1 | /* $NetBSD: ip_ftp_pxy.c,v 1.6 2016/10/16 05:11:34 mrg Exp $ */ |
2 | |
3 | /* |
4 | * Copyright (C) 2012 by Darren Reed. |
5 | * |
6 | * See the IPFILTER.LICENCE file for details on licencing. |
7 | * |
8 | * Simple FTP transparent proxy for in-kernel use. For use with the NAT |
9 | * code. |
10 | * |
11 | * Id: ip_ftp_pxy.c,v 1.1.1.2 2012/07/22 13:45:18 darrenr Exp |
12 | */ |
13 | |
14 | #include <sys/cdefs.h> |
15 | __KERNEL_RCSID(1, "$NetBSD: ip_ftp_pxy.c,v 1.6 2016/10/16 05:11:34 mrg Exp $" ); |
16 | |
17 | #define IPF_FTP_PROXY |
18 | |
19 | #define IPF_MINPORTLEN 18 |
20 | #define IPF_MINEPRTLEN 20 |
21 | #define IPF_MAXPORTLEN 30 |
22 | #define IPF_MIN227LEN 39 |
23 | #define IPF_MAX227LEN 51 |
24 | #define IPF_MIN229LEN 47 |
25 | #define IPF_MAX229LEN 51 |
26 | |
27 | #define FTPXY_GO 0 |
28 | #define FTPXY_INIT 1 |
29 | #define FTPXY_USER_1 2 |
30 | #define FTPXY_USOK_1 3 |
31 | #define FTPXY_PASS_1 4 |
32 | #define FTPXY_PAOK_1 5 |
33 | #define FTPXY_AUTH_1 6 |
34 | #define FTPXY_AUOK_1 7 |
35 | #define FTPXY_ADAT_1 8 |
36 | #define FTPXY_ADOK_1 9 |
37 | #define FTPXY_ACCT_1 10 |
38 | #define FTPXY_ACOK_1 11 |
39 | #define FTPXY_USER_2 12 |
40 | #define FTPXY_USOK_2 13 |
41 | #define FTPXY_PASS_2 14 |
42 | #define FTPXY_PAOK_2 15 |
43 | |
44 | #define FTPXY_JUNK_OK 0 |
45 | #define FTPXY_JUNK_BAD 1 /* Ignore all commands for this connection */ |
46 | #define FTPXY_JUNK_EOL 2 /* consume the rest of this line only */ |
47 | #define FTPXY_JUNK_CONT 3 /* Saerching for next numeric */ |
48 | |
49 | /* |
50 | * Values for FTP commands. Numerics cover 0-999 |
51 | */ |
52 | #define FTPXY_C_PASV 1000 |
53 | #define FTPXY_C_PORT 1001 |
54 | #define FTPXY_C_EPSV 1002 |
55 | #define FTPXY_C_EPRT 1003 |
56 | |
57 | |
58 | typedef struct ipf_ftp_softc_s { |
59 | int ipf_p_ftp_pasvonly; |
60 | /* Do not require logins before transfers */ |
61 | int ipf_p_ftp_insecure; |
62 | int ipf_p_ftp_pasvrdr; |
63 | /* PASV must be last command prior to 227 */ |
64 | int ipf_p_ftp_forcepasv; |
65 | int ipf_p_ftp_debug; |
66 | int ipf_p_ftp_single_xfer; |
67 | void *ipf_p_ftp_tune; |
68 | } ipf_ftp_softc_t; |
69 | |
70 | |
71 | void ipf_p_ftp_main_load(void); |
72 | void ipf_p_ftp_main_unload(void); |
73 | void *ipf_p_ftp_soft_create(ipf_main_softc_t *); |
74 | void ipf_p_ftp_soft_destroy(ipf_main_softc_t *, void *); |
75 | |
76 | int ipf_p_ftp_client(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *, |
77 | ftpinfo_t *, int); |
78 | int ipf_p_ftp_complete(char *, size_t); |
79 | int ipf_p_ftp_in(void *, fr_info_t *, ap_session_t *, nat_t *); |
80 | int ipf_p_ftp_new(void *, fr_info_t *, ap_session_t *, nat_t *); |
81 | void ipf_p_ftp_del(ipf_main_softc_t *, ap_session_t *); |
82 | int ipf_p_ftp_out(void *, fr_info_t *, ap_session_t *, nat_t *); |
83 | int ipf_p_ftp_pasv(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *, |
84 | ftpinfo_t *, int); |
85 | int ipf_p_ftp_epsv(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *, |
86 | ftpinfo_t *, int); |
87 | int ipf_p_ftp_port(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *, |
88 | ftpinfo_t *, int); |
89 | int ipf_p_ftp_process(ipf_ftp_softc_t *, fr_info_t *, nat_t *, |
90 | ftpinfo_t *, int); |
91 | int ipf_p_ftp_server(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *, |
92 | ftpinfo_t *, int); |
93 | int ipf_p_ftp_valid(ipf_ftp_softc_t *, ftpinfo_t *, int, char *, size_t); |
94 | int ipf_p_ftp_server_valid(ipf_ftp_softc_t *, ftpside_t *, char *, |
95 | size_t); |
96 | int ipf_p_ftp_client_valid(ipf_ftp_softc_t *, ftpside_t *, char *, |
97 | size_t); |
98 | u_short ipf_p_ftp_atoi(char **); |
99 | int ipf_p_ftp_pasvreply(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *, |
100 | ftpinfo_t *, u_int, char *, char *); |
101 | int ipf_p_ftp_eprt(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *, |
102 | ftpinfo_t *, int); |
103 | int ipf_p_ftp_eprt4(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *, |
104 | ftpinfo_t *, int); |
105 | int ipf_p_ftp_eprt6(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *, |
106 | ftpinfo_t *, int); |
107 | int ipf_p_ftp_addport(ipf_ftp_softc_t *, fr_info_t *, ip_t *, nat_t *, |
108 | ftpinfo_t *, int, int, int); |
109 | void ipf_p_ftp_setpending(ipf_main_softc_t *, ftpinfo_t *); |
110 | |
111 | /* |
112 | * Debug levels |
113 | */ |
114 | #define DEBUG_SECURITY 0x01 |
115 | #define DEBUG_ERROR 0x02 |
116 | #define DEBUG_INFO 0x04 |
117 | #define DEBUG_PARSE_ERR 0x08 |
118 | #define DEBUG_PARSE_INFO 0x10 |
119 | #define DEBUG_PARSE 0x20 |
120 | |
121 | static int ipf_p_ftp_proxy_init = 0; |
122 | static frentry_t ftppxyfr; |
123 | static ipftuneable_t ipf_ftp_tuneables[] = { |
124 | { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_debug) }, |
125 | "ftp_debug" , 0, 0x7f, |
126 | stsizeof(ipf_ftp_softc_t, ipf_p_ftp_debug), |
127 | 0, NULL, NULL }, |
128 | { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_pasvonly) }, |
129 | "ftp_pasvonly" , 0, 1, |
130 | stsizeof(ipf_ftp_softc_t, ipf_p_ftp_pasvonly), |
131 | 0, NULL, NULL }, |
132 | { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_insecure) }, |
133 | "ftp_insecure" , 0, 1, |
134 | stsizeof(ipf_ftp_softc_t, ipf_p_ftp_insecure), |
135 | 0, NULL, NULL }, |
136 | { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_pasvrdr) }, |
137 | "ftp_pasvrdr" , 0, 1, |
138 | stsizeof(ipf_ftp_softc_t, ipf_p_ftp_pasvrdr), |
139 | 0, NULL, NULL }, |
140 | { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_forcepasv) }, |
141 | "ftp_forcepasv" , 0, 1, |
142 | stsizeof(ipf_ftp_softc_t, ipf_p_ftp_forcepasv), |
143 | 0, NULL, NULL }, |
144 | { { (void *)offsetof(ipf_ftp_softc_t, ipf_p_ftp_single_xfer) }, |
145 | "ftp_single_xfer" , 0, 1, |
146 | stsizeof(ipf_ftp_softc_t, ipf_p_ftp_single_xfer), |
147 | 0, NULL, NULL }, |
148 | { { NULL }, NULL, 0, 0, 0, 0, NULL, NULL } |
149 | }; |
150 | |
151 | |
152 | void |
153 | ipf_p_ftp_main_load(void) |
154 | { |
155 | bzero((char *)&ftppxyfr, sizeof(ftppxyfr)); |
156 | ftppxyfr.fr_ref = 1; |
157 | ftppxyfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE; |
158 | |
159 | MUTEX_INIT(&ftppxyfr.fr_lock, "FTP Proxy Mutex" ); |
160 | ipf_p_ftp_proxy_init = 1; |
161 | } |
162 | |
163 | |
164 | void |
165 | ipf_p_ftp_main_unload(void) |
166 | { |
167 | |
168 | if (ipf_p_ftp_proxy_init == 1) { |
169 | MUTEX_DESTROY(&ftppxyfr.fr_lock); |
170 | ipf_p_ftp_proxy_init = 0; |
171 | } |
172 | } |
173 | |
174 | |
175 | /* |
176 | * Initialize local structures. |
177 | */ |
178 | void * |
179 | ipf_p_ftp_soft_create(ipf_main_softc_t *softc) |
180 | { |
181 | ipf_ftp_softc_t *softf; |
182 | |
183 | KMALLOC(softf, ipf_ftp_softc_t *); |
184 | if (softf == NULL) |
185 | return NULL; |
186 | |
187 | bzero((char *)softf, sizeof(*softf)); |
188 | #if defined(_KERNEL) |
189 | softf->ipf_p_ftp_debug = 0; |
190 | #else |
191 | softf->ipf_p_ftp_debug = DEBUG_PARSE_ERR; |
192 | #endif |
193 | softf->ipf_p_ftp_forcepasv = 1; |
194 | |
195 | softf->ipf_p_ftp_tune = ipf_tune_array_copy(softf, |
196 | sizeof(ipf_ftp_tuneables), |
197 | ipf_ftp_tuneables); |
198 | if (softf->ipf_p_ftp_tune == NULL) { |
199 | ipf_p_ftp_soft_destroy(softc, softf); |
200 | return NULL; |
201 | } |
202 | if (ipf_tune_array_link(softc, softf->ipf_p_ftp_tune) == -1) { |
203 | ipf_p_ftp_soft_destroy(softc, softf); |
204 | return NULL; |
205 | } |
206 | |
207 | return softf; |
208 | } |
209 | |
210 | |
211 | void |
212 | ipf_p_ftp_soft_destroy(ipf_main_softc_t *softc, void *arg) |
213 | { |
214 | ipf_ftp_softc_t *softf = arg; |
215 | |
216 | if (softf->ipf_p_ftp_tune != NULL) { |
217 | ipf_tune_array_unlink(softc, softf->ipf_p_ftp_tune); |
218 | KFREES(softf->ipf_p_ftp_tune, sizeof(ipf_ftp_tuneables)); |
219 | softf->ipf_p_ftp_tune = NULL; |
220 | } |
221 | |
222 | KFREE(softf); |
223 | } |
224 | |
225 | |
226 | int |
227 | ipf_p_ftp_new(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat) |
228 | { |
229 | ftpinfo_t *ftp; |
230 | ftpside_t *f; |
231 | |
232 | KMALLOC(ftp, ftpinfo_t *); |
233 | if (ftp == NULL) |
234 | return -1; |
235 | |
236 | nat = nat; /* LINT */ |
237 | |
238 | aps->aps_data = ftp; |
239 | aps->aps_psiz = sizeof(ftpinfo_t); |
240 | aps->aps_sport = htons(fin->fin_sport); |
241 | aps->aps_dport = htons(fin->fin_dport); |
242 | |
243 | bzero((char *)ftp, sizeof(*ftp)); |
244 | f = &ftp->ftp_side[0]; |
245 | f->ftps_rptr = f->ftps_buf; |
246 | f->ftps_wptr = f->ftps_buf; |
247 | f = &ftp->ftp_side[1]; |
248 | f->ftps_rptr = f->ftps_buf; |
249 | f->ftps_wptr = f->ftps_buf; |
250 | ftp->ftp_passok = FTPXY_INIT; |
251 | ftp->ftp_incok = 0; |
252 | return 0; |
253 | } |
254 | |
255 | |
256 | void |
257 | ipf_p_ftp_setpending(ipf_main_softc_t *softc, ftpinfo_t *ftp) |
258 | { |
259 | if (ftp->ftp_pendnat != NULL) |
260 | ipf_nat_setpending(softc, ftp->ftp_pendnat); |
261 | |
262 | if (ftp->ftp_pendstate != NULL) { |
263 | READ_ENTER(&softc->ipf_state); |
264 | ipf_state_setpending(softc, ftp->ftp_pendstate); |
265 | RWLOCK_EXIT(&softc->ipf_state); |
266 | } |
267 | } |
268 | |
269 | |
270 | void |
271 | ipf_p_ftp_del(ipf_main_softc_t *softc, ap_session_t *aps) |
272 | { |
273 | ftpinfo_t *ftp; |
274 | |
275 | ftp = aps->aps_data; |
276 | if (ftp != NULL) |
277 | ipf_p_ftp_setpending(softc, ftp); |
278 | } |
279 | |
280 | |
281 | int |
282 | ipf_p_ftp_port(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat, |
283 | ftpinfo_t *ftp, int dlen) |
284 | { |
285 | char newbuf[IPF_FTPBUFSZ], *s; |
286 | u_int a1, a2, a3, a4; |
287 | u_short a5, a6, sp; |
288 | size_t nlen, olen; |
289 | tcphdr_t *tcp; |
290 | int inc, off; |
291 | ftpside_t *f; |
292 | mb_t *m; |
293 | |
294 | m = fin->fin_m; |
295 | f = &ftp->ftp_side[0]; |
296 | tcp = (tcphdr_t *)fin->fin_dp; |
297 | off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff; |
298 | |
299 | /* |
300 | * Check for client sending out PORT message. |
301 | */ |
302 | if (dlen < IPF_MINPORTLEN) { |
303 | DT3(ftp_PORT_error_dlen, nat_t *, nat, ftpside_t *, f, |
304 | u_int, dlen); |
305 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE) |
306 | printf("ipf_p_ftp_port:dlen(%d) < IPF_MINPORTLEN\n" , |
307 | dlen); |
308 | return 0; |
309 | } |
310 | /* |
311 | * Skip the PORT command + space |
312 | */ |
313 | s = f->ftps_rptr + 5; |
314 | /* |
315 | * Pick out the address components, two at a time. |
316 | */ |
317 | a1 = ipf_p_ftp_atoi(&s); |
318 | if (s == NULL) { |
319 | DT2(ftp_PORT_error_atoi_1, 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" , 1); |
322 | return 0; |
323 | } |
324 | a2 = ipf_p_ftp_atoi(&s); |
325 | if (s == NULL) { |
326 | DT2(ftp_PORT_error_atoi_2, nat_t *, nat, ftpside_t *, f); |
327 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR) |
328 | printf("ipf_p_ftp_port:ipf_p_ftp_atoi(%d) failed\n" , 2); |
329 | return 0; |
330 | } |
331 | |
332 | /* |
333 | * Check that IP address in the PORT/PASV reply is the same as the |
334 | * sender of the command - prevents using PORT for port scanning. |
335 | */ |
336 | a1 <<= 16; |
337 | a1 |= a2; |
338 | if (((nat->nat_dir == NAT_OUTBOUND) && |
339 | (a1 != ntohl(nat->nat_osrcaddr))) || |
340 | ((nat->nat_dir == NAT_INBOUND) && |
341 | (a1 != ntohl(nat->nat_nsrcaddr)))) { |
342 | DT3(ftp_PORT_error_address, nat_t *, nat, ftpside_t *, f, |
343 | u_int, a1); |
344 | if (softf->ipf_p_ftp_debug & DEBUG_ERROR) |
345 | printf("ipf_p_ftp_port:%s != nat->nat_inip\n" , "a1" ); |
346 | return APR_ERR(1); |
347 | } |
348 | |
349 | a5 = ipf_p_ftp_atoi(&s); |
350 | if (s == NULL) { |
351 | DT2(ftp_PORT_error_atoi_3, nat_t *, nat, ftpside_t *, f); |
352 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR) |
353 | printf("ipf_p_ftp_port:ipf_p_ftp_atoi(%d) failed\n" , 3); |
354 | return 0; |
355 | } |
356 | if (*s == ')') |
357 | s++; |
358 | |
359 | /* |
360 | * check for CR-LF at the end. |
361 | */ |
362 | if (*s == '\n') |
363 | s--; |
364 | if ((*s != '\r') || (*(s + 1) != '\n')) { |
365 | DT2(ftp_PORT_error_no_crlf, nat_t *, nat, ftpside_t *, f); |
366 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR) |
367 | printf("ipf_p_ftp_port:missing %s\n" , "cr-lf" ); |
368 | return 0; |
369 | } |
370 | s += 2; |
371 | a6 = a5 & 0xff; |
372 | |
373 | /* |
374 | * Calculate the source port. Verification of > 1024 is in |
375 | * ipf_p_ftp_addport. |
376 | */ |
377 | a5 >>= 8; |
378 | a5 &= 0xff; |
379 | sp = a5 << 8 | a6; |
380 | |
381 | /* |
382 | * Calculate new address parts for PORT command |
383 | */ |
384 | if (nat->nat_dir == NAT_INBOUND) |
385 | a1 = ntohl(nat->nat_ndstaddr); |
386 | else |
387 | a1 = ntohl(ip->ip_src.s_addr); |
388 | a1 = ntohl(ip->ip_src.s_addr); |
389 | a2 = (a1 >> 16) & 0xff; |
390 | a3 = (a1 >> 8) & 0xff; |
391 | a4 = a1 & 0xff; |
392 | a1 >>= 24; |
393 | olen = s - f->ftps_rptr; |
394 | snprintf(newbuf, sizeof(newbuf), "%s %u,%u,%u,%u,%u,%u\r\n" , |
395 | "PORT" , a1, a2, a3, a4, a5, a6); |
396 | |
397 | nlen = strlen(newbuf); |
398 | inc = nlen - olen; |
399 | if ((inc + fin->fin_plen) > 65535) { |
400 | DT3(ftp_PORT_error_inc, nat_t *, nat, ftpside_t *, f, |
401 | int, inc); |
402 | if (softf->ipf_p_ftp_debug & DEBUG_ERROR) |
403 | printf("ipf_p_ftp_port:inc(%d) + ip->ip_len > 65535\n" , |
404 | inc); |
405 | return 0; |
406 | } |
407 | |
408 | #if !defined(_KERNEL) |
409 | M_ADJ(m, inc); |
410 | #else |
411 | /* |
412 | * m_adj takes care of pkthdr.len, if required and treats inc<0 to |
413 | * mean remove -len bytes from the end of the packet. |
414 | * The mbuf chain will be extended if necessary by m_copyback(). |
415 | */ |
416 | if (inc < 0) |
417 | M_ADJ(m, inc); |
418 | #endif /* !defined(_KERNEL) */ |
419 | COPYBACK(m, off, nlen, newbuf); |
420 | fin->fin_flx |= FI_DOCKSUM; |
421 | |
422 | if (inc != 0) { |
423 | fin->fin_plen += inc; |
424 | ip->ip_len = htons(fin->fin_plen); |
425 | fin->fin_dlen += inc; |
426 | } |
427 | |
428 | f->ftps_cmd = FTPXY_C_PORT; |
429 | return ipf_p_ftp_addport(softf, fin, ip, nat, ftp, dlen, sp, inc); |
430 | } |
431 | |
432 | |
433 | int |
434 | ipf_p_ftp_addport(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat, |
435 | ftpinfo_t *ftp, int dlen, int nport, int inc) |
436 | { |
437 | tcphdr_t tcph, *tcp2 = &tcph; |
438 | ipf_main_softc_t *softc; |
439 | ipf_nat_softc_t *softn; |
440 | int direction; |
441 | fr_info_t fi; |
442 | ipnat_t *ipn; |
443 | nat_t *nat2; |
444 | u_short sp; |
445 | int flags; |
446 | |
447 | softc = fin->fin_main_soft; |
448 | softn = softc->ipf_nat_soft; |
449 | |
450 | if ((ftp->ftp_pendnat != NULL) || (ftp->ftp_pendstate != NULL)) { |
451 | if (softf->ipf_p_ftp_single_xfer != 0) { |
452 | DT2(ftp_PORT_error_add_active, nat_t *, nat, |
453 | ftpinfo_t *, ftp); |
454 | if (softf->ipf_p_ftp_debug & DEBUG_ERROR) |
455 | printf("ipf_p_ftp_addport:xfer active %p/%p\n" , |
456 | ftp->ftp_pendnat, ftp->ftp_pendstate); |
457 | return 0; |
458 | } |
459 | ipf_p_ftp_setpending(softc, ftp); |
460 | } |
461 | |
462 | /* |
463 | * Add skeleton NAT entry for connection which will come back the |
464 | * other way. |
465 | */ |
466 | sp = nport; |
467 | /* |
468 | * Don't allow the PORT command to specify a port < 1024 due to |
469 | * security risks. |
470 | */ |
471 | if (sp < 1024) { |
472 | DT3(ftp_PORT_error_port, nat_t *, nat, ftpinfo_t *, ftp, |
473 | u_int, sp); |
474 | if (softf->ipf_p_ftp_debug & DEBUG_SECURITY) |
475 | printf("ipf_p_ftp_addport:sp(%d) < 1024\n" , sp); |
476 | return 0; |
477 | } |
478 | /* |
479 | * The server may not make the connection back from port 20, but |
480 | * it is the most likely so use it here to check for a conflicting |
481 | * mapping. |
482 | */ |
483 | bcopy((char *)fin, (char *)&fi, sizeof(fi)); |
484 | fi.fin_flx |= FI_IGNORE; |
485 | fi.fin_data[0] = sp; |
486 | fi.fin_data[1] = fin->fin_data[1] - 1; |
487 | fi.fin_src6 = nat->nat_ndst6; |
488 | fi.fin_dst6 = nat->nat_nsrc6; |
489 | |
490 | if (nat->nat_v[0] == 6) { |
491 | #ifndef USE_INET6 |
492 | return APR_INC(inc); |
493 | #endif |
494 | } |
495 | |
496 | /* |
497 | * Add skeleton NAT entry for connection which will come back the |
498 | * other way. |
499 | */ |
500 | #ifdef USE_INET6 |
501 | if (nat->nat_v[0] == 6) { |
502 | if (nat->nat_dir == NAT_OUTBOUND) { |
503 | nat2 = ipf_nat6_outlookup(&fi, IPN_TCP|NAT_SEARCH, |
504 | nat->nat_pr[1], |
505 | &nat->nat_osrc6.in6, |
506 | &nat->nat_odst6.in6); |
507 | } else { |
508 | nat2 = ipf_nat6_inlookup(&fi, IPN_TCP|NAT_SEARCH, |
509 | nat->nat_pr[0], |
510 | &nat->nat_odst6.in6, |
511 | &nat->nat_osrc6.in6); |
512 | } |
513 | } else |
514 | #endif |
515 | { |
516 | if (nat->nat_dir == NAT_OUTBOUND) { |
517 | nat2 = ipf_nat_outlookup(&fi, IPN_TCP|NAT_SEARCH, |
518 | nat->nat_pr[1], |
519 | nat->nat_osrcip, |
520 | nat->nat_odstip); |
521 | } else { |
522 | nat2 = ipf_nat_inlookup(&fi, IPN_TCP|NAT_SEARCH, |
523 | nat->nat_pr[0], |
524 | nat->nat_odstip, |
525 | nat->nat_osrcip); |
526 | } |
527 | } |
528 | if (nat2 != NULL) |
529 | return APR_INC(inc); |
530 | |
531 | ipn = ipf_proxy_rule_rev(nat); |
532 | if (ipn == NULL) |
533 | return APR_ERR(1); |
534 | ipn->in_use = 0; |
535 | |
536 | fi.fin_fr = &ftppxyfr; |
537 | fi.fin_dp = (char *)tcp2; |
538 | fi.fin_dlen = sizeof(*tcp2); |
539 | fi.fin_plen = fi.fin_hlen + sizeof(*tcp2); |
540 | fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE; |
541 | fi.fin_data[1] = sp; |
542 | fi.fin_data[0] = 0; |
543 | |
544 | bzero((char *)tcp2, sizeof(*tcp2)); |
545 | tcp2->th_sport = 0; |
546 | tcp2->th_dport = htons(sp); |
547 | |
548 | tcp2->th_win = htons(8192); |
549 | TCP_OFF_A(tcp2, 5); |
550 | tcp2->th_flags = TH_SYN; |
551 | |
552 | if (nat->nat_dir == NAT_INBOUND) { |
553 | fi.fin_out = 1; |
554 | direction = NAT_OUTBOUND; |
555 | } else { |
556 | fi.fin_out = 0; |
557 | direction = NAT_INBOUND; |
558 | } |
559 | flags = SI_W_SPORT|NAT_SLAVE|IPN_TCP; |
560 | |
561 | MUTEX_ENTER(&softn->ipf_nat_new); |
562 | if (nat->nat_v[0] == 6) { |
563 | #ifdef USE_INET6 |
564 | nat2 = ipf_nat6_add(&fi, ipn, &ftp->ftp_pendnat, flags, |
565 | direction); |
566 | #endif |
567 | } else { |
568 | nat2 = ipf_nat_add(&fi, ipn, &ftp->ftp_pendnat, flags, |
569 | direction); |
570 | } |
571 | MUTEX_EXIT(&softn->ipf_nat_new); |
572 | |
573 | if (nat2 == NULL) { |
574 | KFREES(ipn, ipn->in_size); |
575 | return APR_ERR(1); |
576 | } |
577 | |
578 | (void) ipf_nat_proto(&fi, nat2, IPN_TCP); |
579 | MUTEX_ENTER(&nat2->nat_lock); |
580 | ipf_nat_update(&fi, nat2); |
581 | MUTEX_EXIT(&nat2->nat_lock); |
582 | fi.fin_ifp = NULL; |
583 | if (nat2->nat_dir == NAT_INBOUND) |
584 | fi.fin_dst6 = nat->nat_osrc6; |
585 | if (ipf_state_add(softc, &fi, (ipstate_t **)&ftp->ftp_pendstate, |
586 | SI_W_SPORT) != 0) |
587 | ipf_nat_setpending(softc, nat2); |
588 | |
589 | return APR_INC(inc); |
590 | } |
591 | |
592 | |
593 | int |
594 | ipf_p_ftp_client(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat, |
595 | ftpinfo_t *ftp, int dlen) |
596 | { |
597 | char *rptr, *wptr, cmd[6], c; |
598 | ftpside_t *f; |
599 | int inc, i; |
600 | |
601 | inc = 0; |
602 | f = &ftp->ftp_side[0]; |
603 | rptr = f->ftps_rptr; |
604 | wptr = f->ftps_wptr; |
605 | |
606 | for (i = 0; (i < 5) && (i < dlen); i++) { |
607 | c = rptr[i]; |
608 | if (ISALPHA(c)) { |
609 | cmd[i] = TOUPPER(c); |
610 | } else { |
611 | cmd[i] = c; |
612 | } |
613 | } |
614 | cmd[i] = '\0'; |
615 | |
616 | ftp->ftp_incok = 0; |
617 | DT2(ftp_client_command, char [], cmd, int, ftp->ftp_passok); |
618 | if (!strncmp(cmd, "USER " , 5) || !strncmp(cmd, "XAUT " , 5)) { |
619 | if (ftp->ftp_passok == FTPXY_ADOK_1 || |
620 | ftp->ftp_passok == FTPXY_AUOK_1) { |
621 | ftp->ftp_passok = FTPXY_USER_2; |
622 | ftp->ftp_incok = 1; |
623 | } else { |
624 | ftp->ftp_passok = FTPXY_USER_1; |
625 | ftp->ftp_incok = 1; |
626 | } |
627 | } else if (!strncmp(cmd, "AUTH " , 5)) { |
628 | ftp->ftp_passok = FTPXY_AUTH_1; |
629 | ftp->ftp_incok = 1; |
630 | } else if (!strncmp(cmd, "PASS " , 5)) { |
631 | if (ftp->ftp_passok == FTPXY_USOK_1) { |
632 | ftp->ftp_passok = FTPXY_PASS_1; |
633 | ftp->ftp_incok = 1; |
634 | } else if (ftp->ftp_passok == FTPXY_USOK_2) { |
635 | ftp->ftp_passok = FTPXY_PASS_2; |
636 | ftp->ftp_incok = 1; |
637 | } |
638 | } else if ((ftp->ftp_passok == FTPXY_AUOK_1) && |
639 | !strncmp(cmd, "ADAT " , 5)) { |
640 | ftp->ftp_passok = FTPXY_ADAT_1; |
641 | ftp->ftp_incok = 1; |
642 | } else if ((ftp->ftp_passok == FTPXY_PAOK_1 || |
643 | ftp->ftp_passok == FTPXY_PAOK_2) && |
644 | !strncmp(cmd, "ACCT " , 5)) { |
645 | ftp->ftp_passok = FTPXY_ACCT_1; |
646 | ftp->ftp_incok = 1; |
647 | } else if ((ftp->ftp_passok == FTPXY_GO) && |
648 | !softf->ipf_p_ftp_pasvonly && |
649 | !strncmp(cmd, "PORT " , 5)) { |
650 | inc = ipf_p_ftp_port(softf, fin, ip, nat, ftp, dlen); |
651 | } else if ((ftp->ftp_passok == FTPXY_GO) && |
652 | !softf->ipf_p_ftp_pasvonly && |
653 | !strncmp(cmd, "EPRT " , 5)) { |
654 | inc = ipf_p_ftp_eprt(softf, fin, ip, nat, ftp, dlen); |
655 | } else if (softf->ipf_p_ftp_insecure && |
656 | !softf->ipf_p_ftp_pasvonly && |
657 | !strncmp(cmd, "PORT " , 5)) { |
658 | inc = ipf_p_ftp_port(softf, fin, ip, nat, ftp, dlen); |
659 | } |
660 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE) |
661 | printf("ipf_p_ftp_client: cmd[%s] passok %d incok %d inc %d\n" , |
662 | cmd, ftp->ftp_passok, ftp->ftp_incok, inc); |
663 | |
664 | DT2(ftp_client_passok, char *, cmd, int, ftp->ftp_passok); |
665 | while ((*rptr++ != '\n') && (rptr < wptr)) |
666 | ; |
667 | f->ftps_rptr = rptr; |
668 | return inc; |
669 | } |
670 | |
671 | |
672 | int |
673 | ipf_p_ftp_pasv(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat, |
674 | ftpinfo_t *ftp, int dlen) |
675 | { |
676 | u_int a1, a2, a3, a4, data_ip; |
677 | char newbuf[IPF_FTPBUFSZ]; |
678 | const char *brackets[2]; |
679 | u_short a5, a6; |
680 | ftpside_t *f; |
681 | char *s; |
682 | |
683 | if ((softf->ipf_p_ftp_forcepasv != 0) && |
684 | (ftp->ftp_side[0].ftps_cmd != FTPXY_C_PASV)) { |
685 | DT2(ftp_PASV_error_state, nat_t *, nat, ftpinfo_t *, ftp); |
686 | if (softf->ipf_p_ftp_debug & DEBUG_ERROR) |
687 | printf("ipf_p_ftp_pasv:ftps_cmd(%d) != FTPXY_C_PASV\n" , |
688 | ftp->ftp_side[0].ftps_cmd); |
689 | return 0; |
690 | } |
691 | |
692 | f = &ftp->ftp_side[1]; |
693 | |
694 | #define PASV_REPLEN 24 |
695 | /* |
696 | * Check for PASV reply message. |
697 | */ |
698 | if (dlen < IPF_MIN227LEN) { |
699 | DT3(ftp_PASV_error_short, nat_t *, nat, ftpinfo_t *, ftp, |
700 | int, dlen); |
701 | if (softf->ipf_p_ftp_debug & DEBUG_ERROR) |
702 | printf("ipf_p_ftp_pasv:dlen(%d) < IPF_MIN227LEN\n" , |
703 | dlen); |
704 | return 0; |
705 | } else if (strncmp(f->ftps_rptr, |
706 | "227 Entering Passive Mod" , PASV_REPLEN)) { |
707 | DT2(ftp_PASV_error_string, nat_t *, nat, ftpinfo_t *, ftp); |
708 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR) |
709 | printf("ipf_p_ftp_pasv:%d reply wrong\n" , 227); |
710 | return 0; |
711 | } |
712 | |
713 | brackets[0] = "" ; |
714 | brackets[1] = "" ; |
715 | /* |
716 | * Skip the PASV reply + space |
717 | */ |
718 | s = f->ftps_rptr + PASV_REPLEN; |
719 | while (*s && !ISDIGIT(*s)) { |
720 | if (*s == '(') { |
721 | brackets[0] = "(" ; |
722 | brackets[1] = ")" ; |
723 | } |
724 | s++; |
725 | } |
726 | |
727 | /* |
728 | * Pick out the address components, two at a time. |
729 | */ |
730 | a1 = ipf_p_ftp_atoi(&s); |
731 | if (s == NULL) { |
732 | DT2(ftp_PASV_error_atoi_1, 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" , 1); |
735 | return 0; |
736 | } |
737 | a2 = ipf_p_ftp_atoi(&s); |
738 | if (s == NULL) { |
739 | DT2(ftp_PASV_error_atoi_2, nat_t *, nat, ftpside_t *, f); |
740 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR) |
741 | printf("ipf_p_ftp_pasv:ipf_p_ftp_atoi(%d) failed\n" , 2); |
742 | return 0; |
743 | } |
744 | |
745 | /* |
746 | * check that IP address in the PASV reply is the same as the |
747 | * sender of the command - prevents using PASV for port scanning. |
748 | */ |
749 | a1 <<= 16; |
750 | a1 |= a2; |
751 | |
752 | if (((nat->nat_dir == NAT_INBOUND) && |
753 | (a1 != ntohl(nat->nat_ndstaddr))) || |
754 | ((nat->nat_dir == NAT_OUTBOUND) && |
755 | (a1 != ntohl(nat->nat_odstaddr)))) { |
756 | DT3(ftp_PASV_error_address, nat_t *, nat, ftpside_t *, f, |
757 | u_int, a1); |
758 | if (softf->ipf_p_ftp_debug & DEBUG_ERROR) |
759 | printf("ipf_p_ftp_pasv:%s != nat->nat_oip\n" , "a1" ); |
760 | return 0; |
761 | } |
762 | |
763 | a5 = ipf_p_ftp_atoi(&s); |
764 | if (s == NULL) { |
765 | DT2(ftp_PASV_error_atoi_3, nat_t *, nat, ftpside_t *, f); |
766 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR) |
767 | printf("ipf_p_ftp_pasv:ipf_p_ftp_atoi(%d) failed\n" , 3); |
768 | return 0; |
769 | } |
770 | |
771 | if (*s == ')') |
772 | s++; |
773 | if (*s == '.') |
774 | s++; |
775 | if (*s == '\n') |
776 | s--; |
777 | /* |
778 | * check for CR-LF at the end. |
779 | */ |
780 | if ((*s != '\r') || (*(s + 1) != '\n')) { |
781 | DT(pasv_missing_crlf); |
782 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR) |
783 | printf("ipf_p_ftp_pasv:missing %s" , "cr-lf\n" ); |
784 | return 0; |
785 | } |
786 | s += 2; |
787 | |
788 | a6 = a5 & 0xff; |
789 | a5 >>= 8; |
790 | /* |
791 | * Calculate new address parts for 227 reply |
792 | */ |
793 | if (nat->nat_dir == NAT_INBOUND) { |
794 | data_ip = nat->nat_odstaddr; |
795 | a1 = ntohl(data_ip); |
796 | } else |
797 | data_ip = htonl(a1); |
798 | |
799 | a2 = (a1 >> 16) & 0xff; |
800 | a3 = (a1 >> 8) & 0xff; |
801 | a4 = a1 & 0xff; |
802 | a1 >>= 24; |
803 | |
804 | snprintf(newbuf, sizeof(newbuf), "%s %s%u,%u,%u,%u,%u,%u%s\r\n" , |
805 | "227 Entering Passive Mode" , brackets[0], a1, a2, a3, a4, |
806 | a5, a6, brackets[1]); |
807 | return ipf_p_ftp_pasvreply(softf, fin, ip, nat, ftp, (a5 << 8 | a6), |
808 | newbuf, s); |
809 | } |
810 | |
811 | int |
812 | ipf_p_ftp_pasvreply(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, |
813 | nat_t *nat, ftpinfo_t *ftp, u_int port, char *newmsg, char *s) |
814 | { |
815 | int inc, off, nflags; |
816 | tcphdr_t *tcp, tcph, *tcp2; |
817 | ipf_main_softc_t *softc; |
818 | ipf_nat_softc_t *softn; |
819 | size_t nlen, olen; |
820 | #ifdef USE_INET6 |
821 | ip6_t *ip6; |
822 | #endif |
823 | ipnat_t *ipn; |
824 | fr_info_t fi; |
825 | ftpside_t *f; |
826 | nat_t *nat2 = NULL; |
827 | mb_t *m; |
828 | |
829 | softc = fin->fin_main_soft; |
830 | softn = softc->ipf_nat_soft; |
831 | |
832 | if ((ftp->ftp_pendnat != NULL) || (ftp->ftp_pendstate != NULL)) |
833 | ipf_p_ftp_setpending(softc, ftp); |
834 | |
835 | m = fin->fin_m; |
836 | tcp = (tcphdr_t *)fin->fin_dp; |
837 | off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff; |
838 | |
839 | tcp2 = &tcph; |
840 | inc = 0; |
841 | |
842 | f = &ftp->ftp_side[1]; |
843 | olen = s - f->ftps_rptr; |
844 | nlen = strlen(newmsg); |
845 | inc = nlen - olen; |
846 | if ((inc + fin->fin_plen) > 65535) { |
847 | DT3(ftp_PASV_error_inc, nat_t *, nat, ftpside_t *, f, |
848 | int, inc); |
849 | if (softf->ipf_p_ftp_debug & DEBUG_ERROR) |
850 | printf("ipf_p_ftp_pasv:inc(%d) + ip->ip_len > 65535\n" , |
851 | inc); |
852 | return 0; |
853 | } |
854 | |
855 | ipn = ipf_proxy_rule_fwd(nat); |
856 | if (ipn == NULL) |
857 | return APR_ERR(1); |
858 | ipn->in_use = 0; |
859 | |
860 | /* |
861 | * Add skeleton NAT entry for connection which will come back the |
862 | * other way. |
863 | */ |
864 | bzero((char *)tcp2, sizeof(*tcp2)); |
865 | bcopy((char *)fin, (char *)&fi, sizeof(fi)); |
866 | fi.fin_flx |= FI_IGNORE; |
867 | fi.fin_data[0] = 0; |
868 | fi.fin_data[1] = port; |
869 | nflags = IPN_TCP|SI_W_SPORT; |
870 | |
871 | fi.fin_fr = &ftppxyfr; |
872 | fi.fin_dp = (char *)tcp2; |
873 | fi.fin_out = 1 - fin->fin_out; |
874 | fi.fin_dlen = sizeof(*tcp2); |
875 | fi.fin_src6 = nat->nat_osrc6; |
876 | fi.fin_dst6 = nat->nat_odst6; |
877 | fi.fin_plen = fi.fin_hlen + sizeof(*tcp); |
878 | fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE; |
879 | |
880 | TCP_OFF_A(tcp2, 5); |
881 | tcp2->th_flags = TH_SYN; |
882 | tcp2->th_win = htons(8192); |
883 | tcp2->th_dport = htons(port); |
884 | |
885 | MUTEX_ENTER(&softn->ipf_nat_new); |
886 | if (nat->nat_v[0] == 6) { |
887 | #ifdef USE_INET6 |
888 | nat2 = ipf_nat6_add(&fi, ipn, &ftp->ftp_pendnat, |
889 | nflags, nat->nat_dir); |
890 | #endif |
891 | } else { |
892 | nat2 = ipf_nat_add(&fi, ipn, &ftp->ftp_pendnat, |
893 | nflags, nat->nat_dir); |
894 | } |
895 | MUTEX_EXIT(&softn->ipf_nat_new); |
896 | |
897 | if (nat2 == NULL) { |
898 | KFREES(ipn, ipn->in_size); |
899 | return APR_ERR(1); |
900 | } |
901 | |
902 | (void) ipf_nat_proto(&fi, nat2, IPN_TCP); |
903 | MUTEX_ENTER(&nat2->nat_lock); |
904 | ipf_nat_update(&fi, nat2); |
905 | MUTEX_EXIT(&nat2->nat_lock); |
906 | fi.fin_ifp = NULL; |
907 | if (nat->nat_dir == NAT_INBOUND) { |
908 | if (nat->nat_v[0] == 6) { |
909 | #ifdef USE_INET6 |
910 | fi.fin_dst6 = nat->nat_ndst6; |
911 | #endif |
912 | } else { |
913 | fi.fin_daddr = nat->nat_ndstaddr; |
914 | } |
915 | } |
916 | if (ipf_state_add(softc, &fi, (ipstate_t **)&ftp->ftp_pendstate, |
917 | SI_W_SPORT) != 0) |
918 | ipf_nat_setpending(softc, nat2); |
919 | |
920 | #if !defined(_KERNEL) |
921 | M_ADJ(m, inc); |
922 | #else |
923 | /* |
924 | * m_adj takes care of pkthdr.len, if required and treats inc<0 to |
925 | * mean remove -len bytes from the end of the packet. |
926 | * The mbuf chain will be extended if necessary by m_copyback(). |
927 | */ |
928 | if (inc < 0) |
929 | M_ADJ(m, inc); |
930 | #endif /* !defined(_KERNEL) */ |
931 | COPYBACK(m, off, nlen, newmsg); |
932 | fin->fin_flx |= FI_DOCKSUM; |
933 | |
934 | if (inc != 0) { |
935 | fin->fin_plen += inc; |
936 | fin->fin_dlen += inc; |
937 | if (nat->nat_v[0] == 6) { |
938 | #ifdef USE_INET6 |
939 | ip6 = (ip6_t *)fin->fin_ip; |
940 | u_short len = ntohs(ip6->ip6_plen) + inc; |
941 | ip6->ip6_plen = htons(len); |
942 | #endif |
943 | } else { |
944 | ip->ip_len = htons(fin->fin_plen); |
945 | } |
946 | } |
947 | |
948 | return APR_INC(inc); |
949 | } |
950 | |
951 | |
952 | int |
953 | ipf_p_ftp_server(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat, |
954 | ftpinfo_t *ftp, int dlen) |
955 | { |
956 | char *rptr, *wptr; |
957 | ftpside_t *f; |
958 | int inc; |
959 | |
960 | inc = 0; |
961 | f = &ftp->ftp_side[1]; |
962 | rptr = f->ftps_rptr; |
963 | wptr = f->ftps_wptr; |
964 | |
965 | DT2(ftp_server_response, char *, rptr, int, ftp->ftp_passok); |
966 | if (*rptr == ' ') |
967 | goto server_cmd_ok; |
968 | if (!ISDIGIT(*rptr) || !ISDIGIT(*(rptr + 1)) || !ISDIGIT(*(rptr + 2))) |
969 | return 0; |
970 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE) |
971 | printf("ipf_p_ftp_server_1: cmd[%4.4s] passok %d\n" , |
972 | rptr, ftp->ftp_passok); |
973 | if (ftp->ftp_passok == FTPXY_GO) { |
974 | if (!strncmp(rptr, "227 " , 4)) |
975 | inc = ipf_p_ftp_pasv(softf, fin, ip, nat, ftp, dlen); |
976 | else if (!strncmp(rptr, "229 " , 4)) |
977 | inc = ipf_p_ftp_epsv(softf, fin, ip, nat, ftp, dlen); |
978 | else if (strncmp(rptr, "200" , 3)) { |
979 | /* |
980 | * 200 is returned for a successful command. |
981 | */ |
982 | ; |
983 | } |
984 | } else if (softf->ipf_p_ftp_insecure && !strncmp(rptr, "227 " , 4)) { |
985 | inc = ipf_p_ftp_pasv(softf, fin, ip, nat, ftp, dlen); |
986 | } else if (softf->ipf_p_ftp_insecure && !strncmp(rptr, "229 " , 4)) { |
987 | inc = ipf_p_ftp_epsv(softf, fin, ip, nat, ftp, dlen); |
988 | } else if (*rptr == '5' || *rptr == '4') |
989 | ftp->ftp_passok = FTPXY_INIT; |
990 | else if (ftp->ftp_incok) { |
991 | if (*rptr == '3') { |
992 | if (ftp->ftp_passok == FTPXY_ACCT_1) |
993 | ftp->ftp_passok = FTPXY_GO; |
994 | else |
995 | ftp->ftp_passok++; |
996 | } else if (*rptr == '2') { |
997 | switch (ftp->ftp_passok) |
998 | { |
999 | case FTPXY_USER_1 : |
1000 | case FTPXY_USER_2 : |
1001 | case FTPXY_PASS_1 : |
1002 | case FTPXY_PASS_2 : |
1003 | case FTPXY_ACCT_1 : |
1004 | ftp->ftp_passok = FTPXY_GO; |
1005 | break; |
1006 | default : |
1007 | ftp->ftp_passok += 3; |
1008 | break; |
1009 | } |
1010 | } |
1011 | } |
1012 | ftp->ftp_incok = 0; |
1013 | server_cmd_ok: |
1014 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE) |
1015 | printf("ipf_p_ftp_server_2: cmd[%4.4s] passok %d\n" , |
1016 | rptr, ftp->ftp_passok); |
1017 | DT3(ftp_server_passok, char *,rptr, int, ftp->ftp_incok, |
1018 | int, ftp->ftp_passok); |
1019 | |
1020 | while ((*rptr++ != '\n') && (rptr < wptr)) |
1021 | ; |
1022 | f->ftps_rptr = rptr; |
1023 | return inc; |
1024 | } |
1025 | |
1026 | |
1027 | /* |
1028 | * 0 FTPXY_JUNK_OK |
1029 | * 1 FTPXY_JUNK_BAD |
1030 | * 2 FTPXY_JUNK_EOL |
1031 | * 3 FTPXY_JUNK_CONT |
1032 | * |
1033 | * Look to see if the buffer starts with something which we recognise as |
1034 | * being the correct syntax for the FTP protocol. |
1035 | */ |
1036 | int |
1037 | ipf_p_ftp_client_valid(ipf_ftp_softc_t *softf, ftpside_t *ftps, char *buf, |
1038 | size_t len) |
1039 | { |
1040 | register char *s, c, pc; |
1041 | register size_t i = len; |
1042 | char cmd[5]; |
1043 | |
1044 | s = buf; |
1045 | |
1046 | if (ftps->ftps_junk == FTPXY_JUNK_BAD) |
1047 | return FTPXY_JUNK_BAD; |
1048 | |
1049 | if (i < 5) { |
1050 | DT1(client_valid, int, i); |
1051 | if (softf->ipf_p_ftp_debug & DEBUG_ERROR) |
1052 | printf("ipf_p_ftp_client_valid:i(%d) < 5\n" , (int)i); |
1053 | return 2; |
1054 | } |
1055 | |
1056 | i--; |
1057 | c = *s++; |
1058 | |
1059 | if (ISALPHA(c)) { |
1060 | cmd[0] = TOUPPER(c); |
1061 | c = *s++; |
1062 | i--; |
1063 | if (ISALPHA(c)) { |
1064 | cmd[1] = TOUPPER(c); |
1065 | c = *s++; |
1066 | i--; |
1067 | if (ISALPHA(c)) { |
1068 | cmd[2] = TOUPPER(c); |
1069 | c = *s++; |
1070 | i--; |
1071 | if (ISALPHA(c)) { |
1072 | cmd[3] = TOUPPER(c); |
1073 | c = *s++; |
1074 | i--; |
1075 | if ((c != ' ') && (c != '\r')) |
1076 | goto bad_client_command; |
1077 | } else if ((c != ' ') && (c != '\r')) |
1078 | goto bad_client_command; |
1079 | } else |
1080 | goto bad_client_command; |
1081 | } else |
1082 | goto bad_client_command; |
1083 | } else { |
1084 | bad_client_command: |
1085 | DT4(client_junk, int, len, int, i, int, c, char *, buf); |
1086 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR) |
1087 | printf("%s:bad:junk %d len %d/%d c 0x%x buf [%*.*s]\n" , |
1088 | "ipf_p_ftp_client_valid" , |
1089 | ftps->ftps_junk, (int)len, (int)i, c, |
1090 | (int)len, (int)len, buf); |
1091 | return FTPXY_JUNK_BAD; |
1092 | } |
1093 | |
1094 | for (; i; i--) { |
1095 | pc = c; |
1096 | c = *s++; |
1097 | if ((pc == '\r') && (c == '\n')) { |
1098 | cmd[4] = '\0'; |
1099 | if (!strcmp(cmd, "PASV" )) { |
1100 | ftps->ftps_cmd = FTPXY_C_PASV; |
1101 | } else if (!strcmp(cmd, "EPSV" )) { |
1102 | ftps->ftps_cmd = FTPXY_C_EPSV; |
1103 | } else { |
1104 | ftps->ftps_cmd = 0; |
1105 | } |
1106 | return 0; |
1107 | } |
1108 | } |
1109 | #if !defined(_KERNEL) |
1110 | printf("ipf_p_ftp_client_valid:junk after cmd[%*.*s]\n" , |
1111 | (int)len, (int)len, buf); |
1112 | #endif |
1113 | return FTPXY_JUNK_EOL; |
1114 | } |
1115 | |
1116 | |
1117 | int |
1118 | ipf_p_ftp_server_valid(ipf_ftp_softc_t *softf, ftpside_t *ftps, char *buf, |
1119 | size_t len) |
1120 | { |
1121 | register char *s, c, pc; |
1122 | register size_t i = len; |
1123 | int cmd; |
1124 | |
1125 | s = buf; |
1126 | cmd = 0; |
1127 | |
1128 | if (ftps->ftps_junk == FTPXY_JUNK_BAD) |
1129 | return FTPXY_JUNK_BAD; |
1130 | |
1131 | if (i < 5) { |
1132 | DT1(server_valid, int, i); |
1133 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR) |
1134 | printf("ipf_p_ftp_servert_valid:i(%d) < 5\n" , (int)i); |
1135 | return 2; |
1136 | } |
1137 | |
1138 | c = *s++; |
1139 | i--; |
1140 | if (c == ' ') { |
1141 | cmd = -1; |
1142 | goto search_eol; |
1143 | } |
1144 | |
1145 | if (ISDIGIT(c)) { |
1146 | cmd = (c - '0') * 100; |
1147 | c = *s++; |
1148 | i--; |
1149 | if (ISDIGIT(c)) { |
1150 | cmd += (c - '0') * 10; |
1151 | c = *s++; |
1152 | i--; |
1153 | if (ISDIGIT(c)) { |
1154 | cmd += (c - '0'); |
1155 | c = *s++; |
1156 | i--; |
1157 | if ((c != '-') && (c != ' ')) |
1158 | goto bad_server_command; |
1159 | if (c == '-') |
1160 | return FTPXY_JUNK_CONT; |
1161 | } else |
1162 | goto bad_server_command; |
1163 | } else |
1164 | goto bad_server_command; |
1165 | } else { |
1166 | bad_server_command: |
1167 | DT4(server_junk, int len, buf, int, i, int, c, char *, buf); |
1168 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_INFO) |
1169 | printf("%s:bad:junk %d len %d/%d c 0x%x buf [%*.*s]\n" , |
1170 | "ipf_p_ftp_server_valid" , |
1171 | ftps->ftps_junk, (int)len, (int)i, |
1172 | c, (int)len, (int)len, buf); |
1173 | if (ftps->ftps_junk == FTPXY_JUNK_CONT) |
1174 | return FTPXY_JUNK_CONT; |
1175 | return FTPXY_JUNK_BAD; |
1176 | } |
1177 | search_eol: |
1178 | for (; i; i--) { |
1179 | pc = c; |
1180 | c = *s++; |
1181 | if ((pc == '\r') && (c == '\n')) { |
1182 | if (cmd == -1) { |
1183 | if (ftps->ftps_junk == FTPXY_JUNK_CONT) |
1184 | return FTPXY_JUNK_CONT; |
1185 | } else { |
1186 | ftps->ftps_cmd = cmd; |
1187 | } |
1188 | return FTPXY_JUNK_OK; |
1189 | } |
1190 | } |
1191 | |
1192 | DT2(junk_eol, int, len, char *, buf); |
1193 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_INFO) |
1194 | printf("ipf_p_ftp_server_valid:junk after cmd[%*.*s]\n" , |
1195 | (int)len, (int)len, buf); |
1196 | return FTPXY_JUNK_EOL; |
1197 | } |
1198 | |
1199 | |
1200 | int |
1201 | ipf_p_ftp_valid(ipf_ftp_softc_t *softf, ftpinfo_t *ftp, int side, char *buf, |
1202 | size_t len) |
1203 | { |
1204 | ftpside_t *ftps; |
1205 | int ret; |
1206 | |
1207 | ftps = &ftp->ftp_side[side]; |
1208 | |
1209 | if (side == 0) |
1210 | ret = ipf_p_ftp_client_valid(softf, ftps, buf, len); |
1211 | else |
1212 | ret = ipf_p_ftp_server_valid(softf, ftps, buf, len); |
1213 | return ret; |
1214 | } |
1215 | |
1216 | |
1217 | /* |
1218 | * For map rules, the following applies: |
1219 | * rv == 0 for outbound processing, |
1220 | * rv == 1 for inbound processing. |
1221 | * For rdr rules, the following applies: |
1222 | * rv == 0 for inbound processing, |
1223 | * rv == 1 for outbound processing. |
1224 | */ |
1225 | int |
1226 | ipf_p_ftp_process(ipf_ftp_softc_t *softf, fr_info_t *fin, nat_t *nat, |
1227 | ftpinfo_t *ftp, int rv) |
1228 | { |
1229 | int mlen, len, off, inc, i, sel, sel2, ok, ackoff, seqoff, retry; |
1230 | char *rptr, *wptr, *s; |
1231 | u_32_t thseq, thack; |
1232 | ap_session_t *aps; |
1233 | ftpside_t *f, *t; |
1234 | tcphdr_t *tcp; |
1235 | ip_t *ip; |
1236 | mb_t *m; |
1237 | |
1238 | m = fin->fin_m; |
1239 | ip = fin->fin_ip; |
1240 | tcp = (tcphdr_t *)fin->fin_dp; |
1241 | off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff; |
1242 | |
1243 | f = &ftp->ftp_side[rv]; |
1244 | t = &ftp->ftp_side[1 - rv]; |
1245 | thseq = ntohl(tcp->th_seq); |
1246 | thack = ntohl(tcp->th_ack); |
1247 | #ifdef __sgi |
1248 | mlen = fin->fin_plen - off; |
1249 | #else |
1250 | mlen = MSGDSIZE(m) - off; |
1251 | #endif |
1252 | |
1253 | DT3(process_debug, tcphdr_t *, tcp, int, off, int, mlen); |
1254 | if (softf->ipf_p_ftp_debug & DEBUG_INFO) |
1255 | printf("ipf_p_ftp_process: %d:%d,%d, mlen %d flags %x\n" , |
1256 | fin->fin_out, fin->fin_sport, fin->fin_dport, |
1257 | mlen, tcp->th_flags); |
1258 | |
1259 | if ((mlen == 0) && ((tcp->th_flags & TH_OPENING) == TH_OPENING)) { |
1260 | f->ftps_seq[0] = thseq + 1; |
1261 | t->ftps_seq[0] = thack; |
1262 | return 0; |
1263 | } else if (mlen < 0) { |
1264 | return 0; |
1265 | } |
1266 | |
1267 | aps = nat->nat_aps; |
1268 | |
1269 | sel = aps->aps_sel[1 - rv]; |
1270 | sel2 = aps->aps_sel[rv]; |
1271 | if (rv == 1) { |
1272 | seqoff = aps->aps_seqoff[sel]; |
1273 | if (aps->aps_seqmin[sel] > seqoff + thseq) |
1274 | seqoff = aps->aps_seqoff[!sel]; |
1275 | ackoff = aps->aps_ackoff[sel2]; |
1276 | if (aps->aps_ackmin[sel2] > ackoff + thack) |
1277 | ackoff = aps->aps_ackoff[!sel2]; |
1278 | } else { |
1279 | seqoff = aps->aps_ackoff[sel]; |
1280 | if (softf->ipf_p_ftp_debug & DEBUG_INFO) |
1281 | printf("seqoff %d thseq %x ackmin %x\n" , seqoff, thseq, |
1282 | aps->aps_ackmin[sel]); |
1283 | if (aps->aps_ackmin[sel] > seqoff + thseq) |
1284 | seqoff = aps->aps_ackoff[!sel]; |
1285 | |
1286 | ackoff = aps->aps_seqoff[sel2]; |
1287 | if (softf->ipf_p_ftp_debug & DEBUG_INFO) |
1288 | printf("ackoff %d thack %x seqmin %x\n" , ackoff, thack, |
1289 | aps->aps_seqmin[sel2]); |
1290 | if (ackoff > 0) { |
1291 | if (aps->aps_seqmin[sel2] > ackoff + thack) |
1292 | ackoff = aps->aps_seqoff[!sel2]; |
1293 | } else { |
1294 | if (aps->aps_seqmin[sel2] > thack) |
1295 | ackoff = aps->aps_seqoff[!sel2]; |
1296 | } |
1297 | } |
1298 | if (softf->ipf_p_ftp_debug & DEBUG_INFO) { |
1299 | printf("%s: %x seq %x/%d ack %x/%d len %d/%d off %d\n" , |
1300 | rv ? "IN" : "OUT" , tcp->th_flags, thseq, seqoff, |
1301 | thack, ackoff, mlen, fin->fin_plen, off); |
1302 | printf("sel %d seqmin %x/%x offset %d/%d\n" , sel, |
1303 | aps->aps_seqmin[sel], aps->aps_seqmin[sel2], |
1304 | aps->aps_seqoff[sel], aps->aps_seqoff[sel2]); |
1305 | printf("sel %d ackmin %x/%x offset %d/%d\n" , sel2, |
1306 | aps->aps_ackmin[sel], aps->aps_ackmin[sel2], |
1307 | aps->aps_ackoff[sel], aps->aps_ackoff[sel2]); |
1308 | } |
1309 | |
1310 | /* |
1311 | * XXX - Ideally, this packet should get dropped because we now know |
1312 | * that it is out of order (and there is no real danger in doing so |
1313 | * apart from causing packets to go through here ordered). |
1314 | */ |
1315 | if (softf->ipf_p_ftp_debug & DEBUG_INFO) { |
1316 | printf("rv %d t:seq[0] %x seq[1] %x %d/%d\n" , |
1317 | rv, t->ftps_seq[0], t->ftps_seq[1], seqoff, ackoff); |
1318 | } |
1319 | |
1320 | ok = 0; |
1321 | if (t->ftps_seq[0] == 0) { |
1322 | t->ftps_seq[0] = thack; |
1323 | ok = 1; |
1324 | } else { |
1325 | if (ackoff == 0) { |
1326 | if (t->ftps_seq[0] == thack) |
1327 | ok = 1; |
1328 | else if (t->ftps_seq[1] == thack) { |
1329 | t->ftps_seq[0] = thack; |
1330 | ok = 1; |
1331 | } |
1332 | } else { |
1333 | if (t->ftps_seq[0] + ackoff == thack) { |
1334 | t->ftps_seq[0] = thack; |
1335 | ok = 1; |
1336 | } else if (t->ftps_seq[0] == thack + ackoff) { |
1337 | t->ftps_seq[0] = thack + ackoff; |
1338 | ok = 1; |
1339 | } else if (t->ftps_seq[1] + ackoff == thack) { |
1340 | t->ftps_seq[0] = thack; |
1341 | ok = 1; |
1342 | } else if (t->ftps_seq[1] == thack + ackoff) { |
1343 | t->ftps_seq[0] = thack + ackoff; |
1344 | ok = 1; |
1345 | } |
1346 | } |
1347 | } |
1348 | |
1349 | if (softf->ipf_p_ftp_debug & DEBUG_INFO) { |
1350 | if (!ok) |
1351 | printf("%s ok\n" , "not" ); |
1352 | } |
1353 | |
1354 | if (!mlen) { |
1355 | if (t->ftps_seq[0] + ackoff != thack && |
1356 | t->ftps_seq[1] + ackoff != thack) { |
1357 | DT3(thack, ftpside_t *t, t, int, ackoff, u_32_t, thack); |
1358 | if (softf->ipf_p_ftp_debug & DEBUG_ERROR) { |
1359 | printf("%s:seq[0](%u) + (%d) != (%u)\n" , |
1360 | "ipf_p_ftp_process" , t->ftps_seq[0], |
1361 | ackoff, thack); |
1362 | printf("%s:seq[0](%u) + (%d) != (%u)\n" , |
1363 | "ipf_p_ftp_process" , t->ftps_seq[1], |
1364 | ackoff, thack); |
1365 | } |
1366 | return APR_ERR(1); |
1367 | } |
1368 | |
1369 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE) { |
1370 | printf("ipf_p_ftp_process:f:seq[0] %x seq[1] %x\n" , |
1371 | f->ftps_seq[0], f->ftps_seq[1]); |
1372 | } |
1373 | |
1374 | if (tcp->th_flags & TH_FIN) { |
1375 | if (thseq == f->ftps_seq[1]) { |
1376 | f->ftps_seq[0] = f->ftps_seq[1] - seqoff; |
1377 | f->ftps_seq[1] = thseq + 1 - seqoff; |
1378 | } else { |
1379 | DT2(thseq, ftpside_t *t, t, u_32_t, thseq); |
1380 | if (softf->ipf_p_ftp_debug & DEBUG_ERROR) { |
1381 | printf("FIN: thseq %x seqoff %d ftps_seq %x\n" , |
1382 | thseq, seqoff, f->ftps_seq[0]); |
1383 | } |
1384 | return APR_ERR(1); |
1385 | } |
1386 | } |
1387 | f->ftps_len = 0; |
1388 | return 0; |
1389 | } |
1390 | |
1391 | ok = 0; |
1392 | if ((thseq == f->ftps_seq[0]) || (thseq == f->ftps_seq[1])) { |
1393 | ok = 1; |
1394 | /* |
1395 | * Retransmitted data packet. |
1396 | */ |
1397 | } else if ((thseq + mlen == f->ftps_seq[0]) || |
1398 | (thseq + mlen == f->ftps_seq[1])) { |
1399 | ok = 1; |
1400 | } |
1401 | |
1402 | if (ok == 0) { |
1403 | DT3(ok_0, ftpside_t *, f, u_32_t, thseq, int, mlen); |
1404 | inc = thseq - f->ftps_seq[0]; |
1405 | if (softf->ipf_p_ftp_debug & DEBUG_ERROR) { |
1406 | printf("inc %d sel %d rv %d\n" , inc, sel, rv); |
1407 | printf("th_seq %x ftps_seq %x/%x\n" , |
1408 | thseq, f->ftps_seq[0], f->ftps_seq[1]); |
1409 | printf("ackmin %x ackoff %d\n" , aps->aps_ackmin[sel], |
1410 | aps->aps_ackoff[sel]); |
1411 | printf("seqmin %x seqoff %d\n" , aps->aps_seqmin[sel], |
1412 | aps->aps_seqoff[sel]); |
1413 | } |
1414 | |
1415 | return APR_ERR(1); |
1416 | } |
1417 | |
1418 | inc = 0; |
1419 | rptr = f->ftps_rptr; |
1420 | wptr = f->ftps_wptr; |
1421 | f->ftps_seq[0] = thseq; |
1422 | f->ftps_seq[1] = f->ftps_seq[0] + mlen; |
1423 | f->ftps_len = mlen; |
1424 | |
1425 | while (mlen > 0) { |
1426 | len = MIN(mlen, sizeof(f->ftps_buf) - (wptr - rptr)); |
1427 | if (len == 0) |
1428 | break; |
1429 | COPYDATA(m, off, len, wptr); |
1430 | mlen -= len; |
1431 | off += len; |
1432 | wptr += len; |
1433 | |
1434 | whilemore: |
1435 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE) |
1436 | printf("%s:len %d/%d off %d wptr %lx junk %d [%*.*s]\n" , |
1437 | "ipf_p_ftp_process" , |
1438 | len, mlen, off, (u_long)wptr, f->ftps_junk, |
1439 | len, len, rptr); |
1440 | |
1441 | f->ftps_wptr = wptr; |
1442 | if (f->ftps_junk != FTPXY_JUNK_OK) { |
1443 | i = f->ftps_junk; |
1444 | f->ftps_junk = ipf_p_ftp_valid(softf, ftp, rv, rptr, |
1445 | wptr - rptr); |
1446 | DT2(junk_transit, int, i, int, f->ftps_junk); |
1447 | |
1448 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE) |
1449 | printf("%s:junk %d -> %d\n" , |
1450 | "ipf_p_ftp_process" , i, f->ftps_junk); |
1451 | |
1452 | if (f->ftps_junk == FTPXY_JUNK_BAD) { |
1453 | DT(buffer_full); |
1454 | if (wptr - rptr == sizeof(f->ftps_buf)) { |
1455 | if (softf->ipf_p_ftp_debug & |
1456 | DEBUG_PARSE_INFO) |
1457 | printf("%s:full buffer\n" , |
1458 | "ipf_p_ftp_process" ); |
1459 | f->ftps_rptr = f->ftps_buf; |
1460 | f->ftps_wptr = f->ftps_buf; |
1461 | rptr = f->ftps_rptr; |
1462 | wptr = f->ftps_wptr; |
1463 | continue; |
1464 | } |
1465 | } |
1466 | } |
1467 | |
1468 | while ((f->ftps_junk == FTPXY_JUNK_OK) && (wptr > rptr)) { |
1469 | len = wptr - rptr; |
1470 | f->ftps_junk = ipf_p_ftp_valid(softf, ftp, rv, |
1471 | rptr, len); |
1472 | |
1473 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE) { |
1474 | printf("%s=%d len %d rv %d ptr %lx/%lx " , |
1475 | "ipf_p_ftp_valid" , |
1476 | f->ftps_junk, len, rv, (u_long)rptr, |
1477 | (u_long)wptr); |
1478 | printf("buf [%*.*s]\n" , len, len, rptr); |
1479 | } |
1480 | |
1481 | if (f->ftps_junk == FTPXY_JUNK_OK) { |
1482 | f->ftps_cmds++; |
1483 | f->ftps_rptr = rptr; |
1484 | if (rv) |
1485 | inc += ipf_p_ftp_server(softf, fin, ip, |
1486 | nat, ftp, len); |
1487 | else |
1488 | inc += ipf_p_ftp_client(softf, fin, ip, |
1489 | nat, ftp, len); |
1490 | rptr = f->ftps_rptr; |
1491 | wptr = f->ftps_wptr; |
1492 | } |
1493 | } |
1494 | |
1495 | /* |
1496 | * Off to a bad start so lets just forget about using the |
1497 | * ftp proxy for this connection. |
1498 | */ |
1499 | if ((f->ftps_cmds == 0) && (f->ftps_junk == FTPXY_JUNK_BAD)) { |
1500 | /* f->ftps_seq[1] += inc; */ |
1501 | |
1502 | DT(ftp_junk_cmd); |
1503 | if (softf->ipf_p_ftp_debug & DEBUG_ERROR) |
1504 | printf("%s:cmds == 0 junk == 1\n" , |
1505 | "ipf_p_ftp_process" ); |
1506 | return APR_ERR(2); |
1507 | } |
1508 | |
1509 | retry = 0; |
1510 | if ((f->ftps_junk != FTPXY_JUNK_OK) && (rptr < wptr)) { |
1511 | for (s = rptr; s < wptr; s++) { |
1512 | if ((*s == '\r') && (s + 1 < wptr) && |
1513 | (*(s + 1) == '\n')) { |
1514 | rptr = s + 2; |
1515 | retry = 1; |
1516 | if (f->ftps_junk != FTPXY_JUNK_CONT) |
1517 | f->ftps_junk = FTPXY_JUNK_OK; |
1518 | break; |
1519 | } |
1520 | } |
1521 | } |
1522 | |
1523 | if (rptr == wptr) { |
1524 | rptr = wptr = f->ftps_buf; |
1525 | } else { |
1526 | /* |
1527 | * Compact the buffer back to the start. The junk |
1528 | * flag should already be set and because we're not |
1529 | * throwing away any data, it is preserved from its |
1530 | * current state. |
1531 | */ |
1532 | if (rptr > f->ftps_buf) { |
1533 | bcopy(rptr, f->ftps_buf, wptr - rptr); |
1534 | wptr -= rptr - f->ftps_buf; |
1535 | rptr = f->ftps_buf; |
1536 | } |
1537 | } |
1538 | f->ftps_rptr = rptr; |
1539 | f->ftps_wptr = wptr; |
1540 | if (retry) |
1541 | goto whilemore; |
1542 | } |
1543 | |
1544 | /* f->ftps_seq[1] += inc; */ |
1545 | if (tcp->th_flags & TH_FIN) |
1546 | f->ftps_seq[1]++; |
1547 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_INFO) { |
1548 | #ifdef __sgi |
1549 | mlen = fin->fin_plen; |
1550 | #else |
1551 | mlen = MSGDSIZE(m); |
1552 | #endif |
1553 | mlen -= off; |
1554 | printf("ftps_seq[1] = %x inc %d len %d\n" , |
1555 | f->ftps_seq[1], inc, mlen); |
1556 | } |
1557 | |
1558 | f->ftps_rptr = rptr; |
1559 | f->ftps_wptr = wptr; |
1560 | return APR_INC(inc); |
1561 | } |
1562 | |
1563 | |
1564 | int |
1565 | ipf_p_ftp_out(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat) |
1566 | { |
1567 | ipf_ftp_softc_t *softf = arg; |
1568 | ftpinfo_t *ftp; |
1569 | int rev; |
1570 | |
1571 | ftp = aps->aps_data; |
1572 | if (ftp == NULL) |
1573 | return 0; |
1574 | |
1575 | rev = (nat->nat_dir == NAT_OUTBOUND) ? 0 : 1; |
1576 | if (ftp->ftp_side[1 - rev].ftps_ifp == NULL) |
1577 | ftp->ftp_side[1 - rev].ftps_ifp = fin->fin_ifp; |
1578 | |
1579 | return ipf_p_ftp_process(softf, fin, nat, ftp, rev); |
1580 | } |
1581 | |
1582 | |
1583 | int |
1584 | ipf_p_ftp_in(void *arg, fr_info_t *fin, ap_session_t *aps, nat_t *nat) |
1585 | { |
1586 | ipf_ftp_softc_t *softf = arg; |
1587 | ftpinfo_t *ftp; |
1588 | int rev; |
1589 | |
1590 | ftp = aps->aps_data; |
1591 | if (ftp == NULL) |
1592 | return 0; |
1593 | |
1594 | rev = (nat->nat_dir == NAT_OUTBOUND) ? 0 : 1; |
1595 | if (ftp->ftp_side[rev].ftps_ifp == NULL) |
1596 | ftp->ftp_side[rev].ftps_ifp = fin->fin_ifp; |
1597 | |
1598 | return ipf_p_ftp_process(softf, fin, nat, ftp, 1 - rev); |
1599 | } |
1600 | |
1601 | |
1602 | /* |
1603 | * ipf_p_ftp_atoi - implement a version of atoi which processes numbers in |
1604 | * pairs separated by commas (which are expected to be in the range 0 - 255), |
1605 | * returning a 16 bit number combining either side of the , as the MSB and |
1606 | * LSB. |
1607 | */ |
1608 | u_short |
1609 | ipf_p_ftp_atoi(char **ptr) |
1610 | { |
1611 | register char *s = *ptr, c; |
1612 | register u_char i = 0, j = 0; |
1613 | |
1614 | while (((c = *s++) != '\0') && ISDIGIT(c)) { |
1615 | i *= 10; |
1616 | i += c - '0'; |
1617 | } |
1618 | if (c != ',') { |
1619 | *ptr = NULL; |
1620 | return 0; |
1621 | } |
1622 | while (((c = *s++) != '\0') && ISDIGIT(c)) { |
1623 | j *= 10; |
1624 | j += c - '0'; |
1625 | } |
1626 | *ptr = s; |
1627 | i &= 0xff; |
1628 | j &= 0xff; |
1629 | return (i << 8) | j; |
1630 | } |
1631 | |
1632 | |
1633 | int |
1634 | ipf_p_ftp_eprt(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat, |
1635 | ftpinfo_t *ftp, int dlen) |
1636 | { |
1637 | ftpside_t *f; |
1638 | |
1639 | /* |
1640 | * Check for client sending out EPRT message. |
1641 | */ |
1642 | if (dlen < IPF_MINEPRTLEN) { |
1643 | DT1(epert_dlen, int, dlen); |
1644 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR) |
1645 | printf("ipf_p_ftp_eprt:dlen(%d) < IPF_MINEPRTLEN\n" , |
1646 | dlen); |
1647 | return 0; |
1648 | } |
1649 | |
1650 | /* |
1651 | * Parse the EPRT command. Format is: |
1652 | * "EPRT |1|1.2.3.4|2000|" for IPv4 and |
1653 | * "EPRT |2|ef00::1:2|2000|" for IPv6 |
1654 | */ |
1655 | f = &ftp->ftp_side[0]; |
1656 | if (f->ftps_rptr[5] != '|') |
1657 | return 0; |
1658 | if (f->ftps_rptr[5] == f->ftps_rptr[7]) { |
1659 | if (f->ftps_rptr[6] == '1' && nat->nat_v[0] == 4) |
1660 | return ipf_p_ftp_eprt4(softf, fin, ip, nat, ftp, dlen); |
1661 | #ifdef USE_INET6 |
1662 | if (f->ftps_rptr[6] == '2' && nat->nat_v[0] == 6) |
1663 | return ipf_p_ftp_eprt6(softf, fin, ip, nat, ftp, dlen); |
1664 | #endif |
1665 | } |
1666 | return 0; |
1667 | } |
1668 | |
1669 | |
1670 | int |
1671 | ipf_p_ftp_eprt4(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat, |
1672 | ftpinfo_t *ftp, int dlen) |
1673 | { |
1674 | int a1, a2, a3, a4, port, olen, nlen, inc, off; |
1675 | char newbuf[IPF_FTPBUFSZ]; |
1676 | char *s, c, delim; |
1677 | u_32_t addr, i; |
1678 | tcphdr_t *tcp; |
1679 | ftpside_t *f; |
1680 | mb_t *m; |
1681 | |
1682 | m = fin->fin_m; |
1683 | tcp = (tcphdr_t *)fin->fin_dp; |
1684 | off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff; |
1685 | f = &ftp->ftp_side[0]; |
1686 | delim = f->ftps_rptr[5]; |
1687 | s = f->ftps_rptr + 8; |
1688 | |
1689 | /* |
1690 | * get the IP address. |
1691 | */ |
1692 | i = 0; |
1693 | while (((c = *s++) != '\0') && ISDIGIT(c)) { |
1694 | i *= 10; |
1695 | i += c - '0'; |
1696 | } |
1697 | if (i > 255) |
1698 | return 0; |
1699 | if (c != '.') |
1700 | return 0; |
1701 | addr = (i << 24); |
1702 | |
1703 | i = 0; |
1704 | while (((c = *s++) != '\0') && ISDIGIT(c)) { |
1705 | i *= 10; |
1706 | i += c - '0'; |
1707 | } |
1708 | if (i > 255) |
1709 | return 0; |
1710 | if (c != '.') |
1711 | return 0; |
1712 | addr |= (addr << 16); |
1713 | |
1714 | i = 0; |
1715 | while (((c = *s++) != '\0') && ISDIGIT(c)) { |
1716 | i *= 10; |
1717 | i += c - '0'; |
1718 | } |
1719 | if (i > 255) |
1720 | return 0; |
1721 | if (c != '.') |
1722 | return 0; |
1723 | addr |= (addr << 8); |
1724 | |
1725 | i = 0; |
1726 | while (((c = *s++) != '\0') && ISDIGIT(c)) { |
1727 | i *= 10; |
1728 | i += c - '0'; |
1729 | } |
1730 | if (i > 255) |
1731 | return 0; |
1732 | if (c != delim) |
1733 | return 0; |
1734 | addr |= addr; |
1735 | |
1736 | /* |
1737 | * Get the port number |
1738 | */ |
1739 | i = 0; |
1740 | while (((c = *s++) != '\0') && ISDIGIT(c)) { |
1741 | i *= 10; |
1742 | i += c - '0'; |
1743 | } |
1744 | if (i > 65535) |
1745 | return 0; |
1746 | if (c != delim) |
1747 | return 0; |
1748 | port = i; |
1749 | |
1750 | /* |
1751 | * Check for CR-LF at the end of the command string. |
1752 | */ |
1753 | if ((*s != '\r') || (*(s + 1) != '\n')) { |
1754 | DT(eprt4_no_crlf); |
1755 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR) |
1756 | printf("ipf_p_ftp_eprt4:missing %s\n" , "cr-lf" ); |
1757 | return 0; |
1758 | } |
1759 | s += 2; |
1760 | |
1761 | /* |
1762 | * Calculate new address parts for PORT command |
1763 | */ |
1764 | if (nat->nat_dir == NAT_INBOUND) |
1765 | a1 = ntohl(nat->nat_odstaddr); |
1766 | else |
1767 | a1 = ntohl(ip->ip_src.s_addr); |
1768 | a2 = (a1 >> 16) & 0xff; |
1769 | a3 = (a1 >> 8) & 0xff; |
1770 | a4 = a1 & 0xff; |
1771 | a1 >>= 24; |
1772 | olen = s - f->ftps_rptr; |
1773 | /* |
1774 | * While we could force the use of | as a delimiter here, it makes |
1775 | * sense to preserve whatever character is being used by the systems |
1776 | * involved in the communication. |
1777 | */ |
1778 | snprintf(newbuf, sizeof(newbuf), "%s %c1%c%u.%u.%u.%u%c%u%c\r\n" , |
1779 | "EPRT" , delim, delim, a1, a2, a3, a4, delim, port, delim); |
1780 | |
1781 | nlen = strlen(newbuf); |
1782 | inc = nlen - olen; |
1783 | if ((inc + fin->fin_plen) > 65535) { |
1784 | DT2(eprt4_len, int, inc, int, fin->fin_plen); |
1785 | if (softf->ipf_p_ftp_debug & DEBUG_ERROR) |
1786 | printf("ipf_p_ftp_eprt4:inc(%d) + ip->ip_len > 65535\n" , |
1787 | inc); |
1788 | return 0; |
1789 | } |
1790 | |
1791 | off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff; |
1792 | #if !defined(_KERNEL) |
1793 | M_ADJ(m, inc); |
1794 | #else |
1795 | if (inc < 0) |
1796 | M_ADJ(m, inc); |
1797 | #endif |
1798 | /* the mbuf chain will be extended if necessary by m_copyback() */ |
1799 | COPYBACK(m, off, nlen, newbuf); |
1800 | fin->fin_flx |= FI_DOCKSUM; |
1801 | |
1802 | if (inc != 0) { |
1803 | fin->fin_plen += inc; |
1804 | ip->ip_len = htons(fin->fin_plen); |
1805 | fin->fin_dlen += inc; |
1806 | } |
1807 | |
1808 | f->ftps_cmd = FTPXY_C_EPRT; |
1809 | return ipf_p_ftp_addport(softf, fin, ip, nat, ftp, dlen, port, inc); |
1810 | } |
1811 | |
1812 | |
1813 | int |
1814 | ipf_p_ftp_epsv(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, nat_t *nat, |
1815 | ftpinfo_t *ftp, int dlen) |
1816 | { |
1817 | char newbuf[IPF_FTPBUFSZ]; |
1818 | u_short ap = 0; |
1819 | ftpside_t *f; |
1820 | char *s; |
1821 | |
1822 | if ((softf->ipf_p_ftp_forcepasv != 0) && |
1823 | (ftp->ftp_side[0].ftps_cmd != FTPXY_C_EPSV)) { |
1824 | DT1(epsv_cmd, int, ftp->ftp_side[0].ftps_cmd); |
1825 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR) |
1826 | printf("ipf_p_ftp_epsv:ftps_cmd(%d) != FTPXY_C_EPSV\n" , |
1827 | ftp->ftp_side[0].ftps_cmd); |
1828 | return 0; |
1829 | } |
1830 | f = &ftp->ftp_side[1]; |
1831 | |
1832 | #define EPSV_REPLEN 33 |
1833 | /* |
1834 | * Check for EPSV reply message. |
1835 | */ |
1836 | if (dlen < IPF_MIN229LEN) { |
1837 | return (0); |
1838 | } else if (strncmp(f->ftps_rptr, |
1839 | "229 Entering Extended Passive Mode" , EPSV_REPLEN)) { |
1840 | return (0); |
1841 | } |
1842 | |
1843 | /* |
1844 | * Skip the EPSV command + space |
1845 | */ |
1846 | s = f->ftps_rptr + 33; |
1847 | while (*s && !ISDIGIT(*s)) |
1848 | s++; |
1849 | |
1850 | /* |
1851 | * As per RFC 2428, there are no addres components in the EPSV |
1852 | * response. So we'll go straight to getting the port. |
1853 | */ |
1854 | while (*s && ISDIGIT(*s)) { |
1855 | ap *= 10; |
1856 | ap += *s++ - '0'; |
1857 | } |
1858 | |
1859 | if (!s) { |
1860 | return 0; |
1861 | } |
1862 | |
1863 | if (*s == '|') |
1864 | s++; |
1865 | if (*s == ')') |
1866 | s++; |
1867 | if (*s == '\n') |
1868 | s--; |
1869 | /* |
1870 | * check for CR-LF at the end. |
1871 | */ |
1872 | if ((*s != '\r') || (*(s + 1) != '\n')) { |
1873 | return 0; |
1874 | } |
1875 | s += 2; |
1876 | |
1877 | snprintf(newbuf, sizeof(newbuf), "%s (|||%u|)\r\n" , |
1878 | "229 Entering Extended Passive Mode" , ap); |
1879 | |
1880 | return ipf_p_ftp_pasvreply(softf, fin, ip, nat, ftp, (u_int)ap, |
1881 | newbuf, s); |
1882 | } |
1883 | |
1884 | #ifdef USE_INET6 |
1885 | int |
1886 | ipf_p_ftp_eprt6(ipf_ftp_softc_t *softf, fr_info_t *fin, ip_t *ip, |
1887 | nat_t *nat, ftpinfo_t *ftp, int dlen) |
1888 | { |
1889 | int port, olen, nlen, inc, off, left, i; |
1890 | char newbuf[IPF_FTPBUFSZ]; |
1891 | char *s, c; |
1892 | i6addr_t addr, *a6; |
1893 | tcphdr_t *tcp; |
1894 | ip6_t *ip6; |
1895 | char delim; |
1896 | u_short whole; |
1897 | u_short part; |
1898 | ftpside_t *f; |
1899 | u_short *t; |
1900 | int fwd; |
1901 | mb_t *m; |
1902 | u_32_t a; |
1903 | |
1904 | m = fin->fin_m; |
1905 | ip6 = (ip6_t *)ip; |
1906 | f = &ftp->ftp_side[0]; |
1907 | s = f->ftps_rptr + 8; |
1908 | f = &ftp->ftp_side[0]; |
1909 | delim = f->ftps_rptr[5]; |
1910 | tcp = (tcphdr_t *)fin->fin_dp; |
1911 | off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff; |
1912 | |
1913 | addr.i6[0] = 0; |
1914 | addr.i6[1] = 0; |
1915 | addr.i6[2] = 0; |
1916 | addr.i6[3] = 0; |
1917 | /* |
1918 | * Parse an IPv6 address. |
1919 | * Go forward until either :: or | is found. If :: is found, |
1920 | * reverse direction. Direction change is performed to ease |
1921 | * parsing an unknown number of 0s in the middle. |
1922 | */ |
1923 | whole = 0; |
1924 | t = (u_short *)&addr; |
1925 | fwd = 1; |
1926 | for (part = 0; (c = *s) != '\0'; ) { |
1927 | if (c == delim) { |
1928 | *t = htons((u_short)whole); |
1929 | break; |
1930 | } |
1931 | if (c == ':') { |
1932 | *t = part; |
1933 | if (fwd) { |
1934 | *t = htons((u_short)whole); |
1935 | t++; |
1936 | } else { |
1937 | *t = htons((u_short)(whole >> 16)); |
1938 | t--; |
1939 | } |
1940 | whole = 0; |
1941 | if (fwd == 1 && s[1] == ':') { |
1942 | while (*s && *s != '|') |
1943 | s++; |
1944 | if ((c = *s) != delim) |
1945 | break; |
1946 | t = (u_short *)&addr.i6[3]; |
1947 | t++; |
1948 | fwd = 0; |
1949 | } else if (fwd == 0 && s[-1] == ':') { |
1950 | break; |
1951 | } |
1952 | } else { |
1953 | if (c >= '0' && c <= '9') { |
1954 | c -= '0'; |
1955 | } else if (c >= 'a' && c <= 'f') { |
1956 | c -= 'a' + 10; |
1957 | } else if (c >= 'A' && c <= 'F') { |
1958 | c -= 'A' + 10; |
1959 | } |
1960 | if (fwd) { |
1961 | whole <<= 8; |
1962 | whole |= c; |
1963 | } else { |
1964 | whole >>= 8; |
1965 | whole |= ((u_32_t)c) << 24; |
1966 | } |
1967 | } |
1968 | if (fwd) |
1969 | s++; |
1970 | else |
1971 | s--; |
1972 | } |
1973 | if (c != ':' && c != delim) |
1974 | return 0; |
1975 | |
1976 | while (*s != '|') |
1977 | s++; |
1978 | s++; |
1979 | |
1980 | /* |
1981 | * Get the port number |
1982 | */ |
1983 | i = 0; |
1984 | while (((c = *s++) != '\0') && ISDIGIT(c)) { |
1985 | i *= 10; |
1986 | i += c - '0'; |
1987 | } |
1988 | if (i > 65535) |
1989 | return 0; |
1990 | if (c != delim) |
1991 | return 0; |
1992 | port = (u_short)(i & 0xffff); |
1993 | |
1994 | /* |
1995 | * Check for CR-LF at the end of the command string. |
1996 | */ |
1997 | if ((*s != '\r') || (*(s + 1) != '\n')) { |
1998 | DT(eprt6_no_crlf); |
1999 | if (softf->ipf_p_ftp_debug & DEBUG_PARSE_ERR) |
2000 | printf("ipf_p_ftp_eprt6:missing %s\n" , "cr-lf" ); |
2001 | return 0; |
2002 | } |
2003 | s += 2; |
2004 | |
2005 | /* |
2006 | * Calculate new address parts for PORT command |
2007 | */ |
2008 | a6 = (i6addr_t *)&ip6->ip6_src; |
2009 | olen = s - f->ftps_rptr; |
2010 | /* DO NOT change this to snprintf! */ |
2011 | /* |
2012 | * While we could force the use of | as a delimiter here, it makes |
2013 | * sense to preserve whatever character is being used by the systems |
2014 | * involved in the communication. |
2015 | */ |
2016 | s = newbuf; |
2017 | left = sizeof(newbuf); |
2018 | snprintf(newbuf, left, "EPRT %c2%c" , delim, delim); |
2019 | left -= strlen(s) + 1; |
2020 | s += strlen(s); |
2021 | a = ntohl(a6->i6[0]); |
2022 | snprintf(s, left, "%x:%x:" , a >> 16, a & 0xffff); |
2023 | left -= strlen(s); |
2024 | s += strlen(s); |
2025 | a = ntohl(a6->i6[1]); |
2026 | snprintf(s, left, "%x:%x:" , a >> 16, a & 0xffff); |
2027 | left -= strlen(s); |
2028 | s += strlen(s); |
2029 | a = ntohl(a6->i6[2]); |
2030 | snprintf(s, left, "%x:%x:" , a >> 16, a & 0xffff); |
2031 | left -= strlen(s); |
2032 | s += strlen(s); |
2033 | a = ntohl(a6->i6[3]); |
2034 | snprintf(s, left, "%x:%x" , a >> 16, a & 0xffff); |
2035 | left -= strlen(s); |
2036 | s += strlen(s); |
2037 | snprintf(s, left, "|%d|\r\n" , port); |
2038 | nlen = strlen(newbuf); |
2039 | inc = nlen - olen; |
2040 | if ((inc + fin->fin_plen) > 65535) { |
2041 | DT2(eprt6_len, int, inc, int, fin->fin_plen); |
2042 | if (softf->ipf_p_ftp_debug & DEBUG_ERROR) |
2043 | printf("ipf_p_ftp_eprt6:inc(%d) + ip->ip_len > 65535\n" , |
2044 | inc); |
2045 | return 0; |
2046 | } |
2047 | |
2048 | off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff; |
2049 | #if !defined(_KERNEL) |
2050 | M_ADJ(m, inc); |
2051 | #else |
2052 | if (inc < 0) |
2053 | M_ADJ(m, inc); |
2054 | #endif |
2055 | /* the mbuf chain will be extended if necessary by m_copyback() */ |
2056 | COPYBACK(m, off, nlen, newbuf); |
2057 | fin->fin_flx |= FI_DOCKSUM; |
2058 | |
2059 | if (inc != 0) { |
2060 | fin->fin_plen += inc; |
2061 | ip6->ip6_plen = htons(fin->fin_plen - fin->fin_hlen); |
2062 | fin->fin_dlen += inc; |
2063 | } |
2064 | |
2065 | f->ftps_cmd = FTPXY_C_EPRT; |
2066 | return ipf_p_ftp_addport(softf, fin, ip, nat, ftp, dlen, port, inc); |
2067 | } |
2068 | #endif /* USE_INET6 */ |
2069 | |