usr.sbin/rtsold/cap_sendmsg.c

   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
  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
  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
 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
 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
 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
 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
 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 */