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. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35 static char sccsid[] = "@(#)getttyent.c 8.1 (Berkeley) 6/4/93";
  36 #endif /* LIBC_SCCS and not lint */
  37 #include <sys/cdefs.h>
  38 __FBSDID("$FreeBSD$");
  39
  40 #include <ttyent.h>
  41 #include <stdio.h>
  42 #include <stdlib.h>
  43 #include <ctype.h>
  44 #include <string.h>
  45 #include <dirent.h>
  46 #include <paths.h>
  47
  48 static char zapchar;
  49 static FILE *tf;
  50 static int maxpts = 0;
  51 static int curpts = 0;
  52 static int pts_valid = 0;
  53 static size_t lbsize;
  54 static char *line;
  55
  56 #define PTS "pts/"
  57 #define MALLOCCHUNK     100
  58
  59 static char *skip(char *);
  60 static char *value(char *);
  61
  62 struct ttyent *
  63 getttynam(tty)
  64         const char *tty;
  65 {
  66         struct ttyent *t;
  67
  68         if (strncmp(tty, "/dev/", 5) == 0)
  69                 tty += 5;
  70         setttyent();
  71         while ( (t = getttyent()) )
  72                 if (!strcmp(tty, t->ty_name))
  73                         break;
  74         endttyent();
  75         return (t);
  76 }
  77
  78 struct ttyent *
  79 getttyent()
  80 {
  81         static struct ttyent tty;
  82         static char devpts_name[] = "pts/4294967295";
  83         char *p;
  84         int c;
  85         size_t i;
  86
  87         if (!tf && !setttyent())
  88                 return (NULL);
  89         for (;;) {
  90                 if (!fgets(p = line, lbsize, tf)) {
  91                         if (pts_valid == 1 && curpts <= maxpts) {
  92                                 sprintf(devpts_name, "pts/%d", curpts++);
  93                                 tty.ty_name = devpts_name;
  94                                 tty.ty_getty = tty.ty_type = NULL;
  95                                 tty.ty_status = TTY_NETWORK;
  96                                 tty.ty_window = NULL;
  97                                 tty.ty_comment = NULL;
  98                                 tty.ty_group  = _TTYS_NOGROUP;
  99                                 return (&tty);
 100                         }
 101                         return (NULL);
 102                 }
 103                 /* extend buffer if line was too big, and retry */
 104                 while (!index(p, '\n')) {
 105                         i = strlen(p);
 106                         lbsize += MALLOCCHUNK;
 107                         if ((p = realloc(line, lbsize)) == NULL) {
 108                                 (void)endttyent();
 109                                 return (NULL);
 110                         }
 111                         line = p;
 112                         if (!fgets(&line[i], lbsize - i, tf))
 113                                 return (NULL);
 114                 }
 115                 while (isspace((unsigned char)*p))
 116                         ++p;
 117                 if (*p && *p != '#')
 118                         break;
 119         }
 120
 121 #define scmp(e) !strncmp(p, e, sizeof(e) - 1) && isspace((unsigned char)p[sizeof(e) - 1])
 122 #define vcmp(e) !strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
 123
 124         zapchar = 0;
 125         tty.ty_name = p;
 126         tty.ty_status = 0;
 127         tty.ty_window = NULL;
 128         tty.ty_group  = _TTYS_NOGROUP;
 129
 130         p = skip(p);
 131         if (!*(tty.ty_getty = p))
 132                 tty.ty_getty = tty.ty_type = NULL;
 133         else {
 134                 p = skip(p);
 135                 if (!*(tty.ty_type = p))
 136                         tty.ty_type = NULL;
 137                 else {
 138                         /* compatibility kludge: handle network/dialup specially */
 139                         if (scmp(_TTYS_DIALUP))
 140                                 tty.ty_status |= TTY_DIALUP;
 141                         else if (scmp(_TTYS_NETWORK))
 142                                 tty.ty_status |= TTY_NETWORK;
 143                         p = skip(p);
 144                 }
 145         }
 146
 147         for (; *p; p = skip(p)) {
 148                 if (scmp(_TTYS_OFF))
 149                         tty.ty_status &= ~TTY_ON;
 150                 else if (scmp(_TTYS_ON))
 151                         tty.ty_status |= TTY_ON;
 152                 else if (scmp(_TTYS_SECURE))
 153                         tty.ty_status |= TTY_SECURE;
 154                 else if (scmp(_TTYS_INSECURE))
 155                         tty.ty_status &= ~TTY_SECURE;
 156                 else if (scmp(_TTYS_DIALUP))
 157                         tty.ty_status |= TTY_DIALUP;
 158                 else if (scmp(_TTYS_NETWORK))
 159                         tty.ty_status |= TTY_NETWORK;
 160                 else if (vcmp(_TTYS_WINDOW))
 161                         tty.ty_window = value(p);
 162                 else if (vcmp(_TTYS_GROUP))
 163                         tty.ty_group = value(p);
 164                 else
 165                         break;
 166         }
 167
 168         if (zapchar == '#' || *p == '#')
 169                 while ((c = *++p) == ' ' || c == '\t')
 170                         ;
 171         tty.ty_comment = p;
 172         if (*p == 0)
 173                 tty.ty_comment = 0;
 174         if ( (p = index(p, '\n')) )
 175                 *p = '\0';
 176         return (&tty);
 177 }
 178
 179 #define QUOTED  1
 180
 181 /*
 182  * Skip over the current field, removing quotes, and return a pointer to
 183  * the next field.
 184  */
 185 static char *
 186 skip(p)
 187         char *p;
 188 {
 189         char *t;
 190         int c, q;
 191
 192         for (q = 0, t = p; (c = *p) != '\0'; p++) {
 193                 if (c == '"') {
 194                         q ^= QUOTED;    /* obscure, but nice */
 195                         continue;
 196                 }
 197                 if (q == QUOTED && *p == '\\' && *(p+1) == '"')
 198                         p++;
 199                 *t++ = *p;
 200                 if (q == QUOTED)
 201                         continue;
 202                 if (c == '#') {
 203                         zapchar = c;
 204                         *p = 0;
 205                         break;
 206                 }
 207                 if (c == '\t' || c == ' ' || c == '\n') {
 208                         zapchar = c;
 209                         *p++ = 0;
 210                         while ((c = *p) == '\t' || c == ' ' || c == '\n')
 211                                 p++;
 212                         break;
 213                 }
 214         }
 215         *--t = '\0';
 216         return (p);
 217 }
 218
 219 static char *
 220 value(p)
 221         char *p;
 222 {
 223
 224         return ((p = index(p, '=')) ? ++p : NULL);
 225 }
 226
 227 int
 228 setttyent()
 229 {
 230         DIR *devpts_dir;
 231
 232         if (line == NULL) {
 233                 if ((line = malloc(MALLOCCHUNK)) == NULL)
 234                         return (0);
 235                 lbsize = MALLOCCHUNK;
 236         }
 237         devpts_dir = opendir(_PATH_DEV PTS);
 238         if (devpts_dir) {
 239                 struct dirent *dp;
 240
 241                 while ((dp = readdir(devpts_dir))) {
 242                         if (strcmp(dp->d_name, ".") != 0 &&
 243                             strcmp(dp->d_name, "..") != 0) {
 244                                 if (atoi(dp->d_name) > maxpts) {
 245                                         maxpts = atoi(dp->d_name);
 246                                         pts_valid = 1;
 247                                         curpts = 0;
 248                                 }
 249                         }
 250                 }
 251                 closedir(devpts_dir);
 252         }
 253         if (tf) {
 254                 rewind(tf);
 255                 return (1);
 256         } else if ( (tf = fopen(_PATH_TTYS, "r")) )
 257                 return (1);
 258         return (0);
 259 }
 260
 261 int
 262 endttyent()
 263 {
 264         int rval;
 265
 266         pts_valid = 0;
 267         /*
 268          * NB: Don't free `line' because getttynam()
 269          * may still be referencing it
 270          */
 271         if (tf) {
 272                 rval = (fclose(tf) != EOF);
 273                 tf = NULL;
 274                 return (rval);
 275         }
 276         return (1);
 277 }
 278
 279 static int
 280 isttystat(tty, flag)
 281         const char *tty;
 282         int flag;
 283 {
 284         struct ttyent *t;
 285
 286         return ((t = getttynam(tty)) == NULL) ? 0 : !!(t->ty_status & flag);
 287 }
 288
 289
 290 int
 291 isdialuptty(tty)
 292         const char *tty;
 293 {
 294
 295         return isttystat(tty, TTY_DIALUP);
 296 }
 297
 298 int isnettty(tty)
 299         const char *tty;
 300 {
 301
 302         return isttystat(tty, TTY_NETWORK);
 303 }