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 #include <config.h>
23
24 #include <pcap-types.h>
25
26 #include <memory.h>
27 #include <stdio.h>
28 #include <string.h>
29
30 #include "pcap-int.h"
31
32 #include <pcap/namedb.h>
33
34 #include "thread-local.h"
35
36 #ifdef HAVE_OS_PROTO_H
37 #include "os-proto.h"
38 #endif
39
40 static inline int skip_space(FILE *);
41 static inline int skip_line(FILE *);
42
43 /* Hex digit to integer. */
44 static inline u_char
xdtoi(u_char c)45 xdtoi(u_char c)
46 {
47 if (c >= '0' && c <= '9')
48 return (u_char)(c - '0');
49 else if (c >= 'a' && c <= 'f')
50 return (u_char)(c - 'a' + 10);
51 else
52 return (u_char)(c - 'A' + 10);
53 }
54
55 /*
56 * Skip linear white space (space and tab) and any CRs before LF.
57 * Stop when we hit a non-white-space character or an end-of-line LF.
58 */
59 static inline int
skip_space(FILE * f)60 skip_space(FILE *f)
61 {
62 int c;
63
64 do {
65 c = getc(f);
66 } while (c == ' ' || c == '\t' || c == '\r');
67
68 return c;
69 }
70
71 static inline int
skip_line(FILE * f)72 skip_line(FILE *f)
73 {
74 int c;
75
76 do
77 c = getc(f);
78 while (c != '\n' && c != EOF);
79
80 return c;
81 }
82
83 struct pcap_etherent *
pcap_next_etherent(FILE * fp)84 pcap_next_etherent(FILE *fp)
85 {
86 register int c, i;
87 u_char d;
88 char *bp;
89 size_t namesize;
90 static thread_local struct pcap_etherent e;
91
92 memset((char *)&e, 0, sizeof(e));
93 for (;;) {
94 /* Find addr */
95 c = skip_space(fp);
96 if (c == EOF)
97 return (NULL);
98 if (c == '\n')
99 continue;
100
101 /* If this is a comment, or first thing on line
102 cannot be Ethernet address, skip the line. */
103 if (!PCAP_ISXDIGIT(c)) {
104 c = skip_line(fp);
105 if (c == EOF)
106 return (NULL);
107 continue;
108 }
109
110 /* must be the start of an address */
111 for (i = 0; i < 6; i += 1) {
112 d = xdtoi((u_char)c);
113 c = getc(fp);
114 if (c == EOF)
115 return (NULL);
116 if (PCAP_ISXDIGIT(c)) {
117 d <<= 4;
118 d |= xdtoi((u_char)c);
119 c = getc(fp);
120 if (c == EOF)
121 return (NULL);
122 }
123 e.addr[i] = d;
124 if (c != ':')
125 break;
126 c = getc(fp);
127 if (c == EOF)
128 return (NULL);
129 }
130
131 /* Must be whitespace */
132 if (c != ' ' && c != '\t' && c != '\r' && c != '\n') {
133 c = skip_line(fp);
134 if (c == EOF)
135 return (NULL);
136 continue;
137 }
138 c = skip_space(fp);
139 if (c == EOF)
140 return (NULL);
141
142 /* hit end of line... */
143 if (c == '\n')
144 continue;
145
146 if (c == '#') {
147 c = skip_line(fp);
148 if (c == EOF)
149 return (NULL);
150 continue;
151 }
152
153 /* pick up name */
154 bp = e.name;
155 /* Use 'namesize' to prevent buffer overflow. */
156 namesize = sizeof(e.name) - 1;
157 do {
158 *bp++ = (u_char)c;
159 c = getc(fp);
160 if (c == EOF)
161 return (NULL);
162 } while (c != ' ' && c != '\t' && c != '\r' && c != '\n'
163 && --namesize != 0);
164 *bp = '\0';
165
166 /* Eat trailing junk */
167 if (c != '\n')
168 (void)skip_line(fp);
169
170 return &e;
171 }
172 }
173