1 /* $OpenBSD: filter.c,v 1.5 2006/12/01 07:31:21 camield Exp $ */
4 * Copyright (c) 2004, 2005 Camiel Dobbelaar, <cd@sentia.nl>
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
19 #include <sys/ioctl.h>
20 #include <sys/types.h>
21 #include <sys/socket.h>
24 #include <net/pfvar.h>
25 #include <netinet/in.h>
26 #include <netinet/tcp.h>
27 #include <arpa/inet.h>
38 /* From netinet/in.h, but only _KERNEL_ gets them. */
39 #define satosin(sa) ((struct sockaddr_in *)(sa))
40 #define satosin6(sa) ((struct sockaddr_in6 *)(sa))
42 enum { TRANS_FILTER = 0, TRANS_NAT, TRANS_RDR, TRANS_SIZE };
44 int prepare_rule(u_int32_t, int, struct sockaddr *, struct sockaddr *,
46 int server_lookup4(struct sockaddr_in *, struct sockaddr_in *,
47 struct sockaddr_in *);
48 int server_lookup6(struct sockaddr_in6 *, struct sockaddr_in6 *,
49 struct sockaddr_in6 *);
51 static struct pfioc_pooladdr pfp;
52 static struct pfioc_rule pfr;
53 static struct pfioc_trans pft;
54 static struct pfioc_trans_e pfte[TRANS_SIZE];
55 static int dev, rule_log;
59 add_filter(u_int32_t id, u_int8_t dir, struct sockaddr *src,
60 struct sockaddr *dst, u_int16_t d_port)
62 if (!src || !dst || !d_port) {
67 if (prepare_rule(id, PF_RULESET_FILTER, src, dst, d_port) == -1)
70 pfr.rule.direction = dir;
71 if (ioctl(dev, DIOCADDRULE, &pfr) == -1)
78 add_nat(u_int32_t id, struct sockaddr *src, struct sockaddr *dst,
79 u_int16_t d_port, struct sockaddr *nat, u_int16_t nat_range_low,
80 u_int16_t nat_range_high)
82 if (!src || !dst || !d_port || !nat || !nat_range_low ||
83 (src->sa_family != nat->sa_family)) {
88 if (prepare_rule(id, PF_RULESET_NAT, src, dst, d_port) == -1)
91 if (nat->sa_family == AF_INET) {
92 memcpy(&pfp.addr.addr.v.a.addr.v4,
93 &satosin(nat)->sin_addr.s_addr, 4);
94 memset(&pfp.addr.addr.v.a.mask.addr8, 255, 4);
96 memcpy(&pfp.addr.addr.v.a.addr.v6,
97 &satosin6(nat)->sin6_addr.s6_addr, 16);
98 memset(&pfp.addr.addr.v.a.mask.addr8, 255, 16);
100 if (ioctl(dev, DIOCADDADDR, &pfp) == -1)
103 pfr.rule.rpool.proxy_port[0] = nat_range_low;
104 pfr.rule.rpool.proxy_port[1] = nat_range_high;
105 if (ioctl(dev, DIOCADDRULE, &pfr) == -1)
112 add_rdr(u_int32_t id, struct sockaddr *src, struct sockaddr *dst,
113 u_int16_t d_port, struct sockaddr *rdr, u_int16_t rdr_port)
115 if (!src || !dst || !d_port || !rdr || !rdr_port ||
116 (src->sa_family != rdr->sa_family)) {
121 if (prepare_rule(id, PF_RULESET_RDR, src, dst, d_port) == -1)
124 if (rdr->sa_family == AF_INET) {
125 memcpy(&pfp.addr.addr.v.a.addr.v4,
126 &satosin(rdr)->sin_addr.s_addr, 4);
127 memset(&pfp.addr.addr.v.a.mask.addr8, 255, 4);
129 memcpy(&pfp.addr.addr.v.a.addr.v6,
130 &satosin6(rdr)->sin6_addr.s6_addr, 16);
131 memset(&pfp.addr.addr.v.a.mask.addr8, 255, 16);
133 if (ioctl(dev, DIOCADDADDR, &pfp) == -1)
136 pfr.rule.rpool.proxy_port[0] = rdr_port;
137 if (ioctl(dev, DIOCADDRULE, &pfr) == -1)
146 if (ioctl(dev, DIOCXCOMMIT, &pft) == -1)
155 if (ioctl(dev, DIOCXROLLBACK, &pft) == -1)
162 init_filter(char *opt_qname, int opt_verbose)
164 struct pf_status status;
168 if (opt_verbose == 1)
170 else if (opt_verbose == 2)
171 rule_log = PF_LOG_ALL;
173 dev = open("/dev/pf", O_RDWR);
176 if (ioctl(dev, DIOCGETSTATUS, &status) == -1)
177 err(1, "DIOCGETSTATUS");
179 errx(1, "pf is disabled");
183 prepare_commit(u_int32_t id)
185 char an[PF_ANCHOR_NAME_SIZE];
188 memset(&pft, 0, sizeof pft);
189 pft.size = TRANS_SIZE;
190 pft.esize = sizeof pfte[0];
193 snprintf(an, PF_ANCHOR_NAME_SIZE, "%s/%d.%d", FTP_PROXY_ANCHOR,
195 for (i = 0; i < TRANS_SIZE; i++) {
196 memset(&pfte[i], 0, sizeof pfte[0]);
197 strlcpy(pfte[i].anchor, an, PF_ANCHOR_NAME_SIZE);
200 pfte[i].rs_num = PF_RULESET_FILTER;
203 pfte[i].rs_num = PF_RULESET_NAT;
206 pfte[i].rs_num = PF_RULESET_RDR;
214 if (ioctl(dev, DIOCXBEGIN, &pft) == -1)
221 prepare_rule(u_int32_t id, int rs_num, struct sockaddr *src,
222 struct sockaddr *dst, u_int16_t d_port)
224 char an[PF_ANCHOR_NAME_SIZE];
226 if ((src->sa_family != AF_INET && src->sa_family != AF_INET6) ||
227 (src->sa_family != dst->sa_family)) {
228 errno = EPROTONOSUPPORT;
232 memset(&pfp, 0, sizeof pfp);
233 memset(&pfr, 0, sizeof pfr);
234 snprintf(an, PF_ANCHOR_NAME_SIZE, "%s/%d.%d", FTP_PROXY_ANCHOR,
236 strlcpy(pfp.anchor, an, PF_ANCHOR_NAME_SIZE);
237 strlcpy(pfr.anchor, an, PF_ANCHOR_NAME_SIZE);
240 case PF_RULESET_FILTER:
241 pfr.ticket = pfte[TRANS_FILTER].ticket;
244 pfr.ticket = pfte[TRANS_NAT].ticket;
247 pfr.ticket = pfte[TRANS_RDR].ticket;
253 if (ioctl(dev, DIOCBEGINADDRS, &pfp) == -1)
255 pfr.pool_ticket = pfp.ticket;
257 /* Generic for all rule types. */
258 pfr.rule.af = src->sa_family;
259 pfr.rule.proto = IPPROTO_TCP;
260 pfr.rule.src.addr.type = PF_ADDR_ADDRMASK;
261 pfr.rule.dst.addr.type = PF_ADDR_ADDRMASK;
262 if (src->sa_family == AF_INET) {
263 memcpy(&pfr.rule.src.addr.v.a.addr.v4,
264 &satosin(src)->sin_addr.s_addr, 4);
265 memset(&pfr.rule.src.addr.v.a.mask.addr8, 255, 4);
266 memcpy(&pfr.rule.dst.addr.v.a.addr.v4,
267 &satosin(dst)->sin_addr.s_addr, 4);
268 memset(&pfr.rule.dst.addr.v.a.mask.addr8, 255, 4);
270 memcpy(&pfr.rule.src.addr.v.a.addr.v6,
271 &satosin6(src)->sin6_addr.s6_addr, 16);
272 memset(&pfr.rule.src.addr.v.a.mask.addr8, 255, 16);
273 memcpy(&pfr.rule.dst.addr.v.a.addr.v6,
274 &satosin6(dst)->sin6_addr.s6_addr, 16);
275 memset(&pfr.rule.dst.addr.v.a.mask.addr8, 255, 16);
277 pfr.rule.dst.port_op = PF_OP_EQ;
278 pfr.rule.dst.port[0] = htons(d_port);
281 case PF_RULESET_FILTER:
283 * pass quick [log] inet[6] proto tcp \
284 * from $src to $dst port = $d_port flags S/SA keep state
285 * (max 1) [queue qname]
287 pfr.rule.action = PF_PASS;
289 pfr.rule.log = rule_log;
290 pfr.rule.keep_state = 1;
291 pfr.rule.flags = TH_SYN;
292 pfr.rule.flagset = (TH_SYN|TH_ACK);
293 pfr.rule.max_states = 1;
295 strlcpy(pfr.rule.qname, qname, sizeof pfr.rule.qname);
299 * nat inet[6] proto tcp from $src to $dst port $d_port -> $nat
301 pfr.rule.action = PF_NAT;
305 * rdr inet[6] proto tcp from $src to $dst port $d_port -> $rdr
307 pfr.rule.action = PF_RDR;
318 server_lookup(struct sockaddr *client, struct sockaddr *proxy,
319 struct sockaddr *server)
321 if (client->sa_family == AF_INET)
322 return (server_lookup4(satosin(client), satosin(proxy),
325 if (client->sa_family == AF_INET6)
326 return (server_lookup6(satosin6(client), satosin6(proxy),
329 errno = EPROTONOSUPPORT;
334 server_lookup4(struct sockaddr_in *client, struct sockaddr_in *proxy,
335 struct sockaddr_in *server)
337 struct pfioc_natlook pnl;
339 memset(&pnl, 0, sizeof pnl);
340 pnl.direction = PF_OUT;
342 pnl.proto = IPPROTO_TCP;
343 memcpy(&pnl.saddr.v4, &client->sin_addr.s_addr, sizeof pnl.saddr.v4);
344 memcpy(&pnl.daddr.v4, &proxy->sin_addr.s_addr, sizeof pnl.daddr.v4);
345 pnl.sport = client->sin_port;
346 pnl.dport = proxy->sin_port;
348 if (ioctl(dev, DIOCNATLOOK, &pnl) == -1)
351 memset(server, 0, sizeof(struct sockaddr_in));
352 server->sin_len = sizeof(struct sockaddr_in);
353 server->sin_family = AF_INET;
354 memcpy(&server->sin_addr.s_addr, &pnl.rdaddr.v4,
355 sizeof server->sin_addr.s_addr);
356 server->sin_port = pnl.rdport;
362 server_lookup6(struct sockaddr_in6 *client, struct sockaddr_in6 *proxy,
363 struct sockaddr_in6 *server)
365 struct pfioc_natlook pnl;
367 memset(&pnl, 0, sizeof pnl);
368 pnl.direction = PF_OUT;
370 pnl.proto = IPPROTO_TCP;
371 memcpy(&pnl.saddr.v6, &client->sin6_addr.s6_addr, sizeof pnl.saddr.v6);
372 memcpy(&pnl.daddr.v6, &proxy->sin6_addr.s6_addr, sizeof pnl.daddr.v6);
373 pnl.sport = client->sin6_port;
374 pnl.dport = proxy->sin6_port;
376 if (ioctl(dev, DIOCNATLOOK, &pnl) == -1)
379 memset(server, 0, sizeof(struct sockaddr_in6));
380 server->sin6_len = sizeof(struct sockaddr_in6);
381 server->sin6_family = AF_INET6;
382 memcpy(&server->sin6_addr.s6_addr, &pnl.rdaddr.v6,
383 sizeof server->sin6_addr);
384 server->sin6_port = pnl.rdport;