1 /*-
2 * Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
23 * SUCH DAMAGE.
24 */
25
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28
29 /*
30 * The FreeBSD IP packet firewall, main file
31 */
32
33 #include "opt_ipfw.h"
34 #include "opt_ipdivert.h"
35 #include "opt_inet.h"
36 #ifndef INET
37 #error "IPFIREWALL requires INET"
38 #endif /* INET */
39 #include "opt_inet6.h"
40 #include "opt_ipsec.h"
41
42 #include <sys/param.h>
43 #include <sys/systm.h>
44 #include <sys/condvar.h>
45 #include <sys/counter.h>
46 #include <sys/eventhandler.h>
47 #include <sys/malloc.h>
48 #include <sys/mbuf.h>
49 #include <sys/kernel.h>
50 #include <sys/lock.h>
51 #include <sys/jail.h>
52 #include <sys/module.h>
53 #include <sys/priv.h>
54 #include <sys/proc.h>
55 #include <sys/rwlock.h>
56 #include <sys/rmlock.h>
57 #include <sys/socket.h>
58 #include <sys/socketvar.h>
59 #include <sys/sysctl.h>
60 #include <sys/syslog.h>
61 #include <sys/ucred.h>
62 #include <net/ethernet.h> /* for ETHERTYPE_IP */
63 #include <net/if.h>
64 #include <net/if_var.h>
65 #include <net/route.h>
66 #include <net/pfil.h>
67 #include <net/vnet.h>
68
69 #include <netpfil/pf/pf_mtag.h>
70
71 #include <netinet/in.h>
72 #include <netinet/in_var.h>
73 #include <netinet/in_pcb.h>
74 #include <netinet/ip.h>
75 #include <netinet/ip_var.h>
76 #include <netinet/ip_icmp.h>
77 #include <netinet/ip_fw.h>
78 #include <netinet/ip_carp.h>
79 #include <netinet/pim.h>
80 #include <netinet/tcp_var.h>
81 #include <netinet/udp.h>
82 #include <netinet/udp_var.h>
83 #include <netinet/sctp.h>
84
85 #include <netinet/ip6.h>
86 #include <netinet/icmp6.h>
87 #include <netinet/in_fib.h>
88 #ifdef INET6
89 #include <netinet6/in6_fib.h>
90 #include <netinet6/in6_pcb.h>
91 #include <netinet6/scope6_var.h>
92 #include <netinet6/ip6_var.h>
93 #endif
94
95 #include <netpfil/ipfw/ip_fw_private.h>
96
97 #include <machine/in_cksum.h> /* XXX for in_cksum */
98
99 #ifdef MAC
100 #include <security/mac/mac_framework.h>
101 #endif
102
103 /*
104 * static variables followed by global ones.
105 * All ipfw global variables are here.
106 */
107
108 static VNET_DEFINE(int, fw_deny_unknown_exthdrs);
109 #define V_fw_deny_unknown_exthdrs VNET(fw_deny_unknown_exthdrs)
110
111 static VNET_DEFINE(int, fw_permit_single_frag6) = 1;
112 #define V_fw_permit_single_frag6 VNET(fw_permit_single_frag6)
113
114 #ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
115 static int default_to_accept = 1;
116 #else
117 static int default_to_accept;
118 #endif
119
120 VNET_DEFINE(int, autoinc_step);
121 VNET_DEFINE(int, fw_one_pass) = 1;
122
123 VNET_DEFINE(unsigned int, fw_tables_max);
124 VNET_DEFINE(unsigned int, fw_tables_sets) = 0; /* Don't use set-aware tables */
125 /* Use 128 tables by default */
126 static unsigned int default_fw_tables = IPFW_TABLES_DEFAULT;
127
128 #ifndef LINEAR_SKIPTO
129 static int jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num,
130 int tablearg, int jump_backwards);
131 #define JUMP(ch, f, num, targ, back) jump_fast(ch, f, num, targ, back)
132 #else
133 static int jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num,
134 int tablearg, int jump_backwards);
135 #define JUMP(ch, f, num, targ, back) jump_linear(ch, f, num, targ, back)
136 #endif
137
138 /*
139 * Each rule belongs to one of 32 different sets (0..31).
140 * The variable set_disable contains one bit per set.
141 * If the bit is set, all rules in the corresponding set
142 * are disabled. Set RESVD_SET(31) is reserved for the default rule
143 * and rules that are not deleted by the flush command,
144 * and CANNOT be disabled.
145 * Rules in set RESVD_SET can only be deleted individually.
146 */
147 VNET_DEFINE(u_int32_t, set_disable);
148 #define V_set_disable VNET(set_disable)
149
150 VNET_DEFINE(int, fw_verbose);
151 /* counter for ipfw_log(NULL...) */
152 VNET_DEFINE(u_int64_t, norule_counter);
153 VNET_DEFINE(int, verbose_limit);
154
155 /* layer3_chain contains the list of rules for layer 3 */
156 VNET_DEFINE(struct ip_fw_chain, layer3_chain);
157
158 /* ipfw_vnet_ready controls when we are open for business */
159 VNET_DEFINE(int, ipfw_vnet_ready) = 0;
160
161 VNET_DEFINE(int, ipfw_nat_ready) = 0;
162
163 ipfw_nat_t *ipfw_nat_ptr = NULL;
164 struct cfg_nat *(*lookup_nat_ptr)(struct nat_list *, int);
165 ipfw_nat_cfg_t *ipfw_nat_cfg_ptr;
166 ipfw_nat_cfg_t *ipfw_nat_del_ptr;
167 ipfw_nat_cfg_t *ipfw_nat_get_cfg_ptr;
168 ipfw_nat_cfg_t *ipfw_nat_get_log_ptr;
169
170 #ifdef SYSCTL_NODE
171 uint32_t dummy_def = IPFW_DEFAULT_RULE;
172 static int sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS);
173 static int sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS);
174
175 SYSBEGIN(f3)
176
177 SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
178 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass,
179 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_one_pass), 0,
180 "Only do a single pass through ipfw when using dummynet(4)");
181 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step,
182 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(autoinc_step), 0,
183 "Rule number auto-increment step");
184 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose,
185 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE3, &VNET_NAME(fw_verbose), 0,
186 "Log matches to ipfw rules");
187 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit,
188 CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(verbose_limit), 0,
189 "Set upper limit of matches of ipfw rules logged");
190 SYSCTL_UINT(_net_inet_ip_fw, OID_AUTO, default_rule, CTLFLAG_RD,
191 &dummy_def, 0,
192 "The default/max possible rule number.");
193 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_max,
194 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW, 0, 0, sysctl_ipfw_table_num, "IU",
195 "Maximum number of concurrently used tables");
196 SYSCTL_PROC(_net_inet_ip_fw, OID_AUTO, tables_sets,
197 CTLFLAG_VNET | CTLTYPE_UINT | CTLFLAG_RW,
198 0, 0, sysctl_ipfw_tables_sets, "IU",
199 "Use per-set namespace for tables");
200 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, default_to_accept, CTLFLAG_RDTUN,
201 &default_to_accept, 0,
202 "Make the default rule accept all packets.");
203 TUNABLE_INT("net.inet.ip.fw.tables_max", (int *)&default_fw_tables);
204 SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count,
205 CTLFLAG_VNET | CTLFLAG_RD, &VNET_NAME(layer3_chain.n_rules), 0,
206 "Number of static rules");
207
208 #ifdef INET6
209 SYSCTL_DECL(_net_inet6_ip6);
210 SYSCTL_NODE(_net_inet6_ip6, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
211 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, deny_unknown_exthdrs,
212 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE,
213 &VNET_NAME(fw_deny_unknown_exthdrs), 0,
214 "Deny packets with unknown IPv6 Extension Headers");
215 SYSCTL_INT(_net_inet6_ip6_fw, OID_AUTO, permit_single_frag6,
216 CTLFLAG_VNET | CTLFLAG_RW | CTLFLAG_SECURE,
217 &VNET_NAME(fw_permit_single_frag6), 0,
218 "Permit single packet IPv6 fragments");
219 #endif /* INET6 */
220
221 SYSEND
222
223 #endif /* SYSCTL_NODE */
224
225
226 /*
227 * Some macros used in the various matching options.
228 * L3HDR maps an ipv4 pointer into a layer3 header pointer of type T
229 * Other macros just cast void * into the appropriate type
230 */
231 #define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl))
232 #define TCP(p) ((struct tcphdr *)(p))
233 #define SCTP(p) ((struct sctphdr *)(p))
234 #define UDP(p) ((struct udphdr *)(p))
235 #define ICMP(p) ((struct icmphdr *)(p))
236 #define ICMP6(p) ((struct icmp6_hdr *)(p))
237
238 static __inline int
icmptype_match(struct icmphdr * icmp,ipfw_insn_u32 * cmd)239 icmptype_match(struct icmphdr *icmp, ipfw_insn_u32 *cmd)
240 {
241 int type = icmp->icmp_type;
242
243 return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) );
244 }
245
246 #define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \
247 (1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) )
248
249 static int
is_icmp_query(struct icmphdr * icmp)250 is_icmp_query(struct icmphdr *icmp)
251 {
252 int type = icmp->icmp_type;
253
254 return (type <= ICMP_MAXTYPE && (TT & (1<<type)) );
255 }
256 #undef TT
257
258 /*
259 * The following checks use two arrays of 8 or 16 bits to store the
260 * bits that we want set or clear, respectively. They are in the
261 * low and high half of cmd->arg1 or cmd->d[0].
262 *
263 * We scan options and store the bits we find set. We succeed if
264 *
265 * (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
266 *
267 * The code is sometimes optimized not to store additional variables.
268 */
269
270 static int
flags_match(ipfw_insn * cmd,u_int8_t bits)271 flags_match(ipfw_insn *cmd, u_int8_t bits)
272 {
273 u_char want_clear;
274 bits = ~bits;
275
276 if ( ((cmd->arg1 & 0xff) & bits) != 0)
277 return 0; /* some bits we want set were clear */
278 want_clear = (cmd->arg1 >> 8) & 0xff;
279 if ( (want_clear & bits) != want_clear)
280 return 0; /* some bits we want clear were set */
281 return 1;
282 }
283
284 static int
ipopts_match(struct ip * ip,ipfw_insn * cmd)285 ipopts_match(struct ip *ip, ipfw_insn *cmd)
286 {
287 int optlen, bits = 0;
288 u_char *cp = (u_char *)(ip + 1);
289 int x = (ip->ip_hl << 2) - sizeof (struct ip);
290
291 for (; x > 0; x -= optlen, cp += optlen) {
292 int opt = cp[IPOPT_OPTVAL];
293
294 if (opt == IPOPT_EOL)
295 break;
296 if (opt == IPOPT_NOP)
297 optlen = 1;
298 else {
299 optlen = cp[IPOPT_OLEN];
300 if (optlen <= 0 || optlen > x)
301 return 0; /* invalid or truncated */
302 }
303 switch (opt) {
304
305 default:
306 break;
307
308 case IPOPT_LSRR:
309 bits |= IP_FW_IPOPT_LSRR;
310 break;
311
312 case IPOPT_SSRR:
313 bits |= IP_FW_IPOPT_SSRR;
314 break;
315
316 case IPOPT_RR:
317 bits |= IP_FW_IPOPT_RR;
318 break;
319
320 case IPOPT_TS:
321 bits |= IP_FW_IPOPT_TS;
322 break;
323 }
324 }
325 return (flags_match(cmd, bits));
326 }
327
328 static int
tcpopts_match(struct tcphdr * tcp,ipfw_insn * cmd)329 tcpopts_match(struct tcphdr *tcp, ipfw_insn *cmd)
330 {
331 int optlen, bits = 0;
332 u_char *cp = (u_char *)(tcp + 1);
333 int x = (tcp->th_off << 2) - sizeof(struct tcphdr);
334
335 for (; x > 0; x -= optlen, cp += optlen) {
336 int opt = cp[0];
337 if (opt == TCPOPT_EOL)
338 break;
339 if (opt == TCPOPT_NOP)
340 optlen = 1;
341 else {
342 optlen = cp[1];
343 if (optlen <= 0)
344 break;
345 }
346
347 switch (opt) {
348
349 default:
350 break;
351
352 case TCPOPT_MAXSEG:
353 bits |= IP_FW_TCPOPT_MSS;
354 break;
355
356 case TCPOPT_WINDOW:
357 bits |= IP_FW_TCPOPT_WINDOW;
358 break;
359
360 case TCPOPT_SACK_PERMITTED:
361 case TCPOPT_SACK:
362 bits |= IP_FW_TCPOPT_SACK;
363 break;
364
365 case TCPOPT_TIMESTAMP:
366 bits |= IP_FW_TCPOPT_TS;
367 break;
368
369 }
370 }
371 return (flags_match(cmd, bits));
372 }
373
374 static int
iface_match(struct ifnet * ifp,ipfw_insn_if * cmd,struct ip_fw_chain * chain,uint32_t * tablearg)375 iface_match(struct ifnet *ifp, ipfw_insn_if *cmd, struct ip_fw_chain *chain,
376 uint32_t *tablearg)
377 {
378
379 if (ifp == NULL) /* no iface with this packet, match fails */
380 return (0);
381
382 /* Check by name or by IP address */
383 if (cmd->name[0] != '\0') { /* match by name */
384 if (cmd->name[0] == '\1') /* use tablearg to match */
385 return ipfw_lookup_table_extended(chain, cmd->p.kidx, 0,
386 &ifp->if_index, tablearg);
387 /* Check name */
388 if (cmd->p.glob) {
389 if (fnmatch(cmd->name, ifp->if_xname, 0) == 0)
390 return(1);
391 } else {
392 if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
393 return(1);
394 }
395 } else {
396 #if !defined(USERSPACE) && defined(__FreeBSD__) /* and OSX too ? */
397 struct ifaddr *ia;
398
399 if_addr_rlock(ifp);
400 TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
401 if (ia->ifa_addr->sa_family != AF_INET)
402 continue;
403 if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
404 (ia->ifa_addr))->sin_addr.s_addr) {
405 if_addr_runlock(ifp);
406 return(1); /* match */
407 }
408 }
409 if_addr_runlock(ifp);
410 #endif /* __FreeBSD__ */
411 }
412 return(0); /* no match, fail ... */
413 }
414
415 /*
416 * The verify_path function checks if a route to the src exists and
417 * if it is reachable via ifp (when provided).
418 *
419 * The 'verrevpath' option checks that the interface that an IP packet
420 * arrives on is the same interface that traffic destined for the
421 * packet's source address would be routed out of.
422 * The 'versrcreach' option just checks that the source address is
423 * reachable via any route (except default) in the routing table.
424 * These two are a measure to block forged packets. This is also
425 * commonly known as "anti-spoofing" or Unicast Reverse Path
426 * Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs
427 * is purposely reminiscent of the Cisco IOS command,
428 *
429 * ip verify unicast reverse-path
430 * ip verify unicast source reachable-via any
431 *
432 * which implements the same functionality. But note that the syntax
433 * is misleading, and the check may be performed on all IP packets
434 * whether unicast, multicast, or broadcast.
435 */
436 static int
verify_path(struct in_addr src,struct ifnet * ifp,u_int fib)437 verify_path(struct in_addr src, struct ifnet *ifp, u_int fib)
438 {
439 #if defined(USERSPACE) || !defined(__FreeBSD__)
440 return 0;
441 #else
442 struct nhop4_basic nh4;
443
444 if (fib4_lookup_nh_basic(fib, src, NHR_IFAIF, 0, &nh4) != 0)
445 return (0);
446
447 /*
448 * If ifp is provided, check for equality with rtentry.
449 * We should use rt->rt_ifa->ifa_ifp, instead of rt->rt_ifp,
450 * in order to pass packets injected back by if_simloop():
451 * routing entry (via lo0) for our own address
452 * may exist, so we need to handle routing assymetry.
453 */
454 if (ifp != NULL && ifp != nh4.nh_ifp)
455 return (0);
456
457 /* if no ifp provided, check if rtentry is not default route */
458 if (ifp == NULL && (nh4.nh_flags & NHF_DEFAULT) != 0)
459 return (0);
460
461 /* or if this is a blackhole/reject route */
462 if (ifp == NULL && (nh4.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0)
463 return (0);
464
465 /* found valid route */
466 return 1;
467 #endif /* __FreeBSD__ */
468 }
469
470 #ifdef INET6
471 /*
472 * ipv6 specific rules here...
473 */
474 static __inline int
icmp6type_match(int type,ipfw_insn_u32 * cmd)475 icmp6type_match (int type, ipfw_insn_u32 *cmd)
476 {
477 return (type <= ICMP6_MAXTYPE && (cmd->d[type/32] & (1<<(type%32)) ) );
478 }
479
480 static int
flow6id_match(int curr_flow,ipfw_insn_u32 * cmd)481 flow6id_match( int curr_flow, ipfw_insn_u32 *cmd )
482 {
483 int i;
484 for (i=0; i <= cmd->o.arg1; ++i )
485 if (curr_flow == cmd->d[i] )
486 return 1;
487 return 0;
488 }
489
490 /* support for IP6_*_ME opcodes */
491 static const struct in6_addr lla_mask = {{{
492 0xff, 0xff, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff,
493 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
494 }}};
495
496 static int
ipfw_localip6(struct in6_addr * in6)497 ipfw_localip6(struct in6_addr *in6)
498 {
499 struct rm_priotracker in6_ifa_tracker;
500 struct in6_ifaddr *ia;
501
502 if (IN6_IS_ADDR_MULTICAST(in6))
503 return (0);
504
505 if (!IN6_IS_ADDR_LINKLOCAL(in6))
506 return (in6_localip(in6));
507
508 IN6_IFADDR_RLOCK(&in6_ifa_tracker);
509 TAILQ_FOREACH(ia, &V_in6_ifaddrhead, ia_link) {
510 if (!IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr))
511 continue;
512 if (IN6_ARE_MASKED_ADDR_EQUAL(&ia->ia_addr.sin6_addr,
513 in6, &lla_mask)) {
514 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
515 return (1);
516 }
517 }
518 IN6_IFADDR_RUNLOCK(&in6_ifa_tracker);
519 return (0);
520 }
521
522 static int
verify_path6(struct in6_addr * src,struct ifnet * ifp,u_int fib)523 verify_path6(struct in6_addr *src, struct ifnet *ifp, u_int fib)
524 {
525 struct nhop6_basic nh6;
526
527 if (IN6_IS_SCOPE_LINKLOCAL(src))
528 return (1);
529
530 if (fib6_lookup_nh_basic(fib, src, 0, NHR_IFAIF, 0, &nh6) != 0)
531 return (0);
532
533 /* If ifp is provided, check for equality with route table. */
534 if (ifp != NULL && ifp != nh6.nh_ifp)
535 return (0);
536
537 /* if no ifp provided, check if rtentry is not default route */
538 if (ifp == NULL && (nh6.nh_flags & NHF_DEFAULT) != 0)
539 return (0);
540
541 /* or if this is a blackhole/reject route */
542 if (ifp == NULL && (nh6.nh_flags & (NHF_REJECT|NHF_BLACKHOLE)) != 0)
543 return (0);
544
545 /* found valid route */
546 return 1;
547 }
548
549 static int
is_icmp6_query(int icmp6_type)550 is_icmp6_query(int icmp6_type)
551 {
552 if ((icmp6_type <= ICMP6_MAXTYPE) &&
553 (icmp6_type == ICMP6_ECHO_REQUEST ||
554 icmp6_type == ICMP6_MEMBERSHIP_QUERY ||
555 icmp6_type == ICMP6_WRUREQUEST ||
556 icmp6_type == ICMP6_FQDN_QUERY ||
557 icmp6_type == ICMP6_NI_QUERY))
558 return (1);
559
560 return (0);
561 }
562
563 static void
send_reject6(struct ip_fw_args * args,int code,u_int hlen,struct ip6_hdr * ip6)564 send_reject6(struct ip_fw_args *args, int code, u_int hlen, struct ip6_hdr *ip6)
565 {
566 struct mbuf *m;
567
568 m = args->m;
569 if (code == ICMP6_UNREACH_RST && args->f_id.proto == IPPROTO_TCP) {
570 struct tcphdr *tcp;
571 tcp = (struct tcphdr *)((char *)ip6 + hlen);
572
573 if ((tcp->th_flags & TH_RST) == 0) {
574 struct mbuf *m0;
575 m0 = ipfw_send_pkt(args->m, &(args->f_id),
576 ntohl(tcp->th_seq), ntohl(tcp->th_ack),
577 tcp->th_flags | TH_RST);
578 if (m0 != NULL)
579 ip6_output(m0, NULL, NULL, 0, NULL, NULL,
580 NULL);
581 }
582 FREE_PKT(m);
583 } else if (code != ICMP6_UNREACH_RST) { /* Send an ICMPv6 unreach. */
584 #if 0
585 /*
586 * Unlike above, the mbufs need to line up with the ip6 hdr,
587 * as the contents are read. We need to m_adj() the
588 * needed amount.
589 * The mbuf will however be thrown away so we can adjust it.
590 * Remember we did an m_pullup on it already so we
591 * can make some assumptions about contiguousness.
592 */
593 if (args->L3offset)
594 m_adj(m, args->L3offset);
595 #endif
596 icmp6_error(m, ICMP6_DST_UNREACH, code, 0);
597 } else
598 FREE_PKT(m);
599
600 args->m = NULL;
601 }
602
603 #endif /* INET6 */
604
605
606 /*
607 * sends a reject message, consuming the mbuf passed as an argument.
608 */
609 static void
send_reject(struct ip_fw_args * args,int code,int iplen,struct ip * ip)610 send_reject(struct ip_fw_args *args, int code, int iplen, struct ip *ip)
611 {
612
613 #if 0
614 /* XXX When ip is not guaranteed to be at mtod() we will
615 * need to account for this */
616 * The mbuf will however be thrown away so we can adjust it.
617 * Remember we did an m_pullup on it already so we
618 * can make some assumptions about contiguousness.
619 */
620 if (args->L3offset)
621 m_adj(m, args->L3offset);
622 #endif
623 if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */
624 icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
625 } else if (args->f_id.proto == IPPROTO_TCP) {
626 struct tcphdr *const tcp =
627 L3HDR(struct tcphdr, mtod(args->m, struct ip *));
628 if ( (tcp->th_flags & TH_RST) == 0) {
629 struct mbuf *m;
630 m = ipfw_send_pkt(args->m, &(args->f_id),
631 ntohl(tcp->th_seq), ntohl(tcp->th_ack),
632 tcp->th_flags | TH_RST);
633 if (m != NULL)
634 ip_output(m, NULL, NULL, 0, NULL, NULL);
635 }
636 FREE_PKT(args->m);
637 } else
638 FREE_PKT(args->m);
639 args->m = NULL;
640 }
641
642 /*
643 * Support for uid/gid/jail lookup. These tests are expensive
644 * (because we may need to look into the list of active sockets)
645 * so we cache the results. ugid_lookupp is 0 if we have not
646 * yet done a lookup, 1 if we succeeded, and -1 if we tried
647 * and failed. The function always returns the match value.
648 * We could actually spare the variable and use *uc, setting
649 * it to '(void *)check_uidgid if we have no info, NULL if
650 * we tried and failed, or any other value if successful.
651 */
652 static int
check_uidgid(ipfw_insn_u32 * insn,struct ip_fw_args * args,int * ugid_lookupp,struct ucred ** uc)653 check_uidgid(ipfw_insn_u32 *insn, struct ip_fw_args *args, int *ugid_lookupp,
654 struct ucred **uc)
655 {
656 #if defined(USERSPACE)
657 return 0; // not supported in userspace
658 #else
659 #ifndef __FreeBSD__
660 /* XXX */
661 return cred_check(insn, proto, oif,
662 dst_ip, dst_port, src_ip, src_port,
663 (struct bsd_ucred *)uc, ugid_lookupp, ((struct mbuf *)inp)->m_skb);
664 #else /* FreeBSD */
665 struct in_addr src_ip, dst_ip;
666 struct inpcbinfo *pi;
667 struct ipfw_flow_id *id;
668 struct inpcb *pcb, *inp;
669 struct ifnet *oif;
670 int lookupflags;
671 int match;
672
673 id = &args->f_id;
674 inp = args->inp;
675 oif = args->oif;
676
677 /*
678 * Check to see if the UDP or TCP stack supplied us with
679 * the PCB. If so, rather then holding a lock and looking
680 * up the PCB, we can use the one that was supplied.
681 */
682 if (inp && *ugid_lookupp == 0) {
683 INP_LOCK_ASSERT(inp);
684 if (inp->inp_socket != NULL) {
685 *uc = crhold(inp->inp_cred);
686 *ugid_lookupp = 1;
687 } else
688 *ugid_lookupp = -1;
689 }
690 /*
691 * If we have already been here and the packet has no
692 * PCB entry associated with it, then we can safely
693 * assume that this is a no match.
694 */
695 if (*ugid_lookupp == -1)
696 return (0);
697 if (id->proto == IPPROTO_TCP) {
698 lookupflags = 0;
699 pi = &V_tcbinfo;
700 } else if (id->proto == IPPROTO_UDP) {
701 lookupflags = INPLOOKUP_WILDCARD;
702 pi = &V_udbinfo;
703 } else
704 return 0;
705 lookupflags |= INPLOOKUP_RLOCKPCB;
706 match = 0;
707 if (*ugid_lookupp == 0) {
708 if (id->addr_type == 6) {
709 #ifdef INET6
710 if (oif == NULL)
711 pcb = in6_pcblookup_mbuf(pi,
712 &id->src_ip6, htons(id->src_port),
713 &id->dst_ip6, htons(id->dst_port),
714 lookupflags, oif, args->m);
715 else
716 pcb = in6_pcblookup_mbuf(pi,
717 &id->dst_ip6, htons(id->dst_port),
718 &id->src_ip6, htons(id->src_port),
719 lookupflags, oif, args->m);
720 #else
721 *ugid_lookupp = -1;
722 return (0);
723 #endif
724 } else {
725 src_ip.s_addr = htonl(id->src_ip);
726 dst_ip.s_addr = htonl(id->dst_ip);
727 if (oif == NULL)
728 pcb = in_pcblookup_mbuf(pi,
729 src_ip, htons(id->src_port),
730 dst_ip, htons(id->dst_port),
731 lookupflags, oif, args->m);
732 else
733 pcb = in_pcblookup_mbuf(pi,
734 dst_ip, htons(id->dst_port),
735 src_ip, htons(id->src_port),
736 lookupflags, oif, args->m);
737 }
738 if (pcb != NULL) {
739 INP_RLOCK_ASSERT(pcb);
740 *uc = crhold(pcb->inp_cred);
741 *ugid_lookupp = 1;
742 INP_RUNLOCK(pcb);
743 }
744 if (*ugid_lookupp == 0) {
745 /*
746 * We tried and failed, set the variable to -1
747 * so we will not try again on this packet.
748 */
749 *ugid_lookupp = -1;
750 return (0);
751 }
752 }
753 if (insn->o.opcode == O_UID)
754 match = ((*uc)->cr_uid == (uid_t)insn->d[0]);
755 else if (insn->o.opcode == O_GID)
756 match = groupmember((gid_t)insn->d[0], *uc);
757 else if (insn->o.opcode == O_JAIL)
758 match = ((*uc)->cr_prison->pr_id == (int)insn->d[0]);
759 return (match);
760 #endif /* __FreeBSD__ */
761 #endif /* not supported in userspace */
762 }
763
764 /*
765 * Helper function to set args with info on the rule after the matching
766 * one. slot is precise, whereas we guess rule_id as they are
767 * assigned sequentially.
768 */
769 static inline void
set_match(struct ip_fw_args * args,int slot,struct ip_fw_chain * chain)770 set_match(struct ip_fw_args *args, int slot,
771 struct ip_fw_chain *chain)
772 {
773 args->rule.chain_id = chain->id;
774 args->rule.slot = slot + 1; /* we use 0 as a marker */
775 args->rule.rule_id = 1 + chain->map[slot]->id;
776 args->rule.rulenum = chain->map[slot]->rulenum;
777 }
778
779 #ifndef LINEAR_SKIPTO
780 /*
781 * Helper function to enable cached rule lookups using
782 * cached_id and cached_pos fields in ipfw rule.
783 */
784 static int
jump_fast(struct ip_fw_chain * chain,struct ip_fw * f,int num,int tablearg,int jump_backwards)785 jump_fast(struct ip_fw_chain *chain, struct ip_fw *f, int num,
786 int tablearg, int jump_backwards)
787 {
788 int f_pos;
789
790 /* If possible use cached f_pos (in f->cached_pos),
791 * whose version is written in f->cached_id
792 * (horrible hacks to avoid changing the ABI).
793 */
794 if (num != IP_FW_TARG && f->cached_id == chain->id)
795 f_pos = f->cached_pos;
796 else {
797 int i = IP_FW_ARG_TABLEARG(chain, num, skipto);
798 /* make sure we do not jump backward */
799 if (jump_backwards == 0 && i <= f->rulenum)
800 i = f->rulenum + 1;
801 if (chain->idxmap != NULL)
802 f_pos = chain->idxmap[i];
803 else
804 f_pos = ipfw_find_rule(chain, i, 0);
805 /* update the cache */
806 if (num != IP_FW_TARG) {
807 f->cached_id = chain->id;
808 f->cached_pos = f_pos;
809 }
810 }
811
812 return (f_pos);
813 }
814 #else
815 /*
816 * Helper function to enable real fast rule lookups.
817 */
818 static int
jump_linear(struct ip_fw_chain * chain,struct ip_fw * f,int num,int tablearg,int jump_backwards)819 jump_linear(struct ip_fw_chain *chain, struct ip_fw *f, int num,
820 int tablearg, int jump_backwards)
821 {
822 int f_pos;
823
824 num = IP_FW_ARG_TABLEARG(chain, num, skipto);
825 /* make sure we do not jump backward */
826 if (jump_backwards == 0 && num <= f->rulenum)
827 num = f->rulenum + 1;
828 f_pos = chain->idxmap[num];
829
830 return (f_pos);
831 }
832 #endif
833
834 #define TARG(k, f) IP_FW_ARG_TABLEARG(chain, k, f)
835 /*
836 * The main check routine for the firewall.
837 *
838 * All arguments are in args so we can modify them and return them
839 * back to the caller.
840 *
841 * Parameters:
842 *
843 * args->m (in/out) The packet; we set to NULL when/if we nuke it.
844 * Starts with the IP header.
845 * args->eh (in) Mac header if present, NULL for layer3 packet.
846 * args->L3offset Number of bytes bypassed if we came from L2.
847 * e.g. often sizeof(eh) ** NOTYET **
848 * args->oif Outgoing interface, NULL if packet is incoming.
849 * The incoming interface is in the mbuf. (in)
850 * args->divert_rule (in/out)
851 * Skip up to the first rule past this rule number;
852 * upon return, non-zero port number for divert or tee.
853 *
854 * args->rule Pointer to the last matching rule (in/out)
855 * args->next_hop Socket we are forwarding to (out).
856 * args->next_hop6 IPv6 next hop we are forwarding to (out).
857 * args->f_id Addresses grabbed from the packet (out)
858 * args->rule.info a cookie depending on rule action
859 *
860 * Return value:
861 *
862 * IP_FW_PASS the packet must be accepted
863 * IP_FW_DENY the packet must be dropped
864 * IP_FW_DIVERT divert packet, port in m_tag
865 * IP_FW_TEE tee packet, port in m_tag
866 * IP_FW_DUMMYNET to dummynet, pipe in args->cookie
867 * IP_FW_NETGRAPH into netgraph, cookie args->cookie
868 * args->rule contains the matching rule,
869 * args->rule.info has additional information.
870 *
871 */
872 int
ipfw_chk(struct ip_fw_args * args)873 ipfw_chk(struct ip_fw_args *args)
874 {
875
876 /*
877 * Local variables holding state while processing a packet:
878 *
879 * IMPORTANT NOTE: to speed up the processing of rules, there
880 * are some assumption on the values of the variables, which
881 * are documented here. Should you change them, please check
882 * the implementation of the various instructions to make sure
883 * that they still work.
884 *
885 * args->eh The MAC header. It is non-null for a layer2
886 * packet, it is NULL for a layer-3 packet.
887 * **notyet**
888 * args->L3offset Offset in the packet to the L3 (IP or equiv.) header.
889 *
890 * m | args->m Pointer to the mbuf, as received from the caller.
891 * It may change if ipfw_chk() does an m_pullup, or if it
892 * consumes the packet because it calls send_reject().
893 * XXX This has to change, so that ipfw_chk() never modifies
894 * or consumes the buffer.
895 * ip is the beginning of the ip(4 or 6) header.
896 * Calculated by adding the L3offset to the start of data.
897 * (Until we start using L3offset, the packet is
898 * supposed to start with the ip header).
899 */
900 struct mbuf *m = args->m;
901 struct ip *ip = mtod(m, struct ip *);
902
903 /*
904 * For rules which contain uid/gid or jail constraints, cache
905 * a copy of the users credentials after the pcb lookup has been
906 * executed. This will speed up the processing of rules with
907 * these types of constraints, as well as decrease contention
908 * on pcb related locks.
909 */
910 #ifndef __FreeBSD__
911 struct bsd_ucred ucred_cache;
912 #else
913 struct ucred *ucred_cache = NULL;
914 #endif
915 int ucred_lookup = 0;
916
917 /*
918 * oif | args->oif If NULL, ipfw_chk has been called on the
919 * inbound path (ether_input, ip_input).
920 * If non-NULL, ipfw_chk has been called on the outbound path
921 * (ether_output, ip_output).
922 */
923 struct ifnet *oif = args->oif;
924
925 int f_pos = 0; /* index of current rule in the array */
926 int retval = 0;
927
928 /*
929 * hlen The length of the IP header.
930 */
931 u_int hlen = 0; /* hlen >0 means we have an IP pkt */
932
933 /*
934 * offset The offset of a fragment. offset != 0 means that
935 * we have a fragment at this offset of an IPv4 packet.
936 * offset == 0 means that (if this is an IPv4 packet)
937 * this is the first or only fragment.
938 * For IPv6 offset|ip6f_mf == 0 means there is no Fragment Header
939 * or there is a single packet fragement (fragement header added
940 * without needed). We will treat a single packet fragment as if
941 * there was no fragment header (or log/block depending on the
942 * V_fw_permit_single_frag6 sysctl setting).
943 */
944 u_short offset = 0;
945 u_short ip6f_mf = 0;
946
947 /*
948 * Local copies of addresses. They are only valid if we have
949 * an IP packet.
950 *
951 * proto The protocol. Set to 0 for non-ip packets,
952 * or to the protocol read from the packet otherwise.
953 * proto != 0 means that we have an IPv4 packet.
954 *
955 * src_port, dst_port port numbers, in HOST format. Only
956 * valid for TCP and UDP packets.
957 *
958 * src_ip, dst_ip ip addresses, in NETWORK format.
959 * Only valid for IPv4 packets.
960 */
961 uint8_t proto;
962 uint16_t src_port = 0, dst_port = 0; /* NOTE: host format */
963 struct in_addr src_ip, dst_ip; /* NOTE: network format */
964 uint16_t iplen=0;
965 int pktlen;
966 uint16_t etype = 0; /* Host order stored ether type */
967
968 /*
969 * dyn_dir = MATCH_UNKNOWN when rules unchecked,
970 * MATCH_NONE when checked and not matched (q = NULL),
971 * MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL)
972 */
973 int dyn_dir = MATCH_UNKNOWN;
974 ipfw_dyn_rule *q = NULL;
975 struct ip_fw_chain *chain = &V_layer3_chain;
976
977 /*
978 * We store in ulp a pointer to the upper layer protocol header.
979 * In the ipv4 case this is easy to determine from the header,
980 * but for ipv6 we might have some additional headers in the middle.
981 * ulp is NULL if not found.
982 */
983 void *ulp = NULL; /* upper layer protocol pointer. */
984
985 /* XXX ipv6 variables */
986 int is_ipv6 = 0;
987 uint8_t icmp6_type = 0;
988 uint16_t ext_hd = 0; /* bits vector for extension header filtering */
989 /* end of ipv6 variables */
990
991 int is_ipv4 = 0;
992
993 int done = 0; /* flag to exit the outer loop */
994 IPFW_RLOCK_TRACKER;
995
996 if (m->m_flags & M_SKIP_FIREWALL || (! V_ipfw_vnet_ready))
997 return (IP_FW_PASS); /* accept */
998
999 dst_ip.s_addr = 0; /* make sure it is initialized */
1000 src_ip.s_addr = 0; /* make sure it is initialized */
1001 pktlen = m->m_pkthdr.len;
1002 args->f_id.fib = M_GETFIB(m); /* note mbuf not altered) */
1003 proto = args->f_id.proto = 0; /* mark f_id invalid */
1004 /* XXX 0 is a valid proto: IP/IPv6 Hop-by-Hop Option */
1005
1006 /*
1007 * PULLUP_TO(len, p, T) makes sure that len + sizeof(T) is contiguous,
1008 * then it sets p to point at the offset "len" in the mbuf. WARNING: the
1009 * pointer might become stale after other pullups (but we never use it
1010 * this way).
1011 */
1012 #define PULLUP_TO(_len, p, T) PULLUP_LEN(_len, p, sizeof(T))
1013 #define PULLUP_LEN(_len, p, T) \
1014 do { \
1015 int x = (_len) + T; \
1016 if ((m)->m_len < x) { \
1017 args->m = m = m_pullup(m, x); \
1018 if (m == NULL) \
1019 goto pullup_failed; \
1020 } \
1021 p = (mtod(m, char *) + (_len)); \
1022 } while (0)
1023
1024 /*
1025 * if we have an ether header,
1026 */
1027 if (args->eh)
1028 etype = ntohs(args->eh->ether_type);
1029
1030 /* Identify IP packets and fill up variables. */
1031 if (pktlen >= sizeof(struct ip6_hdr) &&
1032 (args->eh == NULL || etype == ETHERTYPE_IPV6) && ip->ip_v == 6) {
1033 struct ip6_hdr *ip6 = (struct ip6_hdr *)ip;
1034 is_ipv6 = 1;
1035 args->f_id.addr_type = 6;
1036 hlen = sizeof(struct ip6_hdr);
1037 proto = ip6->ip6_nxt;
1038
1039 /* Search extension headers to find upper layer protocols */
1040 while (ulp == NULL && offset == 0) {
1041 switch (proto) {
1042 case IPPROTO_ICMPV6:
1043 PULLUP_TO(hlen, ulp, struct icmp6_hdr);
1044 icmp6_type = ICMP6(ulp)->icmp6_type;
1045 break;
1046
1047 case IPPROTO_TCP:
1048 PULLUP_TO(hlen, ulp, struct tcphdr);
1049 dst_port = TCP(ulp)->th_dport;
1050 src_port = TCP(ulp)->th_sport;
1051 /* save flags for dynamic rules */
1052 args->f_id._flags = TCP(ulp)->th_flags;
1053 break;
1054
1055 case IPPROTO_SCTP:
1056 PULLUP_TO(hlen, ulp, struct sctphdr);
1057 src_port = SCTP(ulp)->src_port;
1058 dst_port = SCTP(ulp)->dest_port;
1059 break;
1060
1061 case IPPROTO_UDP:
1062 PULLUP_TO(hlen, ulp, struct udphdr);
1063 dst_port = UDP(ulp)->uh_dport;
1064 src_port = UDP(ulp)->uh_sport;
1065 break;
1066
1067 case IPPROTO_HOPOPTS: /* RFC 2460 */
1068 PULLUP_TO(hlen, ulp, struct ip6_hbh);
1069 ext_hd |= EXT_HOPOPTS;
1070 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
1071 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
1072 ulp = NULL;
1073 break;
1074
1075 case IPPROTO_ROUTING: /* RFC 2460 */
1076 PULLUP_TO(hlen, ulp, struct ip6_rthdr);
1077 switch (((struct ip6_rthdr *)ulp)->ip6r_type) {
1078 case 0:
1079 ext_hd |= EXT_RTHDR0;
1080 break;
1081 case 2:
1082 ext_hd |= EXT_RTHDR2;
1083 break;
1084 default:
1085 if (V_fw_verbose)
1086 printf("IPFW2: IPV6 - Unknown "
1087 "Routing Header type(%d)\n",
1088 ((struct ip6_rthdr *)
1089 ulp)->ip6r_type);
1090 if (V_fw_deny_unknown_exthdrs)
1091 return (IP_FW_DENY);
1092 break;
1093 }
1094 ext_hd |= EXT_ROUTING;
1095 hlen += (((struct ip6_rthdr *)ulp)->ip6r_len + 1) << 3;
1096 proto = ((struct ip6_rthdr *)ulp)->ip6r_nxt;
1097 ulp = NULL;
1098 break;
1099
1100 case IPPROTO_FRAGMENT: /* RFC 2460 */
1101 PULLUP_TO(hlen, ulp, struct ip6_frag);
1102 ext_hd |= EXT_FRAGMENT;
1103 hlen += sizeof (struct ip6_frag);
1104 proto = ((struct ip6_frag *)ulp)->ip6f_nxt;
1105 offset = ((struct ip6_frag *)ulp)->ip6f_offlg &
1106 IP6F_OFF_MASK;
1107 ip6f_mf = ((struct ip6_frag *)ulp)->ip6f_offlg &
1108 IP6F_MORE_FRAG;
1109 if (V_fw_permit_single_frag6 == 0 &&
1110 offset == 0 && ip6f_mf == 0) {
1111 if (V_fw_verbose)
1112 printf("IPFW2: IPV6 - Invalid "
1113 "Fragment Header\n");
1114 if (V_fw_deny_unknown_exthdrs)
1115 return (IP_FW_DENY);
1116 break;
1117 }
1118 args->f_id.extra =
1119 ntohl(((struct ip6_frag *)ulp)->ip6f_ident);
1120 ulp = NULL;
1121 break;
1122
1123 case IPPROTO_DSTOPTS: /* RFC 2460 */
1124 PULLUP_TO(hlen, ulp, struct ip6_hbh);
1125 ext_hd |= EXT_DSTOPTS;
1126 hlen += (((struct ip6_hbh *)ulp)->ip6h_len + 1) << 3;
1127 proto = ((struct ip6_hbh *)ulp)->ip6h_nxt;
1128 ulp = NULL;
1129 break;
1130
1131 case IPPROTO_AH: /* RFC 2402 */
1132 PULLUP_TO(hlen, ulp, struct ip6_ext);
1133 ext_hd |= EXT_AH;
1134 hlen += (((struct ip6_ext *)ulp)->ip6e_len + 2) << 2;
1135 proto = ((struct ip6_ext *)ulp)->ip6e_nxt;
1136 ulp = NULL;
1137 break;
1138
1139 case IPPROTO_ESP: /* RFC 2406 */
1140 PULLUP_TO(hlen, ulp, uint32_t); /* SPI, Seq# */
1141 /* Anything past Seq# is variable length and
1142 * data past this ext. header is encrypted. */
1143 ext_hd |= EXT_ESP;
1144 break;
1145
1146 case IPPROTO_NONE: /* RFC 2460 */
1147 /*
1148 * Packet ends here, and IPv6 header has
1149 * already been pulled up. If ip6e_len!=0
1150 * then octets must be ignored.
1151 */
1152 ulp = ip; /* non-NULL to get out of loop. */
1153 break;
1154
1155 case IPPROTO_OSPFIGP:
1156 /* XXX OSPF header check? */
1157 PULLUP_TO(hlen, ulp, struct ip6_ext);
1158 break;
1159
1160 case IPPROTO_PIM:
1161 /* XXX PIM header check? */
1162 PULLUP_TO(hlen, ulp, struct pim);
1163 break;
1164
1165 case IPPROTO_CARP:
1166 PULLUP_TO(hlen, ulp, struct carp_header);
1167 if (((struct carp_header *)ulp)->carp_version !=
1168 CARP_VERSION)
1169 return (IP_FW_DENY);
1170 if (((struct carp_header *)ulp)->carp_type !=
1171 CARP_ADVERTISEMENT)
1172 return (IP_FW_DENY);
1173 break;
1174
1175 case IPPROTO_IPV6: /* RFC 2893 */
1176 PULLUP_TO(hlen, ulp, struct ip6_hdr);
1177 break;
1178
1179 case IPPROTO_IPV4: /* RFC 2893 */
1180 PULLUP_TO(hlen, ulp, struct ip);
1181 break;
1182
1183 default:
1184 if (V_fw_verbose)
1185 printf("IPFW2: IPV6 - Unknown "
1186 "Extension Header(%d), ext_hd=%x\n",
1187 proto, ext_hd);
1188 if (V_fw_deny_unknown_exthdrs)
1189 return (IP_FW_DENY);
1190 PULLUP_TO(hlen, ulp, struct ip6_ext);
1191 break;
1192 } /*switch */
1193 }
1194 ip = mtod(m, struct ip *);
1195 ip6 = (struct ip6_hdr *)ip;
1196 args->f_id.src_ip6 = ip6->ip6_src;
1197 args->f_id.dst_ip6 = ip6->ip6_dst;
1198 args->f_id.src_ip = 0;
1199 args->f_id.dst_ip = 0;
1200 args->f_id.flow_id6 = ntohl(ip6->ip6_flow);
1201 } else if (pktlen >= sizeof(struct ip) &&
1202 (args->eh == NULL || etype == ETHERTYPE_IP) && ip->ip_v == 4) {
1203 is_ipv4 = 1;
1204 hlen = ip->ip_hl << 2;
1205 args->f_id.addr_type = 4;
1206
1207 /*
1208 * Collect parameters into local variables for faster matching.
1209 */
1210 proto = ip->ip_p;
1211 src_ip = ip->ip_src;
1212 dst_ip = ip->ip_dst;
1213 offset = ntohs(ip->ip_off) & IP_OFFMASK;
1214 iplen = ntohs(ip->ip_len);
1215 pktlen = iplen < pktlen ? iplen : pktlen;
1216
1217 if (offset == 0) {
1218 switch (proto) {
1219 case IPPROTO_TCP:
1220 PULLUP_TO(hlen, ulp, struct tcphdr);
1221 dst_port = TCP(ulp)->th_dport;
1222 src_port = TCP(ulp)->th_sport;
1223 /* save flags for dynamic rules */
1224 args->f_id._flags = TCP(ulp)->th_flags;
1225 break;
1226
1227 case IPPROTO_SCTP:
1228 PULLUP_TO(hlen, ulp, struct sctphdr);
1229 src_port = SCTP(ulp)->src_port;
1230 dst_port = SCTP(ulp)->dest_port;
1231 break;
1232
1233 case IPPROTO_UDP:
1234 PULLUP_TO(hlen, ulp, struct udphdr);
1235 dst_port = UDP(ulp)->uh_dport;
1236 src_port = UDP(ulp)->uh_sport;
1237 break;
1238
1239 case IPPROTO_ICMP:
1240 PULLUP_TO(hlen, ulp, struct icmphdr);
1241 //args->f_id.flags = ICMP(ulp)->icmp_type;
1242 break;
1243
1244 default:
1245 break;
1246 }
1247 }
1248
1249 ip = mtod(m, struct ip *);
1250 args->f_id.src_ip = ntohl(src_ip.s_addr);
1251 args->f_id.dst_ip = ntohl(dst_ip.s_addr);
1252 }
1253 #undef PULLUP_TO
1254 if (proto) { /* we may have port numbers, store them */
1255 args->f_id.proto = proto;
1256 args->f_id.src_port = src_port = ntohs(src_port);
1257 args->f_id.dst_port = dst_port = ntohs(dst_port);
1258 }
1259
1260 IPFW_PF_RLOCK(chain);
1261 if (! V_ipfw_vnet_ready) { /* shutting down, leave NOW. */
1262 IPFW_PF_RUNLOCK(chain);
1263 return (IP_FW_PASS); /* accept */
1264 }
1265 if (args->rule.slot) {
1266 /*
1267 * Packet has already been tagged as a result of a previous
1268 * match on rule args->rule aka args->rule_id (PIPE, QUEUE,
1269 * REASS, NETGRAPH, DIVERT/TEE...)
1270 * Validate the slot and continue from the next one
1271 * if still present, otherwise do a lookup.
1272 */
1273 f_pos = (args->rule.chain_id == chain->id) ?
1274 args->rule.slot :
1275 ipfw_find_rule(chain, args->rule.rulenum,
1276 args->rule.rule_id);
1277 } else {
1278 f_pos = 0;
1279 }
1280
1281 /*
1282 * Now scan the rules, and parse microinstructions for each rule.
1283 * We have two nested loops and an inner switch. Sometimes we
1284 * need to break out of one or both loops, or re-enter one of
1285 * the loops with updated variables. Loop variables are:
1286 *
1287 * f_pos (outer loop) points to the current rule.
1288 * On output it points to the matching rule.
1289 * done (outer loop) is used as a flag to break the loop.
1290 * l (inner loop) residual length of current rule.
1291 * cmd points to the current microinstruction.
1292 *
1293 * We break the inner loop by setting l=0 and possibly
1294 * cmdlen=0 if we don't want to advance cmd.
1295 * We break the outer loop by setting done=1
1296 * We can restart the inner loop by setting l>0 and f_pos, f, cmd
1297 * as needed.
1298 */
1299 for (; f_pos < chain->n_rules; f_pos++) {
1300 ipfw_insn *cmd;
1301 uint32_t tablearg = 0;
1302 int l, cmdlen, skip_or; /* skip rest of OR block */
1303 struct ip_fw *f;
1304
1305 f = chain->map[f_pos];
1306 if (V_set_disable & (1 << f->set) )
1307 continue;
1308
1309 skip_or = 0;
1310 for (l = f->cmd_len, cmd = f->cmd ; l > 0 ;
1311 l -= cmdlen, cmd += cmdlen) {
1312 int match;
1313
1314 /*
1315 * check_body is a jump target used when we find a
1316 * CHECK_STATE, and need to jump to the body of
1317 * the target rule.
1318 */
1319
1320 /* check_body: */
1321 cmdlen = F_LEN(cmd);
1322 /*
1323 * An OR block (insn_1 || .. || insn_n) has the
1324 * F_OR bit set in all but the last instruction.
1325 * The first match will set "skip_or", and cause
1326 * the following instructions to be skipped until
1327 * past the one with the F_OR bit clear.
1328 */
1329 if (skip_or) { /* skip this instruction */
1330 if ((cmd->len & F_OR) == 0)
1331 skip_or = 0; /* next one is good */
1332 continue;
1333 }
1334 match = 0; /* set to 1 if we succeed */
1335
1336 switch (cmd->opcode) {
1337 /*
1338 * The first set of opcodes compares the packet's
1339 * fields with some pattern, setting 'match' if a
1340 * match is found. At the end of the loop there is
1341 * logic to deal with F_NOT and F_OR flags associated
1342 * with the opcode.
1343 */
1344 case O_NOP:
1345 match = 1;
1346 break;
1347
1348 case O_FORWARD_MAC:
1349 printf("ipfw: opcode %d unimplemented\n",
1350 cmd->opcode);
1351 break;
1352
1353 case O_GID:
1354 case O_UID:
1355 case O_JAIL:
1356 /*
1357 * We only check offset == 0 && proto != 0,
1358 * as this ensures that we have a
1359 * packet with the ports info.
1360 */
1361 if (offset != 0)
1362 break;
1363 if (proto == IPPROTO_TCP ||
1364 proto == IPPROTO_UDP)
1365 match = check_uidgid(
1366 (ipfw_insn_u32 *)cmd,
1367 args, &ucred_lookup,
1368 #ifdef __FreeBSD__
1369 &ucred_cache);
1370 #else
1371 (void *)&ucred_cache);
1372 #endif
1373 break;
1374
1375 case O_RECV:
1376 match = iface_match(m->m_pkthdr.rcvif,
1377 (ipfw_insn_if *)cmd, chain, &tablearg);
1378 break;
1379
1380 case O_XMIT:
1381 match = iface_match(oif, (ipfw_insn_if *)cmd,
1382 chain, &tablearg);
1383 break;
1384
1385 case O_VIA:
1386 match = iface_match(oif ? oif :
1387 m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd,
1388 chain, &tablearg);
1389 break;
1390
1391 case O_MACADDR2:
1392 if (args->eh != NULL) { /* have MAC header */
1393 u_int32_t *want = (u_int32_t *)
1394 ((ipfw_insn_mac *)cmd)->addr;
1395 u_int32_t *mask = (u_int32_t *)
1396 ((ipfw_insn_mac *)cmd)->mask;
1397 u_int32_t *hdr = (u_int32_t *)args->eh;
1398
1399 match =
1400 ( want[0] == (hdr[0] & mask[0]) &&
1401 want[1] == (hdr[1] & mask[1]) &&
1402 want[2] == (hdr[2] & mask[2]) );
1403 }
1404 break;
1405
1406 case O_MAC_TYPE:
1407 if (args->eh != NULL) {
1408 u_int16_t *p =
1409 ((ipfw_insn_u16 *)cmd)->ports;
1410 int i;
1411
1412 for (i = cmdlen - 1; !match && i>0;
1413 i--, p += 2)
1414 match = (etype >= p[0] &&
1415 etype <= p[1]);
1416 }
1417 break;
1418
1419 case O_FRAG:
1420 match = (offset != 0);
1421 break;
1422
1423 case O_IN: /* "out" is "not in" */
1424 match = (oif == NULL);
1425 break;
1426
1427 case O_LAYER2:
1428 match = (args->eh != NULL);
1429 break;
1430
1431 case O_DIVERTED:
1432 {
1433 /* For diverted packets, args->rule.info
1434 * contains the divert port (in host format)
1435 * reason and direction.
1436 */
1437 uint32_t i = args->rule.info;
1438 match = (i&IPFW_IS_MASK) == IPFW_IS_DIVERT &&
1439 cmd->arg1 & ((i & IPFW_INFO_IN) ? 1 : 2);
1440 }
1441 break;
1442
1443 case O_PROTO:
1444 /*
1445 * We do not allow an arg of 0 so the
1446 * check of "proto" only suffices.
1447 */
1448 match = (proto == cmd->arg1);
1449 break;
1450
1451 case O_IP_SRC:
1452 match = is_ipv4 &&
1453 (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1454 src_ip.s_addr);
1455 break;
1456
1457 case O_IP_SRC_LOOKUP:
1458 case O_IP_DST_LOOKUP:
1459 if (is_ipv4) {
1460 uint32_t key =
1461 (cmd->opcode == O_IP_DST_LOOKUP) ?
1462 dst_ip.s_addr : src_ip.s_addr;
1463 uint32_t v = 0;
1464
1465 if (cmdlen > F_INSN_SIZE(ipfw_insn_u32)) {
1466 /* generic lookup. The key must be
1467 * in 32bit big-endian format.
1468 */
1469 v = ((ipfw_insn_u32 *)cmd)->d[1];
1470 if (v == 0)
1471 key = dst_ip.s_addr;
1472 else if (v == 1)
1473 key = src_ip.s_addr;
1474 else if (v == 6) /* dscp */
1475 key = (ip->ip_tos >> 2) & 0x3f;
1476 else if (offset != 0)
1477 break;
1478 else if (proto != IPPROTO_TCP &&
1479 proto != IPPROTO_UDP)
1480 break;
1481 else if (v == 2)
1482 key = dst_port;
1483 else if (v == 3)
1484 key = src_port;
1485 #ifndef USERSPACE
1486 else if (v == 4 || v == 5) {
1487 check_uidgid(
1488 (ipfw_insn_u32 *)cmd,
1489 args, &ucred_lookup,
1490 #ifdef __FreeBSD__
1491 &ucred_cache);
1492 if (v == 4 /* O_UID */)
1493 key = ucred_cache->cr_uid;
1494 else if (v == 5 /* O_JAIL */)
1495 key = ucred_cache->cr_prison->pr_id;
1496 #else /* !__FreeBSD__ */
1497 (void *)&ucred_cache);
1498 if (v ==4 /* O_UID */)
1499 key = ucred_cache.uid;
1500 else if (v == 5 /* O_JAIL */)
1501 key = ucred_cache.xid;
1502 #endif /* !__FreeBSD__ */
1503 }
1504 #endif /* !USERSPACE */
1505 else
1506 break;
1507 }
1508 match = ipfw_lookup_table(chain,
1509 cmd->arg1, key, &v);
1510 if (!match)
1511 break;
1512 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
1513 match =
1514 ((ipfw_insn_u32 *)cmd)->d[0] == v;
1515 else
1516 tablearg = v;
1517 } else if (is_ipv6) {
1518 uint32_t v = 0;
1519 void *pkey = (cmd->opcode == O_IP_DST_LOOKUP) ?
1520 &args->f_id.dst_ip6: &args->f_id.src_ip6;
1521 match = ipfw_lookup_table_extended(chain,
1522 cmd->arg1,
1523 sizeof(struct in6_addr),
1524 pkey, &v);
1525 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
1526 match = ((ipfw_insn_u32 *)cmd)->d[0] == v;
1527 if (match)
1528 tablearg = v;
1529 }
1530 break;
1531
1532 case O_IP_FLOW_LOOKUP:
1533 {
1534 uint32_t v = 0;
1535 match = ipfw_lookup_table_extended(chain,
1536 cmd->arg1, 0, &args->f_id, &v);
1537 if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
1538 match = ((ipfw_insn_u32 *)cmd)->d[0] == v;
1539 if (match)
1540 tablearg = v;
1541 }
1542 break;
1543 case O_IP_SRC_MASK:
1544 case O_IP_DST_MASK:
1545 if (is_ipv4) {
1546 uint32_t a =
1547 (cmd->opcode == O_IP_DST_MASK) ?
1548 dst_ip.s_addr : src_ip.s_addr;
1549 uint32_t *p = ((ipfw_insn_u32 *)cmd)->d;
1550 int i = cmdlen-1;
1551
1552 for (; !match && i>0; i-= 2, p+= 2)
1553 match = (p[0] == (a & p[1]));
1554 }
1555 break;
1556
1557 case O_IP_SRC_ME:
1558 if (is_ipv4) {
1559 struct ifnet *tif;
1560
1561 INADDR_TO_IFP(src_ip, tif);
1562 match = (tif != NULL);
1563 break;
1564 }
1565 #ifdef INET6
1566 /* FALLTHROUGH */
1567 case O_IP6_SRC_ME:
1568 match= is_ipv6 && ipfw_localip6(&args->f_id.src_ip6);
1569 #endif
1570 break;
1571
1572 case O_IP_DST_SET:
1573 case O_IP_SRC_SET:
1574 if (is_ipv4) {
1575 u_int32_t *d = (u_int32_t *)(cmd+1);
1576 u_int32_t addr =
1577 cmd->opcode == O_IP_DST_SET ?
1578 args->f_id.dst_ip :
1579 args->f_id.src_ip;
1580
1581 if (addr < d[0])
1582 break;
1583 addr -= d[0]; /* subtract base */
1584 match = (addr < cmd->arg1) &&
1585 ( d[ 1 + (addr>>5)] &
1586 (1<<(addr & 0x1f)) );
1587 }
1588 break;
1589
1590 case O_IP_DST:
1591 match = is_ipv4 &&
1592 (((ipfw_insn_ip *)cmd)->addr.s_addr ==
1593 dst_ip.s_addr);
1594 break;
1595
1596 case O_IP_DST_ME:
1597 if (is_ipv4) {
1598 struct ifnet *tif;
1599
1600 INADDR_TO_IFP(dst_ip, tif);
1601 match = (tif != NULL);
1602 break;
1603 }
1604 #ifdef INET6
1605 /* FALLTHROUGH */
1606 case O_IP6_DST_ME:
1607 match= is_ipv6 && ipfw_localip6(&args->f_id.dst_ip6);
1608 #endif
1609 break;
1610
1611
1612 case O_IP_SRCPORT:
1613 case O_IP_DSTPORT:
1614 /*
1615 * offset == 0 && proto != 0 is enough
1616 * to guarantee that we have a
1617 * packet with port info.
1618 */
1619 if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP)
1620 && offset == 0) {
1621 u_int16_t x =
1622 (cmd->opcode == O_IP_SRCPORT) ?
1623 src_port : dst_port ;
1624 u_int16_t *p =
1625 ((ipfw_insn_u16 *)cmd)->ports;
1626 int i;
1627
1628 for (i = cmdlen - 1; !match && i>0;
1629 i--, p += 2)
1630 match = (x>=p[0] && x<=p[1]);
1631 }
1632 break;
1633
1634 case O_ICMPTYPE:
1635 match = (offset == 0 && proto==IPPROTO_ICMP &&
1636 icmptype_match(ICMP(ulp), (ipfw_insn_u32 *)cmd) );
1637 break;
1638
1639 #ifdef INET6
1640 case O_ICMP6TYPE:
1641 match = is_ipv6 && offset == 0 &&
1642 proto==IPPROTO_ICMPV6 &&
1643 icmp6type_match(
1644 ICMP6(ulp)->icmp6_type,
1645 (ipfw_insn_u32 *)cmd);
1646 break;
1647 #endif /* INET6 */
1648
1649 case O_IPOPT:
1650 match = (is_ipv4 &&
1651 ipopts_match(ip, cmd) );
1652 break;
1653
1654 case O_IPVER:
1655 match = (is_ipv4 &&
1656 cmd->arg1 == ip->ip_v);
1657 break;
1658
1659 case O_IPID:
1660 case O_IPLEN:
1661 case O_IPTTL:
1662 if (is_ipv4) { /* only for IP packets */
1663 uint16_t x;
1664 uint16_t *p;
1665 int i;
1666
1667 if (cmd->opcode == O_IPLEN)
1668 x = iplen;
1669 else if (cmd->opcode == O_IPTTL)
1670 x = ip->ip_ttl;
1671 else /* must be IPID */
1672 x = ntohs(ip->ip_id);
1673 if (cmdlen == 1) {
1674 match = (cmd->arg1 == x);
1675 break;
1676 }
1677 /* otherwise we have ranges */
1678 p = ((ipfw_insn_u16 *)cmd)->ports;
1679 i = cmdlen - 1;
1680 for (; !match && i>0; i--, p += 2)
1681 match = (x >= p[0] && x <= p[1]);
1682 }
1683 break;
1684
1685 case O_IPPRECEDENCE:
1686 match = (is_ipv4 &&
1687 (cmd->arg1 == (ip->ip_tos & 0xe0)) );
1688 break;
1689
1690 case O_IPTOS:
1691 match = (is_ipv4 &&
1692 flags_match(cmd, ip->ip_tos));
1693 break;
1694
1695 case O_DSCP:
1696 {
1697 uint32_t *p;
1698 uint16_t x;
1699
1700 p = ((ipfw_insn_u32 *)cmd)->d;
1701
1702 if (is_ipv4)
1703 x = ip->ip_tos >> 2;
1704 else if (is_ipv6) {
1705 uint8_t *v;
1706 v = &((struct ip6_hdr *)ip)->ip6_vfc;
1707 x = (*v & 0x0F) << 2;
1708 v++;
1709 x |= *v >> 6;
1710 } else
1711 break;
1712
1713 /* DSCP bitmask is stored as low_u32 high_u32 */
1714 if (x > 32)
1715 match = *(p + 1) & (1 << (x - 32));
1716 else
1717 match = *p & (1 << x);
1718 }
1719 break;
1720
1721 case O_TCPDATALEN:
1722 if (proto == IPPROTO_TCP && offset == 0) {
1723 struct tcphdr *tcp;
1724 uint16_t x;
1725 uint16_t *p;
1726 int i;
1727
1728 tcp = TCP(ulp);
1729 x = iplen -
1730 ((ip->ip_hl + tcp->th_off) << 2);
1731 if (cmdlen == 1) {
1732 match = (cmd->arg1 == x);
1733 break;
1734 }
1735 /* otherwise we have ranges */
1736 p = ((ipfw_insn_u16 *)cmd)->ports;
1737 i = cmdlen - 1;
1738 for (; !match && i>0; i--, p += 2)
1739 match = (x >= p[0] && x <= p[1]);
1740 }
1741 break;
1742
1743 case O_TCPFLAGS:
1744 match = (proto == IPPROTO_TCP && offset == 0 &&
1745 flags_match(cmd, TCP(ulp)->th_flags));
1746 break;
1747
1748 case O_TCPOPTS:
1749 if (proto == IPPROTO_TCP && offset == 0 && ulp){
1750 PULLUP_LEN(hlen, ulp,
1751 (TCP(ulp)->th_off << 2));
1752 match = tcpopts_match(TCP(ulp), cmd);
1753 }
1754 break;
1755
1756 case O_TCPSEQ:
1757 match = (proto == IPPROTO_TCP && offset == 0 &&
1758 ((ipfw_insn_u32 *)cmd)->d[0] ==
1759 TCP(ulp)->th_seq);
1760 break;
1761
1762 case O_TCPACK:
1763 match = (proto == IPPROTO_TCP && offset == 0 &&
1764 ((ipfw_insn_u32 *)cmd)->d[0] ==
1765 TCP(ulp)->th_ack);
1766 break;
1767
1768 case O_TCPWIN:
1769 if (proto == IPPROTO_TCP && offset == 0) {
1770 uint16_t x;
1771 uint16_t *p;
1772 int i;
1773
1774 x = ntohs(TCP(ulp)->th_win);
1775 if (cmdlen == 1) {
1776 match = (cmd->arg1 == x);
1777 break;
1778 }
1779 /* Otherwise we have ranges. */
1780 p = ((ipfw_insn_u16 *)cmd)->ports;
1781 i = cmdlen - 1;
1782 for (; !match && i > 0; i--, p += 2)
1783 match = (x >= p[0] && x <= p[1]);
1784 }
1785 break;
1786
1787 case O_ESTAB:
1788 /* reject packets which have SYN only */
1789 /* XXX should i also check for TH_ACK ? */
1790 match = (proto == IPPROTO_TCP && offset == 0 &&
1791 (TCP(ulp)->th_flags &
1792 (TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
1793 break;
1794
1795 case O_ALTQ: {
1796 struct pf_mtag *at;
1797 struct m_tag *mtag;
1798 ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd;
1799
1800 /*
1801 * ALTQ uses mbuf tags from another
1802 * packet filtering system - pf(4).
1803 * We allocate a tag in its format
1804 * and fill it in, pretending to be pf(4).
1805 */
1806 match = 1;
1807 at = pf_find_mtag(m);
1808 if (at != NULL && at->qid != 0)
1809 break;
1810 mtag = m_tag_get(PACKET_TAG_PF,
1811 sizeof(struct pf_mtag), M_NOWAIT | M_ZERO);
1812 if (mtag == NULL) {
1813 /*
1814 * Let the packet fall back to the
1815 * default ALTQ.
1816 */
1817 break;
1818 }
1819 m_tag_prepend(m, mtag);
1820 at = (struct pf_mtag *)(mtag + 1);
1821 at->qid = altq->qid;
1822 at->hdr = ip;
1823 break;
1824 }
1825
1826 case O_LOG:
1827 ipfw_log(chain, f, hlen, args, m,
1828 oif, offset | ip6f_mf, tablearg, ip);
1829 match = 1;
1830 break;
1831
1832 case O_PROB:
1833 match = (random()<((ipfw_insn_u32 *)cmd)->d[0]);
1834 break;
1835
1836 case O_VERREVPATH:
1837 /* Outgoing packets automatically pass/match */
1838 match = ((oif != NULL) ||
1839 (m->m_pkthdr.rcvif == NULL) ||
1840 (
1841 #ifdef INET6
1842 is_ipv6 ?
1843 verify_path6(&(args->f_id.src_ip6),
1844 m->m_pkthdr.rcvif, args->f_id.fib) :
1845 #endif
1846 verify_path(src_ip, m->m_pkthdr.rcvif,
1847 args->f_id.fib)));
1848 break;
1849
1850 case O_VERSRCREACH:
1851 /* Outgoing packets automatically pass/match */
1852 match = (hlen > 0 && ((oif != NULL) ||
1853 #ifdef INET6
1854 is_ipv6 ?
1855 verify_path6(&(args->f_id.src_ip6),
1856 NULL, args->f_id.fib) :
1857 #endif
1858 verify_path(src_ip, NULL, args->f_id.fib)));
1859 break;
1860
1861 case O_ANTISPOOF:
1862 /* Outgoing packets automatically pass/match */
1863 if (oif == NULL && hlen > 0 &&
1864 ( (is_ipv4 && in_localaddr(src_ip))
1865 #ifdef INET6
1866 || (is_ipv6 &&
1867 in6_localaddr(&(args->f_id.src_ip6)))
1868 #endif
1869 ))
1870 match =
1871 #ifdef INET6
1872 is_ipv6 ? verify_path6(
1873 &(args->f_id.src_ip6),
1874 m->m_pkthdr.rcvif,
1875 args->f_id.fib) :
1876 #endif
1877 verify_path(src_ip,
1878 m->m_pkthdr.rcvif,
1879 args->f_id.fib);
1880 else
1881 match = 1;
1882 break;
1883
1884 case O_IPSEC:
1885 #ifdef IPSEC
1886 match = (m_tag_find(m,
1887 PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL);
1888 #endif
1889 /* otherwise no match */
1890 break;
1891
1892 #ifdef INET6
1893 case O_IP6_SRC:
1894 match = is_ipv6 &&
1895 IN6_ARE_ADDR_EQUAL(&args->f_id.src_ip6,
1896 &((ipfw_insn_ip6 *)cmd)->addr6);
1897 break;
1898
1899 case O_IP6_DST:
1900 match = is_ipv6 &&
1901 IN6_ARE_ADDR_EQUAL(&args->f_id.dst_ip6,
1902 &((ipfw_insn_ip6 *)cmd)->addr6);
1903 break;
1904 case O_IP6_SRC_MASK:
1905 case O_IP6_DST_MASK:
1906 if (is_ipv6) {
1907 int i = cmdlen - 1;
1908 struct in6_addr p;
1909 struct in6_addr *d =
1910 &((ipfw_insn_ip6 *)cmd)->addr6;
1911
1912 for (; !match && i > 0; d += 2,
1913 i -= F_INSN_SIZE(struct in6_addr)
1914 * 2) {
1915 p = (cmd->opcode ==
1916 O_IP6_SRC_MASK) ?
1917 args->f_id.src_ip6:
1918 args->f_id.dst_ip6;
1919 APPLY_MASK(&p, &d[1]);
1920 match =
1921 IN6_ARE_ADDR_EQUAL(&d[0],
1922 &p);
1923 }
1924 }
1925 break;
1926
1927 case O_FLOW6ID:
1928 match = is_ipv6 &&
1929 flow6id_match(args->f_id.flow_id6,
1930 (ipfw_insn_u32 *) cmd);
1931 break;
1932
1933 case O_EXT_HDR:
1934 match = is_ipv6 &&
1935 (ext_hd & ((ipfw_insn *) cmd)->arg1);
1936 break;
1937
1938 case O_IP6:
1939 match = is_ipv6;
1940 break;
1941 #endif
1942
1943 case O_IP4:
1944 match = is_ipv4;
1945 break;
1946
1947 case O_TAG: {
1948 struct m_tag *mtag;
1949 uint32_t tag = TARG(cmd->arg1, tag);
1950
1951 /* Packet is already tagged with this tag? */
1952 mtag = m_tag_locate(m, MTAG_IPFW, tag, NULL);
1953
1954 /* We have `untag' action when F_NOT flag is
1955 * present. And we must remove this mtag from
1956 * mbuf and reset `match' to zero (`match' will
1957 * be inversed later).
1958 * Otherwise we should allocate new mtag and
1959 * push it into mbuf.
1960 */
1961 if (cmd->len & F_NOT) { /* `untag' action */
1962 if (mtag != NULL)
1963 m_tag_delete(m, mtag);
1964 match = 0;
1965 } else {
1966 if (mtag == NULL) {
1967 mtag = m_tag_alloc( MTAG_IPFW,
1968 tag, 0, M_NOWAIT);
1969 if (mtag != NULL)
1970 m_tag_prepend(m, mtag);
1971 }
1972 match = 1;
1973 }
1974 break;
1975 }
1976
1977 case O_FIB: /* try match the specified fib */
1978 if (args->f_id.fib == cmd->arg1)
1979 match = 1;
1980 break;
1981
1982 case O_SOCKARG: {
1983 #ifndef USERSPACE /* not supported in userspace */
1984 struct inpcb *inp = args->inp;
1985 struct inpcbinfo *pi;
1986
1987 if (is_ipv6) /* XXX can we remove this ? */
1988 break;
1989
1990 if (proto == IPPROTO_TCP)
1991 pi = &V_tcbinfo;
1992 else if (proto == IPPROTO_UDP)
1993 pi = &V_udbinfo;
1994 else
1995 break;
1996
1997 /*
1998 * XXXRW: so_user_cookie should almost
1999 * certainly be inp_user_cookie?
2000 */
2001
2002 /* For incomming packet, lookup up the
2003 inpcb using the src/dest ip/port tuple */
2004 if (inp == NULL) {
2005 inp = in_pcblookup(pi,
2006 src_ip, htons(src_port),
2007 dst_ip, htons(dst_port),
2008 INPLOOKUP_RLOCKPCB, NULL);
2009 if (inp != NULL) {
2010 tablearg =
2011 inp->inp_socket->so_user_cookie;
2012 if (tablearg)
2013 match = 1;
2014 INP_RUNLOCK(inp);
2015 }
2016 } else {
2017 if (inp->inp_socket) {
2018 tablearg =
2019 inp->inp_socket->so_user_cookie;
2020 if (tablearg)
2021 match = 1;
2022 }
2023 }
2024 #endif /* !USERSPACE */
2025 break;
2026 }
2027
2028 case O_TAGGED: {
2029 struct m_tag *mtag;
2030 uint32_t tag = TARG(cmd->arg1, tag);
2031
2032 if (cmdlen == 1) {
2033 match = m_tag_locate(m, MTAG_IPFW,
2034 tag, NULL) != NULL;
2035 break;
2036 }
2037
2038 /* we have ranges */
2039 for (mtag = m_tag_first(m);
2040 mtag != NULL && !match;
2041 mtag = m_tag_next(m, mtag)) {
2042 uint16_t *p;
2043 int i;
2044
2045 if (mtag->m_tag_cookie != MTAG_IPFW)
2046 continue;
2047
2048 p = ((ipfw_insn_u16 *)cmd)->ports;
2049 i = cmdlen - 1;
2050 for(; !match && i > 0; i--, p += 2)
2051 match =
2052 mtag->m_tag_id >= p[0] &&
2053 mtag->m_tag_id <= p[1];
2054 }
2055 break;
2056 }
2057
2058 /*
2059 * The second set of opcodes represents 'actions',
2060 * i.e. the terminal part of a rule once the packet
2061 * matches all previous patterns.
2062 * Typically there is only one action for each rule,
2063 * and the opcode is stored at the end of the rule
2064 * (but there are exceptions -- see below).
2065 *
2066 * In general, here we set retval and terminate the
2067 * outer loop (would be a 'break 3' in some language,
2068 * but we need to set l=0, done=1)
2069 *
2070 * Exceptions:
2071 * O_COUNT and O_SKIPTO actions:
2072 * instead of terminating, we jump to the next rule
2073 * (setting l=0), or to the SKIPTO target (setting
2074 * f/f_len, cmd and l as needed), respectively.
2075 *
2076 * O_TAG, O_LOG and O_ALTQ action parameters:
2077 * perform some action and set match = 1;
2078 *
2079 * O_LIMIT and O_KEEP_STATE: these opcodes are
2080 * not real 'actions', and are stored right
2081 * before the 'action' part of the rule.
2082 * These opcodes try to install an entry in the
2083 * state tables; if successful, we continue with
2084 * the next opcode (match=1; break;), otherwise
2085 * the packet must be dropped (set retval,
2086 * break loops with l=0, done=1)
2087 *
2088 * O_PROBE_STATE and O_CHECK_STATE: these opcodes
2089 * cause a lookup of the state table, and a jump
2090 * to the 'action' part of the parent rule
2091 * if an entry is found, or
2092 * (CHECK_STATE only) a jump to the next rule if
2093 * the entry is not found.
2094 * The result of the lookup is cached so that
2095 * further instances of these opcodes become NOPs.
2096 * The jump to the next rule is done by setting
2097 * l=0, cmdlen=0.
2098 */
2099 case O_LIMIT:
2100 case O_KEEP_STATE:
2101 if (ipfw_install_state(chain, f,
2102 (ipfw_insn_limit *)cmd, args, tablearg)) {
2103 /* error or limit violation */
2104 retval = IP_FW_DENY;
2105 l = 0; /* exit inner loop */
2106 done = 1; /* exit outer loop */
2107 }
2108 match = 1;
2109 break;
2110
2111 case O_PROBE_STATE:
2112 case O_CHECK_STATE:
2113 /*
2114 * dynamic rules are checked at the first
2115 * keep-state or check-state occurrence,
2116 * with the result being stored in dyn_dir.
2117 * The compiler introduces a PROBE_STATE
2118 * instruction for us when we have a
2119 * KEEP_STATE (because PROBE_STATE needs
2120 * to be run first).
2121 */
2122 if (dyn_dir == MATCH_UNKNOWN &&
2123 (q = ipfw_lookup_dyn_rule(&args->f_id,
2124 &dyn_dir, proto == IPPROTO_TCP ?
2125 TCP(ulp) : NULL))
2126 != NULL) {
2127 /*
2128 * Found dynamic entry, update stats
2129 * and jump to the 'action' part of
2130 * the parent rule by setting
2131 * f, cmd, l and clearing cmdlen.
2132 */
2133 IPFW_INC_DYN_COUNTER(q, pktlen);
2134 /* XXX we would like to have f_pos
2135 * readily accessible in the dynamic
2136 * rule, instead of having to
2137 * lookup q->rule.
2138 */
2139 f = q->rule;
2140 f_pos = ipfw_find_rule(chain,
2141 f->rulenum, f->id);
2142 cmd = ACTION_PTR(f);
2143 l = f->cmd_len - f->act_ofs;
2144 ipfw_dyn_unlock(q);
2145 cmdlen = 0;
2146 match = 1;
2147 break;
2148 }
2149 /*
2150 * Dynamic entry not found. If CHECK_STATE,
2151 * skip to next rule, if PROBE_STATE just
2152 * ignore and continue with next opcode.
2153 */
2154 if (cmd->opcode == O_CHECK_STATE)
2155 l = 0; /* exit inner loop */
2156 match = 1;
2157 break;
2158
2159 case O_ACCEPT:
2160 retval = 0; /* accept */
2161 l = 0; /* exit inner loop */
2162 done = 1; /* exit outer loop */
2163 break;
2164
2165 case O_PIPE:
2166 case O_QUEUE:
2167 set_match(args, f_pos, chain);
2168 args->rule.info = TARG(cmd->arg1, pipe);
2169 if (cmd->opcode == O_PIPE)
2170 args->rule.info |= IPFW_IS_PIPE;
2171 if (V_fw_one_pass)
2172 args->rule.info |= IPFW_ONEPASS;
2173 retval = IP_FW_DUMMYNET;
2174 l = 0; /* exit inner loop */
2175 done = 1; /* exit outer loop */
2176 break;
2177
2178 case O_DIVERT:
2179 case O_TEE:
2180 if (args->eh) /* not on layer 2 */
2181 break;
2182 /* otherwise this is terminal */
2183 l = 0; /* exit inner loop */
2184 done = 1; /* exit outer loop */
2185 retval = (cmd->opcode == O_DIVERT) ?
2186 IP_FW_DIVERT : IP_FW_TEE;
2187 set_match(args, f_pos, chain);
2188 args->rule.info = TARG(cmd->arg1, divert);
2189 break;
2190
2191 case O_COUNT:
2192 IPFW_INC_RULE_COUNTER(f, pktlen);
2193 l = 0; /* exit inner loop */
2194 break;
2195
2196 case O_SKIPTO:
2197 IPFW_INC_RULE_COUNTER(f, pktlen);
2198 f_pos = JUMP(chain, f, cmd->arg1, tablearg, 0);
2199 /*
2200 * Skip disabled rules, and re-enter
2201 * the inner loop with the correct
2202 * f_pos, f, l and cmd.
2203 * Also clear cmdlen and skip_or
2204 */
2205 for (; f_pos < chain->n_rules - 1 &&
2206 (V_set_disable &
2207 (1 << chain->map[f_pos]->set));
2208 f_pos++)
2209 ;
2210 /* Re-enter the inner loop at the skipto rule. */
2211 f = chain->map[f_pos];
2212 l = f->cmd_len;
2213 cmd = f->cmd;
2214 match = 1;
2215 cmdlen = 0;
2216 skip_or = 0;
2217 continue;
2218 break; /* not reached */
2219
2220 case O_CALLRETURN: {
2221 /*
2222 * Implementation of `subroutine' call/return,
2223 * in the stack carried in an mbuf tag. This
2224 * is different from `skipto' in that any call
2225 * address is possible (`skipto' must prevent
2226 * backward jumps to avoid endless loops).
2227 * We have `return' action when F_NOT flag is
2228 * present. The `m_tag_id' field is used as
2229 * stack pointer.
2230 */
2231 struct m_tag *mtag;
2232 uint16_t jmpto, *stack;
2233
2234 #define IS_CALL ((cmd->len & F_NOT) == 0)
2235 #define IS_RETURN ((cmd->len & F_NOT) != 0)
2236 /*
2237 * Hand-rolled version of m_tag_locate() with
2238 * wildcard `type'.
2239 * If not already tagged, allocate new tag.
2240 */
2241 mtag = m_tag_first(m);
2242 while (mtag != NULL) {
2243 if (mtag->m_tag_cookie ==
2244 MTAG_IPFW_CALL)
2245 break;
2246 mtag = m_tag_next(m, mtag);
2247 }
2248 if (mtag == NULL && IS_CALL) {
2249 mtag = m_tag_alloc(MTAG_IPFW_CALL, 0,
2250 IPFW_CALLSTACK_SIZE *
2251 sizeof(uint16_t), M_NOWAIT);
2252 if (mtag != NULL)
2253 m_tag_prepend(m, mtag);
2254 }
2255
2256 /*
2257 * On error both `call' and `return' just
2258 * continue with next rule.
2259 */
2260 if (IS_RETURN && (mtag == NULL ||
2261 mtag->m_tag_id == 0)) {
2262 l = 0; /* exit inner loop */
2263 break;
2264 }
2265 if (IS_CALL && (mtag == NULL ||
2266 mtag->m_tag_id >= IPFW_CALLSTACK_SIZE)) {
2267 printf("ipfw: call stack error, "
2268 "go to next rule\n");
2269 l = 0; /* exit inner loop */
2270 break;
2271 }
2272
2273 IPFW_INC_RULE_COUNTER(f, pktlen);
2274 stack = (uint16_t *)(mtag + 1);
2275
2276 /*
2277 * The `call' action may use cached f_pos
2278 * (in f->next_rule), whose version is written
2279 * in f->next_rule.
2280 * The `return' action, however, doesn't have
2281 * fixed jump address in cmd->arg1 and can't use
2282 * cache.
2283 */
2284 if (IS_CALL) {
2285 stack[mtag->m_tag_id] = f->rulenum;
2286 mtag->m_tag_id++;
2287 f_pos = JUMP(chain, f, cmd->arg1,
2288 tablearg, 1);
2289 } else { /* `return' action */
2290 mtag->m_tag_id--;
2291 jmpto = stack[mtag->m_tag_id] + 1;
2292 f_pos = ipfw_find_rule(chain, jmpto, 0);
2293 }
2294
2295 /*
2296 * Skip disabled rules, and re-enter
2297 * the inner loop with the correct
2298 * f_pos, f, l and cmd.
2299 * Also clear cmdlen and skip_or
2300 */
2301 for (; f_pos < chain->n_rules - 1 &&
2302 (V_set_disable &
2303 (1 << chain->map[f_pos]->set)); f_pos++)
2304 ;
2305 /* Re-enter the inner loop at the dest rule. */
2306 f = chain->map[f_pos];
2307 l = f->cmd_len;
2308 cmd = f->cmd;
2309 cmdlen = 0;
2310 skip_or = 0;
2311 continue;
2312 break; /* NOTREACHED */
2313 }
2314 #undef IS_CALL
2315 #undef IS_RETURN
2316
2317 case O_REJECT:
2318 /*
2319 * Drop the packet and send a reject notice
2320 * if the packet is not ICMP (or is an ICMP
2321 * query), and it is not multicast/broadcast.
2322 */
2323 if (hlen > 0 && is_ipv4 && offset == 0 &&
2324 (proto != IPPROTO_ICMP ||
2325 is_icmp_query(ICMP(ulp))) &&
2326 !(m->m_flags & (M_BCAST|M_MCAST)) &&
2327 !IN_MULTICAST(ntohl(dst_ip.s_addr))) {
2328 send_reject(args, cmd->arg1, iplen, ip);
2329 m = args->m;
2330 }
2331 /* FALLTHROUGH */
2332 #ifdef INET6
2333 case O_UNREACH6:
2334 if (hlen > 0 && is_ipv6 &&
2335 ((offset & IP6F_OFF_MASK) == 0) &&
2336 (proto != IPPROTO_ICMPV6 ||
2337 (is_icmp6_query(icmp6_type) == 1)) &&
2338 !(m->m_flags & (M_BCAST|M_MCAST)) &&
2339 !IN6_IS_ADDR_MULTICAST(&args->f_id.dst_ip6)) {
2340 send_reject6(
2341 args, cmd->arg1, hlen,
2342 (struct ip6_hdr *)ip);
2343 m = args->m;
2344 }
2345 /* FALLTHROUGH */
2346 #endif
2347 case O_DENY:
2348 retval = IP_FW_DENY;
2349 l = 0; /* exit inner loop */
2350 done = 1; /* exit outer loop */
2351 break;
2352
2353 case O_FORWARD_IP:
2354 if (args->eh) /* not valid on layer2 pkts */
2355 break;
2356 if (q == NULL || q->rule != f ||
2357 dyn_dir == MATCH_FORWARD) {
2358 struct sockaddr_in *sa;
2359
2360 sa = &(((ipfw_insn_sa *)cmd)->sa);
2361 if (sa->sin_addr.s_addr == INADDR_ANY) {
2362 #ifdef INET6
2363 /*
2364 * We use O_FORWARD_IP opcode for
2365 * fwd rule with tablearg, but tables
2366 * now support IPv6 addresses. And
2367 * when we are inspecting IPv6 packet,
2368 * we can use nh6 field from
2369 * table_value as next_hop6 address.
2370 */
2371 if (is_ipv6) {
2372 struct sockaddr_in6 *sa6;
2373
2374 sa6 = args->next_hop6 =
2375 &args->hopstore6;
2376 sa6->sin6_family = AF_INET6;
2377 sa6->sin6_len = sizeof(*sa6);
2378 sa6->sin6_addr = TARG_VAL(
2379 chain, tablearg, nh6);
2380 /*
2381 * Set sin6_scope_id only for
2382 * link-local unicast addresses.
2383 */
2384 if (IN6_IS_ADDR_LINKLOCAL(
2385 &sa6->sin6_addr))
2386 sa6->sin6_scope_id =
2387 TARG_VAL(chain,
2388 tablearg,
2389 zoneid);
2390 } else
2391 #endif
2392 {
2393 sa = args->next_hop =
2394 &args->hopstore;
2395 sa->sin_family = AF_INET;
2396 sa->sin_len = sizeof(*sa);
2397 sa->sin_addr.s_addr = htonl(
2398 TARG_VAL(chain, tablearg,
2399 nh4));
2400 }
2401 } else {
2402 args->next_hop = sa;
2403 }
2404 }
2405 retval = IP_FW_PASS;
2406 l = 0; /* exit inner loop */
2407 done = 1; /* exit outer loop */
2408 break;
2409
2410 #ifdef INET6
2411 case O_FORWARD_IP6:
2412 if (args->eh) /* not valid on layer2 pkts */
2413 break;
2414 if (q == NULL || q->rule != f ||
2415 dyn_dir == MATCH_FORWARD) {
2416 struct sockaddr_in6 *sin6;
2417
2418 sin6 = &(((ipfw_insn_sa6 *)cmd)->sa);
2419 args->next_hop6 = sin6;
2420 }
2421 retval = IP_FW_PASS;
2422 l = 0; /* exit inner loop */
2423 done = 1; /* exit outer loop */
2424 break;
2425 #endif
2426
2427 case O_NETGRAPH:
2428 case O_NGTEE:
2429 set_match(args, f_pos, chain);
2430 args->rule.info = TARG(cmd->arg1, netgraph);
2431 if (V_fw_one_pass)
2432 args->rule.info |= IPFW_ONEPASS;
2433 retval = (cmd->opcode == O_NETGRAPH) ?
2434 IP_FW_NETGRAPH : IP_FW_NGTEE;
2435 l = 0; /* exit inner loop */
2436 done = 1; /* exit outer loop */
2437 break;
2438
2439 case O_SETFIB: {
2440 uint32_t fib;
2441
2442 IPFW_INC_RULE_COUNTER(f, pktlen);
2443 fib = TARG(cmd->arg1, fib) & 0x7FFF;
2444 if (fib >= rt_numfibs)
2445 fib = 0;
2446 M_SETFIB(m, fib);
2447 args->f_id.fib = fib;
2448 l = 0; /* exit inner loop */
2449 break;
2450 }
2451
2452 case O_SETDSCP: {
2453 uint16_t code;
2454
2455 code = TARG(cmd->arg1, dscp) & 0x3F;
2456 l = 0; /* exit inner loop */
2457 if (is_ipv4) {
2458 uint16_t old;
2459
2460 old = *(uint16_t *)ip;
2461 ip->ip_tos = (code << 2) |
2462 (ip->ip_tos & 0x03);
2463 ip->ip_sum = cksum_adjust(ip->ip_sum,
2464 old, *(uint16_t *)ip);
2465 } else if (is_ipv6) {
2466 uint8_t *v;
2467
2468 v = &((struct ip6_hdr *)ip)->ip6_vfc;
2469 *v = (*v & 0xF0) | (code >> 2);
2470 v++;
2471 *v = (*v & 0x3F) | ((code & 0x03) << 6);
2472 } else
2473 break;
2474
2475 IPFW_INC_RULE_COUNTER(f, pktlen);
2476 break;
2477 }
2478
2479 case O_NAT:
2480 l = 0; /* exit inner loop */
2481 done = 1; /* exit outer loop */
2482 if (!IPFW_NAT_LOADED) {
2483 retval = IP_FW_DENY;
2484 break;
2485 }
2486
2487 struct cfg_nat *t;
2488 int nat_id;
2489
2490 set_match(args, f_pos, chain);
2491 /* Check if this is 'global' nat rule */
2492 if (cmd->arg1 == 0) {
2493 retval = ipfw_nat_ptr(args, NULL, m);
2494 break;
2495 }
2496 t = ((ipfw_insn_nat *)cmd)->nat;
2497 if (t == NULL) {
2498 nat_id = TARG(cmd->arg1, nat);
2499 t = (*lookup_nat_ptr)(&chain->nat, nat_id);
2500
2501 if (t == NULL) {
2502 retval = IP_FW_DENY;
2503 break;
2504 }
2505 if (cmd->arg1 != IP_FW_TARG)
2506 ((ipfw_insn_nat *)cmd)->nat = t;
2507 }
2508 retval = ipfw_nat_ptr(args, t, m);
2509 break;
2510
2511 case O_REASS: {
2512 int ip_off;
2513
2514 IPFW_INC_RULE_COUNTER(f, pktlen);
2515 l = 0; /* in any case exit inner loop */
2516 ip_off = ntohs(ip->ip_off);
2517
2518 /* if not fragmented, go to next rule */
2519 if ((ip_off & (IP_MF | IP_OFFMASK)) == 0)
2520 break;
2521
2522 args->m = m = ip_reass(m);
2523
2524 /*
2525 * do IP header checksum fixup.
2526 */
2527 if (m == NULL) { /* fragment got swallowed */
2528 retval = IP_FW_DENY;
2529 } else { /* good, packet complete */
2530 int hlen;
2531
2532 ip = mtod(m, struct ip *);
2533 hlen = ip->ip_hl << 2;
2534 ip->ip_sum = 0;
2535 if (hlen == sizeof(struct ip))
2536 ip->ip_sum = in_cksum_hdr(ip);
2537 else
2538 ip->ip_sum = in_cksum(m, hlen);
2539 retval = IP_FW_REASS;
2540 set_match(args, f_pos, chain);
2541 }
2542 done = 1; /* exit outer loop */
2543 break;
2544 }
2545
2546 default:
2547 panic("-- unknown opcode %d\n", cmd->opcode);
2548 } /* end of switch() on opcodes */
2549 /*
2550 * if we get here with l=0, then match is irrelevant.
2551 */
2552
2553 if (cmd->len & F_NOT)
2554 match = !match;
2555
2556 if (match) {
2557 if (cmd->len & F_OR)
2558 skip_or = 1;
2559 } else {
2560 if (!(cmd->len & F_OR)) /* not an OR block, */
2561 break; /* try next rule */
2562 }
2563
2564 } /* end of inner loop, scan opcodes */
2565 #undef PULLUP_LEN
2566
2567 if (done)
2568 break;
2569
2570 /* next_rule:; */ /* try next rule */
2571
2572 } /* end of outer for, scan rules */
2573
2574 if (done) {
2575 struct ip_fw *rule = chain->map[f_pos];
2576 /* Update statistics */
2577 IPFW_INC_RULE_COUNTER(rule, pktlen);
2578 } else {
2579 retval = IP_FW_DENY;
2580 printf("ipfw: ouch!, skip past end of rules, denying packet\n");
2581 }
2582 IPFW_PF_RUNLOCK(chain);
2583 #ifdef __FreeBSD__
2584 if (ucred_cache != NULL)
2585 crfree(ucred_cache);
2586 #endif
2587 return (retval);
2588
2589 pullup_failed:
2590 if (V_fw_verbose)
2591 printf("ipfw: pullup failed\n");
2592 return (IP_FW_DENY);
2593 }
2594
2595 /*
2596 * Set maximum number of tables that can be used in given VNET ipfw instance.
2597 */
2598 #ifdef SYSCTL_NODE
2599 static int
sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS)2600 sysctl_ipfw_table_num(SYSCTL_HANDLER_ARGS)
2601 {
2602 int error;
2603 unsigned int ntables;
2604
2605 ntables = V_fw_tables_max;
2606
2607 error = sysctl_handle_int(oidp, &ntables, 0, req);
2608 /* Read operation or some error */
2609 if ((error != 0) || (req->newptr == NULL))
2610 return (error);
2611
2612 return (ipfw_resize_tables(&V_layer3_chain, ntables));
2613 }
2614
2615 /*
2616 * Switches table namespace between global and per-set.
2617 */
2618 static int
sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS)2619 sysctl_ipfw_tables_sets(SYSCTL_HANDLER_ARGS)
2620 {
2621 int error;
2622 unsigned int sets;
2623
2624 sets = V_fw_tables_sets;
2625
2626 error = sysctl_handle_int(oidp, &sets, 0, req);
2627 /* Read operation or some error */
2628 if ((error != 0) || (req->newptr == NULL))
2629 return (error);
2630
2631 return (ipfw_switch_tables_namespace(&V_layer3_chain, sets));
2632 }
2633 #endif
2634
2635 /*
2636 * Module and VNET glue
2637 */
2638
2639 /*
2640 * Stuff that must be initialised only on boot or module load
2641 */
2642 static int
ipfw_init(void)2643 ipfw_init(void)
2644 {
2645 int error = 0;
2646
2647 /*
2648 * Only print out this stuff the first time around,
2649 * when called from the sysinit code.
2650 */
2651 printf("ipfw2 "
2652 #ifdef INET6
2653 "(+ipv6) "
2654 #endif
2655 "initialized, divert %s, nat %s, "
2656 "default to %s, logging ",
2657 #ifdef IPDIVERT
2658 "enabled",
2659 #else
2660 "loadable",
2661 #endif
2662 #ifdef IPFIREWALL_NAT
2663 "enabled",
2664 #else
2665 "loadable",
2666 #endif
2667 default_to_accept ? "accept" : "deny");
2668
2669 /*
2670 * Note: V_xxx variables can be accessed here but the vnet specific
2671 * initializer may not have been called yet for the VIMAGE case.
2672 * Tuneables will have been processed. We will print out values for
2673 * the default vnet.
2674 * XXX This should all be rationalized AFTER 8.0
2675 */
2676 if (V_fw_verbose == 0)
2677 printf("disabled\n");
2678 else if (V_verbose_limit == 0)
2679 printf("unlimited\n");
2680 else
2681 printf("limited to %d packets/entry by default\n",
2682 V_verbose_limit);
2683
2684 /* Check user-supplied table count for validness */
2685 if (default_fw_tables > IPFW_TABLES_MAX)
2686 default_fw_tables = IPFW_TABLES_MAX;
2687
2688 ipfw_init_sopt_handler();
2689 ipfw_log_bpf(1); /* init */
2690 ipfw_iface_init();
2691 return (error);
2692 }
2693
2694 /*
2695 * Called for the removal of the last instance only on module unload.
2696 */
2697 static void
ipfw_destroy(void)2698 ipfw_destroy(void)
2699 {
2700
2701 ipfw_iface_destroy();
2702 ipfw_log_bpf(0); /* uninit */
2703 ipfw_destroy_sopt_handler();
2704 printf("IP firewall unloaded\n");
2705 }
2706
2707 /*
2708 * Stuff that must be initialized for every instance
2709 * (including the first of course).
2710 */
2711 static int
vnet_ipfw_init(const void * unused)2712 vnet_ipfw_init(const void *unused)
2713 {
2714 int error, first;
2715 struct ip_fw *rule = NULL;
2716 struct ip_fw_chain *chain;
2717
2718 chain = &V_layer3_chain;
2719
2720 first = IS_DEFAULT_VNET(curvnet) ? 1 : 0;
2721
2722 /* First set up some values that are compile time options */
2723 V_autoinc_step = 100; /* bounded to 1..1000 in add_rule() */
2724 V_fw_deny_unknown_exthdrs = 1;
2725 #ifdef IPFIREWALL_VERBOSE
2726 V_fw_verbose = 1;
2727 #endif
2728 #ifdef IPFIREWALL_VERBOSE_LIMIT
2729 V_verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
2730 #endif
2731 #ifdef IPFIREWALL_NAT
2732 LIST_INIT(&chain->nat);
2733 #endif
2734
2735 /* Init shared services hash table */
2736 ipfw_init_srv(chain);
2737
2738 ipfw_init_obj_rewriter();
2739 ipfw_init_counters();
2740 /* insert the default rule and create the initial map */
2741 chain->n_rules = 1;
2742 chain->map = malloc(sizeof(struct ip_fw *), M_IPFW, M_WAITOK | M_ZERO);
2743 rule = ipfw_alloc_rule(chain, sizeof(struct ip_fw));
2744
2745 /* Set initial number of tables */
2746 V_fw_tables_max = default_fw_tables;
2747 error = ipfw_init_tables(chain, first);
2748 if (error) {
2749 printf("ipfw2: setting up tables failed\n");
2750 free(chain->map, M_IPFW);
2751 free(rule, M_IPFW);
2752 return (ENOSPC);
2753 }
2754
2755 /* fill and insert the default rule */
2756 rule->act_ofs = 0;
2757 rule->rulenum = IPFW_DEFAULT_RULE;
2758 rule->cmd_len = 1;
2759 rule->set = RESVD_SET;
2760 rule->cmd[0].len = 1;
2761 rule->cmd[0].opcode = default_to_accept ? O_ACCEPT : O_DENY;
2762 chain->default_rule = chain->map[0] = rule;
2763 chain->id = rule->id = 1;
2764 /* Pre-calculate rules length for legacy dump format */
2765 chain->static_len = sizeof(struct ip_fw_rule0);
2766
2767 IPFW_LOCK_INIT(chain);
2768 ipfw_dyn_init(chain);
2769 #ifdef LINEAR_SKIPTO
2770 ipfw_init_skipto_cache(chain);
2771 #endif
2772
2773 /* First set up some values that are compile time options */
2774 V_ipfw_vnet_ready = 1; /* Open for business */
2775
2776 /*
2777 * Hook the sockopt handler and pfil hooks for ipv4 and ipv6.
2778 * Even if the latter two fail we still keep the module alive
2779 * because the sockopt and layer2 paths are still useful.
2780 * ipfw[6]_hook return 0 on success, ENOENT on failure,
2781 * so we can ignore the exact return value and just set a flag.
2782 *
2783 * Note that V_fw[6]_enable are manipulated by a SYSCTL_PROC so
2784 * changes in the underlying (per-vnet) variables trigger
2785 * immediate hook()/unhook() calls.
2786 * In layer2 we have the same behaviour, except that V_ether_ipfw
2787 * is checked on each packet because there are no pfil hooks.
2788 */
2789 V_ip_fw_ctl_ptr = ipfw_ctl3;
2790 error = ipfw_attach_hooks(1);
2791 return (error);
2792 }
2793
2794 /*
2795 * Called for the removal of each instance.
2796 */
2797 static int
vnet_ipfw_uninit(const void * unused)2798 vnet_ipfw_uninit(const void *unused)
2799 {
2800 struct ip_fw *reap;
2801 struct ip_fw_chain *chain = &V_layer3_chain;
2802 int i, last;
2803
2804 V_ipfw_vnet_ready = 0; /* tell new callers to go away */
2805 /*
2806 * disconnect from ipv4, ipv6, layer2 and sockopt.
2807 * Then grab, release and grab again the WLOCK so we make
2808 * sure the update is propagated and nobody will be in.
2809 */
2810 (void)ipfw_attach_hooks(0 /* detach */);
2811 V_ip_fw_ctl_ptr = NULL;
2812
2813 last = IS_DEFAULT_VNET(curvnet) ? 1 : 0;
2814
2815 IPFW_UH_WLOCK(chain);
2816 IPFW_UH_WUNLOCK(chain);
2817
2818 ipfw_dyn_uninit(0); /* run the callout_drain */
2819
2820 IPFW_UH_WLOCK(chain);
2821
2822 reap = NULL;
2823 IPFW_WLOCK(chain);
2824 for (i = 0; i < chain->n_rules; i++)
2825 ipfw_reap_add(chain, &reap, chain->map[i]);
2826 free(chain->map, M_IPFW);
2827 #ifdef LINEAR_SKIPTO
2828 ipfw_destroy_skipto_cache(chain);
2829 #endif
2830 IPFW_WUNLOCK(chain);
2831 IPFW_UH_WUNLOCK(chain);
2832 ipfw_destroy_tables(chain, last);
2833 if (reap != NULL)
2834 ipfw_reap_rules(reap);
2835 vnet_ipfw_iface_destroy(chain);
2836 ipfw_destroy_srv(chain);
2837 IPFW_LOCK_DESTROY(chain);
2838 ipfw_dyn_uninit(1); /* free the remaining parts */
2839 ipfw_destroy_counters();
2840 ipfw_destroy_obj_rewriter();
2841 return (0);
2842 }
2843
2844 /*
2845 * Module event handler.
2846 * In general we have the choice of handling most of these events by the
2847 * event handler or by the (VNET_)SYS(UN)INIT handlers. I have chosen to
2848 * use the SYSINIT handlers as they are more capable of expressing the
2849 * flow of control during module and vnet operations, so this is just
2850 * a skeleton. Note there is no SYSINIT equivalent of the module
2851 * SHUTDOWN handler, but we don't have anything to do in that case anyhow.
2852 */
2853 static int
ipfw_modevent(module_t mod,int type,void * unused)2854 ipfw_modevent(module_t mod, int type, void *unused)
2855 {
2856 int err = 0;
2857
2858 switch (type) {
2859 case MOD_LOAD:
2860 /* Called once at module load or
2861 * system boot if compiled in. */
2862 break;
2863 case MOD_QUIESCE:
2864 /* Called before unload. May veto unloading. */
2865 break;
2866 case MOD_UNLOAD:
2867 /* Called during unload. */
2868 break;
2869 case MOD_SHUTDOWN:
2870 /* Called during system shutdown. */
2871 break;
2872 default:
2873 err = EOPNOTSUPP;
2874 break;
2875 }
2876 return err;
2877 }
2878
2879 static moduledata_t ipfwmod = {
2880 "ipfw",
2881 ipfw_modevent,
2882 0
2883 };
2884
2885 /* Define startup order. */
2886 #define IPFW_SI_SUB_FIREWALL SI_SUB_PROTO_IFATTACHDOMAIN
2887 #define IPFW_MODEVENT_ORDER (SI_ORDER_ANY - 255) /* On boot slot in here. */
2888 #define IPFW_MODULE_ORDER (IPFW_MODEVENT_ORDER + 1) /* A little later. */
2889 #define IPFW_VNET_ORDER (IPFW_MODEVENT_ORDER + 2) /* Later still. */
2890
2891 DECLARE_MODULE(ipfw, ipfwmod, IPFW_SI_SUB_FIREWALL, IPFW_MODEVENT_ORDER);
2892 FEATURE(ipfw_ctl3, "ipfw new sockopt calls");
2893 MODULE_VERSION(ipfw, 3);
2894 /* should declare some dependencies here */
2895
2896 /*
2897 * Starting up. Done in order after ipfwmod() has been called.
2898 * VNET_SYSINIT is also called for each existing vnet and each new vnet.
2899 */
2900 SYSINIT(ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
2901 ipfw_init, NULL);
2902 VNET_SYSINIT(vnet_ipfw_init, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
2903 vnet_ipfw_init, NULL);
2904
2905 /*
2906 * Closing up shop. These are done in REVERSE ORDER, but still
2907 * after ipfwmod() has been called. Not called on reboot.
2908 * VNET_SYSUNINIT is also called for each exiting vnet as it exits.
2909 * or when the module is unloaded.
2910 */
2911 SYSUNINIT(ipfw_destroy, IPFW_SI_SUB_FIREWALL, IPFW_MODULE_ORDER,
2912 ipfw_destroy, NULL);
2913 VNET_SYSUNINIT(vnet_ipfw_uninit, IPFW_SI_SUB_FIREWALL, IPFW_VNET_ORDER,
2914 vnet_ipfw_uninit, NULL);
2915 /* end of file */
2916