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_private.h> 61 #include <net/if_types.h> 62 #include <net/vnet.h> 63 #include <net/pfvar.h> 64 65 #if defined(INET) || defined(INET6) 66 #include <netinet/in.h> 67 #endif 68 #ifdef INET 69 #include <netinet/in_var.h> 70 #include <netinet/ip.h> 71 #endif 72 73 #ifdef INET6 74 #include <netinet6/in6_var.h> 75 #include <netinet6/nd6.h> 76 #endif /* INET6 */ 77 78 #ifdef INET 79 #include <machine/in_cksum.h> 80 #endif /* INET */ 81 82 #define PFLOGMTU (32768 + MHLEN + MLEN) 83 84 #ifdef PFLOGDEBUG 85 #define DPRINTF(x) do { if (pflogdebug) printf x ; } while (0) 86 #else 87 #define DPRINTF(x) 88 #endif 89 90 static int pflogoutput(struct ifnet *, struct mbuf *, 91 const struct sockaddr *, struct route *); 92 static void pflogattach(int); 93 static int pflogioctl(struct ifnet *, u_long, caddr_t); 94 static void pflogstart(struct ifnet *); 95 static int pflog_clone_create(struct if_clone *, char *, size_t, 96 struct ifc_data *, struct ifnet **); 97 static int pflog_clone_destroy(struct if_clone *, struct ifnet *, uint32_t); 98 99 static const char pflogname[] = "pflog"; 100 101 VNET_DEFINE_STATIC(struct if_clone *, pflog_cloner); 102 #define V_pflog_cloner VNET(pflog_cloner) 103 104 VNET_DEFINE(struct ifnet *, pflogifs[PFLOGIFS_MAX]); /* for fast access */ 105 #define V_pflogifs VNET(pflogifs) 106 107 static void 108 pflogattach(int npflog __unused) 109 { 110 int i; 111 for (i = 0; i < PFLOGIFS_MAX; i++) 112 V_pflogifs[i] = NULL; 113 114 struct if_clone_addreq req = { 115 .create_f = pflog_clone_create, 116 .destroy_f = pflog_clone_destroy, 117 .flags = IFC_F_AUTOUNIT, 118 }; 119 V_pflog_cloner = ifc_attach_cloner(pflogname, &req); 120 struct ifc_data ifd = { .unit = 0 }; 121 ifc_create_ifp(pflogname, &ifd, NULL); 122 } 123 124 static int 125 pflog_clone_create(struct if_clone *ifc, char *name, size_t maxlen, 126 struct ifc_data *ifd, struct ifnet **ifpp) 127 { 128 struct ifnet *ifp; 129 130 if (ifd->unit >= PFLOGIFS_MAX) 131 return (EINVAL); 132 133 ifp = if_alloc(IFT_PFLOG); 134 if (ifp == NULL) { 135 return (ENOSPC); 136 } 137 if_initname(ifp, pflogname, ifd->unit); 138 ifp->if_mtu = PFLOGMTU; 139 ifp->if_ioctl = pflogioctl; 140 ifp->if_output = pflogoutput; 141 ifp->if_start = pflogstart; 142 ifp->if_snd.ifq_maxlen = ifqmaxlen; 143 ifp->if_hdrlen = PFLOG_HDRLEN; 144 if_attach(ifp); 145 146 bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN); 147 148 V_pflogifs[ifd->unit] = ifp; 149 *ifpp = ifp; 150 151 return (0); 152 } 153 154 static int 155 pflog_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags) 156 { 157 int i; 158 159 if (ifp->if_dunit == 0 && (flags & IFC_F_FORCE) == 0) 160 return (EINVAL); 161 162 for (i = 0; i < PFLOGIFS_MAX; i++) 163 if (V_pflogifs[i] == ifp) 164 V_pflogifs[i] = NULL; 165 166 bpfdetach(ifp); 167 if_detach(ifp); 168 if_free(ifp); 169 170 return (0); 171 } 172 173 /* 174 * Start output on the pflog interface. 175 */ 176 static void 177 pflogstart(struct ifnet *ifp) 178 { 179 struct mbuf *m; 180 181 for (;;) { 182 IF_LOCK(&ifp->if_snd); 183 _IF_DEQUEUE(&ifp->if_snd, m); 184 IF_UNLOCK(&ifp->if_snd); 185 186 if (m == NULL) 187 return; 188 else 189 m_freem(m); 190 } 191 } 192 193 static int 194 pflogoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 195 struct route *rt) 196 { 197 m_freem(m); 198 return (0); 199 } 200 201 /* ARGSUSED */ 202 static int 203 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 204 { 205 switch (cmd) { 206 case SIOCSIFFLAGS: 207 if (ifp->if_flags & IFF_UP) 208 ifp->if_drv_flags |= IFF_DRV_RUNNING; 209 else 210 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 211 break; 212 default: 213 return (ENOTTY); 214 } 215 216 return (0); 217 } 218 219 static int 220 pflog_packet(struct pfi_kkif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir, 221 u_int8_t reason, struct pf_krule *rm, struct pf_krule *am, 222 struct pf_kruleset *ruleset, struct pf_pdesc *pd, int lookupsafe) 223 { 224 struct ifnet *ifn; 225 struct pfloghdr hdr; 226 227 if (kif == NULL || m == NULL || rm == NULL || pd == NULL) 228 return ( 1); 229 230 if ((ifn = V_pflogifs[rm->logif]) == NULL || !ifn->if_bpf) 231 return (0); 232 233 bzero(&hdr, sizeof(hdr)); 234 hdr.length = PFLOG_REAL_HDRLEN; 235 hdr.af = af; 236 hdr.action = rm->action; 237 hdr.reason = reason; 238 memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname)); 239 240 if (am == NULL) { 241 hdr.rulenr = htonl(rm->nr); 242 hdr.subrulenr = -1; 243 } else { 244 hdr.rulenr = htonl(am->nr); 245 hdr.subrulenr = htonl(rm->nr); 246 if (ruleset != NULL && ruleset->anchor != NULL) 247 strlcpy(hdr.ruleset, ruleset->anchor->name, 248 sizeof(hdr.ruleset)); 249 } 250 hdr.ridentifier = htonl(rm->ridentifier); 251 /* 252 * XXXGL: we avoid pf_socket_lookup() when we are holding 253 * state lock, since this leads to unsafe LOR. 254 * These conditions are very very rare, however. 255 */ 256 if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done && lookupsafe) 257 pd->lookup.done = pf_socket_lookup(dir, pd, m); 258 if (pd->lookup.done > 0) 259 hdr.uid = pd->lookup.uid; 260 else 261 hdr.uid = UID_MAX; 262 hdr.pid = NO_PID; 263 hdr.rule_uid = rm->cuid; 264 hdr.rule_pid = rm->cpid; 265 hdr.dir = dir; 266 267 #ifdef INET 268 if (af == AF_INET && dir == PF_OUT) { 269 struct ip *ip; 270 271 ip = mtod(m, struct ip *); 272 ip->ip_sum = 0; 273 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 274 } 275 #endif /* INET */ 276 277 if_inc_counter(ifn, IFCOUNTER_OPACKETS, 1); 278 if_inc_counter(ifn, IFCOUNTER_OBYTES, m->m_pkthdr.len); 279 BPF_MTAP2(ifn, &hdr, PFLOG_HDRLEN, m); 280 281 return (0); 282 } 283 284 static void 285 vnet_pflog_init(const void *unused __unused) 286 { 287 288 pflogattach(1); 289 } 290 VNET_SYSINIT(vnet_pflog_init, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY, 291 vnet_pflog_init, NULL); 292 293 static void 294 vnet_pflog_uninit(const void *unused __unused) 295 { 296 297 ifc_detach_cloner(V_pflog_cloner); 298 } 299 /* 300 * Detach after pf is gone; otherwise we might touch pflog memory 301 * from within pf after freeing pflog. 302 */ 303 VNET_SYSUNINIT(vnet_pflog_uninit, SI_SUB_INIT_IF, SI_ORDER_SECOND, 304 vnet_pflog_uninit, NULL); 305 306 static int 307 pflog_modevent(module_t mod, int type, void *data) 308 { 309 int error = 0; 310 311 switch (type) { 312 case MOD_LOAD: 313 PF_RULES_WLOCK(); 314 pflog_packet_ptr = pflog_packet; 315 PF_RULES_WUNLOCK(); 316 break; 317 case MOD_UNLOAD: 318 PF_RULES_WLOCK(); 319 pflog_packet_ptr = NULL; 320 PF_RULES_WUNLOCK(); 321 break; 322 default: 323 error = EOPNOTSUPP; 324 break; 325 } 326 327 return error; 328 } 329 330 static moduledata_t pflog_mod = { pflogname, pflog_modevent, 0 }; 331 332 #define PFLOG_MODVER 1 333 334 /* Do not run before pf is initialized as we depend on its locks. */ 335 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY); 336 MODULE_VERSION(pflog, PFLOG_MODVER); 337 MODULE_DEPEND(pflog, pf, PF_MODVER, PF_MODVER, PF_MODVER); 338