1 /* $OpenBSD: lsack.c,v 1.8 2019/12/28 09:25:24 denis Exp $ */ 2 3 /* 4 * Copyright (c) 2004, 2005, 2007 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/ip6.h> 23 #include <arpa/inet.h> 24 25 #include <stdlib.h> 26 #include <string.h> 27 28 #include "ospf6d.h" 29 #include "ospf6.h" 30 #include "log.h" 31 #include "ospfe.h" 32 33 int send_ls_ack(struct iface *, struct in6_addr, struct ibuf *); 34 struct ibuf *prepare_ls_ack(struct iface *); 35 void start_ls_ack_tx_timer_now(struct iface *); 36 37 /* link state acknowledgement packet handling */ 38 struct ibuf * 39 prepare_ls_ack(struct iface *iface) 40 { 41 struct ibuf *buf; 42 43 if ((buf = ibuf_open(iface->mtu - sizeof(struct ip6_hdr))) == NULL) { 44 log_warn("prepare_ls_ack"); 45 return (NULL); 46 } 47 48 /* OSPF header */ 49 if (gen_ospf_hdr(buf, iface, PACKET_TYPE_LS_ACK)) { 50 log_warn("prepare_ls_ack"); 51 ibuf_free(buf); 52 return (NULL); 53 } 54 55 return (buf); 56 } 57 58 int 59 send_ls_ack(struct iface *iface, struct in6_addr addr, struct ibuf *buf) 60 { 61 /* calculate checksum */ 62 if (upd_ospf_hdr(buf, iface)) { 63 log_warn("send_ls_ack"); 64 return (-1); 65 } 66 67 if (send_packet(iface, buf, &addr) == -1) { 68 log_warn("send_ls_ack"); 69 return (-1); 70 } 71 return (0); 72 } 73 74 int 75 send_direct_ack(struct iface *iface, struct in6_addr addr, void *d, size_t len) 76 { 77 struct ibuf *buf; 78 int ret; 79 80 if ((buf = prepare_ls_ack(iface)) == NULL) 81 return (-1); 82 83 /* LS ack(s) */ 84 if (ibuf_add(buf, d, len)) { 85 log_warn("send_direct_ack"); 86 ibuf_free(buf); 87 return (-1); 88 } 89 90 ret = send_ls_ack(iface, addr, buf); 91 ibuf_free(buf); 92 return (ret); 93 } 94 95 void 96 recv_ls_ack(struct nbr *nbr, char *buf, u_int16_t len) 97 { 98 struct lsa_hdr lsa_hdr; 99 100 switch (nbr->state) { 101 case NBR_STA_DOWN: 102 case NBR_STA_ATTEMPT: 103 case NBR_STA_INIT: 104 case NBR_STA_2_WAY: 105 case NBR_STA_XSTRT: 106 case NBR_STA_SNAP: 107 log_debug("recv_ls_ack: packet ignored in state %s, " 108 "neighbor ID %s", nbr_state_name(nbr->state), 109 inet_ntoa(nbr->id)); 110 break; 111 case NBR_STA_XCHNG: 112 case NBR_STA_LOAD: 113 case NBR_STA_FULL: 114 while (len >= sizeof(lsa_hdr)) { 115 memcpy(&lsa_hdr, buf, sizeof(lsa_hdr)); 116 117 if (lsa_hdr_check(nbr, &lsa_hdr)) { 118 /* try both list in case of DROTHER */ 119 if (nbr->iface->state & IF_STA_DROTHER) 120 (void)ls_retrans_list_del( 121 nbr->iface->self, &lsa_hdr); 122 (void)ls_retrans_list_del(nbr, &lsa_hdr); 123 } 124 125 buf += sizeof(lsa_hdr); 126 len -= sizeof(lsa_hdr); 127 } 128 if (len > 0) { 129 log_warnx("recv_ls_ack: bad packet size, " 130 "neighbor ID %s", inet_ntoa(nbr->id)); 131 return; 132 } 133 break; 134 default: 135 fatalx("recv_ls_ack: unknown neighbor state"); 136 } 137 } 138 139 int 140 lsa_hdr_check(struct nbr *nbr, struct lsa_hdr *lsa_hdr) 141 { 142 /* invalid age */ 143 if ((ntohs(lsa_hdr->age) < 1) || (ntohs(lsa_hdr->age) > MAX_AGE)) { 144 log_debug("lsa_hdr_check: invalid age, neighbor ID %s", 145 inet_ntoa(nbr->id)); 146 return (0); 147 } 148 149 /* invalid type */ 150 switch (ntohs(lsa_hdr->type)) { 151 case LSA_TYPE_LINK: 152 case LSA_TYPE_ROUTER: 153 case LSA_TYPE_NETWORK: 154 case LSA_TYPE_INTER_A_PREFIX: 155 case LSA_TYPE_INTER_A_ROUTER: 156 case LSA_TYPE_INTRA_A_PREFIX: 157 case LSA_TYPE_EXTERNAL: 158 break; 159 default: 160 log_debug("lsa_hdr_check: invalid LSA type %d, neighbor ID %s", 161 lsa_hdr->type, inet_ntoa(nbr->id)); 162 return (0); 163 } 164 165 /* invalid sequence number */ 166 if (ntohl(lsa_hdr->seq_num) == RESV_SEQ_NUM) { 167 log_debug("ls_hdr_check: invalid seq num, neighbor ID %s", 168 inet_ntoa(nbr->id)); 169 return (0); 170 } 171 172 return (1); 173 } 174 175 /* link state ack list */ 176 void 177 ls_ack_list_add(struct iface *iface, struct lsa_hdr *lsa) 178 { 179 struct lsa_entry *le; 180 181 if (lsa == NULL) 182 fatalx("ls_ack_list_add: no LSA header"); 183 184 if ((le = calloc(1, sizeof(*le))) == NULL) 185 fatal("ls_ack_list_add"); 186 187 if (ls_ack_list_empty(iface)) 188 start_ls_ack_tx_timer(iface); 189 190 TAILQ_INSERT_TAIL(&iface->ls_ack_list, le, entry); 191 le->le_lsa = lsa; 192 iface->ls_ack_cnt++; 193 194 /* reschedule now if we have enough for a full packet */ 195 if (iface->ls_ack_cnt > 196 ((iface->mtu - PACKET_HDR) / sizeof(struct lsa_hdr))) { 197 start_ls_ack_tx_timer_now(iface); 198 } 199 } 200 201 void 202 ls_ack_list_free(struct iface *iface, struct lsa_entry *le) 203 { 204 TAILQ_REMOVE(&iface->ls_ack_list, le, entry); 205 free(le->le_lsa); 206 free(le); 207 208 iface->ls_ack_cnt--; 209 } 210 211 void 212 ls_ack_list_clr(struct iface *iface) 213 { 214 struct lsa_entry *le; 215 216 while ((le = TAILQ_FIRST(&iface->ls_ack_list)) != NULL) { 217 TAILQ_REMOVE(&iface->ls_ack_list, le, entry); 218 free(le->le_lsa); 219 free(le); 220 } 221 iface->ls_ack_cnt = 0; 222 } 223 224 int 225 ls_ack_list_empty(struct iface *iface) 226 { 227 return (TAILQ_EMPTY(&iface->ls_ack_list)); 228 } 229 230 /* timers */ 231 /* ARGSUSED */ 232 void 233 ls_ack_tx_timer(int fd, short event, void *arg) 234 { 235 struct in6_addr addr; 236 struct iface *iface = arg; 237 struct lsa_entry *le, *nle; 238 struct nbr *nbr; 239 struct ibuf *buf; 240 int cnt; 241 242 while (!ls_ack_list_empty(iface)) { 243 if ((buf = prepare_ls_ack(iface)) == NULL) 244 fatal("ls_ack_tx_timer"); 245 cnt = 0; 246 247 for (le = TAILQ_FIRST(&iface->ls_ack_list); le != NULL; 248 le = nle) { 249 nle = TAILQ_NEXT(le, entry); 250 if (ibuf_left(buf) < sizeof(struct lsa_hdr)) 251 break; 252 if (ibuf_add(buf, le->le_lsa, sizeof(struct lsa_hdr))) 253 break; 254 ls_ack_list_free(iface, le); 255 cnt++; 256 } 257 if (cnt == 0) { 258 log_warnx("ls_ack_tx_timer: lost in space"); 259 ibuf_free(buf); 260 return; 261 } 262 263 /* send LS ack(s) but first set correct destination */ 264 switch (iface->type) { 265 case IF_TYPE_POINTOPOINT: 266 inet_pton(AF_INET6, AllSPFRouters, &addr); 267 send_ls_ack(iface, addr, buf); 268 break; 269 case IF_TYPE_BROADCAST: 270 if (iface->state & IF_STA_DRORBDR) 271 inet_pton(AF_INET6, AllSPFRouters, &addr); 272 else 273 inet_pton(AF_INET6, AllDRouters, &addr); 274 send_ls_ack(iface, addr, buf); 275 break; 276 case IF_TYPE_NBMA: 277 case IF_TYPE_POINTOMULTIPOINT: 278 case IF_TYPE_VIRTUALLINK: 279 LIST_FOREACH(nbr, &iface->nbr_list, entry) { 280 if (nbr == iface->self) 281 continue; 282 if (!(nbr->state & NBR_STA_FLOOD)) 283 continue; 284 send_ls_ack(iface, nbr->addr, buf); 285 } 286 break; 287 default: 288 fatalx("lsa_ack_tx_timer: unknown interface type"); 289 } 290 ibuf_free(buf); 291 } 292 } 293 294 void 295 start_ls_ack_tx_timer(struct iface *iface) 296 { 297 struct timeval tv; 298 299 timerclear(&tv); 300 tv.tv_sec = iface->rxmt_interval / 2; 301 302 if (evtimer_add(&iface->lsack_tx_timer, &tv) == -1) 303 fatal("start_ls_ack_tx_timer"); 304 } 305 306 void 307 start_ls_ack_tx_timer_now(struct iface *iface) 308 { 309 struct timeval tv; 310 311 timerclear(&tv); 312 if (evtimer_add(&iface->lsack_tx_timer, &tv) == -1) 313 fatal("start_ls_ack_tx_timer_now"); 314 } 315 316 void 317 stop_ls_ack_tx_timer(struct iface *iface) 318 { 319 if (evtimer_del(&iface->lsack_tx_timer) == -1) 320 fatal("stop_ls_ack_tx_timer"); 321 } 322