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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/ipv6.h"
- #include "lib/net/ipv4.h"
- #include "lib/string/util_string.h"
- #include "lib/string/compat_string.h"
- #include "lib/string/compat_ctype.h"
- #include "lib/string/printf.h"
- #include "lib/string/scanf.h"
- #include "lib/log/util_bug.h"
- #ifdef HAVE_ARPA_INET_H
- #include <arpa/inet.h>
- #endif
- #include <stdlib.h>
- #include <string.h>
- /** Given <b>af</b>==AF_INET and <b>src</b> a struct in_addr, or
- * <b>af</b>==AF_INET6 and <b>src</b> a struct in6_addr, try to format the
- * address and store it in the <b>len</b>-byte buffer <b>dst</b>. Returns
- * <b>dst</b> on success, NULL on failure.
- *
- * (Like inet_ntop(af,src,dst,len), but works on platforms that don't have it:
- * Tor sometimes needs to format ipv6 addresses even on platforms without ipv6
- * support.) */
- const char *
- tor_inet_ntop(int af, const void *src, char *dst, size_t len)
- {
- if (af == AF_INET) {
- if (tor_inet_ntoa(src, dst, len) < 0)
- return NULL;
- else
- return dst;
- } else if (af == AF_INET6) {
- const struct in6_addr *addr = src;
- char buf[64], *cp;
- int longestGapLen = 0, longestGapPos = -1, i,
- curGapPos = -1, curGapLen = 0;
- uint16_t words[8];
- for (i = 0; i < 8; ++i) {
- words[i] = (((uint16_t)addr->s6_addr[2*i])<<8) + addr->s6_addr[2*i+1];
- }
- if (words[0] == 0 && words[1] == 0 && words[2] == 0 && words[3] == 0 &&
- words[4] == 0 && ((words[5] == 0 && words[6] && words[7]) ||
- (words[5] == 0xffff))) {
- /* This is an IPv4 address. */
- if (words[5] == 0) {
- tor_snprintf(buf, sizeof(buf), "::%d.%d.%d.%d",
- addr->s6_addr[12], addr->s6_addr[13],
- addr->s6_addr[14], addr->s6_addr[15]);
- } else {
- tor_snprintf(buf, sizeof(buf), "::%x:%d.%d.%d.%d", words[5],
- addr->s6_addr[12], addr->s6_addr[13],
- addr->s6_addr[14], addr->s6_addr[15]);
- }
- if ((strlen(buf) + 1) > len) /* +1 for \0 */
- return NULL;
- strlcpy(dst, buf, len);
- return dst;
- }
- i = 0;
- while (i < 8) {
- if (words[i] == 0) {
- curGapPos = i++;
- curGapLen = 1;
- while (i<8 && words[i] == 0) {
- ++i; ++curGapLen;
- }
- if (curGapLen > longestGapLen) {
- longestGapPos = curGapPos;
- longestGapLen = curGapLen;
- }
- } else {
- ++i;
- }
- }
- if (longestGapLen<=1)
- longestGapPos = -1;
- cp = buf;
- for (i = 0; i < 8; ++i) {
- if (words[i] == 0 && longestGapPos == i) {
- if (i == 0)
- *cp++ = ':';
- *cp++ = ':';
- while (i < 8 && words[i] == 0)
- ++i;
- --i; /* to compensate for loop increment. */
- } else {
- tor_snprintf(cp, sizeof(buf)-(cp-buf), "%x", (unsigned)words[i]);
- cp += strlen(cp);
- if (i != 7)
- *cp++ = ':';
- }
- }
- *cp = '\0';
- if ((strlen(buf) + 1) > len) /* +1 for \0 */
- return NULL;
- strlcpy(dst, buf, len);
- return dst;
- } else {
- return NULL;
- }
- }
- /** Given <b>af</b>==AF_INET or <b>af</b>==AF_INET6, and a string <b>src</b>
- * encoding an IPv4 address or IPv6 address correspondingly, try to parse the
- * address and store the result in <b>dst</b> (which must have space for a
- * struct in_addr or a struct in6_addr, as appropriate). Return 1 on success,
- * 0 on a bad parse, and -1 on a bad <b>af</b>.
- *
- * (Like inet_pton(af,src,dst) but works on platforms that don't have it: Tor
- * sometimes needs to format ipv6 addresses even on platforms without ipv6
- * support.) */
- int
- tor_inet_pton(int af, const char *src, void *dst)
- {
- if (af == AF_INET) {
- return tor_inet_aton(src, dst);
- } else if (af == AF_INET6) {
- struct in6_addr *out = dst;
- uint16_t words[8];
- int gapPos = -1, i, setWords=0;
- const char *dot = strchr(src, '.');
- const char *eow; /* end of words. */
- memset(words, 0xf8, sizeof(words));
- if (dot == src)
- return 0;
- else if (!dot)
- eow = src+strlen(src);
- else {
- unsigned byte1,byte2,byte3,byte4;
- char more;
- for (eow = dot-1; eow > src && TOR_ISDIGIT(*eow); --eow)
- ;
- if (*eow != ':')
- return 0;
- ++eow;
- /* We use "scanf" because some platform inet_aton()s are too lax
- * about IPv4 addresses of the form "1.2.3" */
- if (tor_sscanf(eow, "%3u.%3u.%3u.%3u%c",
- &byte1,&byte2,&byte3,&byte4,&more) != 4)
- return 0;
- if (byte1 > 255 || byte2 > 255 || byte3 > 255 || byte4 > 255)
- return 0;
- words[6] = (byte1<<8) | byte2;
- words[7] = (byte3<<8) | byte4;
- setWords += 2;
- }
- i = 0;
- while (src < eow) {
- if (i > 7)
- return 0;
- if (TOR_ISXDIGIT(*src)) {
- char *next;
- ssize_t len;
- long r = strtol(src, &next, 16);
- if (next == NULL || next == src) {
- /* The 'next == src' error case can happen on versions of openbsd
- * which treat "0xfoo" as an error, rather than as "0" followed by
- * "xfoo". */
- return 0;
- }
- len = *next == '\0' ? eow - src : next - src;
- if (len > 4)
- return 0;
- if (len > 1 && !TOR_ISXDIGIT(src[1]))
- return 0; /* 0x is not valid */
- tor_assert(r >= 0);
- tor_assert(r < 65536);
- words[i++] = (uint16_t)r;
- setWords++;
- src = next;
- if (*src != ':' && src != eow)
- return 0;
- ++src;
- } else if (*src == ':' && i > 0 && gapPos == -1) {
- gapPos = i;
- ++src;
- } else if (*src == ':' && i == 0 && src+1 < eow && src[1] == ':' &&
- gapPos == -1) {
- gapPos = i;
- src += 2;
- } else {
- return 0;
- }
- }
- if (setWords > 8 ||
- (setWords == 8 && gapPos != -1) ||
- (setWords < 8 && gapPos == -1))
- return 0;
- if (gapPos >= 0) {
- int nToMove = setWords - (dot ? 2 : 0) - gapPos;
- int gapLen = 8 - setWords;
- tor_assert(nToMove >= 0);
- memmove(&words[gapPos+gapLen], &words[gapPos],
- sizeof(uint16_t)*nToMove);
- memset(&words[gapPos], 0, sizeof(uint16_t)*gapLen);
- }
- for (i = 0; i < 8; ++i) {
- out->s6_addr[2*i ] = words[i] >> 8;
- out->s6_addr[2*i+1] = words[i] & 0xff;
- }
- return 1;
- } else {
- return -1;
- }
- }
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