/* $OpenBSD: filter.c,v 1.20 2012/09/18 10:11:53 henning Exp $ */ /* * Copyright (c) 2004, 2005 Camiel Dobbelaar, * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above * copyright notice and this permission notice appear in all copies. * * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "filter.h" /* From netinet/in.h, but only _KERNEL_ gets them. */ #define satosin(sa) ((struct sockaddr_in *)(sa)) #define satosin6(sa) ((struct sockaddr_in6 *)(sa)) int add_addr(struct sockaddr *, struct pf_pool *); int prepare_rule(u_int32_t, struct sockaddr *, struct sockaddr *, u_int16_t); static struct pfioc_rule pfr; static struct pfioc_trans pft; static struct pfioc_trans_e pfte; static int dev, rule_log; static char *qname, *tagname; int add_addr(struct sockaddr *addr, struct pf_pool *pfp) { if (addr->sa_family == AF_INET) { memcpy(&pfp->addr.v.a.addr.v4, &satosin(addr)->sin_addr.s_addr, 4); memset(&pfp->addr.v.a.mask.addr8, 255, 4); } else { memcpy(&pfp->addr.v.a.addr.v6, &satosin6(addr)->sin6_addr.s6_addr, 16); memset(&pfp->addr.v.a.mask.addr8, 255, 16); } pfp->addr.type = PF_ADDR_ADDRMASK; return (0); } int add_nat(u_int32_t id, struct sockaddr *src, int s_rd, struct sockaddr *dst, u_int16_t d_port, struct sockaddr *nat, u_int16_t nat_range_low, u_int16_t nat_range_high) { if (!src || !dst || !d_port || !nat || !nat_range_low || !nat_range_high || (src->sa_family != nat->sa_family)) { errno = EINVAL; return (-1); } if (prepare_rule(id, src, dst, d_port) == -1) return (-1); if (add_addr(nat, &pfr.rule.nat) == -1) return (-1); pfr.rule.direction = PF_OUT; pfr.rule.onrdomain = s_rd; pfr.rule.rtableid = -1; pfr.rule.nat.proxy_port[0] = nat_range_low; pfr.rule.nat.proxy_port[1] = nat_range_high; if (ioctl(dev, DIOCADDRULE, &pfr) == -1) return (-1); return (0); } int add_rdr(u_int32_t id, struct sockaddr *src, int s_rd, struct sockaddr *dst, u_int16_t d_port, struct sockaddr *rdr, u_int16_t rdr_port, int d_rd) { if (!src || !dst || !d_port || !rdr || !rdr_port || (src->sa_family != rdr->sa_family)) { errno = EINVAL; return (-1); } if (prepare_rule(id, src, dst, d_port) == -1) return (-1); if (add_addr(rdr, &pfr.rule.rdr) == -1) return (-1); pfr.rule.direction = PF_IN; pfr.rule.onrdomain = s_rd; pfr.rule.rtableid = d_rd; pfr.rule.rdr.proxy_port[0] = rdr_port; if (ioctl(dev, DIOCADDRULE, &pfr) == -1) return (-1); return (0); } int do_commit(void) { if (ioctl(dev, DIOCXCOMMIT, &pft) == -1) return (-1); return (0); } int do_rollback(void) { if (ioctl(dev, DIOCXROLLBACK, &pft) == -1) return (-1); return (0); } void init_filter(char *opt_qname, char *opt_tagname, int opt_verbose) { struct pf_status status; qname = opt_qname; tagname = opt_tagname; if (opt_verbose == 1) rule_log = PF_LOG; else if (opt_verbose == 2) rule_log = PF_LOG_ALL; dev = open("/dev/pf", O_RDWR); if (dev == -1) err(1, "open /dev/pf"); if (ioctl(dev, DIOCGETSTATUS, &status) == -1) err(1, "DIOCGETSTATUS"); if (!status.running) errx(1, "pf is disabled"); } int prepare_commit(u_int32_t id) { char an[PF_ANCHOR_NAME_SIZE]; memset(&pft, 0, sizeof pft); pft.size = 1; pft.esize = sizeof pfte; pft.array = &pfte; snprintf(an, PF_ANCHOR_NAME_SIZE, "%s/%d.%d", FTP_PROXY_ANCHOR, getpid(), id); memset(&pfte, 0, sizeof pfte); strlcpy(pfte.anchor, an, PF_ANCHOR_NAME_SIZE); pfte.type = PF_TRANS_RULESET; if (ioctl(dev, DIOCXBEGIN, &pft) == -1) return (-1); return (0); } int prepare_rule(u_int32_t id, struct sockaddr *src, struct sockaddr *dst, u_int16_t d_port) { char an[PF_ANCHOR_NAME_SIZE]; if ((src->sa_family != AF_INET && src->sa_family != AF_INET6) || (src->sa_family != dst->sa_family)) { errno = EPROTONOSUPPORT; return (-1); } memset(&pfr, 0, sizeof pfr); snprintf(an, PF_ANCHOR_NAME_SIZE, "%s/%d.%d", FTP_PROXY_ANCHOR, getpid(), id); strlcpy(pfr.anchor, an, PF_ANCHOR_NAME_SIZE); pfr.ticket = pfte.ticket; /* Generic for all rule types. */ pfr.rule.af = src->sa_family; pfr.rule.proto = IPPROTO_TCP; pfr.rule.src.addr.type = PF_ADDR_ADDRMASK; pfr.rule.dst.addr.type = PF_ADDR_ADDRMASK; pfr.rule.nat.addr.type = PF_ADDR_NONE; pfr.rule.rdr.addr.type = PF_ADDR_NONE; if (src->sa_family == AF_INET) { memcpy(&pfr.rule.src.addr.v.a.addr.v4, &satosin(src)->sin_addr.s_addr, 4); memset(&pfr.rule.src.addr.v.a.mask.addr8, 255, 4); memcpy(&pfr.rule.dst.addr.v.a.addr.v4, &satosin(dst)->sin_addr.s_addr, 4); memset(&pfr.rule.dst.addr.v.a.mask.addr8, 255, 4); } else { memcpy(&pfr.rule.src.addr.v.a.addr.v6, &satosin6(src)->sin6_addr.s6_addr, 16); memset(&pfr.rule.src.addr.v.a.mask.addr8, 255, 16); memcpy(&pfr.rule.dst.addr.v.a.addr.v6, &satosin6(dst)->sin6_addr.s6_addr, 16); memset(&pfr.rule.dst.addr.v.a.mask.addr8, 255, 16); } pfr.rule.dst.port_op = PF_OP_EQ; pfr.rule.dst.port[0] = htons(d_port); /* * pass [quick] [log] inet[6] proto tcp \ * from $src to $dst port = $d_port flags S/SA keep state * (max 1) [queue qname] [tag tagname] */ if (tagname != NULL) pfr.rule.action = PF_MATCH; else pfr.rule.action = PF_PASS; pfr.rule.quick = 1; pfr.rule.log = rule_log; pfr.rule.keep_state = 1; pfr.rule.flags = TH_SYN; pfr.rule.flagset = (TH_SYN|TH_ACK); pfr.rule.max_states = 1; if (qname != NULL) strlcpy(pfr.rule.qname, qname, sizeof pfr.rule.qname); if (tagname != NULL) { pfr.rule.quick = 0; strlcpy(pfr.rule.tagname, tagname, sizeof pfr.rule.tagname); } return (0); }