sys/net/pf/if_pflog.c

   1 /*      $OpenBSD: if_pflog.c,v 1.27 2007/12/20 02:53:02 brad 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  * Copyright (c) 2010 The DragonFly Project.  All rights reserved.
  21  *
  22  * Permission to use, copy, and modify this software with or without fee
  23  * is hereby granted, provided that this entire notice is included in
  24  * all copies of any software which is or includes a copy or
  25  * modification of this software.
  26  * You may use this code under the GNU public license if you so wish. Please
  27  * contribute changes back to the authors under this freer than GPL license
  28  * so that we may further the use of strong encryption without limitations to
  29  * all.
  30  *
  31  * THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR
  32  * IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY
  33  * REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE
  34  * MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR
  35  * PURPOSE.
  36  */
  37
  38 #include "opt_inet.h"
  39 #include "opt_inet6.h"
  40
  41 #include <sys/param.h>
  42 #include <sys/systm.h>
  43 #include <sys/in_cksum.h>
  44 #include <sys/mbuf.h>
  45 #include <sys/proc.h>
  46 #include <sys/socket.h>
  47 #include <sys/kernel.h>
  48 #include <sys/malloc.h>
  49 #include <sys/module.h>
  50 #include <sys/sockio.h>
  51 #include <sys/thread2.h>
  52
  53 #include <net/if.h>
  54 #include <net/if_types.h>
  55 #include <net/ifq_var.h>
  56 #include <net/route.h>
  57 #include <net/bpf.h>
  58
  59 #ifdef  INET
  60 #include <netinet/in.h>
  61 #include <netinet/in_var.h>
  62 #include <netinet/in_systm.h>
  63 #include <netinet/ip.h>
  64 #endif
  65
  66 #ifdef INET6
  67 #ifndef INET
  68 #include <netinet/in.h>
  69 #endif
  70 #include <netinet6/nd6.h>
  71 #endif /* INET6 */
  72
  73 #include <net/pf/pfvar.h>
  74 #include <net/pf/if_pflog.h>
  75
  76 #define PFLOGNAME       "pflog"
  77
  78 #define PFLOGMTU        (32768 + MHLEN + MLEN)
  79
  80 #ifdef PFLOGDEBUG
  81 #define DPRINTF(x)    do { if (pflogdebug) kprintf x ; } while (0)
  82 #else
  83 #define DPRINTF(x)
  84 #endif
  85
  86 void    pflogattach(int);
  87 int     pflogoutput(struct ifnet *, struct mbuf *, struct sockaddr *,
  88                        struct rtentry *);
  89 int     pflogioctl(struct ifnet *, u_long, caddr_t, struct ucred *);
  90 void    pflogrtrequest(int, struct rtentry *, struct sockaddr *);
  91 void    pflogstart(struct ifnet *, struct ifaltq_subque *);
  92 int     pflog_clone_create(struct if_clone *, int, caddr_t);
  93 int     pflog_clone_destroy(struct ifnet *);
  94
  95 LIST_HEAD(, pflog_softc)        pflogif_list;
  96 struct if_clone pflog_cloner =
  97     IF_CLONE_INITIALIZER("pflog", pflog_clone_create, pflog_clone_destroy, 1, 1);
  98
  99 struct ifnet    *pflogifs[PFLOGIFS_MAX];        /* for fast access */
 100
 101 void
 102 pflogattach(int npflog)
 103 {
 104         int     i;
 105         LIST_INIT(&pflogif_list);
 106         for (i = 0; i < PFLOGIFS_MAX; i++)
 107                 pflogifs[i] = NULL;
 108         if_clone_attach(&pflog_cloner);
 109 }
 110
 111 int
 112 pflog_clone_create(struct if_clone *ifc, int unit, caddr_t param __unused)
 113 {
 114         struct ifnet *ifp;
 115         struct pflog_softc *pflogif;
 116
 117         lwkt_gettoken(&pf_token);
 118
 119         if (unit >= PFLOGIFS_MAX) {
 120                 lwkt_reltoken(&pf_token);
 121                 return (EINVAL);
 122         }
 123
 124         if ((pflogif = kmalloc(sizeof(*pflogif),
 125                 M_DEVBUF, M_WAITOK|M_ZERO)) == NULL) {
 126                 lwkt_reltoken(&pf_token);
 127                 return (ENOMEM);
 128         }
 129
 130         pflogif->sc_unit = unit;
 131         lwkt_reltoken(&pf_token);
 132         ifp = &pflogif->sc_if;
 133         ksnprintf(ifp->if_xname, sizeof ifp->if_xname, "pflog%d", unit);
 134         ifp->if_softc = pflogif;
 135         ifp->if_mtu = PFLOGMTU;
 136         ifp->if_ioctl = pflogioctl;
 137         ifp->if_output = pflogoutput;
 138         ifp->if_start = pflogstart;
 139         ifp->if_type = IFT_PFLOG;
 140         ifq_set_maxlen(&ifp->if_snd, ifqmaxlen);
 141         ifp->if_hdrlen = PFLOG_HDRLEN;
 142         if_attach(ifp, NULL);
 143
 144         bpfattach(&pflogif->sc_if, DLT_PFLOG, PFLOG_HDRLEN);
 145         lwkt_gettoken(&pf_token);
 146
 147         crit_enter();
 148         LIST_INSERT_HEAD(&pflogif_list, pflogif, sc_list);
 149         pflogifs[unit] = ifp;
 150         crit_exit();
 151
 152         lwkt_reltoken(&pf_token);
 153         return (0);
 154 }
 155
 156 int
 157 pflog_clone_destroy(struct ifnet *ifp)
 158 {
 159         struct pflog_softc      *pflogif = ifp->if_softc;
 160
 161         lwkt_gettoken(&pf_token);
 162
 163         crit_enter();
 164         pflogifs[pflogif->sc_unit] = NULL;
 165         LIST_REMOVE(pflogif, sc_list);
 166         crit_exit();
 167
 168         lwkt_reltoken(&pf_token);
 169 #if NBPFILTER > 0
 170         bpfdetach(ifp);
 171 #endif
 172         if_detach(ifp);
 173         lwkt_gettoken(&pf_token);
 174         kfree(pflogif, M_DEVBUF);
 175         lwkt_reltoken(&pf_token);
 176
 177         return 0;
 178 }
 179
 180 /*
 181  * Start output on the pflog interface.
 182  */
 183 void
 184 pflogstart(struct ifnet *ifp, struct ifaltq_subque *ifsq)
 185 {
 186         struct mbuf *m;
 187
 188         ASSERT_ALTQ_SQ_DEFAULT(ifp, ifsq);
 189         ASSERT_LWKT_TOKEN_HELD(&pf_token);
 190
 191         for (;;) {
 192                 m = ifsq_dequeue(ifsq);
 193                 if (m == NULL)
 194                         return;
 195                 else
 196                         m_freem(m);
 197         }
 198 }
 199
 200 int
 201 pflogoutput(struct ifnet *ifp, struct mbuf *m, struct sockaddr *dst,
 202         struct rtentry *rt)
 203 {
 204         m_freem(m);
 205         return (0);
 206 }
 207
 208 /* ARGSUSED */
 209 void
 210 pflogrtrequest(int cmd, struct rtentry *rt, struct sockaddr *sa)
 211 {
 212         if (rt)
 213                 rt->rt_rmx.rmx_mtu = PFLOGMTU;
 214 }
 215
 216 /* ARGSUSED */
 217 int
 218 pflogioctl(struct ifnet *ifp, u_long cmd, caddr_t data, struct ucred *cr)
 219 {
 220
 221         lwkt_gettoken(&pf_token);
 222
 223         switch (cmd) {
 224         case SIOCSIFFLAGS:
 225                 lwkt_reltoken(&pf_token);
 226                 if (ifp->if_flags & IFF_UP)
 227                         ifp->if_flags |= IFF_RUNNING;
 228                 else
 229                         ifp->if_flags &= ~IFF_RUNNING;
 230                 lwkt_gettoken(&pf_token);
 231                 break;
 232         default:
 233                 lwkt_reltoken(&pf_token);
 234                 return (EINVAL);
 235         }
 236
 237         lwkt_reltoken(&pf_token);
 238         return (0);
 239 }
 240
 241 int
 242 pflog_packet(struct pfi_kif *kif, struct mbuf *m, sa_family_t af, u_int8_t dir,
 243     u_int8_t reason, struct pf_rule *rm, struct pf_rule *am,
 244     struct pf_ruleset *ruleset, struct pf_pdesc *pd)
 245 {
 246         struct ifnet *ifn = NULL;
 247         struct pfloghdr hdr;
 248
 249         ASSERT_LWKT_TOKEN_HELD(&pf_token);
 250
 251         if (kif == NULL || m == NULL || rm == NULL)
 252                 return (-1);
 253
 254         if ((ifn = pflogifs[rm->logif]) == NULL || !ifn->if_bpf)
 255                 return (0);
 256
 257         bzero(&hdr, sizeof(hdr));
 258         hdr.length = PFLOG_REAL_HDRLEN;
 259         hdr.af = af;
 260         hdr.action = rm->action;
 261         hdr.reason = reason;
 262         memcpy(hdr.ifname, kif->pfik_name, sizeof(hdr.ifname));
 263
 264         if (am == NULL) {
 265                 hdr.rulenr = htonl(rm->nr);
 266                 hdr.subrulenr = -1;
 267         } else {
 268                 hdr.rulenr = htonl(am->nr);
 269                 hdr.subrulenr = htonl(rm->nr);
 270                 if (ruleset != NULL && ruleset->anchor != NULL)
 271                         strlcpy(hdr.ruleset, ruleset->anchor->name,
 272                             sizeof(hdr.ruleset));
 273         }
 274         if (rm->log & PF_LOG_SOCKET_LOOKUP && !pd->lookup.done)
 275                 pd->lookup.done = pf_socket_lookup(dir, pd);
 276         if (pd->lookup.done > 0) {
 277                 hdr.uid = pd->lookup.uid;
 278                 hdr.pid = pd->lookup.pid;
 279         } else {
 280                 hdr.uid = UID_MAX;
 281                 hdr.pid = NO_PID;
 282         }
 283         hdr.rule_uid = rm->cuid;
 284         hdr.rule_pid = rm->cpid;
 285         hdr.dir = dir;
 286
 287 #ifdef INET
 288         if (af == AF_INET) {
 289                 struct ip *ip;
 290                 ip = mtod(m, struct ip *);
 291                 ip->ip_len = htons(ip->ip_len);
 292                 ip->ip_off = htons(ip->ip_off);
 293
 294                 if (dir == PF_OUT) {
 295                         ip->ip_sum = 0;
 296                         ip->ip_sum = in_cksum(m, ip->ip_hl << 2);
 297                 }
 298         }
 299 #endif /* INET */
 300
 301         IFNET_STAT_INC(ifn, opackets, 1);
 302         IFNET_STAT_INC(ifn, obytes, m->m_pkthdr.len);
 303         if (ifn->if_bpf) {
 304                 bpf_gettoken();
 305                 if (ifn->if_bpf) {
 306                         bpf_mtap_hdr(ifn->if_bpf, (char *)&hdr, PFLOG_HDRLEN, m,
 307                             BPF_DIRECTION_OUT);
 308                 }
 309                 bpf_reltoken();
 310         }
 311
 312 #ifdef INET
 313         if (af == AF_INET) {
 314                 struct ip *ip = mtod(m, struct ip *);
 315
 316                 ip->ip_len = ntohs(ip->ip_len);
 317                 ip->ip_off = ntohs(ip->ip_off);
 318         }
 319 #endif /* INET */
 320
 321         return (0);
 322 }
 323
 324 static int
 325 pflog_modevent(module_t mod, int type, void *data)
 326 {
 327         int error = 0;
 328
 329         struct pflog_softc *pflogif, *tmp;
 330
 331         lwkt_gettoken(&pf_token);
 332
 333         switch (type) {
 334         case MOD_LOAD:
 335                 LIST_INIT(&pflogif_list);
 336                 lwkt_reltoken(&pf_token);
 337                 if_clone_attach(&pflog_cloner);
 338                 lwkt_gettoken(&pf_token);
 339                 break;
 340
 341         case MOD_UNLOAD:
 342                 lwkt_reltoken(&pf_token);
 343                 if_clone_detach(&pflog_cloner);
 344                 LIST_FOREACH_MUTABLE(pflogif, &pflogif_list, sc_list, tmp) {
 345                         pflog_clone_destroy(&pflogif->sc_if);
 346                 }
 347                 lwkt_gettoken(&pf_token);
 348                 break;
 349
 350         default:
 351                 error = EINVAL;
 352                 break;
 353         }
 354         lwkt_reltoken(&pf_token);
 355         return error;
 356 }
 357
 358 static moduledata_t pflog_mod = {
 359         "pflog",
 360         pflog_modevent,
 361         0
 362 };
 363
 364 DECLARE_MODULE(pflog, pflog_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
 365 MODULE_VERSION(pflog, PFLOG_MODVER);