release/src/router/pptpd/pptpctrl.c

   1 /*
   2  * pptpctrl.c
   3  *
   4  * PPTP control connection between PAC-PNS pair
   5  *
   6  * $Id: pptpctrl.c,v 1.20 2006/12/08 00:01:40 quozl Exp $
   7  */
   8
   9 #ifdef HAVE_CONFIG_H
  10 #include "config.h"
  11 #endif
  12
  13 #ifdef __linux__
  14 #define _GNU_SOURCE 1           /* kill() prototype, broken arpa/inet.h */
  15 #endif
  16
  17 #include "our_syslog.h"
  18
  19 #include <fcntl.h>
  20 #include <errno.h>
  21 #include <signal.h>
  22 #include <unistd.h>
  23 #include <string.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <time.h>
  27 #include <sys/time.h>
  28 #include <dirent.h>
  29 #include <sys/types.h>
  30 #include <sys/wait.h>
  31 #include <sys/socket.h>
  32 #include <netinet/in.h>
  33 #include <arpa/inet.h>
  34 #ifdef HAVE_OPENPTY
  35 #ifdef HAVE_PTY_H
  36 #include <pty.h>
  37 #include <termios.h>
  38 #endif
  39 #ifdef HAVE_LIBUTIL_H
  40 #include <libutil.h>
  41 #endif
  42 #endif
  43
  44 #ifdef __UCLIBC__
  45 #define socklen_t int
  46 #endif
  47
  48 #include "compat.h"
  49 #include "pptpctrl.h"
  50 #include "pptpgre.h"
  51 #include "pptpdefs.h"
  52 #include "ctrlpacket.h"
  53 #include "defaults.h"
  54 // placing net/if.h here fixes build on Solaris
  55 #include <net/if.h>
  56
  57 static char *ppp_binary = PPP_BINARY;
  58 static int pptp_logwtmp;
  59 static int noipparam;                   /* if true, don't send ipparam to ppp */
  60 static char speed[32];
  61 static char pppdxfig[256];
  62 static pid_t pppfork;                   /* so we can kill it after disconnect */
  63
  64 /*
  65  * Global to handle dying
  66  *
  67  * I'd be nice if someone could figure out a way to do it
  68  * without the global, but i don't think you can.. -tmk
  69  */
  70 #define clientSocket 0          /* in case it changes back to a variable */
  71 static u_int32_t call_id_pair;  /* call id (to terminate call) */
  72
  73 /* Needed by this and ctrlpacket.c */
  74 int pptpctrl_debug = 0;         /* specifies if debugging is on or off */
  75 uint16_t unique_call_id = 0xFFFF;       /* Start value for our call IDs on this TCP link */
  76
  77 int gargc;                     /* Command line argument count */
  78 char **gargv;                  /* Command line argument vector */
  79
  80 /* Local function prototypes */
  81 static void bail(int sigraised);
  82 static void pptp_handle_ctrl_connection(char **pppaddrs, struct in_addr *inetaddrs);
  83
  84 static int startCall(char **pppaddrs, struct in_addr *inetaddrs);
  85 static void launch_pppd(char **pppaddrs, struct in_addr *inetaddrs);
  86
  87 /* Oh the horror.. lets hope this covers all the ones we have to handle */
  88 #if defined(O_NONBLOCK) && !defined(__sun__) && !defined(__sun)
  89 #define OUR_NB_MODE O_NONBLOCK
  90 #else
  91 #define OUR_NB_MODE O_NDELAY
  92 #endif
  93
  94 /* read a command line argument, a flag alone */
  95 #define GETARG_INT(X) \
  96         X = atoi(argv[arg++])
  97
  98 /* read a command line argument, a string alone */
  99 #define GETARG_STRING(X) \
 100         X = strdup(argv[arg++])
 101
 102 /* read a command line argument, a presence flag followed by string */
 103 #define GETARG_VALUE(X) \
 104         if(atoi(argv[arg++]) != 0) \
 105                 strlcpy(X, argv[arg++], sizeof(X)); \
 106         else \
 107                 *X = '\0'
 108
 109 int main(int argc, char **argv)
 110 {
 111         char pppLocal[16];              /* local IP to pass to pppd */
 112         char pppRemote[16];             /* remote IP address to pass to pppd */
 113         struct sockaddr_in addr;        /* client address */
 114         socklen_t addrlen;
 115         int arg = 1;
 116         int flags;
 117         struct in_addr inetaddrs[2];
 118         char *pppaddrs[2] = { pppLocal, pppRemote };
 119
 120         gargc = argc;
 121         gargv = argv;
 122
 123         /* fail if argument count invalid */
 124         if (argc < 7) {
 125                 fprintf(stderr, "pptpctrl: insufficient arguments, see man pptpctrl\n");
 126                 exit(2);
 127         }
 128
 129         /* open a connection to the syslog daemon */
 130         openlog("pptpd", LOG_PID, PPTP_FACILITY);
 131
 132         /* autoreap if supported */
 133         signal(SIGCHLD, SIG_IGN);
 134
 135         /* note: update pptpctrl.8 if the argument list format is changed */
 136         GETARG_INT(pptpctrl_debug);
 137         GETARG_INT(noipparam);
 138         GETARG_VALUE(pppdxfig);
 139         GETARG_VALUE(speed);
 140         GETARG_VALUE(pppLocal);
 141         GETARG_VALUE(pppRemote);
 142         if (arg < argc) GETARG_INT(unique_call_id);
 143         if (arg < argc) GETARG_STRING(ppp_binary);
 144         if (arg < argc) GETARG_INT(pptp_logwtmp);
 145
 146         if (pptpctrl_debug) {
 147                 if (*pppLocal)
 148                         syslog(LOG_DEBUG, "CTRL: local address = %s", pppLocal);
 149                 if (*pppRemote)
 150                         syslog(LOG_DEBUG, "CTRL: remote address = %s", pppRemote);
 151                 if (*speed)
 152                         syslog(LOG_DEBUG, "CTRL: pppd speed = %s", speed);
 153                 if (*pppdxfig)
 154                         syslog(LOG_DEBUG, "CTRL: pppd options file = %s", pppdxfig);
 155         }
 156
 157         addrlen = sizeof(addr);
 158         if (getsockname(clientSocket, (struct sockaddr *) &addr, &addrlen) != 0) {
 159                 syslog(LOG_ERR, "CTRL: getsockname() failed");
 160                 syslog_perror("getsockname");
 161                 close(clientSocket);
 162                 bail(0);        /* NORETURN */
 163         }
 164         inetaddrs[0] = addr.sin_addr;
 165
 166         addrlen = sizeof(addr);
 167         if (getpeername(clientSocket, (struct sockaddr *) &addr, &addrlen) != 0) {
 168                 syslog(LOG_ERR, "CTRL: getpeername() failed");
 169                 syslog_perror("getpeername");
 170                 close(clientSocket);
 171                 bail(0);        /* NORETURN */
 172         }
 173         inetaddrs[1] = addr.sin_addr;
 174
 175         /* Set non-blocking */
 176         if ((flags = fcntl(clientSocket, F_GETFL, arg /* ignored */)) == -1 ||
 177             fcntl(clientSocket, F_SETFL, flags|OUR_NB_MODE) == -1) {
 178                 syslog(LOG_ERR, "CTRL: Failed to set client socket non-blocking");
 179                 syslog_perror("fcntl");
 180                 close(clientSocket);
 181                 bail(0);        /* NORETURN */
 182         }
 183
 184
 185         /* Fiddle with argv */
 186         my_setproctitle(gargc, gargv, "pptpd [%s]%20c",
 187             inet_ntoa(addr.sin_addr), ' ');
 188
 189         /* be ready for a grisly death */
 190         sigpipe_create();
 191         sigpipe_assign(SIGTERM);
 192         NOTE_VALUE(PAC, call_id_pair, htons(-1));
 193         NOTE_VALUE(PNS, call_id_pair, htons(-1));
 194
 195         syslog(LOG_INFO, "CTRL: Client %s control connection started", inet_ntoa(addr.sin_addr));
 196         pptp_handle_ctrl_connection(pppaddrs, inetaddrs);
 197         syslog(LOG_DEBUG, "CTRL: Reaping child PPP[%i]", pppfork);
 198         if (pppfork > 0)
 199                 waitpid(pppfork, NULL, 0);
 200         syslog(LOG_INFO, "CTRL: Client %s control connection finished", inet_ntoa(addr.sin_addr));
 201
 202         bail(0);                /* NORETURN */
 203         return 1;               /* make gcc happy */
 204 }
 205
 206
 207 /*
 208  * Local functions only below
 209  */
 210
 211 /*
 212  * pptp_handle_ctrl_connection
 213  *
 214  * 1. read a packet (should be start_ctrl_conn_rqst)
 215  * 2. reply to packet (send a start_ctrl_conn_rply)
 216  * 3. proceed with GRE and CTRL connections
 217  *
 218  * args: pppaddrs - ppp local and remote addresses (strings)
 219  *       inetaddrs - local and client socket address
 220  * retn: 0 success, -1 failure
 221  */
 222 static void pptp_handle_ctrl_connection(char **pppaddrs, struct in_addr *inetaddrs)
 223 {
 224
 225         /* For echo requests used to check link is alive */
 226         int echo_wait = FALSE;          /* Waiting for echo? */
 227         u_int32_t echo_count = 0;       /* Sequence # of echo */
 228         time_t echo_time = 0;           /* Time last echo req sent */
 229         struct timeval idleTime;        /* How long to select() */
 230
 231         /* General local variables */
 232         ssize_t rply_size;              /* Reply packet size */
 233         fd_set fds;                     /* For select() */
 234         int maxfd = clientSocket;       /* For select() */
 235         int send_packet;                /* Send a packet this time? */
 236 #if BSDUSER_PPP || SLIRP
 237 /* not needed by stuff which uses socketpair() in startCall() */
 238 #define init 1
 239 #else
 240         int init = 0;                   /* Has pppd initialized the pty? */
 241 #endif
 242         int pty_fd = -1;                /* File descriptor of pty */
 243         int gre_fd = -1;                /* Network file descriptor */
 244         int sig_fd = sigpipe_fd();      /* Signal pipe descriptor       */
 245
 246         unsigned char packet[PPTP_MAX_CTRL_PCKT_SIZE];
 247         unsigned char rply_packet[PPTP_MAX_CTRL_PCKT_SIZE];
 248
 249         for (;;) {
 250
 251                 FD_ZERO(&fds);
 252                 FD_SET(sig_fd, &fds);
 253                 FD_SET(clientSocket, &fds);
 254                 if (pty_fd != -1)
 255                         FD_SET(pty_fd, &fds);
 256                 if (gre_fd != -1 && init)
 257                         FD_SET(gre_fd, &fds);
 258
 259                 /* set timeout */
 260                 if (encaps_gre(-1, NULL, 0) || decaps_hdlc(-1, NULL, 0)) {
 261                         idleTime.tv_sec = 0;
 262                         idleTime.tv_usec = 50000; /* don't ack immediately */
 263                 } else {
 264                         idleTime.tv_sec = IDLE_WAIT;
 265                         idleTime.tv_usec = 0;
 266                 }
 267
 268                 /* default: do nothing */
 269                 send_packet = FALSE;
 270
 271                 switch (select(maxfd + 1, &fds, NULL, NULL, &idleTime)) {
 272                 case -1:        /* Error with select() */
 273                         if (errno != EINTR)
 274                                 syslog(LOG_ERR, "CTRL: Error with select(), quitting");
 275                         goto leave_clear_call;
 276
 277                 case 0:
 278                         if (decaps_hdlc(-1, NULL, 0)) {
 279                                 if(decaps_hdlc(-1, encaps_gre, gre_fd))
 280                                         syslog(LOG_ERR, "CTRL: GRE re-xmit failed");
 281                         } else if (encaps_gre(-1, NULL, 0))
 282                                 /* Pending ack and nothing else to do */
 283                                 encaps_gre(gre_fd, NULL, 0);    /* send ack with no payload */
 284                         else if (echo_wait != TRUE) {
 285                                 /* Timeout. Start idle link detection. */
 286                                 echo_count++;
 287                                 if (pptpctrl_debug)
 288                                         syslog(LOG_DEBUG, "CTRL: Sending ECHO REQ id %d", echo_count);
 289                                 time(&echo_time);
 290                                 make_echo_req_packet(rply_packet, &rply_size, echo_count);
 291                                 echo_wait = TRUE;
 292                                 send_packet = TRUE;
 293                         }
 294                         break;
 295
 296                 default:
 297                         break;
 298                 }
 299
 300                 /* check for pending SIGTERM delivery */
 301                 if (FD_ISSET(sig_fd, &fds)) {
 302                         if (sigpipe_read() == SIGTERM)
 303                                 bail(SIGTERM);
 304                 }
 305
 306                 /* detect startup of pppd */
 307 #ifndef init
 308                 if (!init && pty_fd != -1 && FD_ISSET(pty_fd, &fds))
 309                         init = 1;
 310 #endif
 311
 312                 /* handle actual packets */
 313
 314                 /* send from pty off via GRE */
 315                 if (pty_fd != -1 && FD_ISSET(pty_fd, &fds) && decaps_hdlc(pty_fd, encaps_gre, gre_fd) < 0) {
 316                         syslog(LOG_ERR, "CTRL: PTY read or GRE write failed (pty,gre)=(%d,%d)", pty_fd, gre_fd);
 317                         break;
 318                 }
 319                 /* send from GRE off to pty */
 320                 if (gre_fd != -1 && FD_ISSET(gre_fd, &fds) && decaps_gre(gre_fd, encaps_hdlc, pty_fd) < 0) {
 321                         if (gre_fd == 6 && pty_fd == 5) {
 322                                 syslog(LOG_ERR, "CTRL: GRE-tunnel has collapsed (GRE read or PTY write failed (gre,pty)=(%d,%d))", gre_fd, pty_fd);
 323                         } else {
 324                                 syslog(LOG_ERR, "CTRL: GRE read or PTY write failed (gre,pty)=(%d,%d)", gre_fd, pty_fd);
 325                         }
 326                         break;
 327                 }
 328                 /* handle control messages */
 329
 330                 if (FD_ISSET(clientSocket, &fds)) {
 331                         send_packet = TRUE;
 332                         switch (read_pptp_packet(clientSocket, packet, rply_packet, &rply_size)) {
 333                         case 0:
 334                                 syslog(LOG_ERR, "CTRL: CTRL read failed");
 335                                 goto leave_drop_call;
 336
 337                         case -1:
 338                                 send_packet = FALSE;
 339                                 break;
 340
 341                         case STOP_CTRL_CONN_RQST:
 342                                 if (pptpctrl_debug)
 343                                         syslog(LOG_DEBUG, "CTRL: Received STOP CTRL CONN request (disconnecting)");
 344                                 if (gre_fd != -1 || pty_fd != -1)
 345                                         syslog(LOG_WARNING, "CTRL: Request to close control connection when call is open, closing");
 346                                 send_pptp_packet(clientSocket, rply_packet, rply_size);
 347                                 goto leave_drop_call;
 348
 349                         case CALL_CLR_RQST:
 350                                 if(pptpctrl_debug)
 351                                         syslog(LOG_DEBUG, "CTRL: Received CALL CLR request (closing call)");
 352                                 if (gre_fd == -1 || pty_fd == -1)
 353                                         syslog(LOG_WARNING, "CTRL: Request to close call but call not open");
 354                                 if (gre_fd != -1) {
 355                                         FD_CLR(gre_fd, &fds);
 356                                         close(gre_fd);
 357                                         gre_fd = -1;
 358                                 }
 359                                 if (pty_fd != -1) {
 360                                         FD_CLR(pty_fd, &fds);
 361                                         close(pty_fd);
 362                                         pty_fd = -1;
 363                                 }
 364                                 /* violating RFC */
 365                                 goto leave_drop_call;
 366
 367                         case OUT_CALL_RQST:
 368                                 /* for killing off the link later (ugly) */
 369                                 NOTE_VALUE(PAC, call_id_pair, ((struct pptp_out_call_rply *) (rply_packet))->call_id);
 370                                 NOTE_VALUE(PNS, call_id_pair, ((struct pptp_out_call_rply *) (rply_packet))->call_id_peer);
 371                                 if (gre_fd != -1 || pty_fd != -1) {
 372                                         syslog(LOG_WARNING, "CTRL: Request to open call when call is already open, closing");
 373                                         if (gre_fd != -1) {
 374                                                 FD_CLR(gre_fd, &fds);
 375                                                 close(gre_fd);
 376                                                 gre_fd = -1;
 377                                         }
 378                                         if (pty_fd != -1) {
 379                                                 FD_CLR(pty_fd, &fds);
 380                                                 close(pty_fd);
 381                                                 pty_fd = -1;
 382                                         }
 383                                 }
 384                                 /* change process title for accounting and status scripts */
 385                                 my_setproctitle(gargc, gargv,
 386                                       "pptpd [%s:%04X - %04X]",
 387                                       inet_ntoa(inetaddrs[1]),
 388                                       ntohs(((struct pptp_out_call_rply *) (rply_packet))->call_id_peer),
 389                                       ntohs(((struct pptp_out_call_rply *) (rply_packet))->call_id));
 390                                 /* start the call, by launching pppd */
 391                                 syslog(LOG_INFO, "CTRL: Starting call (launching pppd, opening GRE)");
 392                                 pty_fd = startCall(pppaddrs, inetaddrs);
 393                                 if (pty_fd > maxfd) maxfd = pty_fd;
 394                                 if ((gre_fd = pptp_gre_init(call_id_pair, pty_fd, inetaddrs)) > maxfd)
 395                                         maxfd = gre_fd;
 396                                 break;
 397
 398                         case ECHO_RPLY:
 399                                 if (echo_wait == TRUE && ((struct pptp_echo_rply *) (packet))->identifier == echo_count)
 400                                         echo_wait = FALSE;
 401                                 else
 402                                         syslog(LOG_WARNING, "CTRL: Unexpected ECHO REPLY packet");
 403                                 /* FALLTHRU */
 404                         case SET_LINK_INFO:
 405                                 send_packet = FALSE;
 406                                 break;
 407
 408 #ifdef PNS_MODE
 409                         case IN_CALL_RQST:
 410                         case IN_CALL_RPLY:
 411                         case IN_CALL_CONN:
 412 #endif
 413
 414                         case CALL_DISCONN_NTFY:
 415                         case STOP_CTRL_CONN_RPLY:
 416                                 /* These don't generate replies.  Also they come from things we don't send in this section. */
 417                                 syslog(LOG_WARNING, "CTRL: Got a reply to a packet we didn't send");
 418                                 send_packet = FALSE;
 419                                 break;
 420
 421                         /* Otherwise, the already-formed reply will do fine, so send it */
 422                         }
 423                 }
 424
 425                 /* send reply packet - this may block, but it should be very rare */
 426                 if (send_packet == TRUE && send_pptp_packet(clientSocket, rply_packet, rply_size) < 0) {
 427                         syslog(LOG_ERR, "CTRL: Error sending GRE, aborting call");
 428                         goto leave_clear_call;
 429                 }
 430
 431                 /* waiting for echo reply and curtime - echo_time > max wait */
 432                 if (echo_wait == TRUE && (time(NULL) - echo_time) > MAX_ECHO_WAIT) {
 433                         syslog(LOG_INFO, "CTRL: Session timed out, ending call");
 434                         goto leave_clear_call;
 435                 }
 436         }
 437         /* Finished! :-) */
 438 leave_drop_call:
 439         NOTE_VALUE(PAC, call_id_pair, htons(-1));
 440         NOTE_VALUE(PNS, call_id_pair, htons(-1));
 441         close(clientSocket);
 442 leave_clear_call:
 443         /* leave clientSocket and call_id_pair alone for bail() */
 444         if (gre_fd != -1)
 445                 close(gre_fd);
 446         gre_fd = -1;
 447         if (pty_fd != -1)
 448                 close(pty_fd);
 449         pty_fd = -1;
 450         return;
 451 #ifdef init
 452 #undef init
 453 #endif
 454 }
 455
 456
 457 /*
 458  * This is the custom exit() for this program.
 459  *
 460  * Updated to also be the default SIGTERM handler, and if
 461  * the link is going down for unnatural reasons, we will close it
 462  * right now, it's only been tested for win98, other tests would be nice
 463  * -tmk
 464  */
 465 static void bail(int sigraised)
 466 {
 467         if (sigraised)
 468                 syslog(LOG_INFO, "CTRL: Exiting on signal %d", sigraised);
 469
 470         /* send a disconnect to the other end */
 471         /* ignore any errors */
 472         if (GET_VALUE(PAC, call_id_pair) != htons(-1)) {
 473                 fd_set connSet;         /* fd_set for select() */
 474                 struct timeval tv;      /* time to wait for reply */
 475                 unsigned char packet[PPTP_MAX_CTRL_PCKT_SIZE];
 476                 unsigned char rply_packet[PPTP_MAX_CTRL_PCKT_SIZE];
 477                 ssize_t rply_size;      /* reply packet size */
 478                 int pkt;
 479                 int retry = 0;
 480
 481                 if (pptpctrl_debug)
 482                         syslog(LOG_DEBUG, "CTRL: Exiting with active call");
 483
 484                 make_call_admin_shutdown(rply_packet, &rply_size);
 485                 if(send_pptp_packet(clientSocket, rply_packet, rply_size) < 0)
 486                         goto skip;
 487
 488                 make_stop_ctrl_req(rply_packet, &rply_size);
 489                 if(send_pptp_packet(clientSocket, rply_packet, rply_size) < 0)
 490                         goto skip;
 491
 492                 FD_ZERO(&connSet);
 493                 FD_SET(clientSocket, &connSet);
 494                 tv.tv_sec = 5;  /* wait 5 secs for a reply then quit */
 495                 tv.tv_usec = 0;
 496
 497                 /* Wait for STOP CTRL CONN RQST or RPLY */
 498                 while (select(clientSocket + 1, &connSet, NULL, NULL, &tv) == 1) {
 499                         switch((pkt = read_pptp_packet(clientSocket, packet, rply_packet, &rply_size))) {
 500                         case STOP_CTRL_CONN_RQST:
 501                                 send_pptp_packet(clientSocket, rply_packet, rply_size);
 502                                 goto skip;
 503                         case CALL_CLR_RQST:
 504                                 syslog(LOG_WARNING, "CTRL: Got call clear request after call manually shutdown - buggy client");
 505                                 break;
 506                         case STOP_CTRL_CONN_RPLY:
 507                                 goto skip;
 508                         case -1:
 509                                 syslog(LOG_WARNING, "CTRL: Retryable error in disconnect sequence");
 510                                 retry++;
 511                                 break;
 512                         case 0:
 513                                 syslog(LOG_WARNING, "CTRL: Fatal error reading control message in disconnect sequence");
 514                                 goto skip;
 515                         default:
 516                                 syslog(LOG_WARNING, "CTRL: Unexpected control message %d in disconnect sequence", pkt);
 517                                 retry++;
 518                                 break;
 519                         }
 520                         tv.tv_sec = 5;  /* wait 5 secs for another reply then quit */
 521                         tv.tv_usec = 0;
 522                         if (retry > 100) {
 523                                 syslog(LOG_WARNING, "CTRL: Too many retries (%d) - giving up", retry);
 524                                 break;
 525                         }
 526                 }
 527
 528         skip:
 529                 close(clientSocket);
 530         }
 531
 532         if (pptpctrl_debug)
 533                 syslog(LOG_DEBUG, "CTRL: Exiting now");
 534 }
 535
 536 /*
 537  * startCall
 538  *
 539  * Launches PPPD for the call.
 540  *
 541  * args:        pppaddrs - local/remote IPs or "" for either/both if none
 542  * retn:        pty file descriptor
 543  *
 544  */
 545 static int startCall(char **pppaddrs, struct in_addr *inetaddrs)
 546 {
 547         /* PTY/TTY pair for talking to PPPd */
 548         int pty_fd, tty_fd;
 549         /* register pids of children */
 550 #if BSDUSER_PPP || SLIRP
 551         int sockfd[2];
 552
 553 #ifndef AF_LOCAL
 554 #ifdef AF_UNIX
 555 #define AF_LOCAL AF_UNIX /* Old BSD */
 556 #else
 557 #define AF_LOCAL AF_FILE /* POSIX */
 558 #endif
 559 #endif
 560
 561         /* userspace ppp doesn't need to waste a real pty/tty pair */
 562         if (socketpair(AF_LOCAL, SOCK_STREAM, 0, sockfd)) {
 563                 syslog(LOG_ERR, "CTRL: socketpair() error");
 564                 syslog_perror("socketpair");
 565                 exit(1);
 566         }
 567         tty_fd = sockfd[0];
 568         pty_fd = sockfd[1];
 569 #else
 570         /* Finds an open pty/tty pair */
 571         if (openpty(&pty_fd, &tty_fd, NULL, NULL, NULL) != 0) {
 572                 syslog(LOG_ERR, "CTRL: openpty() error");
 573                 syslog_perror("openpty");
 574                 exit(1);
 575         } else {
 576                 struct termios tios;
 577
 578                 /* Turn off echo in the slave - to prevent loopback.
 579                    pppd will do this, but might not do it before we
 580                    try to send data. */
 581                 if (tcgetattr(tty_fd, &tios) < 0) {
 582                         syslog(LOG_ERR, "CTRL: tcgetattr() error");
 583                         syslog_perror("tcgetattr");
 584                         exit(1);
 585                 }
 586                 tios.c_lflag &= ~(ECHO | ECHONL);
 587                 if (tcsetattr(tty_fd, TCSAFLUSH, &tios) < 0) {
 588                         syslog(LOG_ERR, "CTRL: tcsetattr() error");
 589                         syslog_perror("tcsetattr");
 590                         exit(1);
 591                 }
 592         }
 593 #endif
 594         if (pptpctrl_debug) {
 595                 syslog(LOG_DEBUG, "CTRL: pty_fd = %d", pty_fd);
 596                 syslog(LOG_DEBUG, "CTRL: tty_fd = %d", tty_fd);
 597         }
 598         /* Launch the PPPD  */
 599 #ifndef HAVE_FORK
 600         switch(pppfork=vfork()){
 601 #else
 602         switch(pppfork=fork()){
 603 #endif
 604         case -1:        /* fork() error */
 605                 syslog(LOG_ERR, "CTRL: Error forking to exec pppd");
 606                 _exit(1);
 607
 608         case 0:         /* child */
 609                 if (dup2(tty_fd, 0) == -1) {
 610                   syslog(LOG_ERR, "CTRL: child tty_fd dup2 to stdin, %s",
 611                          strerror(errno));
 612                   exit(1);
 613                 }
 614                 if (dup2(tty_fd, 1) == -1) {
 615                   syslog(LOG_ERR, "CTRL: child tty_fd dup2 to stdout, %s",
 616                          strerror(errno));
 617                   exit(1);
 618                 }
 619 #if 0
 620                 /* This must never be used if !HAVE_SYSLOG since that logs to stderr.
 621                  * Trying just never using it to see if it causes anyone else problems.
 622                  * It may let people see the pppd errors, which would be good.
 623                  */
 624                 dup2(tty_fd, 2);
 625 #endif
 626                 if (tty_fd > 1)
 627                         close(tty_fd);
 628                 if (pty_fd > 1)
 629                         close(pty_fd);
 630 /* In case we move clientSocket back off stdin */
 631 #ifndef clientSocket
 632                 if (clientSocket > 1)
 633                         close(clientSocket);
 634 #elif clientSocket > 1
 635                 close(clientSocket);
 636 #endif
 637                 launch_pppd(pppaddrs, inetaddrs);
 638                 syslog(LOG_ERR, "CTRL: PPPD launch failed! (launch_pppd did not fork)");
 639                 _exit(1);
 640         }
 641
 642         close(tty_fd);
 643         return pty_fd;
 644 }
 645
 646 /*
 647  * launch_pppd
 648  *
 649  * Launches the PPP daemon. The PPP daemon is responsible for assigning the
 650  * PPTP client its IP address.. These values are assigned via the command
 651  * line.
 652  *
 653  * Add return of connected ppp interface
 654  *
 655  * retn: 0 on success, -1 on failure.
 656  *
 657  */
 658 static void launch_pppd(char **pppaddrs, struct in_addr *inetaddrs)
 659 {
 660         char *pppd_argv[14];
 661         int an = 0;
 662         sigset_t sigs;
 663
 664         pppd_argv[an++] = ppp_binary;
 665
 666         if (pptpctrl_debug) {
 667                 syslog(LOG_DEBUG,
 668                        "CTRL (PPPD Launcher): program binary = %s",
 669                        pppd_argv[an - 1]);
 670         }
 671
 672 #if BSDUSER_PPP
 673
 674         /* The way that Brian Somers' user-land ppp works is to use the
 675          * system name as a reference for most of the useful options. Hence
 676          * most things can't be defined on the command line. On OpenBSD at
 677          * least the file used for the systems is /etc/ppp/ppp.conf, where
 678          * the pptp stanza should look something like:
 679
 680          pptp:
 681          set speed sync
 682          enable pap
 683          enable chap
 684          set dns a.a.a.a b.b.b.b
 685          set ndbs x.x.x.x y.y.y.y
 686          accept dns
 687          add 10.0.0/24
 688
 689          * To be honest, at the time of writing, I haven't had the thing
 690          * working enough to understand :) I will update this comment and
 691          * make a sample config available when I get there.
 692          */
 693
 694         /* options for BSDUSER_PPP
 695          *
 696          * ignores IP addresses, config file option, speed
 697          * fix usage info in pptpd.c and configure script if this changes
 698          *
 699          * IP addresses can be specified in /etc/ppp/ppp.secret per user
 700          */
 701         pppd_argv[an++] = "-direct";
 702         pppd_argv[an++] = "pptp";       /* XXX this is the system name */
 703         /* should be dynamic - PMG */
 704
 705 #elif SLIRP
 706
 707         /* options for SLIRP
 708          *
 709          * ignores IP addresses from config - SLIRP handles this
 710          */
 711         pppd_argv[an++] = "-P";
 712         pppd_argv[an++] = "+chap";
 713         pppd_argv[an++] = "-b";
 714
 715         /* If a speed has been specified, use it
 716          * if not, use "smart" default (defaults.h)
 717          */
 718         if (*speed) {
 719                 pppd_argv[an++] = speed;
 720         } else {
 721                 pppd_argv[an++] = PPP_SPEED_DEFAULT;
 722         }
 723
 724         if (*pppdxfig) {
 725                 pppd_argv[an++] = "-f";
 726                 pppd_argv[an++] = pppdxfig;
 727         }
 728
 729         if (pptpctrl_debug) {
 730                 syslog(LOG_DEBUG, "CTRL (PPPD Launcher): Connection speed = %s", pppd_argv[an - 1]);
 731         }
 732 #else
 733
 734         /* options for 'normal' pppd */
 735
 736         pppd_argv[an++] = "local";
 737
 738         /* If a pppd option file is specified, use it
 739          * if not, pppd will default to /etc/ppp/options
 740          */
 741         if (*pppdxfig) {
 742                 pppd_argv[an++] = "file";
 743                 pppd_argv[an++] = pppdxfig;
 744         }
 745
 746         /* If a speed has been specified, use it
 747          * if not, use "smart" default (defaults.h)
 748          */
 749         if (*speed) {
 750                 pppd_argv[an++] = speed;
 751         } else {
 752                 pppd_argv[an++] = PPP_SPEED_DEFAULT;
 753         }
 754
 755         if (pptpctrl_debug) {
 756                 if (*pppaddrs[0])
 757                         syslog(LOG_DEBUG, "CTRL (PPPD Launcher): local address = %s", pppaddrs[0]);
 758                 if (*pppaddrs[1])
 759                         syslog(LOG_DEBUG, "CTRL (PPPD Launcher): remote address = %s", pppaddrs[1]);
 760         }
 761
 762         if (*pppaddrs[0] || *pppaddrs[1]) {
 763                 char pppInterfaceIPs[33];
 764                 sprintf(pppInterfaceIPs, "%s:%s", pppaddrs[0], pppaddrs[1]);
 765                 pppd_argv[an++] = pppInterfaceIPs;
 766         }
 767 #endif
 768
 769         if (!noipparam) {
 770                  pppd_argv[an++] = "ipparam";
 771                  pppd_argv[an++] = inet_ntoa(inetaddrs[1]);
 772         }
 773
 774         if (pptp_logwtmp) {
 775                  pppd_argv[an++] = "plugin";
 776                  pppd_argv[an++] = "/usr/lib/pptpd/pptpd-logwtmp.so";
 777                  pppd_argv[an++] = "pptpd-original-ip";
 778                  pppd_argv[an++] = inet_ntoa(inetaddrs[1]);
 779         }
 780
 781         /* argv arrays must always be NULL terminated */
 782         pppd_argv[an++] = NULL;
 783         /* make sure SIGCHLD is unblocked, pppd does not expect it */
 784         sigfillset(&sigs);
 785         sigprocmask(SIG_UNBLOCK, &sigs, NULL);
 786         /* run pppd now */
 787         execvp(pppd_argv[0], pppd_argv);
 788         /* execvp() failed */
 789         syslog(LOG_ERR,
 790                "CTRL (PPPD Launcher): Failed to launch PPP daemon. %s",
 791                strerror(errno));
 792 }
 793