projects / solanum.git / blame
| Commit | Line | Data |
|---|---|---|
| 524a5b3a JT |
1 | /* |
| 2 | * charybdis: A slightly useful ircd. | |
| 3 | * ipv4_from_ipv6.c: Finds IPv4 addresses behind IPv6 transition technologies | |
| 4 | * | |
| 5 | * Copyright (C) 2012 Jilles Tjoelker | |
| 6 | * | |
| 7 | * Redistribution and use in source and binary forms, with or without | |
| 8 | * modification, are permitted provided that the following conditions are | |
| 9 | * met: | |
| 10 | * | |
| 11 | * 1. Redistributions of source code must retain the above copyright notice, | |
| 12 | * this list of conditions and the following disclaimer. | |
| 13 | * | |
| 14 | * 2. Redistributions in binary form must reproduce the above copyright | |
| 15 | * notice, this list of conditions and the following disclaimer in the | |
| 16 | * documentation and/or other materials provided with the distribution. | |
| 17 | * | |
| 18 | * 3. The name of the author may not be used to endorse or promote products | |
| 19 | * derived from this software without specific prior written permission. | |
| 20 | * | |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
| 22 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED | |
| 23 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
| 24 | * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, | |
| 25 | * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES | |
| 26 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR | |
| 27 | * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
| 29 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING | |
| 30 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
| 31 | * POSSIBILITY OF SUCH DAMAGE. | |
| 32 | * | |
| 33 | */ | |
| 34 | ||
| 35 | #include "stdinc.h" | |
| 36 | #include "ipv4_from_ipv6.h" | |
| 37 | ||
| 38 | #ifdef RB_IPV6 | |
| 39 | int | |
| 40 | ipv4_from_ipv6(const struct sockaddr_in6 *restrict ip6, | |
| 41 | struct sockaddr_in *restrict ip4) | |
| 42 | { | |
| 43 | int i; | |
| 44 | ||
| 45 | if (!memcmp(ip6->sin6_addr.s6_addr, "\x20\x02", 2)) | |
| 46 | { | |
| 47 | /* 6to4 and similar */ | |
| 48 | memcpy(&ip4->sin_addr, ip6->sin6_addr.s6_addr + 2, 4); | |
| 49 | } | |
| 50 | else if (!memcmp(ip6->sin6_addr.s6_addr, "\x20\x01\x00\x00", 4)) | |
| 51 | { | |
| 52 | /* Teredo */ | |
| 53 | for (i = 0; i < 4; i++) | |
| 54 | ((uint8_t *)&ip4->sin_addr)[i] = 0xFF ^ | |
| 55 | ip6->sin6_addr.s6_addr[12 + i]; | |
| 56 | } | |
| 57 | else | |
| 58 | return 0; | |
| 59 | SET_SS_LEN(ip4, sizeof(struct sockaddr_in)); | |
| 60 | ip4->sin_family = AF_INET; | |
| 61 | ip4->sin_port = 0; | |
| 62 | return 1; | |
| 63 | } | |
| 64 | #endif /* RB_IPV6 */ |