1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1984, 1993
5 * The Regents of the University of California. All rights reserved.
6 * Copyright (c) 1994
7 * Geoffrey M. Rehmet, All rights reserved.
8 *
9 * This code is derived from software which forms part of the 4.4-Lite
10 * Berkeley software distribution, which was in derived from software
11 * contributed to Berkeley by Sun Microsystems, Inc.
12 *
13 * Redistribution and use in source and binary forms, with or without
14 * modification, are permitted provided that the following conditions
15 * are met:
16 * 1. Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 * 2. Redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution.
21 * 3. Neither the name of the University nor the names of its contributors
22 * may be used to endorse or promote products derived from this software
23 * without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35 * SUCH DAMAGE.
36 */
37
38 /*
39 * from arp.c 8.2 (Berkeley) 1/2/94
40 */
41
42 #include <sys/cdefs.h>
43 __FBSDID("$FreeBSD$");
44
45 #include <sys/param.h>
46 /*
47 * Verify that we are at least 4.4 BSD
48 */
49 #if defined(BSD)
50 #if BSD >= 199306
51
52 #include <sys/socket.h>
53 #include <sys/filio.h>
54 #include <sys/time.h>
55
56 #include <net/if.h>
57 #include <net/if_dl.h>
58 #include <net/if_types.h>
59 #include <net/route.h>
60
61 #include <netinet/in.h>
62 #include <netinet/if_ether.h>
63
64 #include <arpa/inet.h>
65
66 #include <errno.h>
67 #include <stdio.h>
68 #include <stdlib.h>
69 #include <string.h>
70 #include <syslog.h>
71 #include <unistd.h>
72
73 #include "report.h"
74
75
76 static int rtmsg(int);
77
78 static int s = -1; /* routing socket */
79
80
81 /*
82 * Open the routing socket
83 */
getsocket()84 static void getsocket () {
85 if (s < 0) {
86 s = socket(PF_ROUTE, SOCK_RAW, 0);
87 if (s < 0) {
88 report(LOG_ERR, "socket %s", strerror(errno));
89 exit(1);
90 }
91 } else {
92 /*
93 * Drain the socket of any unwanted routing messages.
94 */
95 int n;
96 char buf[512];
97
98 ioctl(s, FIONREAD, &n);
99 while (n > 0) {
100 read(s, buf, sizeof buf);
101 ioctl(s, FIONREAD, &n);
102 }
103 }
104 }
105
106 static struct sockaddr_in so_mask = {8, 0, 0, { 0xffffffff}};
107 static struct sockaddr_in blank_sin = {sizeof(blank_sin), AF_INET }, sin_m;
108 static struct sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m;
109 static int expire_time, flags, doing_proxy;
110 static struct {
111 struct rt_msghdr m_rtm;
112 char m_space[512];
113 } m_rtmsg;
114
115 /*
116 * Set an individual arp entry
117 */
bsd_arp_set(ia,eaddr,len)118 int bsd_arp_set(ia, eaddr, len)
119 struct in_addr *ia;
120 char *eaddr;
121 int len;
122 {
123 struct sockaddr_in *sin = &sin_m;
124 struct sockaddr_dl *sdl;
125 struct rt_msghdr *rtm = &(m_rtmsg.m_rtm);
126 u_char *ea;
127 struct timespec tp;
128 int op = RTM_ADD;
129
130 getsocket();
131 sdl_m = blank_sdl;
132 sin_m = blank_sin;
133 sin->sin_addr = *ia;
134
135 ea = (u_char *)LLADDR(&sdl_m);
136 bcopy(eaddr, ea, len);
137 sdl_m.sdl_alen = len;
138 doing_proxy = flags = expire_time = 0;
139
140 /* make arp entry temporary */
141 clock_gettime(CLOCK_MONOTONIC, &tp);
142 expire_time = tp.tv_sec + 20 * 60;
143
144 tryagain:
145 if (rtmsg(RTM_GET) < 0) {
146 report(LOG_WARNING, "rtmget: %s", strerror(errno));
147 return (1);
148 }
149 sin = (struct sockaddr_in *)(rtm + 1);
150 sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin);
151 if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) {
152 if (sdl->sdl_family == AF_LINK &&
153 !(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) {
154 case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023:
155 case IFT_ISO88024: case IFT_ISO88025:
156 op = RTM_CHANGE;
157 goto overwrite;
158 }
159 if (doing_proxy == 0) {
160 report(LOG_WARNING, "set: can only proxy for %s\n",
161 inet_ntoa(sin->sin_addr));
162 return (1);
163 }
164 goto tryagain;
165 }
166 overwrite:
167 if (sdl->sdl_family != AF_LINK) {
168 report(LOG_WARNING,
169 "cannot intuit interface index and type for %s\n",
170 inet_ntoa(sin->sin_addr));
171 return (1);
172 }
173 sdl_m.sdl_type = sdl->sdl_type;
174 sdl_m.sdl_index = sdl->sdl_index;
175 return (rtmsg(op));
176 }
177
178
rtmsg(cmd)179 static int rtmsg(cmd)
180 int cmd;
181 {
182 static int seq;
183 int rlen;
184 struct rt_msghdr *rtm = &m_rtmsg.m_rtm;
185 char *cp = m_rtmsg.m_space;
186 int l;
187
188 errno = 0;
189 bzero((char *)&m_rtmsg, sizeof(m_rtmsg));
190 rtm->rtm_flags = flags;
191 rtm->rtm_version = RTM_VERSION;
192
193 switch (cmd) {
194 default:
195 report(LOG_ERR, "set_arp: internal wrong cmd - exiting");
196 exit(1);
197 case RTM_ADD:
198 case RTM_CHANGE:
199 rtm->rtm_addrs |= RTA_GATEWAY;
200 rtm->rtm_rmx.rmx_expire = expire_time;
201 rtm->rtm_inits = RTV_EXPIRE;
202 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC | RTF_LLDATA);
203 if (doing_proxy) {
204 rtm->rtm_addrs |= RTA_NETMASK;
205 rtm->rtm_flags &= ~RTF_HOST;
206 }
207 /* FALLTHROUGH */
208 case RTM_GET:
209 rtm->rtm_addrs |= RTA_DST;
210 }
211 #define NEXTADDR(w, s) \
212 if (rtm->rtm_addrs & (w)) { \
213 bcopy((char *)&s, cp, sizeof(s)); cp += sizeof(s);}
214
215 NEXTADDR(RTA_DST, sin_m);
216 NEXTADDR(RTA_GATEWAY, sdl_m);
217 NEXTADDR(RTA_NETMASK, so_mask);
218
219 rtm->rtm_msglen = cp - (char *)&m_rtmsg;
220
221 l = rtm->rtm_msglen;
222 rtm->rtm_seq = ++seq;
223 rtm->rtm_type = cmd;
224 if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) {
225 if ((errno != ESRCH) && !(errno == EEXIST && cmd == RTM_ADD)){
226 report(LOG_WARNING, "writing to routing socket: %s",
227 strerror(errno));
228 return (-1);
229 }
230 }
231 do {
232 l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg));
233 } while (l > 0 && (rtm->rtm_type != cmd || rtm->rtm_seq != seq || rtm->rtm_pid != getpid()));
234 if (l < 0)
235 report(LOG_WARNING, "arp: read from routing socket: %s\n",
236 strerror(errno));
237 return (0);
238 }
239
240 #endif /* BSD */
241 #endif /* BSD >= 199306 */
242