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 = 0;
  47 static int curpts = 0;
  48 static int pts_valid = 0;
  49 static size_t lbsize;
  50 static char *line;
  51
  52 #define PTS "pts/"
  53 #define MALLOCCHUNK     100
  54
  55 static char *skip(char *);
  56 static char *value(char *);
  57
  58 struct ttyent *
  59 getttynam(tty)
  60         const char *tty;
  61 {
  62         struct ttyent *t;
  63
  64         if (strncmp(tty, "/dev/", 5) == 0)
  65                 tty += 5;
  66         setttyent();
  67         while ( (t = getttyent()) )
  68                 if (!strcmp(tty, t->ty_name))
  69                         break;
  70         endttyent();
  71         return (t);
  72 }
  73
  74 struct ttyent *
  75 getttyent()
  76 {
  77         static struct ttyent tty;
  78         static char devpts_name[] = "pts/4294967295";
  79         char *p;
  80         int c;
  81         size_t i;
  82
  83         if (!tf && !setttyent())
  84                 return (NULL);
  85         for (;;) {
  86                 if (!fgets(p = line, lbsize, tf)) {
  87                         if (pts_valid == 1 && curpts <= maxpts) {
  88                                 sprintf(devpts_name, "pts/%d", curpts++);
  89                                 tty.ty_name = devpts_name;
  90                                 tty.ty_getty = tty.ty_type = NULL;
  91                                 tty.ty_status = TTY_NETWORK;
  92                                 tty.ty_window = NULL;
  93                                 tty.ty_comment = NULL;
  94                                 tty.ty_group  = _TTYS_NOGROUP;
  95                                 return (&tty);
  96                         }
  97                         return (NULL);
  98                 }
  99                 /* extend buffer if line was too big, and retry */
 100                 while (!index(p, '\n')) {
 101                         i = strlen(p);
 102                         lbsize += MALLOCCHUNK;
 103                         if ((p = realloc(line, lbsize)) == NULL) {
 104                                 (void)endttyent();
 105                                 return (NULL);
 106                         }
 107                         line = p;
 108                         if (!fgets(&line[i], lbsize - i, tf))
 109                                 return (NULL);
 110                 }
 111                 while (isspace((unsigned char)*p))
 112                         ++p;
 113                 if (*p && *p != '#')
 114                         break;
 115         }
 116
 117 #define scmp(e) !strncmp(p, e, sizeof(e) - 1) && isspace((unsigned char)p[sizeof(e) - 1])
 118 #define vcmp(e) !strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
 119
 120         zapchar = 0;
 121         tty.ty_name = p;
 122         tty.ty_status = 0;
 123         tty.ty_window = NULL;
 124         tty.ty_group  = _TTYS_NOGROUP;
 125
 126         p = skip(p);
 127         if (!*(tty.ty_getty = p))
 128                 tty.ty_getty = tty.ty_type = NULL;
 129         else {
 130                 p = skip(p);
 131                 if (!*(tty.ty_type = p))
 132                         tty.ty_type = NULL;
 133                 else {
 134                         /* compatibility kludge: handle network/dialup specially */
 135                         if (scmp(_TTYS_DIALUP))
 136                                 tty.ty_status |= TTY_DIALUP;
 137                         else if (scmp(_TTYS_NETWORK))
 138                                 tty.ty_status |= TTY_NETWORK;
 139                         p = skip(p);
 140                 }
 141         }
 142
 143         for (; *p; p = skip(p)) {
 144                 if (scmp(_TTYS_OFF))
 145                         tty.ty_status &= ~TTY_ON;
 146                 else if (scmp(_TTYS_ON))
 147                         tty.ty_status |= TTY_ON;
 148                 else if (scmp(_TTYS_SECURE))
 149                         tty.ty_status |= TTY_SECURE;
 150                 else if (scmp(_TTYS_INSECURE))
 151                         tty.ty_status &= ~TTY_SECURE;
 152                 else if (scmp(_TTYS_DIALUP))
 153                         tty.ty_status |= TTY_DIALUP;
 154                 else if (scmp(_TTYS_NETWORK))
 155                         tty.ty_status |= TTY_NETWORK;
 156                 else if (vcmp(_TTYS_WINDOW))
 157                         tty.ty_window = value(p);
 158                 else if (vcmp(_TTYS_GROUP))
 159                         tty.ty_group = value(p);
 160                 else
 161                         break;
 162         }
 163
 164         if (zapchar == '#' || *p == '#')
 165                 while ((c = *++p) == ' ' || c == '\t')
 166                         ;
 167         tty.ty_comment = p;
 168         if (*p == 0)
 169                 tty.ty_comment = 0;
 170         if ( (p = index(p, '\n')) )
 171                 *p = '\0';
 172         return (&tty);
 173 }
 174
 175 #define QUOTED  1
 176
 177 /*
 178  * Skip over the current field, removing quotes, and return a pointer to
 179  * the next field.
 180  */
 181 static char *
 182 skip(p)
 183         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(p)
 217         char *p;
 218 {
 219
 220         return ((p = index(p, '=')) ? ++p : NULL);
 221 }
 222
 223 int
 224 setttyent()
 225 {
 226         DIR *devpts_dir;
 227
 228         if (line == NULL) {
 229                 if ((line = malloc(MALLOCCHUNK)) == NULL)
 230                         return (0);
 231                 lbsize = MALLOCCHUNK;
 232         }
 233         devpts_dir = opendir(_PATH_DEV PTS);
 234         if (devpts_dir) {
 235                 struct dirent *dp;
 236
 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                                         pts_valid = 1;
 243                                         curpts = 0;
 244                                 }
 245                         }
 246                 }
 247                 closedir(devpts_dir);
 248         }
 249         if (tf) {
 250                 rewind(tf);
 251                 return (1);
 252         } else if ( (tf = fopen(_PATH_TTYS, "r")) )
 253                 return (1);
 254         return (0);
 255 }
 256
 257 int
 258 endttyent()
 259 {
 260         int rval;
 261
 262         pts_valid = 0;
 263         /*
 264          * NB: Don't free `line' because getttynam()
 265          * may still be referencing it
 266          */
 267         if (tf) {
 268                 rval = (fclose(tf) != EOF);
 269                 tf = NULL;
 270                 return (rval);
 271         }
 272         return (1);
 273 }
 274
 275 static int
 276 isttystat(tty, flag)
 277         const char *tty;
 278         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(tty)
 288         const char *tty;
 289 {
 290
 291         return isttystat(tty, TTY_DIALUP);
 292 }
 293
 294 int isnettty(tty)
 295         const char *tty;
 296 {
 297
 298         return isttystat(tty, TTY_NETWORK);
 299 }