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- /* Copyright (c) 2003-2004, Roger Dingledine
- * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
- * Copyright (c) 2007-2018, The Tor Project, Inc. */
- /* See LICENSE for licensing information */
- #include "lib/net/resolve.h"
- #include "lib/net/address.h"
- #include "lib/malloc/util_malloc.h"
- #include "siphash.h"
- #include "ht.h"
- #ifdef HAVE_SYS_TYPES_H
- #include <sys/types.h>
- #endif
- #ifdef HAVE_SYS_SOCKET_H
- #include <sys/socket.h>
- #endif
- #ifdef HAVE_NETDB_H
- #include <netdb.h>
- #endif
- #include <string.h>
- /** Similar behavior to Unix gethostbyname: resolve <b>name</b>, and set
- * *<b>addr</b> to the proper IP address, in host byte order. Returns 0
- * on success, -1 on failure; 1 on transient failure.
- *
- * (This function exists because standard windows gethostbyname
- * doesn't treat raw IP addresses properly.)
- */
- MOCK_IMPL(int,
- tor_lookup_hostname,(const char *name, uint32_t *addr))
- {
- tor_addr_t myaddr;
- int ret;
- if ((ret = tor_addr_lookup(name, AF_INET, &myaddr)))
- return ret;
- if (tor_addr_family(&myaddr) == AF_INET) {
- *addr = tor_addr_to_ipv4h(&myaddr);
- return ret;
- }
- return -1;
- }
- #ifdef USE_SANDBOX_GETADDRINFO
- /** True if we should only return cached values */
- static int sandbox_getaddrinfo_is_active = 0;
- /** Cache entry for getaddrinfo results; used when sandboxing is implemented
- * so that we can consult the cache when the sandbox prevents us from doing
- * getaddrinfo.
- *
- * We support only a limited range of getaddrinfo calls, where servname is null
- * and hints contains only socktype=SOCK_STREAM, family in INET,INET6,UNSPEC.
- */
- typedef struct cached_getaddrinfo_item_t {
- HT_ENTRY(cached_getaddrinfo_item_t) node;
- char *name;
- int family;
- /** set if no error; otherwise NULL */
- struct addrinfo *res;
- /** 0 for no error; otherwise an EAI_* value */
- int err;
- } cached_getaddrinfo_item_t;
- static unsigned
- cached_getaddrinfo_item_hash(const cached_getaddrinfo_item_t *item)
- {
- return (unsigned)siphash24g(item->name, strlen(item->name)) + item->family;
- }
- static unsigned
- cached_getaddrinfo_items_eq(const cached_getaddrinfo_item_t *a,
- const cached_getaddrinfo_item_t *b)
- {
- return (a->family == b->family) && 0 == strcmp(a->name, b->name);
- }
- #define cached_getaddrinfo_item_free(item) \
- FREE_AND_NULL(cached_getaddrinfo_item_t, \
- cached_getaddrinfo_item_free_, (item))
- static void
- cached_getaddrinfo_item_free_(cached_getaddrinfo_item_t *item)
- {
- if (item == NULL)
- return;
- tor_free(item->name);
- if (item->res)
- freeaddrinfo(item->res);
- tor_free(item);
- }
- static HT_HEAD(getaddrinfo_cache, cached_getaddrinfo_item_t)
- getaddrinfo_cache = HT_INITIALIZER();
- HT_PROTOTYPE(getaddrinfo_cache, cached_getaddrinfo_item_t, node,
- cached_getaddrinfo_item_hash,
- cached_getaddrinfo_items_eq)
- HT_GENERATE2(getaddrinfo_cache, cached_getaddrinfo_item_t, node,
- cached_getaddrinfo_item_hash,
- cached_getaddrinfo_items_eq,
- 0.6, tor_reallocarray_, tor_free_)
- /** If true, don't try to cache getaddrinfo results. */
- static int sandbox_getaddrinfo_cache_disabled = 0;
- /** Tell the sandbox layer not to try to cache getaddrinfo results. Used as in
- * tor-resolve, when we have no intention of initializing crypto or of
- * installing the sandbox.*/
- void
- sandbox_disable_getaddrinfo_cache(void)
- {
- sandbox_getaddrinfo_cache_disabled = 1;
- }
- void
- sandbox_freeaddrinfo(struct addrinfo *ai)
- {
- if (sandbox_getaddrinfo_cache_disabled)
- freeaddrinfo(ai);
- }
- int
- sandbox_getaddrinfo(const char *name, const char *servname,
- const struct addrinfo *hints,
- struct addrinfo **res)
- {
- int err;
- struct cached_getaddrinfo_item_t search, *item;
- if (sandbox_getaddrinfo_cache_disabled) {
- return getaddrinfo(name, NULL, hints, res);
- }
- if (servname != NULL) {
- log_warn(LD_BUG, "called with non-NULL servname");
- return EAI_NONAME;
- }
- if (name == NULL) {
- log_warn(LD_BUG, "called with NULL name");
- return EAI_NONAME;
- }
- *res = NULL;
- memset(&search, 0, sizeof(search));
- search.name = (char *) name;
- search.family = hints ? hints->ai_family : AF_UNSPEC;
- item = HT_FIND(getaddrinfo_cache, &getaddrinfo_cache, &search);
- if (! sandbox_getaddrinfo_is_active) {
- /* If the sandbox is not turned on yet, then getaddrinfo and store the
- result. */
- err = getaddrinfo(name, NULL, hints, res);
- log_info(LD_NET,"(Sandbox) getaddrinfo %s.", err ? "failed" : "succeeded");
- if (! item) {
- item = tor_malloc_zero(sizeof(*item));
- item->name = tor_strdup(name);
- item->family = hints ? hints->ai_family : AF_UNSPEC;
- HT_INSERT(getaddrinfo_cache, &getaddrinfo_cache, item);
- }
- if (item->res) {
- freeaddrinfo(item->res);
- item->res = NULL;
- }
- item->res = *res;
- item->err = err;
- return err;
- }
- /* Otherwise, the sandbox is on. If we have an item, yield its cached
- result. */
- if (item) {
- *res = item->res;
- return item->err;
- }
- /* getting here means something went wrong */
- log_err(LD_BUG,"(Sandbox) failed to get address %s!", name);
- return EAI_NONAME;
- }
- int
- sandbox_add_addrinfo(const char *name)
- {
- struct addrinfo *res;
- struct addrinfo hints;
- int i;
- static const int families[] = { AF_INET, AF_INET6, AF_UNSPEC };
- memset(&hints, 0, sizeof(hints));
- hints.ai_socktype = SOCK_STREAM;
- for (i = 0; i < 3; ++i) {
- hints.ai_family = families[i];
- res = NULL;
- (void) sandbox_getaddrinfo(name, NULL, &hints, &res);
- if (res)
- sandbox_freeaddrinfo(res);
- }
- return 0;
- }
- void
- sandbox_free_getaddrinfo_cache(void)
- {
- cached_getaddrinfo_item_t **next, **item, *this;
- for (item = HT_START(getaddrinfo_cache, &getaddrinfo_cache);
- item;
- item = next) {
- this = *item;
- next = HT_NEXT_RMV(getaddrinfo_cache, &getaddrinfo_cache, item);
- cached_getaddrinfo_item_free(this);
- }
- HT_CLEAR(getaddrinfo_cache, &getaddrinfo_cache);
- }
- void
- sandbox_make_getaddrinfo_cache_active(void)
- {
- sandbox_getaddrinfo_is_active = 1;
- }
- #endif
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