1 /*- 2 * SPDX-License-Identifier: ISC 3 * 4 * The authors of this code are John Ioannidis (ji@tla.org), 5 * Angelos D. Keromytis (kermit@csd.uch.gr) and 6 * Niels Provos (provos@physnet.uni-hamburg.de). 7 * 8 * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 9 * in November 1995. 10 * 11 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, 12 * by Angelos D. Keromytis. 13 * 14 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis 15 * and Niels Provos. 16 * 17 * Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis 18 * and Niels Provos. 19 * Copyright (c) 2001, Angelos D. Keromytis, Niels Provos. 20 * 21 * Permission to use, copy, and modify this software with or without fee 22 * is hereby granted, provided that this entire notice is included in 23 * all copies of any software which is or includes a copy or 24 * modification of this software. 25 * You may use this code under the GNU public license if you so wish. Please 26 * contribute changes back to the authors under this freer than GPL license 27 * so that we may further the use of strong encryption without limitations to 28 * all. 29 * 30 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 31 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 32 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 33 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 34 * PURPOSE. 35 * 36 * $OpenBSD: if_pflog.c,v 1.26 2007/10/18 21:58:18 mpf Exp $ 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "opt_inet.h" 43 #include "opt_inet6.h" 44 #include "opt_bpf.h" 45 #include "opt_pf.h" 46 47 #include <sys/param.h> 48 #include <sys/kernel.h> 49 #include <sys/mbuf.h> 50 #include <sys/module.h> 51 #include <sys/proc.h> 52 #include <sys/socket.h> 53 #include <sys/sockio.h> 54 55 #include <net/bpf.h> 56 #include <net/if.h> 57 #include <net/if_var.h> 58 #include <net/if_clone.h> 59 #include <net/if_pflog.h> 60 #include <net/if_types.h> 61 #include <net/vnet.h> 62 #include <net/pfvar.h> 63 64 #if defined(INET) || defined(INET6) 65 #include <netinet/in.h> 66 #endif 67 #ifdef INET 68 #include <netinet/in_var.h> 69 #include <netinet/ip.h> 70 #endif 71 72 #ifdef INET6 73 #include <netinet6/in6_var.h> 74 #include <netinet6/nd6.h> 75 #endif /* INET6 */ 76 77 #ifdef INET 78 #include <machine/in_cksum.h> 79 #endif /* INET */ 80 81 #define PFLOGMTU (32768 + MHLEN + MLEN) 82 83 #ifdef PFLOGDEBUG 84 #define DPRINTF(x) do { if (pflogdebug) printf x ; } while (0) 85 #else 86 #define DPRINTF(x) 87 #endif 88 89 static int pflogoutput(struct ifnet *, struct mbuf *, 90 const struct sockaddr *, struct route *); 91 static void pflogattach(int); 92 static int pflogioctl(struct ifnet *, u_long, caddr_t); 93 static void pflogstart(struct ifnet *); 94 static int pflog_clone_create(struct if_clone *, int, caddr_t); 95 static void pflog_clone_destroy(struct ifnet *); 96 97 static const char pflogname[] = "pflog"; 98 99 VNET_DEFINE_STATIC(struct if_clone *, pflog_cloner); 100 #define V_pflog_cloner VNET(pflog_cloner) 101 102 VNET_DEFINE(struct ifnet *, pflogifs[PFLOGIFS_MAX]); /* for fast access */ 103 #define V_pflogifs VNET(pflogifs) 104 105 static void 106 pflogattach(int npflog __unused) 107 { 108 int i; 109 for (i = 0; i < PFLOGIFS_MAX; i++) 110 V_pflogifs[i] = NULL; 111 V_pflog_cloner = if_clone_simple(pflogname, pflog_clone_create, 112 pflog_clone_destroy, 1); 113 } 114 115 static int 116 pflog_clone_create(struct if_clone *ifc, int unit, caddr_t param) 117 { 118 struct ifnet *ifp; 119 120 if (unit >= PFLOGIFS_MAX) 121 return (EINVAL); 122 123 ifp = if_alloc(IFT_PFLOG); 124 if (ifp == NULL) { 125 return (ENOSPC); 126 } 127 if_initname(ifp, pflogname, unit); 128 ifp->if_mtu = PFLOGMTU; 129 ifp->if_ioctl = pflogioctl; 130 ifp->if_output = pflogoutput; 131 ifp->if_start = pflogstart; 132 ifp->if_snd.ifq_maxlen = ifqmaxlen; 133 ifp->if_hdrlen = PFLOG_HDRLEN; 134 if_attach(ifp); 135 136 bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN); 137 138 V_pflogifs[unit] = ifp; 139 140 return (0); 141 } 142 143 static void 144 pflog_clone_destroy(struct ifnet *ifp) 145 { 146 int i; 147 148 for (i = 0; i < PFLOGIFS_MAX; i++) 149 if (V_pflogifs[i] == ifp) 150 V_pflogifs[i] = NULL; 151 152 bpfdetach(ifp); 153 if_detach(ifp); 154 if_free(ifp); 155 } 156 157 /* 158 * Start output on the pflog interface. 159 */ 160 static void 161 pflogstart(struct ifnet *ifp) 162 { 163 struct mbuf *m; 164 165 for (;;) { 166 IF_LOCK(&ifp->if_snd); 167 _IF_DEQUEUE(&ifp->if_snd, m); 168 IF_UNLOCK(&ifp->if_snd); 169 170 if (m == NULL) 171 return; 172 else 173 m_freem(m); 174 } 175 } 176 177 static int 178 pflogoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 179 struct route *rt) 180 { 181 m_freem(m); 182 return (0); 183 } 184 185 /* ARGSUSED */ 186 static int 187 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 188 { 189 switch (cmd) { 190 case SIOCSIFFLAGS: 191 if (ifp->if_flags & IFF_UP) 192 ifp->if_drv_flags |= IFF_DRV_RUNNING; 193 else 194 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 195 break; 196 default: 197 return (ENOTTY); 198 } 199 200 return (0); 201 } 202 203 static int 204 pflog_packet(struct pfi_kkif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir, 205 u_int8_t reason, struct pf_krule *rm, struct pf_krule *am, 206 struct pf_kruleset *ruleset, struct pf_pdesc *pd, int lookupsafe) 207 { 208 struct ifnet *ifn; 209 struct pfloghdr hdr; 210 211 if (kif == NULL || m == NULL || rm == NULL || pd == NULL) 212 return ( 1); 213 214 if ((ifn = V_pflogifs[rm->logif]) == NULL || !ifn->if_bpf) 215 return (0); 216 217 bzero(&hdr, sizeof(hdr)); 218 hdr.length = PFLOG_REAL_HDRLEN; 219 hdr.af = af; 220 hdr.action = rm->action; 221 hdr.reason = reason; 222 memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname)); 223 224 if (am == NULL) { 225 hdr.rulenr = htonl(rm->nr); 226 hdr.subrulenr = -1; 227 } else { 228 hdr.rulenr = htonl(am->nr); 229 hdr.subrulenr = htonl(rm->nr); 230 if (ruleset != NULL && ruleset->anchor != NULL) 231 strlcpy(hdr.ruleset, ruleset->anchor->name, 232 sizeof(hdr.ruleset)); 233 } 234 hdr.ridentifier = htonl(rm->ridentifier); 235 /* 236 * XXXGL: we avoid pf_socket_lookup() when we are holding 237 * state lock, since this leads to unsafe LOR. 238 * These conditions are very very rare, however. 239 */ 240 if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done && lookupsafe) 241 pd->lookup.done = pf_socket_lookup(dir, pd, m); 242 if (pd->lookup.done > 0) 243 hdr.uid = pd->lookup.uid; 244 else 245 hdr.uid = UID_MAX; 246 hdr.pid = NO_PID; 247 hdr.rule_uid = rm->cuid; 248 hdr.rule_pid = rm->cpid; 249 hdr.dir = dir; 250 251 #ifdef INET 252 if (af == AF_INET && dir == PF_OUT) { 253 struct ip *ip; 254 255 ip = mtod(m, struct ip *); 256 ip->ip_sum = 0; 257 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 258 } 259 #endif /* INET */ 260 261 if_inc_counter(ifn, IFCOUNTER_OPACKETS, 1); 262 if_inc_counter(ifn, IFCOUNTER_OBYTES, m->m_pkthdr.len); 263 BPF_MTAP2(ifn, &hdr, PFLOG_HDRLEN, m); 264 265 return (0); 266 } 267 268 static void 269 vnet_pflog_init(const void *unused __unused) 270 { 271 272 pflogattach(1); 273 } 274 VNET_SYSINIT(vnet_pflog_init, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY, 275 vnet_pflog_init, NULL); 276 277 static void 278 vnet_pflog_uninit(const void *unused __unused) 279 { 280 281 if_clone_detach(V_pflog_cloner); 282 } 283 /* 284 * Detach after pf is gone; otherwise we might touch pflog memory 285 * from within pf after freeing pflog. 286 */ 287 VNET_SYSUNINIT(vnet_pflog_uninit, SI_SUB_INIT_IF, SI_ORDER_SECOND, 288 vnet_pflog_uninit, NULL); 289 290 static int 291 pflog_modevent(module_t mod, int type, void *data) 292 { 293 int error = 0; 294 295 switch (type) { 296 case MOD_LOAD: 297 PF_RULES_WLOCK(); 298 pflog_packet_ptr = pflog_packet; 299 PF_RULES_WUNLOCK(); 300 break; 301 case MOD_UNLOAD: 302 PF_RULES_WLOCK(); 303 pflog_packet_ptr = NULL; 304 PF_RULES_WUNLOCK(); 305 break; 306 default: 307 error = EOPNOTSUPP; 308 break; 309 } 310 311 return error; 312 } 313 314 static moduledata_t pflog_mod = { pflogname, pflog_modevent, 0 }; 315 316 #define PFLOG_MODVER 1 317 318 /* Do not run before pf is initialized as we depend on its locks. */ 319 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY); 320 MODULE_VERSION(pflog, PFLOG_MODVER); 321 MODULE_DEPEND(pflog, pf, PF_MODVER, PF_MODVER, PF_MODVER); 322