/* $OpenBSD: recvfromto.c,v 1.7 2024/02/26 08:25:51 yasuoka Exp $ */ /* adapted from ipsec-tools 0.6 src/racoon/sockmisc.c */ /* * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the project nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include #include #include #include #include #include "recvfromto.h" /* * Receive packet, with src/dst information. It is assumed that necessary * setsockopt() have already performed on socket. */ int recvfromto_nat_t(int s, void *buf, size_t buflen, int flags, struct sockaddr *from, u_int *fromlen, struct sockaddr *to, u_int *tolen, void *ipsec, u_int *ipseclen) { int otolen; u_int oipseclen = 0; ssize_t len; struct sockaddr_storage ss; struct msghdr m; struct cmsghdr *cm; struct iovec iov[2]; u_char cmsgbuf[256]; struct in6_pktinfo *pi; struct sockaddr_in *sin4; socklen_t sslen; struct sockaddr_in6 *sin6; sslen = sizeof(ss); if (getsockname(s, (struct sockaddr *)&ss, &sslen) < 0) return -1; m.msg_name = (caddr_t)from; m.msg_namelen = *fromlen; iov[0].iov_base = (caddr_t)buf; iov[0].iov_len = buflen; m.msg_iov = iov; m.msg_iovlen = 1; memset(cmsgbuf, 0, sizeof(cmsgbuf)); cm = (struct cmsghdr *)cmsgbuf; m.msg_control = (caddr_t)cm; m.msg_controllen = sizeof(cmsgbuf); if ((len = recvmsg(s, &m, flags)) <= 0) { return len; } *fromlen = m.msg_namelen; if (ipsec && ipseclen) { oipseclen = *ipseclen; *ipseclen = 0; } otolen = *tolen; *tolen = 0; for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&m); m.msg_controllen != 0 && cm; cm = (struct cmsghdr *)CMSG_NXTHDR(&m, cm)) { if (ss.ss_family == AF_INET6 && cm->cmsg_level == IPPROTO_IPV6 && cm->cmsg_type == IPV6_PKTINFO && otolen >= sizeof(*sin6)) { pi = (struct in6_pktinfo *)(CMSG_DATA(cm)); *tolen = sizeof(*sin6); sin6 = (struct sockaddr_in6 *)to; memset(sin6, 0, sizeof(*sin6)); sin6->sin6_family = AF_INET6; #ifndef __linux__ sin6->sin6_len = sizeof(*sin6); #endif memcpy(&sin6->sin6_addr, &pi->ipi6_addr, sizeof(sin6->sin6_addr)); /* XXX other cases, such as site-local? */ if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) sin6->sin6_scope_id = pi->ipi6_ifindex; else sin6->sin6_scope_id = 0; sin6->sin6_port = ((struct sockaddr_in6 *)&ss)->sin6_port; otolen = -1; /* "to" already set */ continue; } #ifdef IP_IPSECFLOWINFO if (ss.ss_family == AF_INET /* ?? */ && cm->cmsg_level == IPPROTO_IP && cm->cmsg_type == IP_IPSECFLOWINFO && oipseclen >= sizeof(u_int32_t)) { *ipseclen = sizeof(u_int32_t); memcpy(ipsec, CMSG_DATA(cm), *ipseclen); continue; } #endif #ifdef __linux__ if (ss.ss_family == AF_INET && cm->cmsg_level == IPPROTO_IP && cm->cmsg_type == IP_PKTINFO && otolen >= sizeof(sin4)) { struct in_pktinfo *pi = (struct in_pktinfo *)(CMSG_DATA(cm)); *tolen = sizeof(*sin4); sin4 = (struct sockaddr_in *)to; memset(sin4, 0, sizeof(*sin4)); sin4->sin_family = AF_INET; memcpy(&sin4->sin_addr, &pi->ipi_addr, sizeof(sin4->sin_addr)); sin4->sin_port = ((struct sockaddr_in *)&ss)->sin_port; otolen = -1; /* "to" already set */ continue; } #endif #ifdef IPV6_RECVDSTADDR if (ss.ss_family == AF_INET6 && cm->cmsg_level == IPPROTO_IPV6 && cm->cmsg_type == IPV6_RECVDSTADDR && otolen >= sizeof(*sin6)) { *tolen = sizeof(*sin6); sin6 = (struct sockaddr_in6 *)to; memset(sin6, 0, sizeof(*sin6)); sin6->sin6_family = AF_INET6; sin6->sin6_len = sizeof(*sin6); memcpy(&sin6->sin6_addr, CMSG_DATA(cm), sizeof(sin6->sin6_addr)); sin6->sin6_port = ((struct sockaddr_in6 *)&ss)->sin6_port; otolen = -1; /* "to" already set */ continue; } #endif #ifndef __linux__ if (ss.ss_family == AF_INET && cm->cmsg_level == IPPROTO_IP && cm->cmsg_type == IP_RECVDSTADDR && otolen >= sizeof(*sin4)) { *tolen = sizeof(*sin4); sin4 = (struct sockaddr_in *)to; memset(sin4, 0, sizeof(*sin4)); sin4->sin_family = AF_INET; sin4->sin_len = sizeof(*sin4); memcpy(&sin4->sin_addr, CMSG_DATA(cm), sizeof(sin4->sin_addr)); sin4->sin_port = ((struct sockaddr_in *)&ss)->sin_port; otolen = -1; /* "to" already set */ continue; } #endif } return len; } int recvfromto(int s, void *buf, size_t buflen, int flags, struct sockaddr *from, u_int *fromlen, struct sockaddr *to, u_int *tolen) { return recvfromto_nat_t(s, buf, buflen, flags, from, fromlen, to, tolen, NULL, NULL); } int sendto_nat_t(int s, const void *buf, size_t buflen, int flags, struct sockaddr *to, u_int tolen, void *ipsec) { #ifdef IP_IPSECFLOWINFO if (ipsec) { struct iovec iov[1]; struct msghdr msg; struct cmsghdr *cmsg; union { struct cmsghdr hdr; char buf[CMSG_SPACE(sizeof(u_int32_t))]; } cmsgbuf; iov[0].iov_base = (char *)buf; iov[0].iov_len = buflen; memset(&msg, 0, sizeof(msg)); memset(&cmsgbuf, 0, sizeof(cmsgbuf)); msg.msg_name = to; msg.msg_namelen = tolen; msg.msg_iov = iov; msg.msg_iovlen = 1; msg.msg_control = (caddr_t)&cmsgbuf.buf; msg.msg_controllen = sizeof(cmsgbuf.buf); cmsg = CMSG_FIRSTHDR(&msg); cmsg->cmsg_len = CMSG_LEN(sizeof(u_int32_t)); cmsg->cmsg_level = IPPROTO_IP; cmsg->cmsg_type = IP_IPSECFLOWINFO; memcpy(CMSG_DATA(cmsg), ipsec, sizeof(u_int32_t)); return sendmsg(s, &msg, flags); } #endif return sendto(s, buf, buflen, flags, to, tolen); }