- event_set(&port->event, port->socket, (port->closing?0:EV_READ) | EV_WRITE | EV_PERSIST, server_port_ready_callback, port);
|
|
|
-
|
|
|
- if (event_add(&port->event, NULL) < 0) {
|
|
|
- evdns_log(EVDNS_LOG_WARN, "Error from libevent when adding event for DNS server");
|
|
|
- }
|
|
|
-
|
|
|
- }
|
|
|
-
|
|
|
- return 1;
|
|
|
- }
|
|
|
- if (server_request_free(req))
|
|
|
- return 0;
|
|
|
-
|
|
|
- if (port->pending_replies)
|
|
|
- server_port_flush(port);
|
|
|
-
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-/* Free all storage held by RRs in req. */
|
|
|
-static void
|
|
|
-server_request_free_answers(struct server_request *req)
|
|
|
-{
|
|
|
- struct server_reply_item *victim, *next, **list;
|
|
|
- int i;
|
|
|
- for (i = 0; i < 3; ++i) {
|
|
|
- if (i==0)
|
|
|
- list = &req->answer;
|
|
|
- else if (i==1)
|
|
|
- list = &req->authority;
|
|
|
- else
|
|
|
- list = &req->additional;
|
|
|
-
|
|
|
- victim = *list;
|
|
|
- while (victim) {
|
|
|
- next = victim->next;
|
|
|
- mm_free(victim->name);
|
|
|
- if (victim->data)
|
|
|
- mm_free(victim->data);
|
|
|
- mm_free(victim);
|
|
|
- victim = next;
|
|
|
- }
|
|
|
- *list = NULL;
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* Free all storage held by req, and remove links to it. */
|
|
|
-/* return true iff we just wound up freeing the server_port. */
|
|
|
-static int
|
|
|
-server_request_free(struct server_request *req)
|
|
|
-{
|
|
|
- int i, rc=1;
|
|
|
- if (req->base.questions) {
|
|
|
- for (i = 0; i < req->base.nquestions; ++i)
|
|
|
- mm_free(req->base.questions[i]);
|
|
|
- mm_free(req->base.questions);
|
|
|
- }
|
|
|
-
|
|
|
- if (req->port) {
|
|
|
- if (req->port->pending_replies == req) {
|
|
|
- if (req->next_pending && req->next_pending != req)
|
|
|
- req->port->pending_replies = req->next_pending;
|
|
|
- else
|
|
|
- req->port->pending_replies = NULL;
|
|
|
- }
|
|
|
- rc = --req->port->refcnt;
|
|
|
- }
|
|
|
-
|
|
|
- if (req->response) {
|
|
|
- mm_free(req->response);
|
|
|
- }
|
|
|
-
|
|
|
- server_request_free_answers(req);
|
|
|
-
|
|
|
- if (req->next_pending && req->next_pending != req) {
|
|
|
- req->next_pending->prev_pending = req->prev_pending;
|
|
|
- req->prev_pending->next_pending = req->next_pending;
|
|
|
- }
|
|
|
-
|
|
|
- if (rc == 0) {
|
|
|
- server_port_free(req->port);
|
|
|
- CLEAR(req);
|
|
|
- mm_free(req);
|
|
|
- return (1);
|
|
|
- }
|
|
|
- CLEAR(req);
|
|
|
- mm_free(req);
|
|
|
- return (0);
|
|
|
-}
|
|
|
-
|
|
|
-/* Free all storage held by an evdns_server_port. Only called when the
|
|
|
- * reference count is down to 0. */
|
|
|
-static void
|
|
|
-server_port_free(struct evdns_server_port *port)
|
|
|
-{
|
|
|
- assert(port);
|
|
|
- assert(!port->refcnt);
|
|
|
- assert(!port->pending_replies);
|
|
|
- if (port->socket > 0) {
|
|
|
- CLOSE_SOCKET(port->socket);
|
|
|
- port->socket = -1;
|
|
|
- }
|
|
|
- (void) event_del(&port->event);
|
|
|
- CLEAR(&port->event);
|
|
|
- CLEAR(port);
|
|
|
- mm_free(port);
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int
|
|
|
-evdns_server_request_drop(struct evdns_server_request *_req)
|
|
|
-{
|
|
|
- struct server_request *req = TO_SERVER_REQUEST(_req);
|
|
|
- server_request_free(req);
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int
|
|
|
-evdns_server_request_get_requesting_addr(struct evdns_server_request *_req, struct sockaddr *sa, int addr_len)
|
|
|
-{
|
|
|
- struct server_request *req = TO_SERVER_REQUEST(_req);
|
|
|
- if (addr_len < (int)req->addrlen)
|
|
|
- return -1;
|
|
|
- memcpy(sa, &(req->addr), req->addrlen);
|
|
|
- return req->addrlen;
|
|
|
-}
|
|
|
-
|
|
|
-#undef APPEND16
|
|
|
-#undef APPEND32
|
|
|
-
|
|
|
-/* this is a libevent callback function which is called when a request */
|
|
|
-/* has timed out. */
|
|
|
-static void
|
|
|
-evdns_request_timeout_callback(int fd, short events, void *arg) {
|
|
|
- struct evdns_request *const req = (struct evdns_request *) arg;
|
|
|
- (void) fd;
|
|
|
- (void) events;
|
|
|
-
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Request %lx timed out", (unsigned long) arg);
|
|
|
-
|
|
|
- req->ns->timedout++;
|
|
|
- if (req->ns->timedout > global_max_nameserver_timeout) {
|
|
|
- req->ns->timedout = 0;
|
|
|
- nameserver_failed(req->ns, "request timed out.");
|
|
|
- }
|
|
|
-
|
|
|
- if (req->tx_count >= global_max_retransmits) {
|
|
|
- /* this request has failed */
|
|
|
- reply_callback(req, 0, DNS_ERR_TIMEOUT, NULL);
|
|
|
- request_finished(req, &req_head);
|
|
|
- } else {
|
|
|
- /* retransmit it */
|
|
|
- /* Stop waiting for the timeout. No need to do this in
|
|
|
- * request_finished; that one already deletes the timeout event. */
|
|
|
- del_timeout_event(req);
|
|
|
- evdns_request_transmit(req);
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* try to send a request to a given server. */
|
|
|
-/* */
|
|
|
-/* return: */
|
|
|
-/* 0 ok */
|
|
|
-/* 1 temporary failure */
|
|
|
-/* 2 other failure */
|
|
|
-static int
|
|
|
-evdns_request_transmit_to(struct evdns_request *req, struct nameserver *server) {
|
|
|
- const ssize_t r = send(server->socket, (void*)req->request,
|
|
|
- req->request_len, 0);
|
|
|
- if (r < 0) {
|
|
|
- int err = last_error(server->socket);
|
|
|
- if (error_is_eagain(err)) return 1;
|
|
|
- nameserver_failed(req->ns, tor_socket_strerror(err));
|
|
|
- return 2;
|
|
|
- } else if (r != (ssize_t)req->request_len) {
|
|
|
- return 1; /* short write */
|
|
|
- } else {
|
|
|
- return 0;
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* try to send a request, updating the fields of the request */
|
|
|
-/* as needed */
|
|
|
-/* */
|
|
|
-/* return: */
|
|
|
-/* 0 ok */
|
|
|
-/* 1 failed */
|
|
|
-static int
|
|
|
-evdns_request_transmit(struct evdns_request *req) {
|
|
|
- int retcode = 0, r;
|
|
|
-
|
|
|
- /* if we fail to send this packet then this flag marks it */
|
|
|
- /* for evdns_transmit */
|
|
|
- req->transmit_me = 1;
|
|
|
- if (req->trans_id == 0xffff) abort();
|
|
|
-
|
|
|
- if (req->ns->choked) {
|
|
|
- /* don't bother trying to write to a socket */
|
|
|
- /* which we have had EAGAIN from */
|
|
|
- return 1;
|
|
|
- }
|
|
|
-
|
|
|
- r = evdns_request_transmit_to(req, req->ns);
|
|
|
- switch (r) {
|
|
|
- case 1:
|
|
|
- /* temp failure */
|
|
|
- req->ns->choked = 1;
|
|
|
- nameserver_write_waiting(req->ns, 1);
|
|
|
- return 1;
|
|
|
- case 2:
|
|
|
- /* failed to transmit the request entirely. */
|
|
|
- retcode = 1;
|
|
|
- /* fall through: we'll set a timeout, which will time out,
|
|
|
- * and make us retransmit the request anyway. */
|
|
|
- default:
|
|
|
- /* transmitted; we need to check for timeout. */
|
|
|
- evdns_log(EVDNS_LOG_DEBUG,
|
|
|
- "Setting timeout for request %lx", (unsigned long) req);
|
|
|
-
|
|
|
- if (add_timeout_event(req, &global_timeout) < 0) {
|
|
|
- evdns_log(EVDNS_LOG_WARN,
|
|
|
- "Error from libevent when adding timer for request %lx",
|
|
|
- (unsigned long) req);
|
|
|
- /* ???? Do more? */
|
|
|
- }
|
|
|
- req->tx_count++;
|
|
|
- req->transmit_me = 0;
|
|
|
- return retcode;
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-static void
|
|
|
-nameserver_probe_callback(int result, char type, int count, int ttl, void *addresses, void *arg) {
|
|
|
- struct sockaddr *addr = arg;
|
|
|
- struct nameserver *server;
|
|
|
- (void) type;
|
|
|
- (void) count;
|
|
|
- (void) ttl;
|
|
|
- (void) addresses;
|
|
|
-
|
|
|
- for (server = server_head; server; server = server->next) {
|
|
|
- if (sockaddr_eq(addr, (struct sockaddr*) &server->address, 1)) {
|
|
|
- if (result == DNS_ERR_NONE || result == DNS_ERR_NOTEXIST) {
|
|
|
- /* this is a good reply */
|
|
|
- nameserver_up(server);
|
|
|
- } else {
|
|
|
- nameserver_probe_failed(server);
|
|
|
- }
|
|
|
- }
|
|
|
- if (server->next == server_head)
|
|
|
- break;
|
|
|
- }
|
|
|
-
|
|
|
- mm_free(addr);
|
|
|
-}
|
|
|
-
|
|
|
-static void
|
|
|
-nameserver_send_probe(struct nameserver *const ns) {
|
|
|
- struct evdns_request *req;
|
|
|
- struct sockaddr_storage *addr;
|
|
|
- /* here we need to send a probe to a given nameserver */
|
|
|
- /* in the hope that it is up now. */
|
|
|
-
|
|
|
- /* We identify the nameserver by its address, in case it is removed before
|
|
|
- * our probe comes back. */
|
|
|
- addr = mm_malloc(sizeof(struct sockaddr_storage));
|
|
|
- memcpy(addr, &ns->address, sizeof(struct sockaddr_storage));
|
|
|
-
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Sending probe to %s", debug_ntop((struct sockaddr *)&ns->address));
|
|
|
-
|
|
|
- req = request_new(TYPE_A, "www.google.com", DNS_QUERY_NO_SEARCH, nameserver_probe_callback, addr);
|
|
|
- if (!req) {
|
|
|
- mm_free(addr);
|
|
|
- return;
|
|
|
- }
|
|
|
- /* we force this into the inflight queue no matter what */
|
|
|
- request_trans_id_set(req, transaction_id_pick());
|
|
|
- req->ns = ns;
|
|
|
- request_submit(req);
|
|
|
-}
|
|
|
-
|
|
|
-/* returns: */
|
|
|
-/* 0 didn't try to transmit anything */
|
|
|
-/* 1 tried to transmit something */
|
|
|
-static int
|
|
|
-evdns_transmit(void) {
|
|
|
- char did_try_to_transmit = 0;
|
|
|
-
|
|
|
- if (req_head) {
|
|
|
- struct evdns_request *const started_at = req_head, *req = req_head;
|
|
|
- /* first transmit all the requests which are currently waiting */
|
|
|
- do {
|
|
|
- if (req->transmit_me) {
|
|
|
- did_try_to_transmit = 1;
|
|
|
- evdns_request_transmit(req);
|
|
|
- }
|
|
|
-
|
|
|
- req = req->next;
|
|
|
- } while (req != started_at);
|
|
|
- }
|
|
|
-
|
|
|
- return did_try_to_transmit;
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int
|
|
|
-evdns_count_nameservers(void)
|
|
|
-{
|
|
|
- const struct nameserver *server = server_head;
|
|
|
- int n = 0;
|
|
|
- if (!server)
|
|
|
- return 0;
|
|
|
- do {
|
|
|
- ++n;
|
|
|
- server = server->next;
|
|
|
- } while (server != server_head);
|
|
|
- return n;
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int
|
|
|
-evdns_clear_nameservers_and_suspend(void)
|
|
|
-{
|
|
|
- struct nameserver *server = server_head, *started_at = server_head;
|
|
|
- struct evdns_request *req = req_head, *req_started_at = req_head;
|
|
|
-
|
|
|
- if (!server)
|
|
|
- return 0;
|
|
|
- while (1) {
|
|
|
- struct nameserver *next = server->next;
|
|
|
- (void) event_del(&server->event);
|
|
|
- CLEAR(&server->event);
|
|
|
- del_timeout_event(server);
|
|
|
- if (server->socket >= 0)
|
|
|
- CLOSE_SOCKET(server->socket);
|
|
|
- CLEAR(server);
|
|
|
- mm_free(server);
|
|
|
- if (next == started_at)
|
|
|
- break;
|
|
|
- server = next;
|
|
|
- }
|
|
|
- server_head = NULL;
|
|
|
- global_good_nameservers = 0;
|
|
|
-
|
|
|
- while (req) {
|
|
|
- struct evdns_request *next = req->next;
|
|
|
- req->tx_count = req->reissue_count = 0;
|
|
|
- req->ns = NULL;
|
|
|
- /* ???? What to do about searches? */
|
|
|
- del_timeout_event(req);
|
|
|
- req->trans_id = 0;
|
|
|
- req->transmit_me = 0;
|
|
|
-
|
|
|
- global_requests_waiting++;
|
|
|
- evdns_request_insert(req, &req_waiting_head);
|
|
|
- /* We want to insert these suspended elements at the front of
|
|
|
- * the waiting queue, since they were pending before any of
|
|
|
- * the waiting entries were added. This is a circular list,
|
|
|
- * so we can just shift the start back by one.*/
|
|
|
- req_waiting_head = req_waiting_head->prev;
|
|
|
-
|
|
|
- if (next == req_started_at)
|
|
|
- break;
|
|
|
- req = next;
|
|
|
- }
|
|
|
- req_head = NULL;
|
|
|
- global_requests_inflight = 0;
|
|
|
-
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-static struct sockaddr_storage global_bind_address;
|
|
|
-static socklen_t global_bind_addrlen = 0;
|
|
|
-static int global_bind_addr_is_set = 0;
|
|
|
-void
|
|
|
-evdns_set_default_outgoing_bind_address(const struct sockaddr *addr,
|
|
|
- socklen_t addrlen)
|
|
|
-{
|
|
|
- memset(&global_bind_address, 0, sizeof(global_bind_address));
|
|
|
- if (addr) {
|
|
|
- assert(addrlen <= (socklen_t)sizeof(global_bind_address));
|
|
|
- memcpy(&global_bind_address, addr, addrlen);
|
|
|
- global_bind_addrlen = addrlen;
|
|
|
- global_bind_addr_is_set = 1;
|
|
|
- } else {
|
|
|
- global_bind_addr_is_set = 0;
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int
|
|
|
-evdns_resume(void)
|
|
|
-{
|
|
|
- evdns_requests_pump_waiting_queue();
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-static int
|
|
|
-sockaddr_is_loopback(const struct sockaddr *addr)
|
|
|
-{
|
|
|
- static const char LOOPBACK_S6[16] =
|
|
|
- "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\1";
|
|
|
- if (addr->sa_family == AF_INET) {
|
|
|
- struct sockaddr_in *sin = (struct sockaddr_in *)addr;
|
|
|
- return (ntohl(sin->sin_addr.s_addr) & 0xff000000) == 0x7f000000;
|
|
|
- } else if (addr->sa_family == AF_INET6) {
|
|
|
- struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)addr;
|
|
|
- return fast_memeq(sin6->sin6_addr.s6_addr, LOOPBACK_S6, 16);
|
|
|
- }
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-static int
|
|
|
-_evdns_nameserver_add_impl(const struct sockaddr *address,
|
|
|
- socklen_t addrlen) {
|
|
|
- /* first check to see if we already have this nameserver */
|
|
|
-
|
|
|
- const struct nameserver *server = server_head, *const started_at = server_head;
|
|
|
- struct nameserver *ns;
|
|
|
-
|
|
|
- int err = 0;
|
|
|
- if (server) {
|
|
|
- do {
|
|
|
- if (sockaddr_eq(address, (struct sockaddr *)&server->address, 1)) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Duplicate nameserver.");
|
|
|
- return 3;
|
|
|
- }
|
|
|
- server = server->next;
|
|
|
- } while (server != started_at);
|
|
|
- }
|
|
|
- if (addrlen > (int)sizeof(ns->address)) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Addrlen %d too long.", (int)addrlen);
|
|
|
- return 2;
|
|
|
- }
|
|
|
-
|
|
|
- ns = (struct nameserver *) mm_malloc(sizeof(struct nameserver));
|
|
|
- if (!ns) return -1;
|
|
|
-
|
|
|
- memset(ns, 0, sizeof(struct nameserver));
|
|
|
-
|
|
|
- evtimer_set(&ns->timeout_event, nameserver_prod_callback, ns);
|
|
|
-
|
|
|
-#if 1
|
|
|
- ns->socket = tor_open_socket_nonblocking(address->sa_family, SOCK_DGRAM, 0);
|
|
|
- if (!SOCKET_OK(ns->socket)) { err = 1; goto out1; }
|
|
|
-#else
|
|
|
- ns->socket = tor_open_socket(address->sa_family, SOCK_DGRAM, 0);
|
|
|
- if (ns->socket < 0) { err = 1; goto out1; }
|
|
|
-#ifdef _WIN32
|
|
|
- {
|
|
|
- u_long nonblocking = 1;
|
|
|
- ioctlsocket(ns->socket, FIONBIO, &nonblocking);
|
|
|
- }
|
|
|
-#else
|
|
|
- if (fcntl(ns->socket, F_SETFL, O_NONBLOCK) == -1) {
|
|
|
- evdns_log(EVDNS_LOG_WARN, "Error %s (%d) while settings file status flags.",
|
|
|
- tor_socket_strerror(errno), errno);
|
|
|
- err = 2;
|
|
|
- goto out2;
|
|
|
- }
|
|
|
-#endif
|
|
|
-
|
|
|
-#endif /* 1 */
|
|
|
- if (global_bind_addr_is_set &&
|
|
|
- !sockaddr_is_loopback((struct sockaddr*)&global_bind_address)) {
|
|
|
- if (bind(ns->socket, (struct sockaddr *)&global_bind_address,
|
|
|
- global_bind_addrlen) < 0) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Couldn't bind to outgoing address.");
|
|
|
- err = 2;
|
|
|
- goto out2;
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- if (connect(ns->socket, address, addrlen) != 0) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Couldn't open socket to nameserver.");
|
|
|
- err = 2;
|
|
|
- goto out2;
|
|
|
- }
|
|
|
-
|
|
|
- memcpy(&ns->address, address, addrlen);
|
|
|
- ns->state = 1;
|
|
|
- event_set(&ns->event, ns->socket, EV_READ | EV_PERSIST, nameserver_ready_callback, ns);
|
|
|
- if (event_add(&ns->event, NULL) < 0) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Couldn't add event for nameserver.");
|
|
|
- err = 2;
|
|
|
- goto out2;
|
|
|
- }
|
|
|
-
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Added nameserver %s", debug_ntop(address));
|
|
|
-
|
|
|
- /* insert this nameserver into the list of them */
|
|
|
- if (!server_head) {
|
|
|
- ns->next = ns->prev = ns;
|
|
|
- server_head = ns;
|
|
|
- } else {
|
|
|
- ns->next = server_head->next;
|
|
|
- ns->prev = server_head;
|
|
|
- server_head->next = ns;
|
|
|
- if (server_head->prev == server_head) {
|
|
|
- server_head->prev = ns;
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- global_good_nameservers++;
|
|
|
-
|
|
|
- return 0;
|
|
|
-
|
|
|
-out2:
|
|
|
- CLOSE_SOCKET(ns->socket);
|
|
|
-out1:
|
|
|
- CLEAR(ns);
|
|
|
- mm_free(ns);
|
|
|
- evdns_log(EVDNS_LOG_WARN, "Unable to add nameserver %s: error %d", debug_ntop(address), err);
|
|
|
- return err;
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int
|
|
|
-evdns_nameserver_add(uint32_t address) {
|
|
|
- struct sockaddr_in sin;
|
|
|
- memset(&sin, 0, sizeof(sin));
|
|
|
- sin.sin_family = AF_INET;
|
|
|
-#ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
|
|
|
- sin.sin_len = sizeof(sin);
|
|
|
-#endif
|
|
|
- sin.sin_addr.s_addr = htonl(address);
|
|
|
- sin.sin_port = 53;
|
|
|
- return _evdns_nameserver_add_impl((struct sockaddr*) &sin, sizeof(sin));
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int
|
|
|
-evdns_nameserver_ip_add(const char *ip_as_string) {
|
|
|
- int port;
|
|
|
- char buf[128];
|
|
|
- const char *cp, *addr_part, *port_part;
|
|
|
- int is_ipv6;
|
|
|
- /* recognized formats are:
|
|
|
- * [ipv6]:port
|
|
|
- * ipv6
|
|
|
- * [ipv6]
|
|
|
- * ipv4:port
|
|
|
- * ipv4
|
|
|
- */
|
|
|
-
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Trying to add nameserver <%s>", ip_as_string);
|
|
|
-
|
|
|
- cp = strchr(ip_as_string, ':');
|
|
|
- if (*ip_as_string == '[') {
|
|
|
- size_t len;
|
|
|
- if (!(cp = strchr(ip_as_string, ']'))) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Nameserver missing closing ]");
|
|
|
- return 4;
|
|
|
- }
|
|
|
- len = cp-(ip_as_string + 1);
|
|
|
- if (len > sizeof(buf)-1) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "[Nameserver] does not fit in buffer.");
|
|
|
- return 4;
|
|
|
- }
|
|
|
- memcpy(buf, ip_as_string+1, len);
|
|
|
- buf[len] = '\0';
|
|
|
- addr_part = buf;
|
|
|
- if (cp[1] == ':')
|
|
|
- port_part = cp+2;
|
|
|
- else
|
|
|
- port_part = NULL;
|
|
|
- is_ipv6 = 1;
|
|
|
- } else if (cp && strchr(cp+1, ':')) {
|
|
|
- is_ipv6 = 1;
|
|
|
- addr_part = ip_as_string;
|
|
|
- port_part = NULL;
|
|
|
- } else if (cp) {
|
|
|
- is_ipv6 = 0;
|
|
|
- if (cp - ip_as_string > (int)sizeof(buf)-1) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Nameserver does not fit in buffer.");
|
|
|
- return 4;
|
|
|
- }
|
|
|
- memcpy(buf, ip_as_string, cp-ip_as_string);
|
|
|
- buf[cp-ip_as_string] = '\0';
|
|
|
- addr_part = buf;
|
|
|
- port_part = cp+1;
|
|
|
- } else {
|
|
|
- addr_part = ip_as_string;
|
|
|
- port_part = NULL;
|
|
|
- is_ipv6 = 0;
|
|
|
- }
|
|
|
-
|
|
|
- if (port_part == NULL) {
|
|
|
- port = 53;
|
|
|
- } else {
|
|
|
- port = strtoint(port_part);
|
|
|
- if (port <= 0 || port > 65535) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Nameserver port <%s> out of range",
|
|
|
- port_part);
|
|
|
- return 4;
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- /* Tor-only. needs a more general fix. */
|
|
|
- assert(addr_part);
|
|
|
- if (is_ipv6) {
|
|
|
- struct sockaddr_in6 sin6;
|
|
|
- memset(&sin6, 0, sizeof(sin6));
|
|
|
-#ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_LEN
|
|
|
- sin6.sin6_len = sizeof(sin6);
|
|
|
-#endif
|
|
|
- sin6.sin6_family = AF_INET6;
|
|
|
- sin6.sin6_port = htons(port);
|
|
|
- if (1 != tor_inet_pton(AF_INET6, addr_part, &sin6.sin6_addr)) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "inet_pton(%s) failed", addr_part);
|
|
|
- return 4;
|
|
|
- }
|
|
|
- return _evdns_nameserver_add_impl((struct sockaddr*)&sin6,
|
|
|
- sizeof(sin6));
|
|
|
- } else {
|
|
|
- struct sockaddr_in sin;
|
|
|
- memset(&sin, 0, sizeof(sin));
|
|
|
-#ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
|
|
|
- sin.sin_len = sizeof(sin);
|
|
|
-#endif
|
|
|
- sin.sin_family = AF_INET;
|
|
|
- sin.sin_port = htons(port);
|
|
|
- if (!inet_aton(addr_part, &sin.sin_addr)) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "inet_pton(%s) failed", addr_part);
|
|
|
- return 4;
|
|
|
- }
|
|
|
- return _evdns_nameserver_add_impl((struct sockaddr*)&sin,
|
|
|
- sizeof(sin));
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-int
|
|
|
-evdns_nameserver_sockaddr_add(const struct sockaddr *sa, socklen_t len)
|
|
|
-{
|
|
|
- return _evdns_nameserver_add_impl(sa, len);
|
|
|
-}
|
|
|
-
|
|
|
-/* insert into the tail of the queue */
|
|
|
-static void
|
|
|
-evdns_request_insert(struct evdns_request *req, struct evdns_request **head) {
|
|
|
- if (!*head) {
|
|
|
- *head = req;
|
|
|
- req->next = req->prev = req;
|
|
|
- return;
|
|
|
- }
|
|
|
-
|
|
|
- req->prev = (*head)->prev;
|
|
|
- req->prev->next = req;
|
|
|
- req->next = *head;
|
|
|
- (*head)->prev = req;
|
|
|
-}
|
|
|
-
|
|
|
-static int
|
|
|
-string_num_dots(const char *s) {
|
|
|
- int count = 0;
|
|
|
- while ((s = strchr(s, '.'))) {
|
|
|
- s++;
|
|
|
- count++;
|
|
|
- }
|
|
|
- return count;
|
|
|
-}
|
|
|
-
|
|
|
-static struct evdns_request *
|
|
|
-request_new(int type, const char *name, int flags,
|
|
|
- evdns_callback_type callback, void *user_ptr) {
|
|
|
- const char issuing_now =
|
|
|
- (global_requests_inflight < global_max_requests_inflight) ? 1 : 0;
|
|
|
-
|
|
|
- const size_t name_len = strlen(name);
|
|
|
- const size_t request_max_len = evdns_request_len(name_len);
|
|
|
- const u16 trans_id = issuing_now ? transaction_id_pick() : 0xffff;
|
|
|
- /* the request data is alloced in a single block with the header */
|
|
|
- struct evdns_request *const req =
|
|
|
- (struct evdns_request *) mm_malloc(sizeof(struct evdns_request) + request_max_len);
|
|
|
- char namebuf[256];
|
|
|
- int rlen;
|
|
|
- (void) flags;
|
|
|
-
|
|
|
- if (!req) return NULL;
|
|
|
-
|
|
|
- if (name_len >= sizeof(namebuf)) {
|
|
|
- _mm_free(req);
|
|
|
- return NULL;
|
|
|
- }
|
|
|
-
|
|
|
- memset(req, 0, sizeof(struct evdns_request));
|
|
|
-
|
|
|
- evtimer_set(&req->timeout_event, evdns_request_timeout_callback, req);
|
|
|
-
|
|
|
- if (global_randomize_case) {
|
|
|
- unsigned i;
|
|
|
- char randbits[32];
|
|
|
- strlcpy(namebuf, name, sizeof(namebuf));
|
|
|
- rand_bytes_function(randbits, (name_len+7)/8);
|
|
|
- for (i = 0; i < name_len; ++i) {
|
|
|
- if (ISALPHA(namebuf[i])) {
|
|
|
- if ((randbits[i >> 3] & (1<<(i%7))))
|
|
|
- namebuf[i] = TOLOWER(namebuf[i]);
|
|
|
- else
|
|
|
- namebuf[i] = TOUPPER(namebuf[i]);
|
|
|
- }
|
|
|
- }
|
|
|
- name = namebuf;
|
|
|
- }
|
|
|
-
|
|
|
- /* request data lives just after the header */
|
|
|
- req->request = ((u8 *) req) + sizeof(struct evdns_request);
|
|
|
- /* denotes that the request data shouldn't be mm_free()ed */
|
|
|
- req->request_appended = 1;
|
|
|
- rlen = evdns_request_data_build(name, name_len, trans_id,
|
|
|
- type, CLASS_INET, req->request, request_max_len);
|
|
|
- if (rlen < 0)
|
|
|
- goto err1;
|
|
|
- req->request_len = rlen;
|
|
|
- req->trans_id = trans_id;
|
|
|
- req->tx_count = 0;
|
|
|
- req->request_type = type;
|
|
|
- req->user_pointer = user_ptr;
|
|
|
- req->user_callback = callback;
|
|
|
- req->ns = issuing_now ? nameserver_pick() : NULL;
|
|
|
- req->next = req->prev = NULL;
|
|
|
-
|
|
|
- return req;
|
|
|
-err1:
|
|
|
- CLEAR(req);
|
|
|
- _mm_free(req);
|
|
|
- return NULL;
|
|
|
-}
|
|
|
-
|
|
|
-static void
|
|
|
-request_submit(struct evdns_request *const req) {
|
|
|
- if (req->ns) {
|
|
|
- /* if it has a nameserver assigned then this is going */
|
|
|
- /* straight into the inflight queue */
|
|
|
- evdns_request_insert(req, &req_head);
|
|
|
- global_requests_inflight++;
|
|
|
- evdns_request_transmit(req);
|
|
|
- } else {
|
|
|
- evdns_request_insert(req, &req_waiting_head);
|
|
|
- global_requests_waiting++;
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int evdns_resolve_ipv4(const char *name, int flags,
|
|
|
- evdns_callback_type callback, void *ptr) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Resolve requested for %s", name);
|
|
|
- if (flags & DNS_QUERY_NO_SEARCH) {
|
|
|
- struct evdns_request *const req =
|
|
|
- request_new(TYPE_A, name, flags, callback, ptr);
|
|
|
- if (req == NULL)
|
|
|
- return (1);
|
|
|
- request_submit(req);
|
|
|
- return (0);
|
|
|
- } else {
|
|
|
- return (search_request_new(TYPE_A, name, flags, callback, ptr));
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int evdns_resolve_ipv6(const char *name, int flags,
|
|
|
- evdns_callback_type callback, void *ptr) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Resolve requested for %s", name);
|
|
|
- if (flags & DNS_QUERY_NO_SEARCH) {
|
|
|
- struct evdns_request *const req =
|
|
|
- request_new(TYPE_AAAA, name, flags, callback, ptr);
|
|
|
- if (req == NULL)
|
|
|
- return (1);
|
|
|
- request_submit(req);
|
|
|
- return (0);
|
|
|
- } else {
|
|
|
- return (search_request_new(TYPE_AAAA, name, flags, callback, ptr));
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-int evdns_resolve_reverse(const struct in_addr *in, int flags, evdns_callback_type callback, void *ptr) {
|
|
|
- char buf[32];
|
|
|
- struct evdns_request *req;
|
|
|
- u32 a;
|
|
|
- assert(in);
|
|
|
- a = ntohl(in->s_addr);
|
|
|
- tor_snprintf(buf, sizeof(buf), "%d.%d.%d.%d.in-addr.arpa",
|
|
|
- (int)(u8)((a )&0xff),
|
|
|
- (int)(u8)((a>>8 )&0xff),
|
|
|
- (int)(u8)((a>>16)&0xff),
|
|
|
- (int)(u8)((a>>24)&0xff));
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Resolve requested for %s (reverse)", buf);
|
|
|
- req = request_new(TYPE_PTR, buf, flags, callback, ptr);
|
|
|
- if (!req) return 1;
|
|
|
- request_submit(req);
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-int evdns_resolve_reverse_ipv6(const struct in6_addr *in, int flags, evdns_callback_type callback, void *ptr) {
|
|
|
- /* 32 nybbles, 32 periods, "ip6.arpa", NUL. */
|
|
|
- char buf[73];
|
|
|
- char *cp;
|
|
|
- struct evdns_request *req;
|
|
|
- int i;
|
|
|
- assert(in);
|
|
|
- cp = buf;
|
|
|
- for (i=15; i >= 0; --i) {
|
|
|
- u8 byte = in->s6_addr[i];
|
|
|
- *cp++ = "0123456789abcdef"[byte & 0x0f];
|
|
|
- *cp++ = '.';
|
|
|
- *cp++ = "0123456789abcdef"[byte >> 4];
|
|
|
- *cp++ = '.';
|
|
|
- }
|
|
|
- assert(cp + strlen("ip6.arpa") < buf+sizeof(buf));
|
|
|
- memcpy(cp, "ip6.arpa", strlen("ip6.arpa")+1);
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Resolve requested for %s (reverse)", buf);
|
|
|
- req = request_new(TYPE_PTR, buf, flags, callback, ptr);
|
|
|
- if (!req) return 1;
|
|
|
- request_submit(req);
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-/*/////////////////////////////////////////////////////////////////// */
|
|
|
-/* Search support */
|
|
|
-/* */
|
|
|
-/* the libc resolver has support for searching a number of domains */
|
|
|
-/* to find a name. If nothing else then it takes the single domain */
|
|
|
-/* from the gethostname() call. */
|
|
|
-/* */
|
|
|
-/* It can also be configured via the domain and search options in a */
|
|
|
-/* resolv.conf. */
|
|
|
-/* */
|
|
|
-/* The ndots option controls how many dots it takes for the resolver */
|
|
|
-/* to decide that a name is non-local and so try a raw lookup first. */
|
|
|
-
|
|
|
-struct search_domain {
|
|
|
- size_t len;
|
|
|
- struct search_domain *next;
|
|
|
- /* the text string is appended to this structure */
|
|
|
-};
|
|
|
-
|
|
|
-struct search_state {
|
|
|
- int refcount;
|
|
|
- int ndots;
|
|
|
- int num_domains;
|
|
|
- struct search_domain *head;
|
|
|
-};
|
|
|
-
|
|
|
-static struct search_state *global_search_state = NULL;
|
|
|
-
|
|
|
-static void
|
|
|
-search_state_decref(struct search_state *const state) {
|
|
|
- if (!state) return;
|
|
|
- state->refcount--;
|
|
|
- if (!state->refcount) {
|
|
|
- struct search_domain *next, *dom;
|
|
|
- for (dom = state->head; dom; dom = next) {
|
|
|
- next = dom->next;
|
|
|
- CLEAR(dom);
|
|
|
- _mm_free(dom);
|
|
|
- }
|
|
|
- CLEAR(state);
|
|
|
- _mm_free(state);
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-static struct search_state *
|
|
|
-search_state_new(void) {
|
|
|
- struct search_state *state = (struct search_state *) mm_malloc(sizeof(struct search_state));
|
|
|
- if (!state) return NULL;
|
|
|
- memset(state, 0, sizeof(struct search_state));
|
|
|
- state->refcount = 1;
|
|
|
- state->ndots = 1;
|
|
|
-
|
|
|
- return state;
|
|
|
-}
|
|
|
-
|
|
|
-static void
|
|
|
-search_postfix_clear(void) {
|
|
|
- search_state_decref(global_search_state);
|
|
|
-
|
|
|
- global_search_state = search_state_new();
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-void
|
|
|
-evdns_search_clear(void) {
|
|
|
- search_postfix_clear();
|
|
|
-}
|
|
|
-
|
|
|
-static void
|
|
|
-search_postfix_add(const char *domain) {
|
|
|
- size_t domain_len;
|
|
|
- struct search_domain *sdomain;
|
|
|
- while (domain[0] == '.') domain++;
|
|
|
- domain_len = strlen(domain);
|
|
|
-
|
|
|
- if (!global_search_state) global_search_state = search_state_new();
|
|
|
- if (!global_search_state) return;
|
|
|
- global_search_state->num_domains++;
|
|
|
-
|
|
|
- sdomain = (struct search_domain *) mm_malloc(sizeof(struct search_domain) + domain_len);
|
|
|
- if (!sdomain) return;
|
|
|
- memcpy( ((u8 *) sdomain) + sizeof(struct search_domain), domain, domain_len);
|
|
|
- sdomain->next = global_search_state->head;
|
|
|
- sdomain->len = domain_len;
|
|
|
-
|
|
|
- global_search_state->head = sdomain;
|
|
|
-}
|
|
|
-
|
|
|
-/* reverse the order of members in the postfix list. This is needed because, */
|
|
|
-/* when parsing resolv.conf we push elements in the wrong order */
|
|
|
-static void
|
|
|
-search_reverse(void) {
|
|
|
- struct search_domain *cur, *prev = NULL, *next;
|
|
|
- cur = global_search_state->head;
|
|
|
- while (cur) {
|
|
|
- next = cur->next;
|
|
|
- cur->next = prev;
|
|
|
- prev = cur;
|
|
|
- cur = next;
|
|
|
- }
|
|
|
-
|
|
|
- global_search_state->head = prev;
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-void
|
|
|
-evdns_search_add(const char *domain) {
|
|
|
- search_postfix_add(domain);
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-void
|
|
|
-evdns_search_ndots_set(const int ndots) {
|
|
|
- if (!global_search_state) global_search_state = search_state_new();
|
|
|
- if (!global_search_state) return;
|
|
|
- global_search_state->ndots = ndots;
|
|
|
-}
|
|
|
-
|
|
|
-static void
|
|
|
-search_set_from_hostname(void) {
|
|
|
- char hostname[HOST_NAME_MAX + 1], *domainname;
|
|
|
-
|
|
|
- search_postfix_clear();
|
|
|
- if (gethostname(hostname, sizeof(hostname))) return;
|
|
|
- domainname = strchr(hostname, '.');
|
|
|
- if (!domainname) return;
|
|
|
- search_postfix_add(domainname);
|
|
|
-}
|
|
|
-
|
|
|
-/* warning: returns malloced string */
|
|
|
-static char *
|
|
|
-search_make_new(const struct search_state *const state, int n, const char *const base_name) {
|
|
|
- const size_t base_len = strlen(base_name);
|
|
|
- const char need_to_append_dot = base_name[base_len - 1] == '.' ? 0 : 1;
|
|
|
- struct search_domain *dom;
|
|
|
-
|
|
|
- for (dom = state->head; dom; dom = dom->next) {
|
|
|
- if (!n--) {
|
|
|
- /* this is the postfix we want */
|
|
|
- /* the actual postfix string is kept at the end of the structure */
|
|
|
- const u8 *const postfix = ((u8 *) dom) + sizeof(struct search_domain);
|
|
|
- const size_t postfix_len = dom->len;
|
|
|
- char *const newname = (char *) mm_malloc(base_len + need_to_append_dot + postfix_len + 1);
|
|
|
- if (!newname) return NULL;
|
|
|
- memcpy(newname, base_name, base_len);
|
|
|
- if (need_to_append_dot) newname[base_len] = '.';
|
|
|
- memcpy(newname + base_len + need_to_append_dot, postfix, postfix_len);
|
|
|
- newname[base_len + need_to_append_dot + postfix_len] = 0;
|
|
|
- return newname;
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- /* we ran off the end of the list and still didn't find the requested string */
|
|
|
- abort();
|
|
|
- return NULL; /* unreachable; stops warnings in some compilers. */
|
|
|
-}
|
|
|
-
|
|
|
-static int
|
|
|
-search_request_new(int type, const char *const name, int flags, evdns_callback_type user_callback, void *user_arg) {
|
|
|
- assert(type == TYPE_A || type == TYPE_AAAA);
|
|
|
- if ( ((flags & DNS_QUERY_NO_SEARCH) == 0) &&
|
|
|
- global_search_state &&
|
|
|
- global_search_state->num_domains) {
|
|
|
- /* we have some domains to search */
|
|
|
- struct evdns_request *req;
|
|
|
- if (string_num_dots(name) >= global_search_state->ndots) {
|
|
|
- req = request_new(type, name, flags, user_callback, user_arg);
|
|
|
- if (!req) return 1;
|
|
|
- req->search_index = -1;
|
|
|
- } else {
|
|
|
- char *const new_name = search_make_new(global_search_state, 0, name);
|
|
|
- if (!new_name) return 1;
|
|
|
- req = request_new(type, new_name, flags, user_callback, user_arg);
|
|
|
- _mm_free(new_name);
|
|
|
- if (!req) return 1;
|
|
|
- req->search_index = 0;
|
|
|
- }
|
|
|
- req->search_origname = mm_strdup(name);
|
|
|
- req->search_state = global_search_state;
|
|
|
- req->search_flags = flags;
|
|
|
- global_search_state->refcount++;
|
|
|
- request_submit(req);
|
|
|
- return 0;
|
|
|
- } else {
|
|
|
- struct evdns_request *const req = request_new(type, name, flags, user_callback, user_arg);
|
|
|
- if (!req) return 1;
|
|
|
- request_submit(req);
|
|
|
- return 0;
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/* this is called when a request has failed to find a name. We need to check */
|
|
|
-/* if it is part of a search and, if so, try the next name in the list */
|
|
|
-/* returns: */
|
|
|
-/* 0 another request has been submitted */
|
|
|
-/* 1 no more requests needed */
|
|
|
-static int
|
|
|
-search_try_next(struct evdns_request *const req) {
|
|
|
- if (req->search_state) {
|
|
|
- /* it is part of a search */
|
|
|
- char *new_name;
|
|
|
- struct evdns_request *newreq;
|
|
|
- req->search_index++;
|
|
|
- if (req->search_index >= req->search_state->num_domains) {
|
|
|
- /* no more postfixes to try, however we may need to try */
|
|
|
- /* this name without a postfix */
|
|
|
- if (string_num_dots(req->search_origname) < req->search_state->ndots) {
|
|
|
- /* yep, we need to try it raw */
|
|
|
- struct evdns_request *const newreq = request_new(req->request_type, req->search_origname, req->search_flags, req->user_callback, req->user_pointer);
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Search: trying raw query %s", req->search_origname);
|
|
|
- if (newreq) {
|
|
|
- request_submit(newreq);
|
|
|
- return 0;
|
|
|
- }
|
|
|
- }
|
|
|
- return 1;
|
|
|
- }
|
|
|
-
|
|
|
- new_name = search_make_new(req->search_state, req->search_index, req->search_origname);
|
|
|
- if (!new_name) return 1;
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Search: now trying %s (%d)", new_name, req->search_index);
|
|
|
- newreq = request_new(req->request_type, new_name, req->search_flags, req->user_callback, req->user_pointer);
|
|
|
- mm_free(new_name);
|
|
|
- if (!newreq) return 1;
|
|
|
- newreq->search_origname = req->search_origname;
|
|
|
- req->search_origname = NULL;
|
|
|
- newreq->search_state = req->search_state;
|
|
|
- newreq->search_flags = req->search_flags;
|
|
|
- newreq->search_index = req->search_index;
|
|
|
- newreq->search_state->refcount++;
|
|
|
- request_submit(newreq);
|
|
|
- return 0;
|
|
|
- }
|
|
|
- return 1;
|
|
|
-}
|
|
|
-
|
|
|
-static void
|
|
|
-search_request_finished(struct evdns_request *const req) {
|
|
|
- if (req->search_state) {
|
|
|
- search_state_decref(req->search_state);
|
|
|
- req->search_state = NULL;
|
|
|
- }
|
|
|
- if (req->search_origname) {
|
|
|
- mm_free(req->search_origname);
|
|
|
- req->search_origname = NULL;
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-/*/////////////////////////////////////////////////////////////////// */
|
|
|
-/* Parsing resolv.conf files */
|
|
|
-
|
|
|
-static void
|
|
|
-evdns_resolv_set_defaults(int flags) {
|
|
|
- /* if the file isn't found then we assume a local resolver */
|
|
|
- if (flags & DNS_OPTION_SEARCH) search_set_from_hostname();
|
|
|
- if (flags & DNS_OPTION_NAMESERVERS) evdns_nameserver_ip_add("127.0.0.1");
|
|
|
-}
|
|
|
-
|
|
|
-/* helper version of atoi which returns -1 on error */
|
|
|
-static int
|
|
|
-strtoint(const char *const str) {
|
|
|
- char *endptr;
|
|
|
- const long r = strtol(str, &endptr, 10);
|
|
|
- if (*endptr || r > INT_MAX) return -1;
|
|
|
- return (int)r;
|
|
|
-}
|
|
|
-
|
|
|
-/* helper version of atoi that returns -1 on error and clips to bounds. */
|
|
|
-static int
|
|
|
-strtoint_clipped(const char *const str, int min, int max)
|
|
|
-{
|
|
|
- int r = strtoint(str);
|
|
|
- if (r == -1)
|
|
|
- return r;
|
|
|
- else if (r<min)
|
|
|
- return min;
|
|
|
- else if (r>max)
|
|
|
- return max;
|
|
|
- else
|
|
|
- return r;
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-int
|
|
|
-evdns_set_option(const char *option, const char *val, int flags)
|
|
|
-{
|
|
|
- if (!strncmp(option, "ndots:", 6)) {
|
|
|
- const int ndots = strtoint(val);
|
|
|
- if (ndots == -1) return -1;
|
|
|
- if (!(flags & DNS_OPTION_SEARCH)) return 0;
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Setting ndots to %d", ndots);
|
|
|
- if (!global_search_state) global_search_state = search_state_new();
|
|
|
- if (!global_search_state) return -1;
|
|
|
- global_search_state->ndots = ndots;
|
|
|
- } else if (!strncmp(option, "timeout:", 8)) {
|
|
|
- const int timeout = strtoint(val);
|
|
|
- if (timeout == -1) return -1;
|
|
|
- if (!(flags & DNS_OPTION_MISC)) return 0;
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Setting timeout to %d", timeout);
|
|
|
- global_timeout.tv_sec = timeout;
|
|
|
- } else if (!strncmp(option, "max-timeouts:", 12)) {
|
|
|
- const int maxtimeout = strtoint_clipped(val, 1, 255);
|
|
|
- if (maxtimeout == -1) return -1;
|
|
|
- if (!(flags & DNS_OPTION_MISC)) return 0;
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Setting maximum allowed timeouts to %d",
|
|
|
- maxtimeout);
|
|
|
- global_max_nameserver_timeout = maxtimeout;
|
|
|
- } else if (!strncmp(option, "max-inflight:", 13)) {
|
|
|
- const int maxinflight = strtoint_clipped(val, 1, 65000);
|
|
|
- if (maxinflight == -1) return -1;
|
|
|
- if (!(flags & DNS_OPTION_MISC)) return 0;
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Setting maximum inflight requests to %d",
|
|
|
- maxinflight);
|
|
|
- global_max_requests_inflight = maxinflight;
|
|
|
- } else if (!strncmp(option, "attempts:", 9)) {
|
|
|
- int retries = strtoint(val);
|
|
|
- if (retries == -1) return -1;
|
|
|
- if (retries > 255) retries = 255;
|
|
|
- if (!(flags & DNS_OPTION_MISC)) return 0;
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Setting retries to %d", retries);
|
|
|
- global_max_retransmits = retries;
|
|
|
- } else if (!strncmp(option, "randomize-case:", 15)) {
|
|
|
- int randcase = strtoint(val);
|
|
|
- if (!(flags & DNS_OPTION_MISC)) return 0;
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Setting randomize_case to %d", randcase);
|
|
|
- global_randomize_case = randcase;
|
|
|
- }
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-static void
|
|
|
-resolv_conf_parse_line(char *const start, int flags) {
|
|
|
- char *strtok_state;
|
|
|
- static const char *const delims = " \t";
|
|
|
-#define NEXT_TOKEN tor_strtok_r(NULL, delims, &strtok_state)
|
|
|
-
|
|
|
- char *const first_token = tor_strtok_r(start, delims, &strtok_state);
|
|
|
- if (!first_token) return;
|
|
|
-
|
|
|
- if (!strcmp(first_token, "nameserver") && (flags & DNS_OPTION_NAMESERVERS)) {
|
|
|
- const char *const nameserver = NEXT_TOKEN;
|
|
|
- if (nameserver)
|
|
|
- evdns_nameserver_ip_add(nameserver);
|
|
|
- } else if (!strcmp(first_token, "domain") && (flags & DNS_OPTION_SEARCH)) {
|
|
|
- const char *const domain = NEXT_TOKEN;
|
|
|
- if (domain) {
|
|
|
- search_postfix_clear();
|
|
|
- search_postfix_add(domain);
|
|
|
- }
|
|
|
- } else if (!strcmp(first_token, "search") && (flags & DNS_OPTION_SEARCH)) {
|
|
|
- const char *domain;
|
|
|
- search_postfix_clear();
|
|
|
-
|
|
|
- while ((domain = NEXT_TOKEN)) {
|
|
|
- search_postfix_add(domain);
|
|
|
- }
|
|
|
- search_reverse();
|
|
|
- } else if (!strcmp(first_token, "options")) {
|
|
|
- const char *option;
|
|
|
- while ((option = NEXT_TOKEN)) {
|
|
|
- const char *val = strchr(option, ':');
|
|
|
- evdns_set_option(option, val ? val+1 : "", flags);
|
|
|
- }
|
|
|
- }
|
|
|
-#undef NEXT_TOKEN
|
|
|
-}
|
|
|
-
|
|
|
-/* exported function */
|
|
|
-/* returns: */
|
|
|
-/* 0 no errors */
|
|
|
-/* 1 failed to open file */
|
|
|
-/* 2 failed to stat file */
|
|
|
-/* 3 file too large */
|
|
|
-/* 4 out of memory */
|
|
|
-/* 5 short read from file */
|
|
|
-int
|
|
|
-evdns_resolv_conf_parse(int flags, const char *const filename) {
|
|
|
- struct stat st;
|
|
|
- int fd, n, r;
|
|
|
- u8 *resolv;
|
|
|
- char *start;
|
|
|
- int err = 0;
|
|
|
-
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Parsing resolv.conf file %s", filename);
|
|
|
-
|
|
|
- fd = tor_open_cloexec(filename, O_RDONLY, 0);
|
|
|
- if (fd < 0) {
|
|
|
- evdns_resolv_set_defaults(flags);
|
|
|
- return 1;
|
|
|
- }
|
|
|
-
|
|
|
- if (fstat(fd, &st)) { err = 2; goto out1; }
|
|
|
- if (!st.st_size) {
|
|
|
- evdns_resolv_set_defaults(flags);
|
|
|
- err = (flags & DNS_OPTION_NAMESERVERS) ? 6 : 0;
|
|
|
- goto out1;
|
|
|
- }
|
|
|
- if (st.st_size > 65535) { err = 3; goto out1; } /* no resolv.conf should be any bigger */
|
|
|
-
|
|
|
- resolv = (u8 *) mm_malloc((size_t)st.st_size + 1);
|
|
|
- if (!resolv) { err = 4; goto out1; }
|
|
|
-
|
|
|
- n = 0;
|
|
|
- while ((r = (int)read(fd, resolv+n, (size_t)st.st_size-n)) > 0) {
|
|
|
- n += r;
|
|
|
- if (n == st.st_size)
|
|
|
- break;
|
|
|
- assert(n < st.st_size);
|
|
|
- }
|
|
|
- if (r < 0) { err = 5; goto out2; }
|
|
|
- resolv[n] = 0; /* we malloced an extra byte; this should be fine. */
|
|
|
-
|
|
|
- start = (char *) resolv;
|
|
|
- for (;;) {
|
|
|
- char *const newline = strchr(start, '\n');
|
|
|
- if (!newline) {
|
|
|
- resolv_conf_parse_line(start, flags);
|
|
|
- break;
|
|
|
- } else {
|
|
|
- *newline = 0;
|
|
|
- resolv_conf_parse_line(start, flags);
|
|
|
- start = newline + 1;
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- if (!server_head && (flags & DNS_OPTION_NAMESERVERS)) {
|
|
|
- /* no nameservers were configured. */
|
|
|
- evdns_nameserver_ip_add("127.0.0.1");
|
|
|
- err = 6;
|
|
|
- }
|
|
|
- if (flags & DNS_OPTION_SEARCH && (!global_search_state || global_search_state->num_domains == 0)) {
|
|
|
- search_set_from_hostname();
|
|
|
- }
|
|
|
-
|
|
|
-out2:
|
|
|
- mm_free(resolv);
|
|
|
-out1:
|
|
|
- close(fd);
|
|
|
- return err;
|
|
|
-}
|
|
|
-
|
|
|
-#ifdef _WIN32
|
|
|
-/* Add multiple nameservers from a space-or-comma-separated list. */
|
|
|
-static int
|
|
|
-evdns_nameserver_ip_add_line(const char *ips) {
|
|
|
- const char *addr;
|
|
|
- char *buf;
|
|
|
- int r;
|
|
|
- while (*ips) {
|
|
|
- while (ISSPACE(*ips) || *ips == ',' || *ips == '\t')
|
|
|
- ++ips;
|
|
|
- addr = ips;
|
|
|
- while (ISDIGIT(*ips) || *ips == '.' || *ips == ':' || *ips == '[' || *ips == ']')
|
|
|
- ++ips;
|
|
|
- buf = mm_malloc(ips-addr+1);
|
|
|
- if (!buf) return 4;
|
|
|
- memcpy(buf, addr, ips-addr);
|
|
|
- buf[ips-addr] = '\0';
|
|
|
- r = evdns_nameserver_ip_add(buf);
|
|
|
- mm_free(buf);
|
|
|
- if (r) return r;
|
|
|
- }
|
|
|
- return 0;
|
|
|
-}
|
|
|
-
|
|
|
-typedef DWORD(WINAPI *GetNetworkParams_fn_t)(FIXED_INFO *, DWORD*);
|
|
|
-
|
|
|
-/* Use the windows GetNetworkParams interface in iphlpapi.dll to */
|
|
|
-/* figure out what our nameservers are. */
|
|
|
-static int
|
|
|
-load_nameservers_with_getnetworkparams(void)
|
|
|
-{
|
|
|
- /* Based on MSDN examples and inspection of c-ares code. */
|
|
|
- FIXED_INFO *fixed;
|
|
|
- HMODULE handle = 0;
|
|
|
- ULONG size = sizeof(FIXED_INFO);
|
|
|
- void *buf = NULL;
|
|
|
- int status = 0, r, added_any;
|
|
|
- IP_ADDR_STRING *ns;
|
|
|
- GetNetworkParams_fn_t fn;
|
|
|
-
|
|
|
- if (!(handle = load_windows_system_library(TEXT("iphlpapi.dll")))) {
|
|
|
- evdns_log(EVDNS_LOG_WARN, "Could not open iphlpapi.dll");
|
|
|
- /* right now status = 0, doesn't that mean "good" - mikec */
|
|
|
- status = -1;
|
|
|
- goto done;
|
|
|
- }
|
|
|
- if (!(fn = (GetNetworkParams_fn_t) GetProcAddress(handle, TEXT("GetNetworkParams")))) {
|
|
|
- evdns_log(EVDNS_LOG_WARN, "Could not get address of function.");
|
|
|
- /* same as above */
|
|
|
- status = -1;
|
|
|
- goto done;
|
|
|
- }
|
|
|
-
|
|
|
- buf = mm_malloc(size);
|
|
|
- if (!buf) { status = 4; goto done; }
|
|
|
- fixed = buf;
|
|
|
- r = fn(fixed, &size);
|
|
|
- if (r != ERROR_SUCCESS && r != ERROR_BUFFER_OVERFLOW) {
|
|
|
- status = -1;
|
|
|
- goto done;
|
|
|
- }
|
|
|
- if (r != ERROR_SUCCESS) {
|
|
|
- mm_free(buf);
|
|
|
- buf = mm_malloc(size);
|
|
|
- if (!buf) { status = 4; goto done; }
|
|
|
- fixed = buf;
|
|
|
- r = fn(fixed, &size);
|
|
|
- if (r != ERROR_SUCCESS) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "fn() failed.");
|
|
|
- status = -1;
|
|
|
- goto done;
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- assert(fixed);
|
|
|
- added_any = 0;
|
|
|
- ns = &(fixed->DnsServerList);
|
|
|
- while (ns) {
|
|
|
- r = evdns_nameserver_ip_add_line(ns->IpAddress.String);
|
|
|
- if (r) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG,"Could not add nameserver %s to list, "
|
|
|
- "error: %d; status: %d",
|
|
|
- (ns->IpAddress.String),(int)GetLastError(), r);
|
|
|
- status = r;
|
|
|
- } else {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG,"Successfully added %s as nameserver",ns->IpAddress.String);
|
|
|
- added_any++;
|
|
|
- }
|
|
|
-
|
|
|
- ns = ns->Next;
|
|
|
- }
|
|
|
-
|
|
|
- if (!added_any) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "No nameservers added.");
|
|
|
- if (status == 0)
|
|
|
- status = -1;
|
|
|
- } else {
|
|
|
- status = 0;
|
|
|
- }
|
|
|
-
|
|
|
- done:
|
|
|
- if (buf)
|
|
|
- mm_free(buf);
|
|
|
- if (handle)
|
|
|
- FreeLibrary(handle);
|
|
|
- return status;
|
|
|
-}
|
|
|
-
|
|
|
-static int
|
|
|
-config_nameserver_from_reg_key(HKEY key, const TCHAR *subkey)
|
|
|
-{
|
|
|
- char *buf;
|
|
|
- char ansibuf[MAX_PATH] = {0};
|
|
|
- DWORD bufsz = 0, type = 0;
|
|
|
- int status = 0;
|
|
|
-
|
|
|
- if (RegQueryValueEx(key, subkey, 0, &type, NULL, &bufsz)
|
|
|
- != ERROR_MORE_DATA)
|
|
|
- return -1;
|
|
|
- if (!(buf = mm_malloc(bufsz)))
|
|
|
- return -1;
|
|
|
-
|
|
|
- if (RegQueryValueEx(key, subkey, 0, &type, (LPBYTE)buf, &bufsz)
|
|
|
- == ERROR_SUCCESS && bufsz > 1) {
|
|
|
- wcstombs(ansibuf,(wchar_t*)buf,MAX_PATH);/*XXXX UNICODE */
|
|
|
- abuf[MAX_PATH-1] = '\0';
|
|
|
- status = evdns_nameserver_ip_add_line(ansibuf);
|
|
|
- }
|
|
|
-
|
|
|
- mm_free(buf);
|
|
|
- return status;
|
|
|
-}
|
|
|
-
|
|
|
-#define SERVICES_KEY TEXT("System\\CurrentControlSet\\Services\\")
|
|
|
-#define WIN_NS_9X_KEY SERVICES_KEY TEXT("VxD\\MSTCP")
|
|
|
-#define WIN_NS_NT_KEY SERVICES_KEY TEXT("Tcpip\\Parameters")
|
|
|
-
|
|
|
-static int
|
|
|
-load_nameservers_from_registry(void)
|
|
|
-{
|
|
|
- int found = 0;
|
|
|
- int r;
|
|
|
- OSVERSIONINFO info;
|
|
|
- memset(&info, 0, sizeof(info));
|
|
|
- info.dwOSVersionInfoSize = sizeof (info);
|
|
|
- GetVersionEx(&info);
|
|
|
-
|
|
|
-#define TRY(k, name) \
|
|
|
- if (!found && config_nameserver_from_reg_key(k,TEXT(name)) == 0) { \
|
|
|
- evdns_log(EVDNS_LOG_DEBUG,"Found nameservers in %s/%s",#k,name); \
|
|
|
- found = 1; \
|
|
|
- } else if (!found) { \
|
|
|
- evdns_log(EVDNS_LOG_DEBUG,"Didn't find nameservers in %s/%s", \
|
|
|
- #k,#name); \
|
|
|
- }
|
|
|
-
|
|
|
- if (info.dwMajorVersion >= 5) { /* NT */
|
|
|
- HKEY nt_key = 0, interfaces_key = 0;
|
|
|
-
|
|
|
- if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, WIN_NS_NT_KEY, 0,
|
|
|
- KEY_READ, &nt_key) != ERROR_SUCCESS) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG,"Couldn't open nt key, %d",(int)GetLastError());
|
|
|
- return -1;
|
|
|
- }
|
|
|
- r = RegOpenKeyEx(nt_key, TEXT("Interfaces"), 0,
|
|
|
- KEY_QUERY_VALUE|KEY_ENUMERATE_SUB_KEYS,
|
|
|
- &interfaces_key);
|
|
|
- if (r != ERROR_SUCCESS) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG,"Couldn't open interfaces key, %d",(int)GetLastError());
|
|
|
- return -1;
|
|
|
- }
|
|
|
- TRY(nt_key, "NameServer");
|
|
|
- TRY(nt_key, "DhcpNameServer");
|
|
|
- TRY(interfaces_key, "NameServer");
|
|
|
- TRY(interfaces_key, "DhcpNameServer");
|
|
|
- RegCloseKey(interfaces_key);
|
|
|
- RegCloseKey(nt_key);
|
|
|
- } else {
|
|
|
- HKEY win_key = 0;
|
|
|
- if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, WIN_NS_9X_KEY, 0,
|
|
|
- KEY_READ, &win_key) != ERROR_SUCCESS) {
|
|
|
- evdns_log(EVDNS_LOG_DEBUG, "Couldn't open registry key, %d", (int)GetLastError());
|
|
|
- return -1;
|
|
|
- }
|
|
|
- TRY(win_key, "NameServer");
|
|
|
- RegCloseKey(win_key);
|
|
|
- }
|
|
|
-
|
|
|
- if (found == 0) {
|
|
|
- evdns_log(EVDNS_LOG_WARN,"Didn't find any nameservers.");
|
|
|
- }
|
|
|
-
|
|
|
- return found ? 0 : -1;
|
|
|
-#undef TRY
|
|
|
-}
|
|
|
-
|
|
|
-int
|
|
|
-evdns_config_windows_nameservers(void)
|
|
|
-{
|
|
|
- if (load_nameservers_with_getnetworkparams() == 0)
|
|
|
- return 0;
|
|
|
- return load_nameservers_from_registry();
|
|
|
-}
|
|
|
-#endif
|
|
|
-
|
|
|
-int
|
|
|
-evdns_init(void)
|
|
|
-{
|
|
|
- int res = 0;
|
|
|
-#ifdef _WIN32
|
|
|
- evdns_config_windows_nameservers();
|
|
|
-#else
|
|
|
- res = evdns_resolv_conf_parse(DNS_OPTIONS_ALL, "/etc/resolv.conf");
|
|
|
-#endif
|
|
|
-
|
|
|
- return (res);
|
|
|
-}
|
|
|
-
|
|
|
-const char *
|
|
|
-evdns_err_to_string(int err)
|
|
|
-{
|
|
|
- switch (err) {
|
|
|
- case DNS_ERR_NONE: return "no error";
|
|
|
- case DNS_ERR_FORMAT: return "misformatted query";
|
|
|
- case DNS_ERR_SERVERFAILED: return "server failed";
|
|
|
- case DNS_ERR_NOTEXIST: return "name does not exist";
|
|
|
- case DNS_ERR_NOTIMPL: return "query not implemented";
|
|
|
- case DNS_ERR_REFUSED: return "refused";
|
|
|
-
|
|
|
- case DNS_ERR_TRUNCATED: return "reply truncated or ill-formed";
|
|
|
- case DNS_ERR_UNKNOWN: return "unknown";
|
|
|
- case DNS_ERR_TIMEOUT: return "request timed out";
|
|
|
- case DNS_ERR_SHUTDOWN: return "dns subsystem shut down";
|
|
|
- default: return "[Unknown error code]";
|
|
|
- }
|
|
|
-}
|
|
|
-
|
|
|
-void
|
|
|
-evdns_shutdown(int fail_requests)
|
|
|
-{
|
|
|
- struct nameserver *server, *server_next;
|
|
|
- struct search_domain *dom, *dom_next;
|
|
|
-
|
|
|
- while (req_head) {
|
|
|
- if (fail_requests)
|
|
|
- reply_callback(req_head, 0, DNS_ERR_SHUTDOWN, NULL);
|
|
|
- request_finished(req_head, &req_head);
|
|
|
- }
|
|
|
- while (req_waiting_head) {
|
|
|
- if (fail_requests)
|
|
|
- reply_callback(req_waiting_head, 0, DNS_ERR_SHUTDOWN, NULL);
|
|
|
- request_finished(req_waiting_head, &req_waiting_head);
|
|
|
- }
|
|
|
- global_requests_inflight = global_requests_waiting = 0;
|
|
|
-
|
|
|
- for (server = server_head; server; server = server_next) {
|
|
|
- server_next = server->next;
|
|
|
- if (server->socket >= 0)
|
|
|
- CLOSE_SOCKET(server->socket);
|
|
|
- (void) event_del(&server->event);
|
|
|
- del_timeout_event(server);
|
|
|
- CLEAR(server);
|
|
|
- mm_free(server);
|
|
|
- if (server_next == server_head)
|
|
|
- break;
|
|
|
- }
|
|
|
- server_head = NULL;
|
|
|
- global_good_nameservers = 0;
|
|
|
-
|
|
|
- if (global_search_state) {
|
|
|
- for (dom = global_search_state->head; dom; dom = dom_next) {
|
|
|
- dom_next = dom->next;
|
|
|
- CLEAR(dom);
|
|
|
- mm_free(dom);
|
|
|
- }
|
|
|
- CLEAR(global_search_state);
|
|
|
- mm_free(global_search_state);
|
|
|
- global_search_state = NULL;
|
|
|
- }
|
|
|
- evdns_log_fn = NULL;
|
|
|
-}
|
|
|
-
|
|
|
-#ifdef EVDNS_MAIN
|
|
|
-void
|
|
|
-main_callback(int result, char type, int count, int ttl,
|
|
|
- void *addrs, void *orig) {
|
|
|
- char *n = (char*)orig;
|
|
|
- int i;
|
|
|
- for (i = 0; i < count; ++i) {
|
|
|
- if (type == DNS_IPv4_A) {
|
|
|
- printf("%s: %s\n", n, debug_ntoa(((u32*)addrs)[i]));
|
|
|
- } else if (type == DNS_PTR) {
|
|
|
- printf("%s: %s\n", n, ((char**)addrs)[i]);
|
|
|
- }
|
|
|
- }
|
|
|
- if (!count) {
|
|
|
- printf("%s: No answer (%d)\n", n, result);
|
|
|
- }
|
|
|
- fflush(stdout);
|
|
|
-}
|
|
|
-void
|
|
|
-evdns_server_callback(struct evdns_server_request *req, void *data)
|
|
|
-{
|
|
|
- int i, r;
|
|
|
- (void)data;
|
|
|
- /* dummy; give 192.168.11.11 as an answer for all A questions,
|
|
|
- * give foo.bar.example.com as an answer for all PTR questions. */
|
|
|
- for (i = 0; i < req->nquestions; ++i) {
|
|
|
- u32 ans = htonl(0xc0a80b0bUL);
|
|
|
- if (req->questions[i]->type == EVDNS_TYPE_A &&
|
|
|
- req->questions[i]->dns_question_class == EVDNS_CLASS_INET) {
|
|
|
- printf(" -- replying for %s (A)\n", req->questions[i]->name);
|
|
|
- r = evdns_server_request_add_a_reply(req, req->questions[i]->name,
|
|
|
- 1, &ans, 10);
|
|
|
- if (r<0)
|
|
|
- printf("eeep, didn't work.\n");
|
|
|
- } else if (req->questions[i]->type == EVDNS_TYPE_PTR &&
|
|
|
- req->questions[i]->dns_question_class == EVDNS_CLASS_INET) {
|
|
|
- printf(" -- replying for %s (PTR)\n", req->questions[i]->name);
|
|
|
- r = evdns_server_request_add_ptr_reply(req, NULL, req->questions[i]->name,
|
|
|
- "foo.bar.example.com", 10);
|
|
|
- } else {
|
|
|
- printf(" -- skipping %s [%d %d]\n", req->questions[i]->name,
|
|
|
- req->questions[i]->type, req->questions[i]->dns_question_class);
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- r = evdns_server_request_respond(req, 0);
|
|
|
- if (r<0)
|
|
|
- printf("eeek, couldn't send reply.\n");
|
|
|
-}
|
|
|
-
|
|
|
-void
|
|
|
-logfn(int is_warn, const char *msg) {
|
|
|
- (void) is_warn;
|
|
|
- fprintf(stderr, "%s\n", msg);
|
|
|
-}
|
|
|
-int
|
|
|
-main(int c, char **v) {
|
|
|
- int idx;
|
|
|
- int reverse = 0, verbose = 1, servertest = 0;
|
|
|
- if (c<2) {
|
|
|
- fprintf(stderr, "syntax: %s [-x] [-v] hostname\n", v[0]);
|
|
|
- fprintf(stderr, "syntax: %s [-servertest]\n", v[0]);
|
|
|
- return 1;
|
|
|
- }
|
|
|
- idx = 1;
|
|
|
- while (idx < c && v[idx][0] == '-') {
|
|
|
- if (!strcmp(v[idx], "-x"))
|
|
|
- reverse = 1;
|
|
|
- else if (!strcmp(v[idx], "-v"))
|
|
|
- verbose = 1;
|
|
|
- else if (!strcmp(v[idx], "-servertest"))
|
|
|
- servertest = 1;
|
|
|
- else
|
|
|
- fprintf(stderr, "Unknown option %s\n", v[idx]);
|
|
|
- ++idx;
|
|
|
- }
|
|
|
- event_init();
|
|
|
- if (verbose)
|
|
|
- evdns_set_log_fn(logfn);
|
|
|
- evdns_resolv_conf_parse(DNS_OPTION_NAMESERVERS, "/etc/resolv.conf");
|
|
|
- if (servertest) {
|
|
|
- int sock;
|
|
|
- struct sockaddr_in my_addr;
|
|
|
-#if 1
|
|
|
- sock = tor_open_socket_nonblocking(PF_INET, SOCK_DGRAM, 0)
|
|
|
-#else
|
|
|
- sock = tor_open_socket(PF_INET, SOCK_DGRAM, 0);
|
|
|
- fcntl(sock, F_SETFL, O_NONBLOCK);
|
|
|
-#endif
|
|
|
- my_addr.sin_family = AF_INET;
|
|
|
- my_addr.sin_port = htons(10053);
|
|
|
- my_addr.sin_addr.s_addr = INADDR_ANY;
|
|
|
- if (bind(sock, (struct sockaddr*)&my_addr, sizeof(my_addr))<0) {
|
|
|
- perror("bind");
|
|
|
- exit(1);
|
|
|
- }
|
|
|
- evdns_add_server_port(sock, 0, evdns_server_callback, NULL);
|
|
|
- }
|
|
|
- for (; idx < c; ++idx) {
|
|
|
- if (reverse) {
|
|
|
- struct in_addr addr;
|
|
|
- if (!inet_aton(v[idx], &addr)) {
|
|
|
- fprintf(stderr, "Skipping non-IP %s\n", v[idx]);
|
|
|
- continue;
|
|
|
- }
|
|
|
- fprintf(stderr, "resolving %s...\n",v[idx]);
|
|
|
- evdns_resolve_reverse(&addr, 0, main_callback, v[idx]);
|
|
|
- } else {
|
|
|
- fprintf(stderr, "resolving (fwd) %s...\n",v[idx]);
|
|
|
- evdns_resolve_ipv4(v[idx], 0, main_callback, v[idx]);
|
|
|
- }
|
|
|
- }
|
|
|
- fflush(stdout);
|
|
|
- event_dispatch();
|
|
|
- return 0;
|
|
|
-}
|
|
|
-#endif
|
|
|
-
|
|
|
-/* Local Variables: */
|
|
|
-/* tab-width: 4 */
|
|
|
-/* c-basic-offset: 4 */
|
|
|
-/* indent-tabs-mode: t */
|
|
|
-/* End: */
|
|
|
-
|
Nick Mathewson