1 /* $OpenBSD: probe.c,v 1.2 2010/05/26 13:56:07 nicm 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 <arpa/inet.h> 23 #include <sys/time.h> 24 #include <sys/socket.h> 25 #include <stdlib.h> 26 #include <string.h> 27 #include <event.h> 28 29 #include "igmp.h" 30 #include "dvmrpd.h" 31 #include "dvmrp.h" 32 #include "log.h" 33 #include "dvmrpe.h" 34 35 extern struct dvmrpd_conf *deconf; 36 37 /* DVMRP probe packet handling */ 38 int 39 send_probe(struct iface *iface) 40 { 41 struct sockaddr_in dst; 42 struct ibuf *buf; 43 struct dvmrp_hdr *dvmrp_hdr; 44 struct nbr *nbr; 45 int ret = 0; 46 47 if (iface->passive) 48 return (0); 49 50 if ((buf = ibuf_open(iface->mtu - sizeof(struct ip))) == NULL) 51 fatal("send_probe"); 52 53 /* DVMRP header */ 54 if (gen_dvmrp_hdr(buf, iface, DVMRP_CODE_PROBE)) 55 goto fail; 56 57 /* generation ID */ 58 ibuf_add(buf, &iface->gen_id, sizeof(iface->gen_id)); 59 60 /* generate neighbor list */ 61 LIST_FOREACH(nbr, &iface->nbr_list, entry) { 62 if (nbr->state > NBR_STA_DOWN) 63 ibuf_add(buf, &nbr->id, sizeof(nbr->id)); 64 } 65 66 /* set destination address */ 67 dst.sin_family = AF_INET; 68 dst.sin_len = sizeof(struct sockaddr_in); 69 inet_aton(AllDVMRPRouters, &dst.sin_addr); 70 71 /* update chksum */ 72 dvmrp_hdr = ibuf_seek(buf, 0, sizeof(dvmrp_hdr)); 73 dvmrp_hdr->chksum = in_cksum(buf->buf, buf->wpos); 74 75 ret = send_packet(iface, buf->buf, buf->wpos, &dst); 76 ibuf_free(buf); 77 return (ret); 78 fail: 79 log_warn("send_probe"); 80 ibuf_free(buf); 81 return (-1); 82 } 83 84 void 85 recv_probe(struct iface *iface, struct in_addr src, u_int32_t src_ip, 86 u_int8_t capabilities, char *buf, u_int16_t len) 87 { 88 struct nbr *nbr = NULL; 89 u_int32_t gen_id; 90 u_int32_t nbr_id; 91 92 LIST_FOREACH(nbr, &iface->nbr_list, entry) { 93 if (nbr->id.s_addr == src_ip) 94 break; 95 } 96 97 memcpy(&gen_id, buf, sizeof(gen_id)); 98 len -= sizeof(gen_id); 99 buf += sizeof(gen_id); 100 101 if (!nbr) { 102 nbr = nbr_new(src_ip, iface, 0); 103 nbr->gen_id = gen_id; 104 nbr->capabilities = capabilities; 105 nbr->addr = src; 106 } 107 108 nbr_fsm(nbr, NBR_EVT_PROBE_RCVD); 109 110 if ((nbr->gen_id != gen_id) || (nbr->capabilities != capabilities)) { 111 if (!nbr->compat) 112 nbr_fsm(nbr, NBR_EVT_1_WAY_RCVD); 113 nbr->gen_id = gen_id; 114 nbr->capabilities = capabilities; 115 116 /* XXX handle nbr change! */ 117 } 118 119 while (len >= sizeof(nbr_id)) { 120 memcpy(&nbr_id, buf, sizeof(nbr_id)); 121 if (nbr_id == iface->addr.s_addr) { 122 /* seen myself */ 123 if (nbr->state < NBR_STA_2_WAY) 124 nbr_fsm(nbr, NBR_EVT_2_WAY_RCVD); 125 break; 126 } 127 buf += sizeof(nbr_id); 128 len -= sizeof(nbr_id); 129 } 130 131 if (len == 0) { 132 nbr_fsm(nbr, NBR_EVT_1_WAY_RCVD); 133 return; 134 } 135 136 /* XXX len correct?? */ 137 138 return; 139 } 140