1 /*
2 * BIRD Internet Routing Daemon -- Linux Multicasting and Network Includes
3 *
4 * (c) 1998--2000 Martin Mares <mj@ucw.cz>
5 *
6 * Can be freely distributed and used under the terms of the GNU GPL.
7 */
8
9 #ifndef IPV6_MINHOPCOUNT
10 #define IPV6_MINHOPCOUNT 73
11 #endif
12
13 #ifndef TCP_MD5SIG_EXT
14 #define TCP_MD5SIG_EXT 32
15 #endif
16
17 #ifndef TCP_MD5SIG_FLAG_PREFIX
18 #define TCP_MD5SIG_FLAG_PREFIX 1
19 #endif
20
21 /* We redefine the tcp_md5sig structure with different name to avoid collision with older headers */
22 struct tcp_md5sig_ext {
23 struct sockaddr_storage tcpm_addr; /* Address associated */
24 u8 tcpm_flags; /* Extension flags */
25 u8 tcpm_prefixlen; /* Address prefix */
26 u16 tcpm_keylen; /* Key length */
27 u32 __tcpm_pad2; /* Zero */
28 u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* Key (binary) */
29 };
30
31
32 /* Linux does not care if sa_len is larger than needed */
33 #define SA_LEN(x) sizeof(sockaddr)
34
35
36 /*
37 * Linux IPv4 multicast syscalls
38 */
39
40 #define INIT_MREQ4(maddr,ifa) \
41 { .imr_multiaddr = ipa_to_in4(maddr), .imr_ifindex = ifa->index }
42
43 static inline int
sk_setup_multicast4(sock * s)44 sk_setup_multicast4(sock *s)
45 {
46 struct ip_mreqn mr = { .imr_ifindex = s->iface->index };
47 int ttl = s->ttl;
48 int n = 0;
49
50 /* This defines where should we send _outgoing_ multicasts */
51 if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_IF, &mr, sizeof(mr)) < 0)
52 ERR("IP_MULTICAST_IF");
53
54 if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
55 ERR("IP_MULTICAST_TTL");
56
57 if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_LOOP, &n, sizeof(n)) < 0)
58 ERR("IP_MULTICAST_LOOP");
59
60 return 0;
61 }
62
63 static inline int
sk_join_group4(sock * s,ip_addr maddr)64 sk_join_group4(sock *s, ip_addr maddr)
65 {
66 struct ip_mreqn mr = INIT_MREQ4(maddr, s->iface);
67
68 if (setsockopt(s->fd, SOL_IP, IP_ADD_MEMBERSHIP, &mr, sizeof(mr)) < 0)
69 ERR("IP_ADD_MEMBERSHIP");
70
71 return 0;
72 }
73
74 static inline int
sk_leave_group4(sock * s,ip_addr maddr)75 sk_leave_group4(sock *s, ip_addr maddr)
76 {
77 struct ip_mreqn mr = INIT_MREQ4(maddr, s->iface);
78
79 if (setsockopt(s->fd, SOL_IP, IP_DROP_MEMBERSHIP, &mr, sizeof(mr)) < 0)
80 ERR("IP_DROP_MEMBERSHIP");
81
82 return 0;
83 }
84
85
86 /*
87 * Linux IPv4 packet control messages
88 */
89
90 /* Mostly similar to standardized IPv6 code */
91
92 #define CMSG4_SPACE_PKTINFO CMSG_SPACE(sizeof(struct in_pktinfo))
93 #define CMSG4_SPACE_TTL CMSG_SPACE(sizeof(int))
94
95 static inline int
sk_request_cmsg4_pktinfo(sock * s)96 sk_request_cmsg4_pktinfo(sock *s)
97 {
98 int y = 1;
99
100 if (setsockopt(s->fd, SOL_IP, IP_PKTINFO, &y, sizeof(y)) < 0)
101 ERR("IP_PKTINFO");
102
103 return 0;
104 }
105
106 static inline int
sk_request_cmsg4_ttl(sock * s)107 sk_request_cmsg4_ttl(sock *s)
108 {
109 int y = 1;
110
111 if (setsockopt(s->fd, SOL_IP, IP_RECVTTL, &y, sizeof(y)) < 0)
112 ERR("IP_RECVTTL");
113
114 return 0;
115 }
116
117 static inline void
sk_process_cmsg4_pktinfo(sock * s,struct cmsghdr * cm)118 sk_process_cmsg4_pktinfo(sock *s, struct cmsghdr *cm)
119 {
120 if (cm->cmsg_type == IP_PKTINFO)
121 {
122 struct in_pktinfo *pi = (struct in_pktinfo *) CMSG_DATA(cm);
123 s->laddr = ipa_from_in4(pi->ipi_addr);
124 s->lifindex = pi->ipi_ifindex;
125 }
126 }
127
128 static inline void
sk_process_cmsg4_ttl(sock * s,struct cmsghdr * cm)129 sk_process_cmsg4_ttl(sock *s, struct cmsghdr *cm)
130 {
131 if (cm->cmsg_type == IP_TTL)
132 s->rcv_ttl = * (int *) CMSG_DATA(cm);
133 }
134
135 static inline void
sk_prepare_cmsgs4(sock * s,struct msghdr * msg,void * cbuf,size_t cbuflen)136 sk_prepare_cmsgs4(sock *s, struct msghdr *msg, void *cbuf, size_t cbuflen)
137 {
138 struct cmsghdr *cm;
139 struct in_pktinfo *pi;
140 int controllen = 0;
141
142 msg->msg_control = cbuf;
143 msg->msg_controllen = cbuflen;
144
145 cm = CMSG_FIRSTHDR(msg);
146 cm->cmsg_level = SOL_IP;
147 cm->cmsg_type = IP_PKTINFO;
148 cm->cmsg_len = CMSG_LEN(sizeof(*pi));
149 controllen += CMSG_SPACE(sizeof(*pi));
150
151 pi = (struct in_pktinfo *) CMSG_DATA(cm);
152 pi->ipi_ifindex = s->iface ? s->iface->index : 0;
153 pi->ipi_spec_dst = ipa_to_in4(s->saddr);
154 pi->ipi_addr = ipa_to_in4(IPA_NONE);
155
156 msg->msg_controllen = controllen;
157 }
158
159
160 /*
161 * Miscellaneous Linux socket syscalls
162 */
163
164 int
sk_set_md5_auth(sock * s,ip_addr local UNUSED,ip_addr remote,int pxlen,struct iface * ifa,const char * passwd,int setkey UNUSED)165 sk_set_md5_auth(sock *s, ip_addr local UNUSED, ip_addr remote, int pxlen, struct iface *ifa, const char *passwd, int setkey UNUSED)
166 {
167 struct tcp_md5sig_ext md5;
168
169 memset(&md5, 0, sizeof(md5));
170 sockaddr_fill((sockaddr *) &md5.tcpm_addr, s->af, remote, ifa, 0);
171
172 if (passwd)
173 {
174 int len = strlen(passwd);
175
176 if (len > TCP_MD5SIG_MAXKEYLEN)
177 ERR_MSG("The password for TCP MD5 Signature is too long");
178
179 md5.tcpm_keylen = len;
180 memcpy(&md5.tcpm_key, passwd, len);
181 }
182
183 if (pxlen < 0)
184 {
185 if (setsockopt(s->fd, SOL_TCP, TCP_MD5SIG, &md5, sizeof(md5)) < 0)
186 if (errno == ENOPROTOOPT)
187 ERR_MSG("Kernel does not support TCP MD5 signatures");
188 else
189 ERR("TCP_MD5SIG");
190 }
191 else
192 {
193 md5.tcpm_flags = TCP_MD5SIG_FLAG_PREFIX;
194 md5.tcpm_prefixlen = pxlen;
195
196 if (setsockopt(s->fd, SOL_TCP, TCP_MD5SIG_EXT, &md5, sizeof(md5)) < 0)
197 {
198 if (errno == ENOPROTOOPT)
199 ERR_MSG("Kernel does not support extended TCP MD5 signatures");
200 else
201 ERR("TCP_MD5SIG_EXT");
202 }
203 }
204
205 return 0;
206 }
207
208 static inline int
sk_set_min_ttl4(sock * s,int ttl)209 sk_set_min_ttl4(sock *s, int ttl)
210 {
211 if (setsockopt(s->fd, SOL_IP, IP_MINTTL, &ttl, sizeof(ttl)) < 0)
212 {
213 if (errno == ENOPROTOOPT)
214 ERR_MSG("Kernel does not support IPv4 TTL security");
215 else
216 ERR("IP_MINTTL");
217 }
218
219 return 0;
220 }
221
222 static inline int
sk_set_min_ttl6(sock * s,int ttl)223 sk_set_min_ttl6(sock *s, int ttl)
224 {
225 if (setsockopt(s->fd, SOL_IPV6, IPV6_MINHOPCOUNT, &ttl, sizeof(ttl)) < 0)
226 {
227 if (errno == ENOPROTOOPT)
228 ERR_MSG("Kernel does not support IPv6 TTL security");
229 else
230 ERR("IPV6_MINHOPCOUNT");
231 }
232
233 return 0;
234 }
235
236 static inline int
sk_disable_mtu_disc4(sock * s)237 sk_disable_mtu_disc4(sock *s)
238 {
239 int dont = IP_PMTUDISC_DONT;
240
241 if (setsockopt(s->fd, SOL_IP, IP_MTU_DISCOVER, &dont, sizeof(dont)) < 0)
242 ERR("IP_MTU_DISCOVER");
243
244 return 0;
245 }
246
247 static inline int
sk_disable_mtu_disc6(sock * s)248 sk_disable_mtu_disc6(sock *s)
249 {
250 int dont = IPV6_PMTUDISC_DONT;
251
252 if (setsockopt(s->fd, SOL_IPV6, IPV6_MTU_DISCOVER, &dont, sizeof(dont)) < 0)
253 ERR("IPV6_MTU_DISCOVER");
254
255 return 0;
256 }
257
258 int sk_priority_control = 7;
259
260 static inline int
sk_set_priority(sock * s,int prio)261 sk_set_priority(sock *s, int prio)
262 {
263 if (setsockopt(s->fd, SOL_SOCKET, SO_PRIORITY, &prio, sizeof(prio)) < 0)
264 ERR("SO_PRIORITY");
265
266 return 0;
267 }
268
269