The Tcpdump Group git mirrors - tcpdump/blob - missing/getservent.c

   1 /*
   2  * Copyright (c) 1983, 1993     The Regents of the University of California.
   3  * Copyright (c) 1993 Digital Equipment Corporation.
   4  * Copyright (c) 2012 G. Vanem <gvanem@yahoo.no>.
   5  * Copyright (c) 2017 Ali Abdulkadir <autostart.ini@gmail.com>.
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36
  37 #ifdef HAVE_CONFIG_H
  38 #include <config.h>
  39 #endif
  40
  41 #include <netdissect-stdinc.h>
  42 #include <getservent.h>
  43
  44 static FILE *servf = NULL;
  45 static char line[BUFSIZ+1];
  46 static struct servent serv;
  47 static char *serv_aliases[MAXALIASES];
  48 int _serv_stayopen;
  49 const char *etc_path(const char *file);
  50
  51 /*
  52 * Check if <file> exists in the current directory and, if so, return it.
  53 * Else return either "%SYSTEMROOT%\System32\drivers\etc\<file>"
  54 * or $PREFIX/etc/<file>.
  55 * "<file>" is aka __PATH_SERVICES (aka "services" on Windows and
  56 * "/etc/services" on other platforms that would need this).
  57 */
  58 const char *etc_path(const char *file)
  59 {
  60     const char *env = getenv(__PATH_SYSROOT);
  61     static char path[_MAX_PATH];
  62
  63     /* see if "<file>" exists locally or whether __PATH_SYSROOT is valid */
  64     if (fopen(file, "r") || !env)
  65         return (file);
  66     else
  67 #ifdef _WIN32
  68     snprintf(path, sizeof(path), "%s%s%s", env, __PATH_ETC_INET, file);
  69 #else
  70     snprintf(path, sizeof(path), "%s%s", env, file);
  71 #endif
  72     return (path);
  73 }
  74
  75 void
  76 setservent(int f)
  77 {
  78     if (servf == NULL)
  79         servf = fopen(etc_path(__PATH_SERVICES), "r");
  80     else
  81         rewind(servf);
  82     _serv_stayopen |= f;
  83 }
  84
  85 void
  86 endservent(void)
  87 {
  88     if (servf) {
  89         fclose(servf);
  90         servf = NULL;
  91     }
  92     _serv_stayopen = 0;
  93 }
  94
  95 struct servent *
  96 getservent(void)
  97 {
  98     char *p;
  99     char *cp, **q;
 100
 101     if (servf == NULL && (servf = fopen(etc_path(__PATH_SERVICES), "r")) == NULL)
 102         return (NULL);
 103
 104 again:
 105     if ((p = fgets(line, BUFSIZ, servf)) == NULL)
 106         return (NULL);
 107     if (*p == '#')
 108         goto again;
 109     cp = strpbrk(p, "#\n");
 110     if (cp == NULL)
 111         goto again;
 112     *cp = '\0';
 113     serv.s_name = p;
 114     p = strpbrk(p, " \t");
 115     if (p == NULL)
 116         goto again;
 117     *p++ = '\0';
 118     while (*p == ' ' || *p == '\t')
 119         p++;
 120     cp = strpbrk(p, ",/");
 121     if (cp == NULL)
 122         goto again;
 123     *cp++ = '\0';
 124     serv.s_port = htons((u_short)atoi(p));
 125     serv.s_proto = cp;
 126     q = serv.s_aliases = serv_aliases;
 127     cp = strpbrk(cp, " \t");
 128     if (cp != NULL)
 129         *cp++ = '\0';
 130     while (cp && *cp) {
 131         if (*cp == ' ' || *cp == '\t') {
 132             cp++;
 133             continue;
 134         }
 135         if (q < &serv_aliases[MAXALIASES - 1])
 136             *q++ = cp;
 137         cp = strpbrk(cp, " \t");
 138         if (cp != NULL)
 139             *cp++ = '\0';
 140     }
 141     *q = NULL;
 142     return (&serv);
 143 }