xref: /illumos-gate/usr/src/cmd/ipf/lib/common/ipft_pc.c (revision ab25eeb5)
1 /*
2  * Copyright (C) 1993-2001 by Darren Reed.
3  *
4  * See the IPFILTER.LICENCE file for details on licencing.
5  *
6  * $Id: ipft_pc.c,v 1.10 2004/02/07 18:17:40 darrenr Exp $
7  */
8 #include "ipf.h"
9 #include "pcap-ipf.h"
10 #include "bpf-ipf.h"
11 #include "ipt.h"
12 
13 #if !defined(lint)
14 static const char rcsid[] = "@(#)$Id: ipft_pc.c,v 1.10 2004/02/07 18:17:40 darrenr Exp $";
15 #endif
16 
17 struct	llc	{
18 	int	lc_type;
19 	int	lc_sz;	/* LLC header length */
20 	int	lc_to;	/* LLC Type offset */
21 	int	lc_tl;	/* LLC Type length */
22 };
23 
24 /*
25  * While many of these maybe the same, some do have different header formats
26  * which make this useful.
27  */
28 
29 static	struct	llc	llcs[] = {
30 	{ DLT_NULL, 0, 0, 0 },
31 	{ DLT_EN10MB, 14, 12, 2 },
32 	{ DLT_EN3MB, 0, 0, 0 },
33 	{ DLT_AX25, 0, 0, 0 },
34 	{ DLT_PRONET, 0, 0, 0 },
35 	{ DLT_CHAOS, 0, 0, 0 },
36 	{ DLT_IEEE802, 0, 0, 0 },
37 	{ DLT_ARCNET, 0, 0, 0 },
38 	{ DLT_SLIP, 0, 0, 0 },
39 	{ DLT_PPP, 0, 0, 0 },
40 	{ DLT_FDDI, 0, 0, 0 },
41 #ifdef DLT_ATMRFC1483
42 	{ DLT_ATMRFC1483, 0, 0, 0 },
43 #endif
44 	{ DLT_RAW, 0, 0, 0 },
45 #ifdef	DLT_ENC
46 	{ DLT_ENC, 0, 0, 0 },
47 #endif
48 #ifdef	DLT_SLIP_BSDOS
49 	{ DLT_SLIP_BSDOS, 0, 0, 0 },
50 #endif
51 #ifdef	DLT_PPP_BSDOS
52 	{ DLT_PPP_BSDOS, 0, 0, 0 },
53 #endif
54 #ifdef	DLT_HIPPI
55 	{ DLT_HIPPI, 0, 0, 0 },
56 #endif
57 #ifdef	DLT_HDLC
58 	{ DLT_HDLC, 0, 0, 0 },
59 #endif
60 #ifdef	DLT_PPP_SERIAL
61 	{ DLT_PPP_SERIAL, 4, 4, 0 },
62 #endif
63 #ifdef	DLT_PPP_ETHER
64 	{ DLT_PPP_ETHER, 8, 8, 0 },
65 #endif
66 #ifdef	DLT_ECONET
67 	{ DLT_ECONET, 0, 0, 0 },
68 #endif
69 	{ -1, -1, -1, -1 }
70 };
71 
72 static	int	pcap_open __P((char *));
73 static	int	pcap_close __P((void));
74 static	int	pcap_readip __P((char *, int, char **, int *));
75 static	void	swap_hdr __P((pcaphdr_t *));
76 static	int	pcap_read_rec __P((struct pcap_pkthdr *));
77 
78 static	int	pfd = -1, swapped = 0;
79 static	struct llc	*llcp = NULL;
80 
81 struct	ipread	pcap = { pcap_open, pcap_close, pcap_readip, 0 };
82 
83 #define	SWAPLONG(y)	\
84 	((((y)&0xff)<<24) | (((y)&0xff00)<<8) | (((y)&0xff0000)>>8) | (((y)>>24)&0xff))
85 #define	SWAPSHORT(y)	\
86 	( (((y)&0xff)<<8) | (((y)&0xff00)>>8) )
87 
swap_hdr(p)88 static	void	swap_hdr(p)
89 pcaphdr_t	*p;
90 {
91 	p->pc_v_maj = SWAPSHORT(p->pc_v_maj);
92 	p->pc_v_min = SWAPSHORT(p->pc_v_min);
93 	p->pc_zone = SWAPLONG(p->pc_zone);
94 	p->pc_sigfigs = SWAPLONG(p->pc_sigfigs);
95 	p->pc_slen = SWAPLONG(p->pc_slen);
96 	p->pc_type = SWAPLONG(p->pc_type);
97 }
98 
pcap_open(fname)99 static	int	pcap_open(fname)
100 char	*fname;
101 {
102 	pcaphdr_t ph;
103 	int fd, i;
104 
105 	if (pfd != -1)
106 		return pfd;
107 
108 	if (!strcmp(fname, "-"))
109 		fd = 0;
110 	else if ((fd = open(fname, O_RDONLY)) == -1)
111 		return -1;
112 
113 	if (read(fd, (char *)&ph, sizeof(ph)) != sizeof(ph))
114 		return -2;
115 
116 	if (ph.pc_id != TCPDUMP_MAGIC) {
117 		if (SWAPLONG(ph.pc_id) != TCPDUMP_MAGIC) {
118 			(void) close(fd);
119 			return -2;
120 		}
121 		swapped = 1;
122 		swap_hdr(&ph);
123 	}
124 
125 	if (ph.pc_v_maj != PCAP_VERSION_MAJ) {
126 		(void) close(fd);
127 		return -2;
128 	}
129 
130 	for (i = 0; llcs[i].lc_type != -1; i++)
131 		if (llcs[i].lc_type == ph.pc_type) {
132 			llcp = llcs + i;
133 			break;
134 		}
135 
136 	if (llcp == NULL) {
137 		(void) close(fd);
138 		return -2;
139 	}
140 
141 	pfd = fd;
142 	printf("opened pcap file %s:\n", fname);
143 	printf("\tid: %08x version: %d.%d type: %d snap %d\n",
144 		ph.pc_id, ph.pc_v_maj, ph.pc_v_min, ph.pc_type, ph.pc_slen);
145 
146 	return fd;
147 }
148 
149 
pcap_close()150 static	int	pcap_close()
151 {
152 	return close(pfd);
153 }
154 
155 
156 /*
157  * read in the header (and validate) which should be the first record
158  * in a pcap file.
159  */
pcap_read_rec(rec)160 static	int	pcap_read_rec(rec)
161 struct	pcap_pkthdr *rec;
162 {
163 	int	n, p;
164 
165 	if (read(pfd, (char *)rec, sizeof(*rec)) != sizeof(*rec))
166 		return -2;
167 
168 	if (swapped) {
169 		rec->ph_clen = SWAPLONG(rec->ph_clen);
170 		rec->ph_len = SWAPLONG(rec->ph_len);
171 		rec->ph_ts.tv_sec = SWAPLONG(rec->ph_ts.tv_sec);
172 		rec->ph_ts.tv_usec = SWAPLONG(rec->ph_ts.tv_usec);
173 	}
174 	p = rec->ph_clen;
175 	n = MIN(p, rec->ph_len);
176 	if (!n || n < 0)
177 		return -3;
178 
179 	return p;
180 }
181 
182 
183 #ifdef	notyet
184 /*
185  * read an entire pcap packet record.  only the data part is copied into
186  * the available buffer, with the number of bytes copied returned.
187  */
pcap_read(buf,cnt)188 static	int	pcap_read(buf, cnt)
189 char	*buf;
190 int	cnt;
191 {
192 	struct	pcap_pkthdr rec;
193 	static	char	*bufp = NULL;
194 	int	i, n;
195 
196 	if ((i = pcap_read_rec(&rec)) <= 0)
197 		return i;
198 
199 	if (!bufp)
200 		bufp = malloc(i);
201 	else
202 		bufp = realloc(bufp, i);
203 
204 	if (read(pfd, bufp, i) != i)
205 		return -2;
206 
207 	n = MIN(i, cnt);
208 	bcopy(bufp, buf, n);
209 	return n;
210 }
211 #endif
212 
213 
214 /*
215  * return only an IP packet read into buf
216  */
pcap_readip(buf,cnt,ifn,dir)217 static	int	pcap_readip(buf, cnt, ifn, dir)
218 char	*buf, **ifn;
219 int	cnt, *dir;
220 {
221 	static	char	*bufp = NULL;
222 	struct	pcap_pkthdr rec;
223 	struct	llc	*l;
224 	char	*s, ty[4];
225 	int	i, n;
226 
227 	l = llcp;
228 
229 	/* do { */
230 		if ((i = pcap_read_rec(&rec)) <= 0)
231 			return i;
232 
233 		if (!bufp)
234 			bufp = malloc(i);
235 		else
236 			bufp = realloc(bufp, i);
237 		s = bufp;
238 
239 		if (read(pfd, s, i) != i)
240 			return -2;
241 
242 		i -= l->lc_sz;
243 		s += l->lc_to;
244 		bcopy(s, ty, l->lc_tl);
245 		s += l->lc_tl;
246 	/* } while (ty[0] != 0x8 && ty[1] != 0); */
247 	n = MIN(i, cnt);
248 	bcopy(s, buf, n);
249 	return n;
250 }
251