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 static struct if_clone *pflog_cloner; 92 93 static const char pflogname[] = "pflog"; 94 95 struct ifnet *pflogifs[PFLOGIFS_MAX]; /* for fast access */ 96 97 static void 98 pflogattach(int npflog) 99 { 100 int i; 101 for (i = 0; i < PFLOGIFS_MAX; i++) 102 pflogifs[i] = NULL; 103 pflog_cloner = if_clone_simple(pflogname, pflog_clone_create, 104 pflog_clone_destroy, 1); 105 } 106 107 static int 108 pflog_clone_create(struct if_clone *ifc, int unit, caddr_t param) 109 { 110 struct ifnet *ifp; 111 112 if (unit >= PFLOGIFS_MAX) 113 return (EINVAL); 114 115 ifp = if_alloc(IFT_PFLOG); 116 if (ifp == NULL) { 117 return (ENOSPC); 118 } 119 if_initname(ifp, pflogname, unit); 120 ifp->if_mtu = PFLOGMTU; 121 ifp->if_ioctl = pflogioctl; 122 ifp->if_output = pflogoutput; 123 ifp->if_start = pflogstart; 124 ifp->if_snd.ifq_maxlen = ifqmaxlen; 125 ifp->if_hdrlen = PFLOG_HDRLEN; 126 if_attach(ifp); 127 128 bpfattach(ifp, DLT_PFLOG, PFLOG_HDRLEN); 129 130 pflogifs[unit] = ifp; 131 132 return (0); 133 } 134 135 static void 136 pflog_clone_destroy(struct ifnet *ifp) 137 { 138 int i; 139 140 for (i = 0; i < PFLOGIFS_MAX; i++) 141 if (pflogifs[i] == ifp) 142 pflogifs[i] = NULL; 143 144 bpfdetach(ifp); 145 if_detach(ifp); 146 if_free(ifp); 147 } 148 149 /* 150 * Start output on the pflog interface. 151 */ 152 static void 153 pflogstart(struct ifnet *ifp) 154 { 155 struct mbuf *m; 156 157 for (;;) { 158 IF_LOCK(&ifp->if_snd); 159 _IF_DROP(&ifp->if_snd); 160 _IF_DEQUEUE(&ifp->if_snd, m); 161 IF_UNLOCK(&ifp->if_snd); 162 163 if (m == NULL) 164 return; 165 else 166 m_freem(m); 167 } 168 } 169 170 static int 171 pflogoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst, 172 struct route *rt) 173 { 174 m_freem(m); 175 return (0); 176 } 177 178 /* ARGSUSED */ 179 static int 180 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 181 { 182 switch (cmd) { 183 case SIOCSIFFLAGS: 184 if (ifp->if_flags & IFF_UP) 185 ifp->if_drv_flags |= IFF_DRV_RUNNING; 186 else 187 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 188 break; 189 default: 190 return (ENOTTY); 191 } 192 193 return (0); 194 } 195 196 static int 197 pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir, 198 u_int8_t reason, struct pf_rule *rm, struct pf_rule *am, 199 struct pf_ruleset *ruleset, struct pf_pdesc *pd, int lookupsafe) 200 { 201 struct ifnet *ifn; 202 struct pfloghdr hdr; 203 204 if (kif == NULL || m == NULL || rm == NULL || pd == NULL) 205 return ( 1); 206 207 if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf) 208 return (0); 209 210 bzero(&hdr, sizeof(hdr)); 211 hdr.length = PFLOG_REAL_HDRLEN; 212 hdr.af = af; 213 hdr.action = rm->action; 214 hdr.reason = reason; 215 memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname)); 216 217 if (am == NULL) { 218 hdr.rulenr = htonl(rm->nr); 219 hdr.subrulenr = 1; 220 } else { 221 hdr.rulenr = htonl(am->nr); 222 hdr.subrulenr = htonl(rm->nr); 223 if (ruleset != NULL && ruleset->anchor != NULL) 224 strlcpy(hdr.ruleset, ruleset->anchor->name, 225 sizeof(hdr.ruleset)); 226 } 227 /* 228 * XXXGL: we avoid pf_socket_lookup() when we are holding 229 * state lock, since this leads to unsafe LOR. 230 * These conditions are very very rare, however. 231 */ 232 if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done && lookupsafe) 233 pd->lookup.done = pf_socket_lookup(dir, pd, m); 234 if (pd->lookup.done > 0) 235 hdr.uid = pd->lookup.uid; 236 else 237 hdr.uid = UID_MAX; 238 hdr.pid = NO_PID; 239 hdr.rule_uid = rm->cuid; 240 hdr.rule_pid = rm->cpid; 241 hdr.dir = dir; 242 243 #ifdef INET 244 if (af == AF_INET && dir == PF_OUT) { 245 struct ip *ip; 246 247 ip = mtod(m, struct ip *); 248 ip->ip_sum = 0; 249 ip->ip_sum = in_cksum(m, ip->ip_hl << 2); 250 } 251 #endif /* INET */ 252 253 ifn->if_opackets++; 254 ifn->if_obytes += m->m_pkthdr.len; 255 BPF_MTAP2(ifn, &hdr, PFLOG_HDRLEN, m); 256 257 return (0); 258 } 259 260 static int 261 pflog_modevent(module_t mod, int type, void *data) 262 { 263 int error = 0; 264 265 switch (type) { 266 case MOD_LOAD: 267 pflogattach(1); 268 PF_RULES_WLOCK(); 269 pflog_packet_ptr = pflog_packet; 270 PF_RULES_WUNLOCK(); 271 break; 272 case MOD_UNLOAD: 273 PF_RULES_WLOCK(); 274 pflog_packet_ptr = NULL; 275 PF_RULES_WUNLOCK(); 276 if_clone_detach(pflog_cloner); 277 break; 278 default: 279 error = EINVAL; 280 break; 281 } 282 283 return error; 284 } 285 286 static moduledata_t pflog_mod = { pflogname, pflog_modevent, 0 }; 287 288 #define PFLOG_MODVER 1 289 290 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 291 MODULE_VERSION(pflog, PFLOG_MODVER); 292 MODULE_DEPEND(pflog, pf, PF_MODVER, PF_MODVER, PF_MODVER); 293