1 /* $OpenBSD: filter.c,v 1.8 2008/06/13 07:25:26 claudio 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>
39 /* From netinet/in.h, but only _KERNEL_ gets them. */
40 #define satosin(sa) ((struct sockaddr_in *)(sa))
41 #define satosin6(sa) ((struct sockaddr_in6 *)(sa))
43 enum { TRANS_FILTER = 0, TRANS_NAT, TRANS_RDR, TRANS_SIZE };
45 int prepare_rule(u_int32_t, int, struct sockaddr *, struct sockaddr *,
47 int server_lookup4(struct sockaddr_in *, struct sockaddr_in *,
48 struct sockaddr_in *);
49 int server_lookup6(struct sockaddr_in6 *, struct sockaddr_in6 *,
50 struct sockaddr_in6 *);
52 static struct pfioc_pooladdr pfp;
53 static struct pfctl_rule pfrule;
54 static char pfanchor[PF_ANCHOR_NAME_SIZE];
55 static char pfanchor_call[PF_ANCHOR_NAME_SIZE];
56 static uint32_t pfticket;
57 static uint32_t pfpool_ticket;
58 static struct pfioc_trans pft;
59 static struct pfioc_trans_e pfte[TRANS_SIZE];
60 static int dev, rule_log;
61 static const char *qname, *tagname;
64 add_filter(u_int32_t id, u_int8_t dir, struct sockaddr *src,
65 struct sockaddr *dst, u_int16_t d_port)
67 if (!src || !dst || !d_port) {
72 if (prepare_rule(id, PF_RULESET_FILTER, src, dst, d_port) == -1)
75 pfrule.direction = dir;
76 if (pfctl_add_rule(dev, &pfrule, pfanchor, pfanchor_call,
77 pfticket, pfpool_ticket))
84 add_nat(u_int32_t id, struct sockaddr *src, struct sockaddr *dst,
85 u_int16_t d_port, struct sockaddr *nat, u_int16_t nat_range_low,
86 u_int16_t nat_range_high)
88 if (!src || !dst || !d_port || !nat || !nat_range_low ||
89 (src->sa_family != nat->sa_family)) {
94 if (prepare_rule(id, PF_RULESET_NAT, src, dst, d_port) == -1)
97 if (nat->sa_family == AF_INET) {
98 memcpy(&pfp.addr.addr.v.a.addr.v4,
99 &satosin(nat)->sin_addr.s_addr, 4);
100 memset(&pfp.addr.addr.v.a.mask.addr8, 255, 4);
102 memcpy(&pfp.addr.addr.v.a.addr.v6,
103 &satosin6(nat)->sin6_addr.s6_addr, 16);
104 memset(&pfp.addr.addr.v.a.mask.addr8, 255, 16);
106 if (pfctl_add_rule(dev, &pfrule, pfanchor, pfanchor_call,
107 pfticket, pfpool_ticket))
110 pfrule.rpool.proxy_port[0] = nat_range_low;
111 pfrule.rpool.proxy_port[1] = nat_range_high;
112 if (pfctl_add_rule(dev, &pfrule, pfanchor, pfanchor_call,
113 pfticket, pfpool_ticket))
120 add_rdr(u_int32_t id, struct sockaddr *src, struct sockaddr *dst,
121 u_int16_t d_port, struct sockaddr *rdr, u_int16_t rdr_port)
123 if (!src || !dst || !d_port || !rdr || !rdr_port ||
124 (src->sa_family != rdr->sa_family)) {
129 if (prepare_rule(id, PF_RULESET_RDR, src, dst, d_port) == -1)
132 if (rdr->sa_family == AF_INET) {
133 memcpy(&pfp.addr.addr.v.a.addr.v4,
134 &satosin(rdr)->sin_addr.s_addr, 4);
135 memset(&pfp.addr.addr.v.a.mask.addr8, 255, 4);
137 memcpy(&pfp.addr.addr.v.a.addr.v6,
138 &satosin6(rdr)->sin6_addr.s6_addr, 16);
139 memset(&pfp.addr.addr.v.a.mask.addr8, 255, 16);
141 if (pfctl_add_rule(dev, &pfrule, pfanchor, pfanchor_call,
142 pfticket, pfpool_ticket))
145 pfrule.rpool.proxy_port[0] = rdr_port;
146 if (pfctl_add_rule(dev, &pfrule, pfanchor, pfanchor_call,
147 pfticket, pfpool_ticket))
156 if (ioctl(dev, DIOCXCOMMIT, &pft) == -1)
165 if (ioctl(dev, DIOCXROLLBACK, &pft) == -1)
172 init_filter(const char *opt_qname, const char *opt_tagname, int opt_verbose)
174 struct pf_status status;
177 tagname = opt_tagname;
179 if (opt_verbose == 1)
181 else if (opt_verbose == 2)
182 rule_log = PF_LOG_ALL;
184 dev = open("/dev/pf", O_RDWR);
186 err(1, "open /dev/pf");
187 if (ioctl(dev, DIOCGETSTATUS, &status) == -1)
188 err(1, "DIOCGETSTATUS");
190 errx(1, "pf is disabled");
194 prepare_commit(u_int32_t id)
196 char an[PF_ANCHOR_NAME_SIZE];
199 memset(&pft, 0, sizeof pft);
200 pft.size = TRANS_SIZE;
201 pft.esize = sizeof pfte[0];
204 snprintf(an, PF_ANCHOR_NAME_SIZE, "%s/%d.%d", FTP_PROXY_ANCHOR,
206 for (i = 0; i < TRANS_SIZE; i++) {
207 memset(&pfte[i], 0, sizeof pfte[0]);
208 strlcpy(pfte[i].anchor, an, PF_ANCHOR_NAME_SIZE);
211 pfte[i].rs_num = PF_RULESET_FILTER;
214 pfte[i].rs_num = PF_RULESET_NAT;
217 pfte[i].rs_num = PF_RULESET_RDR;
225 if (ioctl(dev, DIOCXBEGIN, &pft) == -1)
232 prepare_rule(u_int32_t id, int rs_num, struct sockaddr *src,
233 struct sockaddr *dst, u_int16_t d_port)
235 char an[PF_ANCHOR_NAME_SIZE];
237 if ((src->sa_family != AF_INET && src->sa_family != AF_INET6) ||
238 (src->sa_family != dst->sa_family)) {
239 errno = EPROTONOSUPPORT;
243 memset(&pfp, 0, sizeof pfp);
244 memset(&pfrule, 0, sizeof pfrule);
245 snprintf(an, PF_ANCHOR_NAME_SIZE, "%s/%d.%d", FTP_PROXY_ANCHOR,
247 strlcpy(pfp.anchor, an, PF_ANCHOR_NAME_SIZE);
248 strlcpy(pfanchor, an, PF_ANCHOR_NAME_SIZE);
251 case PF_RULESET_FILTER:
252 pfticket = pfte[TRANS_FILTER].ticket;
255 pfticket = pfte[TRANS_NAT].ticket;
258 pfticket = pfte[TRANS_RDR].ticket;
264 if (ioctl(dev, DIOCBEGINADDRS, &pfp) == -1)
266 pfpool_ticket = pfp.ticket;
268 /* Generic for all rule types. */
269 pfrule.af = src->sa_family;
270 pfrule.proto = IPPROTO_TCP;
271 pfrule.src.addr.type = PF_ADDR_ADDRMASK;
272 pfrule.dst.addr.type = PF_ADDR_ADDRMASK;
273 if (src->sa_family == AF_INET) {
274 memcpy(&pfrule.src.addr.v.a.addr.v4,
275 &satosin(src)->sin_addr.s_addr, 4);
276 memset(&pfrule.src.addr.v.a.mask.addr8, 255, 4);
277 memcpy(&pfrule.dst.addr.v.a.addr.v4,
278 &satosin(dst)->sin_addr.s_addr, 4);
279 memset(&pfrule.dst.addr.v.a.mask.addr8, 255, 4);
281 memcpy(&pfrule.src.addr.v.a.addr.v6,
282 &satosin6(src)->sin6_addr.s6_addr, 16);
283 memset(&pfrule.src.addr.v.a.mask.addr8, 255, 16);
284 memcpy(&pfrule.dst.addr.v.a.addr.v6,
285 &satosin6(dst)->sin6_addr.s6_addr, 16);
286 memset(&pfrule.dst.addr.v.a.mask.addr8, 255, 16);
288 pfrule.dst.port_op = PF_OP_EQ;
289 pfrule.dst.port[0] = htons(d_port);
292 case PF_RULESET_FILTER:
294 * pass [quick] [log] inet[6] proto tcp \
295 * from $src to $dst port = $d_port flags S/SA keep state
296 * (max 1) [queue qname] [tag tagname]
298 pfrule.action = PF_PASS;
300 pfrule.log = rule_log;
301 pfrule.keep_state = 1;
302 pfrule.flags = TH_SYN;
303 pfrule.flagset = (TH_SYN|TH_ACK);
304 pfrule.max_states = 1;
306 strlcpy(pfrule.qname, qname, sizeof pfrule.qname);
307 if (tagname != NULL) {
309 strlcpy(pfrule.tagname, tagname,
310 sizeof pfrule.tagname);
315 * nat inet[6] proto tcp from $src to $dst port $d_port -> $nat
317 pfrule.action = PF_NAT;
321 * rdr inet[6] proto tcp from $src to $dst port $d_port -> $rdr
323 pfrule.action = PF_RDR;
334 server_lookup(struct sockaddr *client, struct sockaddr *proxy,
335 struct sockaddr *server)
337 if (client->sa_family == AF_INET)
338 return (server_lookup4(satosin(client), satosin(proxy),
341 if (client->sa_family == AF_INET6)
342 return (server_lookup6(satosin6(client), satosin6(proxy),
345 errno = EPROTONOSUPPORT;
350 server_lookup4(struct sockaddr_in *client, struct sockaddr_in *proxy,
351 struct sockaddr_in *server)
353 struct pfioc_natlook pnl;
355 memset(&pnl, 0, sizeof pnl);
356 pnl.direction = PF_OUT;
358 pnl.proto = IPPROTO_TCP;
359 memcpy(&pnl.saddr.v4, &client->sin_addr.s_addr, sizeof pnl.saddr.v4);
360 memcpy(&pnl.daddr.v4, &proxy->sin_addr.s_addr, sizeof pnl.daddr.v4);
361 pnl.sport = client->sin_port;
362 pnl.dport = proxy->sin_port;
364 if (ioctl(dev, DIOCNATLOOK, &pnl) == -1)
367 memset(server, 0, sizeof(struct sockaddr_in));
368 server->sin_len = sizeof(struct sockaddr_in);
369 server->sin_family = AF_INET;
370 memcpy(&server->sin_addr.s_addr, &pnl.rdaddr.v4,
371 sizeof server->sin_addr.s_addr);
372 server->sin_port = pnl.rdport;
378 server_lookup6(struct sockaddr_in6 *client, struct sockaddr_in6 *proxy,
379 struct sockaddr_in6 *server)
381 struct pfioc_natlook pnl;
383 memset(&pnl, 0, sizeof pnl);
384 pnl.direction = PF_OUT;
386 pnl.proto = IPPROTO_TCP;
387 memcpy(&pnl.saddr.v6, &client->sin6_addr.s6_addr, sizeof pnl.saddr.v6);
388 memcpy(&pnl.daddr.v6, &proxy->sin6_addr.s6_addr, sizeof pnl.daddr.v6);
389 pnl.sport = client->sin6_port;
390 pnl.dport = proxy->sin6_port;
392 if (ioctl(dev, DIOCNATLOOK, &pnl) == -1)
395 memset(server, 0, sizeof(struct sockaddr_in6));
396 server->sin6_len = sizeof(struct sockaddr_in6);
397 server->sin6_family = AF_INET6;
398 memcpy(&server->sin6_addr.s6_addr, &pnl.rdaddr.v6,
399 sizeof server->sin6_addr);
400 server->sin6_port = pnl.rdport;