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)222 ipf_p_ftp_new(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat)
223 {
224 ftpinfo_t *ftp;
225 ftpside_t *f;
226
227 KMALLOC(ftp, ftpinfo_t *);
228 if (ftp == NULL)
229 return (-1);
230
231 nat = nat; /* LINT */
232
233 aps->aps_data = ftp;
234 aps->aps_psiz = sizeof(ftpinfo_t);
235 aps->aps_sport = htons(fin->fin_sport);
236 aps->aps_dport = htons(fin->fin_dport);
237
238 bzero((char *)ftp, sizeof(*ftp));
239 f = &ftp->ftp_side[0];
240 f->ftps_rptr = f->ftps_buf;
241 f->ftps_wptr = f->ftps_buf;
242 f = &ftp->ftp_side[1];
243 f->ftps_rptr = f->ftps_buf;
244 f->ftps_wptr = f->ftps_buf;
245 ftp->ftp_passok = FTPXY_INIT;
246 ftp->ftp_incok = 0;
247 return (0);
248 }
249
250
251 void
ipf_p_ftp_setpending(ipf_main_softc_t * softc,ftpinfo_t * ftp)252 ipf_p_ftp_setpending(ipf_main_softc_t *softc, ftpinfo_t *ftp)
253 {
254 if (ftp->ftp_pendnat != NULL)
255 ipf_nat_setpending(softc, ftp->ftp_pendnat);
256
257 if (ftp->ftp_pendstate != NULL) {
258 READ_ENTER(&softc->ipf_state);
259 ipf_state_setpending(softc, ftp->ftp_pendstate);
260 RWLOCK_EXIT(&softc->ipf_state);
261 }
262 }
263
264
265 void
ipf_p_ftp_del(ipf_main_softc_t * softc,ap_session_t * aps)266 ipf_p_ftp_del(ipf_main_softc_t *softc, ap_session_t *aps)
267 {
268 ftpinfo_t *ftp;
269
270 ftp = aps->aps_data;
271 if (ftp != NULL)
272 ipf_p_ftp_setpending(softc, ftp);
273 }
274
275
276 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)277 ipf_p_ftp_port(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat,
278 ftpinfo_t *ftp, int dlen)
279 {
280 char newbuf[IPF_FTPBUFSZ], *s;
281 u_int a1, a2, a3, a4;
282 u_short a5, a6, sp;
283 size_t nlen, olen;
284 tcphdr_t *tcp;
285 int inc, off;
286 ftpside_t *f;
287 mb_t *m;
288
289 m = fin->fin_m;
290 f = &ftp->ftp_side[0];
291 tcp = (tcphdr_t *)fin->fin_dp;
292 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
293
294 /*
295 * Check for client sending out PORT message.
296 */
297 if (dlen < IPF_MINPORTLEN) {
298 DT3(ftp_PORT_error_dlen, nat_t *, nat, ftpside_t *, f,
299 u_int, dlen);
300 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
301 printf("ipf_p_ftp_port:dlen(%d) < IPF_MINPORTLEN\n",
302 dlen);
303 return (0);
304 }
305 /*
306 * Skip the PORT command + space
307 */
308 s = f->ftps_rptr + 5;
309 /*
310 * Pick out the address components, two at a time.
311 */
312 a1 = ipf_p_ftp_atoi(&s);
313 if (s == NULL) {
314 DT2(ftp_PORT_error_atoi_1, nat_t *, nat, ftpside_t *, f);
315 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
316 printf("ipf_p_ftp_port:ipf_p_ftp_atoi(%d) failed\n", 1);
317 return (0);
318 }
319 a2 = ipf_p_ftp_atoi(&s);
320 if (s == NULL) {
321 DT2(ftp_PORT_error_atoi_2, nat_t *, nat, ftpside_t *, f);
322 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
323 printf("ipf_p_ftp_port:ipf_p_ftp_atoi(%d) failed\n", 2);
324 return (0);
325 }
326
327 /*
328 * Check that IP address in the PORT/PASV reply is the same as the
329 * sender of the command - prevents using PORT for port scanning.
330 */
331 a1 <<= 16;
332 a1 |= a2;
333 if (((nat->nat_dir == NAT_OUTBOUND) &&
334 (a1 != ntohl(nat->nat_osrcaddr))) ||
335 ((nat->nat_dir == NAT_INBOUND) &&
336 (a1 != ntohl(nat->nat_nsrcaddr)))) {
337 DT3(ftp_PORT_error_address, nat_t *, nat, ftpside_t *, f,
338 u_int, a1);
339 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
340 printf("ipf_p_ftp_port:%s != nat->nat_inip\n", "a1");
341 return (APR_ERR(1));
342 }
343
344 a5 = ipf_p_ftp_atoi(&s);
345 if (s == NULL) {
346 DT2(ftp_PORT_error_atoi_3, nat_t *, nat, ftpside_t *, f);
347 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
348 printf("ipf_p_ftp_port:ipf_p_ftp_atoi(%d) failed\n", 3);
349 return (0);
350 }
351 if (*s == ')')
352 s++;
353
354 /*
355 * check for CR-LF at the end.
356 */
357 if (*s == '\n')
358 s--;
359 if ((*s != '\r') || (*(s + 1) != '\n')) {
360 DT2(ftp_PORT_error_no_crlf, nat_t *, nat, ftpside_t *, f);
361 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
362 printf("ipf_p_ftp_port:missing %s\n", "cr-lf");
363 return (0);
364 }
365 s += 2;
366 a6 = a5 & 0xff;
367
368 /*
369 * Calculate the source port. Verification of > 1024 is in
370 * ipf_p_ftp_addport.
371 */
372 a5 >>= 8;
373 a5 &= 0xff;
374 sp = a5 << 8 | a6;
375
376 /*
377 * Calculate new address parts for PORT command
378 */
379 if (nat->nat_dir == NAT_INBOUND)
380 a1 = ntohl(nat->nat_ndstaddr);
381 else
382 a1 = ntohl(ip->ip_src.s_addr);
383 a1 = ntohl(ip->ip_src.s_addr);
384 a2 = (a1 >> 16) & 0xff;
385 a3 = (a1 >> 8) & 0xff;
386 a4 = a1 & 0xff;
387 a1 >>= 24;
388 olen = s - f->ftps_rptr;
389 (void) snprintf(newbuf, sizeof(newbuf), "%s %u,%u,%u,%u,%u,%u\r\n",
390 "PORT", a1, a2, a3, a4, a5, a6);
391
392 nlen = strlen(newbuf);
393 inc = nlen - olen;
394 if ((inc + fin->fin_plen) > 65535) {
395 DT3(ftp_PORT_error_inc, nat_t *, nat, ftpside_t *, f,
396 int, inc);
397 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
398 printf("ipf_p_ftp_port:inc(%d) + ip->ip_len > 65535\n",
399 inc);
400 return (0);
401 }
402
403 #if !defined(_KERNEL)
404 M_ADJ(m, inc);
405 #else
406 /*
407 * m_adj takes care of pkthdr.len, if required and treats inc<0 to
408 * mean remove -len bytes from the end of the packet.
409 * The mbuf chain will be extended if necessary by m_copyback().
410 */
411 if (inc < 0)
412 M_ADJ(m, inc);
413 #endif /* !defined(_KERNEL) */
414 COPYBACK(m, off, nlen, newbuf);
415 fin->fin_flx |= FI_DOCKSUM;
416
417 if (inc != 0) {
418 fin->fin_plen += inc;
419 ip->ip_len = htons(fin->fin_plen);
420 fin->fin_dlen += inc;
421 }
422
423 f->ftps_cmd = FTPXY_C_PORT;
424 return (ipf_p_ftp_addport(softf, fin, ip, nat, ftp, dlen, sp, inc));
425 }
426
427
428 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)429 ipf_p_ftp_addport(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat,
430 ftpinfo_t *ftp, int dlen, int nport, int inc)
431 {
432 tcphdr_t tcph, *tcp2 = &tcph;
433 ipf_main_softc_t *softc;
434 ipf_nat_softc_t *softn;
435 int direction;
436 fr_info_t fi;
437 ipnat_t *ipn;
438 nat_t *nat2;
439 u_short sp;
440 int flags;
441
442 softc = fin->fin_main_soft;
443 softn = softc->ipf_nat_soft;
444
445 if ((ftp->ftp_pendnat != NULL) || (ftp->ftp_pendstate != NULL)) {
446 if (softf->ipf_p_ftp_single_xfer != 0) {
447 DT2(ftp_PORT_error_add_active, nat_t *, nat,
448 ftpinfo_t *, ftp);
449 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
450 printf("ipf_p_ftp_addport:xfer active %p/%p\n",
451 ftp->ftp_pendnat, ftp->ftp_pendstate);
452 return (0);
453 }
454 ipf_p_ftp_setpending(softc, ftp);
455 }
456
457 /*
458 * Add skeleton NAT entry for connection which will come back the
459 * other way.
460 */
461 sp = nport;
462 /*
463 * Don't allow the PORT command to specify a port < 1024 due to
464 * security risks.
465 */
466 if (sp < 1024) {
467 DT3(ftp_PORT_error_port, nat_t *, nat, ftpinfo_t *, ftp,
468 u_int, sp);
469 if (softf->ipf_p_ftp_debug & DEBUG_SECURITY)
470 printf("ipf_p_ftp_addport:sp(%d) < 1024\n", sp);
471 return (0);
472 }
473 /*
474 * The server may not make the connection back from port 20, but
475 * it is the most likely so use it here to check for a conflicting
476 * mapping.
477 */
478 bcopy((char *)fin, (char *)&fi, sizeof(fi));
479 fi.fin_flx |= FI_IGNORE;
480 fi.fin_data[0] = sp;
481 fi.fin_data[1] = fin->fin_data[1] - 1;
482 fi.fin_src6 = nat->nat_ndst6;
483 fi.fin_dst6 = nat->nat_nsrc6;
484
485 #ifndef USE_INET6
486 if (nat->nat_v[0] == 6)
487 return (APR_INC(inc));
488 #endif
489
490 /*
491 * If an existing entry already exists, use it instead.
492 */
493 #ifdef USE_INET6
494 if (nat->nat_v[0] == 6) {
495 if (nat->nat_dir == NAT_OUTBOUND) {
496 nat2 = ipf_nat6_outlookup(&fi, IPN_TCP|NAT_SEARCH,
497 nat->nat_pr[1],
498 &nat->nat_osrc6.in6,
499 &nat->nat_odst6.in6);
500 } else {
501 nat2 = ipf_nat6_inlookup(&fi, IPN_TCP|NAT_SEARCH,
502 nat->nat_pr[0],
503 &nat->nat_odst6.in6,
504 &nat->nat_osrc6.in6);
505 }
506 } else
507 #endif
508 {
509 if (nat->nat_dir == NAT_OUTBOUND) {
510 nat2 = ipf_nat_outlookup(&fi, IPN_TCP|NAT_SEARCH,
511 nat->nat_pr[1],
512 nat->nat_osrcip,
513 nat->nat_odstip);
514 } else {
515 nat2 = ipf_nat_inlookup(&fi, IPN_TCP|NAT_SEARCH,
516 nat->nat_pr[0],
517 nat->nat_odstip,
518 nat->nat_osrcip);
519 }
520 }
521 if (nat2 != NULL)
522 return (APR_INC(inc));
523
524 /*
525 * An existing entry doesn't exist. Let's make one.
526 */
527 ipn = ipf_proxy_rule_rev(nat);
528 if (ipn == NULL)
529 return (APR_ERR(1));
530 ipn->in_use = 0;
531
532 fi.fin_fr = &ftppxyfr;
533 fi.fin_dp = (char *)tcp2;
534 fi.fin_dlen = sizeof(*tcp2);
535 fi.fin_plen = fi.fin_hlen + sizeof(*tcp2);
536 fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE;
537 fi.fin_data[1] = sp;
538 fi.fin_data[0] = 0;
539
540 bzero((char *)tcp2, sizeof(*tcp2));
541 tcp2->th_sport = 0;
542 tcp2->th_dport = htons(sp);
543
544 tcp2->th_win = htons(8192);
545 TCP_OFF_A(tcp2, 5);
546 tcp_set_flags(tcp2, TH_SYN);
547
548 if (nat->nat_dir == NAT_INBOUND) {
549 fi.fin_out = 1;
550 direction = NAT_OUTBOUND;
551 } else {
552 fi.fin_out = 0;
553 direction = NAT_INBOUND;
554 }
555 flags = SI_W_SPORT|NAT_SLAVE|IPN_TCP;
556
557 MUTEX_ENTER(&softn->ipf_nat_new);
558 #ifdef USE_INET6
559 if (nat->nat_v[0] == 6)
560 nat2 = ipf_nat6_add(&fi, ipn, &ftp->ftp_pendnat, flags,
561 direction);
562 else
563 #endif
564 nat2 = ipf_nat_add(&fi, ipn, &ftp->ftp_pendnat, flags,
565 direction);
566 MUTEX_EXIT(&softn->ipf_nat_new);
567
568 if (nat2 == NULL) {
569 KFREES(ipn, ipn->in_size);
570 return (APR_ERR(1));
571 }
572
573 (void) ipf_nat_proto(&fi, nat2, IPN_TCP);
574 MUTEX_ENTER(&nat2->nat_lock);
575 ipf_nat_update(&fi, nat2);
576 MUTEX_EXIT(&nat2->nat_lock);
577 fi.fin_ifp = NULL;
578 if (nat2->nat_dir == NAT_INBOUND)
579 fi.fin_dst6 = nat->nat_osrc6;
580 if (ipf_state_add(softc, &fi, (ipstate_t **)&ftp->ftp_pendstate,
581 SI_W_SPORT) != 0)
582 ipf_nat_setpending(softc, nat2);
583
584 return (APR_INC(inc));
585 }
586
587
588 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)589 ipf_p_ftp_client(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip,
590 nat_t *nat, ftpinfo_t *ftp, int dlen)
591 {
592 char *rptr, *wptr, cmd[6], c;
593 ftpside_t *f;
594 int inc, i;
595
596 inc = 0;
597 f = &ftp->ftp_side[0];
598 rptr = f->ftps_rptr;
599 wptr = f->ftps_wptr;
600
601 for (i = 0; (i < 5) && (i < dlen); i++) {
602 c = rptr[i];
603 if (ISALPHA(c)) {
604 cmd[i] = TOUPPER(c);
605 } else {
606 cmd[i] = c;
607 }
608 }
609 cmd[i] = '\0';
610
611 ftp->ftp_incok = 0;
612 DT2(ftp_client_command, char [], cmd, int, ftp->ftp_passok);
613 if (!strncmp(cmd, "USER ", 5) || !strncmp(cmd, "XAUT ", 5)) {
614 if (ftp->ftp_passok == FTPXY_ADOK_1 ||
615 ftp->ftp_passok == FTPXY_AUOK_1) {
616 ftp->ftp_passok = FTPXY_USER_2;
617 ftp->ftp_incok = 1;
618 } else {
619 ftp->ftp_passok = FTPXY_USER_1;
620 ftp->ftp_incok = 1;
621 }
622 } else if (!strncmp(cmd, "AUTH ", 5)) {
623 ftp->ftp_passok = FTPXY_AUTH_1;
624 ftp->ftp_incok = 1;
625 } else if (!strncmp(cmd, "PASS ", 5)) {
626 if (ftp->ftp_passok == FTPXY_USOK_1) {
627 ftp->ftp_passok = FTPXY_PASS_1;
628 ftp->ftp_incok = 1;
629 } else if (ftp->ftp_passok == FTPXY_USOK_2) {
630 ftp->ftp_passok = FTPXY_PASS_2;
631 ftp->ftp_incok = 1;
632 }
633 } else if ((ftp->ftp_passok == FTPXY_AUOK_1) &&
634 !strncmp(cmd, "ADAT ", 5)) {
635 ftp->ftp_passok = FTPXY_ADAT_1;
636 ftp->ftp_incok = 1;
637 } else if ((ftp->ftp_passok == FTPXY_PAOK_1 ||
638 ftp->ftp_passok == FTPXY_PAOK_2) &&
639 !strncmp(cmd, "ACCT ", 5)) {
640 ftp->ftp_passok = FTPXY_ACCT_1;
641 ftp->ftp_incok = 1;
642 } else if ((ftp->ftp_passok == FTPXY_GO) &&
643 !softf->ipf_p_ftp_pasvonly &&
644 !strncmp(cmd, "PORT ", 5)) {
645 inc = ipf_p_ftp_port(softf, fin, ip, nat, ftp, dlen);
646 } else if ((ftp->ftp_passok == FTPXY_GO) &&
647 !softf->ipf_p_ftp_pasvonly &&
648 !strncmp(cmd, "EPRT ", 5)) {
649 inc = ipf_p_ftp_eprt(softf, fin, ip, nat, ftp, dlen);
650 } else if (softf->ipf_p_ftp_insecure &&
651 !softf->ipf_p_ftp_pasvonly &&
652 !strncmp(cmd, "PORT ", 5)) {
653 inc = ipf_p_ftp_port(softf, fin, ip, nat, ftp, dlen);
654 }
655 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
656 printf("ipf_p_ftp_client: cmd[%s] passok %d incok %d inc %d\n",
657 cmd, ftp->ftp_passok, ftp->ftp_incok, inc);
658
659 DT2(ftp_client_passok, char *, cmd, int, ftp->ftp_passok);
660 while ((*rptr++ != '\n') && (rptr < wptr))
661 ;
662 f->ftps_rptr = rptr;
663 return (inc);
664 }
665
666
667 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)668 ipf_p_ftp_pasv(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat,
669 ftpinfo_t *ftp, int dlen)
670 {
671 u_int a1, a2, a3, a4, data_ip;
672 char newbuf[IPF_FTPBUFSZ];
673 const char *brackets[2];
674 u_short a5, a6;
675 ftpside_t *f;
676 char *s;
677
678 if ((softf->ipf_p_ftp_forcepasv != 0) &&
679 (ftp->ftp_side[0].ftps_cmd != FTPXY_C_PASV)) {
680 DT2(ftp_PASV_error_state, nat_t *, nat, ftpinfo_t *, ftp);
681 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
682 printf("ipf_p_ftp_pasv:ftps_cmd(%d) != FTPXY_C_PASV\n",
683 ftp->ftp_side[0].ftps_cmd);
684 return (0);
685 }
686
687 f = &ftp->ftp_side[1];
688
689 #define PASV_REPLEN 24
690 /*
691 * Check for PASV reply message.
692 */
693 if (dlen < IPF_MIN227LEN) {
694 DT3(ftp_PASV_error_short, nat_t *, nat, ftpinfo_t *, ftp,
695 int, dlen);
696 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
697 printf("ipf_p_ftp_pasv:dlen(%d) < IPF_MIN227LEN\n",
698 dlen);
699 return (0);
700 } else if (strncmp(f->ftps_rptr,
701 "227 Entering Passive Mod", PASV_REPLEN)) {
702 DT2(ftp_PASV_error_string, nat_t *, nat, ftpinfo_t *, ftp);
703 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
704 printf("ipf_p_ftp_pasv:%d reply wrong\n", 227);
705 return (0);
706 }
707
708 brackets[0] = "";
709 brackets[1] = "";
710 /*
711 * Skip the PASV reply + space
712 */
713 s = f->ftps_rptr + PASV_REPLEN;
714 while (*s && !ISDIGIT(*s)) {
715 if (*s == '(') {
716 brackets[0] = "(";
717 brackets[1] = ")";
718 }
719 s++;
720 }
721
722 /*
723 * Pick out the address components, two at a time.
724 */
725 a1 = ipf_p_ftp_atoi(&s);
726 if (s == NULL) {
727 DT2(ftp_PASV_error_atoi_1, nat_t *, nat, ftpside_t *, f);
728 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
729 printf("ipf_p_ftp_pasv:ipf_p_ftp_atoi(%d) failed\n", 1);
730 return (0);
731 }
732 a2 = ipf_p_ftp_atoi(&s);
733 if (s == NULL) {
734 DT2(ftp_PASV_error_atoi_2, nat_t *, nat, ftpside_t *, f);
735 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
736 printf("ipf_p_ftp_pasv:ipf_p_ftp_atoi(%d) failed\n", 2);
737 return (0);
738 }
739
740 /*
741 * check that IP address in the PASV reply is the same as the
742 * sender of the command - prevents using PASV for port scanning.
743 */
744 a1 <<= 16;
745 a1 |= a2;
746
747 if (((nat->nat_dir == NAT_INBOUND) &&
748 (a1 != ntohl(nat->nat_ndstaddr))) ||
749 ((nat->nat_dir == NAT_OUTBOUND) &&
750 (a1 != ntohl(nat->nat_odstaddr)))) {
751 DT3(ftp_PASV_error_address, nat_t *, nat, ftpside_t *, f,
752 u_int, a1);
753 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
754 printf("ipf_p_ftp_pasv:%s != nat->nat_oip\n", "a1");
755 return (0);
756 }
757
758 a5 = ipf_p_ftp_atoi(&s);
759 if (s == NULL) {
760 DT2(ftp_PASV_error_atoi_3, nat_t *, nat, ftpside_t *, f);
761 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
762 printf("ipf_p_ftp_pasv:ipf_p_ftp_atoi(%d) failed\n", 3);
763 return (0);
764 }
765
766 if (*s == ')')
767 s++;
768 if (*s == '.')
769 s++;
770 if (*s == '\n')
771 s--;
772 /*
773 * check for CR-LF at the end.
774 */
775 if ((*s != '\r') || (*(s + 1) != '\n')) {
776 DT(pasv_missing_crlf);
777 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
778 printf("ipf_p_ftp_pasv:missing %s", "cr-lf\n");
779 return (0);
780 }
781 s += 2;
782
783 a6 = a5 & 0xff;
784 a5 >>= 8;
785 /*
786 * Calculate new address parts for 227 reply
787 */
788 if (nat->nat_dir == NAT_INBOUND) {
789 data_ip = nat->nat_odstaddr;
790 a1 = ntohl(data_ip);
791 } else
792 data_ip = htonl(a1);
793
794 a2 = (a1 >> 16) & 0xff;
795 a3 = (a1 >> 8) & 0xff;
796 a4 = a1 & 0xff;
797 a1 >>= 24;
798
799 (void) snprintf(newbuf, sizeof(newbuf), "%s %s%u,%u,%u,%u,%u,%u%s\r\n",
800 "227 Entering Passive Mode", brackets[0], a1, a2, a3, a4,
801 a5, a6, brackets[1]);
802 return (ipf_p_ftp_pasvreply(softf, fin, ip, nat, ftp, (a5 << 8 | a6),
803 newbuf, s));
804 }
805
806 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)807 ipf_p_ftp_pasvreply(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip,
808 nat_t *nat, ftpinfo_t *ftp, u_int port, char *newmsg, char *s)
809 {
810 int inc, off, nflags;
811 tcphdr_t *tcp, tcph, *tcp2;
812 ipf_main_softc_t *softc;
813 ipf_nat_softc_t *softn;
814 size_t nlen, olen;
815 #ifdef USE_INET6
816 ip6_t *ip6;
817 #endif
818 ipnat_t *ipn;
819 fr_info_t fi;
820 ftpside_t *f;
821 nat_t *nat2;
822 mb_t *m;
823
824 softc = fin->fin_main_soft;
825 softn = softc->ipf_nat_soft;
826
827 if ((ftp->ftp_pendnat != NULL) || (ftp->ftp_pendstate != NULL))
828 ipf_p_ftp_setpending(softc, ftp);
829
830 m = fin->fin_m;
831 tcp = (tcphdr_t *)fin->fin_dp;
832 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
833
834 tcp2 = &tcph;
835 inc = 0;
836
837 f = &ftp->ftp_side[1];
838 olen = s - f->ftps_rptr;
839 nlen = strlen(newmsg);
840 inc = nlen - olen;
841 if ((inc + fin->fin_plen) > 65535) {
842 DT3(ftp_PASV_error_inc, nat_t *, nat, ftpside_t *, f,
843 int, inc);
844 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
845 printf("ipf_p_ftp_pasv:inc(%d) + ip->ip_len > 65535\n",
846 inc);
847 return (0);
848 }
849
850 ipn = ipf_proxy_rule_fwd(nat);
851 if (ipn == NULL)
852 return (APR_ERR(1));
853 ipn->in_use = 0;
854
855 /*
856 * Add skeleton NAT entry for connection which will come back the
857 * other way.
858 */
859 bzero((char *)tcp2, sizeof(*tcp2));
860 bcopy((char *)fin, (char *)&fi, sizeof(fi));
861 fi.fin_flx |= FI_IGNORE;
862 fi.fin_data[0] = 0;
863 fi.fin_data[1] = port;
864 nflags = IPN_TCP|SI_W_SPORT;
865
866 fi.fin_fr = &ftppxyfr;
867 fi.fin_dp = (char *)tcp2;
868 fi.fin_out = 1 - fin->fin_out;
869 fi.fin_dlen = sizeof(*tcp2);
870 fi.fin_src6 = nat->nat_osrc6;
871 fi.fin_dst6 = nat->nat_odst6;
872 fi.fin_plen = fi.fin_hlen + sizeof(*tcp);
873 fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE;
874
875 TCP_OFF_A(tcp2, 5);
876 tcp_set_flags(tcp2, TH_SYN);
877 tcp2->th_win = htons(8192);
878 tcp2->th_dport = htons(port);
879
880 MUTEX_ENTER(&softn->ipf_nat_new);
881 #ifdef USE_INET6
882 if (nat->nat_v[0] == 6)
883 nat2 = ipf_nat6_add(&fi, ipn, &ftp->ftp_pendnat,
884 nflags, nat->nat_dir);
885 else
886 #endif
887 nat2 = ipf_nat_add(&fi, ipn, &ftp->ftp_pendnat,
888 nflags, nat->nat_dir);
889 MUTEX_EXIT(&softn->ipf_nat_new);
890
891 if (nat2 == NULL) {
892 KFREES(ipn, ipn->in_size);
893 return (APR_ERR(1));
894 }
895
896 (void) ipf_nat_proto(&fi, nat2, IPN_TCP);
897 MUTEX_ENTER(&nat2->nat_lock);
898 ipf_nat_update(&fi, nat2);
899 MUTEX_EXIT(&nat2->nat_lock);
900 fi.fin_ifp = NULL;
901 if (nat->nat_dir == NAT_INBOUND) {
902 #ifdef USE_INET6
903 if (nat->nat_v[0] == 6)
904 fi.fin_dst6 = nat->nat_ndst6;
905 else
906 #endif
907 fi.fin_daddr = nat->nat_ndstaddr;
908 }
909 if (ipf_state_add(softc, &fi, (ipstate_t **)&ftp->ftp_pendstate,
910 SI_W_SPORT) != 0)
911 ipf_nat_setpending(softc, nat2);
912
913 #if !defined(_KERNEL)
914 M_ADJ(m, inc);
915 #else
916 /*
917 * m_adj takes care of pkthdr.len, if required and treats inc<0 to
918 * mean remove -len bytes from the end of the packet.
919 * The mbuf chain will be extended if necessary by m_copyback().
920 */
921 if (inc < 0)
922 M_ADJ(m, inc);
923 #endif /* !defined(_KERNEL) */
924 COPYBACK(m, off, nlen, newmsg);
925 fin->fin_flx |= FI_DOCKSUM;
926
927 if (inc != 0) {
928 fin->fin_plen += inc;
929 fin->fin_dlen += inc;
930 #ifdef USE_INET6
931 if (nat->nat_v[0] == 6) {
932 ip6 = (ip6_t *)fin->fin_ip;
933 u_short len = ntohs(ip6->ip6_plen) + inc;
934 ip6->ip6_plen = htons(len);
935 } else
936 #endif
937 ip->ip_len = htons(fin->fin_plen);
938 }
939
940 return (APR_INC(inc));
941 }
942
943
944 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)945 ipf_p_ftp_server(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat,
946 ftpinfo_t *ftp, int dlen)
947 {
948 char *rptr, *wptr;
949 ftpside_t *f;
950 int inc;
951
952 inc = 0;
953 f = &ftp->ftp_side[1];
954 rptr = f->ftps_rptr;
955 wptr = f->ftps_wptr;
956
957 DT2(ftp_server_response, char *, rptr, int, ftp->ftp_passok);
958 if (*rptr == ' ')
959 goto server_cmd_ok;
960 if (!ISDIGIT(*rptr) || !ISDIGIT(*(rptr + 1)) || !ISDIGIT(*(rptr + 2)))
961 return (0);
962 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
963 printf("ipf_p_ftp_server_1: cmd[%4.4s] passok %d\n",
964 rptr, ftp->ftp_passok);
965 if (ftp->ftp_passok == FTPXY_GO) {
966 if (!strncmp(rptr, "227 ", 4))
967 inc = ipf_p_ftp_pasv(softf, fin, ip, nat, ftp, dlen);
968 else if (!strncmp(rptr, "229 ", 4))
969 inc = ipf_p_ftp_epsv(softf, fin, ip, nat, ftp, dlen);
970 else if (strncmp(rptr, "200", 3)) {
971 /*
972 * 200 is returned for a successful command.
973 */
974 ;
975 }
976 } else if (softf->ipf_p_ftp_insecure && !strncmp(rptr, "227 ", 4)) {
977 inc = ipf_p_ftp_pasv(softf, fin, ip, nat, ftp, dlen);
978 } else if (softf->ipf_p_ftp_insecure && !strncmp(rptr, "229 ", 4)) {
979 inc = ipf_p_ftp_epsv(softf, fin, ip, nat, ftp, dlen);
980 } else if (*rptr == '5' || *rptr == '4')
981 ftp->ftp_passok = FTPXY_INIT;
982 else if (ftp->ftp_incok) {
983 if (*rptr == '3') {
984 if (ftp->ftp_passok == FTPXY_ACCT_1)
985 ftp->ftp_passok = FTPXY_GO;
986 else
987 ftp->ftp_passok++;
988 } else if (*rptr == '2') {
989 switch (ftp->ftp_passok)
990 {
991 case FTPXY_USER_1 :
992 case FTPXY_USER_2 :
993 case FTPXY_PASS_1 :
994 case FTPXY_PASS_2 :
995 case FTPXY_ACCT_1 :
996 ftp->ftp_passok = FTPXY_GO;
997 break;
998 default :
999 ftp->ftp_passok += 3;
1000 break;
1001 }
1002 }
1003 }
1004 ftp->ftp_incok = 0;
1005 server_cmd_ok:
1006 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
1007 printf("ipf_p_ftp_server_2: cmd[%4.4s] passok %d\n",
1008 rptr, ftp->ftp_passok);
1009 DT3(ftp_server_passok, char *,rptr, int, ftp->ftp_incok,
1010 int, ftp->ftp_passok);
1011
1012 while ((*rptr++ != '\n') && (rptr < wptr))
1013 ;
1014 f->ftps_rptr = rptr;
1015 return (inc);
1016 }
1017
1018
1019 /*
1020 * 0 FTPXY_JUNK_OK
1021 * 1 FTPXY_JUNK_BAD
1022 * 2 FTPXY_JUNK_EOL
1023 * 3 FTPXY_JUNK_CONT
1024 *
1025 * Look to see if the buffer starts with something which we recognise as
1026 * being the correct syntax for the FTP protocol.
1027 */
1028 int
ipf_p_ftp_client_valid(ipf_ftp_softc_t * softf,ftpside_t * ftps,char * buf,size_t len)1029 ipf_p_ftp_client_valid(ipf_ftp_softc_t *softf, ftpside_t *ftps, char *buf,
1030 size_t len)
1031 {
1032 register char *s, c, pc;
1033 register size_t i = len;
1034 char cmd[5];
1035
1036 s = buf;
1037
1038 if (ftps->ftps_junk == FTPXY_JUNK_BAD)
1039 return (FTPXY_JUNK_BAD);
1040
1041 if (i < 5) {
1042 DT1(client_valid, int, i);
1043 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
1044 printf("ipf_p_ftp_client_valid:i(%d) < 5\n", (int)i);
1045 return (2);
1046 }
1047
1048 i--;
1049 c = *s++;
1050
1051 if (ISALPHA(c)) {
1052 cmd[0] = TOUPPER(c);
1053 c = *s++;
1054 i--;
1055 if (ISALPHA(c)) {
1056 cmd[1] = TOUPPER(c);
1057 c = *s++;
1058 i--;
1059 if (ISALPHA(c)) {
1060 cmd[2] = TOUPPER(c);
1061 c = *s++;
1062 i--;
1063 if (ISALPHA(c)) {
1064 cmd[3] = TOUPPER(c);
1065 c = *s++;
1066 i--;
1067 if ((c != ' ') && (c != '\r'))
1068 goto bad_client_command;
1069 } else if ((c != ' ') && (c != '\r'))
1070 goto bad_client_command;
1071 } else
1072 goto bad_client_command;
1073 } else
1074 goto bad_client_command;
1075 } else {
1076 bad_client_command:
1077 DT4(client_junk, int, len, int, i, int, c, char *, buf);
1078 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
1079 printf("%s:bad:junk %d len %d/%d c 0x%x buf [%*.*s]\n",
1080 "ipf_p_ftp_client_valid",
1081 ftps->ftps_junk, (int)len, (int)i, c,
1082 (int)len, (int)len, buf);
1083 return (FTPXY_JUNK_BAD);
1084 }
1085
1086 for (; i; i--) {
1087 pc = c;
1088 c = *s++;
1089 if ((pc == '\r') && (c == '\n')) {
1090 cmd[4] = '\0';
1091 if (!strcmp(cmd, "PASV")) {
1092 ftps->ftps_cmd = FTPXY_C_PASV;
1093 } else if (!strcmp(cmd, "EPSV")) {
1094 ftps->ftps_cmd = FTPXY_C_EPSV;
1095 } else {
1096 ftps->ftps_cmd = 0;
1097 }
1098 return (0);
1099 }
1100 }
1101 #if !defined(_KERNEL)
1102 printf("ipf_p_ftp_client_valid:junk after cmd[%*.*s]\n",
1103 (int)len, (int)len, buf);
1104 #endif
1105 return (FTPXY_JUNK_EOL);
1106 }
1107
1108
1109 int
ipf_p_ftp_server_valid(ipf_ftp_softc_t * softf,ftpside_t * ftps,char * buf,size_t len)1110 ipf_p_ftp_server_valid(ipf_ftp_softc_t *softf, ftpside_t *ftps, char *buf,
1111 size_t len)
1112 {
1113 register char *s, c, pc;
1114 register size_t i = len;
1115 int cmd;
1116
1117 s = buf;
1118 cmd = 0;
1119
1120 if (ftps->ftps_junk == FTPXY_JUNK_BAD)
1121 return (FTPXY_JUNK_BAD);
1122
1123 if (i < 5) {
1124 DT1(server_valid, int, i);
1125 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
1126 printf("ipf_p_ftp_servert_valid:i(%d) < 5\n", (int)i);
1127 return (2);
1128 }
1129
1130 c = *s++;
1131 i--;
1132 if (c == ' ') {
1133 cmd = -1;
1134 goto search_eol;
1135 }
1136
1137 if (ISDIGIT(c)) {
1138 cmd = (c - '0') * 100;
1139 c = *s++;
1140 i--;
1141 if (ISDIGIT(c)) {
1142 cmd += (c - '0') * 10;
1143 c = *s++;
1144 i--;
1145 if (ISDIGIT(c)) {
1146 cmd += (c - '0');
1147 c = *s++;
1148 i--;
1149 if ((c != '-') && (c != ' '))
1150 goto bad_server_command;
1151 if (c == '-')
1152 return (FTPXY_JUNK_CONT);
1153 } else
1154 goto bad_server_command;
1155 } else
1156 goto bad_server_command;
1157 } else {
1158 bad_server_command:
1159 DT4(server_junk, int len, buf, int, i, int, c, char *, buf);
1160 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_INFO)
1161 printf("%s:bad:junk %d len %d/%d c 0x%x buf [%*.*s]\n",
1162 "ipf_p_ftp_server_valid",
1163 ftps->ftps_junk, (int)len, (int)i,
1164 c, (int)len, (int)len, buf);
1165 if (ftps->ftps_junk == FTPXY_JUNK_CONT)
1166 return (FTPXY_JUNK_CONT);
1167 return (FTPXY_JUNK_BAD);
1168 }
1169 search_eol:
1170 for (; i; i--) {
1171 pc = c;
1172 c = *s++;
1173 if ((pc == '\r') && (c == '\n')) {
1174 if (cmd == -1) {
1175 if (ftps->ftps_junk == FTPXY_JUNK_CONT)
1176 return (FTPXY_JUNK_CONT);
1177 } else {
1178 ftps->ftps_cmd = cmd;
1179 }
1180 return (FTPXY_JUNK_OK);
1181 }
1182 }
1183
1184 DT2(junk_eol, int, len, char *, buf);
1185 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_INFO)
1186 printf("ipf_p_ftp_server_valid:junk after cmd[%*.*s]\n",
1187 (int)len, (int)len, buf);
1188 return (FTPXY_JUNK_EOL);
1189 }
1190
1191
1192 int
ipf_p_ftp_valid(ipf_ftp_softc_t * softf,ftpinfo_t * ftp,int side,char * buf,size_t len)1193 ipf_p_ftp_valid(ipf_ftp_softc_t *softf, ftpinfo_t *ftp, int side, char *buf,
1194 size_t len)
1195 {
1196 ftpside_t *ftps;
1197
1198 ftps = &ftp->ftp_side[side];
1199
1200 if (side == 0)
1201 return (ipf_p_ftp_client_valid(softf, ftps, buf, len));
1202 else
1203 return (ipf_p_ftp_server_valid(softf, ftps, buf, len));
1204 }
1205
1206
1207 /*
1208 * For map rules, the following applies:
1209 * rv == 0 for outbound processing,
1210 * rv == 1 for inbound processing.
1211 * For rdr rules, the following applies:
1212 * rv == 0 for inbound processing,
1213 * rv == 1 for outbound processing.
1214 */
1215 int
ipf_p_ftp_process(ipf_ftp_softc_t * softf,fr_info_t * fin,nat_t * nat,ftpinfo_t * ftp,int rv)1216 ipf_p_ftp_process(ipf_ftp_softc_t *softf, fr_info_t *fin, nat_t *nat,
1217 ftpinfo_t *ftp, int rv)
1218 {
1219 int mlen, len, off, inc, i, sel, sel2, ok, ackoff, seqoff, retry;
1220 char *rptr, *wptr, *s;
1221 u_32_t thseq, thack;
1222 ap_session_t *aps;
1223 ftpside_t *f, *t;
1224 tcphdr_t *tcp;
1225 ip_t *ip;
1226 mb_t *m;
1227
1228 m = fin->fin_m;
1229 ip = fin->fin_ip;
1230 tcp = (tcphdr_t *)fin->fin_dp;
1231 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
1232
1233 f = &ftp->ftp_side[rv];
1234 t = &ftp->ftp_side[1 - rv];
1235 thseq = ntohl(tcp->th_seq);
1236 thack = ntohl(tcp->th_ack);
1237 mlen = MSGDSIZE(m) - off;
1238
1239 DT3(process_debug, tcphdr_t *, tcp, int, off, int, mlen);
1240 if (softf->ipf_p_ftp_debug & DEBUG_INFO)
1241 printf("ipf_p_ftp_process: %d:%d,%d, mlen %d flags %x\n",
1242 fin->fin_out, fin->fin_sport, fin->fin_dport,
1243 mlen, tcp_get_flags(tcp));
1244
1245 if ((mlen == 0) && ((tcp_get_flags(tcp) & TH_OPENING) == TH_OPENING)) {
1246 f->ftps_seq[0] = thseq + 1;
1247 t->ftps_seq[0] = thack;
1248 return (0);
1249 } else if (mlen < 0) {
1250 return (0);
1251 }
1252
1253 aps = nat->nat_aps;
1254
1255 sel = aps->aps_sel[1 - rv];
1256 sel2 = aps->aps_sel[rv];
1257 if (rv == 1) {
1258 seqoff = aps->aps_seqoff[sel];
1259 if (aps->aps_seqmin[sel] > seqoff + thseq)
1260 seqoff = aps->aps_seqoff[!sel];
1261 ackoff = aps->aps_ackoff[sel2];
1262 if (aps->aps_ackmin[sel2] > ackoff + thack)
1263 ackoff = aps->aps_ackoff[!sel2];
1264 } else {
1265 seqoff = aps->aps_ackoff[sel];
1266 if (softf->ipf_p_ftp_debug & DEBUG_INFO)
1267 printf("seqoff %d thseq %x ackmin %x\n", seqoff, thseq,
1268 aps->aps_ackmin[sel]);
1269 if (aps->aps_ackmin[sel] > seqoff + thseq)
1270 seqoff = aps->aps_ackoff[!sel];
1271
1272 ackoff = aps->aps_seqoff[sel2];
1273 if (softf->ipf_p_ftp_debug & DEBUG_INFO)
1274 printf("ackoff %d thack %x seqmin %x\n", ackoff, thack,
1275 aps->aps_seqmin[sel2]);
1276 if (ackoff > 0) {
1277 if (aps->aps_seqmin[sel2] > ackoff + thack)
1278 ackoff = aps->aps_seqoff[!sel2];
1279 } else {
1280 if (aps->aps_seqmin[sel2] > thack)
1281 ackoff = aps->aps_seqoff[!sel2];
1282 }
1283 }
1284 if (softf->ipf_p_ftp_debug & DEBUG_INFO) {
1285 printf("%s: %x seq %x/%d ack %x/%d len %d/%d off %d\n",
1286 rv ? "IN" : "OUT", tcp_get_flags(tcp), thseq, seqoff,
1287 thack, ackoff, mlen, fin->fin_plen, off);
1288 printf("sel %d seqmin %x/%x offset %d/%d\n", sel,
1289 aps->aps_seqmin[sel], aps->aps_seqmin[sel2],
1290 aps->aps_seqoff[sel], aps->aps_seqoff[sel2]);
1291 printf("sel %d ackmin %x/%x offset %d/%d\n", sel2,
1292 aps->aps_ackmin[sel], aps->aps_ackmin[sel2],
1293 aps->aps_ackoff[sel], aps->aps_ackoff[sel2]);
1294 }
1295
1296 /*
1297 * XXX - Ideally, this packet should get dropped because we now know
1298 * that it is out of order (and there is no real danger in doing so
1299 * apart from causing packets to go through here ordered).
1300 */
1301 if (softf->ipf_p_ftp_debug & DEBUG_INFO) {
1302 printf("rv %d t:seq[0] %x seq[1] %x %d/%d\n",
1303 rv, t->ftps_seq[0], t->ftps_seq[1], seqoff, ackoff);
1304 }
1305
1306 ok = 0;
1307 if (t->ftps_seq[0] == 0) {
1308 t->ftps_seq[0] = thack;
1309 ok = 1;
1310 } else {
1311 if (ackoff == 0) {
1312 if (t->ftps_seq[0] == thack)
1313 ok = 1;
1314 else if (t->ftps_seq[1] == thack) {
1315 t->ftps_seq[0] = thack;
1316 ok = 1;
1317 }
1318 } else {
1319 if (t->ftps_seq[0] + ackoff == thack) {
1320 t->ftps_seq[0] = thack;
1321 ok = 1;
1322 } else if (t->ftps_seq[0] == thack + ackoff) {
1323 t->ftps_seq[0] = thack + ackoff;
1324 ok = 1;
1325 } else if (t->ftps_seq[1] + ackoff == thack) {
1326 t->ftps_seq[0] = thack;
1327 ok = 1;
1328 } else if (t->ftps_seq[1] == thack + ackoff) {
1329 t->ftps_seq[0] = thack + ackoff;
1330 ok = 1;
1331 }
1332 }
1333 }
1334
1335 if (softf->ipf_p_ftp_debug & DEBUG_INFO) {
1336 if (!ok)
1337 printf("%s ok\n", "not");
1338 }
1339
1340 if (!mlen) {
1341 if (t->ftps_seq[0] + ackoff != thack &&
1342 t->ftps_seq[1] + ackoff != thack) {
1343 DT3(thack, ftpside_t *t, t, int, ackoff, u_32_t, thack);
1344 if (softf->ipf_p_ftp_debug & DEBUG_ERROR) {
1345 printf("%s:seq[0](%u) + (%d) != (%u)\n",
1346 "ipf_p_ftp_process", t->ftps_seq[0],
1347 ackoff, thack);
1348 printf("%s:seq[1](%u) + (%d) != (%u)\n",
1349 "ipf_p_ftp_process", t->ftps_seq[1],
1350 ackoff, thack);
1351 }
1352 return (APR_ERR(1));
1353 }
1354
1355 if (softf->ipf_p_ftp_debug & DEBUG_PARSE) {
1356 printf("ipf_p_ftp_process:f:seq[0] %x seq[1] %x\n",
1357 f->ftps_seq[0], f->ftps_seq[1]);
1358 }
1359
1360 if (tcp_get_flags(tcp) & TH_FIN) {
1361 if (thseq == f->ftps_seq[1]) {
1362 f->ftps_seq[0] = f->ftps_seq[1] - seqoff;
1363 f->ftps_seq[1] = thseq + 1 - seqoff;
1364 } else {
1365 DT2(thseq, ftpside_t *t, t, u_32_t, thseq);
1366 if (softf->ipf_p_ftp_debug & DEBUG_ERROR) {
1367 printf("FIN: thseq %x seqoff %d ftps_seq %x\n",
1368 thseq, seqoff, f->ftps_seq[0]);
1369 }
1370 return (APR_ERR(1));
1371 }
1372 }
1373 f->ftps_len = 0;
1374 return (0);
1375 }
1376
1377 ok = 0;
1378 if ((thseq == f->ftps_seq[0]) || (thseq == f->ftps_seq[1])) {
1379 ok = 1;
1380 /*
1381 * Retransmitted data packet.
1382 */
1383 } else if ((thseq + mlen == f->ftps_seq[0]) ||
1384 (thseq + mlen == f->ftps_seq[1])) {
1385 ok = 1;
1386 }
1387
1388 if (ok == 0) {
1389 DT3(ok_0, ftpside_t *, f, u_32_t, thseq, int, mlen);
1390 inc = thseq - f->ftps_seq[0];
1391 if (softf->ipf_p_ftp_debug & DEBUG_ERROR) {
1392 printf("inc %d sel %d rv %d\n", inc, sel, rv);
1393 printf("th_seq %x ftps_seq %x/%x\n",
1394 thseq, f->ftps_seq[0], f->ftps_seq[1]);
1395 printf("ackmin %x ackoff %d\n", aps->aps_ackmin[sel],
1396 aps->aps_ackoff[sel]);
1397 printf("seqmin %x seqoff %d\n", aps->aps_seqmin[sel],
1398 aps->aps_seqoff[sel]);
1399 }
1400
1401 return (APR_ERR(1));
1402 }
1403
1404 inc = 0;
1405 rptr = f->ftps_rptr;
1406 wptr = f->ftps_wptr;
1407 f->ftps_seq[0] = thseq;
1408 f->ftps_seq[1] = f->ftps_seq[0] + mlen;
1409 f->ftps_len = mlen;
1410
1411 while (mlen > 0) {
1412 len = MIN(mlen, sizeof(f->ftps_buf) - (wptr - rptr));
1413 if (len == 0)
1414 break;
1415 COPYDATA(m, off, len, wptr);
1416 mlen -= len;
1417 off += len;
1418 wptr += len;
1419
1420 whilemore:
1421 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
1422 printf("%s:len %d/%d off %d wptr %lx junk %d [%*.*s]\n",
1423 "ipf_p_ftp_process",
1424 len, mlen, off, (u_long)wptr, f->ftps_junk,
1425 len, len, rptr);
1426
1427 f->ftps_wptr = wptr;
1428 if (f->ftps_junk != FTPXY_JUNK_OK) {
1429 i = f->ftps_junk;
1430 f->ftps_junk = ipf_p_ftp_valid(softf, ftp, rv, rptr,
1431 wptr - rptr);
1432 DT2(junk_transit, int, i, int, f->ftps_junk);
1433
1434 if (softf->ipf_p_ftp_debug & DEBUG_PARSE)
1435 printf("%s:junk %d -> %d\n",
1436 "ipf_p_ftp_process", i, f->ftps_junk);
1437
1438 if (f->ftps_junk == FTPXY_JUNK_BAD) {
1439 DT(buffer_full);
1440 if (wptr - rptr == sizeof(f->ftps_buf)) {
1441 if (softf->ipf_p_ftp_debug &
1442 DEBUG_PARSE_INFO)
1443 printf("%s:full buffer\n",
1444 "ipf_p_ftp_process");
1445 f->ftps_rptr = f->ftps_buf;
1446 f->ftps_wptr = f->ftps_buf;
1447 rptr = f->ftps_rptr;
1448 wptr = f->ftps_wptr;
1449 continue;
1450 }
1451 }
1452 }
1453
1454 while ((f->ftps_junk == FTPXY_JUNK_OK) && (wptr > rptr)) {
1455 len = wptr - rptr;
1456 f->ftps_junk = ipf_p_ftp_valid(softf, ftp, rv,
1457 rptr, len);
1458 DT5(junk_ftp_valid, int, len, int, rv, u_long, rptr,
1459 u_long, wptr, int, f->ftps_junk);
1460
1461 if (softf->ipf_p_ftp_debug & DEBUG_PARSE) {
1462 printf("%s=%d len %d rv %d ptr %lx/%lx ",
1463 "ipf_p_ftp_valid",
1464 f->ftps_junk, len, rv, (u_long)rptr,
1465 (u_long)wptr);
1466 printf("buf [%*.*s]\n", len, len, rptr);
1467 }
1468
1469 if (f->ftps_junk == FTPXY_JUNK_OK) {
1470 f->ftps_cmds++;
1471 f->ftps_rptr = rptr;
1472 if (rv)
1473 inc += ipf_p_ftp_server(softf, fin, ip,
1474 nat, ftp, len);
1475 else
1476 inc += ipf_p_ftp_client(softf, fin, ip,
1477 nat, ftp, len);
1478 rptr = f->ftps_rptr;
1479 wptr = f->ftps_wptr;
1480 }
1481 }
1482
1483 /*
1484 * Off to a bad start so lets just forget about using the
1485 * ftp proxy for this connection.
1486 */
1487 if ((f->ftps_cmds == 0) && (f->ftps_junk == FTPXY_JUNK_BAD)) {
1488 /* f->ftps_seq[1] += inc; */
1489
1490 DT(ftp_junk_cmd);
1491 if (softf->ipf_p_ftp_debug & DEBUG_ERROR)
1492 printf("%s:cmds == 0 junk == 1\n",
1493 "ipf_p_ftp_process");
1494 return (APR_ERR(2));
1495 }
1496
1497 retry = 0;
1498 if ((f->ftps_junk != FTPXY_JUNK_OK) && (rptr < wptr)) {
1499 for (s = rptr; s < wptr; s++) {
1500 if ((*s == '\r') && (s + 1 < wptr) &&
1501 (*(s + 1) == '\n')) {
1502 rptr = s + 2;
1503 retry = 1;
1504 if (f->ftps_junk != FTPXY_JUNK_CONT)
1505 f->ftps_junk = FTPXY_JUNK_OK;
1506 break;
1507 }
1508 }
1509 }
1510
1511 if (rptr == wptr) {
1512 rptr = wptr = f->ftps_buf;
1513 } else {
1514 /*
1515 * Compact the buffer back to the start. The junk
1516 * flag should already be set and because we're not
1517 * throwing away any data, it is preserved from its
1518 * current state.
1519 */
1520 if (rptr > f->ftps_buf) {
1521 bcopy(rptr, f->ftps_buf, wptr - rptr);
1522 wptr -= rptr - f->ftps_buf;
1523 rptr = f->ftps_buf;
1524 }
1525 }
1526 f->ftps_rptr = rptr;
1527 f->ftps_wptr = wptr;
1528 if (retry)
1529 goto whilemore;
1530 }
1531
1532 /* f->ftps_seq[1] += inc; */
1533 if (tcp_get_flags(tcp) & TH_FIN)
1534 f->ftps_seq[1]++;
1535 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_INFO) {
1536 mlen = MSGDSIZE(m);
1537 mlen -= off;
1538 printf("ftps_seq[1] = %x inc %d len %d\n",
1539 f->ftps_seq[1], inc, mlen);
1540 }
1541
1542 f->ftps_rptr = rptr;
1543 f->ftps_wptr = wptr;
1544 return (APR_INC(inc));
1545 }
1546
1547
1548 int
ipf_p_ftp_out(void * arg,fr_info_t * fin,ap_session_t * aps,nat_t * nat)1549 ipf_p_ftp_out(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat)
1550 {
1551 ipf_ftp_softc_t *softf = arg;
1552 ftpinfo_t *ftp;
1553 int rev;
1554
1555 ftp = aps->aps_data;
1556 if (ftp == NULL)
1557 return (0);
1558
1559 rev = (nat->nat_dir == NAT_OUTBOUND) ? 0 : 1;
1560 if (ftp->ftp_side[1 - rev].ftps_ifp == NULL)
1561 ftp->ftp_side[1 - rev].ftps_ifp = fin->fin_ifp;
1562
1563 return (ipf_p_ftp_process(softf, fin, nat, ftp, rev));
1564 }
1565
1566
1567 int
ipf_p_ftp_in(void * arg,fr_info_t * fin,ap_session_t * aps,nat_t * nat)1568 ipf_p_ftp_in(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat)
1569 {
1570 ipf_ftp_softc_t *softf = arg;
1571 ftpinfo_t *ftp;
1572 int rev;
1573
1574 ftp = aps->aps_data;
1575 if (ftp == NULL)
1576 return (0);
1577
1578 rev = (nat->nat_dir == NAT_OUTBOUND) ? 0 : 1;
1579 if (ftp->ftp_side[rev].ftps_ifp == NULL)
1580 ftp->ftp_side[rev].ftps_ifp = fin->fin_ifp;
1581
1582 return (ipf_p_ftp_process(softf, fin, nat, ftp, 1 - rev));
1583 }
1584
1585
1586 /*
1587 * ipf_p_ftp_atoi - implement a version of atoi which processes numbers in
1588 * pairs separated by commas (which are expected to be in the range 0 - 255),
1589 * returning a 16 bit number combining either side of the , as the MSB and
1590 * LSB.
1591 */
1592 u_short
ipf_p_ftp_atoi(char ** ptr)1593 ipf_p_ftp_atoi(char **ptr)
1594 {
1595 register char *s = *ptr, c;
1596 register u_char i = 0, j = 0;
1597
1598 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1599 i *= 10;
1600 i += c - '0';
1601 }
1602 if (c != ',') {
1603 *ptr = NULL;
1604 return (0);
1605 }
1606 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1607 j *= 10;
1608 j += c - '0';
1609 }
1610 *ptr = s;
1611 i &= 0xff;
1612 j &= 0xff;
1613 return (i << 8) | j;
1614 }
1615
1616
1617 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)1618 ipf_p_ftp_eprt(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat,
1619 ftpinfo_t *ftp, int dlen)
1620 {
1621 ftpside_t *f;
1622
1623 /*
1624 * Check for client sending out EPRT message.
1625 */
1626 if (dlen < IPF_MINEPRTLEN) {
1627 DT1(epert_dlen, int, dlen);
1628 if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR)
1629 printf("ipf_p_ftp_eprt:dlen(%d) < IPF_MINEPRTLEN\n",
1630 dlen);
1631 return (0);
1632 }
1633
1634 /*
1635 * Parse the EPRT command. Format is:
1636 * "EPRT |1|1.2.3.4|2000|" for IPv4 and
1637 * "EPRT |2|ef00::1:2|2000|" for IPv6
1638 */
1639 f = &ftp->ftp_side[0];
1640 if (f->ftps_rptr[5] != '|')
1641 return (0);
1642 if (f->ftps_rptr[5] == f->ftps_rptr[7]) {
1643 if (f->ftps_rptr[6] == '1' && nat->nat_v[0] == 4)
1644 return (ipf_p_ftp_eprt4(softf, fin, ip, nat, ftp, dlen));
1645 #ifdef USE_INET6
1646 if (f->ftps_rptr[6] == '2' && nat->nat_v[0] == 6)
1647 return (ipf_p_ftp_eprt6(softf, fin, ip, nat, ftp, dlen));
1648 #endif
1649 }
1650 return (0);
1651 }
1652
1653
1654 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)1655 ipf_p_ftp_eprt4(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat,
1656 ftpinfo_t *ftp, int dlen)
1657 {
1658 int a1, a2, a3, a4, port, olen, nlen, inc, off;
1659 char newbuf[IPF_FTPBUFSZ];
1660 char *s, c, delim;
1661 u_32_t addr, i;
1662 tcphdr_t *tcp;
1663 ftpside_t *f;
1664 mb_t *m;
1665
1666 m = fin->fin_m;
1667 tcp = (tcphdr_t *)fin->fin_dp;
1668 off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
1669 f = &ftp->ftp_side[0];
1670 delim = f->ftps_rptr[5];
1671 s = f->ftps_rptr + 8;
1672
1673 /*
1674 * get the IP address.
1675 */
1676 i = 0;
1677 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1678 i *= 10;
1679 i += c - '0';
1680 }
1681 if (i > 255)
1682 return (0);
1683 if (c != '.')
1684 return (0);
1685 addr = (i << 24);
1686
1687 i = 0;
1688 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1689 i *= 10;
1690 i += c - '0';
1691 }
1692 if (i > 255)
1693 return (0);
1694 if (c != '.')
1695 return (0);
1696 addr |= (addr << 16);
1697
1698 i = 0;
1699 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1700 i *= 10;
1701 i += c - '0';
1702 }
1703 if (i > 255)
1704 return (0);
1705 if (c != '.')
1706 return (0);
1707 addr |= (addr << 8);
1708
1709 i = 0;
1710 while (((c = *s++) != '\0') && ISDIGIT(c)) {
1711 i *= 10;
1712 i += c - '0';
1713 }
1714 if (i > 255)
1715 return (0);
1716 if (c != delim)
1717 return (0);
1718 addr |= addr;
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