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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_dummy.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_dummy.c')
-rw-r--r-- | sys/netinet/libalias/alias_dummy.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/sys/netinet/libalias/alias_dummy.c b/sys/netinet/libalias/alias_dummy.c new file mode 100644 index 0000000..fc6a0f9 --- /dev/null +++ b/sys/netinet/libalias/alias_dummy.c @@ -0,0 +1,153 @@ +/*- + * 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. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +/* + * Alias_dummy is just an empty skeleton used to demostrate how to write + * a module for libalias, that will run unalterated in userland or in + * kernel land. + */ + +#ifdef _KERNEL +#include <sys/param.h> +#include <sys/kernel.h> +#include <sys/module.h> +#else +#include <errno.h> +#include <sys/types.h> +#include <stdio.h> +#endif + +#include <netinet/in_systm.h> +#include <netinet/in.h> +#include <netinet/ip.h> +#include <netinet/udp.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 + +static void +AliasHandleDummy(struct libalias *la, struct ip *ip, struct alias_data *ah); + +static int +fingerprint(struct libalias *la, struct ip *pip, struct alias_data *ah) +{ + + /* + * Check here all the data that will be used later, if any field + * is empy/NULL, return a -1 value. + */ + if (ah->dport == NULL || ah->sport == NULL || ah->lnk == NULL || + ah->maxpktsize == 0) + return (-1); + /* + * Fingerprint the incoming packet, if it matches any conditions + * return an OK value. + */ + if (ntohs(*ah->dport) == 123 + || ntohs(*ah->sport) == 456) + return (0); /* I know how to handle it. */ + return (-1); /* I don't recognize this packet. */ +} + +/* + * Wrap in this general purpose function, the real function used to alias the + * packets. + */ + +static int +protohandler(struct libalias *la, struct ip *pip, struct alias_data *ah) +{ + + AliasHandleDummy(la, pip, ah); + return (0); +} + +/* + * NOTA BENE: the next variable MUST NOT be renamed in any case if you want + * your module to work in userland, cause it's used to find and use all + * the protocol handlers present in every module. + * So WATCH OUT, your module needs this variables and it needs it with + * ITS EXACT NAME: handlers. + */ + +struct proto_handler handlers [] = { + { + .pri = 666, + .dir = IN|OUT, + .proto = UDP|TCP, + .fingerprint = &fingerprint, + .protohandler = &protohandler + }, + { EOH } +}; + +static int +mod_handler(module_t mod, int type, void *data) +{ + int error; + + switch (type) { + case MOD_LOAD: + error = 0; + LibAliasAttachHandlers(handlers); + break; + case MOD_UNLOAD: + error = 0; + LibAliasDetachHandlers(handlers); + break; + default: + error = EINVAL; + } + return (error); +} + +#ifdef _KERNEL +static +#endif +moduledata_t alias_mod = { + "alias_dummy", mod_handler, NULL +}; + +#ifdef _KERNEL +DECLARE_MODULE(alias_dummy, alias_mod, SI_SUB_DRIVERS, SI_ORDER_SECOND); +MODULE_VERSION(alias_dummy, 1); +MODULE_DEPEND(alias_dummy, libalias, 1, 1, 1); +#endif + +static void +AliasHandleDummy(struct libalias *la, struct ip *ip, struct alias_data *ah) +{ + ; /* Dummy. */ +} + |