Current Path : /sys/net/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
Current File : //sys/net/pfil.c |
/* $FreeBSD: release/9.1.0/sys/net/pfil.c 198233 2009-10-19 15:19:14Z rwatson $ */ /* $NetBSD: pfil.c,v 1.20 2001/11/12 23:49:46 lukem Exp $ */ /*- * Copyright (c) 1996 Matthew R. Green * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. The name of the author may not be used to endorse or promote products * derived from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include <sys/param.h> #include <sys/kernel.h> #include <sys/errno.h> #include <sys/lock.h> #include <sys/malloc.h> #include <sys/rmlock.h> #include <sys/socket.h> #include <sys/socketvar.h> #include <sys/systm.h> #include <sys/condvar.h> #include <sys/lock.h> #include <sys/mutex.h> #include <sys/proc.h> #include <sys/queue.h> #include <net/if.h> #include <net/pfil.h> static struct mtx pfil_global_lock; MTX_SYSINIT(pfil_heads_lock, &pfil_global_lock, "pfil_head_list lock", MTX_DEF); static int pfil_list_add(pfil_list_t *, struct packet_filter_hook *, int); static int pfil_list_remove(pfil_list_t *, int (*)(void *, struct mbuf **, struct ifnet *, int, struct inpcb *), void *); LIST_HEAD(pfilheadhead, pfil_head); VNET_DEFINE(struct pfilheadhead, pfil_head_list); #define V_pfil_head_list VNET(pfil_head_list) /* * pfil_run_hooks() runs the specified packet filter hooks. */ int pfil_run_hooks(struct pfil_head *ph, struct mbuf **mp, struct ifnet *ifp, int dir, struct inpcb *inp) { struct rm_priotracker rmpt; struct packet_filter_hook *pfh; struct mbuf *m = *mp; int rv = 0; PFIL_RLOCK(ph, &rmpt); KASSERT(ph->ph_nhooks >= 0, ("Pfil hook count dropped < 0")); for (pfh = pfil_hook_get(dir, ph); pfh != NULL; pfh = TAILQ_NEXT(pfh, pfil_link)) { if (pfh->pfil_func != NULL) { rv = (*pfh->pfil_func)(pfh->pfil_arg, &m, ifp, dir, inp); if (rv != 0 || m == NULL) break; } } PFIL_RUNLOCK(ph, &rmpt); *mp = m; return (rv); } /* * pfil_head_register() registers a pfil_head with the packet filter hook * mechanism. */ int pfil_head_register(struct pfil_head *ph) { struct pfil_head *lph; PFIL_LIST_LOCK(); LIST_FOREACH(lph, &V_pfil_head_list, ph_list) { if (ph->ph_type == lph->ph_type && ph->ph_un.phu_val == lph->ph_un.phu_val) { PFIL_LIST_UNLOCK(); return (EEXIST); } } PFIL_LOCK_INIT(ph); ph->ph_nhooks = 0; TAILQ_INIT(&ph->ph_in); TAILQ_INIT(&ph->ph_out); LIST_INSERT_HEAD(&V_pfil_head_list, ph, ph_list); PFIL_LIST_UNLOCK(); return (0); } /* * pfil_head_unregister() removes a pfil_head from the packet filter hook * mechanism. The producer of the hook promises that all outstanding * invocations of the hook have completed before it unregisters the hook. */ int pfil_head_unregister(struct pfil_head *ph) { struct packet_filter_hook *pfh, *pfnext; PFIL_LIST_LOCK(); LIST_REMOVE(ph, ph_list); PFIL_LIST_UNLOCK(); TAILQ_FOREACH_SAFE(pfh, &ph->ph_in, pfil_link, pfnext) free(pfh, M_IFADDR); TAILQ_FOREACH_SAFE(pfh, &ph->ph_out, pfil_link, pfnext) free(pfh, M_IFADDR); PFIL_LOCK_DESTROY(ph); return (0); } /* * pfil_head_get() returns the pfil_head for a given key/dlt. */ struct pfil_head * pfil_head_get(int type, u_long val) { struct pfil_head *ph; PFIL_LIST_LOCK(); LIST_FOREACH(ph, &V_pfil_head_list, ph_list) if (ph->ph_type == type && ph->ph_un.phu_val == val) break; PFIL_LIST_UNLOCK(); return (ph); } /* * pfil_add_hook() adds a function to the packet filter hook. the * flags are: * PFIL_IN call me on incoming packets * PFIL_OUT call me on outgoing packets * PFIL_ALL call me on all of the above * PFIL_WAITOK OK to call malloc with M_WAITOK. */ int pfil_add_hook(int (*func)(void *, struct mbuf **, struct ifnet *, int, struct inpcb *), void *arg, int flags, struct pfil_head *ph) { struct packet_filter_hook *pfh1 = NULL; struct packet_filter_hook *pfh2 = NULL; int err; if (flags & PFIL_IN) { pfh1 = (struct packet_filter_hook *)malloc(sizeof(*pfh1), M_IFADDR, (flags & PFIL_WAITOK) ? M_WAITOK : M_NOWAIT); if (pfh1 == NULL) { err = ENOMEM; goto error; } } if (flags & PFIL_OUT) { pfh2 = (struct packet_filter_hook *)malloc(sizeof(*pfh1), M_IFADDR, (flags & PFIL_WAITOK) ? M_WAITOK : M_NOWAIT); if (pfh2 == NULL) { err = ENOMEM; goto error; } } PFIL_WLOCK(ph); if (flags & PFIL_IN) { pfh1->pfil_func = func; pfh1->pfil_arg = arg; err = pfil_list_add(&ph->ph_in, pfh1, flags & ~PFIL_OUT); if (err) goto locked_error; ph->ph_nhooks++; } if (flags & PFIL_OUT) { pfh2->pfil_func = func; pfh2->pfil_arg = arg; err = pfil_list_add(&ph->ph_out, pfh2, flags & ~PFIL_IN); if (err) { if (flags & PFIL_IN) pfil_list_remove(&ph->ph_in, func, arg); goto locked_error; } ph->ph_nhooks++; } PFIL_WUNLOCK(ph); return (0); locked_error: PFIL_WUNLOCK(ph); error: if (pfh1 != NULL) free(pfh1, M_IFADDR); if (pfh2 != NULL) free(pfh2, M_IFADDR); return (err); } /* * pfil_remove_hook removes a specific function from the packet filter hook * list. */ int pfil_remove_hook(int (*func)(void *, struct mbuf **, struct ifnet *, int, struct inpcb *), void *arg, int flags, struct pfil_head *ph) { int err = 0; PFIL_WLOCK(ph); if (flags & PFIL_IN) { err = pfil_list_remove(&ph->ph_in, func, arg); if (err == 0) ph->ph_nhooks--; } if ((err == 0) && (flags & PFIL_OUT)) { err = pfil_list_remove(&ph->ph_out, func, arg); if (err == 0) ph->ph_nhooks--; } PFIL_WUNLOCK(ph); return (err); } static int pfil_list_add(pfil_list_t *list, struct packet_filter_hook *pfh1, int flags) { struct packet_filter_hook *pfh; /* * First make sure the hook is not already there. */ TAILQ_FOREACH(pfh, list, pfil_link) if (pfh->pfil_func == pfh1->pfil_func && pfh->pfil_arg == pfh1->pfil_arg) return (EEXIST); /* * Insert the input list in reverse order of the output list so that * the same path is followed in or out of the kernel. */ if (flags & PFIL_IN) TAILQ_INSERT_HEAD(list, pfh1, pfil_link); else TAILQ_INSERT_TAIL(list, pfh1, pfil_link); return (0); } /* * pfil_list_remove is an internal function that takes a function off the * specified list. */ static int pfil_list_remove(pfil_list_t *list, int (*func)(void *, struct mbuf **, struct ifnet *, int, struct inpcb *), void *arg) { struct packet_filter_hook *pfh; TAILQ_FOREACH(pfh, list, pfil_link) if (pfh->pfil_func == func && pfh->pfil_arg == arg) { TAILQ_REMOVE(list, pfh, pfil_link); free(pfh, M_IFADDR); return (0); } return (ENOENT); } /* * Stuff that must be initialized for every instance (including the first of * course). */ static int vnet_pfil_init(const void *unused) { LIST_INIT(&V_pfil_head_list); return (0); } /* * Called for the removal of each instance. */ static int vnet_pfil_uninit(const void *unused) { /* XXX should panic if list is not empty */ return (0); } /* Define startup order. */ #define PFIL_SYSINIT_ORDER SI_SUB_PROTO_BEGIN #define PFIL_MODEVENT_ORDER (SI_ORDER_FIRST) /* On boot slot in here. */ #define PFIL_VNET_ORDER (PFIL_MODEVENT_ORDER + 2) /* Later still. */ /* * Starting up. * * VNET_SYSINIT is called for each existing vnet and each new vnet. */ VNET_SYSINIT(vnet_pfil_init, PFIL_SYSINIT_ORDER, PFIL_VNET_ORDER, vnet_pfil_init, NULL); /* * Closing up shop. These are done in REVERSE ORDER. Not called on reboot. * * VNET_SYSUNINIT is called for each exiting vnet as it exits. */ VNET_SYSUNINIT(vnet_pfil_uninit, PFIL_SYSINIT_ORDER, PFIL_VNET_ORDER, vnet_pfil_uninit, NULL);