1 /* $OpenBSD: recvfromto.c,v 1.7 2024/02/26 08:25:51 yasuoka Exp $ */
2 /* adapted from ipsec-tools 0.6 src/racoon/sockmisc.c */
3 /*
4 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the project nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31 #include <sys/types.h>
32 #include <sys/socket.h>
33 #include <sys/uio.h>
34 #include <netinet/in.h>
35 #include <string.h>
36
37 #include "recvfromto.h"
38
39 /*
40 * Receive packet, with src/dst information. It is assumed that necessary
41 * setsockopt() have already performed on socket.
42 */
43 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)44 recvfromto_nat_t(int s, void *buf, size_t buflen, int flags,
45 struct sockaddr *from, u_int *fromlen, struct sockaddr *to, u_int *tolen,
46 void *ipsec, u_int *ipseclen)
47 {
48 int otolen;
49 u_int oipseclen = 0;
50 ssize_t len;
51 struct sockaddr_storage ss;
52 struct msghdr m;
53 struct cmsghdr *cm;
54 struct iovec iov[2];
55 u_char cmsgbuf[256];
56 struct in6_pktinfo *pi;
57 struct sockaddr_in *sin4;
58 socklen_t sslen;
59 struct sockaddr_in6 *sin6;
60
61 sslen = sizeof(ss);
62 if (getsockname(s, (struct sockaddr *)&ss, &sslen) < 0)
63 return -1;
64
65 m.msg_name = (caddr_t)from;
66 m.msg_namelen = *fromlen;
67 iov[0].iov_base = (caddr_t)buf;
68 iov[0].iov_len = buflen;
69 m.msg_iov = iov;
70 m.msg_iovlen = 1;
71 memset(cmsgbuf, 0, sizeof(cmsgbuf));
72 cm = (struct cmsghdr *)cmsgbuf;
73 m.msg_control = (caddr_t)cm;
74 m.msg_controllen = sizeof(cmsgbuf);
75 if ((len = recvmsg(s, &m, flags)) <= 0) {
76 return len;
77 }
78 *fromlen = m.msg_namelen;
79
80 if (ipsec && ipseclen) {
81 oipseclen = *ipseclen;
82 *ipseclen = 0;
83 }
84 otolen = *tolen;
85 *tolen = 0;
86 for (cm = (struct cmsghdr *)CMSG_FIRSTHDR(&m);
87 m.msg_controllen != 0 && cm;
88 cm = (struct cmsghdr *)CMSG_NXTHDR(&m, cm)) {
89 if (ss.ss_family == AF_INET6
90 && cm->cmsg_level == IPPROTO_IPV6
91 && cm->cmsg_type == IPV6_PKTINFO
92 && otolen >= sizeof(*sin6)) {
93 pi = (struct in6_pktinfo *)(CMSG_DATA(cm));
94 *tolen = sizeof(*sin6);
95 sin6 = (struct sockaddr_in6 *)to;
96 memset(sin6, 0, sizeof(*sin6));
97 sin6->sin6_family = AF_INET6;
98 #ifndef __linux__
99 sin6->sin6_len = sizeof(*sin6);
100 #endif
101 memcpy(&sin6->sin6_addr, &pi->ipi6_addr,
102 sizeof(sin6->sin6_addr));
103 /* XXX other cases, such as site-local? */
104 if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr))
105 sin6->sin6_scope_id = pi->ipi6_ifindex;
106 else
107 sin6->sin6_scope_id = 0;
108 sin6->sin6_port =
109 ((struct sockaddr_in6 *)&ss)->sin6_port;
110 otolen = -1; /* "to" already set */
111 continue;
112 }
113 #ifdef IP_IPSECFLOWINFO
114 if (ss.ss_family == AF_INET /* ?? */
115 && cm->cmsg_level == IPPROTO_IP
116 && cm->cmsg_type == IP_IPSECFLOWINFO
117 && oipseclen >= sizeof(u_int32_t)) {
118 *ipseclen = sizeof(u_int32_t);
119 memcpy(ipsec, CMSG_DATA(cm), *ipseclen);
120 continue;
121 }
122 #endif
123 #ifdef __linux__
124 if (ss.ss_family == AF_INET
125 && cm->cmsg_level == IPPROTO_IP
126 && cm->cmsg_type == IP_PKTINFO
127 && otolen >= sizeof(sin4)) {
128 struct in_pktinfo *pi = (struct in_pktinfo *)(CMSG_DATA(cm));
129 *tolen = sizeof(*sin4);
130 sin4 = (struct sockaddr_in *)to;
131 memset(sin4, 0, sizeof(*sin4));
132 sin4->sin_family = AF_INET;
133 memcpy(&sin4->sin_addr, &pi->ipi_addr,
134 sizeof(sin4->sin_addr));
135 sin4->sin_port =
136 ((struct sockaddr_in *)&ss)->sin_port;
137 otolen = -1; /* "to" already set */
138 continue;
139 }
140 #endif
141 #ifdef IPV6_RECVDSTADDR
142 if (ss.ss_family == AF_INET6
143 && cm->cmsg_level == IPPROTO_IPV6
144 && cm->cmsg_type == IPV6_RECVDSTADDR
145 && otolen >= sizeof(*sin6)) {
146 *tolen = sizeof(*sin6);
147 sin6 = (struct sockaddr_in6 *)to;
148 memset(sin6, 0, sizeof(*sin6));
149 sin6->sin6_family = AF_INET6;
150 sin6->sin6_len = sizeof(*sin6);
151 memcpy(&sin6->sin6_addr, CMSG_DATA(cm),
152 sizeof(sin6->sin6_addr));
153 sin6->sin6_port =
154 ((struct sockaddr_in6 *)&ss)->sin6_port;
155 otolen = -1; /* "to" already set */
156 continue;
157 }
158 #endif
159 #ifndef __linux__
160 if (ss.ss_family == AF_INET
161 && cm->cmsg_level == IPPROTO_IP
162 && cm->cmsg_type == IP_RECVDSTADDR
163 && otolen >= sizeof(*sin4)) {
164 *tolen = sizeof(*sin4);
165 sin4 = (struct sockaddr_in *)to;
166 memset(sin4, 0, sizeof(*sin4));
167 sin4->sin_family = AF_INET;
168 sin4->sin_len = sizeof(*sin4);
169 memcpy(&sin4->sin_addr, CMSG_DATA(cm),
170 sizeof(sin4->sin_addr));
171 sin4->sin_port = ((struct sockaddr_in *)&ss)->sin_port;
172 otolen = -1; /* "to" already set */
173 continue;
174 }
175 #endif
176 }
177
178 return len;
179 }
180
181 int
recvfromto(int s,void * buf,size_t buflen,int flags,struct sockaddr * from,u_int * fromlen,struct sockaddr * to,u_int * tolen)182 recvfromto(int s, void *buf, size_t buflen, int flags, struct sockaddr *from,
183 u_int *fromlen, struct sockaddr *to, u_int *tolen)
184 {
185 return recvfromto_nat_t(s, buf, buflen, flags, from, fromlen,
186 to, tolen, NULL, NULL);
187 }
188
189 int
sendto_nat_t(int s,const void * buf,size_t buflen,int flags,struct sockaddr * to,u_int tolen,void * ipsec)190 sendto_nat_t(int s, const void *buf, size_t buflen, int flags,
191 struct sockaddr *to, u_int tolen, void *ipsec)
192 {
193 #ifdef IP_IPSECFLOWINFO
194 if (ipsec) {
195 struct iovec iov[1];
196 struct msghdr msg;
197 struct cmsghdr *cmsg;
198 union {
199 struct cmsghdr hdr;
200 char buf[CMSG_SPACE(sizeof(u_int32_t))];
201 } cmsgbuf;
202
203 iov[0].iov_base = (char *)buf;
204 iov[0].iov_len = buflen;
205 memset(&msg, 0, sizeof(msg));
206 memset(&cmsgbuf, 0, sizeof(cmsgbuf));
207 msg.msg_name = to;
208 msg.msg_namelen = tolen;
209 msg.msg_iov = iov;
210 msg.msg_iovlen = 1;
211 msg.msg_control = (caddr_t)&cmsgbuf.buf;
212 msg.msg_controllen = sizeof(cmsgbuf.buf);
213 cmsg = CMSG_FIRSTHDR(&msg);
214 cmsg->cmsg_len = CMSG_LEN(sizeof(u_int32_t));
215 cmsg->cmsg_level = IPPROTO_IP;
216 cmsg->cmsg_type = IP_IPSECFLOWINFO;
217 memcpy(CMSG_DATA(cmsg), ipsec, sizeof(u_int32_t));
218 return sendmsg(s, &msg, flags);
219 }
220 #endif
221 return sendto(s, buf, buflen, flags, to, tolen);
222 }
223