1 /* $FreeBSD$ */
2
3 /*
4 * Copyright (C) 2012 by Darren Reed.
5 *
6 * See the IPFILTER.LICENCE file for details on licencing.
7 *
8 * Simple FTP transparent proxy for in-kernel use. For use with the NAT
9 * code.
10 *
11 * $FreeBSD$
12 * Id: ip_ftp_pxy.c,v 2.88.2.19 2006/04/01 10:14:53 darrenr Exp $
13 */
14
15 #define IPF_FTP_PROXY
16
17 #define IPF_MINPORTLEN 18
18 #define IPF_MINEPRTLEN 20
19 #define IPF_MAXPORTLEN 30
20 #define IPF_MIN227LEN 39
21 #define IPF_MAX227LEN 51
22 #define IPF_MIN229LEN 47
23 #define IPF_MAX229LEN 51
24
25 #define FTPXY_GO 0
26 #define FTPXY_INIT 1
27 #define FTPXY_USER_1 2
28 #define FTPXY_USOK_1 3
29 #define FTPXY_PASS_1 4
30 #define FTPXY_PAOK_1 5
31 #define FTPXY_AUTH_1 6
32 #define FTPXY_AUOK_1 7
33 #define FTPXY_ADAT_1 8
34 #define FTPXY_ADOK_1 9
35 #define FTPXY_ACCT_1 10
36 #define FTPXY_ACOK_1 11
37 #define FTPXY_USER_2 12
38 #define FTPXY_USOK_2 13
39 #define FTPXY_PASS_2 14
40 #define FTPXY_PAOK_2 15
41
42 #define FTPXY_JUNK_OK 0
43 #define FTPXY_JUNK_BAD 1 /* Ignore all commands for this connection */
44 #define FTPXY_JUNK_EOL 2 /* consume the rest of this line only */
45 #define FTPXY_JUNK_CONT 3 /* Saerching for next numeric */
46
47 /*
48 * Values for FTP commands. Numerics cover 0-999
49 */
50 #define FTPXY_C_PASV 1000
51 #define FTPXY_C_PORT 1001
52 #define FTPXY_C_EPSV 1002
53 #define FTPXY_C_EPRT 1003
54
55
56 typedef struct ipf_ftp_softc_s {
57 int ipf_p_ftp_pasvonly;
58 /* Do not require logins before transfers */
59 int ipf_p_ftp_insecure;
60 int ipf_p_ftp_pasvrdr;
61 /* PASV must be last command prior to 227 */
62 int ipf_p_ftp_forcepasv;
63 int ipf_p_ftp_debug;
64 int ipf_p_ftp_single_xfer;
65 void *ipf_p_ftp_tune;
66 } ipf_ftp_softc_t;
67
68
69 void ipf_p_ftp_main_load __P((void));
70 void ipf_p_ftp_main_unload __P((void));
71 void *ipf_p_ftp_soft_create __P((ipf_main_softc_t *));
72 void ipf_p_ftp_soft_destroy __P((ipf_main_softc_t *, void *));
73
74 int ipf_p_ftp_client __P((ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
75 ftpinfo_t *, int));
76 int ipf_p_ftp_complete __P((char *, size_t));
77 int ipf_p_ftp_in __P((void *, fr_info_t *, ap_session_t *, nat_t *));
78 int ipf_p_ftp_new __P((void *, fr_info_t *, ap_session_t *, nat_t *));
79 void ipf_p_ftp_del __P((ipf_main_softc_t *, ap_session_t *));
80 int ipf_p_ftp_out __P((void *, fr_info_t *, ap_session_t *, nat_t *));
81 int ipf_p_ftp_pasv __P((ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
82 ftpinfo_t *, int));
83 int ipf_p_ftp_epsv __P((ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
84 ftpinfo_t *, int));
85 int ipf_p_ftp_port __P((ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
86 ftpinfo_t *, int));
87 int ipf_p_ftp_process __P((ipf_ftp_softc_t *, fr_info_t *, nat_t *,
88 ftpinfo_t *, int));
89 int ipf_p_ftp_server __P((ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
90 ftpinfo_t *, int));
91 int ipf_p_ftp_valid __P((ipf_ftp_softc_t *, ftpinfo_t *, int, char *, size_t));
92 int ipf_p_ftp_server_valid __P((ipf_ftp_softc_t *, ftpside_t *, char *,
93 size_t));
94 int ipf_p_ftp_client_valid __P((ipf_ftp_softc_t *, ftpside_t *, char *,
95 size_t));
96 u_short ipf_p_ftp_atoi __P((char **));
97 int ipf_p_ftp_pasvreply __P((ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
98 ftpinfo_t *, u_int, char *, char *));
99 int ipf_p_ftp_eprt __P((ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
100 ftpinfo_t *, int));
101 int ipf_p_ftp_eprt4 __P((ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
102 ftpinfo_t *, int));
103 int ipf_p_ftp_eprt6 __P((ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
104 ftpinfo_t *, int));
105 int ipf_p_ftp_addport __P((ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
106 ftpinfo_t *, int, int, int));
107 void ipf_p_ftp_setpending __P((ipf_main_softc_t *, ftpinfo_t *));
108
109 /*
110 * Debug levels
111 */
112 #define DEBUG_SECURITY 0x01
113 #define DEBUG_ERROR 0x02
114 #define DEBUG_INFO 0x04
115 #define DEBUG_PARSE_ERR 0x08
116 #define DEBUG_PARSE_INFO 0x10
117 #define DEBUG_PARSE 0x20
118
119 static int ipf_p_ftp_proxy_init = 0;
120 static frentry_t ftppxyfr;
121 static ipftuneable_t ipf_ftp_tuneables[] = {
122 { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_debug) },
123 "ftp_debug", 0, 0x7f,
124 stsizeof(ipf_ftp_softc_t, ipf_p_ftp_debug),
125 0, NULL, NULL },
126 { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_pasvonly) },
127 "ftp_pasvonly", 0, 1,
128 stsizeof(ipf_ftp_softc_t, ipf_p_ftp_pasvonly),
129 0, NULL, NULL },
130 { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_insecure) },
131 "ftp_insecure", 0, 1,
132 stsizeof(ipf_ftp_softc_t, ipf_p_ftp_insecure),
133 0, NULL, NULL },
134 { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_pasvrdr) },
135 "ftp_pasvrdr", 0, 1,
136 stsizeof(ipf_ftp_softc_t, ipf_p_ftp_pasvrdr),
137 0, NULL, NULL },
138 { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_forcepasv) },
139 "ftp_forcepasv", 0, 1,
140 stsizeof(ipf_ftp_softc_t, ipf_p_ftp_forcepasv),
141 0, NULL, NULL },
142 { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_single_xfer) },
143 "ftp_single_xfer", 0, 1,
144 stsizeof(ipf_ftp_softc_t, ipf_p_ftp_single_xfer),
145 0, NULL, NULL },
146 { { NULL }, NULL, 0, 0, 0, 0, NULL, NULL }
147 };
148
149
150 void
ipf_p_ftp_main_load()151 ipf_p_ftp_main_load()
152 {
153 bzero((char *)&ftppxyfr, sizeof(ftppxyfr));
154 ftppxyfr.fr_ref = 1;
155 ftppxyfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
156
157 MUTEX_INIT(&ftppxyfr.fr_lock, "FTP Proxy Mutex");
158 ipf_p_ftp_proxy_init = 1;
159 }
160
161
162 void
ipf_p_ftp_main_unload()163 ipf_p_ftp_main_unload()
164 {
165
166 if (ipf_p_ftp_proxy_init == 1) {
167 MUTEX_DESTROY(&ftppxyfr.fr_lock);
168 ipf_p_ftp_proxy_init = 0;
169 }
170 }
171
172
173 /*
174 * Initialize local structures.
175 */
176 void *
ipf_p_ftp_soft_create(softc)177 ipf_p_ftp_soft_create(softc)
178 ipf_main_softc_t *softc;
179 {
180 ipf_ftp_softc_t *softf;
181
182 KMALLOC(softf, ipf_ftp_softc_t *);
183 if (softf == NULL)
184 return NULL;
185
186 bzero((char *)softf, sizeof(*softf));
187 #if defined(_KERNEL)
188 softf->ipf_p_ftp_debug = 0;
189 #else
190 softf->ipf_p_ftp_debug = DEBUG_PARSE_ERR;
191 #endif
192 softf->ipf_p_ftp_forcepasv = 1;
193
194 softf->ipf_p_ftp_tune = ipf_tune_array_copy(softf,
195 sizeof(ipf_ftp_tuneables),
196 ipf_ftp_tuneables);
197 if (softf->ipf_p_ftp_tune == NULL) {
198 ipf_p_ftp_soft_destroy(softc, softf);
199 return NULL;
200 }
201 if (ipf_tune_array_link(softc, softf->ipf_p_ftp_tune) == -1) {
202 ipf_p_ftp_soft_destroy(softc, softf);
203 return NULL;
204 }
205
206 return softf;
207 }
208
209
210 void
ipf_p_ftp_soft_destroy(softc,arg)211 ipf_p_ftp_soft_destroy(softc, arg)
212 ipf_main_softc_t *softc;
213 void *arg;
214 {
215 ipf_ftp_softc_t *softf = arg;
216
217 if (softf->ipf_p_ftp_tune != NULL) {
218 ipf_tune_array_unlink(softc, softf->ipf_p_ftp_tune);
219 KFREES(softf->ipf_p_ftp_tune, sizeof(ipf_ftp_tuneables));
220 softf->ipf_p_ftp_tune = NULL;
221 }
222
223 KFREE(softf);
224 }
225
226
227 int
ipf_p_ftp_new(arg,fin,aps,nat)228 ipf_p_ftp_new(arg, fin, aps, nat)
229 void *arg;
230 fr_info_t *fin;
231 ap_session_t *aps;
232 nat_t *nat;
233 {
234 ftpinfo_t *ftp;
235 ftpside_t *f;
236
237 KMALLOC(ftp, ftpinfo_t *);
238 if (ftp == NULL)
239 return -1;
240
241 nat = nat; /* LINT */
242
243 aps->aps_data = ftp;
244 aps->aps_psiz = sizeof(ftpinfo_t);
245 aps->aps_sport = htons(fin->fin_sport);
246 aps->aps_dport = htons(fin->fin_dport);
247
248 bzero((char *)ftp, sizeof(*ftp));
249 f = &ftp->ftp_side[0];
250 f->ftps_rptr = f->ftps_buf;
251 f->ftps_wptr = f->ftps_buf;
252 f = &ftp->ftp_side[1];
253 f->ftps_rptr = f->ftps_buf;
254 f->ftps_wptr = f->ftps_buf;
255 ftp->ftp_passok = FTPXY_INIT;
256 ftp->ftp_incok = 0;
257 return 0;
258 }
259
260
261 void
ipf_p_ftp_setpending(ipf_main_softc_t * softc,ftpinfo_t * ftp)262 ipf_p_ftp_setpending(ipf_main_softc_t *softc, ftpinfo_t *ftp)
263 {
264 if (ftp->ftp_pendnat != NULL)
265 ipf_nat_setpending(softc, ftp->ftp_pendnat);
266
267 if (ftp->ftp_pendstate != NULL) {
268 READ_ENTER(&softc->ipf_state);
269 ipf_state_setpending(softc, ftp->ftp_pendstate);
270 RWLOCK_EXIT(&softc->ipf_state);
271 }
272 }
273
274
275 void
ipf_p_ftp_del(softc,aps)276 ipf_p_ftp_del(softc, aps)
277 ipf_main_softc_t *softc;
278 ap_session_t *aps;
279 {
280 ftpinfo_t *ftp;
281
282 ftp = aps->aps_data;
283 if (ftp != NULL)
284 ipf_p_ftp_setpending(softc, ftp);
285 }
286
287
288 int
ipf_p_ftp_port(softf,fin,ip,nat,ftp,dlen)289 ipf_p_ftp_port(softf, fin, ip, nat, ftp, dlen)
290 ipf_ftp_softc_t *softf;
291 fr_info_t *fin;
292 ip_t *ip;
293 nat_t *nat;
294 ftpinfo_t *ftp;
295 int dlen;
296 {
297 char newbuf[IPF_FTPBUFSZ], *s;
298 u_int a1, a2, a3, a4;
299 u_short a5, a6, sp;
300 size_t nlen, olen;
301 tcphdr_t *tcp;
302 int inc, off;
303 ftpside_t *f;
304 mb_t *m;
305
306 m = fin->fin_m;
307 f = &ftp->ftp_side[0];
308 tcp = (tcphdr_t *)fin->fin_dp;
309 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
310
311 /*
312 * Check for client sending out PORT message.
313 */
314 if (dlen < IPF_MINPORTLEN) {
315 DT3(ftp_PORT_error_dlen, nat_t *, nat, ftpside_t *, f,
316 u_int, dlen);
317 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
318 printf("ipf_p_ftp_port:dlen(%d) < IPF_MINPORTLEN\n",
319 dlen);
320 return 0;
321 }
322 /*
323 * Skip the PORT command + space
324 */
325 s = f->ftps_rptr + 5;
326 /*
327 * Pick out the address components, two at a time.
328 */
329 a1 = ipf_p_ftp_atoi(&s);
330 if (s == NULL) {
331 DT2(ftp_PORT_error_atoi_1, nat_t *, nat, ftpside_t *, f);
332 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
333 printf("ipf_p_ftp_port:ipf_p_ftp_atoi(%d) failed\n", 1);
334 return 0;
335 }
336 a2 = ipf_p_ftp_atoi(&s);
337 if (s == NULL) {
338 DT2(ftp_PORT_error_atoi_2, nat_t *, nat, ftpside_t *, f);
339 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
340 printf("ipf_p_ftp_port:ipf_p_ftp_atoi(%d) failed\n", 2);
341 return 0;
342 }
343
344 /*
345 * Check that IP address in the PORT/PASV reply is the same as the
346 * sender of the command - prevents using PORT for port scanning.
347 */
348 a1 <<= 16;
349 a1 |= a2;
350 if (((nat->nat_dir == NAT_OUTBOUND) &&
351 (a1 != ntohl(nat->nat_osrcaddr))) ||
352 ((nat->nat_dir == NAT_INBOUND) &&
353 (a1 != ntohl(nat->nat_nsrcaddr)))) {
354 DT3(ftp_PORT_error_address, nat_t *, nat, ftpside_t *, f,
355 u_int, a1);
356 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
357 printf("ipf_p_ftp_port:%s != nat->nat_inip\n", "a1");
358 return APR_ERR(1);
359 }
360
361 a5 = ipf_p_ftp_atoi(&s);
362 if (s == NULL) {
363 DT2(ftp_PORT_error_atoi_3, nat_t *, nat, ftpside_t *, f);
364 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
365 printf("ipf_p_ftp_port:ipf_p_ftp_atoi(%d) failed\n", 3);
366 return 0;
367 }
368 if (*s == ')')
369 s++;
370
371 /*
372 * check for CR-LF at the end.
373 */
374 if (*s == '\n')
375 s--;
376 if ((*s != '\r') || (*(s + 1) != '\n')) {
377 DT2(ftp_PORT_error_no_crlf, nat_t *, nat, ftpside_t *, f);
378 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
379 printf("ipf_p_ftp_port:missing %s\n", "cr-lf");
380 return 0;
381 }
382 s += 2;
383 a6 = a5 & 0xff;
384
385 /*
386 * Calculate the source port. Verification of > 1024 is in
387 * ipf_p_ftp_addport.
388 */
389 a5 >>= 8;
390 a5 &= 0xff;
391 sp = a5 << 8 | a6;
392
393 /*
394 * Calculate new address parts for PORT command
395 */
396 if (nat->nat_dir == NAT_INBOUND)
397 a1 = ntohl(nat->nat_ndstaddr);
398 else
399 a1 = ntohl(ip->ip_src.s_addr);
400 a1 = ntohl(ip->ip_src.s_addr);
401 a2 = (a1 >> 16) & 0xff;
402 a3 = (a1 >> 8) & 0xff;
403 a4 = a1 & 0xff;
404 a1 >>= 24;
405 olen = s - f->ftps_rptr;
406 /* DO NOT change this to snprintf! */
407 #if defined(SNPRINTF) && defined(_KERNEL)
408 SNPRINTF(newbuf, sizeof(newbuf), "%s %u,%u,%u,%u,%u,%u\r\n",
409 "PORT", a1, a2, a3, a4, a5, a6);
410 #else
411 (void) sprintf(newbuf, "%s %u,%u,%u,%u,%u,%u\r\n",
412 "PORT", a1, a2, a3, a4, a5, a6);
413 #endif
414
415 nlen = strlen(newbuf);
416 inc = nlen - olen;
417 if ((inc + fin->fin_plen) > 65535) {
418 DT3(ftp_PORT_error_inc, nat_t *, nat, ftpside_t *, f,
419 int, inc);
420 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
421 printf("ipf_p_ftp_port:inc(%d) + ip->ip_len > 65535\n",
422 inc);
423 return 0;
424 }
425
426 #if !defined(_KERNEL)
427 M_ADJ(m, inc);
428 #else
429 /*
430 * m_adj takes care of pkthdr.len, if required and treats inc<0 to
431 * mean remove -len bytes from the end of the packet.
432 * The mbuf chain will be extended if necessary by m_copyback().
433 */
434 if (inc < 0)
435 M_ADJ(m, inc);
436 #endif /* !defined(_KERNEL) */
437 COPYBACK(m, off, nlen, newbuf);
438 fin->fin_flx |= FI_DOCKSUM;
439
440 if (inc != 0) {
441 fin->fin_plen += inc;
442 ip->ip_len = htons(fin->fin_plen);
443 fin->fin_dlen += inc;
444 }
445
446 f->ftps_cmd = FTPXY_C_PORT;
447 return ipf_p_ftp_addport(softf, fin, ip, nat, ftp, dlen, sp, inc);
448 }
449
450
451 int
ipf_p_ftp_addport(softf,fin,ip,nat,ftp,dlen,nport,inc)452 ipf_p_ftp_addport(softf, fin, ip, nat, ftp, dlen, nport, inc)
453 ipf_ftp_softc_t *softf;
454 fr_info_t *fin;
455 ip_t *ip;
456 nat_t *nat;
457 ftpinfo_t *ftp;
458 int dlen, nport, inc;
459 {
460 tcphdr_t tcph, *tcp2 = &tcph;
461 ipf_main_softc_t *softc;
462 ipf_nat_softc_t *softn;
463 int direction;
464 fr_info_t fi;
465 ipnat_t *ipn;
466 nat_t *nat2;
467 u_short sp;
468 int flags;
469
470 softc = fin->fin_main_soft;
471 softn = softc->ipf_nat_soft;
472
473 if ((ftp->ftp_pendnat != NULL) || (ftp->ftp_pendstate != NULL)) {
474 if (softf->ipf_p_ftp_single_xfer != 0) {
475 DT2(ftp_PORT_error_add_active, nat_t *, nat,
476 ftpinfo_t *, ftp);
477 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
478 printf("ipf_p_ftp_addport:xfer active %p/%p\n",
479 ftp->ftp_pendnat, ftp->ftp_pendstate);
480 return 0;
481 }
482 ipf_p_ftp_setpending(softc, ftp);
483 }
484
485 /*
486 * Add skeleton NAT entry for connection which will come back the
487 * other way.
488 */
489 sp = nport;
490 /*
491 * Don't allow the PORT command to specify a port < 1024 due to
492 * security risks.
493 */
494 if (sp < 1024) {
495 DT3(ftp_PORT_error_port, nat_t *, nat, ftpinfo_t *, ftp,
496 u_int, sp);
497 if (softf->ipf_p_ftp_debug & DEBUG_SECURITY)
498 printf("ipf_p_ftp_addport:sp(%d) < 1024\n", sp);
499 return 0;
500 }
501 /*
502 * The server may not make the connection back from port 20, but
503 * it is the most likely so use it here to check for a conflicting
504 * mapping.
505 */
506 bcopy((char *)fin, (char *)&fi, sizeof(fi));
507 fi.fin_flx |= FI_IGNORE;
508 fi.fin_data[0] = sp;
509 fi.fin_data[1] = fin->fin_data[1] - 1;
510 fi.fin_src6 = nat->nat_ndst6;
511 fi.fin_dst6 = nat->nat_nsrc6;
512
513 if (nat->nat_v[0] == 6) {
514 #ifndef USE_INET6
515 return APR_INC(inc);
516 #endif
517 }
518
519 /*
520 * Add skeleton NAT entry for connection which will come back the
521 * other way.
522 */
523 #ifdef USE_INET6
524 if (nat->nat_v[0] == 6) {
525 if (nat->nat_dir == NAT_OUTBOUND) {
526 nat2 = ipf_nat6_outlookup(&fi, IPN_TCP|NAT_SEARCH,
527 nat->nat_pr[1],
528 &nat->nat_osrc6.in6,
529 &nat->nat_odst6.in6);
530 } else {
531 nat2 = ipf_nat6_inlookup(&fi, IPN_TCP|NAT_SEARCH,
532 nat->nat_pr[0],
533 &nat->nat_odst6.in6,
534 &nat->nat_osrc6.in6);
535 }
536 } else
537 #endif
538 {
539 if (nat->nat_dir == NAT_OUTBOUND) {
540 nat2 = ipf_nat_outlookup(&fi, IPN_TCP|NAT_SEARCH,
541 nat->nat_pr[1],
542 nat->nat_osrcip,
543 nat->nat_odstip);
544 } else {
545 nat2 = ipf_nat_inlookup(&fi, IPN_TCP|NAT_SEARCH,
546 nat->nat_pr[0],
547 nat->nat_odstip,
548 nat->nat_osrcip);
549 }
550 }
551 if (nat2 != NULL)
552 return APR_INC(inc);
553
554 ipn = ipf_proxy_rule_rev(nat);
555 if (ipn == NULL)
556 return APR_ERR(1);
557 ipn->in_use = 0;
558
559 fi.fin_fr = &ftppxyfr;
560 fi.fin_dp = (char *)tcp2;
561 fi.fin_dlen = sizeof(*tcp2);
562 fi.fin_plen = fi.fin_hlen + sizeof(*tcp2);
563 fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE;
564 fi.fin_data[1] = sp;
565 fi.fin_data[0] = 0;
566
567 bzero((char *)tcp2, sizeof(*tcp2));
568 tcp2->th_sport = 0;
569 tcp2->th_dport = htons(sp);
570
571 tcp2->th_win = htons(8192);
572 TCP_OFF_A(tcp2, 5);
573 tcp2->th_flags = TH_SYN;
574
575 if (nat->nat_dir == NAT_INBOUND) {
576 fi.fin_out = 1;
577 direction = NAT_OUTBOUND;
578 } else {
579 fi.fin_out = 0;
580 direction = NAT_INBOUND;
581 }
582 flags = SI_W_SPORT|NAT_SLAVE|IPN_TCP;
583
584 MUTEX_ENTER(&softn->ipf_nat_new);
585 if (nat->nat_v[0] == 6) {
586 #ifdef USE_INET6
587 nat2 = ipf_nat6_add(&fi, ipn, &ftp->ftp_pendnat, flags,
588 direction);
589 #endif
590 } else {
591 nat2 = ipf_nat_add(&fi, ipn, &ftp->ftp_pendnat, flags,
592 direction);
593 }
594 MUTEX_EXIT(&softn->ipf_nat_new);
595
596 if (nat2 == NULL) {
597 KFREES(ipn, ipn->in_size);
598 return APR_ERR(1);
599 }
600
601 (void) ipf_nat_proto(&fi, nat2, IPN_TCP);
602 MUTEX_ENTER(&nat2->nat_lock);
603 ipf_nat_update(&fi, nat2);
604 MUTEX_EXIT(&nat2->nat_lock);
605 fi.fin_ifp = NULL;
606 if (nat2->nat_dir == NAT_INBOUND)
607 fi.fin_dst6 = nat->nat_osrc6;
608 if (ipf_state_add(softc, &fi, (ipstate_t **)&ftp->ftp_pendstate,
609 SI_W_SPORT) != 0)
610 ipf_nat_setpending(softc, nat2);
611
612 return APR_INC(inc);
613 }
614
615
616 int
ipf_p_ftp_client(softf,fin,ip,nat,ftp,dlen)617 ipf_p_ftp_client(softf, fin, ip, nat, ftp, dlen)
618 ipf_ftp_softc_t *softf;
619 fr_info_t *fin;
620 nat_t *nat;
621 ftpinfo_t *ftp;
622 ip_t *ip;
623 int dlen;
624 {
625 char *rptr, *wptr, cmd[6], c;
626 ftpside_t *f;
627 int inc, i;
628
629 inc = 0;
630 f = &ftp->ftp_side[0];
631 rptr = f->ftps_rptr;
632 wptr = f->ftps_wptr;
633
634 for (i = 0; (i < 5) && (i < dlen); i++) {
635 c = rptr[i];
636 if (ISALPHA(c)) {
637 cmd[i] = TOUPPER(c);
638 } else {
639 cmd[i] = c;
640 }
641 }
642 cmd[i] = '\0';
643
644 ftp->ftp_incok = 0;
645 DT2(ftp_client_command, char [], cmd, int, ftp->ftp_passok);
646 if (!strncmp(cmd, "USER ", 5) || !strncmp(cmd, "XAUT ", 5)) {
647 if (ftp->ftp_passok == FTPXY_ADOK_1 ||
648 ftp->ftp_passok == FTPXY_AUOK_1) {
649 ftp->ftp_passok = FTPXY_USER_2;
650 ftp->ftp_incok = 1;
651 } else {
652 ftp->ftp_passok = FTPXY_USER_1;
653 ftp->ftp_incok = 1;
654 }
655 } else if (!strncmp(cmd, "AUTH ", 5)) {
656 ftp->ftp_passok = FTPXY_AUTH_1;
657 ftp->ftp_incok = 1;
658 } else if (!strncmp(cmd, "PASS ", 5)) {
659 if (ftp->ftp_passok == FTPXY_USOK_1) {
660 ftp->ftp_passok = FTPXY_PASS_1;
661 ftp->ftp_incok = 1;
662 } else if (ftp->ftp_passok == FTPXY_USOK_2) {
663 ftp->ftp_passok = FTPXY_PASS_2;
664 ftp->ftp_incok = 1;
665 }
666 } else if ((ftp->ftp_passok == FTPXY_AUOK_1) &&
667 !strncmp(cmd, "ADAT ", 5)) {
668 ftp->ftp_passok = FTPXY_ADAT_1;
669 ftp->ftp_incok = 1;
670 } else if ((ftp->ftp_passok == FTPXY_PAOK_1 ||
671 ftp->ftp_passok == FTPXY_PAOK_2) &&
672 !strncmp(cmd, "ACCT ", 5)) {
673 ftp->ftp_passok = FTPXY_ACCT_1;
674 ftp->ftp_incok = 1;
675 } else if ((ftp->ftp_passok == FTPXY_GO) &&
676 !softf->ipf_p_ftp_pasvonly &&
677 !strncmp(cmd, "PORT ", 5)) {
678 inc = ipf_p_ftp_port(softf, fin, ip, nat, ftp, dlen);
679 } else if ((ftp->ftp_passok == FTPXY_GO) &&
680 !softf->ipf_p_ftp_pasvonly &&
681 !strncmp(cmd, "EPRT ", 5)) {
682 inc = ipf_p_ftp_eprt(softf, fin, ip, nat, ftp, dlen);
683 } else if (softf->ipf_p_ftp_insecure &&
684 !softf->ipf_p_ftp_pasvonly &&
685 !strncmp(cmd, "PORT ", 5)) {
686 inc = ipf_p_ftp_port(softf, fin, ip, nat, ftp, dlen);
687 }
688 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
689 printf("ipf_p_ftp_client: cmd[%s] passok %d incok %d inc %d\n",
690 cmd, ftp->ftp_passok, ftp->ftp_incok, inc);
691
692 DT2(ftp_client_passok, char *, cmd, int, ftp->ftp_passok);
693 while ((*rptr++ != '\n') && (rptr < wptr))
694 ;
695 f->ftps_rptr = rptr;
696 return inc;
697 }
698
699
700 int
ipf_p_ftp_pasv(softf,fin,ip,nat,ftp,dlen)701 ipf_p_ftp_pasv(softf, fin, ip, nat, ftp, dlen)
702 ipf_ftp_softc_t *softf;
703 fr_info_t *fin;
704 ip_t *ip;
705 nat_t *nat;
706 ftpinfo_t *ftp;
707 int dlen;
708 {
709 u_int a1, a2, a3, a4, data_ip;
710 char newbuf[IPF_FTPBUFSZ];
711 const char *brackets[2];
712 u_short a5, a6;
713 ftpside_t *f;
714 char *s;
715
716 if ((softf->ipf_p_ftp_forcepasv != 0) &&
717 (ftp->ftp_side[0].ftps_cmd != FTPXY_C_PASV)) {
718 DT2(ftp_PASV_error_state, nat_t *, nat, ftpinfo_t *, ftp);
719 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
720 printf("ipf_p_ftp_pasv:ftps_cmd(%d) != FTPXY_C_PASV\n",
721 ftp->ftp_side[0].ftps_cmd);
722 return 0;
723 }
724
725 f = &ftp->ftp_side[1];
726
727 #define PASV_REPLEN 24
728 /*
729 * Check for PASV reply message.
730 */
731 if (dlen < IPF_MIN227LEN) {
732 DT3(ftp_PASV_error_short, nat_t *, nat, ftpinfo_t *, ftp,
733 int, dlen);
734 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
735 printf("ipf_p_ftp_pasv:dlen(%d) < IPF_MIN227LEN\n",
736 dlen);
737 return 0;
738 } else if (strncmp(f->ftps_rptr,
739 "227 Entering Passive Mod", PASV_REPLEN)) {
740 DT2(ftp_PASV_error_string, nat_t *, nat, ftpinfo_t *, ftp);
741 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
742 printf("ipf_p_ftp_pasv:%d reply wrong\n", 227);
743 return 0;
744 }
745
746 brackets[0] = "";
747 brackets[1] = "";
748 /*
749 * Skip the PASV reply + space
750 */
751 s = f->ftps_rptr + PASV_REPLEN;
752 while (*s && !ISDIGIT(*s)) {
753 if (*s == '(') {
754 brackets[0] = "(";
755 brackets[1] = ")";
756 }
757 s++;
758 }
759
760 /*
761 * Pick out the address components, two at a time.
762 */
763 a1 = ipf_p_ftp_atoi(&s);
764 if (s == NULL) {
765 DT2(ftp_PASV_error_atoi_1, nat_t *, nat, ftpside_t *, f);
766 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
767 printf("ipf_p_ftp_pasv:ipf_p_ftp_atoi(%d) failed\n", 1);
768 return 0;
769 }
770 a2 = ipf_p_ftp_atoi(&s);
771 if (s == NULL) {
772 DT2(ftp_PASV_error_atoi_2, nat_t *, nat, ftpside_t *, f);
773 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
774 printf("ipf_p_ftp_pasv:ipf_p_ftp_atoi(%d) failed\n", 2);
775 return 0;
776 }
777
778 /*
779 * check that IP address in the PASV reply is the same as the
780 * sender of the command - prevents using PASV for port scanning.
781 */
782 a1 <<= 16;
783 a1 |= a2;
784
785 if (((nat->nat_dir == NAT_INBOUND) &&
786 (a1 != ntohl(nat->nat_ndstaddr))) ||
787 ((nat->nat_dir == NAT_OUTBOUND) &&
788 (a1 != ntohl(nat->nat_odstaddr)))) {
789 DT3(ftp_PASV_error_address, nat_t *, nat, ftpside_t *, f,
790 u_int, a1);
791 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
792 printf("ipf_p_ftp_pasv:%s != nat->nat_oip\n", "a1");
793 return 0;
794 }
795
796 a5 = ipf_p_ftp_atoi(&s);
797 if (s == NULL) {
798 DT2(ftp_PASV_error_atoi_3, nat_t *, nat, ftpside_t *, f);
799 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
800 printf("ipf_p_ftp_pasv:ipf_p_ftp_atoi(%d) failed\n", 3);
801 return 0;
802 }
803
804 if (*s == ')')
805 s++;
806 if (*s == '.')
807 s++;
808 if (*s == '\n')
809 s--;
810 /*
811 * check for CR-LF at the end.
812 */
813 if ((*s != '\r') || (*(s + 1) != '\n')) {
814 DT(pasv_missing_crlf);
815 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
816 printf("ipf_p_ftp_pasv:missing %s", "cr-lf\n");
817 return 0;
818 }
819 s += 2;
820
821 a6 = a5 & 0xff;
822 a5 >>= 8;
823 /*
824 * Calculate new address parts for 227 reply
825 */
826 if (nat->nat_dir == NAT_INBOUND) {
827 data_ip = nat->nat_odstaddr;
828 a1 = ntohl(data_ip);
829 } else
830 data_ip = htonl(a1);
831
832 a2 = (a1 >> 16) & 0xff;
833 a3 = (a1 >> 8) & 0xff;
834 a4 = a1 & 0xff;
835 a1 >>= 24;
836
837 #if defined(SNPRINTF) && defined(_KERNEL)
838 SNPRINTF(newbuf, sizeof(newbuf), "%s %s%u,%u,%u,%u,%u,%u%s\r\n",
839 "227 Entering Passive Mode", brackets[0], a1, a2, a3, a4,
840 a5, a6, brackets[1]);
841 #else
842 (void) sprintf(newbuf, "%s %s%u,%u,%u,%u,%u,%u%s\r\n",
843 "227 Entering Passive Mode", brackets[0], a1, a2, a3, a4,
844 a5, a6, brackets[1]);
845 #endif
846 return ipf_p_ftp_pasvreply(softf, fin, ip, nat, ftp, (a5 << 8 | a6),
847 newbuf, s);
848 }
849
850 int
ipf_p_ftp_pasvreply(softf,fin,ip,nat,ftp,port,newmsg,s)851 ipf_p_ftp_pasvreply(softf, fin, ip, nat, ftp, port, newmsg, s)
852 ipf_ftp_softc_t *softf;
853 fr_info_t *fin;
854 ip_t *ip;
855 nat_t *nat;
856 ftpinfo_t *ftp;
857 u_int port;
858 char *newmsg;
859 char *s;
860 {
861 int inc, off, nflags;
862 tcphdr_t *tcp, tcph, *tcp2;
863 ipf_main_softc_t *softc;
864 ipf_nat_softc_t *softn;
865 size_t nlen, olen;
866 #ifdef USE_INET6
867 ip6_t *ip6;
868 #endif
869 ipnat_t *ipn;
870 fr_info_t fi;
871 ftpside_t *f;
872 nat_t *nat2;
873 mb_t *m;
874
875 softc = fin->fin_main_soft;
876 softn = softc->ipf_nat_soft;
877
878 if ((ftp->ftp_pendnat != NULL) || (ftp->ftp_pendstate != NULL))
879 ipf_p_ftp_setpending(softc, ftp);
880
881 m = fin->fin_m;
882 tcp = (tcphdr_t *)fin->fin_dp;
883 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
884
885 tcp2 = &tcph;
886 inc = 0;
887
888 f = &ftp->ftp_side[1];
889 olen = s - f->ftps_rptr;
890 nlen = strlen(newmsg);
891 inc = nlen - olen;
892 if ((inc + fin->fin_plen) > 65535) {
893 DT3(ftp_PASV_error_inc, nat_t *, nat, ftpside_t *, f,
894 int, inc);
895 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
896 printf("ipf_p_ftp_pasv:inc(%d) + ip->ip_len > 65535\n",
897 inc);
898 return 0;
899 }
900
901 ipn = ipf_proxy_rule_fwd(nat);
902 if (ipn == NULL)
903 return APR_ERR(1);
904 ipn->in_use = 0;
905
906 /*
907 * Add skeleton NAT entry for connection which will come back the
908 * other way.
909 */
910 bzero((char *)tcp2, sizeof(*tcp2));
911 bcopy((char *)fin, (char *)&fi, sizeof(fi));
912 fi.fin_flx |= FI_IGNORE;
913 fi.fin_data[0] = 0;
914 fi.fin_data[1] = port;
915 nflags = IPN_TCP|SI_W_SPORT;
916
917 fi.fin_fr = &ftppxyfr;
918 fi.fin_dp = (char *)tcp2;
919 fi.fin_out = 1 - fin->fin_out;
920 fi.fin_dlen = sizeof(*tcp2);
921 fi.fin_src6 = nat->nat_osrc6;
922 fi.fin_dst6 = nat->nat_odst6;
923 fi.fin_plen = fi.fin_hlen + sizeof(*tcp);
924 fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE;
925
926 TCP_OFF_A(tcp2, 5);
927 tcp2->th_flags = TH_SYN;
928 tcp2->th_win = htons(8192);
929 tcp2->th_dport = htons(port);
930
931 MUTEX_ENTER(&softn->ipf_nat_new);
932 #ifdef USE_INET6
933 if (nat->nat_v[0] == 6)
934 nat2 = ipf_nat6_add(&fi, ipn, &ftp->ftp_pendnat,
935 nflags, nat->nat_dir);
936 else
937 #endif
938 nat2 = ipf_nat_add(&fi, ipn, &ftp->ftp_pendnat,
939 nflags, nat->nat_dir);
940 MUTEX_EXIT(&softn->ipf_nat_new);
941
942 if (nat2 == NULL) {
943 KFREES(ipn, ipn->in_size);
944 return APR_ERR(1);
945 }
946
947 (void) ipf_nat_proto(&fi, nat2, IPN_TCP);
948 MUTEX_ENTER(&nat2->nat_lock);
949 ipf_nat_update(&fi, nat2);
950 MUTEX_EXIT(&nat2->nat_lock);
951 fi.fin_ifp = NULL;
952 if (nat->nat_dir == NAT_INBOUND) {
953 if (nat->nat_v[0] == 6) {
954 #ifdef USE_INET6
955 fi.fin_dst6 = nat->nat_ndst6;
956 #endif
957 } else {
958 fi.fin_daddr = nat->nat_ndstaddr;
959 }
960 }
961 if (ipf_state_add(softc, &fi, (ipstate_t **)&ftp->ftp_pendstate,
962 SI_W_SPORT) != 0)
963 ipf_nat_setpending(softc, nat2);
964
965 #if !defined(_KERNEL)
966 M_ADJ(m, inc);
967 #else
968 /*
969 * m_adj takes care of pkthdr.len, if required and treats inc<0 to
970 * mean remove -len bytes from the end of the packet.
971 * The mbuf chain will be extended if necessary by m_copyback().
972 */
973 if (inc < 0)
974 M_ADJ(m, inc);
975 #endif /* !defined(_KERNEL) */
976 COPYBACK(m, off, nlen, newmsg);
977 fin->fin_flx |= FI_DOCKSUM;
978
979 if (inc != 0) {
980 fin->fin_plen += inc;
981 fin->fin_dlen += inc;
982 if (nat->nat_v[0] == 6) {
983 #ifdef USE_INET6
984 ip6 = (ip6_t *)fin->fin_ip;
985 u_short len = ntohs(ip6->ip6_plen) + inc;
986 ip6->ip6_plen = htons(len);
987 #endif
988 } else {
989 ip->ip_len = htons(fin->fin_plen);
990 }
991 }
992
993 return APR_INC(inc);
994 }
995
996
997 int
ipf_p_ftp_server(softf,fin,ip,nat,ftp,dlen)998 ipf_p_ftp_server(softf, fin, ip, nat, ftp, dlen)
999 ipf_ftp_softc_t *softf;
1000 fr_info_t *fin;
1001 ip_t *ip;
1002 nat_t *nat;
1003 ftpinfo_t *ftp;
1004 int dlen;
1005 {
1006 char *rptr, *wptr;
1007 ftpside_t *f;
1008 int inc;
1009
1010 inc = 0;
1011 f = &ftp->ftp_side[1];
1012 rptr = f->ftps_rptr;
1013 wptr = f->ftps_wptr;
1014
1015 DT2(ftp_server_response, char *, rptr, int, ftp->ftp_passok);
1016 if (*rptr == ' ')
1017 goto server_cmd_ok;
1018 if (!ISDIGIT(*rptr) || !ISDIGIT(*(rptr + 1)) || !ISDIGIT(*(rptr + 2)))
1019 return 0;
1020 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
1021 printf("ipf_p_ftp_server_1: cmd[%4.4s] passok %d\n",
1022 rptr, ftp->ftp_passok);
1023 if (ftp->ftp_passok == FTPXY_GO) {
1024 if (!strncmp(rptr, "227 ", 4))
1025 inc = ipf_p_ftp_pasv(softf, fin, ip, nat, ftp, dlen);
1026 else if (!strncmp(rptr, "229 ", 4))
1027 inc = ipf_p_ftp_epsv(softf, fin, ip, nat, ftp, dlen);
1028 else if (strncmp(rptr, "200", 3)) {
1029 /*
1030 * 200 is returned for a successful command.
1031 */
1032 ;
1033 }
1034 } else if (softf->ipf_p_ftp_insecure && !strncmp(rptr, "227 ", 4)) {
1035 inc = ipf_p_ftp_pasv(softf, fin, ip, nat, ftp, dlen);
1036 } else if (softf->ipf_p_ftp_insecure && !strncmp(rptr, "229 ", 4)) {
1037 inc = ipf_p_ftp_epsv(softf, fin, ip, nat, ftp, dlen);
1038 } else if (*rptr == '5' || *rptr == '4')
1039 ftp->ftp_passok = FTPXY_INIT;
1040 else if (ftp->ftp_incok) {
1041 if (*rptr == '3') {
1042 if (ftp->ftp_passok == FTPXY_ACCT_1)
1043 ftp->ftp_passok = FTPXY_GO;
1044 else
1045 ftp->ftp_passok++;
1046 } else if (*rptr == '2') {
1047 switch (ftp->ftp_passok)
1048 {
1049 case FTPXY_USER_1 :
1050 case FTPXY_USER_2 :
1051 case FTPXY_PASS_1 :
1052 case FTPXY_PASS_2 :
1053 case FTPXY_ACCT_1 :
1054 ftp->ftp_passok = FTPXY_GO;
1055 break;
1056 default :
1057 ftp->ftp_passok += 3;
1058 break;
1059 }
1060 }
1061 }
1062 ftp->ftp_incok = 0;
1063 server_cmd_ok:
1064 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
1065 printf("ipf_p_ftp_server_2: cmd[%4.4s] passok %d\n",
1066 rptr, ftp->ftp_passok);
1067 DT3(ftp_server_passok, char *,rptr, int, ftp->ftp_incok,
1068 int, ftp->ftp_passok);
1069
1070 while ((*rptr++ != '\n') && (rptr < wptr))
1071 ;
1072 f->ftps_rptr = rptr;
1073 return inc;
1074 }
1075
1076
1077 /*
1078 * 0 FTPXY_JUNK_OK
1079 * 1 FTPXY_JUNK_BAD
1080 * 2 FTPXY_JUNK_EOL
1081 * 3 FTPXY_JUNK_CONT
1082 *
1083 * Look to see if the buffer starts with something which we recognise as
1084 * being the correct syntax for the FTP protocol.
1085 */
1086 int
ipf_p_ftp_client_valid(softf,ftps,buf,len)1087 ipf_p_ftp_client_valid(softf, ftps, buf, len)
1088 ipf_ftp_softc_t *softf;
1089 ftpside_t *ftps;
1090 char *buf;
1091 size_t len;
1092 {
1093 register char *s, c, pc;
1094 register size_t i = len;
1095 char cmd[5];
1096
1097 s = buf;
1098
1099 if (ftps->ftps_junk == FTPXY_JUNK_BAD)
1100 return FTPXY_JUNK_BAD;
1101
1102 if (i < 5) {
1103 DT1(client_valid, int, i);
1104 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
1105 printf("ipf_p_ftp_client_valid:i(%d) < 5\n", (int)i);
1106 return 2;
1107 }
1108
1109 i--;
1110 c = *s++;
1111
1112 if (ISALPHA(c)) {
1113 cmd[0] = TOUPPER(c);
1114 c = *s++;
1115 i--;
1116 if (ISALPHA(c)) {
1117 cmd[1] = TOUPPER(c);
1118 c = *s++;
1119 i--;
1120 if (ISALPHA(c)) {
1121 cmd[2] = TOUPPER(c);
1122 c = *s++;
1123 i--;
1124 if (ISALPHA(c)) {
1125 cmd[3] = TOUPPER(c);
1126 c = *s++;
1127 i--;
1128 if ((c != ' ') && (c != '\r'))
1129 goto bad_client_command;
1130 } else if ((c != ' ') && (c != '\r'))
1131 goto bad_client_command;
1132 } else
1133 goto bad_client_command;
1134 } else
1135 goto bad_client_command;
1136 } else {
1137 bad_client_command:
1138 DT4(client_junk, int, len, int, i, int, c, char *, buf);
1139 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
1140 printf("%s:bad:junk %d len %d/%d c 0x%x buf [%*.*s]\n",
1141 "ipf_p_ftp_client_valid",
1142 ftps->ftps_junk, (int)len, (int)i, c,
1143 (int)len, (int)len, buf);
1144 return FTPXY_JUNK_BAD;
1145 }
1146
1147 for (; i; i--) {
1148 pc = c;
1149 c = *s++;
1150 if ((pc == '\r') && (c == '\n')) {
1151 cmd[4] = '\0';
1152 if (!strcmp(cmd, "PASV")) {
1153 ftps->ftps_cmd = FTPXY_C_PASV;
1154 } else if (!strcmp(cmd, "EPSV")) {
1155 ftps->ftps_cmd = FTPXY_C_EPSV;
1156 } else {
1157 ftps->ftps_cmd = 0;
1158 }
1159 return 0;
1160 }
1161 }
1162 #if !defined(_KERNEL)
1163 printf("ipf_p_ftp_client_valid:junk after cmd[%*.*s]\n",
1164 (int)len, (int)len, buf);
1165 #endif
1166 return FTPXY_JUNK_EOL;
1167 }
1168
1169
1170 int
ipf_p_ftp_server_valid(softf,ftps,buf,len)1171 ipf_p_ftp_server_valid(softf, ftps, buf, len)
1172 ipf_ftp_softc_t *softf;
1173 ftpside_t *ftps;
1174 char *buf;
1175 size_t len;
1176 {
1177 register char *s, c, pc;
1178 register size_t i = len;
1179 int cmd;
1180
1181 s = buf;
1182 cmd = 0;
1183
1184 if (ftps->ftps_junk == FTPXY_JUNK_BAD)
1185 return FTPXY_JUNK_BAD;
1186
1187 if (i < 5) {
1188 DT1(server_valid, int, i);
1189 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
1190 printf("ipf_p_ftp_servert_valid:i(%d) < 5\n", (int)i);
1191 return 2;
1192 }
1193
1194 c = *s++;
1195 i--;
1196 if (c == ' ') {
1197 cmd = -1;
1198 goto search_eol;
1199 }
1200
1201 if (ISDIGIT(c)) {
1202 cmd = (c - '0') * 100;
1203 c = *s++;
1204 i--;
1205 if (ISDIGIT(c)) {
1206 cmd += (c - '0') * 10;
1207 c = *s++;
1208 i--;
1209 if (ISDIGIT(c)) {
1210 cmd += (c - '0');
1211 c = *s++;
1212 i--;
1213 if ((c != '-') && (c != ' '))
1214 goto bad_server_command;
1215 if (c == '-')
1216 return FTPXY_JUNK_CONT;
1217 } else
1218 goto bad_server_command;
1219 } else
1220 goto bad_server_command;
1221 } else {
1222 bad_server_command:
1223 DT4(server_junk, int len, buf, int, i, int, c, char *, buf);
1224 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_INFO)
1225 printf("%s:bad:junk %d len %d/%d c 0x%x buf [%*.*s]\n",
1226 "ipf_p_ftp_server_valid",
1227 ftps->ftps_junk, (int)len, (int)i,
1228 c, (int)len, (int)len, buf);
1229 if (ftps->ftps_junk == FTPXY_JUNK_CONT)
1230 return FTPXY_JUNK_CONT;
1231 return FTPXY_JUNK_BAD;
1232 }
1233 search_eol:
1234 for (; i; i--) {
1235 pc = c;
1236 c = *s++;
1237 if ((pc == '\r') && (c == '\n')) {
1238 if (cmd == -1) {
1239 if (ftps->ftps_junk == FTPXY_JUNK_CONT)
1240 return FTPXY_JUNK_CONT;
1241 } else {
1242 ftps->ftps_cmd = cmd;
1243 }
1244 return FTPXY_JUNK_OK;
1245 }
1246 }
1247
1248 DT2(junk_eol, int, len, char *, buf);
1249 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_INFO)
1250 printf("ipf_p_ftp_server_valid:junk after cmd[%*.*s]\n",
1251 (int)len, (int)len, buf);
1252 return FTPXY_JUNK_EOL;
1253 }
1254
1255
1256 int
ipf_p_ftp_valid(softf,ftp,side,buf,len)1257 ipf_p_ftp_valid(softf, ftp, side, buf, len)
1258 ipf_ftp_softc_t *softf;
1259 ftpinfo_t *ftp;
1260 int side;
1261 char *buf;
1262 size_t len;
1263 {
1264 ftpside_t *ftps;
1265 int ret;
1266
1267 ftps = &ftp->ftp_side[side];
1268
1269 if (side == 0)
1270 ret = ipf_p_ftp_client_valid(softf, ftps, buf, len);
1271 else
1272 ret = ipf_p_ftp_server_valid(softf, ftps, buf, len);
1273 return ret;
1274 }
1275
1276
1277 /*
1278 * For map rules, the following applies:
1279 * rv == 0 for outbound processing,
1280 * rv == 1 for inbound processing.
1281 * For rdr rules, the following applies:
1282 * rv == 0 for inbound processing,
1283 * rv == 1 for outbound processing.
1284 */
1285 int
ipf_p_ftp_process(softf,fin,nat,ftp,rv)1286 ipf_p_ftp_process(softf, fin, nat, ftp, rv)
1287 ipf_ftp_softc_t *softf;
1288 fr_info_t *fin;
1289 nat_t *nat;
1290 ftpinfo_t *ftp;
1291 int rv;
1292 {
1293 int mlen, len, off, inc, i, sel, sel2, ok, ackoff, seqoff, retry;
1294 char *rptr, *wptr, *s;
1295 u_32_t thseq, thack;
1296 ap_session_t *aps;
1297 ftpside_t *f, *t;
1298 tcphdr_t *tcp;
1299 ip_t *ip;
1300 mb_t *m;
1301
1302 m = fin->fin_m;
1303 ip = fin->fin_ip;
1304 tcp = (tcphdr_t *)fin->fin_dp;
1305 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
1306
1307 f = &ftp->ftp_side[rv];
1308 t = &ftp->ftp_side[1 - rv];
1309 thseq = ntohl(tcp->th_seq);
1310 thack = ntohl(tcp->th_ack);
1311 mlen = MSGDSIZE(m) - off;
1312
1313 DT3(process_debug, tcphdr_t *, tcp, int, off, int, mlen);
1314 if (softf->ipf_p_ftp_debug & DEBUG_INFO)
1315 printf("ipf_p_ftp_process: %d:%d,%d, mlen %d flags %x\n",
1316 fin->fin_out, fin->fin_sport, fin->fin_dport,
1317 mlen, tcp->th_flags);
1318
1319 if ((mlen == 0) && ((tcp->th_flags & TH_OPENING) == TH_OPENING)) {
1320 f->ftps_seq[0] = thseq + 1;
1321 t->ftps_seq[0] = thack;
1322 return 0;
1323 } else if (mlen < 0) {
1324 return 0;
1325 }
1326
1327 aps = nat->nat_aps;
1328
1329 sel = aps->aps_sel[1 - rv];
1330 sel2 = aps->aps_sel[rv];
1331 if (rv == 1) {
1332 seqoff = aps->aps_seqoff[sel];
1333 if (aps->aps_seqmin[sel] > seqoff + thseq)
1334 seqoff = aps->aps_seqoff[!sel];
1335 ackoff = aps->aps_ackoff[sel2];
1336 if (aps->aps_ackmin[sel2] > ackoff + thack)
1337 ackoff = aps->aps_ackoff[!sel2];
1338 } else {
1339 seqoff = aps->aps_ackoff[sel];
1340 if (softf->ipf_p_ftp_debug & DEBUG_INFO)
1341 printf("seqoff %d thseq %x ackmin %x\n", seqoff, thseq,
1342 aps->aps_ackmin[sel]);
1343 if (aps->aps_ackmin[sel] > seqoff + thseq)
1344 seqoff = aps->aps_ackoff[!sel];
1345
1346 ackoff = aps->aps_seqoff[sel2];
1347 if (softf->ipf_p_ftp_debug & DEBUG_INFO)
1348 printf("ackoff %d thack %x seqmin %x\n", ackoff, thack,
1349 aps->aps_seqmin[sel2]);
1350 if (ackoff > 0) {
1351 if (aps->aps_seqmin[sel2] > ackoff + thack)
1352 ackoff = aps->aps_seqoff[!sel2];
1353 } else {
1354 if (aps->aps_seqmin[sel2] > thack)
1355 ackoff = aps->aps_seqoff[!sel2];
1356 }
1357 }
1358 if (softf->ipf_p_ftp_debug & DEBUG_INFO) {
1359 printf("%s: %x seq %x/%d ack %x/%d len %d/%d off %d\n",
1360 rv ? "IN" : "OUT", tcp->th_flags, thseq, seqoff,
1361 thack, ackoff, mlen, fin->fin_plen, off);
1362 printf("sel %d seqmin %x/%x offset %d/%d\n", sel,
1363 aps->aps_seqmin[sel], aps->aps_seqmin[sel2],
1364 aps->aps_seqoff[sel], aps->aps_seqoff[sel2]);
1365 printf("sel %d ackmin %x/%x offset %d/%d\n", sel2,
1366 aps->aps_ackmin[sel], aps->aps_ackmin[sel2],
1367 aps->aps_ackoff[sel], aps->aps_ackoff[sel2]);
1368 }
1369
1370 /*
1371 * XXX - Ideally, this packet should get dropped because we now know
1372 * that it is out of order (and there is no real danger in doing so
1373 * apart from causing packets to go through here ordered).
1374 */
1375 if (softf->ipf_p_ftp_debug & DEBUG_INFO) {
1376 printf("rv %d t:seq[0] %x seq[1] %x %d/%d\n",
1377 rv, t->ftps_seq[0], t->ftps_seq[1], seqoff, ackoff);
1378 }
1379
1380 ok = 0;
1381 if (t->ftps_seq[0] == 0) {
1382 t->ftps_seq[0] = thack;
1383 ok = 1;
1384 } else {
1385 if (ackoff == 0) {
1386 if (t->ftps_seq[0] == thack)
1387 ok = 1;
1388 else if (t->ftps_seq[1] == thack) {
1389 t->ftps_seq[0] = thack;
1390 ok = 1;
1391 }
1392 } else {
1393 if (t->ftps_seq[0] + ackoff == thack) {
1394 t->ftps_seq[0] = thack;
1395 ok = 1;
1396 } else if (t->ftps_seq[0] == thack + ackoff) {
1397 t->ftps_seq[0] = thack + ackoff;
1398 ok = 1;
1399 } else if (t->ftps_seq[1] + ackoff == thack) {
1400 t->ftps_seq[0] = thack;
1401 ok = 1;
1402 } else if (t->ftps_seq[1] == thack + ackoff) {
1403 t->ftps_seq[0] = thack + ackoff;
1404 ok = 1;
1405 }
1406 }
1407 }
1408
1409 if (softf->ipf_p_ftp_debug & DEBUG_INFO) {
1410 if (!ok)
1411 printf("%s ok\n", "not");
1412 }
1413
1414 if (!mlen) {
1415 if (t->ftps_seq[0] + ackoff != thack &&
1416 t->ftps_seq[1] + ackoff != thack) {
1417 DT3(thack, ftpside_t *t, t, int, ackoff, u_32_t, thack);
1418 if (softf->ipf_p_ftp_debug & DEBUG_ERROR) {
1419 printf("%s:seq[0](%u) + (%d) != (%u)\n",
1420 "ipf_p_ftp_process", t->ftps_seq[0],
1421 ackoff, thack);
1422 printf("%s:seq[0](%u) + (%d) != (%u)\n",
1423 "ipf_p_ftp_process", t->ftps_seq[1],
1424 ackoff, thack);
1425 }
1426 return APR_ERR(1);
1427 }
1428
1429 if (softf->ipf_p_ftp_debug & DEBUG_PARSE) {
1430 printf("ipf_p_ftp_process:f:seq[0] %x seq[1] %x\n",
1431 f->ftps_seq[0], f->ftps_seq[1]);
1432 }
1433
1434 if (tcp->th_flags & TH_FIN) {
1435 if (thseq == f->ftps_seq[1]) {
1436 f->ftps_seq[0] = f->ftps_seq[1] - seqoff;
1437 f->ftps_seq[1] = thseq + 1 - seqoff;
1438 } else {
1439 DT2(thseq, ftpside_t *t, t, u_32_t, thseq);
1440 if (softf->ipf_p_ftp_debug & DEBUG_ERROR) {
1441 printf("FIN: thseq %x seqoff %d ftps_seq %x\n",
1442 thseq, seqoff, f->ftps_seq[0]);
1443 }
1444 return APR_ERR(1);
1445 }
1446 }
1447 f->ftps_len = 0;
1448 return 0;
1449 }
1450
1451 ok = 0;
1452 if ((thseq == f->ftps_seq[0]) || (thseq == f->ftps_seq[1])) {
1453 ok = 1;
1454 /*
1455 * Retransmitted data packet.
1456 */
1457 } else if ((thseq + mlen == f->ftps_seq[0]) ||
1458 (thseq + mlen == f->ftps_seq[1])) {
1459 ok = 1;
1460 }
1461
1462 if (ok == 0) {
1463 DT3(ok_0, ftpside_t *, f, u_32_t, thseq, int, mlen);
1464 inc = thseq - f->ftps_seq[0];
1465 if (softf->ipf_p_ftp_debug & DEBUG_ERROR) {
1466 printf("inc %d sel %d rv %d\n", inc, sel, rv);
1467 printf("th_seq %x ftps_seq %x/%x\n",
1468 thseq, f->ftps_seq[0], f->ftps_seq[1]);
1469 printf("ackmin %x ackoff %d\n", aps->aps_ackmin[sel],
1470 aps->aps_ackoff[sel]);
1471 printf("seqmin %x seqoff %d\n", aps->aps_seqmin[sel],
1472 aps->aps_seqoff[sel]);
1473 }
1474
1475 return APR_ERR(1);
1476 }
1477
1478 inc = 0;
1479 rptr = f->ftps_rptr;
1480 wptr = f->ftps_wptr;
1481 f->ftps_seq[0] = thseq;
1482 f->ftps_seq[1] = f->ftps_seq[0] + mlen;
1483 f->ftps_len = mlen;
1484
1485 while (mlen > 0) {
1486 len = MIN(mlen, sizeof(f->ftps_buf) - (wptr - rptr));
1487 if (len == 0)
1488 break;
1489 COPYDATA(m, off, len, wptr);
1490 mlen -= len;
1491 off += len;
1492 wptr += len;
1493
1494 whilemore:
1495 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
1496 printf("%s:len %d/%d off %d wptr %lx junk %d [%*.*s]\n",
1497 "ipf_p_ftp_process",
1498 len, mlen, off, (u_long)wptr, f->ftps_junk,
1499 len, len, rptr);
1500
1501 f->ftps_wptr = wptr;
1502 if (f->ftps_junk != FTPXY_JUNK_OK) {
1503 i = f->ftps_junk;
1504 f->ftps_junk = ipf_p_ftp_valid(softf, ftp, rv, rptr,
1505 wptr - rptr);
1506 DT2(junk_transit, int, i, int, f->ftps_junk);
1507
1508 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
1509 printf("%s:junk %d -> %d\n",
1510 "ipf_p_ftp_process", i, f->ftps_junk);
1511
1512 if (f->ftps_junk == FTPXY_JUNK_BAD) {
1513 DT(buffer_full);
1514 if (wptr - rptr == sizeof(f->ftps_buf)) {
1515 if (softf->ipf_p_ftp_debug &
1516 DEBUG_PARSE_INFO)
1517 printf("%s:full buffer\n",
1518 "ipf_p_ftp_process");
1519 f->ftps_rptr = f->ftps_buf;
1520 f->ftps_wptr = f->ftps_buf;
1521 rptr = f->ftps_rptr;
1522 wptr = f->ftps_wptr;
1523 continue;
1524 }
1525 }
1526 }
1527
1528 while ((f->ftps_junk == FTPXY_JUNK_OK) && (wptr > rptr)) {
1529 len = wptr - rptr;
1530 f->ftps_junk = ipf_p_ftp_valid(softf, ftp, rv,
1531 rptr, len);
1532
1533 if (softf->ipf_p_ftp_debug & DEBUG_PARSE) {
1534 printf("%s=%d len %d rv %d ptr %lx/%lx ",
1535 "ipf_p_ftp_valid",
1536 f->ftps_junk, len, rv, (u_long)rptr,
1537 (u_long)wptr);
1538 printf("buf [%*.*s]\n", len, len, rptr);
1539 }
1540
1541 if (f->ftps_junk == FTPXY_JUNK_OK) {
1542 f->ftps_cmds++;
1543 f->ftps_rptr = rptr;
1544 if (rv)
1545 inc += ipf_p_ftp_server(softf, fin, ip,
1546 nat, ftp, len);
1547 else
1548 inc += ipf_p_ftp_client(softf, fin, ip,
1549 nat, ftp, len);
1550 rptr = f->ftps_rptr;
1551 wptr = f->ftps_wptr;
1552 }
1553 }
1554
1555 /*
1556 * Off to a bad start so lets just forget about using the
1557 * ftp proxy for this connection.
1558 */
1559 if ((f->ftps_cmds == 0) && (f->ftps_junk == FTPXY_JUNK_BAD)) {
1560 /* f->ftps_seq[1] += inc; */
1561
1562 DT(ftp_junk_cmd);
1563 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
1564 printf("%s:cmds == 0 junk == 1\n",
1565 "ipf_p_ftp_process");
1566 return APR_ERR(2);
1567 }
1568
1569 retry = 0;
1570 if ((f->ftps_junk != FTPXY_JUNK_OK) && (rptr < wptr)) {
1571 for (s = rptr; s < wptr; s++) {
1572 if ((*s == '\r') && (s + 1 < wptr) &&
1573 (*(s + 1) == '\n')) {
1574 rptr = s + 2;
1575 retry = 1;
1576 if (f->ftps_junk != FTPXY_JUNK_CONT)
1577 f->ftps_junk = FTPXY_JUNK_OK;
1578 break;
1579 }
1580 }
1581 }
1582
1583 if (rptr == wptr) {
1584 rptr = wptr = f->ftps_buf;
1585 } else {
1586 /*
1587 * Compact the buffer back to the start. The junk
1588 * flag should already be set and because we're not
1589 * throwing away any data, it is preserved from its
1590 * current state.
1591 */
1592 if (rptr > f->ftps_buf) {
1593 bcopy(rptr, f->ftps_buf, wptr - rptr);
1594 wptr -= rptr - f->ftps_buf;
1595 rptr = f->ftps_buf;
1596 }
1597 }
1598 f->ftps_rptr = rptr;
1599 f->ftps_wptr = wptr;
1600 if (retry)
1601 goto whilemore;
1602 }
1603
1604 /* f->ftps_seq[1] += inc; */
1605 if (tcp->th_flags & TH_FIN)
1606 f->ftps_seq[1]++;
1607 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_INFO) {
1608 mlen = MSGDSIZE(m);
1609 mlen -= off;
1610 printf("ftps_seq[1] = %x inc %d len %d\n",
1611 f->ftps_seq[1], inc, mlen);
1612 }
1613
1614 f->ftps_rptr = rptr;
1615 f->ftps_wptr = wptr;
1616 return APR_INC(inc);
1617 }
1618
1619
1620 int
ipf_p_ftp_out(arg,fin,aps,nat)1621 ipf_p_ftp_out(arg, fin, aps, nat)
1622 void *arg;
1623 fr_info_t *fin;
1624 ap_session_t *aps;
1625 nat_t *nat;
1626 {
1627 ipf_ftp_softc_t *softf = arg;
1628 ftpinfo_t *ftp;
1629 int rev;
1630
1631 ftp = aps->aps_data;
1632 if (ftp == NULL)
1633 return 0;
1634
1635 rev = (nat->nat_dir == NAT_OUTBOUND) ? 0 : 1;
1636 if (ftp->ftp_side[1 - rev].ftps_ifp == NULL)
1637 ftp->ftp_side[1 - rev].ftps_ifp = fin->fin_ifp;
1638
1639 return ipf_p_ftp_process(softf, fin, nat, ftp, rev);
1640 }
1641
1642
1643 int
ipf_p_ftp_in(arg,fin,aps,nat)1644 ipf_p_ftp_in(arg, fin, aps, nat)
1645 void *arg;
1646 fr_info_t *fin;
1647 ap_session_t *aps;
1648 nat_t *nat;
1649 {
1650 ipf_ftp_softc_t *softf = arg;
1651 ftpinfo_t *ftp;
1652 int rev;
1653
1654 ftp = aps->aps_data;
1655 if (ftp == NULL)
1656 return 0;
1657
1658 rev = (nat->nat_dir == NAT_OUTBOUND) ? 0 : 1;
1659 if (ftp->ftp_side[rev].ftps_ifp == NULL)
1660 ftp->ftp_side[rev].ftps_ifp = fin->fin_ifp;
1661
1662 return ipf_p_ftp_process(softf, fin, nat, ftp, 1 - rev);
1663 }
1664
1665
1666 /*
1667 * ipf_p_ftp_atoi - implement a version of atoi which processes numbers in
1668 * pairs separated by commas (which are expected to be in the range 0 - 255),
1669 * returning a 16 bit number combining either side of the , as the MSB and
1670 * LSB.
1671 */
1672 u_short
ipf_p_ftp_atoi(ptr)1673 ipf_p_ftp_atoi(ptr)
1674 char **ptr;
1675 {
1676 register char *s = *ptr, c;
1677 register u_char i = 0, j = 0;
1678
1679 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1680 i *= 10;
1681 i += c - '0';
1682 }
1683 if (c != ',') {
1684 *ptr = NULL;
1685 return 0;
1686 }
1687 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1688 j *= 10;
1689 j += c - '0';
1690 }
1691 *ptr = s;
1692 i &= 0xff;
1693 j &= 0xff;
1694 return (i << 8) | j;
1695 }
1696
1697
1698 int
ipf_p_ftp_eprt(softf,fin,ip,nat,ftp,dlen)1699 ipf_p_ftp_eprt(softf, fin, ip, nat, ftp, dlen)
1700 ipf_ftp_softc_t *softf;
1701 fr_info_t *fin;
1702 ip_t *ip;
1703 nat_t *nat;
1704 ftpinfo_t *ftp;
1705 int dlen;
1706 {
1707 ftpside_t *f;
1708
1709 /*
1710 * Check for client sending out EPRT message.
1711 */
1712 if (dlen < IPF_MINEPRTLEN) {
1713 DT1(epert_dlen, int, dlen);
1714 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
1715 printf("ipf_p_ftp_eprt:dlen(%d) < IPF_MINEPRTLEN\n",
1716 dlen);
1717 return 0;
1718 }
1719
1720 /*
1721 * Parse the EPRT command. Format is:
1722 * "EPRT |1|1.2.3.4|2000|" for IPv4 and
1723 * "EPRT |2|ef00::1:2|2000|" for IPv6
1724 */
1725 f = &ftp->ftp_side[0];
1726 if (f->ftps_rptr[5] != '|')
1727 return 0;
1728 if (f->ftps_rptr[5] == f->ftps_rptr[7]) {
1729 if (f->ftps_rptr[6] == '1' && nat->nat_v[0] == 4)
1730 return ipf_p_ftp_eprt4(softf, fin, ip, nat, ftp, dlen);
1731 #ifdef USE_INET6
1732 if (f->ftps_rptr[6] == '2' && nat->nat_v[0] == 6)
1733 return ipf_p_ftp_eprt6(softf, fin, ip, nat, ftp, dlen);
1734 #endif
1735 }
1736 return 0;
1737 }
1738
1739
1740 int
ipf_p_ftp_eprt4(softf,fin,ip,nat,ftp,dlen)1741 ipf_p_ftp_eprt4(softf, fin, ip, nat, ftp, dlen)
1742 ipf_ftp_softc_t *softf;
1743 fr_info_t *fin;
1744 ip_t *ip;
1745 nat_t *nat;
1746 ftpinfo_t *ftp;
1747 int dlen;
1748 {
1749 int a1, a2, a3, a4, port, olen, nlen, inc, off;
1750 char newbuf[IPF_FTPBUFSZ];
1751 char *s, c, delim;
1752 u_32_t addr, i;
1753 tcphdr_t *tcp;
1754 ftpside_t *f;
1755 mb_t *m;
1756
1757 m = fin->fin_m;
1758 tcp = (tcphdr_t *)fin->fin_dp;
1759 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
1760 f = &ftp->ftp_side[0];
1761 delim = f->ftps_rptr[5];
1762 s = f->ftps_rptr + 8;
1763
1764 /*
1765 * get the IP address.
1766 */
1767 i = 0;
1768 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1769 i *= 10;
1770 i += c - '0';
1771 }
1772 if (i > 255)
1773 return 0;
1774 if (c != '.')
1775 return 0;
1776 addr = (i << 24);
1777
1778 i = 0;
1779 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1780 i *= 10;
1781 i += c - '0';
1782 }
1783 if (i > 255)
1784 return 0;
1785 if (c != '.')
1786 return 0;
1787 addr |= (addr << 16);
1788
1789 i = 0;
1790 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1791 i *= 10;
1792 i += c - '0';
1793 }
1794 if (i > 255)
1795 return 0;
1796 if (c != '.')
1797 return 0;
1798 addr |= (addr << 8);
1799
1800 i = 0;
1801 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1802 i *= 10;
1803 i += c - '0';
1804 }
1805 if (i > 255)
1806 return 0;
1807 if (c != delim)
1808 return 0;
1809 addr |= addr;
1810
1811 /*
1812 * Get the port number
1813 */
1814 i = 0;
1815 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1816 i *= 10;
1817 i += c - '0';
1818 }
1819 if (i > 65535)
1820 return 0;
1821 if (c != delim)
1822 return 0;
1823 port = i;
1824
1825 /*
1826 * Check for CR-LF at the end of the command string.
1827 */
1828 if ((*s != '\r') || (*(s + 1) != '\n')) {
1829 DT(eprt4_no_crlf);
1830 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
1831 printf("ipf_p_ftp_eprt4:missing %s\n", "cr-lf");
1832 return 0;
1833 }
1834 s += 2;
1835
1836 /*
1837 * Calculate new address parts for PORT command
1838 */
1839 if (nat->nat_dir == NAT_INBOUND)
1840 a1 = ntohl(nat->nat_odstaddr);
1841 else
1842 a1 = ntohl(ip->ip_src.s_addr);
1843 a2 = (a1 >> 16) & 0xff;
1844 a3 = (a1 >> 8) & 0xff;
1845 a4 = a1 & 0xff;
1846 a1 >>= 24;
1847 olen = s - f->ftps_rptr;
1848 /* DO NOT change this to snprintf! */
1849 /*
1850 * While we could force the use of | as a delimiter here, it makes
1851 * sense to preserve whatever character is being used by the systems
1852 * involved in the communication.
1853 */
1854 #if defined(SNPRINTF) && defined(_KERNEL)
1855 SNPRINTF(newbuf, sizeof(newbuf), "%s %c1%c%u.%u.%u.%u%c%u%c\r\n",
1856 "EPRT", delim, delim, a1, a2, a3, a4, delim, port, delim);
1857 #else
1858 (void) sprintf(newbuf, "%s %c1%c%u.%u.%u.%u%c%u%c\r\n",
1859 "EPRT", delim, delim, a1, a2, a3, a4, delim, port,
1860 delim);
1861 #endif
1862
1863 nlen = strlen(newbuf);
1864 inc = nlen - olen;
1865 if ((inc + fin->fin_plen) > 65535) {
1866 DT2(eprt4_len, int, inc, int, fin->fin_plen);
1867 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
1868 printf("ipf_p_ftp_eprt4:inc(%d) + ip->ip_len > 65535\n",
1869 inc);
1870 return 0;
1871 }
1872
1873 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
1874 #if !defined(_KERNEL)
1875 M_ADJ(m, inc);
1876 #else
1877 if (inc < 0)
1878 M_ADJ(m, inc);
1879 #endif
1880 /* the mbuf chain will be extended if necessary by m_copyback() */
1881 COPYBACK(m, off, nlen, newbuf);
1882 fin->fin_flx |= FI_DOCKSUM;
1883
1884 if (inc != 0) {
1885 fin->fin_plen += inc;
1886 ip->ip_len = htons(fin->fin_plen);
1887 fin->fin_dlen += inc;
1888 }
1889
1890 f->ftps_cmd = FTPXY_C_EPRT;
1891 return ipf_p_ftp_addport(softf, fin, ip, nat, ftp, dlen, port, inc);
1892 }
1893
1894
1895 int
ipf_p_ftp_epsv(softf,fin,ip,nat,ftp,dlen)1896 ipf_p_ftp_epsv(softf, fin, ip, nat, ftp, dlen)
1897 ipf_ftp_softc_t *softf;
1898 fr_info_t *fin;
1899 ip_t *ip;
1900 nat_t *nat;
1901 ftpinfo_t *ftp;
1902 int dlen;
1903 {
1904 char newbuf[IPF_FTPBUFSZ];
1905 u_short ap = 0;
1906 ftpside_t *f;
1907 char *s;
1908
1909 if ((softf->ipf_p_ftp_forcepasv != 0) &&
1910 (ftp->ftp_side[0].ftps_cmd != FTPXY_C_EPSV)) {
1911 DT1(epsv_cmd, int, ftp->ftp_side[0].ftps_cmd);
1912 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
1913 printf("ipf_p_ftp_epsv:ftps_cmd(%d) != FTPXY_C_EPSV\n",
1914 ftp->ftp_side[0].ftps_cmd);
1915 return 0;
1916 }
1917 f = &ftp->ftp_side[1];
1918
1919 #define EPSV_REPLEN 33
1920 /*
1921 * Check for EPSV reply message.
1922 */
1923 if (dlen < IPF_MIN229LEN) {
1924 return (0);
1925 } else if (strncmp(f->ftps_rptr,
1926 "229 Entering Extended Passive Mode", EPSV_REPLEN)) {
1927 return (0);
1928 }
1929
1930 /*
1931 * Skip the EPSV command + space
1932 */
1933 s = f->ftps_rptr + 33;
1934 while (*s && !ISDIGIT(*s))
1935 s++;
1936
1937 /*
1938 * As per RFC 2428, there are no addres components in the EPSV
1939 * response. So we'll go straight to getting the port.
1940 */
1941 while (*s && ISDIGIT(*s)) {
1942 ap *= 10;
1943 ap += *s++ - '0';
1944 }
1945
1946 if (*s == '|')
1947 s++;
1948 if (*s == ')')
1949 s++;
1950 if (*s == '\n')
1951 s--;
1952 /*
1953 * check for CR-LF at the end.
1954 */
1955 if ((*s != '\r') || (*(s + 1) != '\n')) {
1956 return 0;
1957 }
1958 s += 2;
1959
1960 #if defined(SNPRINTF) && defined(_KERNEL)
1961 SNPRINTF(newbuf, sizeof(newbuf), "%s (|||%u|)\r\n",
1962 "229 Entering Extended Passive Mode", ap);
1963 #else
1964 (void) sprintf(newbuf, "%s (|||%u|)\r\n",
1965 "229 Entering Extended Passive Mode", ap);
1966 #endif
1967
1968 return ipf_p_ftp_pasvreply(softf, fin, ip, nat, ftp, (u_int)ap,
1969 newbuf, s);
1970 }
1971
1972 #ifdef USE_INET6
1973 int
ipf_p_ftp_eprt6(softf,fin,ip,nat,ftp,dlen)1974 ipf_p_ftp_eprt6(softf, fin, ip, nat, ftp, dlen)
1975 ipf_ftp_softc_t *softf;
1976 fr_info_t *fin;
1977 ip_t *ip;
1978 nat_t *nat;
1979 ftpinfo_t *ftp;
1980 int dlen;
1981 {
1982 int port, olen, nlen, inc, off, left, i;
1983 char newbuf[IPF_FTPBUFSZ];
1984 char *s, c;
1985 i6addr_t addr, *a6;
1986 tcphdr_t *tcp;
1987 ip6_t *ip6;
1988 char delim;
1989 u_short whole;
1990 u_short part;
1991 ftpside_t *f;
1992 u_short *t;
1993 int fwd;
1994 mb_t *m;
1995 u_32_t a;
1996
1997 m = fin->fin_m;
1998 ip6 = (ip6_t *)ip;
1999 f = &ftp->ftp_side[0];
2000 s = f->ftps_rptr + 8;
2001 f = &ftp->ftp_side[0];
2002 delim = f->ftps_rptr[5];
2003 tcp = (tcphdr_t *)fin->fin_dp;
2004 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
2005
2006 addr.i6[0] = 0;
2007 addr.i6[1] = 0;
2008 addr.i6[2] = 0;
2009 addr.i6[3] = 0;
2010 /*
2011 * Parse an IPv6 address.
2012 * Go forward until either :: or | is found. If :: is found,
2013 * reverse direction. Direction change is performed to ease
2014 * parsing an unknown number of 0s in the middle.
2015 */
2016 whole = 0;
2017 t = (u_short *)&addr;
2018 fwd = 1;
2019 for (part = 0; (c = *s) != '\0'; ) {
2020 if (c == delim) {
2021 *t = htons((u_short)whole);
2022 break;
2023 }
2024 if (c == ':') {
2025 *t = part;
2026 if (fwd) {
2027 *t = htons((u_short)whole);
2028 t++;
2029 } else {
2030 *t = htons((u_short)(whole >> 16));
2031 t--;
2032 }
2033 whole = 0;
2034 if (fwd == 1 && s[1] == ':') {
2035 while (*s && *s != '|')
2036 s++;
2037 if ((c = *s) != delim)
2038 break;
2039 t = (u_short *)&addr.i6[3];
2040 t++;
2041 fwd = 0;
2042 } else if (fwd == 0 && s[-1] == ':') {
2043 break;
2044 }
2045 } else {
2046 if (c >= '0' && c <= '9') {
2047 c -= '0';
2048 } else if (c >= 'a' && c <= 'f') {
2049 c -= 'a' + 10;
2050 } else if (c >= 'A' && c <= 'F') {
2051 c -= 'A' + 10;
2052 }
2053 if (fwd) {
2054 whole <<= 8;
2055 whole |= c;
2056 } else {
2057 whole >>= 8;
2058 whole |= ((u_32_t)c) << 24;
2059 }
2060 }
2061 if (fwd)
2062 s++;
2063 else
2064 s--;
2065 }
2066 if (c != ':' && c != delim)
2067 return 0;
2068
2069 while (*s != '|')
2070 s++;
2071 s++;
2072
2073 /*
2074 * Get the port number
2075 */
2076 i = 0;
2077 while (((c = *s++) != '\0') && ISDIGIT(c)) {
2078 i *= 10;
2079 i += c - '0';
2080 }
2081 if (i > 65535)
2082 return 0;
2083 if (c != delim)
2084 return 0;
2085 port = (u_short)(i & 0xffff);
2086
2087 /*
2088 * Check for CR-LF at the end of the command string.
2089 */
2090 if ((*s != '\r') || (*(s + 1) != '\n')) {
2091 DT(eprt6_no_crlf);
2092 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
2093 printf("ipf_p_ftp_eprt6:missing %s\n", "cr-lf");
2094 return 0;
2095 }
2096 s += 2;
2097
2098 /*
2099 * Calculate new address parts for PORT command
2100 */
2101 a6 = (i6addr_t *)&ip6->ip6_src;
2102 olen = s - f->ftps_rptr;
2103 /* DO NOT change this to snprintf! */
2104 /*
2105 * While we could force the use of | as a delimiter here, it makes
2106 * sense to preserve whatever character is being used by the systems
2107 * involved in the communication.
2108 */
2109 s = newbuf;
2110 left = sizeof(newbuf);
2111 #if defined(SNPRINTF) && defined(_KERNEL)
2112 SNPRINTF(newbuf, left, "EPRT %c2%c", delim, delim);
2113 left -= strlen(s) + 1;
2114 s += strlen(s);
2115 a = ntohl(a6->i6[0]);
2116 SNPRINTF(s, left, "%x:%x:", a >> 16, a & 0xffff);
2117 left -= strlen(s);
2118 s += strlen(s);
2119 a = ntohl(a6->i6[1]);
2120 SNPRINTF(s, left, "%x:%x:", a >> 16, a & 0xffff);
2121 left -= strlen(s);
2122 s += strlen(s);
2123 a = ntohl(a6->i6[2]);
2124 SNPRINTF(s, left, "%x:%x:", a >> 16, a & 0xffff);
2125 left -= strlen(s);
2126 s += strlen(s);
2127 a = ntohl(a6->i6[3]);
2128 SNPRINTF(s, left, "%x:%x", a >> 16, a & 0xffff);
2129 left -= strlen(s);
2130 s += strlen(s);
2131 SNPRINTF(s, left, "|%d|\r\n", port);
2132 #else
2133 (void) sprintf(s, "EPRT %c2%c", delim, delim);
2134 s += strlen(s);
2135 a = ntohl(a6->i6[0]);
2136 sprintf(s, "%x:%x:", a >> 16, a & 0xffff);
2137 s += strlen(s);
2138 a = ntohl(a6->i6[1]);
2139 sprintf(s, "%x:%x:", a >> 16, a & 0xffff);
2140 left -= strlen(s);
2141 s += strlen(s);
2142 a = ntohl(a6->i6[2]);
2143 sprintf(s, "%x:%x:", a >> 16, a & 0xffff);
2144 left -= strlen(s);
2145 s += strlen(s);
2146 a = ntohl(a6->i6[3]);
2147 sprintf(s, "%x:%x", a >> 16, a & 0xffff);
2148 left -= strlen(s);
2149 s += strlen(s);
2150 sprintf(s, "|%d|\r\n", port);
2151 #endif
2152 nlen = strlen(newbuf);
2153 inc = nlen - olen;
2154 if ((inc + fin->fin_plen) > 65535) {
2155 DT2(eprt6_len, int, inc, int, fin->fin_plen);
2156 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
2157 printf("ipf_p_ftp_eprt6:inc(%d) + ip->ip_len > 65535\n",
2158 inc);
2159 return 0;
2160 }
2161
2162 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
2163 #if !defined(_KERNEL)
2164 M_ADJ(m, inc);
2165 #else
2166 if (inc < 0)
2167 M_ADJ(m, inc);
2168 #endif
2169 /* the mbuf chain will be extended if necessary by m_copyback() */
2170 COPYBACK(m, off, nlen, newbuf);
2171 fin->fin_flx |= FI_DOCKSUM;
2172
2173 if (inc != 0) {
2174 fin->fin_plen += inc;
2175 ip6->ip6_plen = htons(fin->fin_plen - fin->fin_hlen);
2176 fin->fin_dlen += inc;
2177 }
2178
2179 f->ftps_cmd = FTPXY_C_EPRT;
2180 return ipf_p_ftp_addport(softf, fin, ip, nat, ftp, dlen, port, inc);
2181 }
2182 #endif
2183