release/src/router/xl2tpd/pty.c

   1 /*
   2  * Layer Two Tunnelling Protocol Daemon
   3  * Copyright (C) 1998 Adtran, Inc.
   4  * Copyright (C) 2002 Jeff McAdams
   5  *
   6  * Mark Spencer
   7  *
   8  * This software is distributed under the terms
   9  * of the GPL, which you should have received
  10  * along with this source.
  11  *
  12  * Pseudo-pty allocation routines...  Concepts and code borrowed
  13  * from pty-redir by Magosanyi Arpad.
  14  *
  15  */
  16
  17 #define _ISOC99_SOURCE
  18 #define _XOPEN_SOURCE
  19 #define _BSD_SOURCE
  20 #define _XOPEN_SOURCE_EXTENDED
  21
  22 #include <stdlib.h>
  23 #include <unistd.h>
  24 #include <string.h>
  25 #include <errno.h>
  26 #include <stdio.h>
  27 #include <fcntl.h>
  28 #include "l2tp.h"
  29
  30
  31
  32 #ifdef SOLARIS
  33 #define PTY00 "/dev/ptyXX"
  34 #define PTY10 "pqrstuvwxyz"
  35 #define PTY01 "0123456789abcdef"
  36 #endif
  37
  38 #ifdef LINUX
  39 #define PTY00 "/dev/ptyXX"
  40 #define PTY10 "pqrstuvwxyzabcde"
  41 #define PTY01 "0123456789abcdef"
  42 #endif
  43
  44 #ifdef FREEBSD
  45 #define PTY00 "/dev/ptyXX"
  46 #define PTY10 "p"
  47 #define PTY01 "0123456789abcdefghijklmnopqrstuv"
  48 #endif
  49
  50 #ifndef OPENBSD
  51 int getPtyMaster_pty (char *tty10, char *tty01)
  52 {
  53     char *p10;
  54     char *p01;
  55     static char dev[] = PTY00;
  56     int fd;
  57
  58     for (p10 = PTY10; *p10; p10++)
  59     {
  60         dev[8] = *p10;
  61         for (p01 = PTY01; *p01; p01++)
  62         {
  63             dev[9] = *p01;
  64             fd = open (dev, O_RDWR | O_NONBLOCK);
  65             if (fd >= 0)
  66             {
  67                 *tty10 = *p10;
  68                 *tty01 = *p01;
  69                 return fd;
  70             }
  71         }
  72     }
  73     l2tp_log (LOG_CRIT, "%s: No more free pseudo-tty's\n", __FUNCTION__);
  74     return -1;
  75 }
  76
  77 int getPtyMaster_ptmx(char *ttybuf, int ttybuflen)
  78 {
  79     int fd;
  80     char *tty;
  81
  82     fd = open("/dev/ptmx", O_RDWR);
  83     if (fd == -1)
  84     {
  85         l2tp_log (LOG_WARNING, "%s: unable to open /dev/ptmx to allocate pty\n",
  86                   __FUNCTION__);
  87         return -EINVAL;
  88     }
  89
  90     /* change the onwership */
  91     if (grantpt(fd))
  92     {
  93         l2tp_log (LOG_WARNING, "%s: unable to grantpt() on pty\n",
  94                   __FUNCTION__);
  95         close(fd);
  96         return -EINVAL;
  97     }
  98
  99     if (unlockpt(fd))
 100     {
 101         l2tp_log (LOG_WARNING, "%s: unable to unlockpt() on pty\n",
 102                   __FUNCTION__);
 103         close(fd);
 104         return -EINVAL;
 105     }
 106
 107     tty = ptsname(fd);
 108     if (tty == NULL)
 109     {
 110         l2tp_log (LOG_WARNING, "%s: unable to obtain name of slave tty\n",
 111                   __FUNCTION__);
 112         close(fd);
 113         return -EINVAL;
 114     }
 115     ttybuf[0]='\0';
 116     strncat(ttybuf, tty, ttybuflen);
 117
 118     return fd;
 119 }
 120 #endif
 121 #ifdef OPENBSD
 122 int getPtyMaster_ptm(char *ttybuf, int ttybuflen)
 123 {
 124     int amaster, aslave;
 125     char *tty = (char*) malloc(64);
 126
 127     if((openpty(&amaster, &aslave, tty, NULL, NULL)) == -1)
 128     {
 129         l2tp_log (LOG_WARNING, "%s: openpty() returned %s\n",
 130                 __FUNCTION__, strerror(errno));
 131         free(tty);
 132         return -EINVAL;
 133     }
 134
 135     ttybuf[0] = '\0';
 136     strncat(ttybuf, tty, ttybuflen);
 137
 138     free(tty);
 139
 140     return amaster;
 141 }
 142 #endif /* OPENBSD */
 143
 144 int getPtyMaster(char *ttybuf, int ttybuflen)
 145 {
 146     int fd;
 147 #ifndef OPENBSD
 148     fd = getPtyMaster_ptmx(ttybuf, ttybuflen);
 149     char a, b;
 150
 151     if(fd >= 0) {
 152         return fd;
 153     }
 154
 155     l2tp_log (LOG_WARNING, "%s: failed to use pts -- using legacy ptys\n", __FUNCTION__);
 156     fd = getPtyMaster_pty(&a,&b);
 157
 158     if(fd >= 0) {
 159         snprintf(ttybuf, ttybuflen, "/dev/tty%c%c", a, b);
 160         return fd;
 161     }
 162 #endif
 163 #ifdef OPENBSD
 164
 165     fd = getPtyMaster_ptm(ttybuf, ttybuflen);
 166     if(fd >= 0) {
 167         return fd;
 168     }
 169 #endif /* OPENBSD */
 170
 171     return -EINVAL;
 172 }