1/*-
2 * Copyright (c) 1997 Brian Somers <brian@Awfulhak.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: releng/11.0/usr.sbin/ppp/server.c 277857 2015-01-28 21:33:49Z dim $
27 */
28
29#include <sys/param.h>
30
31#include <sys/socket.h>
32#include <netinet/in.h>
33#include <sys/un.h>
34
35#include <errno.h>
36#include <stdarg.h>
37#include <stdio.h>
38#include <string.h>
39#include <sys/stat.h>
40#include <termios.h>
41#include <unistd.h>
42
43#include "log.h"
44#include "descriptor.h"
45#include "server.h"
46#include "prompt.h"
47#include "ncpaddr.h"
48#include "probe.h"
49
50static int
51server_UpdateSet(struct fdescriptor *d, fd_set *r, fd_set *w, fd_set *e, int *n)
52{
53  struct server *s = descriptor2server(d);
54  struct prompt *p;
55  int sets;
56
57  sets = 0;
58  if (r && s->fd >= 0) {
59    if (*n < s->fd + 1)
60      *n = s->fd + 1;
61    FD_SET(s->fd, r);
62    log_Printf(LogTIMER, "server: fdset(r) %d\n", s->fd);
63    sets++;
64  }
65
66  for (p = log_PromptList(); p; p = p->next)
67    sets += descriptor_UpdateSet(&p->desc, r, w, e, n);
68
69  return sets;
70}
71
72static int
73server_IsSet(struct fdescriptor *d, const fd_set *fdset)
74{
75  struct server *s = descriptor2server(d);
76  struct prompt *p;
77
78  if (s->fd >= 0 && FD_ISSET(s->fd, fdset))
79    return 1;
80
81  for (p = log_PromptList(); p; p = p->next)
82    if (descriptor_IsSet(&p->desc, fdset))
83      return 1;
84
85  return 0;
86}
87
88static void
89server_Read(struct fdescriptor *d, struct bundle *bundle, const fd_set *fdset)
90{
91  struct server *s = descriptor2server(d);
92  struct sockaddr_storage ss;
93  struct sockaddr *sa = (struct sockaddr *)&ss;
94  struct sockaddr_in *sin = (struct sockaddr_in *)&ss;
95#ifndef NOINET6
96  struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&ss;
97#endif
98  int ssize = sizeof ss, wfd;
99  struct prompt *p;
100  struct ncpaddr addr;
101
102  if (s->fd >= 0 && FD_ISSET(s->fd, fdset)) {
103    wfd = accept(s->fd, sa, &ssize);
104    if (wfd < 0)
105      log_Printf(LogERROR, "server_Read: accept(): %s\n", strerror(errno));
106    else if (sa->sa_len == 0) {
107      close(wfd);
108      wfd = -1;
109    }
110  } else
111    wfd = -1;
112
113  if (wfd >= 0)
114    switch (sa->sa_family) {
115      case AF_LOCAL:
116        log_Printf(LogPHASE, "Connected to local client.\n");
117        break;
118
119      case AF_INET:
120        ncpaddr_setsa(&addr, sa);
121        if (ntohs(sin->sin_port) < 1024) {
122          log_Printf(LogALERT, "Rejected client connection from %s:%u"
123                    "(invalid port number) !\n",
124                    ncpaddr_ntoa(&addr), ntohs(sin->sin_port));
125          close(wfd);
126          wfd = -1;
127          break;
128        }
129        log_Printf(LogPHASE, "Connected to client from %s:%u\n",
130                  ncpaddr_ntoa(&addr), ntohs(sin->sin_port));
131        break;
132
133#ifndef NOINET6
134      case AF_INET6:
135        ncpaddr_setsa(&addr, sa);
136        if (ntohs(sin6->sin6_port) < 1024) {
137          log_Printf(LogALERT, "Rejected client connection from %s:%u"
138                    "(invalid port number) !\n",
139                    ncpaddr_ntoa(&addr), ntohs(sin6->sin6_port));
140          close(wfd);
141          wfd = -1;
142          break;
143        }
144        log_Printf(LogPHASE, "Connected to client from %s:%u\n",
145                  ncpaddr_ntoa(&addr), ntohs(sin6->sin6_port));
146        break;
147#endif
148
149      default:
150        write(wfd, "Unrecognised access !\n", 22);
151        close(wfd);
152        wfd = -1;
153        break;
154    }
155
156  if (wfd >= 0) {
157    if ((p = prompt_Create(s, bundle, wfd)) == NULL) {
158      write(wfd, "Connection refused.\n", 20);
159      close(wfd);
160    } else {
161      switch (sa->sa_family) {
162        case AF_LOCAL:
163          p->src.type = "local";
164          strncpy(p->src.from, s->cfg.sockname, sizeof p->src.from - 1);
165          p->src.from[sizeof p->src.from - 1] = '\0';
166          break;
167        case AF_INET:
168          p->src.type = "ip";
169          snprintf(p->src.from, sizeof p->src.from, "%s:%u",
170                   ncpaddr_ntoa(&addr), ntohs(sin->sin_port));
171          break;
172#ifndef NOINET6
173        case AF_INET6:
174          p->src.type = "ip6";
175          snprintf(p->src.from, sizeof p->src.from, "%s:%u",
176                   ncpaddr_ntoa(&addr), ntohs(sin6->sin6_port));
177          break;
178#endif
179      }
180      prompt_TtyCommandMode(p);
181      prompt_Required(p);
182    }
183  }
184
185  log_PromptListChanged = 0;
186  for (p = log_PromptList(); p; p = p->next)
187    if (descriptor_IsSet(&p->desc, fdset)) {
188      descriptor_Read(&p->desc, bundle, fdset);
189      if (log_PromptListChanged)
190        break;
191    }
192}
193
194static int
195server_Write(struct fdescriptor *d __unused, struct bundle *bundle __unused,
196	     const fd_set *fdset __unused)
197{
198  /* We never want to write here ! */
199  log_Printf(LogALERT, "server_Write: Internal error: Bad call !\n");
200  return 0;
201}
202
203struct server server = {
204  {
205    SERVER_DESCRIPTOR,
206    server_UpdateSet,
207    server_IsSet,
208    server_Read,
209    server_Write
210  },
211  -1,
212  { "", "", 0, 0 }
213};
214
215enum server_stat
216server_Reopen(struct bundle *bundle)
217{
218  char name[sizeof server.cfg.sockname];
219  struct stat st;
220  u_short port;
221  mode_t mask;
222  enum server_stat ret;
223
224  if (server.cfg.sockname[0] != '\0') {
225    strcpy(name, server.cfg.sockname);
226    mask = server.cfg.mask;
227    server_Close(bundle);
228    if (server.cfg.sockname[0] != '\0' && stat(server.cfg.sockname, &st) == 0)
229      if (!(st.st_mode & S_IFSOCK) || unlink(server.cfg.sockname) != 0)
230        return SERVER_FAILED;
231    ret = server_LocalOpen(bundle, name, mask);
232  } else if (server.cfg.port != 0) {
233    port = server.cfg.port;
234    server_Close(bundle);
235    ret = server_TcpOpen(bundle, port);
236  } else
237    ret = SERVER_UNSET;
238
239  return ret;
240}
241
242enum server_stat
243server_LocalOpen(struct bundle *bundle, const char *name, mode_t mask)
244{
245  struct sockaddr_un ifsun;
246  mode_t oldmask;
247  int s;
248
249  oldmask = (mode_t)-1;		/* Silence compiler */
250
251  if (server.cfg.sockname[0] != '\0' && !strcmp(server.cfg.sockname, name))
252    server_Close(bundle);
253
254  memset(&ifsun, '\0', sizeof ifsun);
255  ifsun.sun_len = strlen(name);
256  if (ifsun.sun_len > sizeof ifsun.sun_path - 1) {
257    log_Printf(LogERROR, "Local: %s: Path too long\n", name);
258    return SERVER_INVALID;
259  }
260  ifsun.sun_family = AF_LOCAL;
261  strcpy(ifsun.sun_path, name);
262
263  s = socket(PF_LOCAL, SOCK_STREAM, 0);
264  if (s < 0) {
265    log_Printf(LogERROR, "Local: socket: %s\n", strerror(errno));
266    goto failed;
267  }
268  setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &s, sizeof s);
269  if (mask != (mode_t)-1)
270    oldmask = umask(mask);
271  if (bind(s, (struct sockaddr *)&ifsun, sizeof ifsun) < 0) {
272    if (mask != (mode_t)-1)
273      umask(oldmask);
274    log_Printf(LogWARN, "Local: bind: %s\n", strerror(errno));
275    close(s);
276    goto failed;
277  }
278  if (mask != (mode_t)-1)
279    umask(oldmask);
280  if (listen(s, 5) != 0) {
281    log_Printf(LogERROR, "Local: Unable to listen to socket -"
282               " BUNDLE overload?\n");
283    close(s);
284    unlink(name);
285    goto failed;
286  }
287  server_Close(bundle);
288  server.fd = s;
289  server.cfg.port = 0;
290  strncpy(server.cfg.sockname, ifsun.sun_path, sizeof server.cfg.sockname - 1);
291  server.cfg.sockname[sizeof server.cfg.sockname - 1] = '\0';
292  server.cfg.mask = mask;
293  log_Printf(LogPHASE, "Listening at local socket %s.\n", name);
294
295  return SERVER_OK;
296
297failed:
298  if (server.fd == -1) {
299    server.fd = -1;
300    server.cfg.port = 0;
301    strncpy(server.cfg.sockname, ifsun.sun_path,
302            sizeof server.cfg.sockname - 1);
303    server.cfg.sockname[sizeof server.cfg.sockname - 1] = '\0';
304    server.cfg.mask = mask;
305  }
306  return SERVER_FAILED;
307}
308
309enum server_stat
310server_TcpOpen(struct bundle *bundle, u_short port)
311{
312  struct sockaddr_storage ss;
313  struct sockaddr_in *sin = (struct sockaddr_in *)&ss;
314#ifndef NOINET6
315  struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&ss;
316#endif
317  int s, sz;
318
319  if (server.cfg.port == port)
320    server_Close(bundle);
321
322  if (port == 0)
323    return SERVER_INVALID;
324
325  memset(&ss, '\0', sizeof ss);
326#ifndef NOINET6
327  if (probe.ipv6_available) {
328    sin6->sin6_family = AF_INET6;
329    sin6->sin6_port = htons(port);
330    sin6->sin6_len = (u_int8_t)sizeof ss;
331    sz = sizeof *sin6;
332    s = socket(PF_INET6, SOCK_STREAM, 0);
333  } else
334#endif
335  {
336    sin->sin_family = AF_INET;
337    sin->sin_port = htons(port);
338    sin->sin_len = (u_int8_t)sizeof ss;
339    sin->sin_addr.s_addr = INADDR_ANY;
340    sz = sizeof *sin;
341    s = socket(PF_INET, SOCK_STREAM, 0);
342  }
343
344  if (s < 0) {
345    log_Printf(LogERROR, "Tcp: socket: %s\n", strerror(errno));
346    goto failed;
347  }
348
349#ifndef NOINET6
350  if (probe.ipv6_available) {
351    int off = 0;
352    setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, (char *)&off, sizeof(off));
353  }
354#endif
355
356  setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &s, sizeof s);
357  if (bind(s, (struct sockaddr *)&ss, sz) < 0) {
358    log_Printf(LogWARN, "Tcp: bind: %s\n", strerror(errno));
359    close(s);
360    goto failed;
361  }
362  if (listen(s, 5) != 0) {
363    log_Printf(LogERROR, "Tcp: Unable to listen to socket: %s\n",
364               strerror(errno));
365    close(s);
366    goto failed;
367  }
368  server_Close(bundle);
369  server.fd = s;
370  server.cfg.port = port;
371  *server.cfg.sockname = '\0';
372  server.cfg.mask = 0;
373  log_Printf(LogPHASE, "Listening at port %d.\n", port);
374  return SERVER_OK;
375
376failed:
377  if (server.fd == -1) {
378    server.fd = -1;
379    server.cfg.port = port;
380    *server.cfg.sockname = '\0';
381    server.cfg.mask = 0;
382  }
383  return SERVER_FAILED;
384}
385
386int
387server_Close(struct bundle *bundle __unused)
388{
389  if (server.fd >= 0) {
390    if (*server.cfg.sockname != '\0') {
391      struct sockaddr_un un;
392      int sz = sizeof un;
393
394      if (getsockname(server.fd, (struct sockaddr *)&un, &sz) == 0 &&
395          un.sun_family == AF_LOCAL && sz == sizeof un)
396        unlink(un.sun_path);
397    }
398    close(server.fd);
399    server.fd = -1;
400    /* Drop associated prompts */
401    log_DestroyPrompts(&server);
402
403    return 1;
404  }
405
406  return 0;
407}
408
409int
410server_Clear(struct bundle *bundle)
411{
412  int ret;
413
414  ret = server_Close(bundle);
415
416  server.fd = -1;
417  server.cfg.port = 0;
418  *server.cfg.sockname = '\0';
419  server.cfg.mask = 0;
420
421  return ret;
422}
423