1 /*
2   PIM for Quagga
3   Copyright (C) 2008  Everton da Silva Marques
4 
5   This program is free software; you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by
7   the Free Software Foundation; either version 2 of the License, or
8   (at your option) any later version.
9 
10   This program is distributed in the hope that it will be useful, but
11   WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13   General Public License for more details.
14 
15   You should have received a copy of the GNU General Public License
16   along with this program; see the file COPYING; if not, write to the
17   Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
18   MA 02110-1301 USA
19 
20   $QuaggaId: $Format:%an, %ai, %h$ $
21 */
22 
23 #include <zebra.h>
24 
25 #include "if.h"
26 #include "log.h"
27 #include "memory.h"
28 
29 #include "pim_ssmpingd.h"
30 #include "pim_time.h"
31 #include "pim_sock.h"
32 #include "pim_str.h"
33 #include "pimd.h"
34 
35 static const char * const PIM_SSMPINGD_REPLY_GROUP = "232.43.211.234";
36 
37 enum {
38   PIM_SSMPINGD_REQUEST = 'Q',
39   PIM_SSMPINGD_REPLY   = 'A'
40 };
41 
42 static void ssmpingd_read_on(struct ssmpingd_sock *ss);
43 
pim_ssmpingd_init()44 void pim_ssmpingd_init()
45 {
46   int result;
47 
48   zassert(!qpim_ssmpingd_list);
49 
50   result = inet_pton(AF_INET, PIM_SSMPINGD_REPLY_GROUP, &qpim_ssmpingd_group_addr);
51 
52   zassert(result > 0);
53 }
54 
pim_ssmpingd_destroy()55 void pim_ssmpingd_destroy()
56 {
57   if (qpim_ssmpingd_list) {
58     list_free(qpim_ssmpingd_list);
59     qpim_ssmpingd_list = 0;
60   }
61 }
62 
ssmpingd_find(struct in_addr source_addr)63 static struct ssmpingd_sock *ssmpingd_find(struct in_addr source_addr)
64 {
65   struct listnode      *node;
66   struct ssmpingd_sock *ss;
67 
68   if (!qpim_ssmpingd_list)
69     return 0;
70 
71   for (ALL_LIST_ELEMENTS_RO(qpim_ssmpingd_list, node, ss))
72     if (source_addr.s_addr == ss->source_addr.s_addr)
73       return ss;
74 
75   return 0;
76 }
77 
ssmpingd_free(struct ssmpingd_sock * ss)78 static void ssmpingd_free(struct ssmpingd_sock *ss)
79 {
80   XFREE(MTYPE_PIM_SSMPINGD, ss);
81 }
82 
ssmpingd_socket(struct in_addr addr,int port,int mttl)83 static int ssmpingd_socket(struct in_addr addr, int port, int mttl)
84 {
85   struct sockaddr_in sockaddr;
86   int fd;
87 
88   fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
89   if (fd < 0) {
90     zlog_err("%s: could not create socket: errno=%d: %s",
91 	     __PRETTY_FUNCTION__, errno, safe_strerror(errno));
92     return -1;
93   }
94 
95   sockaddr.sin_family = AF_INET;
96   sockaddr.sin_addr   = addr;
97   sockaddr.sin_port   = htons(port);
98 
99   if (bind(fd, (struct sockaddr *)&sockaddr, sizeof(sockaddr))) {
100     char addr_str[100];
101     pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
102     zlog_warn("%s: bind(fd=%d,addr=%s,port=%d,len=%zu) failure: errno=%d: %s",
103 	      __PRETTY_FUNCTION__,
104 	      fd, addr_str, port, sizeof(sockaddr),
105 	      errno, safe_strerror(errno));
106     close(fd);
107     return -1;
108   }
109 
110   /* Needed to obtain destination address from recvmsg() */
111   {
112 #if defined(HAVE_IP_PKTINFO)
113     /* Linux and Solaris IP_PKTINFO */
114     int opt = 1;
115     if (setsockopt(fd, IPPROTO_IP, IP_PKTINFO, &opt, sizeof(opt))) {
116       zlog_warn("%s: could not set IP_PKTINFO on socket fd=%d: errno=%d: %s",
117 		__PRETTY_FUNCTION__, fd, errno, safe_strerror(errno));
118     }
119 #elif defined(HAVE_IP_RECVDSTADDR)
120     /* BSD IP_RECVDSTADDR */
121     int opt = 1;
122     if (setsockopt(fd, IPPROTO_IP, IP_RECVDSTADDR, &opt, sizeof(opt))) {
123       zlog_warn("%s: could not set IP_RECVDSTADDR on socket fd=%d: errno=%d: %s",
124 		__PRETTY_FUNCTION__, fd, errno, safe_strerror(errno));
125     }
126 #else
127     zlog_err("%s %s: missing IP_PKTINFO and IP_RECVDSTADDR: unable to get dst addr from recvmsg()",
128 	     __FILE__, __PRETTY_FUNCTION__);
129     close(fd);
130     return -1;
131 #endif
132   }
133 
134   {
135     int reuse = 1;
136     if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR,
137 		   (void *) &reuse, sizeof(reuse))) {
138       zlog_warn("%s: could not set Reuse Address Option on socket fd=%d: errno=%d: %s",
139 		__PRETTY_FUNCTION__, fd, errno, safe_strerror(errno));
140       close(fd);
141       return -1;
142     }
143   }
144 
145   if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_TTL,
146 		 (void *) &mttl, sizeof(mttl))) {
147     zlog_warn("%s: could not set multicast TTL=%d on socket fd=%d: errno=%d: %s",
148 	      __PRETTY_FUNCTION__, mttl, fd, errno, safe_strerror(errno));
149     close(fd);
150     return -1;
151   }
152 
153   {
154     int loop = 0;
155     if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_LOOP,
156 		   (void *) &loop, sizeof(loop))) {
157       zlog_warn("%s: could not %s Multicast Loopback Option on socket fd=%d: errno=%d: %s",
158 		__PRETTY_FUNCTION__,
159 		loop ? "enable" : "disable",
160 		fd, errno, safe_strerror(errno));
161       close(fd);
162       return PIM_SOCK_ERR_LOOP;
163     }
164   }
165 
166   if (setsockopt(fd, IPPROTO_IP, IP_MULTICAST_IF,
167 		 (void *) &addr, sizeof(addr))) {
168     zlog_warn("%s: could not set Outgoing Interface Option on socket fd=%d: errno=%d: %s",
169 	      __PRETTY_FUNCTION__, fd, errno, safe_strerror(errno));
170     close(fd);
171     return -1;
172   }
173 
174   {
175     long flags;
176 
177     flags = fcntl(fd, F_GETFL, 0);
178     if (flags < 0) {
179       zlog_warn("%s: could not get fcntl(F_GETFL,O_NONBLOCK) on socket fd=%d: errno=%d: %s",
180 		__PRETTY_FUNCTION__, fd, errno, safe_strerror(errno));
181       close(fd);
182       return -1;
183     }
184 
185     if (fcntl(fd, F_SETFL, flags | O_NONBLOCK)) {
186       zlog_warn("%s: could not set fcntl(F_SETFL,O_NONBLOCK) on socket fd=%d: errno=%d: %s",
187 		__PRETTY_FUNCTION__, fd, errno, safe_strerror(errno));
188       close(fd);
189       return -1;
190     }
191   }
192 
193   return fd;
194 }
195 
ssmpingd_delete(struct ssmpingd_sock * ss)196 static void ssmpingd_delete(struct ssmpingd_sock *ss)
197 {
198   zassert(ss);
199   zassert(qpim_ssmpingd_list);
200 
201   THREAD_OFF(ss->t_sock_read);
202 
203   if (close(ss->sock_fd)) {
204     int e = errno;
205     char source_str[100];
206     pim_inet4_dump("<src?>", ss->source_addr, source_str, sizeof(source_str));
207     zlog_warn("%s: failure closing ssmpingd sock_fd=%d for source %s: errno=%d: %s",
208 	      __PRETTY_FUNCTION__,
209 	      ss->sock_fd, source_str, e, safe_strerror(e));
210     /* warning only */
211   }
212 
213   listnode_delete(qpim_ssmpingd_list, ss);
214   ssmpingd_free(ss);
215 }
216 
ssmpingd_sendto(struct ssmpingd_sock * ss,const uint8_t * buf,int len,struct sockaddr_in to)217 static void ssmpingd_sendto(struct ssmpingd_sock *ss,
218 			    const uint8_t *buf,
219 			    int len,
220 			    struct sockaddr_in to)
221 {
222   socklen_t tolen = sizeof(to);
223   int sent;
224 
225   sent = sendto(ss->sock_fd, buf, len, MSG_DONTWAIT,
226                 (struct sockaddr *)&to, tolen);
227   if (sent != len) {
228     int e = errno;
229     char to_str[100];
230     pim_inet4_dump("<to?>", to.sin_addr, to_str, sizeof(to_str));
231     if (sent < 0) {
232       zlog_warn("%s: sendto() failure to %s,%d: fd=%d len=%d: errno=%d: %s",
233 		__PRETTY_FUNCTION__,
234 		to_str, ntohs(to.sin_port), ss->sock_fd, len,
235 		e, safe_strerror(e));
236     }
237     else {
238       zlog_warn("%s: sendto() partial to %s,%d: fd=%d len=%d: sent=%d",
239 		__PRETTY_FUNCTION__,
240 		to_str, ntohs(to.sin_port), ss->sock_fd,
241 		len, sent);
242     }
243   }
244 }
245 
ssmpingd_read_msg(struct ssmpingd_sock * ss)246 static int ssmpingd_read_msg(struct ssmpingd_sock *ss)
247 {
248   struct interface *ifp;
249   struct sockaddr_in from;
250   struct sockaddr_in to;
251   socklen_t fromlen = sizeof(from);
252   socklen_t tolen = sizeof(to);
253   ifindex_t ifindex = -1;
254   uint8_t buf[1000];
255   int len;
256 
257   ++ss->requests;
258 
259   len = pim_socket_recvfromto(ss->sock_fd, buf, sizeof(buf),
260 			      &from, &fromlen,
261 			      &to, &tolen,
262 			      &ifindex);
263   if (len < 0) {
264     char source_str[100];
265     pim_inet4_dump("<src?>", ss->source_addr, source_str, sizeof(source_str));
266     zlog_warn("%s: failure receiving ssmping for source %s on fd=%d: errno=%d: %s",
267 	      __PRETTY_FUNCTION__, source_str, ss->sock_fd, errno, safe_strerror(errno));
268     return -1;
269   }
270 
271   ifp = if_lookup_by_index(ifindex);
272 
273   if (buf[0] != PIM_SSMPINGD_REQUEST) {
274     char source_str[100];
275     char from_str[100];
276     char to_str[100];
277     pim_inet4_dump("<src?>", ss->source_addr, source_str, sizeof(source_str));
278     pim_inet4_dump("<from?>", from.sin_addr, from_str, sizeof(from_str));
279     pim_inet4_dump("<to?>", to.sin_addr, to_str, sizeof(to_str));
280     zlog_warn("%s: bad ssmping type=%d from %s,%d to %s,%d on interface %s ifindex=%d fd=%d src=%s",
281 	      __PRETTY_FUNCTION__,
282 	      buf[0],
283 	      from_str, ntohs(from.sin_port),
284 	      to_str, ntohs(to.sin_port),
285 	      ifp ? ifp->name : "<iface?>",
286 	      ifindex, ss->sock_fd,
287 	      source_str);
288     return 0;
289   }
290 
291   if (PIM_DEBUG_SSMPINGD) {
292     char source_str[100];
293     char from_str[100];
294     char to_str[100];
295     pim_inet4_dump("<src?>", ss->source_addr, source_str, sizeof(source_str));
296     pim_inet4_dump("<from?>", from.sin_addr, from_str, sizeof(from_str));
297     pim_inet4_dump("<to?>", to.sin_addr, to_str, sizeof(to_str));
298     zlog_debug("%s: recv ssmping from %s,%d to %s,%d on interface %s ifindex=%d fd=%d src=%s",
299 	       __PRETTY_FUNCTION__,
300 	       from_str, ntohs(from.sin_port),
301 	       to_str, ntohs(to.sin_port),
302 	       ifp ? ifp->name : "<iface?>",
303 	       ifindex, ss->sock_fd,
304 	       source_str);
305   }
306 
307   buf[0] = PIM_SSMPINGD_REPLY;
308 
309   /* unicast reply */
310   ssmpingd_sendto(ss, buf, len, from);
311 
312   /* multicast reply */
313   from.sin_addr = qpim_ssmpingd_group_addr;
314   ssmpingd_sendto(ss, buf, len, from);
315 
316   return 0;
317 }
318 
ssmpingd_sock_read(struct thread * t)319 static int ssmpingd_sock_read(struct thread *t)
320 {
321   struct ssmpingd_sock *ss;
322   int sock_fd;
323   int result;
324 
325   zassert(t);
326 
327   ss = THREAD_ARG(t);
328   zassert(ss);
329 
330   sock_fd = THREAD_FD(t);
331   zassert(sock_fd == ss->sock_fd);
332 
333   result = ssmpingd_read_msg(ss);
334 
335   /* Keep reading */
336   ss->t_sock_read = 0;
337   ssmpingd_read_on(ss);
338 
339   return result;
340 }
341 
ssmpingd_read_on(struct ssmpingd_sock * ss)342 static void ssmpingd_read_on(struct ssmpingd_sock *ss)
343 {
344   zassert(!ss->t_sock_read);
345   THREAD_READ_ON(master, ss->t_sock_read,
346 		 ssmpingd_sock_read, ss, ss->sock_fd);
347 }
348 
ssmpingd_new(struct in_addr source_addr)349 static struct ssmpingd_sock *ssmpingd_new(struct in_addr source_addr)
350 {
351   struct ssmpingd_sock *ss;
352   int sock_fd;
353 
354   if (!qpim_ssmpingd_list) {
355     qpim_ssmpingd_list = list_new();
356     if (!qpim_ssmpingd_list) {
357       zlog_err("%s %s: failure: qpim_ssmpingd_list=list_new()",
358 	       __FILE__, __PRETTY_FUNCTION__);
359       return 0;
360     }
361     qpim_ssmpingd_list->del = (void (*)(void *)) ssmpingd_free;
362   }
363 
364   sock_fd = ssmpingd_socket(source_addr, /* port: */ 4321, /* mTTL: */ 64);
365   if (sock_fd < 0) {
366     char source_str[100];
367     pim_inet4_dump("<src?>", source_addr, source_str, sizeof(source_str));
368     zlog_warn("%s: ssmpingd_socket() failure for source %s",
369 	      __PRETTY_FUNCTION__, source_str);
370     return 0;
371   }
372 
373   ss = XMALLOC(MTYPE_PIM_SSMPINGD, sizeof(*ss));
374   if (!ss) {
375     char source_str[100];
376     pim_inet4_dump("<src?>", source_addr, source_str, sizeof(source_str));
377     zlog_err("%s: XMALLOC(%zu) failure for ssmpingd source %s",
378 	     __PRETTY_FUNCTION__,
379 	     sizeof(*ss), source_str);
380     close(sock_fd);
381     return 0;
382   }
383 
384   ss->sock_fd     = sock_fd;
385   ss->t_sock_read = 0;
386   ss->source_addr = source_addr;
387   ss->creation    = pim_time_monotonic_sec();
388   ss->requests    = 0;
389 
390   listnode_add(qpim_ssmpingd_list, ss);
391 
392   ssmpingd_read_on(ss);
393 
394   return ss;
395 }
396 
pim_ssmpingd_start(struct in_addr source_addr)397 int pim_ssmpingd_start(struct in_addr source_addr)
398 {
399   struct ssmpingd_sock *ss;
400 
401   ss = ssmpingd_find(source_addr);
402   if (ss) {
403     /* silently ignore request to recreate entry */
404     return 0;
405   }
406 
407   {
408     char source_str[100];
409     pim_inet4_dump("<src?>", source_addr, source_str, sizeof(source_str));
410     zlog_info("%s: starting ssmpingd for source %s",
411 	      __PRETTY_FUNCTION__, source_str);
412   }
413 
414   ss = ssmpingd_new(source_addr);
415   if (!ss) {
416     char source_str[100];
417     pim_inet4_dump("<src?>", source_addr, source_str, sizeof(source_str));
418     zlog_warn("%s: ssmpingd_new() failure for source %s",
419 	      __PRETTY_FUNCTION__, source_str);
420     return -1;
421   }
422 
423   return 0;
424 }
425 
pim_ssmpingd_stop(struct in_addr source_addr)426 int pim_ssmpingd_stop(struct in_addr source_addr)
427 {
428   struct ssmpingd_sock *ss;
429 
430   ss = ssmpingd_find(source_addr);
431   if (!ss) {
432     char source_str[100];
433     pim_inet4_dump("<src?>", source_addr, source_str, sizeof(source_str));
434     zlog_warn("%s: could not find ssmpingd for source %s",
435 	      __PRETTY_FUNCTION__, source_str);
436     return -1;
437   }
438 
439   {
440     char source_str[100];
441     pim_inet4_dump("<src?>", source_addr, source_str, sizeof(source_str));
442     zlog_info("%s: stopping ssmpingd for source %s",
443 	      __PRETTY_FUNCTION__, source_str);
444   }
445 
446   ssmpingd_delete(ss);
447 
448   return 0;
449 }
450