1 /*
2 * The mrouted program is covered by the license in the accompanying file
3 * named "LICENSE". Use of the mrouted program represents acceptance of
4 * the terms and conditions listed in that file.
5 *
6 * The mrouted program is COPYRIGHT 1989 by The Board of Trustees of
7 * Leland Stanford Junior University.
8 */
9
10 #include "defs.h"
11
12 /*
13 * Exported variables.
14 */
15 #ifdef notyet
16 int raw_socket; /* socket for raw network I/O */
17 #endif
18 /*
19 *XXX For now, we just use the IGMP socket to send packets.
20 * This is legal in BSD, because the protocol # is not checked
21 * on raw sockets. The k_* interfaces need to gain a socket
22 * argument so that we can call them on the raw_socket also.
23 */
24 #define raw_socket igmp_socket
25
26 /*
27 * Private variables.
28 */
29 static int rawid = 0;
30
31 /*
32 * Open and initialize the raw socket.
33 */
init_ipip(void)34 void init_ipip(void)
35 {
36 #ifdef notyet
37 if ((raw_socket = socket(AF_INET, SOCK_RAW, IPPROTO_RAW)) < 0)
38 logit(LOG_ERR, errno, "Raw IP socket");
39 #endif
40 }
41
42 /*
43 * Allocate and fill in static IP header for encapsulating on a tunnel.
44 */
init_ipip_on_vif(struct uvif * v)45 void init_ipip_on_vif(struct uvif *v)
46 {
47 struct ip *ip;
48
49 ip = v->uv_encap_hdr = (struct ip *)malloc(sizeof(struct ip));
50 if (!ip) {
51 logit(LOG_ERR, errno, "Out of memory when setting up IPIP tunnel");
52 return; /* Never reached */
53 }
54
55 /*
56 * Fields zeroed that aren't filled in later:
57 * - IP ID (let the kernel fill it in)
58 * - Offset (we don't send fragments)
59 * - Checksum (let the kernel fill it in)
60 */
61 memset(ip, 0, sizeof(struct ip));
62 ip->ip_v = IPVERSION;
63 ip->ip_hl = sizeof(struct ip) >> 2;
64 ip->ip_tos = 0xc0; /* Internet Control */
65 ip->ip_ttl = MAXTTL; /* applies to unicasts only */
66 ip->ip_p = IPPROTO_IPIP;
67 ip->ip_src.s_addr = v->uv_lcl_addr;
68 ip->ip_dst.s_addr = v->uv_rmt_addr;
69 }
70
71 /*
72 * Call build_igmp() to build an IGMP message in the output packet buffer.
73 * Then fill in the fields of the IP packet that build_igmp() left for the
74 * kernel to fill in, and encapsulate the original packet with the
75 * pre-created ip header for this vif.
76 */
send_ipip(uint32_t src,uint32_t dst,int type,int code,uint32_t group,int datalen,struct uvif * v)77 void send_ipip(uint32_t src, uint32_t dst, int type, int code, uint32_t group, int datalen, struct uvif *v)
78 {
79 struct msghdr msg;
80 struct iovec iov[2];
81 struct sockaddr_in sdst;
82 struct ip *ip;
83
84 build_igmp(src, dst, type, code, group, datalen);
85 ip = (struct ip *)send_buf;
86 ip->ip_id = htons(rawid++);
87 ip->ip_sum = 0;
88 ip->ip_sum = inet_cksum((uint16_t *)ip, ip->ip_hl << 2);
89
90 ip = v->uv_encap_hdr;
91 ip->ip_len = 2 * MIN_IP_HEADER_LEN + IGMP_MINLEN + datalen;
92 #ifndef HAVE_IP_HDRINCL_BSD_ORDER
93 ip->ip_len = htons(ip->ip_len);
94 #endif
95
96 memset(&sdst, 0, sizeof(sdst));
97 sdst.sin_family = AF_INET;
98 #ifdef HAVE_SA_LEN
99 sdst.sin_len = sizeof(sdst);
100 #endif
101 sdst.sin_addr = ip->ip_dst;
102
103 iov[0].iov_base = (caddr_t)v->uv_encap_hdr;
104 iov[0].iov_len = sizeof(struct ip);
105 iov[1].iov_base = (caddr_t)send_buf;
106 iov[1].iov_len = MIN_IP_HEADER_LEN + IGMP_MINLEN + datalen;
107
108 memset(&msg, 0, sizeof(msg));
109 msg.msg_name = (caddr_t)&sdst;
110 msg.msg_namelen = sizeof(sdst);
111 msg.msg_iov = iov;
112 msg.msg_iovlen = 2;
113 if (sendmsg(raw_socket, &msg, 0) < 0) {
114 if (errno == ENETDOWN)
115 check_vif_state();
116 else
117 logit(LOG_WARNING, errno,
118 "sendmsg to %s on %s",
119 inet_fmt(sdst.sin_addr.s_addr, s1, sizeof(s1)), inet_fmt(src, s2, sizeof(s2)));
120 }
121
122 IF_DEBUG(DEBUG_PKT|igmp_debug_kind(type, code))
123 logit(LOG_DEBUG, 0, "SENT %s from %-15s to %s encaped to %s",
124 igmp_packet_kind(type, code), src == INADDR_ANY ? "INADDR_ANY" :
125 inet_fmt(src, s1, sizeof(s1)), inet_fmt(dst, s2, sizeof(s2)),
126 inet_fmt(sdst.sin_addr.s_addr, s3, sizeof(s3)));
127 }
128
129 /**
130 * Local Variables:
131 * version-control: t
132 * indent-tabs-mode: t
133 * c-file-style: "ellemtel"
134 * c-basic-offset: 4
135 * End:
136 */
137