The Tcpdump Group git mirrors - libpcap/blob - etherent.c

   1 /*
   2  * Copyright (c) 1990, 1993, 1994, 1995, 1996
   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: (1) source code distributions
   7  * retain the above copyright notice and this paragraph in its entirety, (2)
   8  * distributions including binary code include the above copyright notice and
   9  * this paragraph in its entirety in the documentation or other materials
  10  * provided with the distribution, and (3) all advertising materials mentioning
  11  * features or use of this software display the following acknowledgement:
  12  * ``This product includes software developed by the University of California,
  13  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  14  * the University nor the names of its contributors may be used to endorse
  15  * or promote products derived from this software without specific prior
  16  * written permission.
  17  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  18  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  19  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  20  */
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <pcap-types.h>
  27
  28 #include <ctype.h>
  29 #include <memory.h>
  30 #include <stdio.h>
  31 #include <string.h>
  32
  33 #include "pcap-int.h"
  34
  35 #include <pcap/namedb.h>
  36
  37 #ifdef HAVE_OS_PROTO_H
  38 #include "os-proto.h"
  39 #endif
  40
  41 static inline int xdtoi(int);
  42 static inline int skip_space(FILE *);
  43 static inline int skip_line(FILE *);
  44
  45 /* Hex digit to integer. */
  46 static inline int
  47 xdtoi(c)
  48         register int c;
  49 {
  50         if (isdigit(c))
  51                 return c - '0';
  52         else if (islower(c))
  53                 return c - 'a' + 10;
  54         else
  55                 return c - 'A' + 10;
  56 }
  57
  58 static inline int
  59 skip_space(f)
  60         FILE *f;
  61 {
  62         int c;
  63
  64         do {
  65                 c = getc(f);
  66         } while (isspace(c) && c != '\n');
  67
  68         return c;
  69 }
  70
  71 static inline int
  72 skip_line(f)
  73         FILE *f;
  74 {
  75         int c;
  76
  77         do
  78                 c = getc(f);
  79         while (c != '\n' && c != EOF);
  80
  81         return c;
  82 }
  83
  84 struct pcap_etherent *
  85 pcap_next_etherent(FILE *fp)
  86 {
  87         register int c, d, i;
  88         char *bp;
  89         static struct pcap_etherent e;
  90
  91         memset((char *)&e, 0, sizeof(e));
  92         for (;;) {
  93                 /* Find addr */
  94                 c = skip_space(fp);
  95                 if (c == EOF)
  96                         return (NULL);
  97                 if (c == '\n')
  98                         continue;
  99
 100                 /* If this is a comment, or first thing on line
 101                    cannot be Ethernet address, skip the line. */
 102                 if (!isxdigit(c)) {
 103                         c = skip_line(fp);
 104                         if (c == EOF)
 105                                 return (NULL);
 106                         continue;
 107                 }
 108
 109                 /* must be the start of an address */
 110                 for (i = 0; i < 6; i += 1) {
 111                         d = xdtoi(c);
 112                         c = getc(fp);
 113                         if (c == EOF)
 114                                 return (NULL);
 115                         if (isxdigit(c)) {
 116                                 d <<= 4;
 117                                 d |= xdtoi(c);
 118                                 c = getc(fp);
 119                                 if (c == EOF)
 120                                         return (NULL);
 121                         }
 122                         e.addr[i] = d;
 123                         if (c != ':')
 124                                 break;
 125                         c = getc(fp);
 126                         if (c == EOF)
 127                                 return (NULL);
 128                 }
 129
 130                 /* Must be whitespace */
 131                 if (!isspace(c)) {
 132                         c = skip_line(fp);
 133                         if (c == EOF)
 134                                 return (NULL);
 135                         continue;
 136                 }
 137                 c = skip_space(fp);
 138                 if (c == EOF)
 139                         return (NULL);
 140
 141                 /* hit end of line... */
 142                 if (c == '\n')
 143                         continue;
 144
 145                 if (c == '#') {
 146                         c = skip_line(fp);
 147                         if (c == EOF)
 148                                 return (NULL);
 149                         continue;
 150                 }
 151
 152                 /* pick up name */
 153                 bp = e.name;
 154                 /* Use 'd' to prevent buffer overflow. */
 155                 d = sizeof(e.name) - 1;
 156                 do {
 157                         *bp++ = c;
 158                         c = getc(fp);
 159                         if (c == EOF)
 160                                 return (NULL);
 161                 } while (!isspace(c) && --d > 0);
 162                 *bp = '\0';
 163
 164                 /* Eat trailing junk */
 165                 if (c != '\n')
 166                         (void)skip_line(fp);
 167
 168                 return &e;
 169         }
 170 }