1 /* $OpenBSD: if_pflog.c,v 1.26 2007/10/18 21:58:18 mpf Exp $ */ 2 /* 3 * The authors of this code are John Ioannidis (ji@tla.org), 4 * Angelos D. Keromytis (kermit@csd.uch.gr) and 5 * Niels Provos (provos@physnet.uni-hamburg.de). 6 * 7 * This code was written by John Ioannidis for BSD/OS in Athens, Greece, 8 * in November 1995. 9 * 10 * Ported to OpenBSD and NetBSD, with additional transforms, in December 1996, 11 * by Angelos D. Keromytis. 12 * 13 * Additional transforms and features in 1997 and 1998 by Angelos D. Keromytis 14 * and Niels Provos. 15 * 16 * Copyright (C) 1995, 1996, 1997, 1998 by John Ioannidis, Angelos D. Keromytis 17 * and Niels Provos. 18 * Copyright (c) 2001, Angelos D. Keromytis, Niels Provos. 19 * 20 * Permission to use, copy, and modify this software with or without fee 21 * is hereby granted, provided that this entire notice is included in 22 * all copies of any software which is or includes a copy or 23 * modification of this software. 24 * You may use this code under the GNU public license if you so wish. Please 25 * contribute changes back to the authors under this freer than GPL license 26 * so that we may further the use of strong encryption without limitations to 27 * all. 28 * 29 * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 30 * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 31 * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 32 * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 33 * PURPOSE. 34 */ 35 36 #include <sys/cdefs.h> 37 __FBSDID("$FreeBSD$"); 38 39 #include "opt_inet.h" 40 #include "opt_inet6.h" 41 #include "opt_bpf.h" 42 #include "opt_pf.h" 43 44 #include <sys/param.h> 45 #include <sys/kernel.h> 46 #include <sys/mbuf.h> 47 #include <sys/module.h> 48 #include <sys/proc.h> 49 #include <sys/socket.h> 50 #include <sys/sockio.h> 51 52 #include <net/bpf.h> 53 #include <net/if.h> 54 #include <net/if_clone.h> 55 #include <net/if_pflog.h> 56 #include <net/if_types.h> 57 #include <net/pfvar.h> 58 59 #if defined(INET) || defined(INET6) 60 #include <netinet/in.h> 61 #endif 62 #ifdef INET 63 #include <netinet/in_var.h> 64 #include <netinet/ip.h> 65 #endif 66 67 #ifdef INET6 68 #include <netinet6/in6_var.h> 69 #include <netinet6/nd6.h> 70 #endif /* INET6 */ 71 72 #ifdef INET 73 #include <machine/in_cksum.h> 74 #endif /* INET */ 75 76 #define PFLOGMTU (32768 + MHLEN + MLEN) 77 78 #ifdef PFLOGDEBUG 79 #define DPRINTF(x) do { if (pflogdebug) printf x ; } while (0) 80 #else 81 #define DPRINTF(x) 82 #endif 83 84 static int pflogoutput(struct ifnet *, struct mbuf *, struct sockaddr *, 85 struct route *); 86 static void pflogattach(int); 87 static int pflogioctl(struct ifnet *, u_long, caddr_t); 88 static void pflogstart(struct ifnet *); 89 static int pflog_clone_create(struct if_clone *, int, caddr_t); 90 static void pflog_clone_destroy(struct ifnet *); 91 92 IFC_SIMPLE_DECLARE(pflog, 1); 93 94 struct ifnet *pflogifs[PFLOGIFS_MAX]; /* for fast access */ 95 96 static void 97 pflogattach(int npflog) 98 { 99 int i; 100 for (i = 0; i < PFLOGIFS_MAX; i++) 101 pflogifs[i] = NULL; 102 if_clone_attach(&pflog_cloner); 103 } 104 105 static int 106 pflog_clone_create(struct if_clone *ifc, int unit, caddr_t param) 107 { 108 struct ifnet *ifp; 109 110 if (unit >= PFLOGIFS_MAX) 111 return (EINVAL); 112 113 ifp = if_alloc(IFT_PFLOG); 114 if (ifp == NULL) { 115 return (ENOSPC); 116 } 117 if_initname(ifp, ifc->ifc_name, unit); 118 ifp->if_mtu = PFLOGMTU; 119 ifp->if_ioctl = pflogioctl; 120 ifp->if_output = pflogoutput; 121 ifp->if_start = pflogstart; 122 ifp->if_snd.ifq_maxlen = ifqmaxlen; 123 ifp->if_hdrlen = PFLOG_HDRLEN; 124 if_attach(ifp); 125 126 bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN); 127 128 pflogifs[unit] = ifp; 129 130 return (0); 131 } 132 133 static void 134 pflog_clone_destroy(struct ifnet *ifp) 135 { 136 int i; 137 138 for (i = 0; i < PFLOGIFS_MAX; i++) 139 if (pflogifs[i] == ifp) 140 pflogifs[i] = NULL; 141 142 bpfdetach(ifp); 143 if_detach(ifp); 144 if_free(ifp); 145 } 146 147 /* 148 * Start output on the pflog interface. 149 */ 150 static void 151 pflogstart(struct ifnet *ifp) 152 { 153 struct mbuf *m; 154 155 for (;;) { 156 IF_LOCK(&ifp->if_snd); 157 _IF_DROP(&ifp->if_snd); 158 _IF_DEQUEUE(&ifp->if_snd, m); 159 IF_UNLOCK(&ifp->if_snd); 160 161 if (m == NULL) 162 return; 163 else 164 m_freem(m); 165 } 166 } 167 168 static int 169 pflogoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 170 struct route *rt) 171 { 172 m_freem(m); 173 return (0); 174 } 175 176 /* ARGSUSED */ 177 static int 178 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 179 { 180 switch (cmd) { 181 case SIOCSIFFLAGS: 182 if (ifp->if_flags & IFF_UP) 183 ifp->if_drv_flags |= IFF_DRV_RUNNING; 184 else 185 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 186 break; 187 default: 188 return (ENOTTY); 189 } 190 191 return (0); 192 } 193 194 static int 195 pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir, 196 u_int8_t reason, struct pf_rule *rm, struct pf_rule *am, 197 struct pf_ruleset *ruleset, struct pf_pdesc *pd, int lookupsafe) 198 { 199 struct ifnet *ifn; 200 struct pfloghdr hdr; 201 202 if (kif == NULL || m == NULL || rm == NULL || pd == NULL) 203 return ( 1); 204 205 if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf) 206 return (0); 207 208 bzero(&hdr, sizeof(hdr)); 209 hdr.length = PFLOG_REAL_HDRLEN; 210 hdr.af = af; 211 hdr.action = rm->action; 212 hdr.reason = reason; 213 memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname)); 214 215 if (am == NULL) { 216 hdr.rulenr = htonl(rm->nr); 217 hdr.subrulenr = 1; 218 } else { 219 hdr.rulenr = htonl(am->nr); 220 hdr.subrulenr = htonl(rm->nr); 221 if (ruleset != NULL && ruleset->anchor != NULL) 222 strlcpy(hdr.ruleset, ruleset->anchor->name, 223 sizeof(hdr.ruleset)); 224 } 225 /* 226 * XXXGL: we avoid pf_socket_lookup() when we are holding 227 * state lock, since this leads to unsafe LOR. 228 * These conditions are very very rare, however. 229 */ 230 if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done && lookupsafe) 231 pd->lookup.done = pf_socket_lookup(dir, pd, m); 232 if (pd->lookup.done > 0) 233 hdr.uid = pd->lookup.uid; 234 else 235 hdr.uid = UID_MAX; 236 hdr.pid = NO_PID; 237 hdr.rule_uid = rm->cuid; 238 hdr.rule_pid = rm->cpid; 239 hdr.dir = dir; 240 241 #ifdef INET 242 if (af == AF_INET && dir == PF_OUT) { 243 struct ip *ip; 244 245 ip = mtod(m, struct ip *); 246 ip->ip_sum = 0; 247 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 248 } 249 #endif /* INET */ 250 251 ifn->if_opackets++; 252 ifn->if_obytes += m->m_pkthdr.len; 253 BPF_MTAP2(ifn, &hdr, PFLOG_HDRLEN, m); 254 255 return (0); 256 } 257 258 static int 259 pflog_modevent(module_t mod, int type, void *data) 260 { 261 int error = 0; 262 263 switch (type) { 264 case MOD_LOAD: 265 pflogattach(1); 266 PF_RULES_WLOCK(); 267 pflog_packet_ptr = pflog_packet; 268 PF_RULES_WUNLOCK(); 269 break; 270 case MOD_UNLOAD: 271 PF_RULES_WLOCK(); 272 pflog_packet_ptr = NULL; 273 PF_RULES_WUNLOCK(); 274 if_clone_detach(&pflog_cloner); 275 break; 276 default: 277 error = EINVAL; 278 break; 279 } 280 281 return error; 282 } 283 284 static moduledata_t pflog_mod = { "pflog", pflog_modevent, NULL }; 285 286 #define PFLOG_MODVER 1 287 288 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 289 MODULE_VERSION(pflog, PFLOG_MODVER); 290 MODULE_DEPEND(pflog, pf, PF_MODVER, PF_MODVER, PF_MODVER); 291