xref: /illumos-gate/usr/src/uts/common/inet/ipf/netinet/ip_ftp_pxy.c (revision 55fea89dcaa64928bed4327112404dcb3e07b79f)
1 /*
2  * Copyright (C) 1997-2003 by Darren Reed
3  *
4  * See the IPFILTER.LICENCE file for details on licencing.
5  *
6  * $Id: ip_ftp_pxy.c,v 2.88.2.15 2005/03/19 19:38:10 darrenr Exp $
7  *
8  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
9  * Use is subject to license terms.
10  *
11  * Simple FTP transparent proxy for in-kernel use.  For use with the NAT
12  * code.
13 */
14 
15 #define	IPF_FTP_PROXY
16 
17 #define	IPF_MINPORTLEN	18
18 #define	IPF_MAXPORTLEN	30
19 #define	IPF_MIN227LEN	39
20 #define	IPF_MAX227LEN	51
21 #define	IPF_MIN229LEN	47
22 #define	IPF_MAX229LEN	51
23 
24 #define	FTPXY_GO	0
25 #define	FTPXY_INIT	1
26 #define	FTPXY_USER_1	2
27 #define	FTPXY_USOK_1	3
28 #define	FTPXY_PASS_1	4
29 #define	FTPXY_PAOK_1	5
30 #define	FTPXY_AUTH_1	6
31 #define	FTPXY_AUOK_1	7
32 #define	FTPXY_ADAT_1	8
33 #define	FTPXY_ADOK_1	9
34 #define	FTPXY_ACCT_1	10
35 #define	FTPXY_ACOK_1	11
36 #define	FTPXY_USER_2	12
37 #define	FTPXY_USOK_2	13
38 #define	FTPXY_PASS_2	14
39 #define	FTPXY_PAOK_2	15
40 
41 /*
42  * Values for FTP commands.  Numerics cover 0-999
43  */
44 #define	FTPXY_C_PASV	1000
45 
46 typedef struct ifs_ftppxy {
47 	frentry_t		ftppxyfr;
48 	int			ftp_proxy_init;
49 	int			ippr_ftp_pasvonly;
50 	int			ippr_ftp_insecure;
51 				/* Do not require logins before transfers */
52 	int			ippr_ftp_pasvrdr;
53 	int			ippr_ftp_forcepasv;
54 				/* PASV must be last command prior to 227 */
55 	/*
56 	 * 1 - security
57 	 * 2 - errors
58 	 * 3 - error debugging
59 	 * 4 - parsing errors
60 	 * 5 - parsing info
61 	 * 6 - parsing debug
62 	 */
63 	int			ippr_ftp_debug;
64 	ipftuneable_t		ftptune;
65 } ifs_ftppxy_t;
66 
67 int ippr_ftp_client __P((fr_info_t *, ip_t *, nat_t *, ftpinfo_t *, int,
68     ifs_ftppxy_t *));
69 int ippr_ftp_complete __P((char *, size_t));
70 int ippr_ftp_in __P((fr_info_t *, ap_session_t *, nat_t *, void *));
71 int ippr_ftp_init __P((void **, ipf_stack_t *));
72 void ippr_ftp_fini __P((void **, ipf_stack_t *));
73 int ippr_ftp_new __P((fr_info_t *, ap_session_t *, nat_t *, void *));
74 int ippr_ftp_out __P((fr_info_t *, ap_session_t *, nat_t *, void *));
75 int ippr_ftp_pasv __P((fr_info_t *, ip_t *, nat_t *, ftpinfo_t *, int,
76     ifs_ftppxy_t *));
77 int ippr_ftp_epsv __P((fr_info_t *, ip_t *, nat_t *, ftpside_t *, int,
78     ifs_ftppxy_t *));
79 int ippr_ftp_port __P((fr_info_t *, ip_t *, nat_t *, ftpside_t *, int,
80     ifs_ftppxy_t *));
81 int ippr_ftp_process __P((fr_info_t *, nat_t *, ftpinfo_t *, int,
82     ifs_ftppxy_t *));
83 int ippr_ftp_server __P((fr_info_t *, ip_t *, nat_t *, ftpinfo_t *, int,
84     ifs_ftppxy_t *));
85 int ippr_ftp_valid __P((ftpinfo_t *, int, char *, size_t, ifs_ftppxy_t *));
86 int ippr_ftp_server_valid __P((ftpside_t *, char *, size_t, ifs_ftppxy_t *));
87 int ippr_ftp_client_valid __P((ftpside_t *, char *, size_t, ifs_ftppxy_t *));
88 u_short ippr_ftp_atoi __P((char **));
89 int ippr_ftp_pasvreply __P((fr_info_t *, ip_t *, nat_t *, ftpside_t *,
90 			    u_int, char *, char *, u_int, ifs_ftppxy_t *));
91 
92 /*
93  * Initialize local structures.
94  */
ippr_ftp_init(private,ifs)95 int ippr_ftp_init(private, ifs)
96 void **private;
97 ipf_stack_t *ifs;
98 {
99 	ifs_ftppxy_t *ifsftp;
100 
101 	KMALLOC(ifsftp, ifs_ftppxy_t *);
102 	if (ifsftp == NULL)
103 		return -1;
104 
105 	bzero((char *)&ifsftp->ftppxyfr, sizeof(ifsftp->ftppxyfr));
106 	ifsftp->ftppxyfr.fr_ref = 1;
107 	ifsftp->ftppxyfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
108 	MUTEX_INIT(&ifsftp->ftppxyfr.fr_lock, "FTP Proxy Mutex");
109 	ifsftp->ftp_proxy_init = 1;
110 	ifsftp->ippr_ftp_pasvonly = 0;
111 	ifsftp->ippr_ftp_insecure = 0;
112 	ifsftp->ippr_ftp_pasvrdr = 0;
113 	ifsftp->ippr_ftp_forcepasv = 0;
114 #if defined(_KERNEL)
115 	ifsftp->ippr_ftp_debug = 0;
116 #else
117 	ifsftp->ippr_ftp_debug = 2;
118 #endif
119 	bzero((char *)&ifsftp->ftptune, sizeof(ifsftp->ftptune));
120 	ifsftp->ftptune.ipft_pint = (uint_t *)&ifsftp->ippr_ftp_debug;
121 	ifsftp->ftptune.ipft_name = "ippr_ftp_debug";
122 	ifsftp->ftptune.ipft_max = 10;
123 	ifsftp->ftptune.ipft_sz = sizeof(ifsftp->ippr_ftp_debug);
124 	ifsftp->ftptune.ipft_next = NULL;
125 
126 	(void) fr_addipftune(&ifsftp->ftptune, ifs);
127 
128 	*private = (void *)ifsftp;
129 
130 	return 0;
131 }
132 
133 
ippr_ftp_fini(private,ifs)134 void ippr_ftp_fini(private, ifs)
135 void **private;
136 ipf_stack_t *ifs;
137 {
138 	ifs_ftppxy_t *ifsftp = *((ifs_ftppxy_t **)private);
139 
140 	(void) fr_delipftune(&ifsftp->ftptune, ifs);
141 
142 	if (ifsftp->ftp_proxy_init == 1) {
143 		MUTEX_DESTROY(&ifsftp->ftppxyfr.fr_lock);
144 		ifsftp->ftp_proxy_init = 0;
145 	}
146 
147 	KFREE(ifsftp);
148 	*private = NULL;
149 }
150 
151 
152 /*ARGSUSED*/
ippr_ftp_new(fin,aps,nat,private)153 int ippr_ftp_new(fin, aps, nat, private)
154 fr_info_t *fin;
155 ap_session_t *aps;
156 nat_t *nat;
157 void *private;
158 {
159 	ftpinfo_t *ftp;
160 	ftpside_t *f;
161 
162 	KMALLOC(ftp, ftpinfo_t *);
163 	if (ftp == NULL)
164 		return -1;
165 
166 	fin = fin;	/* LINT */
167 	nat = nat;	/* LINT */
168 
169 	aps->aps_data = ftp;
170 	aps->aps_psiz = sizeof(ftpinfo_t);
171 
172 	bzero((char *)ftp, sizeof(*ftp));
173 	f = &ftp->ftp_side[0];
174 	f->ftps_rptr = f->ftps_buf;
175 	f->ftps_wptr = f->ftps_buf;
176 	f = &ftp->ftp_side[1];
177 	f->ftps_rptr = f->ftps_buf;
178 	f->ftps_wptr = f->ftps_buf;
179 	ftp->ftp_passok = FTPXY_INIT;
180 	ftp->ftp_incok = 0;
181 	return 0;
182 }
183 
184 
ippr_ftp_port(fin,ip,nat,f,dlen,ifsftp)185 int ippr_ftp_port(fin, ip, nat, f, dlen, ifsftp)
186 fr_info_t *fin;
187 ip_t *ip;
188 nat_t *nat;
189 ftpside_t *f;
190 int dlen;
191 ifs_ftppxy_t *ifsftp;
192 {
193 	tcphdr_t *tcp, tcph, *tcp2 = &tcph;
194 	char newbuf[IPF_FTPBUFSZ], *s;
195 	struct in_addr swip, swip2;
196 	u_int a1, a2, a3, a4;
197 	int inc, off, flags;
198 	u_short a5, a6, sp;
199 	size_t nlen, olen;
200 	fr_info_t fi;
201 	nat_t *nat2;
202 	mb_t *m;
203 	ipf_stack_t *ifs = fin->fin_ifs;
204 
205 	m = fin->fin_m;
206 	tcp = (tcphdr_t *)fin->fin_dp;
207 	off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
208 
209 	/*
210 	 * Check for client sending out PORT message.
211 	 */
212 	if (dlen < IPF_MINPORTLEN) {
213 		if (ifsftp->ippr_ftp_debug > 1)
214 			printf("ippr_ftp_port:dlen(%d) < IPF_MINPORTLEN\n",
215 			       dlen);
216 		return 0;
217 	}
218 	/*
219 	 * Skip the PORT command + space
220 	 */
221 	s = f->ftps_rptr + 5;
222 	/*
223 	 * Pick out the address components, two at a time.
224 	 */
225 	a1 = ippr_ftp_atoi(&s);
226 	if (s == NULL) {
227 		if (ifsftp->ippr_ftp_debug > 1)
228 			printf("ippr_ftp_port:ippr_ftp_atoi(%d) failed\n", 1);
229 		return 0;
230 	}
231 	a2 = ippr_ftp_atoi(&s);
232 	if (s == NULL) {
233 		if (ifsftp->ippr_ftp_debug > 1)
234 			printf("ippr_ftp_port:ippr_ftp_atoi(%d) failed\n", 2);
235 		return 0;
236 	}
237 
238 	/*
239 	 * Check that IP address in the PORT/PASV reply is the same as the
240 	 * sender of the command - prevents using PORT for port scanning.
241 	 */
242 	a1 <<= 16;
243 	a1 |= a2;
244 	if (((nat->nat_dir == NAT_OUTBOUND) &&
245 	     (a1 != ntohl(nat->nat_inip.s_addr))) ||
246 	    ((nat->nat_dir == NAT_INBOUND) &&
247 	     (a1 != ntohl(nat->nat_oip.s_addr)))) {
248 		if (ifsftp->ippr_ftp_debug > 0)
249 			printf("ippr_ftp_port:%s != nat->nat_inip\n", "a1");
250 		return APR_ERR(1);
251 	}
252 
253 	a5 = ippr_ftp_atoi(&s);
254 	if (s == NULL) {
255 		if (ifsftp->ippr_ftp_debug > 1)
256 			printf("ippr_ftp_port:ippr_ftp_atoi(%d) failed\n", 3);
257 		return 0;
258 	}
259 	if (*s == ')')
260 		s++;
261 
262 	/*
263 	 * check for CR-LF at the end.
264 	 */
265 	if (*s == '\n')
266 		s--;
267 	if ((*s == '\r') && (*(s + 1) == '\n')) {
268 		s += 2;
269 		a6 = a5 & 0xff;
270 	} else {
271 		if (ifsftp->ippr_ftp_debug > 1)
272 			printf("ippr_ftp_port:missing %s\n", "cr-lf");
273 		return 0;
274 	}
275 
276 	a5 >>= 8;
277 	a5 &= 0xff;
278 	sp = a5 << 8 | a6;
279 	/*
280 	 * Don't allow the PORT command to specify a port < 1024 due to
281 	 * security crap.
282 	 */
283 	if (sp < 1024) {
284 		if (ifsftp->ippr_ftp_debug > 0)
285 			printf("ippr_ftp_port:sp(%d) < 1024\n", sp);
286 		return 0;
287 	}
288 	/*
289 	 * Calculate new address parts for PORT command
290 	 */
291 	if (nat->nat_dir == NAT_INBOUND)
292 		a1 = ntohl(nat->nat_oip.s_addr);
293 	else
294 		a1 = ntohl(ip->ip_src.s_addr);
295 	a2 = (a1 >> 16) & 0xff;
296 	a3 = (a1 >> 8) & 0xff;
297 	a4 = a1 & 0xff;
298 	a1 >>= 24;
299 	olen = s - f->ftps_rptr;
300 	/* DO NOT change this to snprintf! */
301 #if defined(SNPRINTF) && defined(_KERNEL)
302 	(void) SNPRINTF(newbuf, sizeof(newbuf), "%s %u,%u,%u,%u,%u,%u\r\n",
303 		 "PORT", a1, a2, a3, a4, a5, a6);
304 #else
305 	(void) sprintf(newbuf, "%s %u,%u,%u,%u,%u,%u\r\n",
306 		       "PORT", a1, a2, a3, a4, a5, a6);
307 #endif
308 
309 	nlen = strlen(newbuf);
310 	inc = nlen - olen;
311 	if ((inc + ip->ip_len) > 65535) {
312 		if (ifsftp->ippr_ftp_debug > 0)
313 			printf("ippr_ftp_port:inc(%d) + ip->ip_len > 65535\n",
314 			       inc);
315 		return 0;
316 	}
317 
318 #if !defined(_KERNEL)
319 	bcopy(newbuf, MTOD(m, char *) + off, nlen);
320 #else
321 # if defined(MENTAT)
322 	if (inc < 0)
323 		(void)adjmsg(m, inc);
324 # else /* defined(MENTAT) */
325 	/*
326 	 * m_adj takes care of pkthdr.len, if required and treats inc<0 to
327 	 * mean remove -len bytes from the end of the packet.
328 	 * The mbuf chain will be extended if necessary by m_copyback().
329 	 */
330 	if (inc < 0)
331 		m_adj(m, inc);
332 # endif /* defined(MENTAT) */
333 #endif /* !defined(_KERNEL) */
334 	COPYBACK(m, off, nlen, newbuf);
335 
336 	if (inc != 0) {
337 		ip->ip_len += inc;
338 		fin->fin_dlen += inc;
339 		fin->fin_plen += inc;
340 	}
341 
342 	/*
343 	 * The server may not make the connection back from port 20, but
344 	 * it is the most likely so use it here to check for a conflicting
345 	 * mapping.
346 	 */
347 	bcopy((char *)fin, (char *)&fi, sizeof(fi));
348 	fi.fin_flx |= FI_IGNORE;
349 	fi.fin_data[0] = sp;
350 	fi.fin_data[1] = fin->fin_data[1] - 1;
351 	/*
352 	 * Add skeleton NAT entry for connection which will come back the
353 	 * other way.
354 	 */
355 	if (nat->nat_dir == NAT_OUTBOUND)
356 		nat2 = nat_outlookup(&fi, NAT_SEARCH|IPN_TCP, nat->nat_p,
357 				     nat->nat_inip, nat->nat_oip);
358 	else
359 		nat2 = nat_inlookup(&fi, NAT_SEARCH|IPN_TCP, nat->nat_p,
360 				    nat->nat_inip, nat->nat_oip);
361 	if (nat2 == NULL) {
362 		int slen;
363 
364 		slen = ip->ip_len;
365 		ip->ip_len = fin->fin_hlen + sizeof(*tcp2);
366 		bzero((char *)tcp2, sizeof(*tcp2));
367 		tcp2->th_win = htons(8192);
368 		tcp2->th_sport = htons(sp);
369 		TCP_OFF_A(tcp2, 5);
370 		tcp2->th_flags = TH_SYN;
371 		tcp2->th_dport = 0; /* XXX - don't specify remote port */
372 		fi.fin_data[1] = 0;
373 		fi.fin_dlen = sizeof(*tcp2);
374 		fi.fin_plen = fi.fin_hlen + sizeof(*tcp2);
375 		fi.fin_dp = (char *)tcp2;
376 		fi.fin_fr = &ifsftp->ftppxyfr;
377 		fi.fin_out = nat->nat_dir;
378 		fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE;
379 		swip = ip->ip_src;
380 		swip2 = ip->ip_dst;
381 		if (nat->nat_dir == NAT_OUTBOUND) {
382 			fi.fin_fi.fi_saddr = nat->nat_inip.s_addr;
383 			ip->ip_src = nat->nat_inip;
384 		} else if (nat->nat_dir == NAT_INBOUND) {
385 			fi.fin_fi.fi_saddr = nat->nat_oip.s_addr;
386 			ip->ip_src = nat->nat_oip;
387 		}
388 
389 		flags = NAT_SLAVE|IPN_TCP|SI_W_DPORT;
390 		if (nat->nat_dir == NAT_INBOUND)
391 			flags |= NAT_NOTRULEPORT;
392 		nat2 = nat_new(&fi, nat->nat_ptr, NULL, flags, nat->nat_dir);
393 
394 		if (nat2 != NULL) {
395 			(void) nat_proto(&fi, nat2, IPN_TCP);
396 			nat_update(&fi, nat2, nat->nat_ptr);
397 			fi.fin_ifp = NULL;
398 			if (nat->nat_dir == NAT_INBOUND) {
399 				fi.fin_fi.fi_daddr = nat->nat_inip.s_addr;
400 				ip->ip_dst = nat->nat_inip;
401 			}
402 			(void) fr_addstate(&fi, &nat2->nat_state, SI_W_DPORT);
403 		}
404 		ip->ip_len = slen;
405 		ip->ip_src = swip;
406 		ip->ip_dst = swip2;
407 	} else {
408 		ipstate_t *is;
409 
410 		nat_update(&fi, nat2, nat->nat_ptr);
411 		READ_ENTER(&ifs->ifs_ipf_state);
412 		is = nat2->nat_state;
413 		if (is != NULL) {
414 			MUTEX_ENTER(&is->is_lock);
415 			(void)fr_tcp_age(&is->is_sti, &fi, ifs->ifs_ips_tqtqb,
416 				         is->is_flags);
417 			MUTEX_EXIT(&is->is_lock);
418 		}
419 		RWLOCK_EXIT(&ifs->ifs_ipf_state);
420 	}
421 	return APR_INC(inc);
422 }
423 
424 
ippr_ftp_client(fin,ip,nat,ftp,dlen,ifsftp)425 int ippr_ftp_client(fin, ip, nat, ftp, dlen, ifsftp)
426 fr_info_t *fin;
427 nat_t *nat;
428 ftpinfo_t *ftp;
429 ip_t *ip;
430 int dlen;
431 ifs_ftppxy_t *ifsftp;
432 {
433 	char *rptr, *wptr, cmd[6], c;
434 	ftpside_t *f;
435 	int inc, i;
436 
437 	inc = 0;
438 	f = &ftp->ftp_side[0];
439 	rptr = f->ftps_rptr;
440 	wptr = f->ftps_wptr;
441 
442 	for (i = 0; (i < 5) && (i < dlen); i++) {
443 		c = rptr[i];
444 		if (ISALPHA(c)) {
445 			cmd[i] = TOUPPER(c);
446 		} else {
447 			cmd[i] = c;
448 		}
449 	}
450 	cmd[i] = '\0';
451 
452 	ftp->ftp_incok = 0;
453 	if (!strncmp(cmd, "USER ", 5) || !strncmp(cmd, "XAUT ", 5)) {
454 		if (ftp->ftp_passok == FTPXY_ADOK_1 ||
455 		    ftp->ftp_passok == FTPXY_AUOK_1) {
456 			ftp->ftp_passok = FTPXY_USER_2;
457 			ftp->ftp_incok = 1;
458 		} else {
459 			ftp->ftp_passok = FTPXY_USER_1;
460 			ftp->ftp_incok = 1;
461 		}
462 	} else if (!strncmp(cmd, "AUTH ", 5)) {
463 		ftp->ftp_passok = FTPXY_AUTH_1;
464 		ftp->ftp_incok = 1;
465 	} else if (!strncmp(cmd, "PASS ", 5)) {
466 		if (ftp->ftp_passok == FTPXY_USOK_1) {
467 			ftp->ftp_passok = FTPXY_PASS_1;
468 			ftp->ftp_incok = 1;
469 		} else if (ftp->ftp_passok == FTPXY_USOK_2) {
470 			ftp->ftp_passok = FTPXY_PASS_2;
471 			ftp->ftp_incok = 1;
472 		}
473 	} else if ((ftp->ftp_passok == FTPXY_AUOK_1) &&
474 		   !strncmp(cmd, "ADAT ", 5)) {
475 		ftp->ftp_passok = FTPXY_ADAT_1;
476 		ftp->ftp_incok = 1;
477 	} else if ((ftp->ftp_passok == FTPXY_PAOK_1 ||
478 		    ftp->ftp_passok == FTPXY_PAOK_2) &&
479 		 !strncmp(cmd, "ACCT ", 5)) {
480 		ftp->ftp_passok = FTPXY_ACCT_1;
481 		ftp->ftp_incok = 1;
482 	} else if ((ftp->ftp_passok == FTPXY_GO) &&
483 		 !ifsftp->ippr_ftp_pasvonly &&
484 		 !strncmp(cmd, "PORT ", 5)) {
485 		inc = ippr_ftp_port(fin, ip, nat, f, dlen, ifsftp);
486 	} else if (ifsftp->ippr_ftp_insecure && !ifsftp->ippr_ftp_pasvonly &&
487 		   !strncmp(cmd, "PORT ", 5)) {
488 		inc = ippr_ftp_port(fin, ip, nat, f, dlen, ifsftp);
489 	}
490 
491 	while ((*rptr++ != '\n') && (rptr < wptr))
492 		;
493 	f->ftps_rptr = rptr;
494 	return inc;
495 }
496 
497 
ippr_ftp_pasv(fin,ip,nat,ftp,dlen,ifsftp)498 int ippr_ftp_pasv(fin, ip, nat, ftp, dlen, ifsftp)
499 fr_info_t *fin;
500 ip_t *ip;
501 nat_t *nat;
502 ftpinfo_t *ftp;
503 int dlen;
504 ifs_ftppxy_t *ifsftp;
505 {
506 	u_int a1, a2, a3, a4, data_ip;
507 	char newbuf[IPF_FTPBUFSZ];
508 	char *s, *brackets[2];
509 	u_short a5, a6;
510 	ftpside_t *f;
511 
512 	if (ifsftp->ippr_ftp_forcepasv != 0 &&
513 	    ftp->ftp_side[0].ftps_cmds != FTPXY_C_PASV) {
514 		if (ifsftp->ippr_ftp_debug > 0)
515 			printf("ippr_ftp_pasv:ftps_cmds(%d) != FTPXY_C_PASV\n",
516 			       ftp->ftp_side[0].ftps_cmds);
517 		return 0;
518 	}
519 
520 	f = &ftp->ftp_side[1];
521 
522 #define	PASV_REPLEN	24
523 	/*
524 	 * Check for PASV reply message.
525 	 */
526 	if (dlen < IPF_MIN227LEN) {
527 		if (ifsftp->ippr_ftp_debug > 1)
528 			printf("ippr_ftp_pasv:dlen(%d) < IPF_MIN227LEN\n",
529 			       dlen);
530 		return 0;
531 	} else if (strncmp(f->ftps_rptr,
532 			   "227 Entering Passive Mod", PASV_REPLEN)) {
533 		if (ifsftp->ippr_ftp_debug > 0)
534 			printf("ippr_ftp_pasv:%d reply wrong\n", 227);
535 		return 0;
536 	}
537 
538 	brackets[0] = "";
539 	brackets[1] = "";
540 	/*
541 	 * Skip the PASV reply + space
542 	 */
543 	s = f->ftps_rptr + PASV_REPLEN;
544 	while (*s && !ISDIGIT(*s)) {
545 		if (*s == '(') {
546 			brackets[0] = "(";
547 			brackets[1] = ")";
548 		}
549 		s++;
550 	}
551 
552 	/*
553 	 * Pick out the address components, two at a time.
554 	 */
555 	a1 = ippr_ftp_atoi(&s);
556 	if (s == NULL) {
557 		if (ifsftp->ippr_ftp_debug > 1)
558 			printf("ippr_ftp_pasv:ippr_ftp_atoi(%d) failed\n", 1);
559 		return 0;
560 	}
561 	a2 = ippr_ftp_atoi(&s);
562 	if (s == NULL) {
563 		if (ifsftp->ippr_ftp_debug > 1)
564 			printf("ippr_ftp_pasv:ippr_ftp_atoi(%d) failed\n", 2);
565 		return 0;
566 	}
567 
568 	/*
569 	 * check that IP address in the PASV reply is the same as the
570 	 * sender of the command - prevents using PASV for port scanning.
571 	 */
572 	a1 <<= 16;
573 	a1 |= a2;
574 
575 	if (((nat->nat_dir == NAT_INBOUND) &&
576 	     (a1 != ntohl(nat->nat_inip.s_addr))) ||
577 	    ((nat->nat_dir == NAT_OUTBOUND) &&
578 	     (a1 != ntohl(nat->nat_oip.s_addr)))) {
579 		if (ifsftp->ippr_ftp_debug > 0)
580 			printf("ippr_ftp_pasv:%s != nat->nat_oip\n", "a1");
581 		return 0;
582 	}
583 
584 	a5 = ippr_ftp_atoi(&s);
585 	if (s == NULL) {
586 		if (ifsftp->ippr_ftp_debug > 1)
587 			printf("ippr_ftp_pasv:ippr_ftp_atoi(%d) failed\n", 3);
588 		return 0;
589 	}
590 
591 	if (*s == ')')
592 		s++;
593 	if (*s == '.')
594 		s++;
595 	if (*s == '\n')
596 		s--;
597 	/*
598 	 * check for CR-LF at the end.
599 	 */
600 	if ((*s == '\r') && (*(s + 1) == '\n')) {
601 		s += 2;
602 	} else {
603 		if (ifsftp->ippr_ftp_debug > 1)
604 			printf("ippr_ftp_pasv:missing %s", "cr-lf\n");
605 		return 0;
606 	}
607 
608 	a6 = a5 & 0xff;
609 	a5 >>= 8;
610 	/*
611 	 * Calculate new address parts for 227 reply
612 	 */
613 	if (nat->nat_dir == NAT_INBOUND) {
614 		data_ip = nat->nat_outip.s_addr;
615 		a1 = ntohl(data_ip);
616 	} else
617 		data_ip = htonl(a1);
618 
619 	a2 = (a1 >> 16) & 0xff;
620 	a3 = (a1 >> 8) & 0xff;
621 	a4 = a1 & 0xff;
622 	a1 >>= 24;
623 
624 #if defined(SNPRINTF) && defined(_KERNEL)
625 	(void) SNPRINTF(newbuf, sizeof(newbuf), "%s %s%u,%u,%u,%u,%u,%u%s\r\n",
626 		"227 Entering Passive Mode", brackets[0], a1, a2, a3, a4,
627 		a5, a6, brackets[1]);
628 #else
629 	(void) sprintf(newbuf, "%s %s%u,%u,%u,%u,%u,%u%s\r\n",
630 		"227 Entering Passive Mode", brackets[0], a1, a2, a3, a4,
631 		a5, a6, brackets[1]);
632 #endif
633 	return ippr_ftp_pasvreply(fin, ip, nat, f, (a5 << 8 | a6),
634 				  newbuf, s, data_ip, ifsftp);
635 }
636 
ippr_ftp_pasvreply(fin,ip,nat,f,port,newmsg,s,data_ip,ifsftp)637 int ippr_ftp_pasvreply(fin, ip, nat, f, port, newmsg, s, data_ip, ifsftp)
638 fr_info_t *fin;
639 ip_t *ip;
640 nat_t *nat;
641 ftpside_t *f;
642 u_int port;
643 char *newmsg;
644 char *s;
645 u_int data_ip;
646 ifs_ftppxy_t *ifsftp;
647 {
648 	int inc, off, nflags, sflags;
649 	tcphdr_t *tcp, tcph, *tcp2;
650 	struct in_addr swip, swip2;
651 	struct in_addr data_addr;
652 	size_t nlen, olen;
653 	fr_info_t fi;
654 	nat_t *nat2;
655 	mb_t *m;
656 	ipf_stack_t *ifs = fin->fin_ifs;
657 
658 	m = fin->fin_m;
659 	tcp = (tcphdr_t *)fin->fin_dp;
660 	off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
661 
662 	data_addr.s_addr = data_ip;
663 	tcp2 = &tcph;
664 	inc = 0;
665 
666 
667 	olen = s - f->ftps_rptr;
668 	nlen = strlen(newmsg);
669 	inc = nlen - olen;
670 	if ((inc + ip->ip_len) > 65535) {
671 		if (ifsftp->ippr_ftp_debug > 0)
672 			printf("ippr_ftp_pasv:inc(%d) + ip->ip_len > 65535\n",
673 			       inc);
674 		return 0;
675 	}
676 
677 #if !defined(_KERNEL)
678 	bcopy(newmsg, MTOD(m, char *) + off, nlen);
679 #else
680 # if defined(MENTAT)
681 	if (inc < 0)
682 		(void)adjmsg(m, inc);
683 # else /* defined(MENTAT) */
684 	/*
685 	 * m_adj takes care of pkthdr.len, if required and treats inc<0 to
686 	 * mean remove -len bytes from the end of the packet.
687 	 * The mbuf chain will be extended if necessary by m_copyback().
688 	 */
689 	if (inc < 0)
690 		m_adj(m, inc);
691 # endif /* defined(MENTAT) */
692 #endif /* !defined(_KERNEL) */
693 	COPYBACK(m, off, nlen, newmsg);
694 
695 	if (inc != 0) {
696 		ip->ip_len += inc;
697 		fin->fin_dlen += inc;
698 		fin->fin_plen += inc;
699 	}
700 
701 	/*
702 	 * Add skeleton NAT entry for connection which will come back the
703 	 * other way.
704 	 */
705 	bcopy((char *)fin, (char *)&fi, sizeof(fi));
706 	fi.fin_flx |= FI_IGNORE;
707 	fi.fin_data[0] = 0;
708 	fi.fin_data[1] = port;
709 	nflags = IPN_TCP|SI_W_SPORT;
710 	if (ifsftp->ippr_ftp_pasvrdr && f->ftps_ifp)
711 		nflags |= SI_W_DPORT;
712 	if (nat->nat_dir == NAT_OUTBOUND)
713 		nat2 = nat_outlookup(&fi, nflags|NAT_SEARCH,
714 				     nat->nat_p, nat->nat_inip, nat->nat_oip);
715 	else
716 		nat2 = nat_inlookup(&fi, nflags|NAT_SEARCH,
717 				    nat->nat_p, nat->nat_inip, nat->nat_oip);
718 	if (nat2 == NULL) {
719 		int slen;
720 
721 		slen = ip->ip_len;
722 		ip->ip_len = fin->fin_hlen + sizeof(*tcp2);
723 		bzero((char *)tcp2, sizeof(*tcp2));
724 		tcp2->th_win = htons(8192);
725 		tcp2->th_sport = 0;		/* XXX - fake it for nat_new */
726 		TCP_OFF_A(tcp2, 5);
727 		tcp2->th_flags = TH_SYN;
728 		fi.fin_data[1] = port;
729 		fi.fin_dlen = sizeof(*tcp2);
730 		tcp2->th_dport = htons(port);
731 		fi.fin_data[0] = 0;
732 		fi.fin_dp = (char *)tcp2;
733 		fi.fin_plen = fi.fin_hlen + sizeof(*tcp);
734 		fi.fin_fr = &ifsftp->ftppxyfr;
735 		fi.fin_out = nat->nat_dir;
736 		fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE;
737 		swip = ip->ip_src;
738 		swip2 = ip->ip_dst;
739 		if (nat->nat_dir == NAT_OUTBOUND) {
740 			fi.fin_fi.fi_daddr = data_addr.s_addr;
741 			fi.fin_fi.fi_saddr = nat->nat_inip.s_addr;
742 			ip->ip_dst = data_addr;
743 			ip->ip_src = nat->nat_inip;
744 		} else if (nat->nat_dir == NAT_INBOUND) {
745 			fi.fin_fi.fi_saddr = nat->nat_oip.s_addr;
746 			fi.fin_fi.fi_daddr = nat->nat_outip.s_addr;
747 			ip->ip_src = nat->nat_oip;
748 			ip->ip_dst = nat->nat_outip;
749 		}
750 
751 		sflags = nflags;
752 		nflags |= NAT_SLAVE;
753 		if (nat->nat_dir == NAT_INBOUND)
754 			nflags |= NAT_NOTRULEPORT;
755 		nat2 = nat_new(&fi, nat->nat_ptr, NULL, nflags, nat->nat_dir);
756 		if (nat2 != NULL) {
757 			(void) nat_proto(&fi, nat2, IPN_TCP);
758 			nat_update(&fi, nat2, nat->nat_ptr);
759 			fi.fin_ifp = NULL;
760 			if (nat->nat_dir == NAT_INBOUND) {
761 				fi.fin_fi.fi_daddr = nat->nat_inip.s_addr;
762 				ip->ip_dst = nat->nat_inip;
763 			}
764 			(void) fr_addstate(&fi, &nat2->nat_state, sflags);
765 		}
766 
767 		ip->ip_len = slen;
768 		ip->ip_src = swip;
769 		ip->ip_dst = swip2;
770 	} else {
771 		ipstate_t *is;
772 
773 		nat_update(&fi, nat2, nat->nat_ptr);
774 		READ_ENTER(&ifs->ifs_ipf_state);
775 		is = nat2->nat_state;
776 		if (is != NULL) {
777 			MUTEX_ENTER(&is->is_lock);
778 			(void) fr_tcp_age(&is->is_sti, &fi, ifs->ifs_ips_tqtqb,
779 					  is->is_flags);
780 			MUTEX_EXIT(&is->is_lock);
781 		}
782 		RWLOCK_EXIT(&ifs->ifs_ipf_state);
783 	}
784 	return inc;
785 }
786 
787 
ippr_ftp_server(fin,ip,nat,ftp,dlen,ifsftp)788 int ippr_ftp_server(fin, ip, nat, ftp, dlen, ifsftp)
789 fr_info_t *fin;
790 ip_t *ip;
791 nat_t *nat;
792 ftpinfo_t *ftp;
793 int dlen;
794 ifs_ftppxy_t *ifsftp;
795 {
796 	char *rptr, *wptr;
797 	ftpside_t *f;
798 	int inc;
799 
800 	inc = 0;
801 	f = &ftp->ftp_side[1];
802 	rptr = f->ftps_rptr;
803 	wptr = f->ftps_wptr;
804 
805 	if (*rptr == ' ')
806 		goto server_cmd_ok;
807 	if (!ISDIGIT(*rptr) || !ISDIGIT(*(rptr + 1)) || !ISDIGIT(*(rptr + 2)))
808 		return 0;
809 	if (ftp->ftp_passok == FTPXY_GO) {
810 		if (!strncmp(rptr, "227 ", 4))
811 			inc = ippr_ftp_pasv(fin, ip, nat, ftp, dlen, ifsftp);
812 		else if (!strncmp(rptr, "229 ", 4))
813 			inc = ippr_ftp_epsv(fin, ip, nat, f, dlen, ifsftp);
814 	} else if (ifsftp->ippr_ftp_insecure && !strncmp(rptr, "227 ", 4)) {
815 		inc = ippr_ftp_pasv(fin, ip, nat, ftp, dlen, ifsftp);
816 	} else if (ifsftp->ippr_ftp_insecure && !strncmp(rptr, "229 ", 4)) {
817 		inc = ippr_ftp_epsv(fin, ip, nat, f, dlen, ifsftp);
818 	} else if (*rptr == '5' || *rptr == '4')
819 		ftp->ftp_passok = FTPXY_INIT;
820 	else if (ftp->ftp_incok) {
821 		if (*rptr == '3') {
822 			if (ftp->ftp_passok == FTPXY_ACCT_1)
823 				ftp->ftp_passok = FTPXY_GO;
824 			else
825 				ftp->ftp_passok++;
826 		} else if (*rptr == '2') {
827 			switch (ftp->ftp_passok)
828 			{
829 			case FTPXY_USER_1 :
830 			case FTPXY_USER_2 :
831 			case FTPXY_PASS_1 :
832 			case FTPXY_PASS_2 :
833 			case FTPXY_ACCT_1 :
834 				ftp->ftp_passok = FTPXY_GO;
835 				break;
836 			default :
837 				ftp->ftp_passok += 3;
838 				break;
839 			}
840 		}
841 	}
842 server_cmd_ok:
843 	ftp->ftp_incok = 0;
844 
845 	while ((*rptr++ != '\n') && (rptr < wptr))
846 		;
847 	f->ftps_rptr = rptr;
848 	return inc;
849 }
850 
851 
852 /*
853  * Look to see if the buffer starts with something which we recognise as
854  * being the correct syntax for the FTP protocol.
855  */
ippr_ftp_client_valid(ftps,buf,len,ifsftp)856 int ippr_ftp_client_valid(ftps, buf, len, ifsftp)
857 ftpside_t *ftps;
858 char *buf;
859 size_t len;
860 ifs_ftppxy_t *ifsftp;
861 {
862 	register char *s, c, pc;
863 	register size_t i = len;
864 	char cmd[5];
865 
866 	s = buf;
867 
868 	if (ftps->ftps_junk == 1)
869 		return 1;
870 
871 	if (i < 5) {
872 		if (ifsftp->ippr_ftp_debug > 3)
873 			printf("ippr_ftp_client_valid:i(%d) < 5\n", (int)i);
874 		return 2;
875 	}
876 
877 	i--;
878 	c = *s++;
879 
880 	if (ISALPHA(c)) {
881 		cmd[0] = TOUPPER(c);
882 		c = *s++;
883 		i--;
884 		if (ISALPHA(c)) {
885 			cmd[1] = TOUPPER(c);
886 			c = *s++;
887 			i--;
888 			if (ISALPHA(c)) {
889 				cmd[2] = TOUPPER(c);
890 				c = *s++;
891 				i--;
892 				if (ISALPHA(c)) {
893 					cmd[3] = TOUPPER(c);
894 					c = *s++;
895 					i--;
896 					if ((c != ' ') && (c != '\r'))
897 						goto bad_client_command;
898 				} else if ((c != ' ') && (c != '\r'))
899 					goto bad_client_command;
900 			} else
901 				goto bad_client_command;
902 		} else
903 			goto bad_client_command;
904 	} else {
905 bad_client_command:
906 		if (ifsftp->ippr_ftp_debug > 3)
907 			printf("%s:bad:junk %d len %d/%d c 0x%x buf [%*s]\n",
908 			       "ippr_ftp_client_valid",
909 			       ftps->ftps_junk, (int)len, (int)i, c,
910 			       (int)len, buf);
911 		return 1;
912 	}
913 
914 	for (; i; i--) {
915 		pc = c;
916 		c = *s++;
917 		if ((pc == '\r') && (c == '\n')) {
918 			cmd[4] = '\0';
919 			if (!strcmp(cmd, "PASV"))
920 				ftps->ftps_cmds = FTPXY_C_PASV;
921 			else
922 				ftps->ftps_cmds = 0;
923 			return 0;
924 		}
925 	}
926 #if !defined(_KERNEL)
927 	printf("ippr_ftp_client_valid:junk after cmd[%*.*s]\n",
928 	       (int)len, (int)len, buf);
929 #endif
930 	return 2;
931 }
932 
933 
ippr_ftp_server_valid(ftps,buf,len,ifsftp)934 int ippr_ftp_server_valid(ftps, buf, len, ifsftp)
935 ftpside_t *ftps;
936 char *buf;
937 size_t len;
938 ifs_ftppxy_t *ifsftp;
939 {
940 	register char *s, c, pc;
941 	register size_t i = len;
942 	int cmd;
943 
944 	s = buf;
945 	cmd = 0;
946 
947 	if (ftps->ftps_junk == 1)
948 		return 1;
949 
950 	if (i < 5) {
951 		if (ifsftp->ippr_ftp_debug > 3)
952 			printf("ippr_ftp_servert_valid:i(%d) < 5\n", (int)i);
953 		return 2;
954 	}
955 
956 	c = *s++;
957 	i--;
958 	if (c == ' ')
959 		goto search_eol;
960 
961 	if (ISDIGIT(c)) {
962 		cmd = (c - '0') * 100;
963 		c = *s++;
964 		i--;
965 		if (ISDIGIT(c)) {
966 			cmd += (c - '0') * 10;
967 			c = *s++;
968 			i--;
969 			if (ISDIGIT(c)) {
970 				cmd += (c - '0');
971 				c = *s++;
972 				i--;
973 				if ((c != '-') && (c != ' '))
974 					goto bad_server_command;
975 			} else
976 				goto bad_server_command;
977 		} else
978 			goto bad_server_command;
979 	} else {
980 bad_server_command:
981 		if (ifsftp->ippr_ftp_debug > 3)
982 			printf("%s:bad:junk %d len %d/%d c 0x%x buf [%*s]\n",
983 			       "ippr_ftp_server_valid",
984 			       ftps->ftps_junk, (int)len, (int)i,
985 			       c, (int)len, buf);
986 		return 1;
987 	}
988 search_eol:
989 	for (; i; i--) {
990 		pc = c;
991 		c = *s++;
992 		if ((pc == '\r') && (c == '\n')) {
993 			ftps->ftps_cmds = cmd;
994 			return 0;
995 		}
996 	}
997 	if (ifsftp->ippr_ftp_debug > 3)
998 		printf("ippr_ftp_server_valid:junk after cmd[%*s]\n",
999 		       (int)len, buf);
1000 	return 2;
1001 }
1002 
1003 
ippr_ftp_valid(ftp,side,buf,len,ifsftp)1004 int ippr_ftp_valid(ftp, side, buf, len, ifsftp)
1005 ftpinfo_t *ftp;
1006 int side;
1007 char *buf;
1008 size_t len;
1009 ifs_ftppxy_t *ifsftp;
1010 {
1011 	ftpside_t *ftps;
1012 	int ret;
1013 
1014 	ftps = &ftp->ftp_side[side];
1015 
1016 	if (side == 0)
1017 		ret = ippr_ftp_client_valid(ftps, buf, len, ifsftp);
1018 	else
1019 		ret = ippr_ftp_server_valid(ftps, buf, len, ifsftp);
1020 	return ret;
1021 }
1022 
1023 
1024 /*
1025  * For map rules, the following applies:
1026  * rv == 0 for outbound processing,
1027  * rv == 1 for inbound processing.
1028  * For rdr rules, the following applies:
1029  * rv == 0 for inbound processing,
1030  * rv == 1 for outbound processing.
1031  */
ippr_ftp_process(fin,nat,ftp,rv,ifsftp)1032 int ippr_ftp_process(fin, nat, ftp, rv, ifsftp)
1033 fr_info_t *fin;
1034 nat_t *nat;
1035 ftpinfo_t *ftp;
1036 int rv;
1037 ifs_ftppxy_t *ifsftp;
1038 {
1039 	int mlen, len, off, inc, i, sel, sel2, ok, ackoff, seqoff;
1040 	char *rptr, *wptr, *s;
1041 	u_32_t thseq, thack;
1042 	ap_session_t *aps;
1043 	ftpside_t *f, *t;
1044 	tcphdr_t *tcp;
1045 	ip_t *ip;
1046 	mb_t *m;
1047 
1048 	m = fin->fin_m;
1049 	ip = fin->fin_ip;
1050 	tcp = (tcphdr_t *)fin->fin_dp;
1051 	off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
1052 
1053 	f = &ftp->ftp_side[rv];
1054 	t = &ftp->ftp_side[1 - rv];
1055 	thseq = ntohl(tcp->th_seq);
1056 	thack = ntohl(tcp->th_ack);
1057 
1058 #ifdef __sgi
1059 	mlen = fin->fin_plen - off;
1060 #else
1061 	mlen = MSGDSIZE(m) - off;
1062 #endif
1063 	if (ifsftp->ippr_ftp_debug > 4)
1064 		printf("ippr_ftp_process: mlen %d\n", mlen);
1065 
1066 	if (mlen <= 0) {
1067 		if ((tcp->th_flags & TH_OPENING) == TH_OPENING) {
1068 			f->ftps_seq[0] = thseq + 1;
1069 			t->ftps_seq[0] = thack;
1070 		}
1071 		return 0;
1072 	}
1073 	aps = nat->nat_aps;
1074 
1075 	sel = aps->aps_sel[1 - rv];
1076 	sel2 = aps->aps_sel[rv];
1077 	if (rv == 0) {
1078 		seqoff = aps->aps_seqoff[sel];
1079 		if (aps->aps_seqmin[sel] > seqoff + thseq)
1080 			seqoff = aps->aps_seqoff[!sel];
1081 		ackoff = aps->aps_ackoff[sel2];
1082 		if (aps->aps_ackmin[sel2] > ackoff + thack)
1083 			ackoff = aps->aps_ackoff[!sel2];
1084 	} else {
1085 		seqoff = aps->aps_ackoff[sel];
1086 		if (ifsftp->ippr_ftp_debug > 2)
1087 			printf("seqoff %d thseq %x ackmin %x\n", seqoff, thseq,
1088 			       aps->aps_ackmin[sel]);
1089 		if (aps->aps_ackmin[sel] > seqoff + thseq)
1090 			seqoff = aps->aps_ackoff[!sel];
1091 
1092 		ackoff = aps->aps_seqoff[sel2];
1093 		if (ifsftp->ippr_ftp_debug > 2)
1094 			printf("ackoff %d thack %x seqmin %x\n", ackoff, thack,
1095 			       aps->aps_seqmin[sel2]);
1096 		if (ackoff > 0) {
1097 			if (aps->aps_seqmin[sel2] > ackoff + thack)
1098 				ackoff = aps->aps_seqoff[!sel2];
1099 		} else {
1100 			if (aps->aps_seqmin[sel2] > thack)
1101 				ackoff = aps->aps_seqoff[!sel2];
1102 		}
1103 	}
1104 	if (ifsftp->ippr_ftp_debug > 2) {
1105 		printf("%s: %x seq %x/%d ack %x/%d len %d/%d off %d\n",
1106 		       rv ? "IN" : "OUT", tcp->th_flags, thseq, seqoff,
1107 		       thack, ackoff, mlen, fin->fin_plen, off);
1108 		printf("sel %d seqmin %x/%x offset %d/%d\n", sel,
1109 		       aps->aps_seqmin[sel], aps->aps_seqmin[sel2],
1110 		       aps->aps_seqoff[sel], aps->aps_seqoff[sel2]);
1111 		printf("sel %d ackmin %x/%x offset %d/%d\n", sel2,
1112 		       aps->aps_ackmin[sel], aps->aps_ackmin[sel2],
1113 		       aps->aps_ackoff[sel], aps->aps_ackoff[sel2]);
1114 	}
1115 
1116 	/*
1117 	 * XXX - Ideally, this packet should get dropped because we now know
1118 	 * that it is out of order (and there is no real danger in doing so
1119 	 * apart from causing packets to go through here ordered).
1120 	 */
1121 	if (ifsftp->ippr_ftp_debug > 2) {
1122 		printf("rv %d t:seq[0] %x seq[1] %x %d/%d\n",
1123 		       rv, t->ftps_seq[0], t->ftps_seq[1], seqoff, ackoff);
1124 	}
1125 
1126 	ok = 0;
1127 	if (t->ftps_seq[0] == 0) {
1128 		t->ftps_seq[0] = thack;
1129 		ok = 1;
1130 	} else {
1131 		if (ackoff == 0) {
1132 			if (t->ftps_seq[0] == thack)
1133 				ok = 1;
1134 			else if (t->ftps_seq[1] == thack) {
1135 				t->ftps_seq[0] = thack;
1136 				ok = 1;
1137 			}
1138 		} else {
1139 			if (t->ftps_seq[0] + ackoff == thack)
1140 				ok = 1;
1141 			else if (t->ftps_seq[0] == thack + ackoff)
1142 				ok = 1;
1143 			else if (t->ftps_seq[1] + ackoff == thack) {
1144 				t->ftps_seq[0] = thack - ackoff;
1145 				ok = 1;
1146 			} else if (t->ftps_seq[1] == thack + ackoff) {
1147 				t->ftps_seq[0] = thack - ackoff;
1148 				ok = 1;
1149 			}
1150 		}
1151 	}
1152 
1153 	if (ifsftp->ippr_ftp_debug > 2) {
1154 		if (!ok)
1155 			printf("%s ok\n", "not");
1156 	}
1157 
1158 	if (!mlen) {
1159 		if (t->ftps_seq[0] + ackoff != thack) {
1160 			if (ifsftp->ippr_ftp_debug > 1) {
1161 				printf("%s:seq[0](%x) + (%x) != (%x)\n",
1162 				       "ippr_ftp_process", t->ftps_seq[0],
1163 				       ackoff, thack);
1164 			}
1165 			return APR_ERR(1);
1166 		}
1167 
1168 		if (ifsftp->ippr_ftp_debug > 2) {
1169 			printf("ippr_ftp_process:f:seq[0] %x seq[1] %x\n",
1170 				f->ftps_seq[0], f->ftps_seq[1]);
1171 		}
1172 
1173 		if (tcp->th_flags & TH_FIN) {
1174 			if (thseq == f->ftps_seq[1]) {
1175 				f->ftps_seq[0] = f->ftps_seq[1] - seqoff;
1176 				f->ftps_seq[1] = thseq + 1 - seqoff;
1177 			} else {
1178 				if (ifsftp->ippr_ftp_debug > 1) {
1179 					printf("FIN: thseq %x seqoff %d ftps_seq %x\n",
1180 					       thseq, seqoff, f->ftps_seq[0]);
1181 				}
1182 				return APR_ERR(1);
1183 			}
1184 		}
1185 		f->ftps_len = 0;
1186 		return 0;
1187 	}
1188 
1189 	ok = 0;
1190 	if ((thseq == f->ftps_seq[0]) || (thseq == f->ftps_seq[1])) {
1191 		ok = 1;
1192 	/*
1193 	 * Retransmitted data packet.
1194 	 */
1195 	} else if ((thseq + mlen == f->ftps_seq[0]) ||
1196 		   (thseq + mlen == f->ftps_seq[1])) {
1197 		ok = 1;
1198 	}
1199 
1200 	if (ok == 0) {
1201 		inc = thseq - f->ftps_seq[0];
1202 		if (ifsftp->ippr_ftp_debug > 1) {
1203 			printf("inc %d sel %d rv %d\n", inc, sel, rv);
1204 			printf("th_seq %x ftps_seq %x/%x\n",
1205 			       thseq, f->ftps_seq[0], f->ftps_seq[1]);
1206 			printf("ackmin %x ackoff %d\n", aps->aps_ackmin[sel],
1207 			       aps->aps_ackoff[sel]);
1208 			printf("seqmin %x seqoff %d\n", aps->aps_seqmin[sel],
1209 			       aps->aps_seqoff[sel]);
1210 		}
1211 
1212 		return APR_ERR(1);
1213 	}
1214 
1215 	inc = 0;
1216 	rptr = f->ftps_rptr;
1217 	wptr = f->ftps_wptr;
1218 	f->ftps_seq[0] = thseq;
1219 	f->ftps_seq[1] = f->ftps_seq[0] + mlen;
1220 	f->ftps_len = mlen;
1221 
1222 	while (mlen > 0) {
1223 		len = MIN(mlen, sizeof(f->ftps_buf) - (wptr - rptr));
1224 		COPYDATA(m, off, len, wptr);
1225 		mlen -= len;
1226 		off += len;
1227 		wptr += len;
1228 
1229 		if (ifsftp->ippr_ftp_debug > 3)
1230 			printf("%s:len %d/%d off %d wptr %lx junk %d [%*s]\n",
1231 			       "ippr_ftp_process",
1232 			       len, mlen, off, (u_long)wptr, f->ftps_junk,
1233 			       len, rptr);
1234 
1235 		f->ftps_wptr = wptr;
1236 		if (f->ftps_junk != 0) {
1237 			i = f->ftps_junk;
1238 			f->ftps_junk = ippr_ftp_valid(ftp, rv, rptr,
1239 						      wptr - rptr, ifsftp);
1240 
1241 			if (ifsftp->ippr_ftp_debug > 5)
1242 				printf("%s:junk %d -> %d\n",
1243 				       "ippr_ftp_process", i, f->ftps_junk);
1244 
1245 			if (f->ftps_junk != 0) {
1246 				if (wptr - rptr == sizeof(f->ftps_buf)) {
1247 					if (ifsftp->ippr_ftp_debug > 4)
1248 						printf("%s:full buffer\n",
1249 						       "ippr_ftp_process");
1250 					f->ftps_rptr = f->ftps_buf;
1251 					f->ftps_wptr = f->ftps_buf;
1252 					rptr = f->ftps_rptr;
1253 					wptr = f->ftps_wptr;
1254 					/*
1255 					 * Because we throw away data here that
1256 					 * we would otherwise parse, set the
1257 					 * junk flag to indicate just ignore
1258 					 * any data upto the next CRLF.
1259 					 */
1260 					f->ftps_junk = 1;
1261 					continue;
1262 				}
1263 			}
1264 		}
1265 
1266 		while ((f->ftps_junk == 0) && (wptr > rptr)) {
1267 			len = wptr - rptr;
1268 			f->ftps_junk = ippr_ftp_valid(ftp, rv, rptr, len, ifsftp);
1269 
1270 			if (ifsftp->ippr_ftp_debug > 3) {
1271 				printf("%s=%d len %d rv %d ptr %lx/%lx ",
1272 				       "ippr_ftp_valid",
1273 				       f->ftps_junk, len, rv, (u_long)rptr,
1274 				       (u_long)wptr);
1275 				printf("buf [%*s]\n", len, rptr);
1276 			}
1277 
1278 			if (f->ftps_junk == 0) {
1279 				f->ftps_rptr = rptr;
1280 				if (rv)
1281 					inc += ippr_ftp_server(fin, ip, nat,
1282 							       ftp, len, ifsftp);
1283 				else
1284 					inc += ippr_ftp_client(fin, ip, nat,
1285 							       ftp, len, ifsftp);
1286 				rptr = f->ftps_rptr;
1287 				wptr = f->ftps_wptr;
1288 			}
1289 		}
1290 
1291 		/*
1292 		 * Off to a bad start so lets just forget about using the
1293 		 * ftp proxy for this connection.
1294 		 */
1295 		if ((f->ftps_cmds == 0) && (f->ftps_junk == 1)) {
1296 			/* f->ftps_seq[1] += inc; */
1297 
1298 			if (ifsftp->ippr_ftp_debug > 1)
1299 				printf("%s:cmds == 0 junk == 1\n",
1300 				       "ippr_ftp_process");
1301 			return APR_ERR(2);
1302 		}
1303 
1304 		if ((f->ftps_junk != 0) && (rptr < wptr)) {
1305 			for (s = rptr; s < wptr; s++) {
1306 				if ((*s == '\r') && (s + 1 < wptr) &&
1307 				    (*(s + 1) == '\n')) {
1308 					rptr = s + 2;
1309 					f->ftps_junk = 0;
1310 					break;
1311 				}
1312 			}
1313 		}
1314 
1315 		if (rptr == wptr) {
1316 			rptr = wptr = f->ftps_buf;
1317 		} else {
1318 			/*
1319 			 * Compact the buffer back to the start.  The junk
1320 			 * flag should already be set and because we're not
1321 			 * throwing away any data, it is preserved from its
1322 			 * current state.
1323 			 */
1324 			if (rptr > f->ftps_buf) {
1325 				bcopy(rptr, f->ftps_buf, len);
1326 				wptr -= rptr - f->ftps_buf;
1327 				rptr = f->ftps_buf;
1328 			}
1329 		}
1330 		f->ftps_rptr = rptr;
1331 		f->ftps_wptr = wptr;
1332 	}
1333 
1334 	/* f->ftps_seq[1] += inc; */
1335 	if (tcp->th_flags & TH_FIN)
1336 		f->ftps_seq[1]++;
1337 	if (ifsftp->ippr_ftp_debug > 3) {
1338 #ifdef __sgi
1339 		mlen = fin->fin_plen;
1340 #else
1341 		mlen = MSGDSIZE(m);
1342 #endif
1343 		mlen -= off;
1344 		printf("ftps_seq[1] = %x inc %d len %d\n",
1345 		       f->ftps_seq[1], inc, mlen);
1346 	}
1347 
1348 	f->ftps_rptr = rptr;
1349 	f->ftps_wptr = wptr;
1350 	return APR_INC(inc);
1351 }
1352 
1353 
ippr_ftp_out(fin,aps,nat,private)1354 int ippr_ftp_out(fin, aps, nat, private)
1355 fr_info_t *fin;
1356 ap_session_t *aps;
1357 nat_t *nat;
1358 void *private;
1359 {
1360 	ftpinfo_t *ftp;
1361 	int rev;
1362 
1363 	ftp = aps->aps_data;
1364 	if (ftp == NULL)
1365 		return 0;
1366 
1367 	rev = (nat->nat_dir == NAT_OUTBOUND) ? 0 : 1;
1368 	if (ftp->ftp_side[1 - rev].ftps_ifp == NULL)
1369 		ftp->ftp_side[1 - rev].ftps_ifp = fin->fin_ifp;
1370 
1371 	return ippr_ftp_process(fin, nat, ftp, rev, (ifs_ftppxy_t *)private);
1372 }
1373 
1374 
ippr_ftp_in(fin,aps,nat,private)1375 int ippr_ftp_in(fin, aps, nat, private)
1376 fr_info_t *fin;
1377 ap_session_t *aps;
1378 nat_t *nat;
1379 void *private;
1380 {
1381 	ftpinfo_t *ftp;
1382 	int rev;
1383 
1384 	ftp = aps->aps_data;
1385 	if (ftp == NULL)
1386 		return 0;
1387 
1388 	rev = (nat->nat_dir == NAT_OUTBOUND) ? 0 : 1;
1389 	if (ftp->ftp_side[rev].ftps_ifp == NULL)
1390 		ftp->ftp_side[rev].ftps_ifp = fin->fin_ifp;
1391 
1392 	return ippr_ftp_process(fin, nat, ftp, 1 - rev, (ifs_ftppxy_t *)private);
1393 }
1394 
1395 
1396 /*
1397  * ippr_ftp_atoi - implement a version of atoi which processes numbers in
1398  * pairs separated by commas (which are expected to be in the range 0 - 255),
1399  * returning a 16 bit number combining either side of the , as the MSB and
1400  * LSB.
1401  */
ippr_ftp_atoi(ptr)1402 u_short ippr_ftp_atoi(ptr)
1403 char **ptr;
1404 {
1405 	register char *s = *ptr, c;
1406 	register u_char i = 0, j = 0;
1407 
1408 	while (((c = *s++) != '\0') && ISDIGIT(c)) {
1409 		i *= 10;
1410 		i += c - '0';
1411 	}
1412 	if (c != ',') {
1413 		*ptr = NULL;
1414 		return 0;
1415 	}
1416 	while (((c = *s++) != '\0') && ISDIGIT(c)) {
1417 		j *= 10;
1418 		j += c - '0';
1419 	}
1420 	*ptr = s;
1421 	i &= 0xff;
1422 	j &= 0xff;
1423 	return (i << 8) | j;
1424 }
1425 
1426 
ippr_ftp_epsv(fin,ip,nat,f,dlen,ifsftp)1427 int ippr_ftp_epsv(fin, ip, nat, f, dlen, ifsftp)
1428 fr_info_t *fin;
1429 ip_t *ip;
1430 nat_t *nat;
1431 ftpside_t *f;
1432 int dlen;
1433 ifs_ftppxy_t *ifsftp;
1434 {
1435 	char newbuf[IPF_FTPBUFSZ];
1436 	char *s;
1437 	u_short ap = 0;
1438 
1439 #define EPSV_REPLEN	33
1440 	/*
1441 	 * Check for EPSV reply message.
1442 	 */
1443 	if (dlen < IPF_MIN229LEN)
1444 		return (0);
1445 	else if (strncmp(f->ftps_rptr,
1446 			 "229 Entering Extended Passive Mode", EPSV_REPLEN))
1447 		return (0);
1448 
1449 	/*
1450 	 * Skip the EPSV command + space
1451 	 */
1452 	s = f->ftps_rptr + 33;
1453 	while (*s && !ISDIGIT(*s))
1454 		s++;
1455 
1456 	/*
1457 	 * As per RFC 2428, there are no addres components in the EPSV
1458 	 * response.  So we'll go straight to getting the port.
1459 	 */
1460 	while (*s && ISDIGIT(*s)) {
1461 		ap *= 10;
1462 		ap += *s++ - '0';
1463 	}
1464 
1465 	if (!s)
1466 		return 0;
1467 
1468 	if (*s == '|')
1469 		s++;
1470 	if (*s == ')')
1471 		s++;
1472 	if (*s == '\n')
1473 		s--;
1474 	/*
1475 	 * check for CR-LF at the end.
1476 	 */
1477 	if ((*s == '\r') && (*(s + 1) == '\n')) {
1478 		s += 2;
1479 	} else
1480 		return 0;
1481 
1482 #if defined(SNPRINTF) && defined(_KERNEL)
1483 	(void) SNPRINTF(newbuf, sizeof(newbuf), "%s (|||%u|)\r\n",
1484 		 "229 Entering Extended Passive Mode", ap);
1485 #else
1486 	(void) sprintf(newbuf, "%s (|||%u|)\r\n",
1487 		       "229 Entering Extended Passive Mode", ap);
1488 #endif
1489 
1490 	return ippr_ftp_pasvreply(fin, ip, nat, f, (u_int)ap, newbuf, s,
1491 				  ip->ip_src.s_addr, ifsftp);
1492 }
1493