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 static struct if_clone *pflog_cloner; 95 96 static const char pflogname[] = "pflog"; 97 98 struct ifnet *pflogifs[PFLOGIFS_MAX]; /* for fast access */ 99 100 static void 101 pflogattach(int npflog) 102 { 103 int i; 104 for (i = 0; i < PFLOGIFS_MAX; i++) 105 pflogifs[i] = NULL; 106 pflog_cloner = if_clone_simple(pflogname, pflog_clone_create, 107 pflog_clone_destroy, 1); 108 } 109 110 static int 111 pflog_clone_create(struct if_clone *ifc, int unit, caddr_t param) 112 { 113 struct ifnet *ifp; 114 115 if (unit >= PFLOGIFS_MAX) 116 return (EINVAL); 117 118 ifp = if_alloc(IFT_PFLOG); 119 if (ifp == NULL) { 120 return (ENOSPC); 121 } 122 if_initname(ifp, pflogname, unit); 123 ifp->if_mtu = PFLOGMTU; 124 ifp->if_ioctl = pflogioctl; 125 ifp->if_output = pflogoutput; 126 ifp->if_start = pflogstart; 127 ifp->if_snd.ifq_maxlen = ifqmaxlen; 128 ifp->if_hdrlen = PFLOG_HDRLEN; 129 if_attach(ifp); 130 131 bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN); 132 133 pflogifs[unit] = ifp; 134 135 return (0); 136 } 137 138 static void 139 pflog_clone_destroy(struct ifnet *ifp) 140 { 141 int i; 142 143 for (i = 0; i < PFLOGIFS_MAX; i++) 144 if (pflogifs[i] == ifp) 145 pflogifs[i] = NULL; 146 147 bpfdetach(ifp); 148 if_detach(ifp); 149 if_free(ifp); 150 } 151 152 /* 153 * Start output on the pflog interface. 154 */ 155 static void 156 pflogstart(struct ifnet *ifp) 157 { 158 struct mbuf *m; 159 160 for (;;) { 161 IF_LOCK(&ifp->if_snd); 162 _IF_DEQUEUE(&ifp->if_snd, m); 163 IF_UNLOCK(&ifp->if_snd); 164 165 if (m == NULL) 166 return; 167 else 168 m_freem(m); 169 } 170 } 171 172 static int 173 pflogoutput(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 174 struct route *rt) 175 { 176 m_freem(m); 177 return (0); 178 } 179 180 /* ARGSUSED */ 181 static int 182 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 183 { 184 switch (cmd) { 185 case SIOCSIFFLAGS: 186 if (ifp->if_flags & IFF_UP) 187 ifp->if_drv_flags |= IFF_DRV_RUNNING; 188 else 189 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 190 break; 191 default: 192 return (ENOTTY); 193 } 194 195 return (0); 196 } 197 198 static int 199 pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir, 200 u_int8_t reason, struct pf_rule *rm, struct pf_rule *am, 201 struct pf_ruleset *ruleset, struct pf_pdesc *pd, int lookupsafe) 202 { 203 struct ifnet *ifn; 204 struct pfloghdr hdr; 205 206 if (kif == NULL || m == NULL || rm == NULL || pd == NULL) 207 return ( 1); 208 209 if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf) 210 return (0); 211 212 bzero(&hdr, sizeof(hdr)); 213 hdr.length = PFLOG_REAL_HDRLEN; 214 hdr.af = af; 215 hdr.action = rm->action; 216 hdr.reason = reason; 217 memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname)); 218 219 if (am == NULL) { 220 hdr.rulenr = htonl(rm->nr); 221 hdr.subrulenr = 1; 222 } else { 223 hdr.rulenr = htonl(am->nr); 224 hdr.subrulenr = htonl(rm->nr); 225 if (ruleset != NULL && ruleset->anchor != NULL) 226 strlcpy(hdr.ruleset, ruleset->anchor->name, 227 sizeof(hdr.ruleset)); 228 } 229 /* 230 * XXXGL: we avoid pf_socket_lookup() when we are holding 231 * state lock, since this leads to unsafe LOR. 232 * These conditions are very very rare, however. 233 */ 234 if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done && lookupsafe) 235 pd->lookup.done = pf_socket_lookup(dir, pd, m); 236 if (pd->lookup.done > 0) 237 hdr.uid = pd->lookup.uid; 238 else 239 hdr.uid = UID_MAX; 240 hdr.pid = NO_PID; 241 hdr.rule_uid = rm->cuid; 242 hdr.rule_pid = rm->cpid; 243 hdr.dir = dir; 244 245 #ifdef INET 246 if (af == AF_INET && dir == PF_OUT) { 247 struct ip *ip; 248 249 ip = mtod(m, struct ip *); 250 ip->ip_sum = 0; 251 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 252 } 253 #endif /* INET */ 254 255 if_inc_counter(ifn, IFCOUNTER_OPACKETS, 1); 256 if_inc_counter(ifn, IFCOUNTER_OBYTES, m->m_pkthdr.len); 257 BPF_MTAP2(ifn, &hdr, PFLOG_HDRLEN, m); 258 259 return (0); 260 } 261 262 static int 263 pflog_modevent(module_t mod, int type, void *data) 264 { 265 int error = 0; 266 267 switch (type) { 268 case MOD_LOAD: 269 pflogattach(1); 270 PF_RULES_WLOCK(); 271 pflog_packet_ptr = pflog_packet; 272 PF_RULES_WUNLOCK(); 273 break; 274 case MOD_UNLOAD: 275 PF_RULES_WLOCK(); 276 pflog_packet_ptr = NULL; 277 PF_RULES_WUNLOCK(); 278 if_clone_detach(pflog_cloner); 279 break; 280 default: 281 error = EINVAL; 282 break; 283 } 284 285 return error; 286 } 287 288 static moduledata_t pflog_mod = { pflogname, pflog_modevent, 0 }; 289 290 #define PFLOG_MODVER 1 291 292 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 293 MODULE_VERSION(pflog, PFLOG_MODVER); 294 MODULE_DEPEND(pflog, pf, PF_MODVER, PF_MODVER, PF_MODVER); 295