lib/libc/gen/getttyent.c

   1 /*      $NetBSD: getttyent.c,v 1.26 2013/06/30 10:07:43 martin Exp $    */
   2
   3 /*
   4  * Copyright (c) 1989, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 #if 0
  35 static char sccsid[] = "@(#)getttyent.c 8.1 (Berkeley) 6/4/93";
  36 #else
  37 __RCSID("$NetBSD: getttyent.c,v 1.26 2013/06/30 10:07:43 martin Exp $");
  38 #endif
  39 #endif /* LIBC_SCCS and not lint */
  40
  41 #include "namespace.h"
  42
  43 #include <assert.h>
  44 #include <ctype.h>
  45 #include <stdio.h>
  46 #include <string.h>
  47 #include <ttyent.h>
  48 #include <errno.h>
  49 #include <err.h>
  50 #include <stdlib.h>
  51
  52 #include <sys/sysctl.h>
  53 #include <sys/utsname.h>
  54
  55 #ifdef __weak_alias
  56 __weak_alias(endttyent,_endttyent)
  57 __weak_alias(getttyent,_getttyent)
  58 __weak_alias(getttynam,_getttynam)
  59 __weak_alias(setttyent,_setttyent)
  60 __weak_alias(setttyentpath,_setttyentpath)
  61 #endif
  62
  63 static FILE *tf;
  64 static size_t lineno = 0;
  65 static char *skip(char *, char *);
  66 static char *value(char *);
  67
  68 struct ttyent *
  69 getttynam(const char *tty)
  70 {
  71         struct ttyent *t;
  72
  73         _DIAGASSERT(tty != NULL);
  74
  75         setttyent();
  76         while ((t = getttyent()) != NULL)
  77                 if (!strcmp(tty, t->ty_name))
  78                         break;
  79         endttyent();
  80         return (t);
  81 }
  82
  83 struct ttyent *
  84 getttyent(void)
  85 {
  86         static struct ttyent tty;
  87         int c;
  88         char *p;
  89         size_t len;
  90         static char *line = NULL;
  91         char zapchar;
  92
  93         if (line)
  94                 free(line);
  95
  96         if (!tf && !setttyent())
  97                 return NULL;
  98
  99         for (;;) {
 100                 errno = 0;
 101                 line = fparseln(tf, &len, &lineno, NULL, FPARSELN_UNESCALL);
 102                 if (line == NULL) {
 103                         if (errno != 0)
 104                                 warn(__func__);
 105                         return NULL;
 106                 }
 107                 for (p = line; *p && isspace((unsigned char)*p); p++)
 108                         continue;
 109                 if (*p && *p != '#')
 110                         break;
 111                 free(line);
 112         }
 113
 114         tty.ty_name = p;
 115         p = skip(p, &zapchar);
 116         if (*(tty.ty_getty = p) == '\0')
 117                 tty.ty_getty = tty.ty_type = NULL;
 118         else {
 119                 p = skip(p, &zapchar);
 120                 if (*(tty.ty_type = p) == '\0')
 121                         tty.ty_type = NULL;
 122                 else
 123                         p = skip(p, &zapchar);
 124         }
 125         tty.ty_status = 0;
 126         tty.ty_window = NULL;
 127         tty.ty_class = NULL;
 128
 129 #define scmp(e) !strncmp(p, e, sizeof(e) - 1) && (isspace((unsigned char) p[sizeof(e) - 1]) || p[sizeof(e) - 1] == '\0')
 130 #define vcmp(e) !strncmp(p, e, sizeof(e) - 1) && p[sizeof(e) - 1] == '='
 131         for (; *p; p = skip(p, &zapchar)) {
 132                 if (scmp(_TTYS_OFF))
 133                         tty.ty_status &= ~TTY_ON;
 134                 else if (scmp(_TTYS_ON))
 135                         tty.ty_status |= TTY_ON;
 136                 else if (scmp(_TTYS_SECURE))
 137                         tty.ty_status |= TTY_SECURE;
 138                 else if (scmp(_TTYS_LOCAL))
 139                         tty.ty_status |= TTY_LOCAL;
 140                 else if (scmp(_TTYS_RTSCTS))
 141                         tty.ty_status |= TTY_RTSCTS;
 142                 else if (scmp(_TTYS_DTRCTS))
 143                         tty.ty_status |= TTY_DTRCTS;
 144                 else if (scmp(_TTYS_SOFTCAR))
 145                         tty.ty_status |= TTY_SOFTCAR;
 146                 else if (scmp(_TTYS_MDMBUF))
 147                         tty.ty_status |= TTY_MDMBUF;
 148                 else if (vcmp(_TTYS_WINDOW))
 149                         tty.ty_window = value(p);
 150                 else if (vcmp(_TTYS_CLASS))
 151                         tty.ty_class = value(p);
 152                 else
 153                         warnx("%s: %s, %lu: unknown option `%s'",
 154                             __func__, _PATH_TTYS, (unsigned long)lineno, p);
 155         }
 156
 157         if (zapchar == '#' || *p == '#')
 158                 while ((c = *++p) == ' ' || c == '\t')
 159                         continue;
 160         tty.ty_comment = p;
 161         if (*p == '\0')
 162                 tty.ty_comment = NULL;
 163         if ((p = strchr(p, '\n')) != NULL)
 164                 *p = '\0';
 165         return &tty;
 166 }
 167
 168 #define QUOTED  1
 169
 170 /*
 171  * Skip over the current field, removing quotes, and return a pointer to
 172  * the next field.
 173  */
 174 static char *
 175 skip(char *p, char *zapchar)
 176 {
 177         char *t;
 178         int c, q;
 179
 180         _DIAGASSERT(p != NULL);
 181         *zapchar = '\0';
 182
 183         for (q = 0, t = p; (c = *p) != '\0'; p++) {
 184                 if (c == '"') {
 185                         q ^= QUOTED;    /* obscure, but nice */
 186                         continue;
 187                 }
 188                 if (q == QUOTED && *p == '\\' && *(p+1) == '"')
 189                         p++;
 190                 *t++ = *p;
 191                 if (q == QUOTED)
 192                         continue;
 193                 if (c == '#') {
 194                         *zapchar = c;
 195                         *p = '\0';
 196                         *--t = '\0';
 197                         return p;
 198                 }
 199                 if (c == '\t' || c == ' ' || c == '\n') {
 200                         *zapchar = c;
 201                         *p++ = '\0';
 202                         while ((c = *p) == '\t' || c == ' ' || c == '\n')
 203                                 p++;
 204                         *--t = '\0';
 205                         return p;
 206                 }
 207         }
 208         if (t != p)
 209                 *t = '\0';
 210         return p;
 211 }
 212
 213 static char *
 214 value(char *p)
 215 {
 216
 217         _DIAGASSERT(p != NULL);
 218
 219         return (p = strchr(p, '=')) != NULL ? ++p : NULL;
 220 }
 221
 222 int
 223 setttyentpath(const char *path)
 224 {
 225         lineno = 0;
 226         if (tf) {
 227                 rewind(tf);
 228                 return 1;
 229         }
 230
 231         /*
 232          * Try <path>.$MACHINE (e.g. etc/ttys.amd64)
 233          */
 234         {
 235                 char machine[_SYS_NMLN];
 236                 const int mib[] = { [0] = CTL_HW, [1] = HW_MACHINE, };
 237                 size_t len = sizeof(machine);
 238
 239                 if (sysctl(mib, (u_int)__arraycount(mib), machine, &len,
 240                      NULL, 0) != -1) {
 241                         char npath[PATH_MAX];
 242                         (void)snprintf(npath, sizeof(npath), "%s.%s", path,
 243                             machine);
 244                         if ((tf = fopen(npath, "re")) != NULL)
 245                                 return 1;
 246                 }
 247         }
 248
 249         if ((tf = fopen(path, "re")) != NULL)
 250                 return 1;
 251         return 0;
 252 }
 253
 254 int
 255 setttyent(void)
 256 {
 257         return setttyentpath(_PATH_TTYS);
 258 }
 259
 260 int
 261 endttyent(void)
 262 {
 263         int rval;
 264
 265         if (tf) {
 266                 rval = !(fclose(tf) == EOF);
 267                 tf = NULL;
 268                 return rval;
 269         }
 270         return 1;
 271 }