diff options
author | sam <sam@FreeBSD.org> | 2003-09-23 17:54:04 +0000 |
---|---|---|
committer | sam <sam@FreeBSD.org> | 2003-09-23 17:54:04 +0000 |
commit | cd738e85741205de9f360fdbeaa49f30ce2038d9 (patch) | |
tree | c61b991702ec6f77c0e1b96cda74ae091fa2e749 /sys/net/pfil.c | |
parent | 655247e0f5d689da4bda90e946a5227f58670ef2 (diff) | |
download | FreeBSD-src-cd738e85741205de9f360fdbeaa49f30ce2038d9.zip FreeBSD-src-cd738e85741205de9f360fdbeaa49f30ce2038d9.tar.gz |
o update PFIL_HOOKS support to current API used by netbsd
o revamp IPv4+IPv6+bridge usage to match API changes
o remove pfil_head instances from protosw entries (no longer used)
o add locking
o bump FreeBSD version for 3rd party modules
Heavy lifting by: "Max Laier" <max@love2party.net>
Supported by: FreeBSD Foundation
Obtained from: NetBSD (bits of pfil.h and pfil.c)
Diffstat (limited to 'sys/net/pfil.c')
-rw-r--r-- | sys/net/pfil.c | 356 |
1 files changed, 280 insertions, 76 deletions
diff --git a/sys/net/pfil.c b/sys/net/pfil.c index 2ed40b2..c995ec2 100644 --- a/sys/net/pfil.c +++ b/sys/net/pfil.c @@ -1,4 +1,5 @@ -/* $FreeBSD$ */ +/* $FreeBSD$ */ +/* $NetBSD: pfil.c,v 1.20 2001/11/12 23:49:46 lukem Exp $ */ /* * Copyright (c) 1996 Matthew R. Green @@ -29,30 +30,198 @@ */ #include <sys/param.h> +#include <sys/kernel.h> #include <sys/errno.h> #include <sys/malloc.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 void pfil_init(struct pfil_head *); -static int pfil_list_add(pfil_list_t *, - int (*)(void *, int, struct ifnet *, int, struct mbuf **), int); +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 *, int, struct ifnet *, int, struct mbuf **)); + int (*)(void *, struct mbuf **, struct ifnet *, int), void *); + +LIST_HEAD(, pfil_head) pfil_head_list = + LIST_HEAD_INITIALIZER(&pfil_head_list); + +static __inline void +PFIL_RLOCK(struct pfil_head *ph) +{ + mtx_lock(&ph->ph_mtx); + ph->ph_busy_count++; + mtx_unlock(&ph->ph_mtx); +} + +static __inline void +PFIL_RUNLOCK(struct pfil_head *ph) +{ + mtx_lock(&ph->ph_mtx); + ph->ph_busy_count--; + if (ph->ph_busy_count == 0 && ph->ph_want_write) + cv_signal(&ph->ph_cv); + mtx_unlock(&ph->ph_mtx); +} + +static __inline void +PFIL_WLOCK(struct pfil_head *ph) +{ + mtx_lock(&ph->ph_mtx); + ph->ph_want_write = 1; + while (ph->ph_busy_count > 0) + cv_wait(&ph->ph_cv, &ph->ph_mtx); +} + +static __inline int +PFIL_TRY_WLOCK(struct pfil_head *ph) +{ + mtx_lock(&ph->ph_mtx); + ph->ph_want_write = 1; + if (ph->ph_busy_count > 0) { + ph->ph_want_write = 0; + mtx_unlock(&ph->ph_mtx); + return EBUSY; + } + return 0; +} + +static __inline void +PFIL_WUNLOCK(struct pfil_head *ph) +{ + ph->ph_want_write = 0; \ + mtx_unlock(&ph->ph_mtx); + cv_signal(&ph->ph_cv); +} -static void -pfil_init(ph) - struct pfil_head *ph; +#define PFIL_LIST_LOCK() mtx_lock(&pfil_global_lock) +#define PFIL_LIST_UNLOCK() mtx_unlock(&pfil_global_lock) + +/* + * 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 packet_filter_hook *pfh; + struct mbuf *m = *mp; + int rv = 0; + + if (ph->ph_busy_count == -1 || ph->ph_want_write) + return (0); + + PFIL_RLOCK(ph); + 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); + if (rv != 0 || m == NULL) + break; + } + } + PFIL_RUNLOCK(ph); + + *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, &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_LIST_UNLOCK(); + + if (mtx_initialized(&ph->ph_mtx)) { /* should not happen */ + KASSERT((0), ("%s: allready initialized!", __func__)); + return EBUSY; + } else { + ph->ph_busy_count = -1; + ph->ph_want_write = 1; + mtx_init(&ph->ph_mtx, "pfil_head_mtx", NULL, MTX_DEF); + cv_init(&ph->ph_cv, "pfil_head_cv"); + mtx_lock(&ph->ph_mtx); /* XXX: race? */ + } TAILQ_INIT(&ph->ph_in); TAILQ_INIT(&ph->ph_out); - ph->ph_init = 1; + + PFIL_LIST_LOCK(); + LIST_INSERT_HEAD(&pfil_head_list, ph, ph_list); + PFIL_LIST_UNLOCK(); + + PFIL_WUNLOCK(ph); + + return (0); +} + +/* + * pfil_head_unregister() removes a pfil_head from the packet filter + * hook mechanism. + */ +int +pfil_head_unregister(struct pfil_head *ph) +{ + struct packet_filter_hook *pfh, *pfnext; + + PFIL_LIST_LOCK(); + /* + * LIST_REMOVE is safe for unlocked pfil_heads in ph_list. + * No need to WLOCK all of them. + */ + LIST_REMOVE(ph, ph_list); + PFIL_LIST_UNLOCK(); + + PFIL_WLOCK(ph); /* XXX: may sleep (cv_wait)! */ + + 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); + cv_destroy(&ph->ph_cv); + mtx_destroy(&ph->ph_mtx); + + 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, &pfil_head_list, ph_list) + if (ph->ph_type == type && ph->ph_un.phu_val == val) + break; + PFIL_LIST_UNLOCK(); + + return (ph); } /* @@ -64,53 +233,71 @@ pfil_init(ph) * PFIL_WAITOK OK to call malloc with M_WAITOK. */ int -pfil_add_hook(func, flags, ph) - int (*func)(void *, int, struct ifnet *, int, struct mbuf **); - int flags; - struct pfil_head *ph; +pfil_add_hook(int (*func)(void *, struct mbuf **, struct ifnet *, int), + void *arg, int flags, struct pfil_head *ph) { - int err = 0; + struct packet_filter_hook *pfh1 = NULL; + struct packet_filter_hook *pfh2 = NULL; + int err; - if (ph->ph_init == 0) - pfil_init(ph); + /* Get memory */ + 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; + } + } - if (flags & PFIL_IN) - err = pfil_list_add(&ph->ph_in, func, flags & ~PFIL_OUT); - if (err) - return err; - if (flags & PFIL_OUT) - err = pfil_list_add(&ph->ph_out, func, flags & ~PFIL_IN); - if (err) { - if (flags & PFIL_IN) - pfil_list_remove(&ph->ph_in, func); - return err; + /* Lock */ + if (flags & PFIL_WAITOK) + PFIL_WLOCK(ph); + else { + err = PFIL_TRY_WLOCK(ph); + if (err) + goto error; } - return 0; -} -static int -pfil_list_add(list, func, flags) - pfil_list_t *list; - int (*func)(void *, int, struct ifnet *, int, struct mbuf **); - int flags; -{ - struct packet_filter_hook *pfh; + /* Add */ + 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 done; + } + 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 done; + } + } + + ph->ph_busy_count = 0; + PFIL_WUNLOCK(ph); - pfh = (struct packet_filter_hook *)malloc(sizeof(*pfh), M_IFADDR, - flags & PFIL_WAITOK ? M_WAITOK : M_NOWAIT); - if (pfh == NULL) - return ENOMEM; - pfh->pfil_func = func; - /* - * 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, pfh, pfil_link); - else - TAILQ_INSERT_TAIL(list, pfh, pfil_link); return 0; +done: + PFIL_WUNLOCK(ph); +error: + if (pfh1 != NULL) + free(pfh1, M_IFADDR); + if (pfh2 != NULL) + free(pfh2, M_IFADDR); + return err; } /* @@ -118,54 +305,71 @@ pfil_list_add(list, func, flags) * hook list. */ int -pfil_remove_hook(func, flags, ph) - int (*func)(void *, int, struct ifnet *, int, struct mbuf **); - int flags; - struct pfil_head *ph; +pfil_remove_hook(int (*func)(void *, struct mbuf **, struct ifnet *, int), + void *arg, int flags, struct pfil_head *ph) { int err = 0; - if (ph->ph_init == 0) - pfil_init(ph); + if (flags & PFIL_WAITOK) + PFIL_WLOCK(ph); + else { + err = PFIL_TRY_WLOCK(ph); + if (err) + return err; + } if (flags & PFIL_IN) - err = pfil_list_remove(&ph->ph_in, func); + err = pfil_list_remove(&ph->ph_in, func, arg); if ((err == 0) && (flags & PFIL_OUT)) - err = pfil_list_remove(&ph->ph_out, func); + err = pfil_list_remove(&ph->ph_out, func, arg); + + if (TAILQ_EMPTY(&ph->ph_in) && TAILQ_EMPTY(&ph->ph_out)) + ph->ph_busy_count = -1; + + 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(list, func) - pfil_list_t *list; - int (*func)(void *, int, struct ifnet *, int, struct mbuf **); +pfil_list_remove(pfil_list_t *list, + int (*func)(void *, struct mbuf **, struct ifnet *, int), void *arg) { struct packet_filter_hook *pfh; TAILQ_FOREACH(pfh, list, pfil_link) - if (pfh->pfil_func == func) { + if (pfh->pfil_func == func && pfh->pfil_arg == arg) { TAILQ_REMOVE(list, pfh, pfil_link); free(pfh, M_IFADDR); return 0; } return ENOENT; } - -struct packet_filter_hook * -pfil_hook_get(flag, ph) - int flag; - struct pfil_head *ph; -{ - if (ph->ph_init != 0) - switch (flag) { - case PFIL_IN: - return (TAILQ_FIRST(&ph->ph_in)); - case PFIL_OUT: - return (TAILQ_FIRST(&ph->ph_out)); - } - return NULL; -} |