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