1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1997 Brian Somers <brian@Awfulhak.org>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31#include <sys/param.h>
32
33#include <sys/socket.h>
34#include <netinet/in.h>
35#include <sys/un.h>
36
37#include <errno.h>
38#include <stdarg.h>
39#include <stdio.h>
40#include <string.h>
41#include <sys/stat.h>
42#include <termios.h>
43#include <unistd.h>
44
45#include "log.h"
46#include "descriptor.h"
47#include "server.h"
48#include "prompt.h"
49#include "ncpaddr.h"
50#include "probe.h"
51
52static int
53server_UpdateSet(struct fdescriptor *d, fd_set *r, fd_set *w, fd_set *e, int *n)
54{
55  struct server *s = descriptor2server(d);
56  struct prompt *p;
57  int sets;
58
59  sets = 0;
60  if (r && s->fd >= 0) {
61    if (*n < s->fd + 1)
62      *n = s->fd + 1;
63    FD_SET(s->fd, r);
64    log_Printf(LogTIMER, "server: fdset(r) %d\n", s->fd);
65    sets++;
66  }
67
68  for (p = log_PromptList(); p; p = p->next)
69    sets += descriptor_UpdateSet(&p->desc, r, w, e, n);
70
71  return sets;
72}
73
74static int
75server_IsSet(struct fdescriptor *d, const fd_set *fdset)
76{
77  struct server *s = descriptor2server(d);
78  struct prompt *p;
79
80  if (s->fd >= 0 && FD_ISSET(s->fd, fdset))
81    return 1;
82
83  for (p = log_PromptList(); p; p = p->next)
84    if (descriptor_IsSet(&p->desc, fdset))
85      return 1;
86
87  return 0;
88}
89
90static void
91server_Read(struct fdescriptor *d, struct bundle *bundle, const fd_set *fdset)
92{
93  struct server *s = descriptor2server(d);
94  struct sockaddr_storage ss;
95  struct sockaddr *sa = (struct sockaddr *)&ss;
96  struct sockaddr_in *sin = (struct sockaddr_in *)&ss;
97#ifndef NOINET6
98  struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&ss;
99#endif
100  int ssize = sizeof ss, wfd;
101  struct prompt *p;
102  struct ncpaddr addr;
103
104  if (s->fd >= 0 && FD_ISSET(s->fd, fdset)) {
105    wfd = accept(s->fd, sa, &ssize);
106    if (wfd < 0)
107      log_Printf(LogERROR, "server_Read: accept(): %s\n", strerror(errno));
108    else if (sa->sa_len == 0) {
109      close(wfd);
110      wfd = -1;
111    }
112  } else
113    wfd = -1;
114
115  if (wfd >= 0)
116    switch (sa->sa_family) {
117      case AF_LOCAL:
118        log_Printf(LogPHASE, "Connected to local client.\n");
119        break;
120
121      case AF_INET:
122        ncpaddr_setsa(&addr, sa);
123        if (ntohs(sin->sin_port) < 1024) {
124          log_Printf(LogALERT, "Rejected client connection from %s:%u"
125                    "(invalid port number) !\n",
126                    ncpaddr_ntoa(&addr), ntohs(sin->sin_port));
127          close(wfd);
128          wfd = -1;
129          break;
130        }
131        log_Printf(LogPHASE, "Connected to client from %s:%u\n",
132                  ncpaddr_ntoa(&addr), ntohs(sin->sin_port));
133        break;
134
135#ifndef NOINET6
136      case AF_INET6:
137        ncpaddr_setsa(&addr, sa);
138        if (ntohs(sin6->sin6_port) < 1024) {
139          log_Printf(LogALERT, "Rejected client connection from %s:%u"
140                    "(invalid port number) !\n",
141                    ncpaddr_ntoa(&addr), ntohs(sin6->sin6_port));
142          close(wfd);
143          wfd = -1;
144          break;
145        }
146        log_Printf(LogPHASE, "Connected to client from %s:%u\n",
147                  ncpaddr_ntoa(&addr), ntohs(sin6->sin6_port));
148        break;
149#endif
150
151      default:
152        write(wfd, "Unrecognised access !\n", 22);
153        close(wfd);
154        wfd = -1;
155        break;
156    }
157
158  if (wfd >= 0) {
159    if ((p = prompt_Create(s, bundle, wfd)) == NULL) {
160      write(wfd, "Connection refused.\n", 20);
161      close(wfd);
162    } else {
163      switch (sa->sa_family) {
164        case AF_LOCAL:
165          p->src.type = "local";
166          strncpy(p->src.from, s->cfg.sockname, sizeof p->src.from - 1);
167          p->src.from[sizeof p->src.from - 1] = '\0';
168          break;
169        case AF_INET:
170          p->src.type = "ip";
171          snprintf(p->src.from, sizeof p->src.from, "%s:%u",
172                   ncpaddr_ntoa(&addr), ntohs(sin->sin_port));
173          break;
174#ifndef NOINET6
175        case AF_INET6:
176          p->src.type = "ip6";
177          snprintf(p->src.from, sizeof p->src.from, "%s:%u",
178                   ncpaddr_ntoa(&addr), ntohs(sin6->sin6_port));
179          break;
180#endif
181      }
182      prompt_TtyCommandMode(p);
183      prompt_Required(p);
184    }
185  }
186
187  log_PromptListChanged = 0;
188  for (p = log_PromptList(); p; p = p->next)
189    if (descriptor_IsSet(&p->desc, fdset)) {
190      descriptor_Read(&p->desc, bundle, fdset);
191      if (log_PromptListChanged)
192        break;
193    }
194}
195
196static int
197server_Write(struct fdescriptor *d __unused, struct bundle *bundle __unused,
198	     const fd_set *fdset __unused)
199{
200  /* We never want to write here ! */
201  log_Printf(LogALERT, "server_Write: Internal error: Bad call !\n");
202  return 0;
203}
204
205struct server server = {
206  {
207    SERVER_DESCRIPTOR,
208    server_UpdateSet,
209    server_IsSet,
210    server_Read,
211    server_Write
212  },
213  -1,
214  { "", "", 0, 0 }
215};
216
217enum server_stat
218server_Reopen(struct bundle *bundle)
219{
220  char name[sizeof server.cfg.sockname];
221  struct stat st;
222  u_short port;
223  mode_t mask;
224  enum server_stat ret;
225
226  if (server.cfg.sockname[0] != '\0') {
227    strcpy(name, server.cfg.sockname);
228    mask = server.cfg.mask;
229    server_Close(bundle);
230    if (server.cfg.sockname[0] != '\0' && stat(server.cfg.sockname, &st) == 0)
231      if (!(st.st_mode & S_IFSOCK) || unlink(server.cfg.sockname) != 0)
232        return SERVER_FAILED;
233    ret = server_LocalOpen(bundle, name, mask);
234  } else if (server.cfg.port != 0) {
235    port = server.cfg.port;
236    server_Close(bundle);
237    ret = server_TcpOpen(bundle, port);
238  } else
239    ret = SERVER_UNSET;
240
241  return ret;
242}
243
244enum server_stat
245server_LocalOpen(struct bundle *bundle, const char *name, mode_t mask)
246{
247  struct sockaddr_un ifsun;
248  mode_t oldmask;
249  int s;
250
251  oldmask = (mode_t)-1;		/* Silence compiler */
252
253  if (server.cfg.sockname[0] != '\0' && !strcmp(server.cfg.sockname, name))
254    server_Close(bundle);
255
256  memset(&ifsun, '\0', sizeof ifsun);
257  ifsun.sun_len = strlen(name);
258  if (ifsun.sun_len > sizeof ifsun.sun_path - 1) {
259    log_Printf(LogERROR, "Local: %s: Path too long\n", name);
260    return SERVER_INVALID;
261  }
262  ifsun.sun_family = AF_LOCAL;
263  strcpy(ifsun.sun_path, name);
264
265  s = socket(PF_LOCAL, SOCK_STREAM, 0);
266  if (s < 0) {
267    log_Printf(LogERROR, "Local: socket: %s\n", strerror(errno));
268    goto failed;
269  }
270  setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &s, sizeof s);
271  if (mask != (mode_t)-1)
272    oldmask = umask(mask);
273  if (bind(s, (struct sockaddr *)&ifsun, sizeof ifsun) < 0) {
274    if (mask != (mode_t)-1)
275      umask(oldmask);
276    log_Printf(LogWARN, "Local: bind: %s\n", strerror(errno));
277    close(s);
278    goto failed;
279  }
280  if (mask != (mode_t)-1)
281    umask(oldmask);
282  if (listen(s, 5) != 0) {
283    log_Printf(LogERROR, "Local: Unable to listen to socket -"
284               " BUNDLE overload?\n");
285    close(s);
286    unlink(name);
287    goto failed;
288  }
289  server_Close(bundle);
290  server.fd = s;
291  server.cfg.port = 0;
292  strncpy(server.cfg.sockname, ifsun.sun_path, sizeof server.cfg.sockname - 1);
293  server.cfg.sockname[sizeof server.cfg.sockname - 1] = '\0';
294  server.cfg.mask = mask;
295  log_Printf(LogPHASE, "Listening at local socket %s.\n", name);
296
297  return SERVER_OK;
298
299failed:
300  if (server.fd == -1) {
301    server.fd = -1;
302    server.cfg.port = 0;
303    strncpy(server.cfg.sockname, ifsun.sun_path,
304            sizeof server.cfg.sockname - 1);
305    server.cfg.sockname[sizeof server.cfg.sockname - 1] = '\0';
306    server.cfg.mask = mask;
307  }
308  return SERVER_FAILED;
309}
310
311enum server_stat
312server_TcpOpen(struct bundle *bundle, u_short port)
313{
314  struct sockaddr_storage ss;
315  struct sockaddr_in *sin = (struct sockaddr_in *)&ss;
316#ifndef NOINET6
317  struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&ss;
318#endif
319  int s, sz;
320
321  if (server.cfg.port == port)
322    server_Close(bundle);
323
324  if (port == 0)
325    return SERVER_INVALID;
326
327  memset(&ss, '\0', sizeof ss);
328#ifndef NOINET6
329  if (probe.ipv6_available) {
330    sin6->sin6_family = AF_INET6;
331    sin6->sin6_port = htons(port);
332    sin6->sin6_len = (u_int8_t)sizeof ss;
333    sz = sizeof *sin6;
334    s = socket(PF_INET6, SOCK_STREAM, 0);
335  } else
336#endif
337  {
338    sin->sin_family = AF_INET;
339    sin->sin_port = htons(port);
340    sin->sin_len = (u_int8_t)sizeof ss;
341    sin->sin_addr.s_addr = INADDR_ANY;
342    sz = sizeof *sin;
343    s = socket(PF_INET, SOCK_STREAM, 0);
344  }
345
346  if (s < 0) {
347    log_Printf(LogERROR, "Tcp: socket: %s\n", strerror(errno));
348    goto failed;
349  }
350
351#ifndef NOINET6
352  if (probe.ipv6_available) {
353    int off = 0;
354    setsockopt(s, IPPROTO_IPV6, IPV6_V6ONLY, (char *)&off, sizeof(off));
355  }
356#endif
357
358  setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &s, sizeof s);
359  if (bind(s, (struct sockaddr *)&ss, sz) < 0) {
360    log_Printf(LogWARN, "Tcp: bind: %s\n", strerror(errno));
361    close(s);
362    goto failed;
363  }
364  if (listen(s, 5) != 0) {
365    log_Printf(LogERROR, "Tcp: Unable to listen to socket: %s\n",
366               strerror(errno));
367    close(s);
368    goto failed;
369  }
370  server_Close(bundle);
371  server.fd = s;
372  server.cfg.port = port;
373  *server.cfg.sockname = '\0';
374  server.cfg.mask = 0;
375  log_Printf(LogPHASE, "Listening at port %d.\n", port);
376  return SERVER_OK;
377
378failed:
379  if (server.fd == -1) {
380    server.fd = -1;
381    server.cfg.port = port;
382    *server.cfg.sockname = '\0';
383    server.cfg.mask = 0;
384  }
385  return SERVER_FAILED;
386}
387
388int
389server_Close(struct bundle *bundle __unused)
390{
391  if (server.fd >= 0) {
392    if (*server.cfg.sockname != '\0') {
393      struct sockaddr_un un;
394      int sz = sizeof un;
395
396      if (getsockname(server.fd, (struct sockaddr *)&un, &sz) == 0 &&
397          un.sun_family == AF_LOCAL && sz == sizeof un)
398        unlink(un.sun_path);
399    }
400    close(server.fd);
401    server.fd = -1;
402    /* Drop associated prompts */
403    log_DestroyPrompts(&server);
404
405    return 1;
406  }
407
408  return 0;
409}
410
411int
412server_Clear(struct bundle *bundle)
413{
414  int ret;
415
416  ret = server_Close(bundle);
417
418  server.fd = -1;
419  server.cfg.port = 0;
420  *server.cfg.sockname = '\0';
421  server.cfg.mask = 0;
422
423  return ret;
424}
425