1 /* $KAME: probe.c,v 1.17 2003/10/05 00:09:36 itojun Exp $ */
2
3 /*-
4 * SPDX-License-Identifier: BSD-3-Clause
5 *
6 * Copyright (C) 1998 WIDE Project.
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
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 * 3. Neither the name of the project nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * $FreeBSD$
34 */
35
36 #include <sys/param.h>
37 #include <sys/capsicum.h>
38 #include <sys/dnv.h>
39 #include <sys/nv.h>
40 #include <sys/socket.h>
41 #include <sys/sysctl.h>
42
43 #include <net/if.h>
44 #include <net/if_dl.h>
45
46 #include <netinet/in.h>
47 #include <netinet6/in6_var.h>
48 #include <netinet/icmp6.h>
49 #include <netinet6/nd6.h>
50
51 #include <arpa/inet.h>
52
53 #include <capsicum_helpers.h>
54 #include <errno.h>
55 #include <stdlib.h>
56 #include <string.h>
57 #include <syslog.h>
58 #include <unistd.h>
59
60 #include <libcasper.h>
61 #include <libcasper_service.h>
62
63 #include "rtsold.h"
64
65 static int
getsocket(int * sockp,int proto)66 getsocket(int *sockp, int proto)
67 {
68 cap_rights_t rights;
69 int sock;
70
71 if (*sockp >= 0)
72 return (0);
73
74 if ((sock = socket(AF_INET6, SOCK_RAW, proto)) < 0)
75 return (-1);
76 cap_rights_init(&rights, CAP_CONNECT, CAP_SEND);
77 if (caph_rights_limit(sock, &rights) != 0)
78 return (-1);
79 *sockp = sock;
80
81 return (0);
82 }
83
84 static ssize_t
sendpacket(int sock,struct sockaddr_in6 * dst,uint32_t ifindex,int hoplimit,const void * data,size_t len)85 sendpacket(int sock, struct sockaddr_in6 *dst, uint32_t ifindex, int hoplimit,
86 const void *data, size_t len)
87 {
88 uint8_t cmsg[CMSG_SPACE(sizeof(struct in6_pktinfo)) +
89 CMSG_SPACE(sizeof(int))];
90 struct msghdr hdr;
91 struct iovec iov;
92 struct in6_pktinfo *pi;
93 struct cmsghdr *cm;
94
95 memset(&hdr, 0, sizeof(hdr));
96 hdr.msg_name = dst;
97 hdr.msg_namelen = sizeof(*dst);
98 hdr.msg_iov = &iov;
99 hdr.msg_iovlen = 1;
100 hdr.msg_control = cmsg;
101 hdr.msg_controllen = sizeof(cmsg);
102
103 iov.iov_base = __DECONST(void *, data);
104 iov.iov_len = len;
105
106 /* Specify the outbound interface. */
107 cm = CMSG_FIRSTHDR(&hdr);
108 cm->cmsg_level = IPPROTO_IPV6;
109 cm->cmsg_type = IPV6_PKTINFO;
110 cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
111 pi = (struct in6_pktinfo *)(void *)CMSG_DATA(cm);
112 memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/
113 pi->ipi6_ifindex = ifindex;
114
115 /* Specify the hop limit of the packet for safety. */
116 cm = CMSG_NXTHDR(&hdr, cm);
117 cm->cmsg_level = IPPROTO_IPV6;
118 cm->cmsg_type = IPV6_HOPLIMIT;
119 cm->cmsg_len = CMSG_LEN(sizeof(int));
120 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
121
122 return (sendmsg(sock, &hdr, 0));
123 }
124
125 static int
probe_defrouters(uint32_t ifindex,uint32_t linkid)126 probe_defrouters(uint32_t ifindex, uint32_t linkid)
127 {
128 static int probesock = -1;
129 struct sockaddr_in6 dst;
130 struct in6_defrouter *p, *ep;
131 char *buf;
132 size_t len;
133 int mib[4];
134
135 if (ifindex == 0)
136 return (0);
137 if (getsocket(&probesock, IPPROTO_NONE) != 0)
138 return (-1);
139
140 mib[0] = CTL_NET;
141 mib[1] = PF_INET6;
142 mib[2] = IPPROTO_ICMPV6;
143 mib[3] = ICMPV6CTL_ND6_DRLIST;
144 if (sysctl(mib, nitems(mib), NULL, &len, NULL, 0) < 0)
145 return (-1);
146 if (len == 0)
147 return (0);
148
149 memset(&dst, 0, sizeof(dst));
150 dst.sin6_family = AF_INET6;
151 dst.sin6_len = sizeof(dst);
152
153 buf = malloc(len);
154 if (buf == NULL)
155 return (-1);
156 if (sysctl(mib, nitems(mib), buf, &len, NULL, 0) < 0)
157 return (-1);
158 ep = (struct in6_defrouter *)(void *)(buf + len);
159 for (p = (struct in6_defrouter *)(void *)buf; p < ep; p++) {
160 if (ifindex != p->if_index)
161 continue;
162 if (!IN6_IS_ADDR_LINKLOCAL(&p->rtaddr.sin6_addr))
163 continue;
164 dst.sin6_addr = p->rtaddr.sin6_addr;
165 dst.sin6_scope_id = linkid;
166 (void)sendpacket(probesock, &dst, ifindex, 1, NULL, 0);
167 }
168 free(buf);
169
170 return (0);
171 }
172
173 static int
rssend(uint32_t ifindex,uint32_t linkid,const void * data,size_t len)174 rssend(uint32_t ifindex, uint32_t linkid, const void *data, size_t len)
175 {
176 static int rssock = -1;
177 struct sockaddr_in6 dst;
178 ssize_t n;
179
180 if (getsocket(&rssock, IPPROTO_ICMPV6) != 0)
181 return (-1);
182
183 memset(&dst, 0, sizeof(dst));
184 dst.sin6_family = AF_INET6;
185 dst.sin6_len = sizeof(dst);
186 dst.sin6_addr = (struct in6_addr)IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
187 dst.sin6_scope_id = linkid;
188
189 n = sendpacket(rssock, &dst, ifindex, 255, data, len);
190 if (n < 0 || (size_t)n != len)
191 return (-1);
192 return (0);
193 }
194
195 int
cap_probe_defrouters(cap_channel_t * cap,struct ifinfo * ifinfo)196 cap_probe_defrouters(cap_channel_t *cap, struct ifinfo *ifinfo)
197 {
198 #ifdef WITH_CASPER
199 nvlist_t *nvl;
200 int error;
201
202 nvl = nvlist_create(0);
203 nvlist_add_string(nvl, "cmd", "probe_defrouters");
204 nvlist_add_number(nvl, "ifindex", ifinfo->sdl->sdl_index);
205 nvlist_add_number(nvl, "linkid", ifinfo->linkid);
206
207 nvl = cap_xfer_nvlist(cap, nvl);
208 if (nvl == NULL)
209 return (errno);
210 error = (int)dnvlist_get_number(nvl, "error", 0);
211 nvlist_destroy(nvl);
212 errno = error;
213 return (error == 0 ? 0 : -1);
214 #else
215 (void)cap;
216 return (probe_defrouters(ifinfo->sdl->sdl_index, ifinfo->linkid));
217 #endif
218 }
219
220 int
cap_rssend(cap_channel_t * cap,struct ifinfo * ifinfo)221 cap_rssend(cap_channel_t *cap, struct ifinfo *ifinfo)
222 {
223 int error;
224
225 #ifdef WITH_CASPER
226 nvlist_t *nvl = nvlist_create(0);
227 nvlist_add_string(nvl, "cmd", "rssend");
228 nvlist_add_number(nvl, "ifindex", ifinfo->sdl->sdl_index);
229 nvlist_add_number(nvl, "linkid", ifinfo->linkid);
230 nvlist_add_binary(nvl, "data", ifinfo->rs_data, ifinfo->rs_datalen);
231
232 nvl = cap_xfer_nvlist(cap, nvl);
233 if (nvl == NULL)
234 return (errno);
235 error = (int)dnvlist_get_number(nvl, "error", 0);
236 nvlist_destroy(nvl);
237 errno = error;
238 #else
239 (void)cap;
240 error = rssend(ifinfo->sdl->sdl_index, ifinfo->linkid, ifinfo->rs_data,
241 ifinfo->rs_datalen);
242 #endif
243
244 ifinfo->probes++;
245 if (error != 0 && (errno != ENETDOWN || dflag > 0)) {
246 error = errno;
247 warnmsg(LOG_ERR, __func__, "sendmsg on %s: %s",
248 ifinfo->ifname, strerror(errno));
249 errno = error;
250 }
251 return (error == 0 ? 0 : -1);
252 }
253
254 #ifdef WITH_CASPER
255 static int
sendmsg_command(const char * cmd,const nvlist_t * limits __unused,nvlist_t * nvlin,nvlist_t * nvlout __unused)256 sendmsg_command(const char *cmd, const nvlist_t *limits __unused, nvlist_t *nvlin,
257 nvlist_t *nvlout __unused)
258 {
259 const void *data;
260 size_t len;
261 uint32_t ifindex, linkid;
262 int error;
263
264 if (strcmp(cmd, "probe_defrouters") != 0 &&
265 strcmp(cmd, "rssend") != 0)
266 return (EINVAL);
267
268 ifindex = (uint32_t)nvlist_get_number(nvlin, "ifindex");
269 linkid = (uint32_t)nvlist_get_number(nvlin, "linkid");
270 if (strcmp(cmd, "probe_defrouters") == 0) {
271 error = probe_defrouters(ifindex, linkid);
272 } else {
273 data = nvlist_get_binary(nvlin, "data", &len);
274 error = rssend(ifindex, linkid, data, len);
275 }
276 if (error != 0)
277 return (errno);
278 return (0);
279 }
280
281 CREATE_SERVICE("rtsold.sendmsg", NULL, sendmsg_command, 0);
282 #endif /* WITH_CASPER */
283