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
34 #include <sys/param.h>
35 #include <sys/capsicum.h>
36 #include <sys/dnv.h>
37 #include <sys/nv.h>
38 #include <sys/socket.h>
39 #include <sys/sysctl.h>
40
41 #include <net/if.h>
42 #include <net/if_dl.h>
43
44 #include <netinet/in.h>
45 #include <netinet6/in6_var.h>
46 #include <netinet/icmp6.h>
47 #include <netinet6/nd6.h>
48
49 #include <arpa/inet.h>
50
51 #include <capsicum_helpers.h>
52 #include <errno.h>
53 #include <stdlib.h>
54 #include <string.h>
55 #include <syslog.h>
56 #include <unistd.h>
57
58 #include <libcasper.h>
59 #include <libcasper_service.h>
60
61 #include "rtsold.h"
62
63 static int
getsocket(int * sockp,int proto)64 getsocket(int *sockp, int proto)
65 {
66 cap_rights_t rights;
67 int sock;
68
69 if (*sockp >= 0)
70 return (0);
71
72 if ((sock = socket(AF_INET6, SOCK_RAW, proto)) < 0)
73 return (-1);
74 cap_rights_init(&rights, CAP_CONNECT, CAP_SEND);
75 if (caph_rights_limit(sock, &rights) != 0)
76 return (-1);
77 *sockp = sock;
78
79 return (0);
80 }
81
82 static ssize_t
sendpacket(int sock,struct sockaddr_in6 * dst,uint32_t ifindex,int hoplimit,const void * data,size_t len)83 sendpacket(int sock, struct sockaddr_in6 *dst, uint32_t ifindex, int hoplimit,
84 const void *data, size_t len)
85 {
86 uint8_t cmsg[CMSG_SPACE(sizeof(struct in6_pktinfo)) +
87 CMSG_SPACE(sizeof(int))];
88 struct msghdr hdr;
89 struct iovec iov;
90 struct in6_pktinfo *pi;
91 struct cmsghdr *cm;
92
93 memset(&hdr, 0, sizeof(hdr));
94 hdr.msg_name = dst;
95 hdr.msg_namelen = sizeof(*dst);
96 hdr.msg_iov = &iov;
97 hdr.msg_iovlen = 1;
98 hdr.msg_control = cmsg;
99 hdr.msg_controllen = sizeof(cmsg);
100
101 iov.iov_base = __DECONST(void *, data);
102 iov.iov_len = len;
103
104 /* Specify the outbound interface. */
105 cm = CMSG_FIRSTHDR(&hdr);
106 cm->cmsg_level = IPPROTO_IPV6;
107 cm->cmsg_type = IPV6_PKTINFO;
108 cm->cmsg_len = CMSG_LEN(sizeof(struct in6_pktinfo));
109 pi = (struct in6_pktinfo *)(void *)CMSG_DATA(cm);
110 memset(&pi->ipi6_addr, 0, sizeof(pi->ipi6_addr)); /*XXX*/
111 pi->ipi6_ifindex = ifindex;
112
113 /* Specify the hop limit of the packet for safety. */
114 cm = CMSG_NXTHDR(&hdr, cm);
115 cm->cmsg_level = IPPROTO_IPV6;
116 cm->cmsg_type = IPV6_HOPLIMIT;
117 cm->cmsg_len = CMSG_LEN(sizeof(int));
118 memcpy(CMSG_DATA(cm), &hoplimit, sizeof(int));
119
120 return (sendmsg(sock, &hdr, 0));
121 }
122
123 static int
probe_defrouters(uint32_t ifindex,uint32_t linkid)124 probe_defrouters(uint32_t ifindex, uint32_t linkid)
125 {
126 static int probesock = -1;
127 struct sockaddr_in6 dst;
128 struct in6_defrouter *p, *ep;
129 char *buf;
130 size_t len;
131 int mib[4];
132
133 if (ifindex == 0)
134 return (0);
135 if (getsocket(&probesock, IPPROTO_NONE) != 0)
136 return (-1);
137
138 mib[0] = CTL_NET;
139 mib[1] = PF_INET6;
140 mib[2] = IPPROTO_ICMPV6;
141 mib[3] = ICMPV6CTL_ND6_DRLIST;
142 if (sysctl(mib, nitems(mib), NULL, &len, NULL, 0) < 0)
143 return (-1);
144 if (len == 0)
145 return (0);
146
147 memset(&dst, 0, sizeof(dst));
148 dst.sin6_family = AF_INET6;
149 dst.sin6_len = sizeof(dst);
150
151 buf = malloc(len);
152 if (buf == NULL)
153 return (-1);
154 if (sysctl(mib, nitems(mib), buf, &len, NULL, 0) < 0)
155 return (-1);
156 ep = (struct in6_defrouter *)(void *)(buf + len);
157 for (p = (struct in6_defrouter *)(void *)buf; p < ep; p++) {
158 if (ifindex != p->if_index)
159 continue;
160 if (!IN6_IS_ADDR_LINKLOCAL(&p->rtaddr.sin6_addr))
161 continue;
162 dst.sin6_addr = p->rtaddr.sin6_addr;
163 dst.sin6_scope_id = linkid;
164 (void)sendpacket(probesock, &dst, ifindex, 1, NULL, 0);
165 }
166 free(buf);
167
168 return (0);
169 }
170
171 static int
rssend(uint32_t ifindex,uint32_t linkid,const void * data,size_t len)172 rssend(uint32_t ifindex, uint32_t linkid, const void *data, size_t len)
173 {
174 static int rssock = -1;
175 struct sockaddr_in6 dst;
176 ssize_t n;
177
178 if (getsocket(&rssock, IPPROTO_ICMPV6) != 0)
179 return (-1);
180
181 memset(&dst, 0, sizeof(dst));
182 dst.sin6_family = AF_INET6;
183 dst.sin6_len = sizeof(dst);
184 dst.sin6_addr = (struct in6_addr)IN6ADDR_LINKLOCAL_ALLROUTERS_INIT;
185 dst.sin6_scope_id = linkid;
186
187 n = sendpacket(rssock, &dst, ifindex, 255, data, len);
188 if (n < 0 || (size_t)n != len)
189 return (-1);
190 return (0);
191 }
192
193 int
cap_probe_defrouters(cap_channel_t * cap,struct ifinfo * ifinfo)194 cap_probe_defrouters(cap_channel_t *cap, struct ifinfo *ifinfo)
195 {
196 #ifdef WITH_CASPER
197 nvlist_t *nvl;
198 int error;
199
200 nvl = nvlist_create(0);
201 nvlist_add_string(nvl, "cmd", "probe_defrouters");
202 nvlist_add_number(nvl, "ifindex", ifinfo->sdl->sdl_index);
203 nvlist_add_number(nvl, "linkid", ifinfo->linkid);
204
205 nvl = cap_xfer_nvlist(cap, nvl);
206 if (nvl == NULL)
207 return (errno);
208 error = (int)dnvlist_get_number(nvl, "error", 0);
209 nvlist_destroy(nvl);
210 errno = error;
211 return (error == 0 ? 0 : -1);
212 #else
213 (void)cap;
214 return (probe_defrouters(ifinfo->sdl->sdl_index, ifinfo->linkid));
215 #endif
216 }
217
218 int
cap_rssend(cap_channel_t * cap,struct ifinfo * ifinfo)219 cap_rssend(cap_channel_t *cap, struct ifinfo *ifinfo)
220 {
221 int error;
222
223 #ifdef WITH_CASPER
224 nvlist_t *nvl = nvlist_create(0);
225 nvlist_add_string(nvl, "cmd", "rssend");
226 nvlist_add_number(nvl, "ifindex", ifinfo->sdl->sdl_index);
227 nvlist_add_number(nvl, "linkid", ifinfo->linkid);
228 nvlist_add_binary(nvl, "data", ifinfo->rs_data, ifinfo->rs_datalen);
229
230 nvl = cap_xfer_nvlist(cap, nvl);
231 if (nvl == NULL)
232 return (errno);
233 error = (int)dnvlist_get_number(nvl, "error", 0);
234 nvlist_destroy(nvl);
235 errno = error;
236 #else
237 (void)cap;
238 error = rssend(ifinfo->sdl->sdl_index, ifinfo->linkid, ifinfo->rs_data,
239 ifinfo->rs_datalen);
240 #endif
241
242 ifinfo->probes++;
243 if (error != 0 && (errno != ENETDOWN || dflag > 0)) {
244 error = errno;
245 warnmsg(LOG_ERR, __func__, "sendmsg on %s: %s",
246 ifinfo->ifname, strerror(errno));
247 errno = error;
248 }
249 return (error == 0 ? 0 : -1);
250 }
251
252 #ifdef WITH_CASPER
253 static int
sendmsg_command(const char * cmd,const nvlist_t * limits __unused,nvlist_t * nvlin,nvlist_t * nvlout __unused)254 sendmsg_command(const char *cmd, const nvlist_t *limits __unused, nvlist_t *nvlin,
255 nvlist_t *nvlout __unused)
256 {
257 const void *data;
258 size_t len;
259 uint32_t ifindex, linkid;
260 int error;
261
262 if (strcmp(cmd, "probe_defrouters") != 0 &&
263 strcmp(cmd, "rssend") != 0)
264 return (EINVAL);
265
266 ifindex = (uint32_t)nvlist_get_number(nvlin, "ifindex");
267 linkid = (uint32_t)nvlist_get_number(nvlin, "linkid");
268 if (strcmp(cmd, "probe_defrouters") == 0) {
269 error = probe_defrouters(ifindex, linkid);
270 } else {
271 data = nvlist_get_binary(nvlin, "data", &len);
272 error = rssend(ifindex, linkid, data, len);
273 }
274 if (error != 0)
275 return (errno);
276 return (0);
277 }
278
279 CREATE_SERVICE("rtsold.sendmsg", NULL, sendmsg_command, 0);
280 #endif /* WITH_CASPER */
281