1 /* $NetBSD: ipft_tx.c,v 1.4 2018/02/04 08:19:42 mrg Exp $ */
2
3 /*
4 * Copyright (C) 2012 by Darren Reed.
5 *
6 * See the IPFILTER.LICENCE file for details on licencing.
7 *
8 * Id: ipft_tx.c,v 1.1.1.2 2012/07/22 13:44:39 darrenr Exp $
9 */
10 #if !defined(lint)
11 static __attribute__((__used__)) const char sccsid[] = "@(#)ipft_tx.c 1.7 6/5/96 (C) 1993 Darren Reed";
12 static __attribute__((__used__)) const char rcsid[] = "@(#)Id: ipft_tx.c,v 1.1.1.2 2012/07/22 13:44:39 darrenr Exp $";
13 #endif
14
15 #include <ctype.h>
16
17 #include "ipf.h"
18 #include "ipt.h"
19
20 extern int opts;
21
22 static char *tx_proto = "";
23
24 static int text_open __P((char *)), text_close __P((void));
25 static int text_readip __P((mb_t *, char **, int *));
26 static int parseline __P((char *, ip_t *, char **, int *));
27
28 static char myflagset[] = "FSRPAUEC";
29 static u_char myflags[] = { TH_FIN, TH_SYN, TH_RST, TH_PUSH,
30 TH_ACK, TH_URG, TH_ECN, TH_CWR };
31
32 struct ipread iptext = { text_open, text_close, text_readip, R_DO_CKSUM };
33 static FILE *tfp = NULL;
34 static int tfd = -1;
35
36 static u_32_t tx_hostnum __P((char *, int *));
37 static u_short tx_portnum __P((char *));
38
39 #ifdef USE_INET6
40 int parseipv6 __P((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 */
tx_hostnum(host,resolved)47 static 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 */
tx_portnum(name)72 static 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
text_open(fname)87 static 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
text_close()107 static int text_close()
108 {
109 int cfd = tfd;
110
111 tfd = -1;
112 return close(cfd);
113 }
114
115
text_readip(mb,ifn,dir)116 static 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
126 buf = (char *)mb->mb_buf;
127
128 *ifn = NULL;
129 while (fgets(line, sizeof(line)-1, tfp)) {
130 if ((s = strchr(line, '\n')))
131 *s = '\0';
132 if ((s = strchr(line, '\r')))
133 *s = '\0';
134 if ((s = strchr(line, '#')))
135 *s = '\0';
136 if (!*line)
137 continue;
138 if ((opts & OPT_DEBUG) != 0)
139 printf("input: %s\n", line);
140 *ifn = NULL;
141 *dir = 0;
142 if (!parseline(line, (ip_t *)buf, ifn, dir)) {
143 ip = (ip_t *)buf;
144 if (IP_V(ip) == 6) {
145 #ifdef USE_INET6
146 mb->mb_len = ntohs(((ip6_t *)ip)->ip6_plen) +
147 sizeof(ip6_t);
148 #else
149 mb->mb_len = 0;
150 #endif
151 } else {
152 mb->mb_len = ntohs(ip->ip_len);
153 }
154 return mb->mb_len;
155 }
156 }
157 if (feof(tfp))
158 return 0;
159 return -1;
160 }
161
parseline(line,ip,ifn,out)162 static int parseline(line, ip, ifn, out)
163 char *line;
164 ip_t *ip;
165 char **ifn;
166 int *out;
167 {
168 tcphdr_t th, *tcp = &th;
169 struct icmp icmp, *ic = &icmp;
170 char *cps[20], **cpp, c, ipopts[68];
171 int i, r;
172
173 if (*ifn)
174 free(*ifn);
175 bzero((char *)ip, MAX(sizeof(*tcp), sizeof(*ic)) + sizeof(*ip));
176 bzero((char *)tcp, sizeof(*tcp));
177 bzero((char *)ic, sizeof(*ic));
178 bzero(ipopts, sizeof(ipopts));
179 IP_HL_A(ip, sizeof(*ip) >> 2);
180 IP_V_A(ip, IPVERSION);
181 ip->ip_ttl = 63;
182 for (i = 0, cps[0] = strtok(line, " \b\t\r\n"); cps[i] && i < 19; )
183 cps[++i] = strtok(NULL, " \b\t\r\n");
184
185 cpp = cps;
186 if (!*cpp)
187 return 1;
188
189 c = **cpp;
190 if (!ISALPHA(c) || (TOLOWER(c) != 'o' && TOLOWER(c) != 'i')) {
191 fprintf(stderr, "bad direction \"%s\"\n", *cpp);
192 return 1;
193 }
194
195 #ifdef USE_INET6
196 if (!strcasecmp(*cpp, "out6") || !strcasecmp(*cpp, "in6")) {
197 return parseipv6(cpp, (ip6_t *)ip, ifn, out);
198 }
199 #endif
200
201 *out = (TOLOWER(c) == 'o') ? 1 : 0;
202 cpp++;
203 if (!*cpp)
204 return 1;
205
206 if (!strcasecmp(*cpp, "on")) {
207 cpp++;
208 if (!*cpp)
209 return 1;
210 *ifn = strdup(*cpp++);
211 if (!*cpp)
212 return 1;
213 }
214
215 c = **cpp;
216 ip->ip_len = sizeof(ip_t);
217 if (!strcasecmp(*cpp, "tcp") || !strcasecmp(*cpp, "udp") ||
218 !strcasecmp(*cpp, "icmp")) {
219 if (c == 't') {
220 ip->ip_p = IPPROTO_TCP;
221 ip->ip_len += sizeof(struct tcphdr);
222 tx_proto = "tcp";
223 } else if (c == 'u') {
224 ip->ip_p = IPPROTO_UDP;
225 ip->ip_len += sizeof(struct udphdr);
226 tx_proto = "udp";
227 } else {
228 ip->ip_p = IPPROTO_ICMP;
229 ip->ip_len += ICMPERR_IPICMPHLEN;
230 tx_proto = "icmp";
231 }
232 cpp++;
233 } else if (ISDIGIT(**cpp) && !index(*cpp, '.')) {
234 ip->ip_p = atoi(*cpp);
235 cpp++;
236 } else
237 ip->ip_p = IPPROTO_IP;
238
239 if (!*cpp)
240 return 1;
241 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) {
242 char *last;
243
244 last = strchr(*cpp, ',');
245 if (!last) {
246 fprintf(stderr, "tcp/udp with no source port\n");
247 return 1;
248 }
249 *last++ = '\0';
250 tcp->th_sport = htons(tx_portnum(last));
251 if (ip->ip_p == IPPROTO_TCP) {
252 tcp->th_win = htons(4096);
253 TCP_OFF_A(tcp, sizeof(*tcp) >> 2);
254 }
255 }
256 ip->ip_src.s_addr = tx_hostnum(*cpp, &r);
257 cpp++;
258 if (!*cpp)
259 return 1;
260
261 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP) {
262 char *last;
263
264 last = strchr(*cpp, ',');
265 if (!last) {
266 fprintf(stderr, "tcp/udp with no destination port\n");
267 return 1;
268 }
269 *last++ = '\0';
270 tcp->th_dport = htons(tx_portnum(last));
271 }
272 ip->ip_dst.s_addr = tx_hostnum(*cpp, &r);
273 cpp++;
274 if (ip->ip_p == IPPROTO_TCP) {
275 if (*cpp != NULL) {
276 char *s, *t;
277
278 tcp->th_flags = 0;
279 for (s = *cpp; *s; s++)
280 if ((t = strchr(myflagset, *s)))
281 tcp->th_flags |= myflags[t-myflagset];
282 if (tcp->th_flags)
283 cpp++;
284 }
285
286 if (tcp->th_flags & TH_URG)
287 tcp->th_urp = htons(1);
288
289 if (*cpp && !strncasecmp(*cpp, "seq=", 4)) {
290 tcp->th_seq = htonl(atoi(*cpp + 4));
291 cpp++;
292 }
293
294 if (*cpp && !strncasecmp(*cpp, "ack=", 4)) {
295 tcp->th_ack = htonl(atoi(*cpp + 4));
296 cpp++;
297 }
298 } else if (*cpp && ip->ip_p == IPPROTO_ICMP) {
299 char *t;
300
301 t = strchr(*cpp, ',');
302 if (t != NULL)
303 *t = '\0';
304
305 ic->icmp_type = geticmptype(AF_INET, *cpp);
306 if (t != NULL)
307 ic->icmp_code = atoi(t + 1);
308 cpp++;
309
310 if (ic->icmp_type == ICMP_ECHO ||
311 ic->icmp_type == ICMP_ECHOREPLY)
312 ic->icmp_id = htons(getpid());
313 if (t != NULL)
314 *t = ',';
315 }
316
317 if (*cpp && !strcasecmp(*cpp, "opt")) {
318 u_long olen;
319
320 cpp++;
321 olen = buildopts(*cpp, ipopts, (IP_HL(ip) - 5) << 2);
322 if (olen) {
323 bcopy(ipopts, (char *)(ip + 1), olen);
324 IP_HL_A(ip, IP_HL(ip) + (olen >> 2));
325 ip->ip_len += olen;
326 }
327 }
328 if (ip->ip_p == IPPROTO_TCP || ip->ip_p == IPPROTO_UDP)
329 bcopy((char *)tcp, ((char *)ip) + (IP_HL(ip) << 2),
330 sizeof(*tcp));
331 else if (ip->ip_p == IPPROTO_ICMP)
332 bcopy((char *)ic, ((char *)ip) + (IP_HL(ip) << 2),
333 sizeof(*ic));
334 ip->ip_len = htons(ip->ip_len);
335 return 0;
336 }
337
338
339 #ifdef USE_INET6
parseipv6(cpp,ip6,ifn,out)340 int parseipv6(cpp, ip6, ifn, out)
341 char **cpp;
342 ip6_t *ip6;
343 char **ifn;
344 int *out;
345 {
346 tcphdr_t th, *tcp = &th;
347 struct icmp6_hdr icmp, *ic6 = &icmp;
348
349 bzero((char *)ip6, MAX(sizeof(*tcp), sizeof(*ic6)) + sizeof(*ip6));
350 bzero((char *)tcp, sizeof(*tcp));
351 bzero((char *)ic6, sizeof(*ic6));
352 ip6->ip6_vfc = 0x60;
353
354 *out = (**cpp == 'o') ? 1 : 0;
355 cpp++;
356 if (!*cpp)
357 return 1;
358
359 if (!strcasecmp(*cpp, "on")) {
360 cpp++;
361 if (!*cpp)
362 return 1;
363 *ifn = strdup(*cpp++);
364 if (!*cpp)
365 return 1;
366 }
367
368 if (!strcasecmp(*cpp, "tcp")) {
369 ip6->ip6_nxt = IPPROTO_TCP;
370 tx_proto = "tcp";
371 cpp++;
372 } else if (!strcasecmp(*cpp, "udp")) {
373 ip6->ip6_nxt = IPPROTO_UDP;
374 tx_proto = "udp";
375 cpp++;
376 } else if (!strcasecmp(*cpp, "icmpv6")) {
377 ip6->ip6_nxt = IPPROTO_ICMPV6;
378 tx_proto = "icmpv6";
379 cpp++;
380 } else if (ISDIGIT(**cpp) && !index(*cpp, ':')) {
381 ip6->ip6_nxt = atoi(*cpp);
382 cpp++;
383 } else
384 ip6->ip6_nxt = IPPROTO_IPV6;
385
386 if (!*cpp)
387 return 1;
388
389 switch (ip6->ip6_nxt)
390 {
391 case IPPROTO_TCP :
392 ip6->ip6_plen = sizeof(struct tcphdr);
393 break;
394 case IPPROTO_UDP :
395 ip6->ip6_plen = sizeof(struct udphdr);
396 break;
397 case IPPROTO_ICMPV6 :
398 ip6->ip6_plen = ICMP6ERR_IPICMPHLEN;
399 break;
400 default :
401 break;
402 }
403
404 if (ip6->ip6_nxt == IPPROTO_TCP || ip6->ip6_nxt == IPPROTO_UDP) {
405 char *last;
406
407 last = strchr(*cpp, ',');
408 if (!last) {
409 fprintf(stderr, "tcp/udp with no source port\n");
410 return 1;
411 }
412 *last++ = '\0';
413 tcp->th_sport = htons(tx_portnum(last));
414 if (ip6->ip6_nxt == IPPROTO_TCP) {
415 tcp->th_win = htons(4096);
416 TCP_OFF_A(tcp, sizeof(*tcp) >> 2);
417 }
418 }
419
420 if (inet_pton(AF_INET6, *cpp, &ip6->ip6_src) != 1) {
421 fprintf(stderr, "cannot parse source address '%s'\n", *cpp);
422 return 1;
423 }
424
425 cpp++;
426 if (!*cpp)
427 return 1;
428
429 if (ip6->ip6_nxt == IPPROTO_TCP || ip6->ip6_nxt == IPPROTO_UDP) {
430 char *last;
431
432 last = strchr(*cpp, ',');
433 if (!last) {
434 fprintf(stderr, "tcp/udp with no destination port\n");
435 return 1;
436 }
437 *last++ = '\0';
438 tcp->th_dport = htons(tx_portnum(last));
439 }
440
441 if (inet_pton(AF_INET6, *cpp, &ip6->ip6_dst) != 1) {
442 fprintf(stderr, "cannot parse destination address '%s'\n",
443 *cpp);
444 return 1;
445 }
446
447 cpp++;
448 if (ip6->ip6_nxt == IPPROTO_TCP) {
449 if (*cpp != NULL) {
450 char *s, *t;
451
452 tcp->th_flags = 0;
453 for (s = *cpp; *s; s++)
454 if ((t = strchr(myflagset, *s)))
455 tcp->th_flags |= myflags[t-myflagset];
456 if (tcp->th_flags)
457 cpp++;
458 }
459
460 if (tcp->th_flags & TH_URG)
461 tcp->th_urp = htons(1);
462
463 if (*cpp && !strncasecmp(*cpp, "seq=", 4)) {
464 tcp->th_seq = htonl(atoi(*cpp + 4));
465 cpp++;
466 }
467
468 if (*cpp && !strncasecmp(*cpp, "ack=", 4)) {
469 tcp->th_ack = htonl(atoi(*cpp + 4));
470 cpp++;
471 }
472 } else if (*cpp && ip6->ip6_nxt == IPPROTO_ICMPV6) {
473 char *t;
474
475 t = strchr(*cpp, ',');
476 if (t != NULL)
477 *t = '\0';
478
479 ic6->icmp6_type = geticmptype(AF_INET6, *cpp);
480 if (t != NULL)
481 ic6->icmp6_code = atoi(t + 1);
482
483 if (ic6->icmp6_type == ICMP6_ECHO_REQUEST ||
484 ic6->icmp6_type == ICMP6_ECHO_REPLY)
485 ic6->icmp6_id = htons(getpid());
486
487 if (t != NULL)
488 *t = ',';
489 }
490
491 if (ip6->ip6_nxt == IPPROTO_TCP || ip6->ip6_nxt == IPPROTO_UDP) {
492 bcopy((char *)tcp, (char *)ip6 + sizeof(*ip6),
493 sizeof(*tcp));
494 } else if (ip6->ip6_nxt == IPPROTO_ICMPV6) {
495 bcopy((char *)ic6, (char *)ip6 + sizeof(*ip6),
496 sizeof(*ic6));
497 }
498
499 /*
500 * Because a length of 0 == jumbo gram...
501 */
502 if (ip6->ip6_plen == 0) {
503 ip6->ip6_plen++;
504 }
505 ip6->ip6_plen = htons(ip6->ip6_plen);
506 return 0;
507 }
508 #endif
509