1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
|
/*
* (C)opyright 1993-1996 by Darren Reed.
*
* Redistribution and use in source and binary forms are permitted
* provided that this notice is preserved and due credit is given
* to the original author and the contributors.
*/
#include <stdio.h>
#include <string.h>
#if !defined(__SVR4) && !defined(__GNUC__)
#include <strings.h>
#endif
#include <sys/types.h>
#include <sys/time.h>
#include <stdlib.h>
#include <unistd.h>
#include <stddef.h>
#include <sys/socket.h>
#include <sys/ioctl.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip_var.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>
#include <netinet/tcpip.h>
#include <net/if.h>
#include "ipf.h"
#include "ipt.h"
#include "pcap.h"
#if !defined(lint) && defined(LIBC_SCCS)
static char rcsid[] = "$Id: ipft_pc.c,v 2.0.2.3 1997/03/10 08:10:26 darrenr Exp $";
#endif
struct llc {
int lc_sz; /* LLC header length */
int lc_to; /* LLC Type offset */
int lc_tl; /* LLC Type length */
};
/*
* While many of these maybe the same, some do have different header formats
* which make this useful.
*/
#define DLT_MAX 10
static struct llc llcs[DLT_MAX+1] = {
{ 0, 0, 0 }, /* DLT_NULL */
{ 14, 12, 2 }, /* DLT_E10MB */
{ 0, 0, 0 }, /* DLT_EN3MB */
{ 0, 0, 0 }, /* DLT_AX25 */
{ 0, 0, 0 }, /* DLT_PRONET */
{ 0, 0, 0 }, /* DLT_CHAOS */
{ 0, 0, 0 }, /* DLT_IEEE802 */
{ 0, 0, 0 }, /* DLT_ARCNET */
{ 0, 0, 0 }, /* DLT_SLIP */
{ 0, 0, 0 }, /* DLT_PPP */
{ 0, 0, 0 } /* DLT_FDDI */
};
static int pcap_open __P((char *));
static int pcap_close __P((void));
static int pcap_readip __P((char *, int, char **, int *));
static void swap_hdr __P((pcaphdr_t *));
static int pcap_read_rec __P((struct pcap_pkthdr *));
static int pfd = -1, s_type = -1, swapped = 0;
struct ipread pcap = { pcap_open, pcap_close, pcap_readip };
#define SWAPLONG(y) \
((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
#define SWAPSHORT(y) \
( (((y)&0xff)<<8) | (((y)&0xff00)>>8) )
static void swap_hdr(p)
pcaphdr_t *p;
{
p->pc_v_maj = SWAPSHORT(p->pc_v_maj);
p->pc_v_min = SWAPSHORT(p->pc_v_min);
p->pc_zone = SWAPLONG(p->pc_zone);
p->pc_sigfigs = SWAPLONG(p->pc_sigfigs);
p->pc_slen = SWAPLONG(p->pc_slen);
p->pc_type = SWAPLONG(p->pc_type);
}
static int pcap_open(fname)
char *fname;
{
pcaphdr_t ph;
int fd;
if (pfd != -1)
return pfd;
if (!strcmp(fname, "-"))
fd = 0;
else if ((fd = open(fname, O_RDONLY)) == -1)
return -1;
if (read(fd, (char *)&ph, sizeof(ph)) != sizeof(ph))
return -2;
if (ph.pc_id != TCPDUMP_MAGIC) {
if (SWAPLONG(ph.pc_id) != TCPDUMP_MAGIC) {
(void) close(fd);
return -2;
}
swapped = 1;
swap_hdr(&ph);
}
if (ph.pc_v_maj != PCAP_VERSION_MAJ || ph.pc_type > DLT_MAX) {
(void) close(fd);
return -2;
}
pfd = fd;
s_type = ph.pc_type;
printf("opened pcap file %s:\n", fname);
printf("\tid: %08x version: %d.%d type: %d snap %d\n",
ph.pc_id, ph.pc_v_maj, ph.pc_v_min, ph.pc_type, ph.pc_slen);
return fd;
}
static int pcap_close()
{
return close(pfd);
}
/*
* read in the header (and validate) which should be the first record
* in a pcap file.
*/
static int pcap_read_rec(rec)
struct pcap_pkthdr *rec;
{
int n, p;
if (read(pfd, (char *)rec, sizeof(*rec)) != sizeof(*rec))
return -2;
if (swapped) {
rec->ph_clen = SWAPLONG(rec->ph_clen);
rec->ph_len = SWAPLONG(rec->ph_len);
rec->ph_ts.tv_sec = SWAPLONG(rec->ph_ts.tv_sec);
rec->ph_ts.tv_usec = SWAPLONG(rec->ph_ts.tv_usec);
}
p = rec->ph_clen;
n = MIN(p, rec->ph_len);
if (!n || n < 0)
return -3;
return p;
}
#ifdef notyet
/*
* read an entire pcap packet record. only the data part is copied into
* the available buffer, with the number of bytes copied returned.
*/
static int pcap_read(buf, cnt)
char *buf;
int cnt;
{
struct pcap_pkthdr rec;
static char *bufp = NULL;
int i, n;
if ((i = pcap_read_rec(&rec)) <= 0)
return i;
if (!bufp)
bufp = malloc(i);
else
bufp = realloc(bufp, i);
if (read(pfd, bufp, i) != i)
return -2;
n = MIN(i, cnt);
bcopy(bufp, buf, n);
return n;
}
#endif
/*
* return only an IP packet read into buf
*/
static int pcap_readip(buf, cnt, ifn, dir)
char *buf, **ifn;
int cnt, *dir;
{
static char *bufp = NULL;
struct pcap_pkthdr rec;
struct llc *l;
char *s, ty[4];
int i, n;
do {
if ((i = pcap_read_rec(&rec)) <= 0)
return i;
if (!bufp)
bufp = malloc(i);
else
bufp = realloc(bufp, i);
s = bufp;
if (read(pfd, s, i) != i)
return -2;
l = &llcs[s_type];
i -= l->lc_sz;
s += l->lc_to;
bcopy(s, ty, l->lc_tl);
s += l->lc_tl;
} while (ty[0] != 0x8 && ty[1] != 0);
n = MIN(i, cnt);
bcopy(s, buf, n);
return n;
}
|