1
2 /*
3 * Copyright (C) 2012 by Darren Reed.
4 *
5 * See the IPFILTER.LICENCE file for details on licencing.
6 *
7 * Simple FTP transparent proxy for in-kernel use. For use with the NAT
8 * code.
9 * Id: ip_ftp_pxy.c,v 2.88.2.19 2006/04/01 10:14:53 darrenr Exp $
10 */
11
12 #define IPF_FTP_PROXY
13
14 #define IPF_MINPORTLEN 18
15 #define IPF_MINEPRTLEN 20
16 #define IPF_MAXPORTLEN 30
17 #define IPF_MIN227LEN 39
18 #define IPF_MAX227LEN 51
19 #define IPF_MIN229LEN 47
20 #define IPF_MAX229LEN 51
21
22 #define FTPXY_GO 0
23 #define FTPXY_INIT 1
24 #define FTPXY_USER_1 2
25 #define FTPXY_USOK_1 3
26 #define FTPXY_PASS_1 4
27 #define FTPXY_PAOK_1 5
28 #define FTPXY_AUTH_1 6
29 #define FTPXY_AUOK_1 7
30 #define FTPXY_ADAT_1 8
31 #define FTPXY_ADOK_1 9
32 #define FTPXY_ACCT_1 10
33 #define FTPXY_ACOK_1 11
34 #define FTPXY_USER_2 12
35 #define FTPXY_USOK_2 13
36 #define FTPXY_PASS_2 14
37 #define FTPXY_PAOK_2 15
38
39 #define FTPXY_JUNK_OK 0
40 #define FTPXY_JUNK_BAD 1 /* Ignore all commands for this connection */
41 #define FTPXY_JUNK_EOL 2 /* consume the rest of this line only */
42 #define FTPXY_JUNK_CONT 3 /* Saerching for next numeric */
43
44 /*
45 * Values for FTP commands. Numerics cover 0-999
46 */
47 #define FTPXY_C_PASV 1000
48 #define FTPXY_C_PORT 1001
49 #define FTPXY_C_EPSV 1002
50 #define FTPXY_C_EPRT 1003
51
52
53 typedef struct ipf_ftp_softc_s {
54 int ipf_p_ftp_pasvonly;
55 /* Do not require logins before transfers */
56 int ipf_p_ftp_insecure;
57 int ipf_p_ftp_pasvrdr;
58 /* PASV must be last command prior to 227 */
59 int ipf_p_ftp_forcepasv;
60 int ipf_p_ftp_debug;
61 int ipf_p_ftp_single_xfer;
62 void *ipf_p_ftp_tune;
63 } ipf_ftp_softc_t;
64
65
66 void ipf_p_ftp_main_load(void);
67 void ipf_p_ftp_main_unload(void);
68 void *ipf_p_ftp_soft_create(ipf_main_softc_t *);
69 void ipf_p_ftp_soft_destroy(ipf_main_softc_t *, void *);
70
71 int ipf_p_ftp_client(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
72 ftpinfo_t *, int);
73 int ipf_p_ftp_complete(char *, size_t);
74 int ipf_p_ftp_in(void *, fr_info_t *, ap_session_t *, nat_t *);
75 int ipf_p_ftp_new(void *, fr_info_t *, ap_session_t *, nat_t *);
76 void ipf_p_ftp_del(ipf_main_softc_t *, ap_session_t *);
77 int ipf_p_ftp_out(void *, fr_info_t *, ap_session_t *, nat_t *);
78 int ipf_p_ftp_pasv(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
79 ftpinfo_t *, int);
80 int ipf_p_ftp_epsv(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
81 ftpinfo_t *, int);
82 int ipf_p_ftp_port(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
83 ftpinfo_t *, int);
84 int ipf_p_ftp_process(ipf_ftp_softc_t *, fr_info_t *, nat_t *,
85 ftpinfo_t *, int);
86 int ipf_p_ftp_server(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
87 ftpinfo_t *, int);
88 int ipf_p_ftp_valid(ipf_ftp_softc_t *, ftpinfo_t *, int, char *, size_t);
89 int ipf_p_ftp_server_valid(ipf_ftp_softc_t *, ftpside_t *, char *,
90 size_t);
91 int ipf_p_ftp_client_valid(ipf_ftp_softc_t *, ftpside_t *, char *,
92 size_t);
93 u_short ipf_p_ftp_atoi(char **);
94 int ipf_p_ftp_pasvreply(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
95 ftpinfo_t *, u_int, char *, char *);
96 int ipf_p_ftp_eprt(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
97 ftpinfo_t *, int);
98 int ipf_p_ftp_eprt4(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
99 ftpinfo_t *, int);
100 int ipf_p_ftp_eprt6(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
101 ftpinfo_t *, int);
102 int ipf_p_ftp_addport(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *,
103 ftpinfo_t *, int, int, int);
104 void ipf_p_ftp_setpending(ipf_main_softc_t *, ftpinfo_t *);
105
106 /*
107 * Debug levels
108 */
109 #define DEBUG_SECURITY 0x01
110 #define DEBUG_ERROR 0x02
111 #define DEBUG_INFO 0x04
112 #define DEBUG_PARSE_ERR 0x08
113 #define DEBUG_PARSE_INFO 0x10
114 #define DEBUG_PARSE 0x20
115
116 static int ipf_p_ftp_proxy_init = 0;
117 static frentry_t ftppxyfr;
118 static ipftuneable_t ipf_ftp_tuneables[] = {
119 { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_debug) },
120 "ftp_debug", 0, 0x7f,
121 stsizeof(ipf_ftp_softc_t, ipf_p_ftp_debug),
122 0, NULL, NULL },
123 { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_pasvonly) },
124 "ftp_pasvonly", 0, 1,
125 stsizeof(ipf_ftp_softc_t, ipf_p_ftp_pasvonly),
126 0, NULL, NULL },
127 { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_insecure) },
128 "ftp_insecure", 0, 1,
129 stsizeof(ipf_ftp_softc_t, ipf_p_ftp_insecure),
130 0, NULL, NULL },
131 { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_pasvrdr) },
132 "ftp_pasvrdr", 0, 1,
133 stsizeof(ipf_ftp_softc_t, ipf_p_ftp_pasvrdr),
134 0, NULL, NULL },
135 { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_forcepasv) },
136 "ftp_forcepasv", 0, 1,
137 stsizeof(ipf_ftp_softc_t, ipf_p_ftp_forcepasv),
138 0, NULL, NULL },
139 { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_single_xfer) },
140 "ftp_single_xfer", 0, 1,
141 stsizeof(ipf_ftp_softc_t, ipf_p_ftp_single_xfer),
142 0, NULL, NULL },
143 { { NULL }, NULL, 0, 0, 0, 0, NULL, NULL }
144 };
145
146
147 void
ipf_p_ftp_main_load(void)148 ipf_p_ftp_main_load(void)
149 {
150 bzero((char *)&ftppxyfr, sizeof(ftppxyfr));
151 ftppxyfr.fr_ref = 1;
152 ftppxyfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
153
154 MUTEX_INIT(&ftppxyfr.fr_lock, "FTP Proxy Mutex");
155 ipf_p_ftp_proxy_init = 1;
156 }
157
158
159 void
ipf_p_ftp_main_unload(void)160 ipf_p_ftp_main_unload(void)
161 {
162
163 if (ipf_p_ftp_proxy_init == 1) {
164 MUTEX_DESTROY(&ftppxyfr.fr_lock);
165 ipf_p_ftp_proxy_init = 0;
166 }
167 }
168
169
170 /*
171 * Initialize local structures.
172 */
173 void *
ipf_p_ftp_soft_create(ipf_main_softc_t * softc)174 ipf_p_ftp_soft_create(ipf_main_softc_t *softc)
175 {
176 ipf_ftp_softc_t *softf;
177
178 KMALLOC(softf, ipf_ftp_softc_t *);
179 if (softf == NULL)
180 return (NULL);
181
182 bzero((char *)softf, sizeof(*softf));
183 #if defined(_KERNEL)
184 softf->ipf_p_ftp_debug = 0;
185 #else
186 softf->ipf_p_ftp_debug = DEBUG_PARSE_ERR;
187 #endif
188 softf->ipf_p_ftp_forcepasv = 1;
189
190 softf->ipf_p_ftp_tune = ipf_tune_array_copy(softf,
191 sizeof(ipf_ftp_tuneables),
192 ipf_ftp_tuneables);
193 if (softf->ipf_p_ftp_tune == NULL) {
194 ipf_p_ftp_soft_destroy(softc, softf);
195 return (NULL);
196 }
197 if (ipf_tune_array_link(softc, softf->ipf_p_ftp_tune) == -1) {
198 ipf_p_ftp_soft_destroy(softc, softf);
199 return (NULL);
200 }
201
202 return (softf);
203 }
204
205
206 void
ipf_p_ftp_soft_destroy(ipf_main_softc_t * softc,void * arg)207 ipf_p_ftp_soft_destroy(ipf_main_softc_t *softc, void *arg)
208 {
209 ipf_ftp_softc_t *softf = arg;
210
211 if (softf->ipf_p_ftp_tune != NULL) {
212 ipf_tune_array_unlink(softc, softf->ipf_p_ftp_tune);
213 KFREES(softf->ipf_p_ftp_tune, sizeof(ipf_ftp_tuneables));
214 softf->ipf_p_ftp_tune = NULL;
215 }
216
217 KFREE(softf);
218 }
219
220
221 int
ipf_p_ftp_new(void * arg,fr_info_t * fin,ap_session_t * aps,nat_t * nat __unused)222 ipf_p_ftp_new(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat __unused)
223 {
224 ftpinfo_t *ftp;
225 ftpside_t *f;
226
227 KMALLOC(ftp, ftpinfo_t *);
228 if (ftp == NULL)
229 return (-1);
230
231 aps->aps_data = ftp;
232 aps->aps_psiz = sizeof(ftpinfo_t);
233 aps->aps_sport = htons(fin->fin_sport);
234 aps->aps_dport = htons(fin->fin_dport);
235
236 bzero((char *)ftp, sizeof(*ftp));
237 f = &ftp->ftp_side[0];
238 f->ftps_rptr = f->ftps_buf;
239 f->ftps_wptr = f->ftps_buf;
240 f = &ftp->ftp_side[1];
241 f->ftps_rptr = f->ftps_buf;
242 f->ftps_wptr = f->ftps_buf;
243 ftp->ftp_passok = FTPXY_INIT;
244 ftp->ftp_incok = 0;
245 return (0);
246 }
247
248
249 void
ipf_p_ftp_setpending(ipf_main_softc_t * softc,ftpinfo_t * ftp)250 ipf_p_ftp_setpending(ipf_main_softc_t *softc, ftpinfo_t *ftp)
251 {
252 if (ftp->ftp_pendnat != NULL)
253 ipf_nat_setpending(softc, ftp->ftp_pendnat);
254
255 if (ftp->ftp_pendstate != NULL) {
256 READ_ENTER(&softc->ipf_state);
257 ipf_state_setpending(softc, ftp->ftp_pendstate);
258 RWLOCK_EXIT(&softc->ipf_state);
259 }
260 }
261
262
263 void
ipf_p_ftp_del(ipf_main_softc_t * softc,ap_session_t * aps)264 ipf_p_ftp_del(ipf_main_softc_t *softc, ap_session_t *aps)
265 {
266 ftpinfo_t *ftp;
267
268 ftp = aps->aps_data;
269 if (ftp != NULL)
270 ipf_p_ftp_setpending(softc, ftp);
271 }
272
273
274 int
ipf_p_ftp_port(ipf_ftp_softc_t * softf,fr_info_t * fin,ip_t * ip,nat_t * nat,ftpinfo_t * ftp,int dlen)275 ipf_p_ftp_port(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat,
276 ftpinfo_t *ftp, int dlen)
277 {
278 char newbuf[IPF_FTPBUFSZ], *s;
279 u_int a1, a2, a3, a4;
280 u_short a5, a6, sp;
281 size_t nlen, olen;
282 tcphdr_t *tcp;
283 int inc, off;
284 ftpside_t *f;
285 mb_t *m;
286
287 m = fin->fin_m;
288 f = &ftp->ftp_side[0];
289 tcp = (tcphdr_t *)fin->fin_dp;
290 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
291
292 /*
293 * Check for client sending out PORT message.
294 */
295 if (dlen < IPF_MINPORTLEN) {
296 DT3(ftp_PORT_error_dlen, nat_t *, nat, ftpside_t *, f,
297 u_int, dlen);
298 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
299 printf("ipf_p_ftp_port:dlen(%d) < IPF_MINPORTLEN\n",
300 dlen);
301 return (0);
302 }
303 /*
304 * Skip the PORT command + space
305 */
306 s = f->ftps_rptr + 5;
307 /*
308 * Pick out the address components, two at a time.
309 */
310 a1 = ipf_p_ftp_atoi(&s);
311 if (s == NULL) {
312 DT2(ftp_PORT_error_atoi_1, nat_t *, nat, ftpside_t *, f);
313 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
314 printf("ipf_p_ftp_port:ipf_p_ftp_atoi(%d) failed\n", 1);
315 return (0);
316 }
317 a2 = ipf_p_ftp_atoi(&s);
318 if (s == NULL) {
319 DT2(ftp_PORT_error_atoi_2, nat_t *, nat, ftpside_t *, f);
320 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
321 printf("ipf_p_ftp_port:ipf_p_ftp_atoi(%d) failed\n", 2);
322 return (0);
323 }
324
325 /*
326 * Check that IP address in the PORT/PASV reply is the same as the
327 * sender of the command - prevents using PORT for port scanning.
328 */
329 a1 <<= 16;
330 a1 |= a2;
331 if (((nat->nat_dir == NAT_OUTBOUND) &&
332 (a1 != ntohl(nat->nat_osrcaddr))) ||
333 ((nat->nat_dir == NAT_INBOUND) &&
334 (a1 != ntohl(nat->nat_nsrcaddr)))) {
335 DT3(ftp_PORT_error_address, nat_t *, nat, ftpside_t *, f,
336 u_int, a1);
337 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
338 printf("ipf_p_ftp_port:%s != nat->nat_inip\n", "a1");
339 return (APR_ERR(1));
340 }
341
342 a5 = ipf_p_ftp_atoi(&s);
343 if (s == NULL) {
344 DT2(ftp_PORT_error_atoi_3, nat_t *, nat, ftpside_t *, f);
345 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
346 printf("ipf_p_ftp_port:ipf_p_ftp_atoi(%d) failed\n", 3);
347 return (0);
348 }
349 if (*s == ')')
350 s++;
351
352 /*
353 * check for CR-LF at the end.
354 */
355 if (*s == '\n')
356 s--;
357 if ((*s != '\r') || (*(s + 1) != '\n')) {
358 DT2(ftp_PORT_error_no_crlf, nat_t *, nat, ftpside_t *, f);
359 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
360 printf("ipf_p_ftp_port:missing %s\n", "cr-lf");
361 return (0);
362 }
363 s += 2;
364 a6 = a5 & 0xff;
365
366 /*
367 * Calculate the source port. Verification of > 1024 is in
368 * ipf_p_ftp_addport.
369 */
370 a5 >>= 8;
371 a5 &= 0xff;
372 sp = a5 << 8 | a6;
373
374 /*
375 * Calculate new address parts for PORT command
376 */
377 if (nat->nat_dir == NAT_INBOUND)
378 a1 = ntohl(nat->nat_ndstaddr);
379 else
380 a1 = ntohl(ip->ip_src.s_addr);
381 a1 = ntohl(ip->ip_src.s_addr);
382 a2 = (a1 >> 16) & 0xff;
383 a3 = (a1 >> 8) & 0xff;
384 a4 = a1 & 0xff;
385 a1 >>= 24;
386 olen = s - f->ftps_rptr;
387 (void) snprintf(newbuf, sizeof(newbuf), "%s %u,%u,%u,%u,%u,%u\r\n",
388 "PORT", a1, a2, a3, a4, a5, a6);
389
390 nlen = strlen(newbuf);
391 inc = nlen - olen;
392 if ((inc + fin->fin_plen) > 65535) {
393 DT3(ftp_PORT_error_inc, nat_t *, nat, ftpside_t *, f,
394 int, inc);
395 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
396 printf("ipf_p_ftp_port:inc(%d) + ip->ip_len > 65535\n",
397 inc);
398 return (0);
399 }
400
401 #if !defined(_KERNEL)
402 M_ADJ(m, inc);
403 #else
404 /*
405 * m_adj takes care of pkthdr.len, if required and treats inc<0 to
406 * mean remove -len bytes from the end of the packet.
407 * The mbuf chain will be extended if necessary by m_copyback().
408 */
409 if (inc < 0)
410 M_ADJ(m, inc);
411 #endif /* !defined(_KERNEL) */
412 COPYBACK(m, off, nlen, newbuf);
413 fin->fin_flx |= FI_DOCKSUM;
414
415 if (inc != 0) {
416 fin->fin_plen += inc;
417 ip->ip_len = htons(fin->fin_plen);
418 fin->fin_dlen += inc;
419 }
420
421 f->ftps_cmd = FTPXY_C_PORT;
422 return (ipf_p_ftp_addport(softf, fin, ip, nat, ftp, dlen, sp, inc));
423 }
424
425
426 int
ipf_p_ftp_addport(ipf_ftp_softc_t * softf,fr_info_t * fin,ip_t * ip,nat_t * nat,ftpinfo_t * ftp,int dlen,int nport,int inc)427 ipf_p_ftp_addport(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat,
428 ftpinfo_t *ftp, int dlen, int nport, int inc)
429 {
430 tcphdr_t tcph, *tcp2 = &tcph;
431 ipf_main_softc_t *softc;
432 ipf_nat_softc_t *softn;
433 int direction;
434 fr_info_t fi;
435 ipnat_t *ipn;
436 nat_t *nat2;
437 u_short sp;
438 int flags;
439
440 softc = fin->fin_main_soft;
441 softn = softc->ipf_nat_soft;
442
443 if ((ftp->ftp_pendnat != NULL) || (ftp->ftp_pendstate != NULL)) {
444 if (softf->ipf_p_ftp_single_xfer != 0) {
445 DT2(ftp_PORT_error_add_active, nat_t *, nat,
446 ftpinfo_t *, ftp);
447 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
448 printf("ipf_p_ftp_addport:xfer active %p/%p\n",
449 ftp->ftp_pendnat, ftp->ftp_pendstate);
450 return (0);
451 }
452 ipf_p_ftp_setpending(softc, ftp);
453 }
454
455 /*
456 * Add skeleton NAT entry for connection which will come back the
457 * other way.
458 */
459 sp = nport;
460 /*
461 * Don't allow the PORT command to specify a port < 1024 due to
462 * security risks.
463 */
464 if (sp < 1024) {
465 DT3(ftp_PORT_error_port, nat_t *, nat, ftpinfo_t *, ftp,
466 u_int, sp);
467 if (softf->ipf_p_ftp_debug & DEBUG_SECURITY)
468 printf("ipf_p_ftp_addport:sp(%d) < 1024\n", sp);
469 return (0);
470 }
471 /*
472 * The server may not make the connection back from port 20, but
473 * it is the most likely so use it here to check for a conflicting
474 * mapping.
475 */
476 bcopy((char *)fin, (char *)&fi, sizeof(fi));
477 fi.fin_flx |= FI_IGNORE;
478 fi.fin_data[0] = sp;
479 fi.fin_data[1] = fin->fin_data[1] - 1;
480 fi.fin_src6 = nat->nat_ndst6;
481 fi.fin_dst6 = nat->nat_nsrc6;
482
483 #ifndef USE_INET6
484 if (nat->nat_v[0] == 6)
485 return (APR_INC(inc));
486 #endif
487
488 /*
489 * If an existing entry already exists, use it instead.
490 */
491 #ifdef USE_INET6
492 if (nat->nat_v[0] == 6) {
493 if (nat->nat_dir == NAT_OUTBOUND) {
494 nat2 = ipf_nat6_outlookup(&fi, IPN_TCP|NAT_SEARCH,
495 nat->nat_pr[1],
496 &nat->nat_osrc6.in6,
497 &nat->nat_odst6.in6);
498 } else {
499 nat2 = ipf_nat6_inlookup(&fi, IPN_TCP|NAT_SEARCH,
500 nat->nat_pr[0],
501 &nat->nat_odst6.in6,
502 &nat->nat_osrc6.in6);
503 }
504 } else
505 #endif
506 {
507 if (nat->nat_dir == NAT_OUTBOUND) {
508 nat2 = ipf_nat_outlookup(&fi, IPN_TCP|NAT_SEARCH,
509 nat->nat_pr[1],
510 nat->nat_osrcip,
511 nat->nat_odstip);
512 } else {
513 nat2 = ipf_nat_inlookup(&fi, IPN_TCP|NAT_SEARCH,
514 nat->nat_pr[0],
515 nat->nat_odstip,
516 nat->nat_osrcip);
517 }
518 }
519 if (nat2 != NULL)
520 return (APR_INC(inc));
521
522 /*
523 * An existing entry doesn't exist. Let's make one.
524 */
525 ipn = ipf_proxy_rule_rev(nat);
526 if (ipn == NULL)
527 return (APR_ERR(1));
528 ipn->in_use = 0;
529
530 fi.fin_fr = &ftppxyfr;
531 fi.fin_dp = (char *)tcp2;
532 fi.fin_dlen = sizeof(*tcp2);
533 fi.fin_plen = fi.fin_hlen + sizeof(*tcp2);
534 fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE;
535 fi.fin_data[1] = sp;
536 fi.fin_data[0] = 0;
537
538 bzero((char *)tcp2, sizeof(*tcp2));
539 tcp2->th_sport = 0;
540 tcp2->th_dport = htons(sp);
541
542 tcp2->th_win = htons(8192);
543 TCP_OFF_A(tcp2, 5);
544 tcp_set_flags(tcp2, TH_SYN);
545
546 if (nat->nat_dir == NAT_INBOUND) {
547 fi.fin_out = 1;
548 direction = NAT_OUTBOUND;
549 } else {
550 fi.fin_out = 0;
551 direction = NAT_INBOUND;
552 }
553 flags = SI_W_SPORT|NAT_SLAVE|IPN_TCP;
554
555 MUTEX_ENTER(&softn->ipf_nat_new);
556 #ifdef USE_INET6
557 if (nat->nat_v[0] == 6)
558 nat2 = ipf_nat6_add(&fi, ipn, &ftp->ftp_pendnat, flags,
559 direction);
560 else
561 #endif
562 nat2 = ipf_nat_add(&fi, ipn, &ftp->ftp_pendnat, flags,
563 direction);
564 MUTEX_EXIT(&softn->ipf_nat_new);
565
566 if (nat2 == NULL) {
567 KFREES(ipn, ipn->in_size);
568 return (APR_ERR(1));
569 }
570
571 (void) ipf_nat_proto(&fi, nat2, IPN_TCP);
572 MUTEX_ENTER(&nat2->nat_lock);
573 ipf_nat_update(&fi, nat2);
574 MUTEX_EXIT(&nat2->nat_lock);
575 fi.fin_ifp = NULL;
576 if (nat2->nat_dir == NAT_INBOUND)
577 fi.fin_dst6 = nat->nat_osrc6;
578 if (ipf_state_add(softc, &fi, (ipstate_t **)&ftp->ftp_pendstate,
579 SI_W_SPORT) != 0)
580 ipf_nat_setpending(softc, nat2);
581
582 return (APR_INC(inc));
583 }
584
585
586 int
ipf_p_ftp_client(ipf_ftp_softc_t * softf,fr_info_t * fin,ip_t * ip,nat_t * nat,ftpinfo_t * ftp,int dlen)587 ipf_p_ftp_client(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip,
588 nat_t *nat, ftpinfo_t *ftp, int dlen)
589 {
590 char *rptr, *wptr, cmd[6], c;
591 ftpside_t *f;
592 int inc, i;
593
594 inc = 0;
595 f = &ftp->ftp_side[0];
596 rptr = f->ftps_rptr;
597 wptr = f->ftps_wptr;
598
599 for (i = 0; (i < 5) && (i < dlen); i++) {
600 c = rptr[i];
601 if (ISALPHA(c)) {
602 cmd[i] = TOUPPER(c);
603 } else {
604 cmd[i] = c;
605 }
606 }
607 cmd[i] = '\0';
608
609 ftp->ftp_incok = 0;
610 DT2(ftp_client_command, char [], cmd, int, ftp->ftp_passok);
611 if (!strncmp(cmd, "USER ", 5) || !strncmp(cmd, "XAUT ", 5)) {
612 if (ftp->ftp_passok == FTPXY_ADOK_1 ||
613 ftp->ftp_passok == FTPXY_AUOK_1) {
614 ftp->ftp_passok = FTPXY_USER_2;
615 ftp->ftp_incok = 1;
616 } else {
617 ftp->ftp_passok = FTPXY_USER_1;
618 ftp->ftp_incok = 1;
619 }
620 } else if (!strncmp(cmd, "AUTH ", 5)) {
621 ftp->ftp_passok = FTPXY_AUTH_1;
622 ftp->ftp_incok = 1;
623 } else if (!strncmp(cmd, "PASS ", 5)) {
624 if (ftp->ftp_passok == FTPXY_USOK_1) {
625 ftp->ftp_passok = FTPXY_PASS_1;
626 ftp->ftp_incok = 1;
627 } else if (ftp->ftp_passok == FTPXY_USOK_2) {
628 ftp->ftp_passok = FTPXY_PASS_2;
629 ftp->ftp_incok = 1;
630 }
631 } else if ((ftp->ftp_passok == FTPXY_AUOK_1) &&
632 !strncmp(cmd, "ADAT ", 5)) {
633 ftp->ftp_passok = FTPXY_ADAT_1;
634 ftp->ftp_incok = 1;
635 } else if ((ftp->ftp_passok == FTPXY_PAOK_1 ||
636 ftp->ftp_passok == FTPXY_PAOK_2) &&
637 !strncmp(cmd, "ACCT ", 5)) {
638 ftp->ftp_passok = FTPXY_ACCT_1;
639 ftp->ftp_incok = 1;
640 } else if ((ftp->ftp_passok == FTPXY_GO) &&
641 !softf->ipf_p_ftp_pasvonly &&
642 !strncmp(cmd, "PORT ", 5)) {
643 inc = ipf_p_ftp_port(softf, fin, ip, nat, ftp, dlen);
644 } else if ((ftp->ftp_passok == FTPXY_GO) &&
645 !softf->ipf_p_ftp_pasvonly &&
646 !strncmp(cmd, "EPRT ", 5)) {
647 inc = ipf_p_ftp_eprt(softf, fin, ip, nat, ftp, dlen);
648 } else if (softf->ipf_p_ftp_insecure &&
649 !softf->ipf_p_ftp_pasvonly &&
650 !strncmp(cmd, "PORT ", 5)) {
651 inc = ipf_p_ftp_port(softf, fin, ip, nat, ftp, dlen);
652 }
653 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
654 printf("ipf_p_ftp_client: cmd[%s] passok %d incok %d inc %d\n",
655 cmd, ftp->ftp_passok, ftp->ftp_incok, inc);
656
657 DT2(ftp_client_passok, char *, cmd, int, ftp->ftp_passok);
658 while ((*rptr++ != '\n') && (rptr < wptr))
659 ;
660 f->ftps_rptr = rptr;
661 return (inc);
662 }
663
664
665 int
ipf_p_ftp_pasv(ipf_ftp_softc_t * softf,fr_info_t * fin,ip_t * ip,nat_t * nat,ftpinfo_t * ftp,int dlen)666 ipf_p_ftp_pasv(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat,
667 ftpinfo_t *ftp, int dlen)
668 {
669 u_int a1, a2, a3, a4, data_ip;
670 char newbuf[IPF_FTPBUFSZ];
671 const char *brackets[2];
672 u_short a5, a6;
673 ftpside_t *f;
674 char *s;
675
676 if ((softf->ipf_p_ftp_forcepasv != 0) &&
677 (ftp->ftp_side[0].ftps_cmd != FTPXY_C_PASV)) {
678 DT2(ftp_PASV_error_state, nat_t *, nat, ftpinfo_t *, ftp);
679 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
680 printf("ipf_p_ftp_pasv:ftps_cmd(%d) != FTPXY_C_PASV\n",
681 ftp->ftp_side[0].ftps_cmd);
682 return (0);
683 }
684
685 f = &ftp->ftp_side[1];
686
687 #define PASV_REPLEN 24
688 /*
689 * Check for PASV reply message.
690 */
691 if (dlen < IPF_MIN227LEN) {
692 DT3(ftp_PASV_error_short, nat_t *, nat, ftpinfo_t *, ftp,
693 int, dlen);
694 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
695 printf("ipf_p_ftp_pasv:dlen(%d) < IPF_MIN227LEN\n",
696 dlen);
697 return (0);
698 } else if (strncmp(f->ftps_rptr,
699 "227 Entering Passive Mod", PASV_REPLEN)) {
700 DT2(ftp_PASV_error_string, nat_t *, nat, ftpinfo_t *, ftp);
701 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
702 printf("ipf_p_ftp_pasv:%d reply wrong\n", 227);
703 return (0);
704 }
705
706 brackets[0] = "";
707 brackets[1] = "";
708 /*
709 * Skip the PASV reply + space
710 */
711 s = f->ftps_rptr + PASV_REPLEN;
712 while (*s && !ISDIGIT(*s)) {
713 if (*s == '(') {
714 brackets[0] = "(";
715 brackets[1] = ")";
716 }
717 s++;
718 }
719
720 /*
721 * Pick out the address components, two at a time.
722 */
723 a1 = ipf_p_ftp_atoi(&s);
724 if (s == NULL) {
725 DT2(ftp_PASV_error_atoi_1, nat_t *, nat, ftpside_t *, f);
726 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
727 printf("ipf_p_ftp_pasv:ipf_p_ftp_atoi(%d) failed\n", 1);
728 return (0);
729 }
730 a2 = ipf_p_ftp_atoi(&s);
731 if (s == NULL) {
732 DT2(ftp_PASV_error_atoi_2, nat_t *, nat, ftpside_t *, f);
733 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
734 printf("ipf_p_ftp_pasv:ipf_p_ftp_atoi(%d) failed\n", 2);
735 return (0);
736 }
737
738 /*
739 * check that IP address in the PASV reply is the same as the
740 * sender of the command - prevents using PASV for port scanning.
741 */
742 a1 <<= 16;
743 a1 |= a2;
744
745 if (((nat->nat_dir == NAT_INBOUND) &&
746 (a1 != ntohl(nat->nat_ndstaddr))) ||
747 ((nat->nat_dir == NAT_OUTBOUND) &&
748 (a1 != ntohl(nat->nat_odstaddr)))) {
749 DT3(ftp_PASV_error_address, nat_t *, nat, ftpside_t *, f,
750 u_int, a1);
751 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
752 printf("ipf_p_ftp_pasv:%s != nat->nat_oip\n", "a1");
753 return (0);
754 }
755
756 a5 = ipf_p_ftp_atoi(&s);
757 if (s == NULL) {
758 DT2(ftp_PASV_error_atoi_3, nat_t *, nat, ftpside_t *, f);
759 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
760 printf("ipf_p_ftp_pasv:ipf_p_ftp_atoi(%d) failed\n", 3);
761 return (0);
762 }
763
764 if (*s == ')')
765 s++;
766 if (*s == '.')
767 s++;
768 if (*s == '\n')
769 s--;
770 /*
771 * check for CR-LF at the end.
772 */
773 if ((*s != '\r') || (*(s + 1) != '\n')) {
774 DT(pasv_missing_crlf);
775 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
776 printf("ipf_p_ftp_pasv:missing %s", "cr-lf\n");
777 return (0);
778 }
779 s += 2;
780
781 a6 = a5 & 0xff;
782 a5 >>= 8;
783 /*
784 * Calculate new address parts for 227 reply
785 */
786 if (nat->nat_dir == NAT_INBOUND) {
787 data_ip = nat->nat_odstaddr;
788 a1 = ntohl(data_ip);
789 } else
790 data_ip = htonl(a1);
791
792 a2 = (a1 >> 16) & 0xff;
793 a3 = (a1 >> 8) & 0xff;
794 a4 = a1 & 0xff;
795 a1 >>= 24;
796
797 (void) snprintf(newbuf, sizeof(newbuf), "%s %s%u,%u,%u,%u,%u,%u%s\r\n",
798 "227 Entering Passive Mode", brackets[0], a1, a2, a3, a4,
799 a5, a6, brackets[1]);
800 return (ipf_p_ftp_pasvreply(softf, fin, ip, nat, ftp, (a5 << 8 | a6),
801 newbuf, s));
802 }
803
804 int
ipf_p_ftp_pasvreply(ipf_ftp_softc_t * softf,fr_info_t * fin,ip_t * ip,nat_t * nat,ftpinfo_t * ftp,u_int port,char * newmsg,char * s)805 ipf_p_ftp_pasvreply(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip,
806 nat_t *nat, ftpinfo_t *ftp, u_int port, char *newmsg, char *s)
807 {
808 int inc, off, nflags;
809 tcphdr_t *tcp, tcph, *tcp2;
810 ipf_main_softc_t *softc;
811 ipf_nat_softc_t *softn;
812 size_t nlen, olen;
813 #ifdef USE_INET6
814 ip6_t *ip6;
815 #endif
816 ipnat_t *ipn;
817 fr_info_t fi;
818 ftpside_t *f;
819 nat_t *nat2;
820 mb_t *m;
821
822 softc = fin->fin_main_soft;
823 softn = softc->ipf_nat_soft;
824
825 if ((ftp->ftp_pendnat != NULL) || (ftp->ftp_pendstate != NULL))
826 ipf_p_ftp_setpending(softc, ftp);
827
828 m = fin->fin_m;
829 tcp = (tcphdr_t *)fin->fin_dp;
830 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
831
832 tcp2 = &tcph;
833 inc = 0;
834
835 f = &ftp->ftp_side[1];
836 olen = s - f->ftps_rptr;
837 nlen = strlen(newmsg);
838 inc = nlen - olen;
839 if ((inc + fin->fin_plen) > 65535) {
840 DT3(ftp_PASV_error_inc, nat_t *, nat, ftpside_t *, f,
841 int, inc);
842 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
843 printf("ipf_p_ftp_pasv:inc(%d) + ip->ip_len > 65535\n",
844 inc);
845 return (0);
846 }
847
848 ipn = ipf_proxy_rule_fwd(nat);
849 if (ipn == NULL)
850 return (APR_ERR(1));
851 ipn->in_use = 0;
852
853 /*
854 * Add skeleton NAT entry for connection which will come back the
855 * other way.
856 */
857 bzero((char *)tcp2, sizeof(*tcp2));
858 bcopy((char *)fin, (char *)&fi, sizeof(fi));
859 fi.fin_flx |= FI_IGNORE;
860 fi.fin_data[0] = 0;
861 fi.fin_data[1] = port;
862 nflags = IPN_TCP|SI_W_SPORT;
863
864 fi.fin_fr = &ftppxyfr;
865 fi.fin_dp = (char *)tcp2;
866 fi.fin_out = 1 - fin->fin_out;
867 fi.fin_dlen = sizeof(*tcp2);
868 fi.fin_src6 = nat->nat_osrc6;
869 fi.fin_dst6 = nat->nat_odst6;
870 fi.fin_plen = fi.fin_hlen + sizeof(*tcp);
871 fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE;
872
873 TCP_OFF_A(tcp2, 5);
874 tcp_set_flags(tcp2, TH_SYN);
875 tcp2->th_win = htons(8192);
876 tcp2->th_dport = htons(port);
877
878 MUTEX_ENTER(&softn->ipf_nat_new);
879 #ifdef USE_INET6
880 if (nat->nat_v[0] == 6)
881 nat2 = ipf_nat6_add(&fi, ipn, &ftp->ftp_pendnat,
882 nflags, nat->nat_dir);
883 else
884 #endif
885 nat2 = ipf_nat_add(&fi, ipn, &ftp->ftp_pendnat,
886 nflags, nat->nat_dir);
887 MUTEX_EXIT(&softn->ipf_nat_new);
888
889 if (nat2 == NULL) {
890 KFREES(ipn, ipn->in_size);
891 return (APR_ERR(1));
892 }
893
894 (void) ipf_nat_proto(&fi, nat2, IPN_TCP);
895 MUTEX_ENTER(&nat2->nat_lock);
896 ipf_nat_update(&fi, nat2);
897 MUTEX_EXIT(&nat2->nat_lock);
898 fi.fin_ifp = NULL;
899 if (nat->nat_dir == NAT_INBOUND) {
900 #ifdef USE_INET6
901 if (nat->nat_v[0] == 6)
902 fi.fin_dst6 = nat->nat_ndst6;
903 else
904 #endif
905 fi.fin_daddr = nat->nat_ndstaddr;
906 }
907 if (ipf_state_add(softc, &fi, (ipstate_t **)&ftp->ftp_pendstate,
908 SI_W_SPORT) != 0)
909 ipf_nat_setpending(softc, nat2);
910
911 #if !defined(_KERNEL)
912 M_ADJ(m, inc);
913 #else
914 /*
915 * m_adj takes care of pkthdr.len, if required and treats inc<0 to
916 * mean remove -len bytes from the end of the packet.
917 * The mbuf chain will be extended if necessary by m_copyback().
918 */
919 if (inc < 0)
920 M_ADJ(m, inc);
921 #endif /* !defined(_KERNEL) */
922 COPYBACK(m, off, nlen, newmsg);
923 fin->fin_flx |= FI_DOCKSUM;
924
925 if (inc != 0) {
926 fin->fin_plen += inc;
927 fin->fin_dlen += inc;
928 #ifdef USE_INET6
929 if (nat->nat_v[0] == 6) {
930 ip6 = (ip6_t *)fin->fin_ip;
931 u_short len = ntohs(ip6->ip6_plen) + inc;
932 ip6->ip6_plen = htons(len);
933 } else
934 #endif
935 ip->ip_len = htons(fin->fin_plen);
936 }
937
938 return (APR_INC(inc));
939 }
940
941
942 int
ipf_p_ftp_server(ipf_ftp_softc_t * softf,fr_info_t * fin,ip_t * ip,nat_t * nat,ftpinfo_t * ftp,int dlen)943 ipf_p_ftp_server(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat,
944 ftpinfo_t *ftp, int dlen)
945 {
946 char *rptr, *wptr;
947 ftpside_t *f;
948 int inc;
949
950 inc = 0;
951 f = &ftp->ftp_side[1];
952 rptr = f->ftps_rptr;
953 wptr = f->ftps_wptr;
954
955 DT2(ftp_server_response, char *, rptr, int, ftp->ftp_passok);
956 if (*rptr == ' ')
957 goto server_cmd_ok;
958 if (!ISDIGIT(*rptr) || !ISDIGIT(*(rptr + 1)) || !ISDIGIT(*(rptr + 2)))
959 return (0);
960 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
961 printf("ipf_p_ftp_server_1: cmd[%4.4s] passok %d\n",
962 rptr, ftp->ftp_passok);
963 if (ftp->ftp_passok == FTPXY_GO) {
964 if (!strncmp(rptr, "227 ", 4))
965 inc = ipf_p_ftp_pasv(softf, fin, ip, nat, ftp, dlen);
966 else if (!strncmp(rptr, "229 ", 4))
967 inc = ipf_p_ftp_epsv(softf, fin, ip, nat, ftp, dlen);
968 else if (strncmp(rptr, "200", 3)) {
969 /*
970 * 200 is returned for a successful command.
971 */
972 ;
973 }
974 } else if (softf->ipf_p_ftp_insecure && !strncmp(rptr, "227 ", 4)) {
975 inc = ipf_p_ftp_pasv(softf, fin, ip, nat, ftp, dlen);
976 } else if (softf->ipf_p_ftp_insecure && !strncmp(rptr, "229 ", 4)) {
977 inc = ipf_p_ftp_epsv(softf, fin, ip, nat, ftp, dlen);
978 } else if (*rptr == '5' || *rptr == '4')
979 ftp->ftp_passok = FTPXY_INIT;
980 else if (ftp->ftp_incok) {
981 if (*rptr == '3') {
982 if (ftp->ftp_passok == FTPXY_ACCT_1)
983 ftp->ftp_passok = FTPXY_GO;
984 else
985 ftp->ftp_passok++;
986 } else if (*rptr == '2') {
987 switch (ftp->ftp_passok)
988 {
989 case FTPXY_USER_1 :
990 case FTPXY_USER_2 :
991 case FTPXY_PASS_1 :
992 case FTPXY_PASS_2 :
993 case FTPXY_ACCT_1 :
994 ftp->ftp_passok = FTPXY_GO;
995 break;
996 default :
997 ftp->ftp_passok += 3;
998 break;
999 }
1000 }
1001 }
1002 ftp->ftp_incok = 0;
1003 server_cmd_ok:
1004 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
1005 printf("ipf_p_ftp_server_2: cmd[%4.4s] passok %d\n",
1006 rptr, ftp->ftp_passok);
1007 DT3(ftp_server_passok, char *,rptr, int, ftp->ftp_incok,
1008 int, ftp->ftp_passok);
1009
1010 while ((*rptr++ != '\n') && (rptr < wptr))
1011 ;
1012 f->ftps_rptr = rptr;
1013 return (inc);
1014 }
1015
1016
1017 /*
1018 * 0 FTPXY_JUNK_OK
1019 * 1 FTPXY_JUNK_BAD
1020 * 2 FTPXY_JUNK_EOL
1021 * 3 FTPXY_JUNK_CONT
1022 *
1023 * Look to see if the buffer starts with something which we recognise as
1024 * being the correct syntax for the FTP protocol.
1025 */
1026 int
ipf_p_ftp_client_valid(ipf_ftp_softc_t * softf,ftpside_t * ftps,char * buf,size_t len)1027 ipf_p_ftp_client_valid(ipf_ftp_softc_t *softf, ftpside_t *ftps, char *buf,
1028 size_t len)
1029 {
1030 register char *s, c, pc;
1031 register size_t i = len;
1032 char cmd[5];
1033
1034 s = buf;
1035
1036 if (ftps->ftps_junk == FTPXY_JUNK_BAD)
1037 return (FTPXY_JUNK_BAD);
1038
1039 if (i < 5) {
1040 DT1(client_valid, int, i);
1041 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
1042 printf("ipf_p_ftp_client_valid:i(%d) < 5\n", (int)i);
1043 return (2);
1044 }
1045
1046 i--;
1047 c = *s++;
1048
1049 if (ISALPHA(c)) {
1050 cmd[0] = TOUPPER(c);
1051 c = *s++;
1052 i--;
1053 if (ISALPHA(c)) {
1054 cmd[1] = TOUPPER(c);
1055 c = *s++;
1056 i--;
1057 if (ISALPHA(c)) {
1058 cmd[2] = TOUPPER(c);
1059 c = *s++;
1060 i--;
1061 if (ISALPHA(c)) {
1062 cmd[3] = TOUPPER(c);
1063 c = *s++;
1064 i--;
1065 if ((c != ' ') && (c != '\r'))
1066 goto bad_client_command;
1067 } else if ((c != ' ') && (c != '\r'))
1068 goto bad_client_command;
1069 } else
1070 goto bad_client_command;
1071 } else
1072 goto bad_client_command;
1073 } else {
1074 bad_client_command:
1075 DT4(client_junk, int, len, int, i, int, c, char *, buf);
1076 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
1077 printf("%s:bad:junk %d len %d/%d c 0x%x buf [%*.*s]\n",
1078 "ipf_p_ftp_client_valid",
1079 ftps->ftps_junk, (int)len, (int)i, c,
1080 (int)len, (int)len, buf);
1081 return (FTPXY_JUNK_BAD);
1082 }
1083
1084 for (; i; i--) {
1085 pc = c;
1086 c = *s++;
1087 if ((pc == '\r') && (c == '\n')) {
1088 cmd[4] = '\0';
1089 if (!strcmp(cmd, "PASV")) {
1090 ftps->ftps_cmd = FTPXY_C_PASV;
1091 } else if (!strcmp(cmd, "EPSV")) {
1092 ftps->ftps_cmd = FTPXY_C_EPSV;
1093 } else {
1094 ftps->ftps_cmd = 0;
1095 }
1096 return (0);
1097 }
1098 }
1099 #if !defined(_KERNEL)
1100 printf("ipf_p_ftp_client_valid:junk after cmd[%*.*s]\n",
1101 (int)len, (int)len, buf);
1102 #endif
1103 return (FTPXY_JUNK_EOL);
1104 }
1105
1106
1107 int
ipf_p_ftp_server_valid(ipf_ftp_softc_t * softf,ftpside_t * ftps,char * buf,size_t len)1108 ipf_p_ftp_server_valid(ipf_ftp_softc_t *softf, ftpside_t *ftps, char *buf,
1109 size_t len)
1110 {
1111 register char *s, c, pc;
1112 register size_t i = len;
1113 int cmd;
1114
1115 s = buf;
1116 cmd = 0;
1117
1118 if (ftps->ftps_junk == FTPXY_JUNK_BAD)
1119 return (FTPXY_JUNK_BAD);
1120
1121 if (i < 5) {
1122 DT1(server_valid, int, i);
1123 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
1124 printf("ipf_p_ftp_servert_valid:i(%d) < 5\n", (int)i);
1125 return (2);
1126 }
1127
1128 c = *s++;
1129 i--;
1130 if (c == ' ') {
1131 cmd = -1;
1132 goto search_eol;
1133 }
1134
1135 if (ISDIGIT(c)) {
1136 cmd = (c - '0') * 100;
1137 c = *s++;
1138 i--;
1139 if (ISDIGIT(c)) {
1140 cmd += (c - '0') * 10;
1141 c = *s++;
1142 i--;
1143 if (ISDIGIT(c)) {
1144 cmd += (c - '0');
1145 c = *s++;
1146 i--;
1147 if ((c != '-') && (c != ' '))
1148 goto bad_server_command;
1149 if (c == '-')
1150 return (FTPXY_JUNK_CONT);
1151 } else
1152 goto bad_server_command;
1153 } else
1154 goto bad_server_command;
1155 } else {
1156 bad_server_command:
1157 DT4(server_junk, int len, buf, int, i, int, c, char *, buf);
1158 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_INFO)
1159 printf("%s:bad:junk %d len %d/%d c 0x%x buf [%*.*s]\n",
1160 "ipf_p_ftp_server_valid",
1161 ftps->ftps_junk, (int)len, (int)i,
1162 c, (int)len, (int)len, buf);
1163 if (ftps->ftps_junk == FTPXY_JUNK_CONT)
1164 return (FTPXY_JUNK_CONT);
1165 return (FTPXY_JUNK_BAD);
1166 }
1167 search_eol:
1168 for (; i; i--) {
1169 pc = c;
1170 c = *s++;
1171 if ((pc == '\r') && (c == '\n')) {
1172 if (cmd == -1) {
1173 if (ftps->ftps_junk == FTPXY_JUNK_CONT)
1174 return (FTPXY_JUNK_CONT);
1175 } else {
1176 ftps->ftps_cmd = cmd;
1177 }
1178 return (FTPXY_JUNK_OK);
1179 }
1180 }
1181
1182 DT2(junk_eol, int, len, char *, buf);
1183 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_INFO)
1184 printf("ipf_p_ftp_server_valid:junk after cmd[%*.*s]\n",
1185 (int)len, (int)len, buf);
1186 return (FTPXY_JUNK_EOL);
1187 }
1188
1189
1190 int
ipf_p_ftp_valid(ipf_ftp_softc_t * softf,ftpinfo_t * ftp,int side,char * buf,size_t len)1191 ipf_p_ftp_valid(ipf_ftp_softc_t *softf, ftpinfo_t *ftp, int side, char *buf,
1192 size_t len)
1193 {
1194 ftpside_t *ftps;
1195
1196 ftps = &ftp->ftp_side[side];
1197
1198 if (side == 0)
1199 return (ipf_p_ftp_client_valid(softf, ftps, buf, len));
1200 else
1201 return (ipf_p_ftp_server_valid(softf, ftps, buf, len));
1202 }
1203
1204
1205 /*
1206 * For map rules, the following applies:
1207 * rv == 0 for outbound processing,
1208 * rv == 1 for inbound processing.
1209 * For rdr rules, the following applies:
1210 * rv == 0 for inbound processing,
1211 * rv == 1 for outbound processing.
1212 */
1213 int
ipf_p_ftp_process(ipf_ftp_softc_t * softf,fr_info_t * fin,nat_t * nat,ftpinfo_t * ftp,int rv)1214 ipf_p_ftp_process(ipf_ftp_softc_t *softf, fr_info_t *fin, nat_t *nat,
1215 ftpinfo_t *ftp, int rv)
1216 {
1217 int mlen, len, off, inc, i, sel, sel2, ok, ackoff, seqoff, retry;
1218 char *rptr, *wptr, *s;
1219 u_32_t thseq, thack;
1220 ap_session_t *aps;
1221 ftpside_t *f, *t;
1222 tcphdr_t *tcp;
1223 ip_t *ip;
1224 mb_t *m;
1225
1226 m = fin->fin_m;
1227 ip = fin->fin_ip;
1228 tcp = (tcphdr_t *)fin->fin_dp;
1229 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
1230
1231 f = &ftp->ftp_side[rv];
1232 t = &ftp->ftp_side[1 - rv];
1233 thseq = ntohl(tcp->th_seq);
1234 thack = ntohl(tcp->th_ack);
1235 mlen = MSGDSIZE(m) - off;
1236
1237 DT3(process_debug, tcphdr_t *, tcp, int, off, int, mlen);
1238 if (softf->ipf_p_ftp_debug & DEBUG_INFO)
1239 printf("ipf_p_ftp_process: %d:%d,%d, mlen %d flags %x\n",
1240 fin->fin_out, fin->fin_sport, fin->fin_dport,
1241 mlen, tcp_get_flags(tcp));
1242
1243 if ((mlen == 0) && ((tcp_get_flags(tcp) & TH_OPENING) == TH_OPENING)) {
1244 f->ftps_seq[0] = thseq + 1;
1245 t->ftps_seq[0] = thack;
1246 return (0);
1247 } else if (mlen < 0) {
1248 return (0);
1249 }
1250
1251 aps = nat->nat_aps;
1252
1253 sel = aps->aps_sel[1 - rv];
1254 sel2 = aps->aps_sel[rv];
1255 if (rv == 1) {
1256 seqoff = aps->aps_seqoff[sel];
1257 if (aps->aps_seqmin[sel] > seqoff + thseq)
1258 seqoff = aps->aps_seqoff[!sel];
1259 ackoff = aps->aps_ackoff[sel2];
1260 if (aps->aps_ackmin[sel2] > ackoff + thack)
1261 ackoff = aps->aps_ackoff[!sel2];
1262 } else {
1263 seqoff = aps->aps_ackoff[sel];
1264 if (softf->ipf_p_ftp_debug & DEBUG_INFO)
1265 printf("seqoff %d thseq %x ackmin %x\n", seqoff, thseq,
1266 aps->aps_ackmin[sel]);
1267 if (aps->aps_ackmin[sel] > seqoff + thseq)
1268 seqoff = aps->aps_ackoff[!sel];
1269
1270 ackoff = aps->aps_seqoff[sel2];
1271 if (softf->ipf_p_ftp_debug & DEBUG_INFO)
1272 printf("ackoff %d thack %x seqmin %x\n", ackoff, thack,
1273 aps->aps_seqmin[sel2]);
1274 if (ackoff > 0) {
1275 if (aps->aps_seqmin[sel2] > ackoff + thack)
1276 ackoff = aps->aps_seqoff[!sel2];
1277 } else {
1278 if (aps->aps_seqmin[sel2] > thack)
1279 ackoff = aps->aps_seqoff[!sel2];
1280 }
1281 }
1282 if (softf->ipf_p_ftp_debug & DEBUG_INFO) {
1283 printf("%s: %x seq %x/%d ack %x/%d len %d/%d off %d\n",
1284 rv ? "IN" : "OUT", tcp_get_flags(tcp), thseq, seqoff,
1285 thack, ackoff, mlen, fin->fin_plen, off);
1286 printf("sel %d seqmin %x/%x offset %d/%d\n", sel,
1287 aps->aps_seqmin[sel], aps->aps_seqmin[sel2],
1288 aps->aps_seqoff[sel], aps->aps_seqoff[sel2]);
1289 printf("sel %d ackmin %x/%x offset %d/%d\n", sel2,
1290 aps->aps_ackmin[sel], aps->aps_ackmin[sel2],
1291 aps->aps_ackoff[sel], aps->aps_ackoff[sel2]);
1292 }
1293
1294 /*
1295 * XXX - Ideally, this packet should get dropped because we now know
1296 * that it is out of order (and there is no real danger in doing so
1297 * apart from causing packets to go through here ordered).
1298 */
1299 if (softf->ipf_p_ftp_debug & DEBUG_INFO) {
1300 printf("rv %d t:seq[0] %x seq[1] %x %d/%d\n",
1301 rv, t->ftps_seq[0], t->ftps_seq[1], seqoff, ackoff);
1302 }
1303
1304 ok = 0;
1305 if (t->ftps_seq[0] == 0) {
1306 t->ftps_seq[0] = thack;
1307 ok = 1;
1308 } else {
1309 if (ackoff == 0) {
1310 if (t->ftps_seq[0] == thack)
1311 ok = 1;
1312 else if (t->ftps_seq[1] == thack) {
1313 t->ftps_seq[0] = thack;
1314 ok = 1;
1315 }
1316 } else {
1317 if (t->ftps_seq[0] + ackoff == thack) {
1318 t->ftps_seq[0] = thack;
1319 ok = 1;
1320 } else if (t->ftps_seq[0] == thack + ackoff) {
1321 t->ftps_seq[0] = thack + ackoff;
1322 ok = 1;
1323 } else if (t->ftps_seq[1] + ackoff == thack) {
1324 t->ftps_seq[0] = thack;
1325 ok = 1;
1326 } else if (t->ftps_seq[1] == thack + ackoff) {
1327 t->ftps_seq[0] = thack + ackoff;
1328 ok = 1;
1329 }
1330 }
1331 }
1332
1333 if (softf->ipf_p_ftp_debug & DEBUG_INFO) {
1334 if (!ok)
1335 printf("%s ok\n", "not");
1336 }
1337
1338 if (!mlen) {
1339 if (t->ftps_seq[0] + ackoff != thack &&
1340 t->ftps_seq[1] + ackoff != thack) {
1341 DT3(thack, ftpside_t *t, t, int, ackoff, u_32_t, thack);
1342 if (softf->ipf_p_ftp_debug & DEBUG_ERROR) {
1343 printf("%s:seq[0](%u) + (%d) != (%u)\n",
1344 "ipf_p_ftp_process", t->ftps_seq[0],
1345 ackoff, thack);
1346 printf("%s:seq[1](%u) + (%d) != (%u)\n",
1347 "ipf_p_ftp_process", t->ftps_seq[1],
1348 ackoff, thack);
1349 }
1350 return (APR_ERR(1));
1351 }
1352
1353 if (softf->ipf_p_ftp_debug & DEBUG_PARSE) {
1354 printf("ipf_p_ftp_process:f:seq[0] %x seq[1] %x\n",
1355 f->ftps_seq[0], f->ftps_seq[1]);
1356 }
1357
1358 if (tcp_get_flags(tcp) & TH_FIN) {
1359 if (thseq == f->ftps_seq[1]) {
1360 f->ftps_seq[0] = f->ftps_seq[1] - seqoff;
1361 f->ftps_seq[1] = thseq + 1 - seqoff;
1362 } else {
1363 DT2(thseq, ftpside_t *t, t, u_32_t, thseq);
1364 if (softf->ipf_p_ftp_debug & DEBUG_ERROR) {
1365 printf("FIN: thseq %x seqoff %d ftps_seq %x\n",
1366 thseq, seqoff, f->ftps_seq[0]);
1367 }
1368 return (APR_ERR(1));
1369 }
1370 }
1371 f->ftps_len = 0;
1372 return (0);
1373 }
1374
1375 ok = 0;
1376 if ((thseq == f->ftps_seq[0]) || (thseq == f->ftps_seq[1])) {
1377 ok = 1;
1378 /*
1379 * Retransmitted data packet.
1380 */
1381 } else if ((thseq + mlen == f->ftps_seq[0]) ||
1382 (thseq + mlen == f->ftps_seq[1])) {
1383 ok = 1;
1384 }
1385
1386 if (ok == 0) {
1387 DT3(ok_0, ftpside_t *, f, u_32_t, thseq, int, mlen);
1388 inc = thseq - f->ftps_seq[0];
1389 if (softf->ipf_p_ftp_debug & DEBUG_ERROR) {
1390 printf("inc %d sel %d rv %d\n", inc, sel, rv);
1391 printf("th_seq %x ftps_seq %x/%x\n",
1392 thseq, f->ftps_seq[0], f->ftps_seq[1]);
1393 printf("ackmin %x ackoff %d\n", aps->aps_ackmin[sel],
1394 aps->aps_ackoff[sel]);
1395 printf("seqmin %x seqoff %d\n", aps->aps_seqmin[sel],
1396 aps->aps_seqoff[sel]);
1397 }
1398
1399 return (APR_ERR(1));
1400 }
1401
1402 inc = 0;
1403 rptr = f->ftps_rptr;
1404 wptr = f->ftps_wptr;
1405 f->ftps_seq[0] = thseq;
1406 f->ftps_seq[1] = f->ftps_seq[0] + mlen;
1407 f->ftps_len = mlen;
1408
1409 while (mlen > 0) {
1410 len = MIN(mlen, sizeof(f->ftps_buf) - (wptr - rptr));
1411 if (len == 0)
1412 break;
1413 COPYDATA(m, off, len, wptr);
1414 mlen -= len;
1415 off += len;
1416 wptr += len;
1417
1418 whilemore:
1419 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
1420 printf("%s:len %d/%d off %d wptr %lx junk %d [%*.*s]\n",
1421 "ipf_p_ftp_process",
1422 len, mlen, off, (u_long)wptr, f->ftps_junk,
1423 len, len, rptr);
1424
1425 f->ftps_wptr = wptr;
1426 if (f->ftps_junk != FTPXY_JUNK_OK) {
1427 i = f->ftps_junk;
1428 f->ftps_junk = ipf_p_ftp_valid(softf, ftp, rv, rptr,
1429 wptr - rptr);
1430 DT2(junk_transit, int, i, int, f->ftps_junk);
1431
1432 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
1433 printf("%s:junk %d -> %d\n",
1434 "ipf_p_ftp_process", i, f->ftps_junk);
1435
1436 if (f->ftps_junk == FTPXY_JUNK_BAD) {
1437 DT(buffer_full);
1438 if (wptr - rptr == sizeof(f->ftps_buf)) {
1439 if (softf->ipf_p_ftp_debug &
1440 DEBUG_PARSE_INFO)
1441 printf("%s:full buffer\n",
1442 "ipf_p_ftp_process");
1443 f->ftps_rptr = f->ftps_buf;
1444 f->ftps_wptr = f->ftps_buf;
1445 rptr = f->ftps_rptr;
1446 wptr = f->ftps_wptr;
1447 continue;
1448 }
1449 }
1450 }
1451
1452 while ((f->ftps_junk == FTPXY_JUNK_OK) && (wptr > rptr)) {
1453 len = wptr - rptr;
1454 f->ftps_junk = ipf_p_ftp_valid(softf, ftp, rv,
1455 rptr, len);
1456 DT5(junk_ftp_valid, int, len, int, rv, u_long, rptr,
1457 u_long, wptr, int, f->ftps_junk);
1458
1459 if (softf->ipf_p_ftp_debug & DEBUG_PARSE) {
1460 printf("%s=%d len %d rv %d ptr %lx/%lx ",
1461 "ipf_p_ftp_valid",
1462 f->ftps_junk, len, rv, (u_long)rptr,
1463 (u_long)wptr);
1464 printf("buf [%*.*s]\n", len, len, rptr);
1465 }
1466
1467 if (f->ftps_junk == FTPXY_JUNK_OK) {
1468 f->ftps_cmds++;
1469 f->ftps_rptr = rptr;
1470 if (rv)
1471 inc += ipf_p_ftp_server(softf, fin, ip,
1472 nat, ftp, len);
1473 else
1474 inc += ipf_p_ftp_client(softf, fin, ip,
1475 nat, ftp, len);
1476 rptr = f->ftps_rptr;
1477 wptr = f->ftps_wptr;
1478 }
1479 }
1480
1481 /*
1482 * Off to a bad start so lets just forget about using the
1483 * ftp proxy for this connection.
1484 */
1485 if ((f->ftps_cmds == 0) && (f->ftps_junk == FTPXY_JUNK_BAD)) {
1486 /* f->ftps_seq[1] += inc; */
1487
1488 DT(ftp_junk_cmd);
1489 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
1490 printf("%s:cmds == 0 junk == 1\n",
1491 "ipf_p_ftp_process");
1492 return (APR_ERR(2));
1493 }
1494
1495 retry = 0;
1496 if ((f->ftps_junk != FTPXY_JUNK_OK) && (rptr < wptr)) {
1497 for (s = rptr; s < wptr; s++) {
1498 if ((*s == '\r') && (s + 1 < wptr) &&
1499 (*(s + 1) == '\n')) {
1500 rptr = s + 2;
1501 retry = 1;
1502 if (f->ftps_junk != FTPXY_JUNK_CONT)
1503 f->ftps_junk = FTPXY_JUNK_OK;
1504 break;
1505 }
1506 }
1507 }
1508
1509 if (rptr == wptr) {
1510 rptr = wptr = f->ftps_buf;
1511 } else {
1512 /*
1513 * Compact the buffer back to the start. The junk
1514 * flag should already be set and because we're not
1515 * throwing away any data, it is preserved from its
1516 * current state.
1517 */
1518 if (rptr > f->ftps_buf) {
1519 bcopy(rptr, f->ftps_buf, wptr - rptr);
1520 wptr -= rptr - f->ftps_buf;
1521 rptr = f->ftps_buf;
1522 }
1523 }
1524 f->ftps_rptr = rptr;
1525 f->ftps_wptr = wptr;
1526 if (retry)
1527 goto whilemore;
1528 }
1529
1530 /* f->ftps_seq[1] += inc; */
1531 if (tcp_get_flags(tcp) & TH_FIN)
1532 f->ftps_seq[1]++;
1533 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_INFO) {
1534 mlen = MSGDSIZE(m);
1535 mlen -= off;
1536 printf("ftps_seq[1] = %x inc %d len %d\n",
1537 f->ftps_seq[1], inc, mlen);
1538 }
1539
1540 f->ftps_rptr = rptr;
1541 f->ftps_wptr = wptr;
1542 return (APR_INC(inc));
1543 }
1544
1545
1546 int
ipf_p_ftp_out(void * arg,fr_info_t * fin,ap_session_t * aps,nat_t * nat)1547 ipf_p_ftp_out(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat)
1548 {
1549 ipf_ftp_softc_t *softf = arg;
1550 ftpinfo_t *ftp;
1551 int rev;
1552
1553 ftp = aps->aps_data;
1554 if (ftp == NULL)
1555 return (0);
1556
1557 rev = (nat->nat_dir == NAT_OUTBOUND) ? 0 : 1;
1558 if (ftp->ftp_side[1 - rev].ftps_ifp == NULL)
1559 ftp->ftp_side[1 - rev].ftps_ifp = fin->fin_ifp;
1560
1561 return (ipf_p_ftp_process(softf, fin, nat, ftp, rev));
1562 }
1563
1564
1565 int
ipf_p_ftp_in(void * arg,fr_info_t * fin,ap_session_t * aps,nat_t * nat)1566 ipf_p_ftp_in(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat)
1567 {
1568 ipf_ftp_softc_t *softf = arg;
1569 ftpinfo_t *ftp;
1570 int rev;
1571
1572 ftp = aps->aps_data;
1573 if (ftp == NULL)
1574 return (0);
1575
1576 rev = (nat->nat_dir == NAT_OUTBOUND) ? 0 : 1;
1577 if (ftp->ftp_side[rev].ftps_ifp == NULL)
1578 ftp->ftp_side[rev].ftps_ifp = fin->fin_ifp;
1579
1580 return (ipf_p_ftp_process(softf, fin, nat, ftp, 1 - rev));
1581 }
1582
1583
1584 /*
1585 * ipf_p_ftp_atoi - implement a version of atoi which processes numbers in
1586 * pairs separated by commas (which are expected to be in the range 0 - 255),
1587 * returning a 16 bit number combining either side of the , as the MSB and
1588 * LSB.
1589 */
1590 u_short
ipf_p_ftp_atoi(char ** ptr)1591 ipf_p_ftp_atoi(char **ptr)
1592 {
1593 register char *s = *ptr, c;
1594 register u_char i = 0, j = 0;
1595
1596 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1597 i *= 10;
1598 i += c - '0';
1599 }
1600 if (c != ',') {
1601 *ptr = NULL;
1602 return (0);
1603 }
1604 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1605 j *= 10;
1606 j += c - '0';
1607 }
1608 *ptr = s;
1609 i &= 0xff;
1610 j &= 0xff;
1611 return (i << 8) | j;
1612 }
1613
1614
1615 int
ipf_p_ftp_eprt(ipf_ftp_softc_t * softf,fr_info_t * fin,ip_t * ip,nat_t * nat,ftpinfo_t * ftp,int dlen)1616 ipf_p_ftp_eprt(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat,
1617 ftpinfo_t *ftp, int dlen)
1618 {
1619 ftpside_t *f;
1620
1621 /*
1622 * Check for client sending out EPRT message.
1623 */
1624 if (dlen < IPF_MINEPRTLEN) {
1625 DT1(epert_dlen, int, dlen);
1626 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
1627 printf("ipf_p_ftp_eprt:dlen(%d) < IPF_MINEPRTLEN\n",
1628 dlen);
1629 return (0);
1630 }
1631
1632 /*
1633 * Parse the EPRT command. Format is:
1634 * "EPRT |1|1.2.3.4|2000|" for IPv4 and
1635 * "EPRT |2|ef00::1:2|2000|" for IPv6
1636 */
1637 f = &ftp->ftp_side[0];
1638 if (f->ftps_rptr[5] != '|')
1639 return (0);
1640 if (f->ftps_rptr[5] == f->ftps_rptr[7]) {
1641 if (f->ftps_rptr[6] == '1' && nat->nat_v[0] == 4)
1642 return (ipf_p_ftp_eprt4(softf, fin, ip, nat, ftp, dlen));
1643 #ifdef USE_INET6
1644 if (f->ftps_rptr[6] == '2' && nat->nat_v[0] == 6)
1645 return (ipf_p_ftp_eprt6(softf, fin, ip, nat, ftp, dlen));
1646 #endif
1647 }
1648 return (0);
1649 }
1650
1651
1652 int
ipf_p_ftp_eprt4(ipf_ftp_softc_t * softf,fr_info_t * fin,ip_t * ip,nat_t * nat,ftpinfo_t * ftp,int dlen)1653 ipf_p_ftp_eprt4(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat,
1654 ftpinfo_t *ftp, int dlen)
1655 {
1656 int a1, a2, a3, a4, port, olen, nlen, inc, off;
1657 char newbuf[IPF_FTPBUFSZ];
1658 char *s, c, delim;
1659 u_32_t addr, i;
1660 tcphdr_t *tcp;
1661 ftpside_t *f;
1662 mb_t *m;
1663
1664 m = fin->fin_m;
1665 tcp = (tcphdr_t *)fin->fin_dp;
1666 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
1667 f = &ftp->ftp_side[0];
1668 delim = f->ftps_rptr[5];
1669 s = f->ftps_rptr + 8;
1670
1671 /*
1672 * get the IP address.
1673 */
1674 i = 0;
1675 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1676 i *= 10;
1677 i += c - '0';
1678 }
1679 if (i > 255)
1680 return (0);
1681 if (c != '.')
1682 return (0);
1683 addr = (i << 24);
1684
1685 i = 0;
1686 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1687 i *= 10;
1688 i += c - '0';
1689 }
1690 if (i > 255)
1691 return (0);
1692 if (c != '.')
1693 return (0);
1694 addr |= (addr << 16);
1695
1696 i = 0;
1697 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1698 i *= 10;
1699 i += c - '0';
1700 }
1701 if (i > 255)
1702 return (0);
1703 if (c != '.')
1704 return (0);
1705 addr |= (addr << 8);
1706
1707 i = 0;
1708 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1709 i *= 10;
1710 i += c - '0';
1711 }
1712 if (i > 255)
1713 return (0);
1714 if (c != delim)
1715 return (0);
1716 #if 0
1717 addr |= (addr << 0);
1718 #endif
1719
1720 /*
1721 * Get the port number
1722 */
1723 i = 0;
1724 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1725 i *= 10;
1726 i += c - '0';
1727 }
1728 if (i > 65535)
1729 return (0);
1730 if (c != delim)
1731 return (0);
1732 port = i;
1733
1734 /*
1735 * Check for CR-LF at the end of the command string.
1736 */
1737 if ((*s != '\r') || (*(s + 1) != '\n')) {
1738 DT(eprt4_no_crlf);
1739 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
1740 printf("ipf_p_ftp_eprt4:missing %s\n", "cr-lf");
1741 return (0);
1742 }
1743 s += 2;
1744
1745 /*
1746 * Calculate new address parts for PORT command
1747 */
1748 if (nat->nat_dir == NAT_INBOUND)
1749 a1 = ntohl(nat->nat_odstaddr);
1750 else
1751 a1 = ntohl(ip->ip_src.s_addr);
1752 a2 = (a1 >> 16) & 0xff;
1753 a3 = (a1 >> 8) & 0xff;
1754 a4 = a1 & 0xff;
1755 a1 >>= 24;
1756 olen = s - f->ftps_rptr;
1757 /* DO NOT change this to snprintf! */
1758 /*
1759 * While we could force the use of | as a delimiter here, it makes
1760 * sense to preserve whatever character is being used by the systems
1761 * involved in the communication.
1762 */
1763 (void) snprintf(newbuf, sizeof(newbuf), "%s %c1%c%u.%u.%u.%u%c%u%c\r\n",
1764 "EPRT", delim, delim, a1, a2, a3, a4, delim, port,
1765 delim);
1766
1767 nlen = strlen(newbuf);
1768 inc = nlen - olen;
1769 if ((inc + fin->fin_plen) > 65535) {
1770 DT2(eprt4_len, int, inc, int, fin->fin_plen);
1771 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
1772 printf("ipf_p_ftp_eprt4:inc(%d) + ip->ip_len > 65535\n",
1773 inc);
1774 return (0);
1775 }
1776
1777 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
1778 #if !defined(_KERNEL)
1779 M_ADJ(m, inc);
1780 #else
1781 if (inc < 0)
1782 M_ADJ(m, inc);
1783 #endif
1784 /* the mbuf chain will be extended if necessary by m_copyback() */
1785 COPYBACK(m, off, nlen, newbuf);
1786 fin->fin_flx |= FI_DOCKSUM;
1787
1788 if (inc != 0) {
1789 fin->fin_plen += inc;
1790 ip->ip_len = htons(fin->fin_plen);
1791 fin->fin_dlen += inc;
1792 }
1793
1794 f->ftps_cmd = FTPXY_C_EPRT;
1795 return (ipf_p_ftp_addport(softf, fin, ip, nat, ftp, dlen, port, inc));
1796 }
1797
1798
1799 int
ipf_p_ftp_epsv(ipf_ftp_softc_t * softf,fr_info_t * fin,ip_t * ip,nat_t * nat,ftpinfo_t * ftp,int dlen)1800 ipf_p_ftp_epsv(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat,
1801 ftpinfo_t *ftp, int dlen)
1802 {
1803 char newbuf[IPF_FTPBUFSZ];
1804 u_short ap = 0;
1805 ftpside_t *f;
1806 char *s;
1807
1808 if ((softf->ipf_p_ftp_forcepasv != 0) &&
1809 (ftp->ftp_side[0].ftps_cmd != FTPXY_C_EPSV)) {
1810 DT1(epsv_cmd, int, ftp->ftp_side[0].ftps_cmd);
1811 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
1812 printf("ipf_p_ftp_epsv:ftps_cmd(%d) != FTPXY_C_EPSV\n",
1813 ftp->ftp_side[0].ftps_cmd);
1814 return (0);
1815 }
1816 f = &ftp->ftp_side[1];
1817
1818 #define EPSV_REPLEN 33
1819 /*
1820 * Check for EPSV reply message.
1821 */
1822 if (dlen < IPF_MIN229LEN) {
1823 return (0);
1824 } else if (strncmp(f->ftps_rptr,
1825 "229 Entering Extended Passive Mode", EPSV_REPLEN)) {
1826 return (0);
1827 }
1828
1829 /*
1830 * Skip the EPSV command + space
1831 */
1832 s = f->ftps_rptr + 33;
1833 while (*s && !ISDIGIT(*s))
1834 s++;
1835
1836 /*
1837 * As per RFC 2428, there are no address components in the EPSV
1838 * response. So we'll go straight to getting the port.
1839 */
1840 while (*s && ISDIGIT(*s)) {
1841 ap *= 10;
1842 ap += *s++ - '0';
1843 }
1844
1845 if (*s == '|')
1846 s++;
1847 if (*s == ')')
1848 s++;
1849 if (*s == '\n')
1850 s--;
1851 /*
1852 * check for CR-LF at the end.
1853 */
1854 if ((*s != '\r') || (*(s + 1) != '\n')) {
1855 return (0);
1856 }
1857 s += 2;
1858
1859 (void) snprintf(newbuf, sizeof(newbuf), "%s (|||%u|)\r\n",
1860 "229 Entering Extended Passive Mode", ap);
1861
1862 return (ipf_p_ftp_pasvreply(softf, fin, ip, nat, ftp, (u_int)ap,
1863 newbuf, s));
1864 }
1865
1866 #ifdef USE_INET6
1867 int
ipf_p_ftp_eprt6(ipf_ftp_softc_t * softf,fr_info_t * fin,ip_t * ip,nat_t * nat,ftpinfo_t * ftp,int dlen)1868 ipf_p_ftp_eprt6(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat,
1869 ftpinfo_t *ftp, int dlen)
1870 {
1871 int port, olen, nlen, inc, off, left, i;
1872 char newbuf[IPF_FTPBUFSZ];
1873 char *s, c;
1874 i6addr_t addr, *a6;
1875 tcphdr_t *tcp;
1876 ip6_t *ip6;
1877 char delim;
1878 u_short whole;
1879 u_short part;
1880 ftpside_t *f;
1881 u_short *t;
1882 int fwd;
1883 mb_t *m;
1884 u_32_t a;
1885
1886 m = fin->fin_m;
1887 ip6 = (ip6_t *)ip;
1888 f = &ftp->ftp_side[0];
1889 s = f->ftps_rptr + 8;
1890 f = &ftp->ftp_side[0];
1891 delim = f->ftps_rptr[5];
1892 tcp = (tcphdr_t *)fin->fin_dp;
1893 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
1894
1895 addr.i6[0] = 0;
1896 addr.i6[1] = 0;
1897 addr.i6[2] = 0;
1898 addr.i6[3] = 0;
1899 /*
1900 * Parse an IPv6 address.
1901 * Go forward until either :: or | is found. If :: is found,
1902 * reverse direction. Direction change is performed to ease
1903 * parsing an unknown number of 0s in the middle.
1904 */
1905 whole = 0;
1906 t = (u_short *)&addr;
1907 fwd = 1;
1908 for (part = 0; (c = *s) != '\0'; ) {
1909 if (c == delim) {
1910 *t = htons((u_short)whole);
1911 break;
1912 }
1913 if (c == ':') {
1914 *t = part;
1915 if (fwd) {
1916 *t = htons((u_short)whole);
1917 t++;
1918 } else {
1919 *t = htons((u_short)(whole >> 16));
1920 t--;
1921 }
1922 whole = 0;
1923 if (fwd == 1 && s[1] == ':') {
1924 while (*s && *s != '|')
1925 s++;
1926 if ((c = *s) != delim)
1927 break;
1928 t = (u_short *)&addr.i6[3];
1929 t++;
1930 fwd = 0;
1931 } else if (fwd == 0 && s[-1] == ':') {
1932 break;
1933 }
1934 } else {
1935 if (c >= '0' && c <= '9') {
1936 c -= '0';
1937 } else if (c >= 'a' && c <= 'f') {
1938 c -= 'a' + 10;
1939 } else if (c >= 'A' && c <= 'F') {
1940 c -= 'A' + 10;
1941 }
1942 if (fwd) {
1943 whole <<= 8;
1944 whole |= c;
1945 } else {
1946 whole >>= 8;
1947 whole |= ((u_32_t)c) << 24;
1948 }
1949 }
1950 if (fwd)
1951 s++;
1952 else
1953 s--;
1954 }
1955 if (c != ':' && c != delim)
1956 return (0);
1957
1958 while (*s != '|')
1959 s++;
1960 s++;
1961
1962 /*
1963 * Get the port number
1964 */
1965 i = 0;
1966 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1967 i *= 10;
1968 i += c - '0';
1969 }
1970 if (i > 65535)
1971 return (0);
1972 if (c != delim)
1973 return (0);
1974 port = (u_short)(i & 0xffff);
1975
1976 /*
1977 * Check for CR-LF at the end of the command string.
1978 */
1979 if ((*s != '\r') || (*(s + 1) != '\n')) {
1980 DT(eprt6_no_crlf);
1981 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
1982 printf("ipf_p_ftp_eprt6:missing %s\n", "cr-lf");
1983 return (0);
1984 }
1985 s += 2;
1986
1987 /*
1988 * Calculate new address parts for PORT command
1989 */
1990 a6 = (i6addr_t *)&ip6->ip6_src;
1991 olen = s - f->ftps_rptr;
1992 /* DO NOT change this to snprintf! */
1993 /*
1994 * While we could force the use of | as a delimiter here, it makes
1995 * sense to preserve whatever character is being used by the systems
1996 * involved in the communication.
1997 */
1998 s = newbuf;
1999 left = sizeof(newbuf);
2000 (void) snprintf(s, left, "EPRT %c2%c", delim, delim);
2001 s += strlen(s);
2002 a = ntohl(a6->i6[0]);
2003 snprintf(s, left, "%x:%x:", a >> 16, a & 0xffff);
2004 left -= strlen(s);
2005 s += strlen(s);
2006 a = ntohl(a6->i6[1]);
2007 snprintf(s, left, "%x:%x:", a >> 16, a & 0xffff);
2008 left -= strlen(s);
2009 s += strlen(s);
2010 a = ntohl(a6->i6[2]);
2011 snprintf(s, left,"%x:%x:", a >> 16, a & 0xffff);
2012 left -= strlen(s);
2013 s += strlen(s);
2014 a = ntohl(a6->i6[3]);
2015 snprintf(s, left, "%x:%x", a >> 16, a & 0xffff);
2016 left -= strlen(s);
2017 s += strlen(s);
2018 snprintf(s, left, "|%d|\r\n", port);
2019 nlen = strlen(newbuf);
2020 inc = nlen - olen;
2021 if ((inc + fin->fin_plen) > 65535) {
2022 DT2(eprt6_len, int, inc, int, fin->fin_plen);
2023 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
2024 printf("ipf_p_ftp_eprt6:inc(%d) + ip->ip_len > 65535\n",
2025 inc);
2026 return (0);
2027 }
2028
2029 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
2030 #if !defined(_KERNEL)
2031 M_ADJ(m, inc);
2032 #else
2033 if (inc < 0)
2034 M_ADJ(m, inc);
2035 #endif
2036 /* the mbuf chain will be extended if necessary by m_copyback() */
2037 COPYBACK(m, off, nlen, newbuf);
2038 fin->fin_flx |= FI_DOCKSUM;
2039
2040 if (inc != 0) {
2041 fin->fin_plen += inc;
2042 ip6->ip6_plen = htons(fin->fin_plen - fin->fin_hlen);
2043 fin->fin_dlen += inc;
2044 }
2045
2046 f->ftps_cmd = FTPXY_C_EPRT;
2047 return (ipf_p_ftp_addport(softf, fin, ip, nat, ftp, dlen, port, inc));
2048 }
2049 #endif
2050