xref: /freebsd/contrib/libpcap/etherent.c (revision 82431678fce5c893ef9c7418ad6d998ad4187de6)
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 #include <sys/types.h>
32 
33 #include <ctype.h>
34 #include <memory.h>
35 #include <stdio.h>
36 #include <string.h>
37 
38 #include "pcap-int.h"
39 
40 #include <pcap/namedb.h>
41 
42 #ifdef HAVE_OS_PROTO_H
43 #include "os-proto.h"
44 #endif
45 
46 static inline int xdtoi(int);
47 static inline int skip_space(FILE *);
48 static inline int skip_line(FILE *);
49 
50 /* Hex digit to integer. */
51 static inline int
52 xdtoi(c)
53 	register int c;
54 {
55 	if (isdigit(c))
56 		return c - '0';
57 	else if (islower(c))
58 		return c - 'a' + 10;
59 	else
60 		return c - 'A' + 10;
61 }
62 
63 static inline int
64 skip_space(f)
65 	FILE *f;
66 {
67 	int c;
68 
69 	do {
70 		c = getc(f);
71 	} while (isspace(c) && c != '\n');
72 
73 	return c;
74 }
75 
76 static inline int
77 skip_line(f)
78 	FILE *f;
79 {
80 	int c;
81 
82 	do
83 		c = getc(f);
84 	while (c != '\n' && c != EOF);
85 
86 	return c;
87 }
88 
89 struct pcap_etherent *
90 pcap_next_etherent(FILE *fp)
91 {
92 	register int c, d, i;
93 	char *bp;
94 	static struct pcap_etherent e;
95 
96 	memset((char *)&e, 0, sizeof(e));
97 	do {
98 		/* Find addr */
99 		c = skip_space(fp);
100 		if (c == '\n')
101 			continue;
102 
103 		/* If this is a comment, or first thing on line
104 		   cannot be etehrnet address, skip the line. */
105 		if (!isxdigit(c)) {
106 			c = skip_line(fp);
107 			continue;
108 		}
109 
110 		/* must be the start of an address */
111 		for (i = 0; i < 6; i += 1) {
112 			d = xdtoi(c);
113 			c = getc(fp);
114 			if (isxdigit(c)) {
115 				d <<= 4;
116 				d |= xdtoi(c);
117 				c = getc(fp);
118 			}
119 			e.addr[i] = d;
120 			if (c != ':')
121 				break;
122 			c = getc(fp);
123 		}
124 		if (c == EOF)
125 			break;
126 
127 		/* Must be whitespace */
128 		if (!isspace(c)) {
129 			c = skip_line(fp);
130 			continue;
131 		}
132 		c = skip_space(fp);
133 
134 		/* hit end of line... */
135 		if (c == '\n')
136 			continue;
137 
138 		if (c == '#') {
139 			c = skip_line(fp);
140 			continue;
141 		}
142 
143 		/* pick up name */
144 		bp = e.name;
145 		/* Use 'd' to prevent buffer overflow. */
146 		d = sizeof(e.name) - 1;
147 		do {
148 			*bp++ = c;
149 			c = getc(fp);
150 		} while (!isspace(c) && c != EOF && --d > 0);
151 		*bp = '\0';
152 
153 		/* Eat trailing junk */
154 		if (c != '\n')
155 			(void)skip_line(fp);
156 
157 		return &e;
158 
159 	} while (c != EOF);
160 
161 	return (NULL);
162 }
163