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 1.11 1999/11/04 04:16:27 ache 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 <ttyent.h>
  40 #include <stdio.h>
  41 #include <stdlib.h>
  42 #include <ctype.h>
  43 #include <string.h>
  44
  45 static char zapchar;
  46 static FILE *tf;
  47 static size_t lbsize;
  48 static char *line;
  49
  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         char *p;
  75         int c;
  76         size_t i;
  77
  78         if (!tf && !setttyent())
  79                 return (NULL);
  80         for (;;) {
  81                 if (!fgets(p = line, lbsize, tf))
  82                         return (NULL);
  83                 /* extend buffer if line was too big, and retry */
  84                 while (!index(p, '\n')) {
  85                         i = strlen(p);
  86                         lbsize += MALLOCCHUNK;
  87                         if ((p = realloc(line, lbsize)) == NULL) {
  88                                 endttyent();
  89                                 return (NULL);
  90                         }
  91                         line = p;
  92                         if (!fgets(&line[i], lbsize - i, tf))
  93                                 return (NULL);
  94                 }
  95                 while (isspace((unsigned char)*p))
  96                         ++p;
  97                 if (*p && *p != '#')
  98                         break;
  99         }
 100
 101 #define scmp(e) !strncmp(p, e, sizeof(e) - 1) && isspace((unsigned char)p[sizeof(e) - 1])
 102 #define vcmp(e) !strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
 103
 104         zapchar = 0;
 105         tty.ty_name = p;
 106         p = skip(p);
 107         if (!*(tty.ty_getty = p))
 108                 tty.ty_getty = tty.ty_type = NULL;
 109         else {
 110                 p = skip(p);
 111                 if (!*(tty.ty_type = p))
 112                         tty.ty_type = NULL;
 113                 else {
 114                         /* compatibility kludge: handle network/dialup specially */
 115                         if (scmp(_TTYS_DIALUP))
 116                                 tty.ty_status |= TTY_DIALUP;
 117                         else if (scmp(_TTYS_NETWORK))
 118                                 tty.ty_status |= TTY_NETWORK;
 119                         p = skip(p);
 120                 }
 121         }
 122         tty.ty_status = 0;
 123         tty.ty_window = NULL;
 124         tty.ty_group  = _TTYS_NOGROUP;
 125
 126         for (; *p; p = skip(p)) {
 127                 if (scmp(_TTYS_OFF))
 128                         tty.ty_status &= ~TTY_ON;
 129                 else if (scmp(_TTYS_ON))
 130                         tty.ty_status |= TTY_ON;
 131                 else if (scmp(_TTYS_SECURE))
 132                         tty.ty_status |= TTY_SECURE;
 133                 else if (scmp(_TTYS_INSECURE))
 134                         tty.ty_status &= ~TTY_SECURE;
 135                 else if (scmp(_TTYS_DIALUP))
 136                         tty.ty_status |= TTY_DIALUP;
 137                 else if (scmp(_TTYS_NETWORK))
 138                         tty.ty_status |= TTY_NETWORK;
 139                 else if (vcmp(_TTYS_WINDOW))
 140                         tty.ty_window = value(p);
 141                 else if (vcmp(_TTYS_GROUP))
 142                         tty.ty_group = value(p);
 143                 else
 144                         break;
 145         }
 146
 147         if (zapchar == '#' || *p == '#')
 148                 while ((c = *++p) == ' ' || c == '\t')
 149                         ;
 150         tty.ty_comment = p;
 151         if (*p == 0)
 152                 tty.ty_comment = 0;
 153         if ( (p = index(p, '\n')) )
 154                 *p = '\0';
 155         return (&tty);
 156 }
 157
 158 #define QUOTED  1
 159
 160 /*
 161  * Skip over the current field, removing quotes, and return a pointer to
 162  * the next field.
 163  */
 164 static char *
 165 skip(char *p)
 166 {
 167         char *t;
 168         int c, q;
 169
 170         for (q = 0, t = p; (c = *p) != '\0'; p++) {
 171                 if (c == '"') {
 172                         q ^= QUOTED;    /* obscure, but nice */
 173                         continue;
 174                 }
 175                 if (q == QUOTED && *p == '\\' && *(p+1) == '"')
 176                         p++;
 177                 *t++ = *p;
 178                 if (q == QUOTED)
 179                         continue;
 180                 if (c == '#') {
 181                         zapchar = c;
 182                         *p = 0;
 183                         break;
 184                 }
 185                 if (c == '\t' || c == ' ' || c == '\n') {
 186                         zapchar = c;
 187                         *p++ = 0;
 188                         while ((c = *p) == '\t' || c == ' ' || c == '\n')
 189                                 p++;
 190                         break;
 191                 }
 192         }
 193         *--t = '\0';
 194         return (p);
 195 }
 196
 197 static char *
 198 value(char *p)
 199 {
 200
 201         return ((p = index(p, '=')) ? ++p : NULL);
 202 }
 203
 204 int
 205 setttyent(void)
 206 {
 207
 208         if (line == NULL) {
 209                 if ((line = malloc(MALLOCCHUNK)) == NULL)
 210                         return (0);
 211                 lbsize = MALLOCCHUNK;
 212         }
 213         if (tf) {
 214                 rewind(tf);
 215                 return (1);
 216         } else if ( (tf = fopen(_PATH_TTYS, "r")) )
 217                 return (1);
 218         return (0);
 219 }
 220
 221 int
 222 endttyent(void)
 223 {
 224         int rval;
 225
 226         /*
 227          * NB: Don't free `line' because getttynam()
 228          * may still be referencing it
 229          */
 230         if (tf) {
 231                 rval = (fclose(tf) != EOF);
 232                 tf = NULL;
 233                 return (rval);
 234         }
 235         return (1);
 236 }
 237
 238 static int
 239 isttystat(const char *tty, int flag)
 240 {
 241         struct ttyent *t;
 242
 243         return ((t = getttynam(tty)) == NULL) ? 0 : !!(t->ty_status & flag);
 244 }
 245
 246
 247 int
 248 isdialuptty(const char *tty)
 249 {
 250
 251         return isttystat(tty, TTY_DIALUP);
 252 }
 253
 254 int
 255 isnettty(const char *tty)
 256 {
 257
 258         return isttystat(tty, TTY_NETWORK);
 259 }