535e0a0981
- Remove locking, since all module(9) events are running under &Giant. - Use TAILQ for protocol handlers and fix a bug which led to infinite cycle. Bug found in VirtualBox [1] - Simplify code everywhere. - Fix documentation. [1] https://www.virtualbox.org/pipermail/vbox-dev/2013-November/011936.html PR: 183792 [1] Submitted by: Valery Ushakov <uwe NetBSD.org> [1] Sponsored by: Nginx, Inc.
148 lines
4.4 KiB
C
148 lines
4.4 KiB
C
/*-
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* Copyright (c) 2005 Paolo Pisati <piso@FreeBSD.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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/*
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* Alias_mod.h defines the outside world interfaces for the packet aliasing
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* modular framework
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*/
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#ifndef _ALIAS_MOD_H_
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#define _ALIAS_MOD_H_
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#ifdef _KERNEL
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MALLOC_DECLARE(M_ALIAS);
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/* Use kernel allocator. */
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#if defined(_SYS_MALLOC_H_)
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#define malloc(x) malloc(x, M_ALIAS, M_NOWAIT|M_ZERO)
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#define calloc(x, n) malloc(x*n)
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#define free(x) free(x, M_ALIAS)
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#endif
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#endif
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/* Packet flow direction flags. */
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#define IN 0x0001
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#define OUT 0x0002
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#define NODIR 0x4000
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/* Working protocol flags. */
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#define IP 0x01
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#define TCP 0x02
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#define UDP 0x04
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/*
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* Data passed to protocol handler module, it must be filled
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* right before calling find_handler() to determine which
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* module is elegible to be called.
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*/
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struct alias_data {
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struct alias_link *lnk;
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struct in_addr *oaddr; /* Original address. */
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struct in_addr *aaddr; /* Alias address. */
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uint16_t *aport; /* Alias port. */
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uint16_t *sport, *dport; /* Source & destination port */
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uint16_t maxpktsize; /* Max packet size. */
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};
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/*
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* This structure contains all the information necessary to make
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* a protocol handler correctly work.
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*/
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struct proto_handler {
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u_int pri; /* Handler priority. */
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int16_t dir; /* Flow direction. */
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uint8_t proto; /* Working protocol. */
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/* Fingerprint * function. */
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int (*fingerprint)(struct libalias *, struct alias_data *);
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/* Aliasing * function. */
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int (*protohandler)(struct libalias *, struct ip *,
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struct alias_data *);
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TAILQ_ENTRY(proto_handler) link;
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};
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/* End of handlers. */
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#define EOH .dir = NODIR
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/* Functions used with protocol handlers. */
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int LibAliasAttachHandlers(struct proto_handler *);
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int LibAliasDetachHandlers(struct proto_handler *);
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int find_handler(int8_t, int8_t, struct libalias *, struct ip *,
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struct alias_data *);
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struct proto_handler *first_handler(void);
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#ifndef _KERNEL
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/*
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* Used only in userland when libalias needs to keep track of all
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* module loaded. In kernel land (kld mode) we don't need to care
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* care about libalias modules cause it's kld to do it for us.
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*/
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#define DLL_LEN 32
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struct dll {
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char name[DLL_LEN]; /* Name of module. */
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void *handle; /*
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* Ptr to shared obj obtained through
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* dlopen() - use this ptr to get access
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* to any symbols from a loaded module
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* via dlsym().
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*/
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SLIST_ENTRY(dll) next;
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};
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/* Functions used with dll module. */
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void dll_chain_init(void);
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void dll_chain_destroy(void);
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int attach_dll(struct dll *);
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void *detach_dll(char *);
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struct dll *walk_dll_chain(void);
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/*
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* Some defines borrowed from sys/module.h used to compile a kld
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* in userland as a shared lib.
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*/
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typedef enum modeventtype {
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MOD_LOAD,
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MOD_UNLOAD,
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MOD_SHUTDOWN,
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MOD_QUIESCE
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} modeventtype_t;
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typedef struct module *module_t;
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typedef int (*modeventhand_t)(module_t, int /* modeventtype_t */, void *);
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/*
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* Struct for registering modules statically via SYSINIT.
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*/
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typedef struct moduledata {
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const char *name; /* module name */
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modeventhand_t evhand; /* event handler */
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void *priv; /* extra data */
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} moduledata_t;
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#endif /* !_KERNEL */
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#endif /* !_ALIAS_MOD_H_ */
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