1 /* $OpenBSD: reply.c,v 1.5 2016/09/02 16:46:29 renato Exp $ */ 2 3 /* 4 * Copyright (c) 2015 Renato Westphal <renato@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 <netinet/in.h> 21 #include <netinet/ip.h> 22 #include <netinet/ip6.h> 23 24 #include <stdlib.h> 25 26 #include "eigrpd.h" 27 #include "eigrpe.h" 28 #include "log.h" 29 30 /* reply packet handling */ 31 32 void 33 send_reply(struct nbr *nbr, struct rinfo_head *rinfo_list, int siareply) 34 { 35 struct eigrp *eigrp = nbr->ei->eigrp; 36 struct ibuf *buf; 37 uint16_t opcode; 38 struct rinfo_entry *re; 39 int size; 40 int route_len; 41 42 if (rinfo_list == NULL || TAILQ_EMPTY(rinfo_list)) 43 return; 44 45 do { 46 if ((buf = ibuf_dynamic(PKG_DEF_SIZE, 47 IP_MAXPACKET - sizeof(struct ip))) == NULL) 48 fatal("send_reply"); 49 50 if (!siareply) 51 opcode = EIGRP_OPC_REPLY; 52 else 53 opcode = EIGRP_OPC_SIAREPLY; 54 55 /* EIGRP header */ 56 if (gen_eigrp_hdr(buf, opcode, 0, eigrp->seq_num, eigrp->as)) 57 goto fail; 58 59 switch (eigrp->af) { 60 case AF_INET: 61 size = sizeof(struct ip); 62 break; 63 case AF_INET6: 64 size = sizeof(struct ip6_hdr); 65 break; 66 default: 67 fatalx("send_reply: unknown af"); 68 } 69 size += sizeof(struct eigrp_hdr); 70 71 while ((re = TAILQ_FIRST(rinfo_list)) != NULL) { 72 route_len = len_route_tlv(&re->rinfo); 73 /* don't exceed the MTU to avoid IP fragmentation */ 74 if (size + route_len > nbr->ei->iface->mtu) { 75 rtp_send_ucast(nbr, buf); 76 break; 77 } 78 size += route_len; 79 80 if (gen_route_tlv(buf, &re->rinfo)) 81 goto fail; 82 TAILQ_REMOVE(rinfo_list, re, entry); 83 free(re); 84 } 85 } while (!TAILQ_EMPTY(rinfo_list)); 86 87 /* reply packets are always unicast */ 88 rtp_send_ucast(nbr, buf); 89 return; 90 fail: 91 log_warnx("%s: failed to send message", __func__); 92 if (rinfo_list) 93 message_list_clr(rinfo_list); 94 ibuf_free(buf); 95 return; 96 } 97 98 void 99 recv_reply(struct nbr *nbr, struct rinfo_head *rinfo_list, int siareply) 100 { 101 int type; 102 struct rinfo_entry *re; 103 104 /* 105 * draft-savage-eigrp-02 - Section 4.3: 106 * "When a REPLY packet is received, there is no reason to process 107 * the packet before an acknowledgment is sent. Therefore, an Ack 108 * packet is sent immediately and then the packet is processed." 109 */ 110 rtp_send_ack(nbr); 111 112 if (!siareply) 113 type = IMSG_RECV_REPLY; 114 else 115 type = IMSG_RECV_SIAREPLY; 116 117 TAILQ_FOREACH(re, rinfo_list, entry) 118 eigrpe_imsg_compose_rde(type, nbr->peerid, 0, &re->rinfo, 119 sizeof(re->rinfo)); 120 } 121