1/*	$OpenBSD: etherent.c,v 1.10 2024/04/05 18:01:56 deraadt Exp $	*/
2
3/*
4 * Copyright (c) 1990, 1993, 1994, 1995, 1996
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: (1) source code distributions
9 * retain the above copyright notice and this paragraph in its entirety, (2)
10 * distributions including binary code include the above copyright notice and
11 * this paragraph in its entirety in the documentation or other materials
12 * provided with the distribution, and (3) all advertising materials mentioning
13 * features or use of this software display the following acknowledgement:
14 * ``This product includes software developed by the University of California,
15 * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
16 * the University nor the names of its contributors may be used to endorse
17 * or promote products derived from this software without specific prior
18 * written permission.
19 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
20 * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
21 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
22 */
23
24#include <sys/types.h>
25
26#include <ctype.h>
27#include <stdio.h>
28#include <string.h>
29
30#include "pcap-int.h"
31
32#include <pcap-namedb.h>
33#ifdef HAVE_OS_PROTO_H
34#include "os-proto.h"
35#endif
36
37static __inline int xdtoi(int);
38static __inline int skip_space(FILE *);
39static __inline int skip_line(FILE *);
40
41/* Hex digit to integer. */
42static __inline int
43xdtoi(int c)
44{
45	if (isdigit(c))
46		return c - '0';
47	else if (islower(c))
48		return c - 'a' + 10;
49	else
50		return c - 'A' + 10;
51}
52
53static __inline int
54skip_space(FILE *f)
55{
56	int c;
57
58	do {
59		c = getc(f);
60	} while (isspace(c) && c != '\n');
61
62	return c;
63}
64
65static __inline int
66skip_line(FILE *f)
67{
68	int c;
69
70	do
71		c = getc(f);
72	while (c != '\n' && c != EOF);
73
74	return c;
75}
76
77struct pcap_etherent *
78pcap_next_etherent(FILE *fp)
79{
80	int c, d, i;
81	char *bp;
82	static struct pcap_etherent e;
83
84	memset((char *)&e, 0, sizeof(e));
85	do {
86		/* Find addr */
87		c = skip_space(fp);
88		if (c == '\n')
89			continue;
90
91		/* If this is a comment, or first thing on line
92		   cannot be etehrnet address, skip the line. */
93		if (!isxdigit(c)) {
94			c = skip_line(fp);
95			continue;
96		}
97
98		/* must be the start of an address */
99		for (i = 0; i < 6; i += 1) {
100			d = xdtoi(c);
101			c = getc(fp);
102			if (isxdigit(c)) {
103				d <<= 4;
104				d |= xdtoi(c);
105				c = getc(fp);
106			}
107			e.addr[i] = d;
108			if (c != ':')
109				break;
110			c = getc(fp);
111		}
112		if (c == EOF)
113			break;
114
115		/* Must be whitespace */
116		if (!isspace(c)) {
117			c = skip_line(fp);
118			continue;
119		}
120		c = skip_space(fp);
121
122		/* hit end of line... */
123		if (c == '\n')
124			continue;
125
126		if (c == '#') {
127			c = skip_line(fp);
128			continue;
129		}
130
131		/* pick up name */
132		bp = e.name;
133		/* Use 'd' to prevent buffer overflow. */
134		d = sizeof(e.name) - 1;
135		do {
136			*bp++ = c;
137			c = getc(fp);
138		} while (!isspace(c) && c != EOF && --d > 0);
139		*bp = '\0';
140
141		/* Eat trailing junk */
142		if (c != '\n')
143			(void)skip_line(fp);
144
145		return &e;
146
147	} while (c != EOF);
148
149	return (NULL);
150}
151