1 /* $OpenBSD: report.c,v 1.13 2024/08/21 09:18:47 florian Exp $ */
2
3 /*
4 * Copyright (c) 2005, 2006 Esben Norby <norby@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/socket.h>
21 #include <netinet/in.h>
22 #include <netinet/ip.h>
23 #include <arpa/inet.h>
24
25 #include <stdlib.h>
26 #include <string.h>
27
28 #include "igmp.h"
29 #include "dvmrpd.h"
30 #include "dvmrp.h"
31 #include "dvmrpe.h"
32 #include "log.h"
33
34 extern struct dvmrpd_conf *deconf;
35
36 void rr_list_remove(struct route_report *);
37
38 /* DVMRP report packet handling */
39 int
send_report(struct iface * iface,struct in_addr addr,void * data,int len)40 send_report(struct iface *iface, struct in_addr addr, void *data, int len)
41 {
42 struct sockaddr_in dst;
43 struct ibuf *buf;
44 int ret = 0;
45
46 log_debug("send_report: interface %s addr %s",
47 iface->name, inet_ntoa(addr));
48
49 if (iface->passive)
50 return (0);
51
52 if ((buf = ibuf_open(iface->mtu - sizeof(struct ip))) == NULL)
53 fatal("send_report");
54
55 /* DVMRP header */
56 if (gen_dvmrp_hdr(buf, iface, DVMRP_CODE_REPORT))
57 goto fail;
58
59 ibuf_add(buf, data, len);
60
61 dst.sin_family = AF_INET;
62 dst.sin_len = sizeof(struct sockaddr_in);
63 dst.sin_addr.s_addr = addr.s_addr;
64
65 ret = send_packet(iface, buf, &dst);
66 ibuf_free(buf);
67 return (ret);
68 fail:
69 log_warn("send_report");
70 ibuf_free(buf);
71 return (-1);
72 }
73
74 void
recv_report(struct nbr * nbr,char * buf,u_int16_t len)75 recv_report(struct nbr *nbr, char *buf, u_int16_t len)
76 {
77 struct route_report rr;
78 u_int32_t netid, netmask;
79 u_int8_t metric, netid_len, prefixlen;
80
81 log_debug("recv_report: neighbor ID %s", inet_ntoa(nbr->id));
82
83 if ((nbr->state != NBR_STA_2_WAY) && (!nbr->compat)) {
84 log_warnx("recv_report: neighbor %s not in state %s",
85 inet_ntoa(nbr->id), "2-WAY");
86 return;
87 }
88
89 /* parse route report */
90 do {
91 /*
92 * get netmask
93 *
94 * The netmask in a DVMRP report is only represented by 3 bytes,
95 * to cope with that we read 4 bytes and shift 8 bits.
96 * The most significant part of the mask is always 255.
97 */
98
99 /* read four bytes */
100 memcpy(&netmask, buf, sizeof(netmask));
101 /* ditch one byte, since we only need three */
102 netmask = ntohl(netmask) >> 8;
103 netmask = htonl(netmask);
104
105 /* set the highest byte to 255 */
106 netmask |= htonl(0xff000000);
107 buf += 3;
108 len -= 3;
109
110 prefixlen = mask2prefixlen(netmask);
111 netid_len = PREFIX_SIZE(prefixlen);
112
113 do {
114 /*
115 * get netid
116 *
117 * The length of the netid is depending on the above
118 * netmask.
119 * Read 4 bytes and use the netmask from above to
120 * determine the netid.
121 */
122 memcpy(&netid, buf, sizeof(netid));
123 netid &= netmask;
124
125 buf += netid_len;
126 len -= netid_len;
127
128 /* get metric */
129 memcpy(&metric, buf, sizeof(metric));
130 buf += sizeof(metric);
131 len -= sizeof(metric);
132
133 rr.net.s_addr = netid;
134 rr.mask.s_addr = netmask;
135 rr.nexthop = nbr->id;
136 rr.metric = (metric & METRIC_MASK);
137
138 /* ifindex */
139 rr.ifindex = nbr->iface->ifindex;
140
141 /* send route report to RDE */
142 dvmrpe_imsg_compose_rde(IMSG_ROUTE_REPORT, nbr->peerid,
143 0, &rr, sizeof(rr));
144
145 } while (!(metric & LAST_MASK) && (len > 0));
146 } while (len > 0);
147
148 return;
149 }
150
151 /* timers */
152 void
report_timer(int fd,short event,void * arg)153 report_timer(int fd, short event, void *arg)
154 {
155 struct timeval tv;
156
157 /* request full route report */
158 dvmrpe_imsg_compose_rde(IMSG_FULL_ROUTE_REPORT, 0, 0, NULL, 0);
159
160 /* restart report timer */
161 timerclear(&tv);
162 tv.tv_sec = ROUTE_REPORT_INTERVAL;
163 evtimer_add(&deconf->report_timer, &tv);
164 }
165
166 int
start_report_timer(void)167 start_report_timer(void)
168 {
169 struct timeval tv;
170
171 timerclear(&tv);
172 tv.tv_sec = MIN_FLASH_UPDATE_INTERVAL; /* XXX safe?? */
173 return (evtimer_add(&deconf->report_timer, &tv));
174 }
175
176 int
stop_report_timer(void)177 stop_report_timer(void)
178 {
179 return (evtimer_del(&deconf->report_timer));
180 }
181
182 /* route report list */
183 void
rr_list_add(struct rr_head * rr_list,struct route_report * rr)184 rr_list_add(struct rr_head *rr_list, struct route_report *rr)
185 {
186 struct rr_entry *le;
187
188 if (rr == NULL)
189 fatalx("rr_list_add: no route report");
190
191 if ((le = calloc(1, sizeof(*le))) == NULL)
192 fatal("rr_list_add");
193
194 TAILQ_INSERT_TAIL(rr_list, le, entry);
195 le->re = rr;
196 rr->refcount++;
197 }
198
199 void
rr_list_remove(struct route_report * rr)200 rr_list_remove(struct route_report *rr)
201 {
202 if (--rr->refcount == 0)
203 free(rr);
204 }
205
206 void
rr_list_clr(struct rr_head * rr_list)207 rr_list_clr(struct rr_head *rr_list)
208 {
209 struct rr_entry *le;
210
211 while ((le = TAILQ_FIRST(rr_list)) != NULL) {
212 TAILQ_REMOVE(rr_list, le, entry);
213 rr_list_remove(le->re);
214 free(le);
215 }
216 }
217
218 void
rr_list_send(struct rr_head * rr_list,struct iface * xiface,struct nbr * nbr)219 rr_list_send(struct rr_head *rr_list, struct iface *xiface, struct nbr *nbr)
220 {
221 struct rr_entry *le, *le2;
222 struct ibuf *buf;
223 struct iface *iface;
224 struct in_addr addr;
225 u_int32_t netid, netmask;
226 u_int8_t metric, netid_len, prefixlen;
227
228 /* set destination */
229 if (xiface == NULL) {
230 /* directly to a nbr */
231 iface = nbr->iface;
232 addr = nbr->addr;
233 } else {
234 /* multicast on interface */
235 iface = xiface;
236 inet_pton(AF_INET, AllDVMRPRouters, &addr);
237 }
238
239 while (!TAILQ_EMPTY(rr_list)) {
240 if ((buf = ibuf_open(iface->mtu - sizeof(struct ip))) == NULL)
241 fatal("rr_list_send");
242
243 prefixlen = 0;
244 while (((le = TAILQ_FIRST(rr_list)) != NULL) &&
245 (ibuf_size(buf) < 1000)) {
246 /* netmask */
247 netmask = le->re->mask.s_addr;
248 if (prefixlen != mask2prefixlen(netmask)) {
249 prefixlen = mask2prefixlen(netmask);
250 netmask = ntohl(netmask) << 8;
251 netmask = htonl(netmask);
252 ibuf_add(buf, &netmask, 3);
253 }
254 netid_len = PREFIX_SIZE(prefixlen);
255
256 /* netid */
257 netid = le->re->net.s_addr;
258 ibuf_add(buf, &netid, netid_len);
259
260 /* metric */
261 if (iface->ifindex == le->re->ifindex)
262 /* poison reverse */
263 metric = le->re->metric + INFINITY_METRIC;
264 else
265 metric = le->re->metric;
266
267 /*
268 * determine if we need to flag last entry with current
269 * netmask.
270 */
271 le2 = TAILQ_NEXT(le, entry);
272 if (le2 != NULL) {
273 if (mask2prefixlen(le2->re->mask.s_addr) !=
274 prefixlen)
275 metric = metric | LAST_MASK;
276 } else {
277 metric = metric | LAST_MASK;
278 }
279
280 ibuf_add(buf, &metric, sizeof(metric));
281
282 TAILQ_REMOVE(rr_list, le, entry);
283 rr_list_remove(le->re);
284 free(le);
285 }
286 send_report(iface, addr, ibuf_data(buf), ibuf_size(buf));
287 ibuf_free(buf);
288 }
289 }
290