1 /* $Id: ifacewatch.c,v 1.16 2015/09/03 18:31:25 nanard Exp $ */
2 /* MiniUPnP project
3 * (c) 2011-2018 Thomas Bernard
4 * website : http://miniupnp.free.fr/ or https://miniupnp.tuxfamily.org/
5 * This software is subject to the conditions detailed
6 * in the LICENCE file provided within the distribution */
7 #include "config.h"
8
9 #include <stdlib.h>
10 #include <stdio.h>
11 #include <unistd.h>
12 #include <string.h>
13 #include <sys/types.h>
14 #include <sys/socket.h>
15 #include <netinet/in.h>
16 #include <arpa/inet.h>
17 #include <net/if.h>
18 #ifdef __linux__
19 #include <linux/netlink.h>
20 #include <linux/rtnetlink.h>
21 #else /* __linux__ */
22 #include <net/route.h>
23 #ifdef AF_LINK
24 #include <net/if_dl.h>
25 #endif
26 #endif /* __linux__ */
27 #include <syslog.h>
28 #include <inttypes.h>
29
30 #include "config.h"
31 #include "openssdpsocket.h"
32 #include "upnputils.h"
33 #include "minissdpdtypes.h"
34
35 extern struct lan_addr_list lan_addrs;
36
37 #ifndef __linux__
38 #if defined(__OpenBSD__) || defined(__FreeBSD__)
39 #define SALIGN (sizeof(long) - 1)
40 #else
41 #define SALIGN (sizeof(int32_t) - 1)
42 #endif
43 #define SA_RLEN(sa) (SA_LEN(sa) ? ((SA_LEN(sa) + SALIGN) & ~SALIGN) : (SALIGN + 1))
44 #endif
45
46 int
OpenAndConfInterfaceWatchSocket(void)47 OpenAndConfInterfaceWatchSocket(void)
48 {
49 int s;
50 #ifdef __linux__
51 struct sockaddr_nl addr;
52
53 s = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
54 #else /* __linux__*/
55 /*s = socket(PF_ROUTE, SOCK_RAW, AF_INET);*/
56 s = socket(PF_ROUTE, SOCK_RAW, AF_UNSPEC);
57 /* The family parameter may be AF_UNSPEC which will provide routing informa-
58 * tion for all address families, or can be restricted to a specific address
59 * family by specifying which one is desired. There can be more than one
60 * routing socket open per system. */
61 #endif
62 if(s < 0) {
63 syslog(LOG_ERR, "%s socket: %m",
64 "OpenAndConfInterfaceWatchSocket");
65 return -1;
66 }
67 if(!set_non_blocking(s)) {
68 syslog(LOG_WARNING, "%s failed to set socket non blocking : %m",
69 "OpenAndConfInterfaceWatchSocket");
70 }
71 #ifdef __linux__
72 memset(&addr, 0, sizeof(addr));
73 addr.nl_family = AF_NETLINK;
74 addr.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR | RTMGRP_IPV6_IFADDR;
75
76 if (bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
77 syslog(LOG_ERR, "bind(netlink): %m");
78 close(s);
79 return -1;
80 }
81 #endif
82 return s;
83 }
84
85 /**
86 * Process the message and add/drop multicast membership if needed
87 */
88 int
ProcessInterfaceWatch(int s,int s_ssdp,int s_ssdp6)89 ProcessInterfaceWatch(int s, int s_ssdp, int s_ssdp6)
90 {
91 struct lan_addr_s * lan_addr;
92 ssize_t len;
93 char buffer[4096];
94 #ifdef __linux__
95 struct iovec iov;
96 struct msghdr hdr;
97 struct nlmsghdr *nlhdr;
98 struct ifaddrmsg *ifa;
99 struct rtattr *rta;
100 int ifa_len;
101
102 #ifndef ENABLE_IPV6
103 (void)s_ssdp6;
104 #endif
105 iov.iov_base = buffer;
106 iov.iov_len = sizeof(buffer);
107
108 memset(&hdr, 0, sizeof(hdr));
109 hdr.msg_iov = &iov;
110 hdr.msg_iovlen = 1;
111
112 len = recvmsg(s, &hdr, 0);
113 if(len < 0) {
114 syslog(LOG_ERR, "recvmsg(s, &hdr, 0): %m");
115 return -1;
116 }
117
118 for(nlhdr = (struct nlmsghdr *)buffer;
119 NLMSG_OK(nlhdr, len);
120 nlhdr = NLMSG_NEXT(nlhdr, len)) {
121 int is_del = 0;
122 char address[48];
123 char ifname[IFNAMSIZ];
124 address[0] = '\0';
125 ifname[0] = '\0';
126 if(nlhdr->nlmsg_type == NLMSG_DONE)
127 break;
128 switch(nlhdr->nlmsg_type) {
129 /* case RTM_NEWLINK: */
130 /* case RTM_DELLINK: */
131 case RTM_DELADDR:
132 is_del = 1;
133 case RTM_NEWADDR:
134 /* http://linux-hacks.blogspot.fr/2009/01/sample-code-to-learn-netlink.html */
135 ifa = (struct ifaddrmsg *)NLMSG_DATA(nlhdr);
136 rta = (struct rtattr *)IFA_RTA(ifa);
137 ifa_len = IFA_PAYLOAD(nlhdr);
138 syslog(LOG_DEBUG, "%s %s index=%d fam=%d prefixlen=%d flags=%d scope=%d",
139 "ProcessInterfaceWatchNotify", is_del ? "RTM_DELADDR" : "RTM_NEWADDR",
140 ifa->ifa_index, ifa->ifa_family, ifa->ifa_prefixlen,
141 ifa->ifa_flags, ifa->ifa_scope);
142 for(;RTA_OK(rta, ifa_len); rta = RTA_NEXT(rta, ifa_len)) {
143 /*RTA_DATA(rta)*/
144 /*rta_type : IFA_ADDRESS, IFA_LOCAL, etc. */
145 char tmp[128];
146 memset(tmp, 0, sizeof(tmp));
147 switch(rta->rta_type) {
148 case IFA_ADDRESS:
149 case IFA_LOCAL:
150 case IFA_BROADCAST:
151 case IFA_ANYCAST:
152 inet_ntop(ifa->ifa_family, RTA_DATA(rta), tmp, sizeof(tmp));
153 if(rta->rta_type == IFA_ADDRESS)
154 strncpy(address, tmp, sizeof(address));
155 break;
156 case IFA_LABEL:
157 strncpy(tmp, RTA_DATA(rta), sizeof(tmp));
158 strncpy(ifname, tmp, sizeof(ifname));
159 break;
160 case IFA_CACHEINFO:
161 {
162 struct ifa_cacheinfo *cache_info;
163 cache_info = RTA_DATA(rta);
164 snprintf(tmp, sizeof(tmp), "valid=%u preferred=%u",
165 cache_info->ifa_valid, cache_info->ifa_prefered);
166 }
167 break;
168 default:
169 strncpy(tmp, "*unknown*", sizeof(tmp));
170 }
171 syslog(LOG_DEBUG, " rta_len=%d rta_type=%d '%s'", rta->rta_len, rta->rta_type, tmp);
172 }
173 syslog(LOG_INFO, "%s: %s/%d %s",
174 is_del ? "RTM_DELADDR" : "RTM_NEWADDR",
175 address, ifa->ifa_prefixlen, ifname);
176 for(lan_addr = lan_addrs.lh_first; lan_addr != NULL; lan_addr = lan_addr->list.le_next) {
177 #ifdef ENABLE_IPV6
178 if((0 == strcmp(address, lan_addr->str)) ||
179 (0 == strcmp(ifname, lan_addr->ifname)) ||
180 (ifa->ifa_index == lan_addr->index)) {
181 #else
182 if((0 == strcmp(address, lan_addr->str)) ||
183 (0 == strcmp(ifname, lan_addr->ifname))) {
184 #endif
185 if(ifa->ifa_family == AF_INET)
186 AddDropMulticastMembership(s_ssdp, lan_addr, 0, is_del);
187 #ifdef ENABLE_IPV6
188 else if(ifa->ifa_family == AF_INET6)
189 AddDropMulticastMembership(s_ssdp6, lan_addr, 1, is_del);
190 #endif
191 break;
192 }
193 }
194 break;
195 default:
196 syslog(LOG_DEBUG, "unknown nlmsg_type=%d", nlhdr->nlmsg_type);
197 }
198 }
199 #else /* __linux__ */
200 struct rt_msghdr * rtm;
201 struct ifa_msghdr * ifam;
202 int is_del = 0;
203 char tmp[64];
204 char * p;
205 struct sockaddr * sa;
206 int addr;
207 char address[48];
208 char ifname[IFNAMSIZ];
209 int family = AF_UNSPEC;
210 int prefixlen = 0;
211
212 #ifndef ENABLE_IPV6
213 (void)s_ssdp6;
214 #endif
215 address[0] = '\0';
216 ifname[0] = '\0';
217
218 len = recv(s, buffer, sizeof(buffer), 0);
219 if(len < 0) {
220 syslog(LOG_ERR, "%s recv: %m", "ProcessInterfaceWatchNotify");
221 return -1;
222 }
223 rtm = (struct rt_msghdr *)buffer;
224 switch(rtm->rtm_type) {
225 case RTM_DELADDR:
226 is_del = 1;
227 case RTM_NEWADDR:
228 ifam = (struct ifa_msghdr *)buffer;
229 syslog(LOG_DEBUG, "%s %s len=%d/%hu index=%hu addrs=%x flags=%x",
230 "ProcessInterfaceWatchNotify", is_del?"RTM_DELADDR":"RTM_NEWADDR",
231 (int)len, ifam->ifam_msglen,
232 ifam->ifam_index, ifam->ifam_addrs, ifam->ifam_flags);
233 p = buffer + sizeof(struct ifa_msghdr);
234 addr = 1;
235 while(p < buffer + len) {
236 sa = (struct sockaddr *)p;
237 while(!(addr & ifam->ifam_addrs) && (addr <= ifam->ifam_addrs))
238 addr = addr << 1;
239 sockaddr_to_string(sa, tmp, sizeof(tmp));
240 syslog(LOG_DEBUG, " %s", tmp);
241 switch(addr) {
242 case RTA_DST:
243 case RTA_GATEWAY:
244 break;
245 case RTA_NETMASK:
246 if(sa->sa_family == AF_INET
247 #if defined(__OpenBSD__)
248 || (sa->sa_family == 0 &&
249 sa->sa_len <= sizeof(struct sockaddr_in))
250 #endif
251 ) {
252 uint32_t sin_addr = ntohl(((struct sockaddr_in *)sa)->sin_addr.s_addr);
253 while((prefixlen < 32) &&
254 ((sin_addr & (1 << (31 - prefixlen))) != 0))
255 prefixlen++;
256 } else if(sa->sa_family == AF_INET6
257 #if defined(__OpenBSD__)
258 || (sa->sa_family == 0 &&
259 sa->sa_len == sizeof(struct sockaddr_in6))
260 #endif
261 ) {
262 int i = 0;
263 uint8_t * q = ((struct sockaddr_in6 *)sa)->sin6_addr.s6_addr;
264 while((*q == 0xff) && (i < 16)) {
265 prefixlen += 8;
266 q++; i++;
267 }
268 if(i < 16) {
269 i = 0;
270 while((i < 8) &&
271 ((*q & (1 << (7 - i))) != 0))
272 i++;
273 prefixlen += i;
274 }
275 }
276 break;
277 case RTA_GENMASK:
278 break;
279 case RTA_IFP:
280 #ifdef AF_LINK
281 if(sa->sa_family == AF_LINK) {
282 struct sockaddr_dl * sdl = (struct sockaddr_dl *)sa;
283 memset(ifname, 0, sizeof(ifname));
284 memcpy(ifname, sdl->sdl_data, sdl->sdl_nlen);
285 }
286 #endif
287 break;
288 case RTA_IFA:
289 family = sa->sa_family;
290 if(sa->sa_family == AF_INET) {
291 inet_ntop(sa->sa_family,
292 &((struct sockaddr_in *)sa)->sin_addr,
293 address, sizeof(address));
294 } else if(sa->sa_family == AF_INET6) {
295 inet_ntop(sa->sa_family,
296 &((struct sockaddr_in6 *)sa)->sin6_addr,
297 address, sizeof(address));
298 }
299 break;
300 case RTA_AUTHOR:
301 break;
302 case RTA_BRD:
303 break;
304 }
305 #if 0
306 syslog(LOG_DEBUG, " %d.%d.%d.%d %02x%02x%02x%02x",
307 (uint8_t)p[0], (uint8_t)p[1], (uint8_t)p[2], (uint8_t)p[3],
308 (uint8_t)p[0], (uint8_t)p[1], (uint8_t)p[2], (uint8_t)p[3]);
309 syslog(LOG_DEBUG, " %d.%d.%d.%d %02x%02x%02x%02x",
310 (uint8_t)p[4], (uint8_t)p[5], (uint8_t)p[6], (uint8_t)p[7],
311 (uint8_t)p[4], (uint8_t)p[5], (uint8_t)p[6], (uint8_t)p[7]);
312 #endif
313 p += SA_RLEN(sa);
314 addr = addr << 1;
315 }
316 syslog(LOG_INFO, "%s: %s/%d %s",
317 is_del ? "RTM_DELADDR" : "RTM_NEWADDR",
318 address, prefixlen, ifname);
319 for(lan_addr = lan_addrs.lh_first; lan_addr != NULL; lan_addr = lan_addr->list.le_next) {
320 #ifdef ENABLE_IPV6
321 if((0 == strcmp(address, lan_addr->str)) ||
322 (0 == strcmp(ifname, lan_addr->ifname)) ||
323 (ifam->ifam_index == lan_addr->index)) {
324 #else
325 if((0 == strcmp(address, lan_addr->str)) ||
326 (0 == strcmp(ifname, lan_addr->ifname))) {
327 #endif
328 if(family == AF_INET)
329 AddDropMulticastMembership(s_ssdp, lan_addr, 0, is_del);
330 #ifdef ENABLE_IPV6
331 else if(family == AF_INET6)
332 AddDropMulticastMembership(s_ssdp6, lan_addr, 1, is_del);
333 #endif
334 break;
335 }
336 }
337 break;
338 default:
339 syslog(LOG_DEBUG, "Unknown RTM message : rtm->rtm_type=%d len=%d",
340 rtm->rtm_type, (int)len);
341 }
342 #endif
343 return 0;
344 }
345
346