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
35static const char * const PIM_SSMPINGD_REPLY_GROUP = "232.43.211.234";
36
37enum {
38  PIM_SSMPINGD_REQUEST = 'Q',
39  PIM_SSMPINGD_REPLY   = 'A'
40};
41
42static void ssmpingd_read_on(struct ssmpingd_sock *ss);
43
44void 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
55void pim_ssmpingd_destroy()
56{
57  if (qpim_ssmpingd_list) {
58    list_free(qpim_ssmpingd_list);
59    qpim_ssmpingd_list = 0;
60  }
61}
62
63static 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
78static void ssmpingd_free(struct ssmpingd_sock *ss)
79{
80  XFREE(MTYPE_PIM_SSMPINGD, ss);
81}
82
83static 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, &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 IP_PKTINFO */
114    int opt = 1;
115    if (setsockopt(fd, SOL_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
196static 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
217static 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, &to, tolen);
226  if (sent != len) {
227    int e = errno;
228    char to_str[100];
229    pim_inet4_dump("<to?>", to.sin_addr, to_str, sizeof(to_str));
230    if (sent < 0) {
231      zlog_warn("%s: sendto() failure to %s,%d: fd=%d len=%d: errno=%d: %s",
232		__PRETTY_FUNCTION__,
233		to_str, ntohs(to.sin_port), ss->sock_fd, len,
234		e, safe_strerror(e));
235    }
236    else {
237      zlog_warn("%s: sendto() partial to %s,%d: fd=%d len=%d: sent=%d",
238		__PRETTY_FUNCTION__,
239		to_str, ntohs(to.sin_port), ss->sock_fd,
240		len, sent);
241    }
242  }
243}
244
245static int ssmpingd_read_msg(struct ssmpingd_sock *ss)
246{
247  struct interface *ifp;
248  struct sockaddr_in from;
249  struct sockaddr_in to;
250  socklen_t fromlen = sizeof(from);
251  socklen_t tolen = sizeof(to);
252  int ifindex = -1;
253  uint8_t buf[1000];
254  int len;
255
256  ++ss->requests;
257
258  len = pim_socket_recvfromto(ss->sock_fd, buf, sizeof(buf),
259			      &from, &fromlen,
260			      &to, &tolen,
261			      &ifindex);
262  if (len < 0) {
263    char source_str[100];
264    pim_inet4_dump("<src?>", ss->source_addr, source_str, sizeof(source_str));
265    zlog_warn("%s: failure receiving ssmping for source %s on fd=%d: errno=%d: %s",
266	      __PRETTY_FUNCTION__, source_str, ss->sock_fd, errno, safe_strerror(errno));
267    return -1;
268  }
269
270  ifp = if_lookup_by_index(ifindex);
271
272  if (buf[0] != PIM_SSMPINGD_REQUEST) {
273    char source_str[100];
274    char from_str[100];
275    char to_str[100];
276    pim_inet4_dump("<src?>", ss->source_addr, source_str, sizeof(source_str));
277    pim_inet4_dump("<from?>", from.sin_addr, from_str, sizeof(from_str));
278    pim_inet4_dump("<to?>", to.sin_addr, to_str, sizeof(to_str));
279    zlog_warn("%s: bad ssmping type=%d from %s,%d to %s,%d on interface %s ifindex=%d fd=%d src=%s",
280	      __PRETTY_FUNCTION__,
281	      buf[0],
282	      from_str, ntohs(from.sin_port),
283	      to_str, ntohs(to.sin_port),
284	      ifp ? ifp->name : "<iface?>",
285	      ifindex, ss->sock_fd,
286	      source_str);
287    return 0;
288  }
289
290  if (PIM_DEBUG_SSMPINGD) {
291    char source_str[100];
292    char from_str[100];
293    char to_str[100];
294    pim_inet4_dump("<src?>", ss->source_addr, source_str, sizeof(source_str));
295    pim_inet4_dump("<from?>", from.sin_addr, from_str, sizeof(from_str));
296    pim_inet4_dump("<to?>", to.sin_addr, to_str, sizeof(to_str));
297    zlog_debug("%s: recv ssmping from %s,%d to %s,%d on interface %s ifindex=%d fd=%d src=%s",
298	       __PRETTY_FUNCTION__,
299	       from_str, ntohs(from.sin_port),
300	       to_str, ntohs(to.sin_port),
301	       ifp ? ifp->name : "<iface?>",
302	       ifindex, ss->sock_fd,
303	       source_str);
304  }
305
306  buf[0] = PIM_SSMPINGD_REPLY;
307
308  /* unicast reply */
309  ssmpingd_sendto(ss, buf, len, from);
310
311  /* multicast reply */
312  from.sin_addr = qpim_ssmpingd_group_addr;
313  ssmpingd_sendto(ss, buf, len, from);
314
315  return 0;
316}
317
318static int ssmpingd_sock_read(struct thread *t)
319{
320  struct ssmpingd_sock *ss;
321  int sock_fd;
322  int result;
323
324  zassert(t);
325
326  ss = THREAD_ARG(t);
327  zassert(ss);
328
329  sock_fd = THREAD_FD(t);
330  zassert(sock_fd == ss->sock_fd);
331
332  result = ssmpingd_read_msg(ss);
333
334  /* Keep reading */
335  ss->t_sock_read = 0;
336  ssmpingd_read_on(ss);
337
338  return result;
339}
340
341static void ssmpingd_read_on(struct ssmpingd_sock *ss)
342{
343  zassert(!ss->t_sock_read);
344  THREAD_READ_ON(master, ss->t_sock_read,
345		 ssmpingd_sock_read, ss, ss->sock_fd);
346}
347
348static struct ssmpingd_sock *ssmpingd_new(struct in_addr source_addr)
349{
350  struct ssmpingd_sock *ss;
351  int sock_fd;
352
353  if (!qpim_ssmpingd_list) {
354    qpim_ssmpingd_list = list_new();
355    if (!qpim_ssmpingd_list) {
356      zlog_err("%s %s: failure: qpim_ssmpingd_list=list_new()",
357	       __FILE__, __PRETTY_FUNCTION__);
358      return 0;
359    }
360    qpim_ssmpingd_list->del = (void (*)(void *)) ssmpingd_free;
361  }
362
363  sock_fd = ssmpingd_socket(source_addr, /* port: */ 4321, /* mTTL: */ 64);
364  if (sock_fd < 0) {
365    char source_str[100];
366    pim_inet4_dump("<src?>", source_addr, source_str, sizeof(source_str));
367    zlog_warn("%s: ssmpingd_socket() failure for source %s",
368	      __PRETTY_FUNCTION__, source_str);
369    return 0;
370  }
371
372  ss = XMALLOC(MTYPE_PIM_SSMPINGD, sizeof(*ss));
373  if (!ss) {
374    char source_str[100];
375    pim_inet4_dump("<src?>", source_addr, source_str, sizeof(source_str));
376    zlog_err("%s: XMALLOC(%zu) failure for ssmpingd source %s",
377	     __PRETTY_FUNCTION__,
378	     sizeof(*ss), source_str);
379    close(sock_fd);
380    return 0;
381  }
382
383  ss->sock_fd     = sock_fd;
384  ss->t_sock_read = 0;
385  ss->source_addr = source_addr;
386  ss->creation    = pim_time_monotonic_sec();
387  ss->requests    = 0;
388
389  listnode_add(qpim_ssmpingd_list, ss);
390
391  ssmpingd_read_on(ss);
392
393  return ss;
394}
395
396int pim_ssmpingd_start(struct in_addr source_addr)
397{
398  struct ssmpingd_sock *ss;
399
400  ss = ssmpingd_find(source_addr);
401  if (ss) {
402    /* silently ignore request to recreate entry */
403    return 0;
404  }
405
406  {
407    char source_str[100];
408    pim_inet4_dump("<src?>", source_addr, source_str, sizeof(source_str));
409    zlog_info("%s: starting ssmpingd for source %s",
410	      __PRETTY_FUNCTION__, source_str);
411  }
412
413  ss = ssmpingd_new(source_addr);
414  if (!ss) {
415    char source_str[100];
416    pim_inet4_dump("<src?>", source_addr, source_str, sizeof(source_str));
417    zlog_warn("%s: ssmpingd_new() failure for source %s",
418	      __PRETTY_FUNCTION__, source_str);
419    return -1;
420  }
421
422  return 0;
423}
424
425int pim_ssmpingd_stop(struct in_addr source_addr)
426{
427  struct ssmpingd_sock *ss;
428
429  ss = ssmpingd_find(source_addr);
430  if (!ss) {
431    char source_str[100];
432    pim_inet4_dump("<src?>", source_addr, source_str, sizeof(source_str));
433    zlog_warn("%s: could not find ssmpingd for source %s",
434	      __PRETTY_FUNCTION__, source_str);
435    return -1;
436  }
437
438  {
439    char source_str[100];
440    pim_inet4_dump("<src?>", source_addr, source_str, sizeof(source_str));
441    zlog_info("%s: stopping ssmpingd for source %s",
442	      __PRETTY_FUNCTION__, source_str);
443  }
444
445  ssmpingd_delete(ss);
446
447  return 0;
448}
449