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  * 4. 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
  30 #if defined(LIBC_SCCS) && !defined(lint)
  31 static char sccsid[] = "@(#)getttyent.c 8.1 (Berkeley) 6/4/93";
  32 #endif /* LIBC_SCCS and not lint */
  33 #include <sys/cdefs.h>
  34 __FBSDID("$FreeBSD$");
  35
  36 #include <ttyent.h>
  37 #include <stdio.h>
  38 #include <stdlib.h>
  39 #include <ctype.h>
  40 #include <string.h>
  41 #include <dirent.h>
  42 #include <paths.h>
  43
  44 static char zapchar;
  45 static FILE *tf;
  46 static int maxpts = -1;
  47 static int curpts = 0;
  48 static size_t lbsize;
  49 static char *line;
  50
  51 #define PTS "pts/"
  52 #define MALLOCCHUNK     100
  53
  54 static char *skip(char *);
  55 static char *value(char *);
  56
  57 struct ttyent *
  58 getttynam(tty)
  59         const char *tty;
  60 {
  61         struct ttyent *t;
  62
  63         if (strncmp(tty, "/dev/", 5) == 0)
  64                 tty += 5;
  65         setttyent();
  66         while ( (t = getttyent()) )
  67                 if (!strcmp(tty, t->ty_name))
  68                         break;
  69         endttyent();
  70         return (t);
  71 }
  72
  73 struct ttyent *
  74 getttyent()
  75 {
  76         static struct ttyent tty;
  77         static char devpts_name[] = "pts/4294967295";
  78         char *p;
  79         int c;
  80         size_t i;
  81
  82         if (!tf && !setttyent())
  83                 return (NULL);
  84         for (;;) {
  85                 if (!fgets(p = line, lbsize, tf)) {
  86                         if (curpts <= maxpts) {
  87                                 sprintf(devpts_name, "pts/%d", curpts++);
  88                                 tty.ty_name = devpts_name;
  89                                 tty.ty_getty = tty.ty_type = NULL;
  90                                 tty.ty_status = TTY_NETWORK;
  91                                 tty.ty_window = NULL;
  92                                 tty.ty_comment = NULL;
  93                                 tty.ty_group  = _TTYS_NOGROUP;
  94                                 return (&tty);
  95                         }
  96                         return (NULL);
  97                 }
  98                 /* extend buffer if line was too big, and retry */
  99                 while (!index(p, '\n') && !feof(tf)) {
 100                         i = strlen(p);
 101                         lbsize += MALLOCCHUNK;
 102                         if ((p = realloc(line, lbsize)) == NULL) {
 103                                 (void)endttyent();
 104                                 return (NULL);
 105                         }
 106                         line = p;
 107                         if (!fgets(&line[i], lbsize - i, tf))
 108                                 return (NULL);
 109                 }
 110                 while (isspace((unsigned char)*p))
 111                         ++p;
 112                 if (*p && *p != '#')
 113                         break;
 114         }
 115
 116 #define scmp(e) !strncmp(p, e, sizeof(e) - 1) && isspace((unsigned char)p[sizeof(e) - 1])
 117 #define vcmp(e) !strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
 118
 119         zapchar = 0;
 120         tty.ty_name = p;
 121         tty.ty_status = 0;
 122         tty.ty_window = NULL;
 123         tty.ty_group  = _TTYS_NOGROUP;
 124
 125         p = skip(p);
 126         if (!*(tty.ty_getty = p))
 127                 tty.ty_getty = tty.ty_type = NULL;
 128         else {
 129                 p = skip(p);
 130                 if (!*(tty.ty_type = p))
 131                         tty.ty_type = NULL;
 132                 else {
 133                         /* compatibility kludge: handle network/dialup specially */
 134                         if (scmp(_TTYS_DIALUP))
 135                                 tty.ty_status |= TTY_DIALUP;
 136                         else if (scmp(_TTYS_NETWORK))
 137                                 tty.ty_status |= TTY_NETWORK;
 138                         p = skip(p);
 139                 }
 140         }
 141
 142         for (; *p; p = skip(p)) {
 143                 if (scmp(_TTYS_OFF))
 144                         tty.ty_status &= ~TTY_ON;
 145                 else if (scmp(_TTYS_ON))
 146                         tty.ty_status |= TTY_ON;
 147                 else if (scmp(_TTYS_SECURE))
 148                         tty.ty_status |= TTY_SECURE;
 149                 else if (scmp(_TTYS_INSECURE))
 150                         tty.ty_status &= ~TTY_SECURE;
 151                 else if (scmp(_TTYS_DIALUP))
 152                         tty.ty_status |= TTY_DIALUP;
 153                 else if (scmp(_TTYS_NETWORK))
 154                         tty.ty_status |= TTY_NETWORK;
 155                 else if (vcmp(_TTYS_WINDOW))
 156                         tty.ty_window = value(p);
 157                 else if (vcmp(_TTYS_GROUP))
 158                         tty.ty_group = value(p);
 159                 else
 160                         break;
 161         }
 162
 163         if (zapchar == '#' || *p == '#')
 164                 while ((c = *++p) == ' ' || c == '\t')
 165                         ;
 166         tty.ty_comment = p;
 167         if (*p == 0)
 168                 tty.ty_comment = 0;
 169         if ( (p = index(p, '\n')) )
 170                 *p = '\0';
 171         return (&tty);
 172 }
 173
 174 #define QUOTED  1
 175
 176 /*
 177  * Skip over the current field, removing quotes, and return a pointer to
 178  * the next field.
 179  */
 180 static char *
 181 skip(p)
 182         char *p;
 183 {
 184         char *t;
 185         int c, q;
 186
 187         for (q = 0, t = p; (c = *p) != '\0'; p++) {
 188                 if (c == '"') {
 189                         q ^= QUOTED;    /* obscure, but nice */
 190                         continue;
 191                 }
 192                 if (q == QUOTED && *p == '\\' && *(p+1) == '"')
 193                         p++;
 194                 *t++ = *p;
 195                 if (q == QUOTED)
 196                         continue;
 197                 if (c == '#') {
 198                         zapchar = c;
 199                         *p = 0;
 200                         break;
 201                 }
 202                 if (c == '\t' || c == ' ' || c == '\n') {
 203                         zapchar = c;
 204                         *p++ = 0;
 205                         while ((c = *p) == '\t' || c == ' ' || c == '\n')
 206                                 p++;
 207                         break;
 208                 }
 209         }
 210         *--t = '\0';
 211         return (p);
 212 }
 213
 214 static char *
 215 value(p)
 216         char *p;
 217 {
 218
 219         return ((p = index(p, '=')) ? ++p : NULL);
 220 }
 221
 222 int
 223 setttyent()
 224 {
 225         DIR *devpts_dir;
 226
 227         if (line == NULL) {
 228                 if ((line = malloc(MALLOCCHUNK)) == NULL)
 229                         return (0);
 230                 lbsize = MALLOCCHUNK;
 231         }
 232         devpts_dir = opendir(_PATH_DEV PTS);
 233         if (devpts_dir) {
 234                 struct dirent *dp;
 235
 236                 maxpts = -1;
 237                 while ((dp = readdir(devpts_dir))) {
 238                         if (strcmp(dp->d_name, ".") != 0 &&
 239                             strcmp(dp->d_name, "..") != 0) {
 240                                 if (atoi(dp->d_name) > maxpts) {
 241                                         maxpts = atoi(dp->d_name);
 242                                         curpts = 0;
 243                                 }
 244                         }
 245                 }
 246                 closedir(devpts_dir);
 247         }
 248         if (tf) {
 249                 rewind(tf);
 250                 return (1);
 251         } else if ( (tf = fopen(_PATH_TTYS, "r")) )
 252                 return (1);
 253         return (0);
 254 }
 255
 256 int
 257 endttyent()
 258 {
 259         int rval;
 260
 261         maxpts = -1;
 262         /*
 263          * NB: Don't free `line' because getttynam()
 264          * may still be referencing it
 265          */
 266         if (tf) {
 267                 rval = (fclose(tf) != EOF);
 268                 tf = NULL;
 269                 return (rval);
 270         }
 271         return (1);
 272 }
 273
 274 static int
 275 isttystat(tty, flag)
 276         const char *tty;
 277         int flag;
 278 {
 279         struct ttyent *t;
 280
 281         return ((t = getttynam(tty)) == NULL) ? 0 : !!(t->ty_status & flag);
 282 }
 283
 284
 285 int
 286 isdialuptty(tty)
 287         const char *tty;
 288 {
 289
 290         return isttystat(tty, TTY_DIALUP);
 291 }
 292
 293 int isnettty(tty)
 294         const char *tty;
 295 {
 296
 297         return isttystat(tty, TTY_NETWORK);
 298 }