1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
|
/*
* BIRD Internet Routing Daemon -- Linux Multicasting and Network Includes
*
* (c) 1998--2000 Martin Mares <mj@ucw.cz>
*
* Can be freely distributed and used under the terms of the GNU GPL.
*/
#include <net/if.h>
#ifdef IPV6
#ifndef IPV6_UNICAST_HOPS
/* Needed on glibc 2.0 systems */
#include <linux/in6.h>
#define CONFIG_IPV6_GLIBC_20
#endif
static inline void
set_inaddr(struct in6_addr *ia, ip_addr a)
{
ipa_hton(a);
memcpy(ia, &a, sizeof(a));
}
static inline void
get_inaddr(ip_addr *a, struct in6_addr *ia)
{
memcpy(a, ia, sizeof(*a));
ipa_ntoh(*a);
}
static inline char *
sysio_bind_to_iface(sock *s)
{
struct ifreq ifr;
strcpy(ifr.ifr_name, s->iface->name);
if (setsockopt(s->fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) < 0)
return "SO_BINDTODEVICE";
return NULL;
}
#else
static inline void
set_inaddr(struct in_addr *ia, ip_addr a)
{
ipa_hton(a);
memcpy(&ia->s_addr, &a, sizeof(a));
}
static inline void
get_inaddr(ip_addr *a, struct in_addr *ia)
{
memcpy(a, &ia->s_addr, sizeof(*a));
ipa_ntoh(*a);
}
/*
* Multicasting in Linux systems is a real mess. Not only different kernels
* have different interfaces, but also different libc's export it in different
* ways. Horrible.
*/
#if defined(CONFIG_LINUX_MC_MREQ) || defined(CONFIG_LINUX_MC_MREQ_BIND)
/*
* Older kernels support only struct mreq which matches interfaces by their
* addresses and thus fails on unnumbered devices. On newer 2.0 kernels
* we can use SO_BINDTODEVICE to circumvent this problem.
*/
#define MREQ_IFA struct in_addr
#define MREQ_GRP struct ip_mreq
static inline void fill_mreq_ifa(struct in_addr *m, struct iface *ifa UNUSED, ip_addr saddr, ip_addr maddr UNUSED)
{
set_inaddr(m, saddr);
}
static inline void fill_mreq_grp(struct ip_mreq *m, struct iface *ifa, ip_addr saddr, ip_addr maddr)
{
bzero(m, sizeof(*m));
#ifdef CONFIG_LINUX_MC_MREQ_BIND
m->imr_interface.s_addr = INADDR_ANY;
#else
set_inaddr(&m->imr_interface, saddr);
#endif
set_inaddr(&m->imr_multiaddr, maddr);
}
#endif
#ifdef CONFIG_LINUX_MC_MREQN
/*
* 2.1 and newer kernels use struct mreqn which passes ifindex, so no
* problems with unnumbered devices.
*/
#ifndef HAVE_STRUCT_IP_MREQN
/* Several versions of glibc don't define this structure, so we have to do it ourselves */
struct ip_mreqn
{
struct in_addr imr_multiaddr; /* IP multicast address of group */
struct in_addr imr_address; /* local IP address of interface */
int imr_ifindex; /* Interface index */
};
#endif
#define MREQ_IFA struct ip_mreqn
#define MREQ_GRP struct ip_mreqn
#define fill_mreq_ifa fill_mreq
#define fill_mreq_grp fill_mreq
static inline void fill_mreq(struct ip_mreqn *m, struct iface *ifa, ip_addr saddr, ip_addr maddr)
{
bzero(m, sizeof(*m));
m->imr_ifindex = ifa->index;
set_inaddr(&m->imr_address, saddr);
set_inaddr(&m->imr_multiaddr, maddr);
}
#endif
static inline char *
sysio_setup_multicast(sock *s)
{
MREQ_IFA m;
int zero = 0;
if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_LOOP, &zero, sizeof(zero)) < 0)
return "IP_MULTICAST_LOOP";
if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_TTL, &s->ttl, sizeof(s->ttl)) < 0)
return "IP_MULTICAST_TTL";
/* This defines where should we send _outgoing_ multicasts */
fill_mreq_ifa(&m, s->iface, s->saddr, IPA_NONE);
if (setsockopt(s->fd, SOL_IP, IP_MULTICAST_IF, &m, sizeof(m)) < 0)
return "IP_MULTICAST_IF";
#if defined(CONFIG_LINUX_MC_MREQ_BIND) || defined(CONFIG_LINUX_MC_MREQN)
{
struct ifreq ifr;
strcpy(ifr.ifr_name, s->iface->name);
if (setsockopt(s->fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) < 0)
return "SO_BINDTODEVICE";
}
#endif
return NULL;
}
static inline char *
sysio_join_group(sock *s, ip_addr maddr)
{
MREQ_GRP m;
/* And this one sets interface for _receiving_ multicasts from */
fill_mreq_grp(&m, s->iface, s->saddr, maddr);
if (setsockopt(s->fd, SOL_IP, IP_ADD_MEMBERSHIP, &m, sizeof(m)) < 0)
return "IP_ADD_MEMBERSHIP";
return NULL;
}
static inline char *
sysio_leave_group(sock *s, ip_addr maddr)
{
MREQ_GRP m;
/* And this one sets interface for _receiving_ multicasts from */
fill_mreq_grp(&m, s->iface, s->saddr, maddr);
if (setsockopt(s->fd, SOL_IP, IP_DROP_MEMBERSHIP, &m, sizeof(m)) < 0)
return "IP_DROP_MEMBERSHIP";
return NULL;
}
#endif
#include <linux/socket.h>
#include <linux/tcp.h>
/* For the case that we have older kernel headers */
/* Copied from Linux kernel file include/linux/tcp.h */
#ifndef TCP_MD5SIG
#define TCP_MD5SIG 14
#define TCP_MD5SIG_MAXKEYLEN 80
struct tcp_md5sig {
struct sockaddr_storage tcpm_addr; /* address associated */
__u16 __tcpm_pad1; /* zero */
__u16 tcpm_keylen; /* key length */
__u32 __tcpm_pad2; /* zero */
__u8 tcpm_key[TCP_MD5SIG_MAXKEYLEN]; /* key (binary) */
};
#endif
static int
sk_set_md5_auth_int(sock *s, sockaddr *sa, char *passwd)
{
struct tcp_md5sig md5;
memset(&md5, 0, sizeof(md5));
memcpy(&md5.tcpm_addr, (struct sockaddr *) sa, sizeof(*sa));
if (passwd)
{
int len = strlen(passwd);
if (len > TCP_MD5SIG_MAXKEYLEN)
{
log(L_ERR "MD5 password too long");
return -1;
}
md5.tcpm_keylen = len;
memcpy(&md5.tcpm_key, passwd, len);
}
int rv = setsockopt(s->fd, IPPROTO_TCP, TCP_MD5SIG, &md5, sizeof(md5));
if (rv < 0)
{
if (errno == ENOPROTOOPT)
log(L_ERR "Kernel does not support TCP MD5 signatures");
else
log(L_ERR "sk_set_md5_auth_int: setsockopt: %m");
}
return rv;
}
#ifndef IPV6
/* RX/TX packet info handling for IPv4 */
/* Mostly similar to standardized IPv6 code */
#define CMSG_RX_SPACE CMSG_SPACE(sizeof(struct in_pktinfo))
#define CMSG_TX_SPACE CMSG_SPACE(sizeof(struct in_pktinfo))
static char *
sysio_register_cmsgs(sock *s)
{
int ok = 1;
if ((s->flags & SKF_LADDR_RX) &&
setsockopt(s->fd, IPPROTO_IP, IP_PKTINFO, &ok, sizeof(ok)) < 0)
return "IP_PKTINFO";
return NULL;
}
static void
sysio_process_rx_cmsgs(sock *s, struct msghdr *msg)
{
struct cmsghdr *cm;
struct in_pktinfo *pi = NULL;
if (!(s->flags & SKF_LADDR_RX))
return;
for (cm = CMSG_FIRSTHDR(msg); cm != NULL; cm = CMSG_NXTHDR(msg, cm))
{
if (cm->cmsg_level == IPPROTO_IP && cm->cmsg_type == IP_PKTINFO)
pi = (struct in_pktinfo *) CMSG_DATA(cm);
}
if (!pi)
{
s->laddr = IPA_NONE;
s->lifindex = 0;
return;
}
get_inaddr(&s->laddr, &pi->ipi_addr);
s->lifindex = pi->ipi_ifindex;
return;
}
static void
sysio_prepare_tx_cmsgs(sock *s, struct msghdr *msg, void *cbuf, size_t cbuflen)
{
struct cmsghdr *cm;
struct in_pktinfo *pi;
if (!(s->flags & SKF_LADDR_TX))
return;
msg->msg_control = cbuf;
msg->msg_controllen = cbuflen;
cm = CMSG_FIRSTHDR(msg);
cm->cmsg_level = IPPROTO_IP;
cm->cmsg_type = IP_PKTINFO;
cm->cmsg_len = CMSG_LEN(sizeof(*pi));
pi = (struct in_pktinfo *) CMSG_DATA(cm);
set_inaddr(&pi->ipi_spec_dst, s->saddr);
pi->ipi_ifindex = s->iface ? s->iface->index : 0;
msg->msg_controllen = cm->cmsg_len;
}
#endif
|