lib/libc/gen/getttyent.c

   1 /*
   2  * Copyright (c) 1989, 1993
   3  *      The Regents of the University of California.  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  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  *
  29  * $FreeBSD: src/lib/libc/gen/getttyent.c,v 1.13 2005/07/25 17:57:15 mdodd Exp $
  30  *
  31  * @(#)getttyent.c      8.1 (Berkeley) 6/4/93
  32  */
  33
  34 #include <ttyent.h>
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <ctype.h>
  38 #include <string.h>
  39 #include <dirent.h>
  40 #include <paths.h>
  41
  42 static char zapchar;
  43 static FILE *tf;
  44 static int maxpts = -1;
  45 static int curpts = 0;
  46 static size_t lbsize;
  47 static char *line;
  48
  49 #define PTS     "pts/"
  50 #define MALLOCCHUNK     100
  51
  52 static char *skip (char *);
  53 static char *value (char *);
  54
  55 struct ttyent *
  56 getttynam(const char *tty)
  57 {
  58         struct ttyent *t;
  59
  60         if (strncmp(tty, "/dev/", 5) == 0)
  61                 tty += 5;
  62         setttyent();
  63         while ( (t = getttyent()) )
  64                 if (!strcmp(tty, t->ty_name))
  65                         break;
  66         endttyent();
  67         return (t);
  68 }
  69
  70 struct ttyent *
  71 getttyent(void)
  72 {
  73         static struct ttyent tty;
  74         static char devpts_name[] = "pts/9999999999";
  75         char *p;
  76         int c;
  77         size_t i;
  78
  79         if (!tf && !setttyent())
  80                 return (NULL);
  81         for (;;) {
  82                 if (!fgets(p = line, lbsize, tf)) {
  83                         if (curpts <= maxpts) {
  84                                 sprintf(devpts_name, "pts/%d", curpts++);
  85                                 tty.ty_name = devpts_name;
  86                                 tty.ty_getty = NULL;
  87                                 tty.ty_type = NULL;
  88                                 tty.ty_status = TTY_NETWORK;
  89                                 tty.ty_window = NULL;
  90                                 tty.ty_comment = NULL;
  91                                 tty.ty_group = _TTYS_NOGROUP;
  92                                 return (&tty);
  93                         }
  94                         return (NULL);
  95                 }
  96                 /* extend buffer if line was too big, and retry */
  97                 while (!index(p, '\n') && !feof(tf)) {
  98                         i = strlen(p);
  99                         lbsize += MALLOCCHUNK;
 100                         if ((p = realloc(line, lbsize)) == NULL) {
 101                                 endttyent();
 102                                 return (NULL);
 103                         }
 104                         line = p;
 105                         if (!fgets(&line[i], lbsize - i, tf))
 106                                 return (NULL);
 107                 }
 108                 while (isspace((unsigned char)*p))
 109                         ++p;
 110                 if (*p && *p != '#')
 111                         break;
 112         }
 113
 114 #define scmp(e) !strncmp(p, e, sizeof(e) - 1) && isspace((unsigned char)p[sizeof(e) - 1])
 115 #define vcmp(e) !strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
 116
 117         zapchar = 0;
 118         tty.ty_name = p;
 119         tty.ty_status = 0;
 120         tty.ty_window = NULL;
 121         tty.ty_group  = _TTYS_NOGROUP;
 122
 123         p = skip(p);
 124         if (!*(tty.ty_getty = p))
 125                 tty.ty_getty = tty.ty_type = NULL;
 126         else {
 127                 p = skip(p);
 128                 if (!*(tty.ty_type = p))
 129                         tty.ty_type = NULL;
 130                 else {
 131                         /* compatibility kludge: handle network/dialup specially */
 132                         if (scmp(_TTYS_DIALUP))
 133                                 tty.ty_status |= TTY_DIALUP;
 134                         else if (scmp(_TTYS_NETWORK))
 135                                 tty.ty_status |= TTY_NETWORK;
 136                         p = skip(p);
 137                 }
 138         }
 139
 140         for (; *p; p = skip(p)) {
 141                 if (scmp(_TTYS_OFF))
 142                         tty.ty_status &= ~TTY_ON;
 143                 else if (scmp(_TTYS_ON))
 144                         tty.ty_status |= TTY_ON;
 145                 else if (scmp(_TTYS_SECURE))
 146                         tty.ty_status |= TTY_SECURE;
 147                 else if (scmp(_TTYS_INSECURE))
 148                         tty.ty_status &= ~TTY_SECURE;
 149                 else if (scmp(_TTYS_DIALUP))
 150                         tty.ty_status |= TTY_DIALUP;
 151                 else if (scmp(_TTYS_NETWORK))
 152                         tty.ty_status |= TTY_NETWORK;
 153                 else if (scmp(_TTYS_IFCONSOLE))
 154                         tty.ty_status |= TTY_IFCONSOLE;
 155                 else if (scmp(_TTYS_IFEXISTS))
 156                         tty.ty_status |= TTY_IFEXISTS;
 157                 else if (vcmp(_TTYS_WINDOW))
 158                         tty.ty_window = value(p);
 159                 else if (vcmp(_TTYS_GROUP))
 160                         tty.ty_group = value(p);
 161                 else
 162                         break;
 163         }
 164
 165         if (zapchar == '#' || *p == '#')
 166                 while ((c = *++p) == ' ' || c == '\t')
 167                         ;
 168         tty.ty_comment = p;
 169         if (*p == 0)
 170                 tty.ty_comment = 0;
 171         if ( (p = index(p, '\n')) )
 172                 *p = '\0';
 173         return (&tty);
 174 }
 175
 176 #define QUOTED  1
 177
 178 /*
 179  * Skip over the current field, removing quotes, and return a pointer to
 180  * the next field.
 181  */
 182 static char *
 183 skip(char *p)
 184 {
 185         char *t;
 186         int c, q;
 187
 188         for (q = 0, t = p; (c = *p) != '\0'; p++) {
 189                 if (c == '"') {
 190                         q ^= QUOTED;    /* obscure, but nice */
 191                         continue;
 192                 }
 193                 if (q == QUOTED && *p == '\\' && *(p+1) == '"')
 194                         p++;
 195                 *t++ = *p;
 196                 if (q == QUOTED)
 197                         continue;
 198                 if (c == '#') {
 199                         zapchar = c;
 200                         *p = 0;
 201                         break;
 202                 }
 203                 if (c == '\t' || c == ' ' || c == '\n') {
 204                         zapchar = c;
 205                         *p++ = 0;
 206                         while ((c = *p) == '\t' || c == ' ' || c == '\n')
 207                                 p++;
 208                         break;
 209                 }
 210         }
 211         *--t = '\0';
 212         return (p);
 213 }
 214
 215 static char *
 216 value(char *p)
 217 {
 218
 219         return ((p = index(p, '=')) ? ++p : NULL);
 220 }
 221
 222 int
 223 setttyent(void)
 224 {
 225         DIR *devpts_dir;
 226         struct dirent *dp;
 227         int unit;
 228
 229         if (line == NULL) {
 230                 if ((line = malloc(MALLOCCHUNK)) == NULL)
 231                         return (0);
 232                 lbsize = MALLOCCHUNK;
 233         }
 234         devpts_dir = opendir(_PATH_DEV PTS);
 235         if (devpts_dir) {
 236                 maxpts = -1;
 237                 while ((dp = readdir(devpts_dir))) {
 238                         if (strcmp(dp->d_name, ".") == 0 ||
 239                             strcmp(dp->d_name, "..") == 0)
 240                                 continue;
 241
 242                         unit = (int)strtol(dp->d_name, NULL, 10);
 243
 244                         if (unit > maxpts) {
 245                                 maxpts = unit;
 246                                 curpts = 0;
 247                         }
 248                 }
 249                 closedir(devpts_dir);
 250         }
 251         if (tf) {
 252                 rewind(tf);
 253                 return (1);
 254         } else if ( (tf = fopen(_PATH_TTYS, "r")) )
 255                 return (1);
 256         return (0);
 257 }
 258
 259 int
 260 endttyent(void)
 261 {
 262         int rval;
 263
 264         maxpts = -1;
 265         /*
 266          * NB: Don't free `line' because getttynam()
 267          * may still be referencing it
 268          */
 269         if (tf) {
 270                 rval = (fclose(tf) != EOF);
 271                 tf = NULL;
 272                 return (rval);
 273         }
 274         return (1);
 275 }
 276
 277 static int
 278 isttystat(const char *tty, int flag)
 279 {
 280         struct ttyent *t;
 281
 282         return ((t = getttynam(tty)) == NULL) ? 0 : !!(t->ty_status & flag);
 283 }
 284
 285
 286 int
 287 isdialuptty(const char *tty)
 288 {
 289
 290         return isttystat(tty, TTY_DIALUP);
 291 }
 292
 293 int
 294 isnettty(const char *tty)
 295 {
 296
 297         return isttystat(tty, TTY_NETWORK);
 298 }