1 /*- 2 * The authors of this code are John Ioannidis (ji@tla.org), 3 * Angelos D. Keromytis (kermit@csd.uch.gr) and 4 * Niels Provos (provos@physnet.uni-hamburg.de). 5 * 6 * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 7 * in November 1995. 8 * 9 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, 10 * by Angelos D. Keromytis. 11 * 12 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis 13 * and Niels Provos. 14 * 15 * Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis 16 * and Niels Provos. 17 * Copyright (c) 2001, Angelos D. Keromytis, Niels Provos. 18 * 19 * Permission to use, copy, and modify this software with or without fee 20 * is hereby granted, provided that this entire notice is included in 21 * all copies of any software which is or includes a copy or 22 * modification of this software. 23 * You may use this code under the GNU public license if you so wish. Please 24 * contribute changes back to the authors under this freer than GPL license 25 * so that we may further the use of strong encryption without limitations to 26 * all. 27 * 28 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 29 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 30 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 31 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 32 * PURPOSE. 33 * 34 * $OpenBSD: if_pflog.c,v 1.26 2007/10/18 21:58:18 mpf Exp $ 35 */ 36 37 #include <sys/cdefs.h> 38 __FBSDID("$FreeBSD$"); 39 40 #include "opt_inet.h" 41 #include "opt_inet6.h" 42 #include "opt_bpf.h" 43 #include "opt_pf.h" 44 45 #include <sys/param.h> 46 #include <sys/kernel.h> 47 #include <sys/mbuf.h> 48 #include <sys/module.h> 49 #include <sys/proc.h> 50 #include <sys/socket.h> 51 #include <sys/sockio.h> 52 53 #include <net/bpf.h> 54 #include <net/if.h> 55 #include <net/if_var.h> 56 #include <net/if_clone.h> 57 #include <net/if_pflog.h> 58 #include <net/if_types.h> 59 #include <net/vnet.h> 60 #include <net/pfvar.h> 61 62 #if defined(INET) || defined(INET6) 63 #include <netinet/in.h> 64 #endif 65 #ifdef INET 66 #include <netinet/in_var.h> 67 #include <netinet/ip.h> 68 #endif 69 70 #ifdef INET6 71 #include <netinet6/in6_var.h> 72 #include <netinet6/nd6.h> 73 #endif /* INET6 */ 74 75 #ifdef INET 76 #include <machine/in_cksum.h> 77 #endif /* INET */ 78 79 #define PFLOGMTU (32768 + MHLEN + MLEN) 80 81 #ifdef PFLOGDEBUG 82 #define DPRINTF(x) do { if (pflogdebug) printf x ; } while (0) 83 #else 84 #define DPRINTF(x) 85 #endif 86 87 static int pflogoutput(struct ifnet *, struct mbuf *, 88 const struct sockaddr *, struct route *); 89 static void pflogattach(int); 90 static int pflogioctl(struct ifnet *, u_long, caddr_t); 91 static void pflogstart(struct ifnet *); 92 static int pflog_clone_create(struct if_clone *, int, caddr_t); 93 static void pflog_clone_destroy(struct ifnet *); 94 static struct if_clone *pflog_cloner; 95 96 static const char pflogname[] = "pflog"; 97 98 struct ifnet *pflogifs[PFLOGIFS_MAX]; /* for fast access */ 99 100 static void 101 pflogattach(int npflog) 102 { 103 int i; 104 for (i = 0; i < PFLOGIFS_MAX; i++) 105 pflogifs[i] = NULL; 106 pflog_cloner = if_clone_simple(pflogname, pflog_clone_create, 107 pflog_clone_destroy, 1); 108 } 109 110 static int 111 pflog_clone_create(struct if_clone *ifc, int unit, caddr_t param) 112 { 113 struct ifnet *ifp; 114 115 if (unit >= PFLOGIFS_MAX) 116 return (EINVAL); 117 118 ifp = if_alloc(IFT_PFLOG); 119 if (ifp == NULL) { 120 return (ENOSPC); 121 } 122 if_initname(ifp, pflogname, unit); 123 ifp->if_mtu = PFLOGMTU; 124 ifp->if_ioctl = pflogioctl; 125 ifp->if_output = pflogoutput; 126 ifp->if_start = pflogstart; 127 ifp->if_snd.ifq_maxlen = ifqmaxlen; 128 ifp->if_hdrlen = PFLOG_HDRLEN; 129 if_attach(ifp); 130 131 bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN); 132 133 pflogifs[unit] = ifp; 134 135 return (0); 136 } 137 138 static void 139 pflog_clone_destroy(struct ifnet *ifp) 140 { 141 int i; 142 143 for (i = 0; i < PFLOGIFS_MAX; i++) 144 if (pflogifs[i] == ifp) 145 pflogifs[i] = NULL; 146 147 bpfdetach(ifp); 148 if_detach(ifp); 149 if_free(ifp); 150 } 151 152 /* 153 * Start output on the pflog interface. 154 */ 155 static void 156 pflogstart(struct ifnet *ifp) 157 { 158 struct mbuf *m; 159 160 for (;;) { 161 IF_LOCK(&ifp->if_snd); 162 _IF_DROP(&ifp->if_snd); 163 _IF_DEQUEUE(&ifp->if_snd, m); 164 IF_UNLOCK(&ifp->if_snd); 165 166 if (m == NULL) 167 return; 168 else 169 m_freem(m); 170 } 171 } 172 173 static int 174 pflogoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 175 struct route *rt) 176 { 177 m_freem(m); 178 return (0); 179 } 180 181 /* ARGSUSED */ 182 static int 183 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 184 { 185 switch (cmd) { 186 case SIOCSIFFLAGS: 187 if (ifp->if_flags & IFF_UP) 188 ifp->if_drv_flags |= IFF_DRV_RUNNING; 189 else 190 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 191 break; 192 default: 193 return (ENOTTY); 194 } 195 196 return (0); 197 } 198 199 static int 200 pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir, 201 u_int8_t reason, struct pf_rule *rm, struct pf_rule *am, 202 struct pf_ruleset *ruleset, struct pf_pdesc *pd, int lookupsafe) 203 { 204 struct ifnet *ifn; 205 struct pfloghdr hdr; 206 207 if (kif == NULL || m == NULL || rm == NULL || pd == NULL) 208 return ( 1); 209 210 if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf) 211 return (0); 212 213 bzero(&hdr, sizeof(hdr)); 214 hdr.length = PFLOG_REAL_HDRLEN; 215 hdr.af = af; 216 hdr.action = rm->action; 217 hdr.reason = reason; 218 memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname)); 219 220 if (am == NULL) { 221 hdr.rulenr = htonl(rm->nr); 222 hdr.subrulenr = 1; 223 } else { 224 hdr.rulenr = htonl(am->nr); 225 hdr.subrulenr = htonl(rm->nr); 226 if (ruleset != NULL && ruleset->anchor != NULL) 227 strlcpy(hdr.ruleset, ruleset->anchor->name, 228 sizeof(hdr.ruleset)); 229 } 230 /* 231 * XXXGL: we avoid pf_socket_lookup() when we are holding 232 * state lock, since this leads to unsafe LOR. 233 * These conditions are very very rare, however. 234 */ 235 if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done && lookupsafe) 236 pd->lookup.done = pf_socket_lookup(dir, pd, m); 237 if (pd->lookup.done > 0) 238 hdr.uid = pd->lookup.uid; 239 else 240 hdr.uid = UID_MAX; 241 hdr.pid = NO_PID; 242 hdr.rule_uid = rm->cuid; 243 hdr.rule_pid = rm->cpid; 244 hdr.dir = dir; 245 246 #ifdef INET 247 if (af == AF_INET && dir == PF_OUT) { 248 struct ip *ip; 249 250 ip = mtod(m, struct ip *); 251 ip->ip_sum = 0; 252 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 253 } 254 #endif /* INET */ 255 256 ifn->if_opackets++; 257 ifn->if_obytes += m->m_pkthdr.len; 258 BPF_MTAP2(ifn, &hdr, PFLOG_HDRLEN, m); 259 260 return (0); 261 } 262 263 static int 264 pflog_modevent(module_t mod, int type, void *data) 265 { 266 int error = 0; 267 268 switch (type) { 269 case MOD_LOAD: 270 pflogattach(1); 271 PF_RULES_WLOCK(); 272 pflog_packet_ptr = pflog_packet; 273 PF_RULES_WUNLOCK(); 274 break; 275 case MOD_UNLOAD: 276 PF_RULES_WLOCK(); 277 pflog_packet_ptr = NULL; 278 PF_RULES_WUNLOCK(); 279 if_clone_detach(pflog_cloner); 280 break; 281 default: 282 error = EINVAL; 283 break; 284 } 285 286 return error; 287 } 288 289 static moduledata_t pflog_mod = { pflogname, pflog_modevent, 0 }; 290 291 #define PFLOG_MODVER 1 292 293 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 294 MODULE_VERSION(pflog, PFLOG_MODVER); 295 MODULE_DEPEND(pflog, pf, PF_MODVER, PF_MODVER, PF_MODVER); 296