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
send_reply(struct nbr * nbr,struct rinfo_head * rinfo_list,int siareply)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
recv_reply(struct nbr * nbr,struct rinfo_head * rinfo_list,int siareply)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