1/*	$FreeBSD: stable/11/contrib/ipfilter/lib/ipft_tx.c 369245 2021-02-09 13:47:46Z git2svn $	*/
2
3/*
4 * Copyright (C) 2012 by Darren Reed.
5 *
6 * See the IPFILTER.LICENCE file for details on licencing.
7 *
8 * $Id$
9 */
10#if !defined(lint)
11static const char sccsid[] = "@(#)ipft_tx.c	1.7 6/5/96 (C) 1993 Darren Reed";
12static const char rcsid[] = "@(#)$Id$";
13#endif
14
15#include <ctype.h>
16
17#include "ipf.h"
18#include "ipt.h"
19
20extern	int	opts;
21
22static	char	*tx_proto = "";
23
24static	int	text_open(char *), text_close(void);
25static	int	text_readip(mb_t *, char **, int *);
26static	int	parseline(char *, ip_t *, char **, int *);
27
28static	char	myflagset[] = "FSRPAUEC";
29static	u_char	myflags[] = { TH_FIN, TH_SYN, TH_RST, TH_PUSH,
30				TH_ACK, TH_URG, TH_ECN, TH_CWR };
31
32struct	ipread	iptext = { text_open, text_close, text_readip, R_DO_CKSUM };
33static	FILE	*tfp = NULL;
34static	int	tfd = -1;
35
36static	u_32_t	tx_hostnum(char *, int *);
37static	u_short	tx_portnum(char *);
38
39#ifdef USE_INET6
40int parseipv6(char **, ip6_t *, char **, int *);
41#endif
42
43/*
44 * returns an ip address as a long var as a result of either a DNS lookup or
45 * straight inet_addr() call
46 */
47static	u_32_t	tx_hostnum(host, resolved)
48	char	*host;
49	int	*resolved;
50{
51	i6addr_t	ipa;
52
53	*resolved = 0;
54	if (!strcasecmp("any", host))
55		return 0L;
56	if (ISDIGIT(*host))
57		return inet_addr(host);
58
59	if (gethost(AF_INET, host, &ipa) == -1) {
60		*resolved = -1;
61		fprintf(stderr, "can't resolve hostname: %s\n", host);
62		return 0;
63	}
64	return ipa.in4.s_addr;
65}
66
67
68/*
69 * find the port number given by the name, either from getservbyname() or
70 * straight atoi()
71 */
72static	u_short	tx_portnum(name)
73	char	*name;
74{
75	struct	servent	*sp;
76
77	if (ISDIGIT(*name))
78		return (u_short)atoi(name);
79	sp = getservbyname(name, tx_proto);
80	if (sp)
81		return ntohs(sp->s_port);
82	(void) fprintf(stderr, "unknown service \"%s\".\n", name);
83	return 0;
84}
85
86
87static	int	text_open(fname)
88	char	*fname;
89{
90	if (tfp && tfd != -1) {
91		rewind(tfp);
92		return tfd;
93	}
94
95	if (!strcmp(fname, "-")) {
96		tfd = 0;
97		tfp = stdin;
98	} else {
99		tfd = open(fname, O_RDONLY);
100		if (tfd != -1)
101			tfp = fdopen(tfd, "r");
102	}
103	return tfd;
104}
105
106
107static	int	text_close()
108{
109	int	cfd = tfd;
110
111	tfd = -1;
112	return close(cfd);
113}
114
115
116static	int	text_readip(mb, ifn, dir)
117	mb_t	*mb;
118	char	**ifn;
119	int	*dir;
120{
121	register char *s;
122	char	line[513];
123	ip_t	*ip;
124	char	*buf;
125	int	cnt;
126
127	buf = (char *)mb->mb_buf;
128	cnt = sizeof(mb->mb_buf);
129
130	*ifn = NULL;
131	while (fgets(line, sizeof(line)-1, tfp)) {
132		if ((s = strchr(line, '\n')))
133			*s = '\0';
134		if ((s = strchr(line, '\r')))
135			*s = '\0';
136		if ((s = strchr(line, '#')))
137			*s = '\0';
138		if (!*line)
139			continue;
140		if ((opts & OPT_DEBUG) != 0)
141			printf("input: %s\n", line);
142		*ifn = NULL;
143		*dir = 0;
144		if (!parseline(line, (ip_t *)buf, ifn, dir)) {
145			ip = (ip_t *)buf;
146			if (IP_V(ip) == 6) {
147#ifdef USE_INET6
148				mb->mb_len = ntohs(((ip6_t *)ip)->ip6_plen) +
149				       sizeof(ip6_t);
150#else
151				mb->mb_len = 0;
152#endif
153			} else {
154				mb->mb_len = ntohs(ip->ip_len);
155			}
156			return mb->mb_len;
157		}
158	}
159	if (feof(tfp))
160		return 0;
161	return -1;
162}
163
164static	int	parseline(line, ip, ifn, out)
165	char	*line;
166	ip_t	*ip;
167	char	**ifn;
168	int	*out;
169{
170	tcphdr_t	th, *tcp = &th;
171	struct	icmp	icmp, *ic = &icmp;
172	char	*cps[20], **cpp, c, ipopts[68];
173	int	i, r;
174
175	if (*ifn)
176		free(*ifn);
177	bzero((char *)ip, MAX(sizeof(*tcp), sizeof(*ic)) + sizeof(*ip));
178	bzero((char *)tcp, sizeof(*tcp));
179	bzero((char *)ic, sizeof(*ic));
180	bzero(ipopts, sizeof(ipopts));
181	IP_HL_A(ip, sizeof(*ip) >> 2);
182	IP_V_A(ip, IPVERSION);
183	ip->ip_ttl = 63;
184	for (i = 0, cps[0] = strtok(line, " \b\t\r\n"); cps[i] && i < 19; )
185		cps[++i] = strtok(NULL, " \b\t\r\n");
186
187	cpp = cps;
188	if (!*cpp)
189		return 1;
190
191	c = **cpp;
192	if (!ISALPHA(c) || (TOLOWER(c) != 'o' && TOLOWER(c) != 'i')) {
193		fprintf(stderr, "bad direction \"%s\"\n", *cpp);
194		return 1;
195	}
196
197#ifdef USE_INET6
198	if (!strcasecmp(*cpp, "out6") || !strcasecmp(*cpp, "in6")) {
199		return parseipv6(cpp, (ip6_t *)ip, ifn, out);
200	}
201#endif
202
203	*out = (TOLOWER(c) == 'o') ? 1 : 0;
204	cpp++;
205	if (!*cpp)
206		return 1;
207
208	if (!strcasecmp(*cpp, "on")) {
209		cpp++;
210		if (!*cpp)
211			return 1;
212		*ifn = strdup(*cpp++);
213		if (!*cpp)
214			return 1;
215	}
216
217	c = **cpp;
218	ip->ip_len = sizeof(ip_t);
219	if (!strcasecmp(*cpp, "tcp") || !strcasecmp(*cpp, "udp") ||
220	    !strcasecmp(*cpp, "icmp")) {
221		if (c == 't') {
222			ip->ip_p = IPPROTO_TCP;
223			ip->ip_len += sizeof(struct tcphdr);
224			tx_proto = "tcp";
225		} else if (c == 'u') {
226			ip->ip_p = IPPROTO_UDP;
227			ip->ip_len += sizeof(struct udphdr);
228			tx_proto = "udp";
229		} else {
230			ip->ip_p = IPPROTO_ICMP;
231			ip->ip_len += ICMPERR_IPICMPHLEN;
232			tx_proto = "icmp";
233		}
234		cpp++;
235	} else if (ISDIGIT(**cpp) && !index(*cpp, '.')) {
236		ip->ip_p = atoi(*cpp);
237		cpp++;
238	} else
239		ip->ip_p = IPPROTO_IP;
240
241	if (!*cpp)
242		return 1;
243	if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) {
244		char	*last;
245
246		last = strchr(*cpp, ',');
247		if (!last) {
248			fprintf(stderr, "tcp/udp with no source port\n");
249			return 1;
250		}
251		*last++ = '\0';
252		tcp->th_sport = htons(tx_portnum(last));
253		if (ip->ip_p == IPPROTO_TCP) {
254			tcp->th_win = htons(4096);
255			TCP_OFF_A(tcp, sizeof(*tcp) >> 2);
256		}
257	}
258	ip->ip_src.s_addr = tx_hostnum(*cpp, &r);
259	cpp++;
260	if (!*cpp)
261		return 1;
262
263	if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) {
264		char	*last;
265
266		last = strchr(*cpp, ',');
267		if (!last) {
268			fprintf(stderr, "tcp/udp with no destination port\n");
269			return 1;
270		}
271		*last++ = '\0';
272		tcp->th_dport = htons(tx_portnum(last));
273	}
274	ip->ip_dst.s_addr = tx_hostnum(*cpp, &r);
275	cpp++;
276	if (ip->ip_p == IPPROTO_TCP) {
277		if (*cpp != NULL) {
278			char	*s, *t;
279
280			tcp->th_flags = 0;
281			for (s = *cpp; *s; s++)
282				if ((t  = strchr(myflagset, *s)))
283					tcp->th_flags |= myflags[t-myflagset];
284			if (tcp->th_flags)
285				cpp++;
286		}
287
288		if (tcp->th_flags & TH_URG)
289			tcp->th_urp = htons(1);
290
291		if (*cpp && !strncasecmp(*cpp, "seq=", 4)) {
292			tcp->th_seq = htonl(atoi(*cpp + 4));
293			cpp++;
294		}
295
296		if (*cpp && !strncasecmp(*cpp, "ack=", 4)) {
297			tcp->th_ack = htonl(atoi(*cpp + 4));
298			cpp++;
299		}
300	} else if (*cpp && ip->ip_p == IPPROTO_ICMP) {
301		char	*t;
302
303		t = strchr(*cpp, ',');
304		if (t != NULL)
305			*t = '\0';
306
307		ic->icmp_type = geticmptype(AF_INET, *cpp);
308		if (t != NULL)
309			ic->icmp_code = atoi(t + 1);
310		cpp++;
311
312		if (ic->icmp_type == ICMP_ECHO ||
313		    ic->icmp_type == ICMP_ECHOREPLY)
314			ic->icmp_id = htons(getpid());
315		if (t != NULL)
316			*t = ',';
317	}
318
319	if (*cpp && !strcasecmp(*cpp, "opt")) {
320		u_long	olen;
321
322		cpp++;
323		olen = buildopts(*cpp, ipopts, (IP_HL(ip) - 5) << 2);
324		if (olen) {
325			bcopy(ipopts, (char *)(ip + 1), olen);
326			IP_HL_A(ip, IP_HL(ip) + (olen >> 2));
327			ip->ip_len += olen;
328		}
329	}
330	if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP)
331		bcopy((char *)tcp, ((char *)ip) + (IP_HL(ip) << 2),
332			sizeof(*tcp));
333	else if (ip->ip_p == IPPROTO_ICMP)
334		bcopy((char *)ic, ((char *)ip) + (IP_HL(ip) << 2),
335			sizeof(*ic));
336	ip->ip_len = htons(ip->ip_len);
337	return 0;
338}
339
340
341#ifdef USE_INET6
342int parseipv6(cpp, ip6, ifn, out)
343	char **cpp;
344	ip6_t *ip6;
345	char **ifn;
346	int *out;
347{
348	tcphdr_t th, *tcp = &th;
349	struct icmp6_hdr icmp, *ic6 = &icmp;
350
351	bzero((char *)ip6, MAX(sizeof(*tcp), sizeof(*ic6)) + sizeof(*ip6));
352	bzero((char *)tcp, sizeof(*tcp));
353	bzero((char *)ic6, sizeof(*ic6));
354	ip6->ip6_vfc = 0x60;
355
356	*out = (**cpp == 'o') ? 1 : 0;
357	cpp++;
358	if (!*cpp)
359		return 1;
360
361	if (!strcasecmp(*cpp, "on")) {
362		cpp++;
363		if (!*cpp)
364			return 1;
365		*ifn = strdup(*cpp++);
366		if (!*cpp)
367			return 1;
368	}
369
370	if (!strcasecmp(*cpp, "tcp")) {
371		ip6->ip6_nxt = IPPROTO_TCP;
372		tx_proto = "tcp";
373		cpp++;
374	} else if (!strcasecmp(*cpp, "udp")) {
375		ip6->ip6_nxt = IPPROTO_UDP;
376		tx_proto = "udp";
377		cpp++;
378	} else if (!strcasecmp(*cpp, "icmpv6")) {
379		ip6->ip6_nxt = IPPROTO_ICMPV6;
380		tx_proto = "icmpv6";
381		cpp++;
382	} else if (ISDIGIT(**cpp) && !index(*cpp, ':')) {
383		ip6->ip6_nxt = atoi(*cpp);
384		cpp++;
385	} else
386		ip6->ip6_nxt = IPPROTO_IPV6;
387
388	if (!*cpp)
389		return 1;
390
391	switch (ip6->ip6_nxt)
392	{
393	case IPPROTO_TCP :
394		ip6->ip6_plen = sizeof(struct tcphdr);
395		break;
396	case IPPROTO_UDP :
397		ip6->ip6_plen = sizeof(struct udphdr);
398		break;
399	case IPPROTO_ICMPV6 :
400		ip6->ip6_plen = ICMP6ERR_IPICMPHLEN;
401		break;
402	default :
403		break;
404	}
405
406	if (ip6->ip6_nxt == IPPROTO_TCP || ip6->ip6_nxt == IPPROTO_UDP) {
407		char *last;
408
409		last = strchr(*cpp, ',');
410		if (!last) {
411			fprintf(stderr, "tcp/udp with no source port\n");
412			return 1;
413		}
414		*last++ = '\0';
415		tcp->th_sport = htons(tx_portnum(last));
416		if (ip6->ip6_nxt == IPPROTO_TCP) {
417			tcp->th_win = htons(4096);
418			TCP_OFF_A(tcp, sizeof(*tcp) >> 2);
419		}
420	}
421
422	if (inet_pton(AF_INET6, *cpp, &ip6->ip6_src) != 1) {
423		fprintf(stderr, "cannot parse source address '%s'\n", *cpp);
424		return 1;
425	}
426
427	cpp++;
428	if (!*cpp)
429		return 1;
430
431	if (ip6->ip6_nxt == IPPROTO_TCP || ip6->ip6_nxt == IPPROTO_UDP) {
432		char *last;
433
434		last = strchr(*cpp, ',');
435		if (!last) {
436			fprintf(stderr, "tcp/udp with no destination port\n");
437			return 1;
438		}
439		*last++ = '\0';
440		tcp->th_dport = htons(tx_portnum(last));
441	}
442
443	if (inet_pton(AF_INET6, *cpp, &ip6->ip6_dst) != 1) {
444		fprintf(stderr, "cannot parse destination address '%s'\n",
445			*cpp);
446		return 1;
447	}
448
449	cpp++;
450	if (ip6->ip6_nxt == IPPROTO_TCP) {
451		if (*cpp != NULL) {
452			char *s, *t;
453
454			tcp->th_flags = 0;
455			for (s = *cpp; *s; s++)
456				if ((t  = strchr(myflagset, *s)))
457					tcp->th_flags |= myflags[t-myflagset];
458			if (tcp->th_flags)
459				cpp++;
460		}
461
462		if (tcp->th_flags & TH_URG)
463			tcp->th_urp = htons(1);
464
465		if (*cpp && !strncasecmp(*cpp, "seq=", 4)) {
466			tcp->th_seq = htonl(atoi(*cpp + 4));
467			cpp++;
468		}
469
470		if (*cpp && !strncasecmp(*cpp, "ack=", 4)) {
471			tcp->th_ack = htonl(atoi(*cpp + 4));
472			cpp++;
473		}
474	} else if (*cpp && ip6->ip6_nxt == IPPROTO_ICMPV6) {
475		char *t;
476
477		t = strchr(*cpp, ',');
478		if (t != NULL)
479			*t = '\0';
480
481		ic6->icmp6_type = geticmptype(AF_INET6, *cpp);
482		if (t != NULL)
483			ic6->icmp6_code = atoi(t + 1);
484
485		if (ic6->icmp6_type == ICMP6_ECHO_REQUEST ||
486		    ic6->icmp6_type == ICMP6_ECHO_REPLY)
487			ic6->icmp6_id = htons(getpid());
488
489		if (t != NULL)
490			*t = ',';
491	}
492
493	if (ip6->ip6_nxt == IPPROTO_TCP || ip6->ip6_nxt == IPPROTO_UDP) {
494		bcopy((char *)tcp, (char *)ip6 + sizeof(*ip6),
495			sizeof(*tcp));
496	} else if (ip6->ip6_nxt == IPPROTO_ICMPV6) {
497		bcopy((char *)ic6, (char *)ip6 + sizeof(*ip6),
498			sizeof(*ic6));
499	}
500
501	/*
502	 * Because a length of 0 == jumbo gram...
503	 */
504	if (ip6->ip6_plen == 0) {
505		ip6->ip6_plen++;
506	}
507	ip6->ip6_plen = htons(ip6->ip6_plen);
508	return 0;
509}
510#endif
511