1 /*
2 * sys-bsd.c - System-dependent procedures for setting up
3 * PPP interfaces on bsd-4.4-ish systems (including 386BSD, NetBSD, etc.)
4 *
5 * SPDX-License-Identifier: BSD-1-Clause
6 *
7 * Copyright (c) 1989 Carnegie Mellon University.
8 * All rights reserved.
9 *
10 * Redistribution and use in source and binary forms are permitted
11 * provided that the above copyright notice and this paragraph are
12 * duplicated in all such forms and that any documentation,
13 * advertising materials, and other materials related to such
14 * distribution and use acknowledge that the software was developed
15 * by Carnegie Mellon University. The name of the
16 * University may not be used to endorse or promote products derived
17 * from this software without specific prior written permission.
18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
20 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
21 *
22 */
23
24 /*
25 * TODO:
26 */
27
28 #include <sys/param.h>
29 #include <sys/socket.h>
30 #include <net/if.h>
31 #include <net/route.h>
32 #include <net/if_dl.h>
33 #include <netinet/in.h>
34 #include <netinet/if_ether.h>
35 #include <arpa/inet.h>
36 #include <netinet/in_systm.h>
37 #include <netinet/ip.h>
38 #include <sys/un.h>
39
40 #include <errno.h>
41 #include <stdio.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <sys/sysctl.h>
45 #include <termios.h>
46 #include <unistd.h>
47
48 #include "layer.h"
49 #include "mbuf.h"
50 #include "log.h"
51 #include "id.h"
52 #include "timer.h"
53 #include "fsm.h"
54 #include "defs.h"
55 #include "iplist.h"
56 #include "throughput.h"
57 #include "slcompress.h"
58 #include "lqr.h"
59 #include "hdlc.h"
60 #include "ncpaddr.h"
61 #include "ipcp.h"
62 #include "ipv6cp.h"
63 #include "descriptor.h"
64 #include "lcp.h"
65 #include "ccp.h"
66 #include "link.h"
67 #include "mp.h"
68 #include "ncp.h"
69 #include "filter.h"
70 #ifndef NORADIUS
71 #include "radius.h"
72 #endif
73 #include "bundle.h"
74 #include "iface.h"
75 #include "arp.h"
76
77 /*
78 * SET_SA_FAMILY - set the sa_family field of a struct sockaddr,
79 * if it exists.
80 */
81 #define SET_SA_FAMILY(addr, family) \
82 memset((char *) &(addr), '\0', sizeof(addr)); \
83 addr.sa_family = (family); \
84 addr.sa_len = sizeof(addr);
85
86
87 #if RTM_VERSION >= 3
88
89 /*
90 * arp_SetProxy - Make a proxy ARP entry for the peer.
91 */
92 static struct {
93 struct rt_msghdr hdr;
94 struct sockaddr_in dst;
95 struct sockaddr_dl hwa;
96 char extra[128];
97 } arpmsg;
98
99 static int
arp_ProxySub(struct bundle * bundle,struct in_addr addr,int add)100 arp_ProxySub(struct bundle *bundle, struct in_addr addr, int add)
101 {
102 int routes;
103
104 /*
105 * Get the hardware address of an interface on the same subnet as our local
106 * address.
107 */
108
109 memset(&arpmsg, 0, sizeof arpmsg);
110 if (!arp_EtherAddr(addr, &arpmsg.hwa, 0)) {
111 log_Printf(LogWARN, "%s: Cannot determine ethernet address for proxy ARP\n",
112 inet_ntoa(addr));
113 return 0;
114 }
115 routes = ID0socket(PF_ROUTE, SOCK_RAW, AF_INET);
116 if (routes < 0) {
117 log_Printf(LogERROR, "arp_SetProxy: opening routing socket: %s\n",
118 strerror(errno));
119 return 0;
120 }
121 arpmsg.hdr.rtm_type = add ? RTM_ADD : RTM_DELETE;
122 arpmsg.hdr.rtm_flags = RTF_ANNOUNCE | RTF_HOST | RTF_STATIC | RTF_LLDATA;
123 arpmsg.hdr.rtm_version = RTM_VERSION;
124 arpmsg.hdr.rtm_seq = ++bundle->routing_seq;
125 arpmsg.hdr.rtm_addrs = RTA_DST | RTA_GATEWAY;
126 arpmsg.hdr.rtm_inits = RTV_EXPIRE;
127 arpmsg.dst.sin_len = sizeof(struct sockaddr_in);
128 arpmsg.dst.sin_family = AF_INET;
129 arpmsg.dst.sin_addr.s_addr = addr.s_addr;
130
131 arpmsg.hdr.rtm_msglen = (char *) &arpmsg.hwa - (char *) &arpmsg
132 + arpmsg.hwa.sdl_len;
133
134
135 if (ID0write(routes, &arpmsg, arpmsg.hdr.rtm_msglen) < 0 &&
136 !(!add && errno == ESRCH)) {
137 log_Printf(LogERROR, "%s proxy arp entry %s: %s\n",
138 add ? "Add" : "Delete", inet_ntoa(addr), strerror(errno));
139 close(routes);
140 return 0;
141 }
142 close(routes);
143 return 1;
144 }
145
146 int
arp_SetProxy(struct bundle * bundle,struct in_addr addr)147 arp_SetProxy(struct bundle *bundle, struct in_addr addr)
148 {
149 return (arp_ProxySub(bundle, addr, 1));
150 }
151
152 /*
153 * arp_ClearProxy - Delete the proxy ARP entry for the peer.
154 */
155 int
arp_ClearProxy(struct bundle * bundle,struct in_addr addr)156 arp_ClearProxy(struct bundle *bundle, struct in_addr addr)
157 {
158 return (arp_ProxySub(bundle, addr, 0));
159 }
160
161 #else /* RTM_VERSION */
162
163 /*
164 * arp_SetProxy - Make a proxy ARP entry for the peer.
165 */
166 int
arp_SetProxy(struct bundle * bundle,struct in_addr addr,int s)167 arp_SetProxy(struct bundle *bundle, struct in_addr addr, int s)
168 {
169 struct arpreq arpreq;
170 struct {
171 struct sockaddr_dl sdl;
172 char space[128];
173 } dls;
174
175 memset(&arpreq, '\0', sizeof arpreq);
176
177 /*
178 * Get the hardware address of an interface on the same subnet as our local
179 * address.
180 */
181 if (!arp_EtherAddr(addr, &dls.sdl, 1)) {
182 log_Printf(LOG_PHASE_BIT, "Cannot determine ethernet address for "
183 "proxy ARP\n");
184 return 0;
185 }
186 arpreq.arp_ha.sa_len = sizeof(struct sockaddr);
187 arpreq.arp_ha.sa_family = AF_UNSPEC;
188 memcpy(arpreq.arp_ha.sa_data, LLADDR(&dls.sdl), dls.sdl.sdl_alen);
189 SET_SA_FAMILY(arpreq.arp_pa, AF_INET);
190 ((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr;
191 arpreq.arp_flags = ATF_PERM | ATF_PUBL;
192 if (ID0ioctl(s, SIOCSARP, (caddr_t) & arpreq) < 0) {
193 log_Printf(LogERROR, "arp_SetProxy: ioctl(SIOCSARP): %s\n",
194 strerror(errno));
195 return 0;
196 }
197 return 1;
198 }
199
200 /*
201 * arp_ClearProxy - Delete the proxy ARP entry for the peer.
202 */
203 int
arp_ClearProxy(struct bundle * bundle,struct in_addr addr,int s)204 arp_ClearProxy(struct bundle *bundle, struct in_addr addr, int s)
205 {
206 struct arpreq arpreq;
207
208 memset(&arpreq, '\0', sizeof arpreq);
209 SET_SA_FAMILY(arpreq.arp_pa, AF_INET);
210 ((struct sockaddr_in *)&arpreq.arp_pa)->sin_addr.s_addr = addr.s_addr;
211 if (ID0ioctl(s, SIOCDARP, (caddr_t) & arpreq) < 0) {
212 log_Printf(LogERROR, "arp_ClearProxy: ioctl(SIOCDARP): %s\n",
213 strerror(errno));
214 return 0;
215 }
216 return 1;
217 }
218
219 #endif /* RTM_VERSION */
220
221
222 /*
223 * arp_EtherAddr - get the hardware address of an interface on the
224 * same subnet as ipaddr.
225 */
226
227 int
arp_EtherAddr(struct in_addr ipaddr,struct sockaddr_dl * hwaddr,int verbose)228 arp_EtherAddr(struct in_addr ipaddr, struct sockaddr_dl *hwaddr,
229 int verbose)
230 {
231 int mib[6], skip;
232 size_t needed;
233 char *buf, *ptr, *end;
234 struct if_msghdr *ifm;
235 struct ifa_msghdr *ifam;
236 struct sockaddr_dl *dl;
237 struct sockaddr *sa[RTAX_MAX];
238
239 mib[0] = CTL_NET;
240 mib[1] = PF_ROUTE;
241 mib[2] = 0;
242 mib[3] = 0;
243 mib[4] = NET_RT_IFLIST;
244 mib[5] = 0;
245
246 if (sysctl(mib, 6, NULL, &needed, NULL, 0) < 0) {
247 log_Printf(LogERROR, "arp_EtherAddr: sysctl: estimate: %s\n",
248 strerror(errno));
249 return 0;
250 }
251
252 if ((buf = malloc(needed)) == NULL)
253 return 0;
254
255 if (sysctl(mib, 6, buf, &needed, NULL, 0) < 0) {
256 free(buf);
257 return 0;
258 }
259 end = buf + needed;
260
261 ptr = buf;
262 while (ptr < end) {
263 ifm = (struct if_msghdr *)ptr; /* On if_msghdr */
264 if (ifm->ifm_type != RTM_IFINFO)
265 break;
266 dl = (struct sockaddr_dl *)(ifm + 1); /* Single _dl at end */
267 skip = (ifm->ifm_flags & (IFF_UP | IFF_BROADCAST | IFF_POINTOPOINT |
268 IFF_NOARP | IFF_LOOPBACK)) != (IFF_UP | IFF_BROADCAST);
269 ptr += ifm->ifm_msglen; /* First ifa_msghdr */
270 while (ptr < end) {
271 ifam = (struct ifa_msghdr *)ptr; /* Next ifa_msghdr (alias) */
272 if (ifam->ifam_type != RTM_NEWADDR) /* finished ? */
273 break;
274 ptr += ifam->ifam_msglen;
275 if (skip || (ifam->ifam_addrs & (RTA_NETMASK|RTA_IFA)) !=
276 (RTA_NETMASK|RTA_IFA))
277 continue;
278 /* Found a candidate. Do the addresses match ? */
279 if (log_IsKept(LogDEBUG) &&
280 ptr == (char *)ifm + ifm->ifm_msglen + ifam->ifam_msglen)
281 log_Printf(LogDEBUG, "%.*s interface is a candidate for proxy\n",
282 dl->sdl_nlen, dl->sdl_data);
283
284 iface_ParseHdr(ifam, sa);
285
286 if (sa[RTAX_IFA]->sa_family == AF_INET) {
287 struct sockaddr_in *ifa, *netmask;
288
289 ifa = (struct sockaddr_in *)sa[RTAX_IFA];
290 netmask = (struct sockaddr_in *)sa[RTAX_NETMASK];
291
292 if (log_IsKept(LogDEBUG)) {
293 char a[16];
294
295 strncpy(a, inet_ntoa(netmask->sin_addr), sizeof a - 1);
296 a[sizeof a - 1] = '\0';
297 log_Printf(LogDEBUG, "Check addr %s, mask %s\n",
298 inet_ntoa(ifa->sin_addr), a);
299 }
300
301 if ((ifa->sin_addr.s_addr & netmask->sin_addr.s_addr) ==
302 (ipaddr.s_addr & netmask->sin_addr.s_addr)) {
303 log_Printf(verbose ? LogPHASE : LogDEBUG,
304 "Found interface %.*s for %s\n", dl->sdl_nlen,
305 dl->sdl_data, inet_ntoa(ipaddr));
306 memcpy(hwaddr, dl, dl->sdl_len);
307 free(buf);
308 return 1;
309 }
310 }
311 }
312 }
313 free(buf);
314
315 return 0;
316 }
317