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 #ifndef lint
23 static const char rcsid[] _U_ =
24     "@(#) $Header: /tcpdump/master/libpcap/etherent.c,v 1.23 2006-10-04 18:09:22 guy Exp $ (LBL)";
25 #endif
26 
27 #ifdef HAVE_CONFIG_H
28 #include "config.h"
29 #endif
30 
31 #ifdef WIN32
32 #include <pcap-stdinc.h>
33 #else /* WIN32 */
34 #if HAVE_INTTYPES_H
35 #include <inttypes.h>
36 #elif HAVE_STDINT_H
37 #include <stdint.h>
38 #endif
39 #ifdef HAVE_SYS_BITYPES_H
40 #include <sys/bitypes.h>
41 #endif
42 #include <sys/types.h>
43 #endif /* WIN32 */
44 
45 #include <ctype.h>
46 #include <memory.h>
47 #include <stdio.h>
48 #include <string.h>
49 
50 #include "pcap-int.h"
51 
52 #include <pcap/namedb.h>
53 
54 #ifdef HAVE_OS_PROTO_H
55 #include "os-proto.h"
56 #endif
57 
58 static inline int xdtoi(int);
59 static inline int skip_space(FILE *);
60 static inline int skip_line(FILE *);
61 
62 /* Hex digit to integer. */
63 static inline int
xdtoi(c)64 xdtoi(c)
65 	register int c;
66 {
67 	if (isdigit(c))
68 		return c - '0';
69 	else if (islower(c))
70 		return c - 'a' + 10;
71 	else
72 		return c - 'A' + 10;
73 }
74 
75 static inline int
skip_space(f)76 skip_space(f)
77 	FILE *f;
78 {
79 	int c;
80 
81 	do {
82 		c = getc(f);
83 	} while (isspace(c) && c != '\n');
84 
85 	return c;
86 }
87 
88 static inline int
skip_line(f)89 skip_line(f)
90 	FILE *f;
91 {
92 	int c;
93 
94 	do
95 		c = getc(f);
96 	while (c != '\n' && c != EOF);
97 
98 	return c;
99 }
100 
101 struct pcap_etherent *
pcap_next_etherent(FILE * fp)102 pcap_next_etherent(FILE *fp)
103 {
104 	register int c, d, i;
105 	char *bp;
106 	static struct pcap_etherent e;
107 
108 	memset((char *)&e, 0, sizeof(e));
109 	do {
110 		/* Find addr */
111 		c = skip_space(fp);
112 		if (c == '\n')
113 			continue;
114 
115 		/* If this is a comment, or first thing on line
116 		   cannot be etehrnet address, skip the line. */
117 		if (!isxdigit(c)) {
118 			c = skip_line(fp);
119 			continue;
120 		}
121 
122 		/* must be the start of an address */
123 		for (i = 0; i < 6; i += 1) {
124 			d = xdtoi(c);
125 			c = getc(fp);
126 			if (isxdigit(c)) {
127 				d <<= 4;
128 				d |= xdtoi(c);
129 				c = getc(fp);
130 			}
131 			e.addr[i] = d;
132 			if (c != ':')
133 				break;
134 			c = getc(fp);
135 		}
136 		if (c == EOF)
137 			break;
138 
139 		/* Must be whitespace */
140 		if (!isspace(c)) {
141 			c = skip_line(fp);
142 			continue;
143 		}
144 		c = skip_space(fp);
145 
146 		/* hit end of line... */
147 		if (c == '\n')
148 			continue;
149 
150 		if (c == '#') {
151 			c = skip_line(fp);
152 			continue;
153 		}
154 
155 		/* pick up name */
156 		bp = e.name;
157 		/* Use 'd' to prevent buffer overflow. */
158 		d = sizeof(e.name) - 1;
159 		do {
160 			*bp++ = c;
161 			c = getc(fp);
162 		} while (!isspace(c) && c != EOF && --d > 0);
163 		*bp = '\0';
164 
165 		/* Eat trailing junk */
166 		if (c != '\n')
167 			(void)skip_line(fp);
168 
169 		return &e;
170 
171 	} while (c != EOF);
172 
173 	return (NULL);
174 }
175