1 /* $OpenBSD: probe.c,v 1.4 2015/05/05 01:26:37 jsg 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 <stdlib.h> 25 #include <string.h> 26 #include <event.h> 27 28 #include "igmp.h" 29 #include "dvmrpd.h" 30 #include "dvmrp.h" 31 #include "log.h" 32 #include "dvmrpe.h" 33 34 extern struct dvmrpd_conf *deconf; 35 36 /* DVMRP probe packet handling */ 37 int 38 send_probe(struct iface *iface) 39 { 40 struct sockaddr_in dst; 41 struct ibuf *buf; 42 struct dvmrp_hdr *dvmrp_hdr; 43 struct nbr *nbr; 44 int ret = 0; 45 46 if (iface->passive) 47 return (0); 48 49 if ((buf = ibuf_open(iface->mtu - sizeof(struct ip))) == NULL) 50 fatal("send_probe"); 51 52 /* DVMRP header */ 53 if (gen_dvmrp_hdr(buf, iface, DVMRP_CODE_PROBE)) 54 goto fail; 55 56 /* generation ID */ 57 ibuf_add(buf, &iface->gen_id, sizeof(iface->gen_id)); 58 59 /* generate neighbor list */ 60 LIST_FOREACH(nbr, &iface->nbr_list, entry) { 61 if (nbr->state > NBR_STA_DOWN) 62 ibuf_add(buf, &nbr->id, sizeof(nbr->id)); 63 } 64 65 /* set destination address */ 66 dst.sin_family = AF_INET; 67 dst.sin_len = sizeof(struct sockaddr_in); 68 inet_aton(AllDVMRPRouters, &dst.sin_addr); 69 70 /* update chksum */ 71 dvmrp_hdr = ibuf_seek(buf, 0, sizeof(*dvmrp_hdr)); 72 dvmrp_hdr->chksum = in_cksum(buf->buf, buf->wpos); 73 74 ret = send_packet(iface, buf->buf, buf->wpos, &dst); 75 ibuf_free(buf); 76 return (ret); 77 fail: 78 log_warn("send_probe"); 79 ibuf_free(buf); 80 return (-1); 81 } 82 83 void 84 recv_probe(struct iface *iface, struct in_addr src, u_int32_t src_ip, 85 u_int8_t capabilities, char *buf, u_int16_t len) 86 { 87 struct nbr *nbr = NULL; 88 u_int32_t gen_id; 89 u_int32_t nbr_id; 90 91 LIST_FOREACH(nbr, &iface->nbr_list, entry) { 92 if (nbr->id.s_addr == src_ip) 93 break; 94 } 95 96 memcpy(&gen_id, buf, sizeof(gen_id)); 97 len -= sizeof(gen_id); 98 buf += sizeof(gen_id); 99 100 if (!nbr) { 101 nbr = nbr_new(src_ip, iface, 0); 102 nbr->gen_id = gen_id; 103 nbr->capabilities = capabilities; 104 nbr->addr = src; 105 } 106 107 nbr_fsm(nbr, NBR_EVT_PROBE_RCVD); 108 109 if ((nbr->gen_id != gen_id) || (nbr->capabilities != capabilities)) { 110 if (!nbr->compat) 111 nbr_fsm(nbr, NBR_EVT_1_WAY_RCVD); 112 nbr->gen_id = gen_id; 113 nbr->capabilities = capabilities; 114 115 /* XXX handle nbr change! */ 116 } 117 118 while (len >= sizeof(nbr_id)) { 119 memcpy(&nbr_id, buf, sizeof(nbr_id)); 120 if (nbr_id == iface->addr.s_addr) { 121 /* seen myself */ 122 if (nbr->state < NBR_STA_2_WAY) 123 nbr_fsm(nbr, NBR_EVT_2_WAY_RCVD); 124 break; 125 } 126 buf += sizeof(nbr_id); 127 len -= sizeof(nbr_id); 128 } 129 130 if (len == 0) { 131 nbr_fsm(nbr, NBR_EVT_1_WAY_RCVD); 132 return; 133 } 134 135 /* XXX len correct?? */ 136 137 return; 138 } 139