usr.sbin/ppp/server.c

   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: src/usr.sbin/ppp/server.c,v 1.28.2.6 2002/09/01 02:12:32 brian Exp $
  27  * $DragonFly: src/usr.sbin/ppp/server.c,v 1.2 2003/06/17 04:30:01 dillon Exp $
  28  */
  29
  30 #include <sys/param.h>
  31
  32 #include <sys/socket.h>
  33 #include <netinet/in.h>
  34 #include <sys/un.h>
  35
  36 #include <errno.h>
  37 #include <stdarg.h>
  38 #include <stdio.h>
  39 #include <string.h>
  40 #include <sys/stat.h>
  41 #include <termios.h>
  42 #include <unistd.h>
  43
  44 #include "log.h"
  45 #include "descriptor.h"
  46 #include "server.h"
  47 #include "prompt.h"
  48 #include "ncpaddr.h"
  49 #include "probe.h"
  50
  51 static int
  52 server_UpdateSet(struct fdescriptor *d, fd_set *r, fd_set *w, fd_set *e, int *n)
  53 {
  54   struct server *s = descriptor2server(d);
  55   struct prompt *p;
  56   int sets;
  57
  58   sets = 0;
  59   if (r && s->fd >= 0) {
  60     if (*n < s->fd + 1)
  61       *n = s->fd + 1;
  62     FD_SET(s->fd, r);
  63     log_Printf(LogTIMER, "server: fdset(r) %d\n", s->fd);
  64     sets++;
  65   }
  66
  67   for (p = log_PromptList(); p; p = p->next)
  68     sets += descriptor_UpdateSet(&p->desc, r, w, e, n);
  69
  70   return sets;
  71 }
  72
  73 static int
  74 server_IsSet(struct fdescriptor *d, const fd_set *fdset)
  75 {
  76   struct server *s = descriptor2server(d);
  77   struct prompt *p;
  78
  79   if (s->fd >= 0 && FD_ISSET(s->fd, fdset))
  80     return 1;
  81
  82   for (p = log_PromptList(); p; p = p->next)
  83     if (descriptor_IsSet(&p->desc, fdset))
  84       return 1;
  85
  86   return 0;
  87 }
  88
  89 static void
  90 server_Read(struct fdescriptor *d, struct bundle *bundle, const fd_set *fdset)
  91 {
  92   struct server *s = descriptor2server(d);
  93   struct sockaddr_storage ss;
  94   struct sockaddr *sa = (struct sockaddr *)&ss;
  95   struct sockaddr_in *sin = (struct sockaddr_in *)&ss;
  96 #ifndef NOINET6
  97   struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&ss;
  98 #endif
  99   int ssize = sizeof ss, wfd;
 100   struct prompt *p;
 101   struct ncpaddr addr;
 102
 103   if (s->fd >= 0 && FD_ISSET(s->fd, fdset)) {
 104     wfd = accept(s->fd, sa, &ssize);
 105     if (wfd < 0)
 106       log_Printf(LogERROR, "server_Read: accept(): %s\n", strerror(errno));
 107     else if (sa->sa_len == 0) {
 108       close(wfd);
 109       wfd = -1;
 110     }
 111   } else
 112     wfd = -1;
 113
 114   if (wfd >= 0)
 115     switch (sa->sa_family) {
 116       case AF_LOCAL:
 117         log_Printf(LogPHASE, "Connected to local client.\n");
 118         break;
 119
 120       case AF_INET:
 121         ncpaddr_setsa(&addr, sa);
 122         if (ntohs(sin->sin_port) < 1024) {
 123           log_Printf(LogALERT, "Rejected client connection from %s:%u"
 124                     "(invalid port number) !\n",
 125                     ncpaddr_ntoa(&addr), ntohs(sin->sin_port));
 126           close(wfd);
 127           wfd = -1;
 128           break;
 129         }
 130         log_Printf(LogPHASE, "Connected to client from %s:%u\n",
 131                   ncpaddr_ntoa(&addr), ntohs(sin->sin_port));
 132         break;
 133
 134 #ifndef NOINET6
 135       case AF_INET6:
 136         ncpaddr_setsa(&addr, sa);
 137         if (ntohs(sin6->sin6_port) < 1024) {
 138           log_Printf(LogALERT, "Rejected client connection from %s:%u"
 139                     "(invalid port number) !\n",
 140                     ncpaddr_ntoa(&addr), ntohs(sin6->sin6_port));
 141           close(wfd);
 142           wfd = -1;
 143           break;
 144         }
 145         log_Printf(LogPHASE, "Connected to client from %s:%u\n",
 146                   ncpaddr_ntoa(&addr), ntohs(sin6->sin6_port));
 147         break;
 148 #endif
 149
 150       default:
 151         write(wfd, "Unrecognised access !\n", 22);
 152         close(wfd);
 153         wfd = -1;
 154         break;
 155     }
 156
 157   if (wfd >= 0) {
 158     if ((p = prompt_Create(s, bundle, wfd)) == NULL) {
 159       write(wfd, "Connection refused.\n", 20);
 160       close(wfd);
 161     } else {
 162       switch (sa->sa_family) {
 163         case AF_LOCAL:
 164           p->src.type = "local";
 165           strncpy(p->src.from, s->cfg.sockname, sizeof p->src.from - 1);
 166           p->src.from[sizeof p->src.from - 1] = '\0';
 167           break;
 168         case AF_INET:
 169           p->src.type = "ip";
 170           snprintf(p->src.from, sizeof p->src.from, "%s:%u",
 171                    ncpaddr_ntoa(&addr), ntohs(sin->sin_port));
 172           break;
 173 #ifndef NOINET6
 174         case AF_INET6:
 175           p->src.type = "ip6";
 176           snprintf(p->src.from, sizeof p->src.from, "%s:%u",
 177                    ncpaddr_ntoa(&addr), ntohs(sin6->sin6_port));
 178           break;
 179 #endif
 180       }
 181       prompt_TtyCommandMode(p);
 182       prompt_Required(p);
 183     }
 184   }
 185
 186   log_PromptListChanged = 0;
 187   for (p = log_PromptList(); p; p = p->next)
 188     if (descriptor_IsSet(&p->desc, fdset)) {
 189       descriptor_Read(&p->desc, bundle, fdset);
 190       if (log_PromptListChanged)
 191         break;
 192     }
 193 }
 194
 195 static int
 196 server_Write(struct fdescriptor *d __unused, struct bundle *bundle __unused, 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
 203 struct 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
 215 enum server_stat
 216 server_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
 242 enum server_stat
 243 server_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 && !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
 297 failed:
 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
 309 enum server_stat
 310 server_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   setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &s, sizeof s);
 350   if (bind(s, (struct sockaddr *)&ss, sz) < 0) {
 351     log_Printf(LogWARN, "Tcp: bind: %s\n", strerror(errno));
 352     close(s);
 353     goto failed;
 354   }
 355   if (listen(s, 5) != 0) {
 356     log_Printf(LogERROR, "Tcp: Unable to listen to socket: %s\n",
 357                strerror(errno));
 358     close(s);
 359     goto failed;
 360   }
 361   server_Close(bundle);
 362   server.fd = s;
 363   server.cfg.port = port;
 364   *server.cfg.sockname = '\0';
 365   server.cfg.mask = 0;
 366   log_Printf(LogPHASE, "Listening at port %d.\n", port);
 367   return SERVER_OK;
 368
 369 failed:
 370   if (server.fd == -1) {
 371     server.fd = -1;
 372     server.cfg.port = port;
 373     *server.cfg.sockname = '\0';
 374     server.cfg.mask = 0;
 375   }
 376   return SERVER_FAILED;
 377 }
 378
 379 int
 380 server_Close(struct bundle *bundle __unused)
 381 {
 382   if (server.fd >= 0) {
 383     if (*server.cfg.sockname != '\0') {
 384       struct sockaddr_un un;
 385       int sz = sizeof un;
 386
 387       if (getsockname(server.fd, (struct sockaddr *)&un, &sz) == 0 &&
 388           un.sun_family == AF_LOCAL && sz == sizeof un)
 389         unlink(un.sun_path);
 390     }
 391     close(server.fd);
 392     server.fd = -1;
 393     /* Drop associated prompts */
 394     log_DestroyPrompts(&server);
 395
 396     return 1;
 397   }
 398
 399   return 0;
 400 }
 401
 402 int
 403 server_Clear(struct bundle *bundle)
 404 {
 405   int ret;
 406
 407   ret = server_Close(bundle);
 408
 409   server.fd = -1;
 410   server.cfg.port = 0;
 411   *server.cfg.sockname = '\0';
 412   server.cfg.mask = 0;
 413
 414   return ret;
 415 }