1 /* $OpenBSD: filter.c,v 1.1 2005/12/28 19:07:07 jcs Exp $ */
5 * Copyright (c) 2004, 2005 Camiel Dobbelaar, <cd@sentia.nl>
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
22 #include <sys/ioctl.h>
23 #include <sys/types.h>
24 #include <sys/socket.h>
27 #include <net/pfvar.h>
28 #include <netinet/in.h>
29 #include <netinet/tcp.h>
30 #include <arpa/inet.h>
42 /* From netinet/in.h, but only _KERNEL_ gets them. */
43 #define satosin(sa) ((struct sockaddr_in *)(sa))
44 #define satosin6(sa) ((struct sockaddr_in6 *)(sa))
46 enum { TRANS_FILTER = 0, TRANS_NAT, TRANS_RDR, TRANS_SIZE };
48 int prepare_rule(u_int32_t, int, struct sockaddr *, struct sockaddr *,
50 int server_lookup4(struct sockaddr_in *, struct sockaddr_in *,
51 struct sockaddr_in *, u_int8_t);
52 int server_lookup6(struct sockaddr_in6 *, struct sockaddr_in6 *,
53 struct sockaddr_in6 *, u_int8_t);
55 static struct pfioc_pooladdr pfp;
56 static struct pfioc_rule pfr;
57 static struct pfioc_trans pft;
58 static struct pfioc_trans_e pfte[TRANS_SIZE];
59 static int dev, rule_log;
63 add_filter(u_int32_t id, u_int8_t dir, struct sockaddr *src,
64 struct sockaddr *dst, u_int16_t d_port, u_int8_t proto)
66 if (!src || !dst || !d_port || !proto) {
71 if (prepare_rule(id, PF_RULESET_FILTER, src, dst, d_port, proto) == -1)
74 pfr.rule.direction = dir;
75 if (ioctl(dev, DIOCADDRULE, &pfr) == -1)
82 add_nat(u_int32_t id, struct sockaddr *src, struct sockaddr *dst,
83 u_int16_t d_port, struct sockaddr *nat, u_int16_t nat_range_low,
84 u_int16_t nat_range_high, u_int8_t proto)
86 if (!src || !dst || !d_port || !nat || !nat_range_low || !proto ||
87 (src->sa_family != nat->sa_family)) {
92 if (prepare_rule(id, PF_RULESET_NAT, src, dst, d_port, proto) == -1)
95 if (nat->sa_family == AF_INET) {
96 memcpy(&pfp.addr.addr.v.a.addr.v4,
97 &satosin(nat)->sin_addr.s_addr, 4);
98 memset(&pfp.addr.addr.v.a.mask.addr8, 255, 4);
100 memcpy(&pfp.addr.addr.v.a.addr.v6,
101 &satosin6(nat)->sin6_addr.s6_addr, 16);
102 memset(&pfp.addr.addr.v.a.mask.addr8, 255, 16);
104 if (ioctl(dev, DIOCADDADDR, &pfp) == -1)
107 pfr.rule.rpool.proxy_port[0] = nat_range_low;
108 pfr.rule.rpool.proxy_port[1] = nat_range_high;
109 if (ioctl(dev, DIOCADDRULE, &pfr) == -1)
116 add_rdr(u_int32_t id, struct sockaddr *src, struct sockaddr *dst,
117 u_int16_t d_port, struct sockaddr *rdr, u_int16_t rdr_port, u_int8_t proto)
119 if (!src || !dst || !d_port || !rdr || !rdr_port || !proto ||
120 (src->sa_family != rdr->sa_family)) {
125 if (prepare_rule(id, PF_RULESET_RDR, src, dst, d_port, proto) == -1)
128 if (rdr->sa_family == AF_INET) {
129 memcpy(&pfp.addr.addr.v.a.addr.v4,
130 &satosin(rdr)->sin_addr.s_addr, 4);
131 memset(&pfp.addr.addr.v.a.mask.addr8, 255, 4);
133 memcpy(&pfp.addr.addr.v.a.addr.v6,
134 &satosin6(rdr)->sin6_addr.s6_addr, 16);
135 memset(&pfp.addr.addr.v.a.mask.addr8, 255, 16);
137 if (ioctl(dev, DIOCADDADDR, &pfp) == -1)
140 pfr.rule.rpool.proxy_port[0] = rdr_port;
141 if (ioctl(dev, DIOCADDRULE, &pfr) == -1)
150 if (ioctl(dev, DIOCXCOMMIT, &pft) == -1)
159 if (ioctl(dev, DIOCXROLLBACK, &pft) == -1)
166 init_filter(char *opt_qname, int opt_verbose)
168 struct pf_status status;
172 if (opt_verbose == 1)
174 else if (opt_verbose == 2)
175 rule_log = PF_LOG_ALL;
177 dev = open("/dev/pf", O_RDWR);
179 syslog(LOG_ERR, "can't open /dev/pf");
182 if (ioctl(dev, DIOCGETSTATUS, &status) == -1) {
183 syslog(LOG_ERR, "DIOCGETSTATUS");
186 if (!status.running) {
187 syslog(LOG_ERR, "pf is disabled");
193 prepare_commit(u_int32_t id)
195 char an[PF_ANCHOR_NAME_SIZE];
198 memset(&pft, 0, sizeof pft);
199 pft.size = TRANS_SIZE;
200 pft.esize = sizeof pfte[0];
203 snprintf(an, PF_ANCHOR_NAME_SIZE, "%s/%d.%d", FTP_PROXY_ANCHOR,
205 for (i = 0; i < TRANS_SIZE; i++) {
206 memset(&pfte[i], 0, sizeof pfte[0]);
207 strlcpy(pfte[i].anchor, an, PF_ANCHOR_NAME_SIZE);
210 pfte[i].rs_num = PF_RULESET_FILTER;
213 pfte[i].rs_num = PF_RULESET_NAT;
216 pfte[i].rs_num = PF_RULESET_RDR;
224 if (ioctl(dev, DIOCXBEGIN, &pft) == -1)
231 prepare_rule(u_int32_t id, int rs_num, struct sockaddr *src,
232 struct sockaddr *dst, u_int16_t d_port, u_int8_t proto)
234 char an[PF_ANCHOR_NAME_SIZE];
236 if ((src->sa_family != AF_INET && src->sa_family != AF_INET6) ||
237 (src->sa_family != dst->sa_family)) {
238 errno = EPROTONOSUPPORT;
242 memset(&pfp, 0, sizeof pfp);
243 memset(&pfr, 0, sizeof pfr);
244 snprintf(an, PF_ANCHOR_NAME_SIZE, "%s/%d.%d", FTP_PROXY_ANCHOR,
246 strlcpy(pfp.anchor, an, PF_ANCHOR_NAME_SIZE);
247 strlcpy(pfr.anchor, an, PF_ANCHOR_NAME_SIZE);
250 case PF_RULESET_FILTER:
251 pfr.ticket = pfte[TRANS_FILTER].ticket;
254 pfr.ticket = pfte[TRANS_NAT].ticket;
257 pfr.ticket = pfte[TRANS_RDR].ticket;
263 if (ioctl(dev, DIOCBEGINADDRS, &pfp) == -1)
265 pfr.pool_ticket = pfp.ticket;
267 /* Generic for all rule types. */
268 pfr.rule.af = src->sa_family;
269 pfr.rule.proto = proto;
270 pfr.rule.src.addr.type = PF_ADDR_ADDRMASK;
271 pfr.rule.dst.addr.type = PF_ADDR_ADDRMASK;
272 if (src->sa_family == AF_INET) {
273 memcpy(&pfr.rule.src.addr.v.a.addr.v4,
274 &satosin(src)->sin_addr.s_addr, 4);
275 memset(&pfr.rule.src.addr.v.a.mask.addr8, 255, 4);
276 memcpy(&pfr.rule.dst.addr.v.a.addr.v4,
277 &satosin(dst)->sin_addr.s_addr, 4);
278 memset(&pfr.rule.dst.addr.v.a.mask.addr8, 255, 4);
280 memcpy(&pfr.rule.src.addr.v.a.addr.v6,
281 &satosin6(src)->sin6_addr.s6_addr, 16);
282 memset(&pfr.rule.src.addr.v.a.mask.addr8, 255, 16);
283 memcpy(&pfr.rule.dst.addr.v.a.addr.v6,
284 &satosin6(dst)->sin6_addr.s6_addr, 16);
285 memset(&pfr.rule.dst.addr.v.a.mask.addr8, 255, 16);
287 pfr.rule.dst.port_op = PF_OP_EQ;
288 pfr.rule.dst.port[0] = htons(d_port);
291 case PF_RULESET_FILTER:
293 * pass quick [log] inet[6] proto tcp \
294 * from $src to $dst port = $d_port flags S/SAFR keep state
295 * (max 1) [queue qname]
297 pfr.rule.action = PF_PASS;
299 pfr.rule.log = rule_log;
300 pfr.rule.keep_state = 1;
302 pfr.rule.flags = (proto == IPPROTO_TCP ? TH_SYN : 0);
303 pfr.rule.flagset = (proto == IPPROTO_TCP ?
304 (TH_SYN|TH_ACK|TH_FIN|TH_RST) : 0);
306 pfr.rule.flags = (proto == IPPROTO_TCP ? TH_SYN : NULL);
307 pfr.rule.flagset = (proto == IPPROTO_TCP ?
308 (TH_SYN|TH_ACK|TH_FIN|TH_RST) : NULL);
310 pfr.rule.max_states = 1;
312 strlcpy(pfr.rule.qname, qname, sizeof pfr.rule.qname);
316 * nat inet[6] proto tcp from $src to $dst port $d_port -> $nat
318 pfr.rule.action = PF_NAT;
322 * rdr inet[6] proto tcp from $src to $dst port $d_port -> $rdr
324 pfr.rule.action = PF_RDR;
335 server_lookup(struct sockaddr *client, struct sockaddr *proxy,
336 struct sockaddr *server, u_int8_t proto)
338 if (client->sa_family == AF_INET)
339 return (server_lookup4(satosin(client), satosin(proxy),
340 satosin(server), proto));
342 if (client->sa_family == AF_INET6)
343 return (server_lookup6(satosin6(client), satosin6(proxy),
344 satosin6(server), proto));
346 errno = EPROTONOSUPPORT;
351 server_lookup4(struct sockaddr_in *client, struct sockaddr_in *proxy,
352 struct sockaddr_in *server, u_int8_t proto)
354 struct pfioc_natlook pnl;
356 memset(&pnl, 0, sizeof pnl);
357 pnl.direction = PF_OUT;
360 memcpy(&pnl.saddr.v4, &client->sin_addr.s_addr, sizeof pnl.saddr.v4);
361 memcpy(&pnl.daddr.v4, &proxy->sin_addr.s_addr, sizeof pnl.daddr.v4);
362 pnl.sport = client->sin_port;
363 pnl.dport = proxy->sin_port;
365 if (ioctl(dev, DIOCNATLOOK, &pnl) == -1)
368 memset(server, 0, sizeof(struct sockaddr_in));
369 server->sin_len = sizeof(struct sockaddr_in);
370 server->sin_family = AF_INET;
371 memcpy(&server->sin_addr.s_addr, &pnl.rdaddr.v4,
372 sizeof server->sin_addr.s_addr);
373 server->sin_port = pnl.rdport;
379 server_lookup6(struct sockaddr_in6 *client, struct sockaddr_in6 *proxy,
380 struct sockaddr_in6 *server, u_int8_t proto)
382 struct pfioc_natlook pnl;
384 memset(&pnl, 0, sizeof pnl);
385 pnl.direction = PF_OUT;
388 memcpy(&pnl.saddr.v6, &client->sin6_addr.s6_addr, sizeof pnl.saddr.v6);
389 memcpy(&pnl.daddr.v6, &proxy->sin6_addr.s6_addr, sizeof pnl.daddr.v6);
390 pnl.sport = client->sin6_port;
391 pnl.dport = proxy->sin6_port;
393 if (ioctl(dev, DIOCNATLOOK, &pnl) == -1)
396 memset(server, 0, sizeof(struct sockaddr_in6));
397 server->sin6_len = sizeof(struct sockaddr_in6);
398 server->sin6_family = AF_INET6;
399 memcpy(&server->sin6_addr.s6_addr, &pnl.rdaddr.v6,
400 sizeof server->sin6_addr);
401 server->sin6_port = pnl.rdport;