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/param.h>
43 /*
44 * Verify that we are at least 4.4 BSD
45 */
46 #if defined(BSD)
47 #if BSD >= 199306
48
49 #include <sys/socket.h>
50 #include <sys/filio.h>
51 #include <sys/time.h>
52
53 #include <net/if.h>
54 #include <net/if_dl.h>
55 #include <net/if_types.h>
56 #include <net/route.h>
57
58 #include <netinet/in.h>
59 #include <netinet/if_ether.h>
60
61 #include <arpa/inet.h>
62
63 #include <errno.h>
64 #include <stdio.h>
65 #include <stdlib.h>
66 #include <string.h>
67 #include <syslog.h>
68 #include <unistd.h>
69
70 #include "report.h"
71
72
73 static int rtmsg(int);
74
75 static int s = -1; /* routing socket */
76
77
78 /*
79 * Open the routing socket
80 */
getsocket()81 static void getsocket () {
82 if (s < 0) {
83 s = socket(PF_ROUTE, SOCK_RAW, 0);
84 if (s < 0) {
85 report(LOG_ERR, "socket %s", strerror(errno));
86 exit(1);
87 }
88 } else {
89 /*
90 * Drain the socket of any unwanted routing messages.
91 */
92 int n;
93 char buf[512];
94
95 ioctl(s, FIONREAD, &n);
96 while (n > 0) {
97 read(s, buf, sizeof buf);
98 ioctl(s, FIONREAD, &n);
99 }
100 }
101 }
102
103 static struct sockaddr_in so_mask = {8, 0, 0, { 0xffffffff}};
104 static struct sockaddr_in blank_sin = {sizeof(blank_sin), AF_INET }, sin_m;
105 static struct sockaddr_dl blank_sdl = {sizeof(blank_sdl), AF_LINK }, sdl_m;
106 static int expire_time, flags, doing_proxy;
107 static struct {
108 struct rt_msghdr m_rtm;
109 char m_space[512];
110 } m_rtmsg;
111
112 /*
113 * Set an individual arp entry
114 */
115 int
bsd_arp_set(struct in_addr * ia,char * eaddr,int len)116 bsd_arp_set(struct in_addr *ia, char *eaddr, int len)
117 {
118 struct sockaddr_in *sin = &sin_m;
119 struct sockaddr_dl *sdl;
120 struct rt_msghdr *rtm = &(m_rtmsg.m_rtm);
121 u_char *ea;
122 struct timespec tp;
123 int op = RTM_ADD;
124
125 getsocket();
126 sdl_m = blank_sdl;
127 sin_m = blank_sin;
128 sin->sin_addr = *ia;
129
130 ea = (u_char *)LLADDR(&sdl_m);
131 bcopy(eaddr, ea, len);
132 sdl_m.sdl_alen = len;
133 doing_proxy = flags = expire_time = 0;
134
135 /* make arp entry temporary */
136 clock_gettime(CLOCK_MONOTONIC, &tp);
137 expire_time = tp.tv_sec + 20 * 60;
138
139 tryagain:
140 if (rtmsg(RTM_GET) < 0) {
141 report(LOG_WARNING, "rtmget: %s", strerror(errno));
142 return (1);
143 }
144 sin = (struct sockaddr_in *)(rtm + 1);
145 sdl = (struct sockaddr_dl *)(sin->sin_len + (char *)sin);
146 if (sin->sin_addr.s_addr == sin_m.sin_addr.s_addr) {
147 if (sdl->sdl_family == AF_LINK &&
148 !(rtm->rtm_flags & RTF_GATEWAY)) switch (sdl->sdl_type) {
149 case IFT_ETHER: case IFT_FDDI: case IFT_ISO88023:
150 case IFT_ISO88024: case IFT_ISO88025:
151 op = RTM_CHANGE;
152 goto overwrite;
153 }
154 if (doing_proxy == 0) {
155 report(LOG_WARNING, "set: can only proxy for %s\n",
156 inet_ntoa(sin->sin_addr));
157 return (1);
158 }
159 goto tryagain;
160 }
161 overwrite:
162 if (sdl->sdl_family != AF_LINK) {
163 report(LOG_WARNING,
164 "cannot intuit interface index and type for %s\n",
165 inet_ntoa(sin->sin_addr));
166 return (1);
167 }
168 sdl_m.sdl_type = sdl->sdl_type;
169 sdl_m.sdl_index = sdl->sdl_index;
170 return (rtmsg(op));
171 }
172
173
174 static int
rtmsg(int cmd)175 rtmsg(int cmd)
176 {
177 static int seq;
178 int rlen;
179 struct rt_msghdr *rtm = &m_rtmsg.m_rtm;
180 char *cp = m_rtmsg.m_space;
181 int l;
182
183 errno = 0;
184 bzero((char *)&m_rtmsg, sizeof(m_rtmsg));
185 rtm->rtm_flags = flags;
186 rtm->rtm_version = RTM_VERSION;
187
188 switch (cmd) {
189 default:
190 report(LOG_ERR, "set_arp: internal wrong cmd - exiting");
191 exit(1);
192 case RTM_ADD:
193 case RTM_CHANGE:
194 rtm->rtm_addrs |= RTA_GATEWAY;
195 rtm->rtm_rmx.rmx_expire = expire_time;
196 rtm->rtm_inits = RTV_EXPIRE;
197 rtm->rtm_flags |= (RTF_HOST | RTF_STATIC | RTF_LLDATA);
198 if (doing_proxy) {
199 rtm->rtm_addrs |= RTA_NETMASK;
200 rtm->rtm_flags &= ~RTF_HOST;
201 }
202 /* FALLTHROUGH */
203 case RTM_GET:
204 rtm->rtm_addrs |= RTA_DST;
205 }
206 #define NEXTADDR(w, s) \
207 if (rtm->rtm_addrs & (w)) { \
208 bcopy((char *)&s, cp, sizeof(s)); cp += sizeof(s);}
209
210 NEXTADDR(RTA_DST, sin_m);
211 NEXTADDR(RTA_GATEWAY, sdl_m);
212 NEXTADDR(RTA_NETMASK, so_mask);
213
214 rtm->rtm_msglen = cp - (char *)&m_rtmsg;
215
216 l = rtm->rtm_msglen;
217 rtm->rtm_seq = ++seq;
218 rtm->rtm_type = cmd;
219 if ((rlen = write(s, (char *)&m_rtmsg, l)) < 0) {
220 if ((errno != ESRCH) && !(errno == EEXIST && cmd == RTM_ADD)){
221 report(LOG_WARNING, "writing to routing socket: %s",
222 strerror(errno));
223 return (-1);
224 }
225 }
226 do {
227 l = read(s, (char *)&m_rtmsg, sizeof(m_rtmsg));
228 } while (l > 0 && (rtm->rtm_type != cmd || rtm->rtm_seq != seq || rtm->rtm_pid != getpid()));
229 if (l < 0)
230 report(LOG_WARNING, "arp: read from routing socket: %s\n",
231 strerror(errno));
232 return (0);
233 }
234
235 #endif /* BSD */
236 #endif /* BSD >= 199306 */
237