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author | piso <piso@FreeBSD.org> | 2006-09-26 23:26:53 +0000 |
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committer | piso <piso@FreeBSD.org> | 2006-09-26 23:26:53 +0000 |
commit | 5582e56d9d09f5f753111b270859af3d97ffd499 (patch) | |
tree | 5e258090de6b0498a8722ea100fedca736af05b6 /sys/netinet/libalias/alias_mod.c | |
parent | e502090edb1afbf157ab5a195f23b62ac65279e1 (diff) | |
download | FreeBSD-src-5582e56d9d09f5f753111b270859af3d97ffd499.zip FreeBSD-src-5582e56d9d09f5f753111b270859af3d97ffd499.tar.gz |
Summer of Code 2005: improve libalias - part 1 of 2
With the first part of my previous Summer of Code work, we get:
-made libalias modular:
-support for 'particular' protocols (like ftp/irc/etcetc) is no more
hardcoded inside libalias, but it's available through external
modules loadable at runtime
-modules are available both in kernel (/boot/kernel/alias_*.ko) and
user land (/lib/libalias_*)
-protocols/applications modularized are: cuseeme, ftp, irc, nbt, pptp,
skinny and smedia
-added logging support for kernel side
-cleanup
After a buildworld, do a 'mergemaster -i' to install the file libalias.conf
in /etc or manually copy it.
During startup (and after every HUP signal) user land applications running
the new libalias will try to read a file in /etc called libalias.conf:
that file contains the list of modules to load.
User land applications affected by this commit are ppp and natd:
if libalias.conf is present in /etc you won't notice any difference.
The only kernel land bit affected by this commit is ng_nat:
if you are using ng_nat, and it doesn't correctly handle
ftp/irc/etcetc sessions anymore, remember to kldload
the correspondent module (i.e. kldload alias_ftp).
General information and details about the inner working are available
in the libalias man page under the section 'MODULAR ARCHITECTURE
(AND ipfw(4) SUPPORT)'.
NOTA BENE: this commit affects _ONLY_ libalias, ipfw in-kernel nat
support will be part of the next libalias-related commit.
Approved by: glebius
Reviewed by: glebius, ru
Diffstat (limited to 'sys/netinet/libalias/alias_mod.c')
-rw-r--r-- | sys/netinet/libalias/alias_mod.c | 284 |
1 files changed, 284 insertions, 0 deletions
diff --git a/sys/netinet/libalias/alias_mod.c b/sys/netinet/libalias/alias_mod.c new file mode 100644 index 0000000..71192e9 --- /dev/null +++ b/sys/netinet/libalias/alias_mod.c @@ -0,0 +1,284 @@ +/*- + * Copyright (c) 2005 Paolo Pisati <piso@FreeBSD.org> + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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. + * + */ +__FBSDID("$FreeBSD$"); + + +#ifdef _KERNEL +#include <sys/libkern.h> +#include <sys/param.h> +#include <sys/lock.h> +#include <sys/rwlock.h> +#else +#include <stdio.h> +#include <string.h> +#include <sys/types.h> +#include <errno.h> +#endif + +#include <netinet/in_systm.h> +#include <netinet/in.h> +#include <netinet/ip.h> + +#ifdef _KERNEL +#include <netinet/libalias/alias_local.h> +#include <netinet/libalias/alias_mod.h> +#else +#include "alias_local.h" +#include "alias_mod.h" +#endif + +/* Protocol and userland module handlers chains. */ +LIST_HEAD(handler_chain, proto_handler) handler_chain = LIST_HEAD_INITIALIZER(foo); +#ifdef _KERNEL +struct rwlock handler_rw; +#endif +SLIST_HEAD(dll_chain, dll) dll_chain = SLIST_HEAD_INITIALIZER(foo); + +#ifdef _KERNEL + +#define LIBALIAS_LOCK_INIT() \ + rw_init(&handler_rw, "Libalias_modules_rwlock") +#define LIBALIAS_LOCK_DESTROY() rw_destroy(&handler_rw) +#define LIBALIAS_WLOCK_ASSERT() \ + rw_assert(&handler_rw, RA_WLOCKED) + +static __inline void +LIBALIAS_RLOCK(void) +{ + rw_rlock(&handler_rw); +} + +static __inline void +LIBALIAS_RUNLOCK(void) +{ + rw_runlock(&handler_rw); +} + +static __inline void +LIBALIAS_WLOCK(void) +{ + rw_wlock(&handler_rw); +} + +static __inline void +LIBALIAS_WUNLOCK(void) +{ + rw_wunlock(&handler_rw); +} + +static void +_handler_chain_init(void) +{ + + if (!rw_initialized(&handler_rw)) + LIBALIAS_LOCK_INIT(); +} + +static void +_handler_chain_destroy(void) +{ + + if (rw_initialized(&handler_rw)) + LIBALIAS_LOCK_DESTROY(); +} + +#else +#define LIBALIAS_LOCK_INIT() ; +#define LIBALIAS_LOCK_DESTROY() ; +#define LIBALIAS_WLOCK_ASSERT() ; +#define LIBALIAS_RLOCK() ; +#define LIBALIAS_RUNLOCK() ; +#define LIBALIAS_WLOCK() ; +#define LIBALIAS_WUNLOCK() ; +#define _handler_chain_init() ; +#define _handler_chain_destroy() ; +#endif + +void +handler_chain_init(void) +{ + _handler_chain_init(); +} + +void +handler_chain_destroy(void) +{ + _handler_chain_destroy(); +} + +static int +_attach_handler(struct proto_handler *p) +{ + struct proto_handler *b = NULL; + + LIBALIAS_WLOCK_ASSERT(); + LIST_FOREACH(b, &handler_chain, entries) { + if ((b->pri == p->pri) && + (b->dir == p->dir) && + (b->proto == p->proto)) + return (EEXIST); /* Priority conflict. */ + if (b->pri > p->pri) { + LIST_INSERT_BEFORE(b, p, entries); + return (0); + } + } + /* End of list or found right position, inserts here. */ + if (b) + LIST_INSERT_AFTER(b, p, entries); + else + LIST_INSERT_HEAD(&handler_chain, p, entries); + return (0); +} + +static int +_detach_handler(struct proto_handler *p) +{ + struct proto_handler *b, *b_tmp;; + + LIBALIAS_WLOCK_ASSERT(); + LIST_FOREACH_SAFE(b, &handler_chain, entries, b_tmp) { + if (b == p) { + LIST_REMOVE(b, entries); + return (0); + } + } + return (ENOENT); /* Handler not found. */ +} + +int +LibAliasAttachHandlers(struct proto_handler *_p) +{ + int i, error = -1; + + LIBALIAS_WLOCK(); + for (i=0; 1; i++) { + if (*((int *)&_p[i]) == EOH) + break; + error = _attach_handler(&_p[i]); + if (error != 0) + break; + } + LIBALIAS_WUNLOCK(); + return (error); +} + +int +LibAliasDetachHandlers(struct proto_handler *_p) +{ + int i, error = -1; + + LIBALIAS_WLOCK(); + for (i=0; 1; i++) { + if (*((int *)&_p[i]) == EOH) + break; + error = _detach_handler(&_p[i]); + if (error != 0) + break; + } + LIBALIAS_WUNLOCK(); + return (error); +} + +int +detach_handler(struct proto_handler *_p) +{ + int error = -1; + + LIBALIAS_WLOCK(); + error = _detach_handler(_p); + LIBALIAS_WUNLOCK(); + return (error); +} + +int +find_handler(int8_t dir, int8_t proto, struct libalias *la, struct ip *pip, + struct alias_data *ad) +{ + struct proto_handler *p; + int error = ENOENT; + + LIBALIAS_RLOCK(); + + LIST_FOREACH(p, &handler_chain, entries) { + if ((p->dir & dir) && (p->proto & proto)) + if (p->fingerprint(la, pip, ad) == 0) { + error = p->protohandler(la, pip, ad); + break; + } + } + LIBALIAS_RUNLOCK(); + return (error); +} + +struct proto_handler * +first_handler(void) +{ + + return (LIST_FIRST(&handler_chain)); +} + +/* Dll manipulation code - this code is not thread safe... */ + +int +attach_dll(struct dll *p) +{ + struct dll *b; + + SLIST_FOREACH(b, &dll_chain, next) { + if (!strncmp(b->name, p->name, DLL_LEN)) + return (EEXIST); /* Dll name conflict. */ + } + SLIST_INSERT_HEAD(&dll_chain, p, next); + return (0); +} + +void * +detach_dll(char *p) +{ + struct dll *b = NULL, *b_tmp; + void *error = NULL; + + SLIST_FOREACH_SAFE(b, &dll_chain, next, b_tmp) + if (!strncmp(b->name, p, DLL_LEN)) { + SLIST_REMOVE(&dll_chain, b, dll, next); + error = b; + break; + } + return (error); +} + +struct dll * +walk_dll_chain(void) +{ + struct dll *t; + + t = SLIST_FIRST(&dll_chain); + if (t == NULL) + return (NULL); + SLIST_REMOVE_HEAD(&dll_chain, next); + return (t); +} |