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 95 static const char pflogname[] = "pflog"; 96 97 static VNET_DEFINE(struct if_clone *, pflog_cloner); 98 #define V_pflog_cloner VNET(pflog_cloner) 99 100 VNET_DEFINE(struct ifnet *, pflogifs[PFLOGIFS_MAX]); /* for fast access */ 101 #define V_pflogifs VNET(pflogifs) 102 103 static void 104 pflogattach(int npflog __unused) 105 { 106 int i; 107 for (i = 0; i < PFLOGIFS_MAX; i++) 108 V_pflogifs[i] = NULL; 109 V_pflog_cloner = if_clone_simple(pflogname, pflog_clone_create, 110 pflog_clone_destroy, 1); 111 } 112 113 static int 114 pflog_clone_create(struct if_clone *ifc, int unit, caddr_t param) 115 { 116 struct ifnet *ifp; 117 118 if (unit >= PFLOGIFS_MAX) 119 return (EINVAL); 120 121 ifp = if_alloc(IFT_PFLOG); 122 if (ifp == NULL) { 123 return (ENOSPC); 124 } 125 if_initname(ifp, pflogname, unit); 126 ifp->if_mtu = PFLOGMTU; 127 ifp->if_ioctl = pflogioctl; 128 ifp->if_output = pflogoutput; 129 ifp->if_start = pflogstart; 130 ifp->if_snd.ifq_maxlen = ifqmaxlen; 131 ifp->if_hdrlen = PFLOG_HDRLEN; 132 if_attach(ifp); 133 134 bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN); 135 136 V_pflogifs[unit] = ifp; 137 138 return (0); 139 } 140 141 static void 142 pflog_clone_destroy(struct ifnet *ifp) 143 { 144 int i; 145 146 for (i = 0; i < PFLOGIFS_MAX; i++) 147 if (V_pflogifs[i] == ifp) 148 V_pflogifs[i] = NULL; 149 150 bpfdetach(ifp); 151 if_detach(ifp); 152 if_free(ifp); 153 } 154 155 /* 156 * Start output on the pflog interface. 157 */ 158 static void 159 pflogstart(struct ifnet *ifp) 160 { 161 struct mbuf *m; 162 163 for (;;) { 164 IF_LOCK(&ifp->if_snd); 165 _IF_DEQUEUE(&ifp->if_snd, m); 166 IF_UNLOCK(&ifp->if_snd); 167 168 if (m == NULL) 169 return; 170 else 171 m_freem(m); 172 } 173 } 174 175 static int 176 pflogoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 177 struct route *rt) 178 { 179 m_freem(m); 180 return (0); 181 } 182 183 /* ARGSUSED */ 184 static int 185 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 186 { 187 switch (cmd) { 188 case SIOCSIFFLAGS: 189 if (ifp->if_flags & IFF_UP) 190 ifp->if_drv_flags |= IFF_DRV_RUNNING; 191 else 192 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 193 break; 194 default: 195 return (ENOTTY); 196 } 197 198 return (0); 199 } 200 201 static int 202 pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir, 203 u_int8_t reason, struct pf_rule *rm, struct pf_rule *am, 204 struct pf_ruleset *ruleset, struct pf_pdesc *pd, int lookupsafe) 205 { 206 struct ifnet *ifn; 207 struct pfloghdr hdr; 208 209 if (kif == NULL || m == NULL || rm == NULL || pd == NULL) 210 return ( 1); 211 212 if ((ifn = V_pflogifs[rm->logif]) == NULL || !ifn->if_bpf) 213 return (0); 214 215 bzero(&hdr, sizeof(hdr)); 216 hdr.length = PFLOG_REAL_HDRLEN; 217 hdr.af = af; 218 hdr.action = rm->action; 219 hdr.reason = reason; 220 memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname)); 221 222 if (am == NULL) { 223 hdr.rulenr = htonl(rm->nr); 224 hdr.subrulenr = 1; 225 } else { 226 hdr.rulenr = htonl(am->nr); 227 hdr.subrulenr = htonl(rm->nr); 228 if (ruleset != NULL && ruleset->anchor != NULL) 229 strlcpy(hdr.ruleset, ruleset->anchor->name, 230 sizeof(hdr.ruleset)); 231 } 232 /* 233 * XXXGL: we avoid pf_socket_lookup() when we are holding 234 * state lock, since this leads to unsafe LOR. 235 * These conditions are very very rare, however. 236 */ 237 if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done && lookupsafe) 238 pd->lookup.done = pf_socket_lookup(dir, pd, m); 239 if (pd->lookup.done > 0) 240 hdr.uid = pd->lookup.uid; 241 else 242 hdr.uid = UID_MAX; 243 hdr.pid = NO_PID; 244 hdr.rule_uid = rm->cuid; 245 hdr.rule_pid = rm->cpid; 246 hdr.dir = dir; 247 248 #ifdef INET 249 if (af == AF_INET && dir == PF_OUT) { 250 struct ip *ip; 251 252 ip = mtod(m, struct ip *); 253 ip->ip_sum = 0; 254 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 255 } 256 #endif /* INET */ 257 258 if_inc_counter(ifn, IFCOUNTER_OPACKETS, 1); 259 if_inc_counter(ifn, IFCOUNTER_OBYTES, m->m_pkthdr.len); 260 BPF_MTAP2(ifn, &hdr, PFLOG_HDRLEN, m); 261 262 return (0); 263 } 264 265 static void 266 vnet_pflog_init(const void *unused __unused) 267 { 268 269 pflogattach(1); 270 } 271 VNET_SYSINIT(vnet_pflog_init, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY, 272 vnet_pflog_init, NULL); 273 274 static void 275 vnet_pflog_uninit(const void *unused __unused) 276 { 277 278 if_clone_detach(V_pflog_cloner); 279 } 280 /* 281 * Detach after pf is gone; otherwise we might touch pflog memory 282 * from within pf after freeing pflog. 283 */ 284 VNET_SYSUNINIT(vnet_pflog_uninit, SI_SUB_INIT_IF, SI_ORDER_SECOND, 285 vnet_pflog_uninit, NULL); 286 287 static int 288 pflog_modevent(module_t mod, int type, void *data) 289 { 290 int error = 0; 291 292 switch (type) { 293 case MOD_LOAD: 294 PF_RULES_WLOCK(); 295 pflog_packet_ptr = pflog_packet; 296 PF_RULES_WUNLOCK(); 297 break; 298 case MOD_UNLOAD: 299 PF_RULES_WLOCK(); 300 pflog_packet_ptr = NULL; 301 PF_RULES_WUNLOCK(); 302 break; 303 default: 304 error = EOPNOTSUPP; 305 break; 306 } 307 308 return error; 309 } 310 311 static moduledata_t pflog_mod = { pflogname, pflog_modevent, 0 }; 312 313 #define PFLOG_MODVER 1 314 315 /* Do not run before pf is initialized as we depend on its locks. */ 316 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY); 317 MODULE_VERSION(pflog, PFLOG_MODVER); 318 MODULE_DEPEND(pflog, pf, PF_MODVER, PF_MODVER, PF_MODVER); 319