1 /*	$OpenBSD: pfe_route.c,v 1.15 2026/03/02 19:28:01 rsadowski Exp $	*/
2 
3 /*
4  * Copyright (c) 2009 - 2011 Reyk Floeter <reyk@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <sys/types.h>
20 #include <sys/queue.h>
21 #include <sys/socket.h>
22 #include <sys/uio.h>
23 
24 #include <netinet/in.h>
25 #include <net/route.h>
26 #include <arpa/inet.h>
27 
28 #include <limits.h>
29 #include <stddef.h>
30 #include <stdio.h>
31 #include <unistd.h>
32 #include <string.h>
33 #include <errno.h>
34 
35 #include "relayd.h"
36 #include "log.h"
37 
38 void
39 init_routes(struct relayd *env)
40 {
41 	u_int	 rtfilter;
42 
43 	if (!(env->sc_conf.flags & F_NEEDRT))
44 		return;
45 
46 	if ((env->sc_rtsock = socket(AF_ROUTE, SOCK_RAW, 0)) == -1)
47 		fatal("%s: failed to open routing socket", __func__);
48 
49 	rtfilter = ROUTE_FILTER(0);
50 	if (setsockopt(env->sc_rtsock, AF_ROUTE, ROUTE_MSGFILTER,
51 	    &rtfilter, sizeof(rtfilter)) == -1)
52 		fatal("%s: ROUTE_MSGFILTER", __func__);
53 }
54 
55 void
56 sync_routes(struct relayd *env, struct router *rt)
57 {
58 	struct netroute		*nr;
59 	struct host		*host;
60 	char			 buf[HOST_NAME_MAX+1];
61 	struct ctl_netroute	 crt;
62 
63 	if (!(env->sc_conf.flags & F_NEEDRT))
64 		return;
65 
66 	TAILQ_FOREACH(nr, &rt->rt_netroutes, nr_entry) {
67 		print_host(&nr->nr_conf.ss, buf, sizeof(buf));
68 		TAILQ_FOREACH(host, &rt->rt_gwtable->hosts, entry) {
69 			if (host->up == HOST_UNKNOWN)
70 				continue;
71 
72 			log_debug("%s: "
73 			    "router %s route %s/%d gateway %s %s priority %d",
74 			    __func__,
75 			    rt->rt_conf.name, buf, nr->nr_conf.prefixlen,
76 			    host->conf.name,
77 			    HOST_ISUP(host->up) ? "up" : "down",
78 			    host->conf.priority);
79 
80 			crt.up = host->up;
81 			memcpy(&crt.nr, &nr->nr_conf, sizeof(nr->nr_conf));
82 			memcpy(&crt.host, &host->conf, sizeof(host->conf));
83 			memcpy(&crt.rt, &rt->rt_conf, sizeof(rt->rt_conf));
84 
85 			proc_compose(env->sc_ps, PROC_PARENT,
86 			    IMSG_RTMSG, &crt, sizeof(crt));
87 		}
88 	}
89 }
90 
91 static void
92 pfe_apply_prefixlen(struct sockaddr_storage *ss, int af, int len)
93 {
94 	int q, r, off;
95 	uint8_t *b = (uint8_t *)ss;
96 
97 	q = len >> 3;
98 	r = len & 7;
99 
100 	bzero(ss, sizeof(*ss));
101 	ss->ss_family = af;
102 	switch (af) {
103 	case AF_INET:
104 		ss->ss_len = sizeof(struct sockaddr_in);
105 		off = offsetof(struct sockaddr_in, sin_addr);
106 		break;
107 	case AF_INET6:
108 		ss->ss_len = sizeof(struct sockaddr_in6);
109 		off = offsetof(struct sockaddr_in6, sin6_addr);
110 		break;
111 	default:
112 		fatal("%s: invalid address family", __func__);
113 	}
114 	if (q > 0)
115 		memset(b + off, 0xff, q);
116 	if (r > 0)
117 		b[off + q] = (0xff00 >> r) & 0xff;
118 }
119 
120 #define ROUNDUP(a) \
121 	((a) > 0 ? (1 + (((a) - 1) | (sizeof(long) - 1))) : sizeof(long))
122 
123 int
124 pfe_route(struct relayd *env, struct ctl_netroute *crt)
125 {
126 	struct iovec			 iov[5];
127 	struct rt_msghdr		 hdr;
128 	struct sockaddr_storage		 dst, gw, mask, label;
129 	struct sockaddr_rtlabel		*sr = (struct sockaddr_rtlabel *)&label;
130 	int				 iovcnt = 0;
131 	char				*gwname;
132 
133 	bzero(&hdr, sizeof(hdr));
134 	hdr.rtm_msglen = sizeof(hdr);
135 	hdr.rtm_version = RTM_VERSION;
136 	hdr.rtm_type = HOST_ISUP(crt->up) ? RTM_ADD : RTM_DELETE;
137 	hdr.rtm_flags = RTF_STATIC | RTF_GATEWAY | RTF_MPATH;
138 	hdr.rtm_seq = env->sc_rtseq++;
139 	hdr.rtm_addrs = RTA_DST | RTA_GATEWAY | RTA_NETMASK;
140 	hdr.rtm_tableid = crt->rt.rtable;
141 	hdr.rtm_priority = crt->host.priority;
142 
143 	iov[iovcnt].iov_base = &hdr;
144 	iov[iovcnt++].iov_len = sizeof(hdr);
145 
146 	dst = crt->nr.ss;
147 	gw = crt->host.ss;
148 	gwname = crt->host.name;
149 	pfe_apply_prefixlen(&mask, dst.ss_family, crt->nr.prefixlen);
150 
151 	iov[iovcnt].iov_base = &dst;
152 	iov[iovcnt++].iov_len = ROUNDUP(dst.ss_len);
153 	hdr.rtm_msglen += ROUNDUP(dst.ss_len);
154 
155 	iov[iovcnt].iov_base = &gw;
156 	iov[iovcnt++].iov_len = ROUNDUP(gw.ss_len);
157 	hdr.rtm_msglen += ROUNDUP(gw.ss_len);
158 
159 	iov[iovcnt].iov_base = &mask;
160 	iov[iovcnt++].iov_len = ROUNDUP(mask.ss_len);
161 	hdr.rtm_msglen += ROUNDUP(mask.ss_len);
162 
163 	if (strlen(crt->rt.label)) {
164 		sr->sr_len = sizeof(*sr);
165 		strlcpy(sr->sr_label, crt->rt.label, sizeof(sr->sr_label));
166 
167 		iov[iovcnt].iov_base = &label;
168 		iov[iovcnt++].iov_len = ROUNDUP(label.ss_len);
169 		hdr.rtm_msglen += ROUNDUP(label.ss_len);
170 		hdr.rtm_addrs |= RTA_LABEL;
171 	}
172 
173  retry:
174 	if (writev(env->sc_rtsock, iov, iovcnt) == -1) {
175 		switch (errno) {
176 		case EEXIST:
177 		case ESRCH:
178 			if (hdr.rtm_type == RTM_ADD) {
179 				hdr.rtm_type = RTM_CHANGE;
180 				goto retry;
181 			} else if (hdr.rtm_type == RTM_DELETE) {
182 				/* Ignore */
183 				break;
184 			}
185 			/* FALLTHROUGH */
186 		default:
187 			goto bad;
188 		}
189 	}
190 
191 	log_debug("%s: gateway %s %s", __func__, gwname,
192 	    HOST_ISUP(crt->up) ? "added" : "deleted");
193 
194 	return (0);
195 
196  bad:
197 	log_debug("%s: failed to %s gateway %s: %d %s", __func__,
198 	    HOST_ISUP(crt->up) ? "add" : "delete", gwname,
199 	    errno, strerror(errno));
200 
201 	return (-1);
202 }