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  * $FreeBSD: src/lib/libc/gen/getttyent.c,v 1.13 2005/07/25 17:57:15 mdodd Exp $
  34  * $DragonFly: src/lib/libc/gen/getttyent.c,v 1.5 2005/11/13 00:07:42 swildner Exp $
  35  *
  36  * @(#)getttyent.c      8.1 (Berkeley) 6/4/93
  37  */
  38
  39 #include <sys/cdefs.h>
  40
  41 #include <ttyent.h>
  42 #include <stdio.h>
  43 #include <stdlib.h>
  44 #include <ctype.h>
  45 #include <string.h>
  46 #include <dirent.h>
  47 #include <paths.h>
  48
  49 static char zapchar;
  50 static FILE *tf;
  51 static int maxpts = -1;
  52 static int curpts = 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(const char *tty)
  64 {
  65         struct ttyent *t;
  66
  67         if (strncmp(tty, "/dev/", 5) == 0)
  68                 tty += 5;
  69         setttyent();
  70         while ( (t = getttyent()) )
  71                 if (!strcmp(tty, t->ty_name))
  72                         break;
  73         endttyent();
  74         return (t);
  75 }
  76
  77 struct ttyent *
  78 getttyent(void)
  79 {
  80         static struct ttyent tty;
  81         static char devpts_name[] = "pts/9999999999";
  82         char *p;
  83         int c;
  84         size_t i;
  85
  86         if (!tf && !setttyent())
  87                 return (NULL);
  88         for (;;) {
  89                 if (!fgets(p = line, lbsize, tf)) {
  90                         if (curpts <= maxpts) {
  91                                 sprintf(devpts_name, "pts/%d", curpts++);
  92                                 tty.ty_name = devpts_name;
  93                                 tty.ty_getty = NULL;
  94                                 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') && !feof(tf)) {
 105                         i = strlen(p);
 106                         lbsize += MALLOCCHUNK;
 107                         if ((p = realloc(line, lbsize)) == NULL) {
 108                                 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(char *p)
 187 {
 188         char *t;
 189         int c, q;
 190
 191         for (q = 0, t = p; (c = *p) != '\0'; p++) {
 192                 if (c == '"') {
 193                         q ^= QUOTED;    /* obscure, but nice */
 194                         continue;
 195                 }
 196                 if (q == QUOTED && *p == '\\' && *(p+1) == '"')
 197                         p++;
 198                 *t++ = *p;
 199                 if (q == QUOTED)
 200                         continue;
 201                 if (c == '#') {
 202                         zapchar = c;
 203                         *p = 0;
 204                         break;
 205                 }
 206                 if (c == '\t' || c == ' ' || c == '\n') {
 207                         zapchar = c;
 208                         *p++ = 0;
 209                         while ((c = *p) == '\t' || c == ' ' || c == '\n')
 210                                 p++;
 211                         break;
 212                 }
 213         }
 214         *--t = '\0';
 215         return (p);
 216 }
 217
 218 static char *
 219 value(char *p)
 220 {
 221
 222         return ((p = index(p, '=')) ? ++p : NULL);
 223 }
 224
 225 int
 226 setttyent(void)
 227 {
 228         DIR *devpts_dir;
 229         struct dirent *dp;
 230         int unit;
 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                 maxpts = -1;
 240                 while ((dp = readdir(devpts_dir))) {
 241                         if (strcmp(dp->d_name, ".") == 0 ||
 242                             strcmp(dp->d_name, "..") == 0)
 243                                 continue;
 244
 245                         unit = (int)strtol(dp->d_name, NULL, 10);
 246
 247                         if (unit > maxpts) {
 248                                 maxpts = unit;
 249                                 curpts = 0;
 250                         }
 251                 }
 252                 closedir(devpts_dir);
 253         }
 254         if (tf) {
 255                 rewind(tf);
 256                 return (1);
 257         } else if ( (tf = fopen(_PATH_TTYS, "r")) )
 258                 return (1);
 259         return (0);
 260 }
 261
 262 int
 263 endttyent(void)
 264 {
 265         int rval;
 266
 267         maxpts = -1;
 268         /*
 269          * NB: Don't free `line' because getttynam()
 270          * may still be referencing it
 271          */
 272         if (tf) {
 273                 rval = (fclose(tf) != EOF);
 274                 tf = NULL;
 275                 return (rval);
 276         }
 277         return (1);
 278 }
 279
 280 static int
 281 isttystat(const char *tty, int flag)
 282 {
 283         struct ttyent *t;
 284
 285         return ((t = getttynam(tty)) == NULL) ? 0 : !!(t->ty_status & flag);
 286 }
 287
 288
 289 int
 290 isdialuptty(const char *tty)
 291 {
 292
 293         return isttystat(tty, TTY_DIALUP);
 294 }
 295
 296 int
 297 isnettty(const char *tty)
 298 {
 299
 300         return isttystat(tty, TTY_NETWORK);
 301 }