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 #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_private.h> 59 #include <net/if_types.h> 60 #include <net/vnet.h> 61 #include <net/pfvar.h> 62 63 #if defined(INET) || defined(INET6) 64 #include <netinet/in.h> 65 #endif 66 #ifdef INET 67 #include <netinet/in_var.h> 68 #include <netinet/ip.h> 69 #endif 70 71 #ifdef INET6 72 #include <netinet6/in6_var.h> 73 #include <netinet6/nd6.h> 74 #endif /* INET6 */ 75 76 #ifdef INET 77 #include <machine/in_cksum.h> 78 #endif /* INET */ 79 80 #define PFLOGMTU (32768 + MHLEN + MLEN) 81 82 #ifdef PFLOGDEBUG 83 #define DPRINTF(x) do { if (pflogdebug) printf x ; } while (0) 84 #else 85 #define DPRINTF(x) 86 #endif 87 88 static int pflogoutput(struct ifnet *, struct mbuf *, 89 const struct sockaddr *, struct route *); 90 static void pflogattach(int); 91 static int pflogioctl(struct ifnet *, u_long, caddr_t); 92 static void pflogstart(struct ifnet *); 93 static int pflog_clone_create(struct if_clone *, char *, size_t, 94 struct ifc_data *, struct ifnet **); 95 static int pflog_clone_destroy(struct if_clone *, struct ifnet *, uint32_t); 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; 109 110 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 | IFC_F_LIMITUNIT, 117 .maxunit = PFLOGIFS_MAX - 1, 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 MPASS(ifd->unit < PFLOGIFS_MAX); 131 132 ifp = if_alloc(IFT_PFLOG); 133 if_initname(ifp, pflogname, ifd->unit); 134 ifp->if_mtu = PFLOGMTU; 135 ifp->if_ioctl = pflogioctl; 136 ifp->if_output = pflogoutput; 137 ifp->if_start = pflogstart; 138 ifp->if_snd.ifq_maxlen = ifqmaxlen; 139 ifp->if_hdrlen = PFLOG_HDRLEN; 140 if_attach(ifp); 141 142 bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN); 143 144 V_pflogifs[ifd->unit] = ifp; 145 *ifpp = ifp; 146 147 return (0); 148 } 149 150 static int 151 pflog_clone_destroy(struct if_clone *ifc, struct ifnet *ifp, uint32_t flags) 152 { 153 int i; 154 155 if (ifp->if_dunit == 0 && (flags & IFC_F_FORCE) == 0) 156 return (EINVAL); 157 158 for (i = 0; i < PFLOGIFS_MAX; i++) 159 if (V_pflogifs[i] == ifp) 160 V_pflogifs[i] = NULL; 161 162 bpfdetach(ifp); 163 if_detach(ifp); 164 if_free(ifp); 165 166 return (0); 167 } 168 169 /* 170 * Start output on the pflog interface. 171 */ 172 static void 173 pflogstart(struct ifnet *ifp) 174 { 175 struct mbuf *m; 176 177 for (;;) { 178 IF_LOCK(&ifp->if_snd); 179 _IF_DEQUEUE(&ifp->if_snd, m); 180 IF_UNLOCK(&ifp->if_snd); 181 182 if (m == NULL) 183 return; 184 else 185 m_freem(m); 186 } 187 } 188 189 static int 190 pflogoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 191 struct route *rt) 192 { 193 m_freem(m); 194 return (0); 195 } 196 197 /* ARGSUSED */ 198 static int 199 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 200 { 201 switch (cmd) { 202 case SIOCSIFFLAGS: 203 if (ifp->if_flags & IFF_UP) 204 ifp->if_drv_flags |= IFF_DRV_RUNNING; 205 else 206 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 207 break; 208 default: 209 return (ENOTTY); 210 } 211 212 return (0); 213 } 214 215 static int 216 pflog_packet(uint8_t action, u_int8_t reason, 217 struct pf_krule *rm, struct pf_krule *am, 218 struct pf_kruleset *ruleset, struct pf_pdesc *pd, int lookupsafe) 219 { 220 struct ifnet *ifn; 221 struct pfloghdr hdr; 222 223 if (rm == NULL || pd == NULL) 224 return (1); 225 226 ifn = V_pflogifs[rm->logif]; 227 if (ifn == NULL || !bpf_peers_present(ifn->if_bpf)) 228 return (0); 229 230 bzero(&hdr, sizeof(hdr)); 231 hdr.length = PFLOG_REAL_HDRLEN; 232 hdr.af = pd->af; 233 hdr.action = action; 234 hdr.reason = reason; 235 memcpy(hdr.ifname, pd->kif->pfik_name, sizeof(hdr.ifname)); 236 237 if (am == NULL) { 238 hdr.rulenr = htonl(rm->nr); 239 hdr.subrulenr = -1; 240 } else { 241 hdr.rulenr = htonl(am->nr); 242 hdr.subrulenr = htonl(rm->nr); 243 if (ruleset != NULL && ruleset->anchor != NULL) 244 strlcpy(hdr.ruleset, ruleset->anchor->name, 245 sizeof(hdr.ruleset)); 246 } 247 hdr.ridentifier = htonl(rm->ridentifier); 248 /* 249 * XXXGL: we avoid pf_socket_lookup() when we are holding 250 * state lock, since this leads to unsafe LOR. 251 * These conditions are very very rare, however. 252 */ 253 if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done && lookupsafe) 254 pd->lookup.done = pf_socket_lookup(pd); 255 if (pd->lookup.done > 0) 256 hdr.uid = pd->lookup.uid; 257 else 258 hdr.uid = UID_MAX; 259 hdr.pid = NO_PID; 260 hdr.rule_uid = rm->cuid; 261 hdr.rule_pid = rm->cpid; 262 hdr.dir = pd->dir; 263 264 #ifdef INET 265 if (pd->af == AF_INET && pd->dir == PF_OUT) { 266 struct ip *ip; 267 268 ip = mtod(pd->m, struct ip *); 269 ip->ip_sum = 0; 270 ip->ip_sum = in_cksum(pd->m, ip->ip_hl << 2); 271 } 272 #endif /* INET */ 273 274 if_inc_counter(ifn, IFCOUNTER_OPACKETS, 1); 275 if_inc_counter(ifn, IFCOUNTER_OBYTES, pd->m->m_pkthdr.len); 276 bpf_mtap2(ifn->if_bpf, &hdr, PFLOG_HDRLEN, pd->m); 277 278 return (0); 279 } 280 281 static void 282 vnet_pflog_init(const void *unused __unused) 283 { 284 285 pflogattach(1); 286 } 287 VNET_SYSINIT(vnet_pflog_init, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY, 288 vnet_pflog_init, NULL); 289 290 static void 291 vnet_pflog_uninit(const void *unused __unused) 292 { 293 294 ifc_detach_cloner(V_pflog_cloner); 295 } 296 /* 297 * Detach after pf is gone; otherwise we might touch pflog memory 298 * from within pf after freeing pflog. 299 */ 300 VNET_SYSUNINIT(vnet_pflog_uninit, SI_SUB_INIT_IF, SI_ORDER_SECOND, 301 vnet_pflog_uninit, NULL); 302 303 static int 304 pflog_modevent(module_t mod, int type, void *data) 305 { 306 int error = 0; 307 308 switch (type) { 309 case MOD_LOAD: 310 PF_RULES_WLOCK(); 311 pflog_packet_ptr = pflog_packet; 312 PF_RULES_WUNLOCK(); 313 break; 314 case MOD_UNLOAD: 315 PF_RULES_WLOCK(); 316 pflog_packet_ptr = NULL; 317 PF_RULES_WUNLOCK(); 318 break; 319 default: 320 error = EOPNOTSUPP; 321 break; 322 } 323 324 return error; 325 } 326 327 static moduledata_t pflog_mod = { pflogname, pflog_modevent, 0 }; 328 329 #define PFLOG_MODVER 1 330 331 /* Do not run before pf is initialized as we depend on its locks. */ 332 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PROTO_FIREWALL, SI_ORDER_ANY); 333 MODULE_VERSION(pflog, PFLOG_MODVER); 334 MODULE_DEPEND(pflog, pf, PF_MODVER, PF_MODVER, PF_MODVER); 335