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