+++ /dev/null
---- /dev/null
-+++ b/include/linux/netfilter_ipv4/ipt_string.h
-@@ -0,0 +1,18 @@
-+#ifndef _IPT_STRING_H
-+#define _IPT_STRING_H
-+
-+#define IPT_STRING_MAX_PATTERN_SIZE 128
-+#define IPT_STRING_MAX_ALGO_NAME_SIZE 16
-+
-+struct ipt_string_info
-+{
-+ u_int16_t from_offset;
-+ u_int16_t to_offset;
-+ char algo[IPT_STRING_MAX_ALGO_NAME_SIZE];
-+ char pattern[IPT_STRING_MAX_PATTERN_SIZE];
-+ u_int8_t patlen;
-+ u_int8_t invert;
-+ struct ts_config __attribute__((aligned(8))) *config;
-+};
-+
-+#endif /*_IPT_STRING_H*/
---- a/net/ipv4/netfilter/Config.in
-+++ b/net/ipv4/netfilter/Config.in
-@@ -47,6 +47,7 @@ if [ "$CONFIG_IP_NF_IPTABLES" != "n" ];
- fi
- if [ "$CONFIG_EXPERIMENTAL" = "y" ]; then
- dep_tristate ' Unclean match support (EXPERIMENTAL)' CONFIG_IP_NF_MATCH_UNCLEAN $CONFIG_IP_NF_IPTABLES
-+ dep_tristate ' String match support (EXPERIMENTAL) ' CONFIG_IP_NF_MATCH_STRING $CONFIG_IP_NF_IPTABLES
- dep_tristate ' Owner match support (EXPERIMENTAL)' CONFIG_IP_NF_MATCH_OWNER $CONFIG_IP_NF_IPTABLES
- dep_tristate ' Layer 7 match support (EXPERIMENTAL)' CONFIG_IP_NF_MATCH_LAYER7 $CONFIG_IP_NF_CONNTRACK
- dep_mbool ' Layer 7 debugging output (EXPERIMENTAL)' CONFIG_IP_NF_MATCH_LAYER7_DEBUG $CONFIG_IP_NF_MATCH_LAYER7
---- /dev/null
-+++ b/net/ipv4/netfilter/ipt_string.c
-@@ -0,0 +1,99 @@
-+/* String matching match for iptables
-+ *
-+ * (C) 2005 Pablo Neira Ayuso <pablo@eurodev.net>
-+ *
-+ * This program is free software; you can redistribute it and/or modify
-+ * it under the terms of the GNU General Public License version 2 as
-+ * published by the Free Software Foundation.
-+ */
-+
-+#include <linux/init.h>
-+#include <linux/module.h>
-+#include <linux/kernel.h>
-+#include <linux/skbuff.h>
-+#include <linux/netfilter_ipv4/ip_tables.h>
-+#include <linux/netfilter_ipv4/ipt_string.h>
-+#include "textsearch/textsearch.h"
-+#include "textsearch/textsearch.c"
-+#include "textsearch/ts_bm.c"
-+#include "textsearch/ts_kmp.c"
-+
-+MODULE_AUTHOR("Pablo Neira Ayuso <pablo@eurodev.net>");
-+MODULE_DESCRIPTION("IP tables string match module");
-+MODULE_LICENSE("GPL");
-+
-+static int match(const struct sk_buff *skb,
-+ const struct net_device *in,
-+ const struct net_device *out,
-+ const void *matchinfo,
-+ int offset,
-+ int *hotdrop)
-+{
-+ struct iphdr *ip = skb->nh.iph;
-+ struct ts_state state;
-+ struct ipt_string_info *conf = (struct ipt_string_info *) matchinfo;
-+ char *buf = (char *)ip+(ip->ihl*4);
-+ int len = ntohs(ip->tot_len)-(ip->ihl*4);
-+
-+ memset(&state, 0, sizeof(struct ts_state));
-+
-+ return (textsearch_find_continuous(conf->config, &state, buf, len) != UINT_MAX) && !conf->invert;
-+}
-+
-+#define STRING_TEXT_PRIV(m) ((struct ipt_string_info *) m)
-+
-+static int checkentry(const char *tablename,
-+ const struct ipt_ip *ip,
-+ void *matchinfo,
-+ unsigned int matchsize,
-+ unsigned int hook_mask)
-+{
-+ struct ipt_string_info *conf = matchinfo;
-+ struct ts_config *ts_conf;
-+
-+ if (matchsize != IPT_ALIGN(sizeof(struct ipt_string_info)))
-+ return 0;
-+
-+ /* Damn, can't handle this case properly with iptables... */
-+ if (conf->from_offset > conf->to_offset)
-+ return 0;
-+
-+ ts_conf = textsearch_prepare(conf->algo, conf->pattern, conf->patlen,
-+ GFP_KERNEL, TS_AUTOLOAD);
-+ if (IS_ERR(ts_conf))
-+ return 0;
-+
-+ conf->config = ts_conf;
-+
-+ return 1;
-+}
-+
-+static void destroy(void *matchinfo, unsigned int matchsize)
-+{
-+ textsearch_destroy(STRING_TEXT_PRIV(matchinfo)->config);
-+}
-+
-+static struct ipt_match string_match = {
-+ .name = "string",
-+ .match = match,
-+ .checkentry = checkentry,
-+ .destroy = destroy,
-+ .me = THIS_MODULE
-+};
-+
-+static int __init init(void)
-+{
-+ init_bm();
-+ init_kmp();
-+ return ipt_register_match(&string_match);
-+}
-+
-+static void __exit fini(void)
-+{
-+ exit_kmp();
-+ exit_bm();
-+ ipt_unregister_match(&string_match);
-+}
-+
-+module_init(init);
-+module_exit(fini);
---- a/net/ipv4/netfilter/Makefile
-+++ b/net/ipv4/netfilter/Makefile
-@@ -87,6 +87,7 @@ obj-$(CONFIG_IP_NF_MATCH_STATE) += ipt_s
- obj-$(CONFIG_IP_NF_MATCH_CONNMARK) += ipt_connmark.o
- obj-$(CONFIG_IP_NF_MATCH_CONNTRACK) += ipt_conntrack.o
- obj-$(CONFIG_IP_NF_MATCH_UNCLEAN) += ipt_unclean.o
-+obj-$(CONFIG_IP_NF_MATCH_STRING) += ipt_string.o
- obj-$(CONFIG_IP_NF_MATCH_TCPMSS) += ipt_tcpmss.o
- obj-$(CONFIG_IP_NF_MATCH_LAYER7) += ipt_layer7.o
-
---- /dev/null
-+++ b/net/ipv4/netfilter/textsearch/textsearch.c
-@@ -0,0 +1,305 @@
-+/*
-+ * lib/textsearch.c Generic text search interface
-+ *
-+ * This program is free software; you can redistribute it and/or
-+ * modify it under the terms of the GNU General Public License
-+ * as published by the Free Software Foundation; either version
-+ * 2 of the License, or (at your option) any later version.
-+ *
-+ * Authors: Thomas Graf <tgraf@suug.ch>
-+ * Pablo Neira Ayuso <pablo@eurodev.net>
-+ *
-+ * ==========================================================================
-+ *
-+ * INTRODUCTION
-+ *
-+ * The textsearch infrastructure provides text searching facitilies for
-+ * both linear and non-linear data. Individual search algorithms are
-+ * implemented in modules and chosen by the user.
-+ *
-+ * ARCHITECTURE
-+ *
-+ * User
-+ * +----------------+
-+ * | finish()|<--------------(6)-----------------+
-+ * |get_next_block()|<--------------(5)---------------+ |
-+ * | | Algorithm | |
-+ * | | +------------------------------+
-+ * | | | init() find() destroy() |
-+ * | | +------------------------------+
-+ * | | Core API ^ ^ ^
-+ * | | +---------------+ (2) (4) (8)
-+ * | (1)|----->| prepare() |---+ | |
-+ * | (3)|----->| find()/next() |-----------+ |
-+ * | (7)|----->| destroy() |----------------------+
-+ * +----------------+ +---------------+
-+ *
-+ * (1) User configures a search by calling _prepare() specifying the
-+ * search parameters such as the pattern and algorithm name.
-+ * (2) Core requests the algorithm to allocate and initialize a search
-+ * configuration according to the specified parameters.
-+ * (3) User starts the search(es) by calling _find() or _next() to
-+ * fetch subsequent occurrences. A state variable is provided
-+ * to the algorihtm to store persistant variables.
-+ * (4) Core eventually resets the search offset and forwards the find()
-+ * request to the algorithm.
-+ * (5) Algorithm calls get_next_block() provided by the user continously
-+ * to fetch the data to be searched in block by block.
-+ * (6) Algorithm invokes finish() after the last call to get_next_block
-+ * to clean up any leftovers from get_next_block. (Optional)
-+ * (7) User destroys the configuration by calling _destroy().
-+ * (8) Core notifies the algorithm to destroy algorithm specific
-+ * allocations. (Optional)
-+ *
-+ * USAGE
-+ *
-+ * Before a search can be performed, a configuration must be created
-+ * by calling textsearch_prepare() specyfing the searching algorithm and
-+ * the pattern to look for. The returned configuration may then be used
-+ * for an arbitary amount of times and even in parallel as long as a
-+ * separate struct ts_state variable is provided to every instance.
-+ *
-+ * The actual search is performed by either calling textsearch_find_-
-+ * continuous() for linear data or by providing an own get_next_block()
-+ * implementation and calling textsearch_find(). Both functions return
-+ * the position of the first occurrence of the patern or UINT_MAX if
-+ * no match was found. Subsequent occurences can be found by calling
-+ * textsearch_next() regardless of the linearity of the data.
-+ *
-+ * Once you're done using a configuration it must be given back via
-+ * textsearch_destroy.
-+ *
-+ * EXAMPLE
-+ *
-+ * int pos;
-+ * struct ts_config *conf;
-+ * struct ts_state state;
-+ * const char *pattern = "chicken";
-+ * const char *example = "We dance the funky chicken";
-+ *
-+ * conf = textsearch_prepare("kmp", pattern, strlen(pattern),
-+ * GFP_KERNEL, TS_AUTOLOAD);
-+ * if (IS_ERR(conf)) {
-+ * err = PTR_ERR(conf);
-+ * goto errout;
-+ * }
-+ *
-+ * pos = textsearch_find_continuous(conf, &state, example, strlen(example));
-+ * if (pos != UINT_MAX)
-+ * panic("Oh my god, dancing chickens at %d\n", pos);
-+ *
-+ * textsearch_destroy(conf);
-+ *
-+ * ==========================================================================
-+ */
-+
-+#include <linux/config.h>
-+#include <linux/module.h>
-+#include <linux/types.h>
-+#include <linux/string.h>
-+#include <linux/init.h>
-+#include <linux/netfilter_ipv4/lockhelp.h>
-+#include "textsearch.h"
-+
-+static LIST_HEAD(ts_ops);
-+static spinlock_t ts_mod_lock = SPIN_LOCK_UNLOCKED;
-+static DECLARE_RWLOCK(ts_ops_lock);
-+
-+static inline struct ts_ops *lookup_ts_algo(const char *name)
-+{
-+ struct ts_ops *o;
-+
-+ read_lock(&ts_ops_lock);
-+ list_for_each_entry(o, &ts_ops, list) {
-+ if (!strcmp(name, o->name)) {
-+ MOD_INC_USE_COUNT;
-+ read_unlock(&ts_ops_lock);
-+ return o;
-+ }
-+ }
-+ read_unlock(&ts_ops_lock);
-+
-+ return NULL;
-+}
-+
-+/**
-+ * textsearch_register - register a textsearch module
-+ * @ops: operations lookup table
-+ *
-+ * This function must be called by textsearch modules to announce
-+ * their presence. The specified &@ops must have %name set to a
-+ * unique identifier and the callbacks find(), init(), get_pattern(),
-+ * and get_pattern_len() must be implemented.
-+ *
-+ * Returns 0 or -EEXISTS if another module has already registered
-+ * with same name.
-+ */
-+int textsearch_register(struct ts_ops *ops)
-+{
-+ int err = -EEXIST;
-+ struct ts_ops *o;
-+
-+ if (ops->name == NULL || ops->find == NULL || ops->init == NULL ||
-+ ops->get_pattern == NULL || ops->get_pattern_len == NULL)
-+ return -EINVAL;
-+
-+ spin_lock(&ts_mod_lock);
-+ list_for_each_entry(o, &ts_ops, list) {
-+ if (!strcmp(ops->name, o->name))
-+ goto errout;
-+ }
-+
-+ write_lock(&ts_ops_lock);
-+ list_add_tail(&ops->list, &ts_ops);
-+ write_unlock(&ts_ops_lock);
-+
-+ err = 0;
-+errout:
-+ spin_unlock(&ts_mod_lock);
-+ return err;
-+}
-+
-+/**
-+ * textsearch_unregister - unregister a textsearch module
-+ * @ops: operations lookup table
-+ *
-+ * This function must be called by textsearch modules to announce
-+ * their disappearance for examples when the module gets unloaded.
-+ * The &ops parameter must be the same as the one during the
-+ * registration.
-+ *
-+ * Returns 0 on success or -ENOENT if no matching textsearch
-+ * registration was found.
-+ */
-+int textsearch_unregister(struct ts_ops *ops)
-+{
-+ int err = 0;
-+ struct ts_ops *o;
-+
-+ spin_lock(&ts_mod_lock);
-+ list_for_each_entry(o, &ts_ops, list) {
-+ if (o == ops) {
-+ write_lock(&ts_ops_lock);
-+ list_del(&o->list);
-+ write_unlock(&ts_ops_lock);
-+ goto out;
-+ }
-+ }
-+
-+ err = -ENOENT;
-+out:
-+ spin_unlock(&ts_mod_lock);
-+ return err;
-+}
-+
-+struct ts_linear_state
-+{
-+ unsigned int len;
-+ const void *data;
-+};
-+
-+static unsigned int get_linear_data(unsigned int consumed, const u8 **dst,
-+ struct ts_config *conf,
-+ struct ts_state *state)
-+{
-+ struct ts_linear_state *st = (struct ts_linear_state *) state->cb;
-+
-+ if (likely(consumed < st->len)) {
-+ *dst = st->data + consumed;
-+ return st->len - consumed;
-+ }
-+
-+ return 0;
-+}
-+
-+/**
-+ * textsearch_find_continuous - search a pattern in continuous/linear data
-+ * @conf: search configuration
-+ * @state: search state
-+ * @data: data to search in
-+ * @len: length of data
-+ *
-+ * A simplified version of textsearch_find() for continuous/linear data.
-+ * Call textsearch_next() to retrieve subsequent matches.
-+ *
-+ * Returns the position of first occurrence of the pattern or
-+ * UINT_MAX if no occurrence was found.
-+ */
-+unsigned int textsearch_find_continuous(struct ts_config *conf,
-+ struct ts_state *state,
-+ const void *data, unsigned int len)
-+{
-+ struct ts_linear_state *st = (struct ts_linear_state *) state->cb;
-+
-+ conf->get_next_block = get_linear_data;
-+ st->data = data;
-+ st->len = len;
-+
-+ return textsearch_find(conf, state);
-+}
-+
-+/**
-+ * textsearch_prepare - Prepare a search
-+ * @algo: name of search algorithm
-+ * @pattern: pattern data
-+ * @len: length of pattern
-+ * @gfp_mask: allocation mask
-+ * @flags: search flags
-+ *
-+ * Looks up the search algorithm module and creates a new textsearch
-+ * configuration for the specified pattern. Upon completion all
-+ * necessary refcnts are held and the configuration must be put back
-+ * using textsearch_put() after usage.
-+ *
-+ * Note: The format of the pattern may not be compatible between
-+ * the various search algorithms.
-+ *
-+ * Returns a new textsearch configuration according to the specified
-+ * parameters or a ERR_PTR().
-+ */
-+struct ts_config *textsearch_prepare(const char *algo, const void *pattern,
-+ unsigned int len, gfp_t gfp_mask, int flags)
-+{
-+ int err = -ENOENT;
-+ struct ts_config *conf;
-+ struct ts_ops *ops;
-+
-+ ops = lookup_ts_algo(algo);
-+
-+ if (ops == NULL)
-+ goto errout;
-+
-+ conf = ops->init(pattern, len, gfp_mask);
-+ if (IS_ERR(conf)) {
-+ err = PTR_ERR(conf);
-+ goto errout;
-+ }
-+
-+ conf->ops = ops;
-+ return conf;
-+
-+errout:
-+ if (ops)
-+ MOD_DEC_USE_COUNT;
-+
-+ return ERR_PTR(err);
-+}
-+
-+/**
-+ * textsearch_destroy - destroy a search configuration
-+ * @conf: search configuration
-+ *
-+ * Releases all references of the configuration and frees
-+ * up the memory.
-+ */
-+void textsearch_destroy(struct ts_config *conf)
-+{
-+ if (conf->ops) {
-+ if (conf->ops->destroy)
-+ conf->ops->destroy(conf);
-+ MOD_DEC_USE_COUNT;
-+ }
-+
-+ kfree(conf);
-+}
-+
---- /dev/null
-+++ b/net/ipv4/netfilter/textsearch/textsearch.h
-@@ -0,0 +1,182 @@
-+#ifndef __LINUX_TEXTSEARCH_H
-+#define __LINUX_TEXTSEARCH_H
-+
-+#ifdef __KERNEL__
-+
-+#include <linux/types.h>
-+#include <linux/list.h>
-+#include <linux/kernel.h>
-+#include <linux/module.h>
-+#include <linux/slab.h>
-+
-+typedef int gfp_t;
-+struct ts_config;
-+
-+/**
-+ * TS_AUTOLOAD - Automatically load textsearch modules when needed
-+ */
-+#define TS_AUTOLOAD 1
-+
-+/**
-+ * struct ts_state - search state
-+ * @offset: offset for next match
-+ * @cb: control buffer, for persistant variables of get_next_block()
-+ */
-+struct ts_state
-+{
-+ unsigned int offset;
-+ char cb[40];
-+};
-+
-+/**
-+ * struct ts_ops - search module operations
-+ * @name: name of search algorithm
-+ * @init: initialization function to prepare a search
-+ * @find: find the next occurrence of the pattern
-+ * @destroy: destroy algorithm specific parts of a search configuration
-+ * @get_pattern: return head of pattern
-+ * @get_pattern_len: return length of pattern
-+ * @owner: module reference to algorithm
-+ */
-+struct ts_ops
-+{
-+ const char *name;
-+ struct ts_config * (*init)(const void *, unsigned int, gfp_t);
-+ unsigned int (*find)(struct ts_config *,
-+ struct ts_state *);
-+ void (*destroy)(struct ts_config *);
-+ void * (*get_pattern)(struct ts_config *);
-+ unsigned int (*get_pattern_len)(struct ts_config *);
-+ struct module *owner;
-+ struct list_head list;
-+};
-+
-+/**
-+ * struct ts_config - search configuration
-+ * @ops: operations of chosen algorithm
-+ * @get_next_block: callback to fetch the next block to search in
-+ * @finish: callback to finalize a search
-+ */
-+struct ts_config
-+{
-+ struct ts_ops *ops;
-+
-+ /**
-+ * get_next_block - fetch next block of data
-+ * @consumed: number of bytes consumed by the caller
-+ * @dst: destination buffer
-+ * @conf: search configuration
-+ * @state: search state
-+ *
-+ * Called repeatedly until 0 is returned. Must assign the
-+ * head of the next block of data to &*dst and return the length
-+ * of the block or 0 if at the end. consumed == 0 indicates
-+ * a new search. May store/read persistant values in state->cb.
-+ */
-+ unsigned int (*get_next_block)(unsigned int consumed,
-+ const u8 **dst,
-+ struct ts_config *conf,
-+ struct ts_state *state);
-+
-+ /**
-+ * finish - finalize/clean a series of get_next_block() calls
-+ * @conf: search configuration
-+ * @state: search state
-+ *
-+ * Called after the last use of get_next_block(), may be used
-+ * to cleanup any leftovers.
-+ */
-+ void (*finish)(struct ts_config *conf,
-+ struct ts_state *state);
-+};
-+
-+/**
-+ * textsearch_next - continue searching for a pattern
-+ * @conf: search configuration
-+ * @state: search state
-+ *
-+ * Continues a search looking for more occurrences of the pattern.
-+ * textsearch_find() must be called to find the first occurrence
-+ * in order to reset the state.
-+ *
-+ * Returns the position of the next occurrence of the pattern or
-+ * UINT_MAX if not match was found.
-+ */
-+static inline unsigned int textsearch_next(struct ts_config *conf,
-+ struct ts_state *state)
-+{
-+ unsigned int ret = conf->ops->find(conf, state);
-+
-+ if (conf->finish)
-+ conf->finish(conf, state);
-+
-+ return ret;
-+}
-+
-+/**
-+ * textsearch_find - start searching for a pattern
-+ * @conf: search configuration
-+ * @state: search state
-+ *
-+ * Returns the position of first occurrence of the pattern or
-+ * UINT_MAX if no match was found.
-+ */
-+static inline unsigned int textsearch_find(struct ts_config *conf,
-+ struct ts_state *state)
-+{
-+ state->offset = 0;
-+ return textsearch_next(conf, state);
-+}
-+
-+/**
-+ * textsearch_get_pattern - return head of the pattern
-+ * @conf: search configuration
-+ */
-+static inline void *textsearch_get_pattern(struct ts_config *conf)
-+{
-+ return conf->ops->get_pattern(conf);
-+}
-+
-+/**
-+ * textsearch_get_pattern_len - return length of the pattern
-+ * @conf: search configuration
-+ */
-+static inline unsigned int textsearch_get_pattern_len(struct ts_config *conf)
-+{
-+ return conf->ops->get_pattern_len(conf);
-+}
-+
-+extern int textsearch_register(struct ts_ops *);
-+extern int textsearch_unregister(struct ts_ops *);
-+extern struct ts_config *textsearch_prepare(const char *, const void *,
-+ unsigned int, gfp_t, int);
-+extern void textsearch_destroy(struct ts_config *conf);
-+extern unsigned int textsearch_find_continuous(struct ts_config *,
-+ struct ts_state *,
-+ const void *, unsigned int);
-+
-+
-+#define TS_PRIV_ALIGNTO 8
-+#define TS_PRIV_ALIGN(len) (((len) + TS_PRIV_ALIGNTO-1) & ~(TS_PRIV_ALIGNTO-1))
-+
-+static inline struct ts_config *alloc_ts_config(size_t payload,
-+ gfp_t gfp_mask)
-+{
-+ struct ts_config *conf;
-+
-+ conf = kmalloc(TS_PRIV_ALIGN(sizeof(*conf)) + payload, gfp_mask);
-+ if (conf == NULL)
-+ return ERR_PTR(-ENOMEM);
-+
-+ memset(conf, 0, TS_PRIV_ALIGN(sizeof(*conf)) + payload);
-+ return conf;
-+}
-+
-+static inline void *ts_config_priv(struct ts_config *conf)
-+{
-+ return ((u8 *) conf + TS_PRIV_ALIGN(sizeof(struct ts_config)));
-+}
-+
-+#endif /* __KERNEL__ */
-+
-+#endif
---- /dev/null
-+++ b/net/ipv4/netfilter/textsearch/ts_bm.c
-@@ -0,0 +1,190 @@
-+/*
-+ * lib/ts_bm.c Boyer-Moore text search implementation
-+ *
-+ * This program is free software; you can redistribute it and/or
-+ * modify it under the terms of the GNU General Public License
-+ * as published by the Free Software Foundation; either version
-+ * 2 of the License, or (at your option) any later version.
-+ *
-+ * Authors: Pablo Neira Ayuso <pablo@eurodev.net>
-+ *
-+ * ==========================================================================
-+ *
-+ * Implements Boyer-Moore string matching algorithm:
-+ *
-+ * [1] A Fast String Searching Algorithm, R.S. Boyer and Moore.
-+ * Communications of the Association for Computing Machinery,
-+ * 20(10), 1977, pp. 762-772.
-+ * http://www.cs.utexas.edu/users/moore/publications/fstrpos.pdf
-+ *
-+ * [2] Handbook of Exact String Matching Algorithms, Thierry Lecroq, 2004
-+ * http://www-igm.univ-mlv.fr/~lecroq/string/string.pdf
-+ *
-+ * Note: Since Boyer-Moore (BM) performs searches for matchings from right
-+ * to left, it's still possible that a matching could be spread over
-+ * multiple blocks, in that case this algorithm won't find any coincidence.
-+ *
-+ * If you're willing to ensure that such thing won't ever happen, use the
-+ * Knuth-Pratt-Morris (KMP) implementation instead. In conclusion, choose
-+ * the proper string search algorithm depending on your setting.
-+ *
-+ * Say you're using the textsearch infrastructure for filtering, NIDS or
-+ * any similar security focused purpose, then go KMP. Otherwise, if you
-+ * really care about performance, say you're classifying packets to apply
-+ * Quality of Service (QoS) policies, and you don't mind about possible
-+ * matchings spread over multiple fragments, then go BM.
-+ */
-+
-+#include <linux/config.h>
-+#include <linux/kernel.h>
-+#include <linux/module.h>
-+#include <linux/types.h>
-+#include <linux/string.h>
-+#include "textsearch.h"
-+
-+/* Alphabet size, use ASCII */
-+#define ASIZE 256
-+
-+#if 0
-+#define DEBUGP printk
-+#else
-+#define DEBUGP(args, format...)
-+#endif
-+
-+struct ts_bm
-+{
-+ u8 * pattern;
-+ unsigned int patlen;
-+ unsigned int bad_shift[ASIZE];
-+ unsigned int good_shift[0];
-+};
-+
-+static unsigned int bm_find(struct ts_config *conf, struct ts_state *state)
-+{
-+ struct ts_bm *bm = ts_config_priv(conf);
-+ unsigned int i, text_len, consumed = state->offset;
-+ const u8 *text;
-+ int shift = bm->patlen, bs;
-+
-+ for (;;) {
-+ text_len = conf->get_next_block(consumed, &text, conf, state);
-+
-+ if (unlikely(text_len == 0))
-+ break;
-+
-+ while (shift < text_len) {
-+ DEBUGP("Searching in position %d (%c)\n",
-+ shift, text[shift]);
-+ for (i = 0; i < bm->patlen; i++)
-+ if (text[shift-i] != bm->pattern[bm->patlen-1-i])
-+ goto next;
-+
-+ /* London calling... */
-+ DEBUGP("found!\n");
-+ return consumed += (shift-(bm->patlen-1));
-+
-+next: bs = bm->bad_shift[text[shift-i]];
-+
-+ /* Now jumping to... */
-+ shift = max_t(int, shift-i+bs, shift+bm->good_shift[i]);
-+ }
-+ consumed += text_len;
-+ }
-+
-+ return UINT_MAX;
-+}
-+
-+static int subpattern(u8 *pattern, int i, int j, int g)
-+{
-+ int x = i+g-1, y = j+g-1, ret = 0;
-+
-+ while(pattern[x--] == pattern[y--]) {
-+ if (y < 0) {
-+ ret = 1;
-+ break;
-+ }
-+ if (--g == 0) {
-+ ret = pattern[i-1] != pattern[j-1];
-+ break;
-+ }
-+ }
-+
-+ return ret;
-+}
-+
-+static void bm_compute_prefix_tbl(struct ts_bm *bm, const u8 *pattern,
-+ unsigned int len)
-+{
-+ int i, j, g;
-+
-+ for (i = 0; i < ASIZE; i++)
-+ bm->bad_shift[i] = len;
-+ for (i = 0; i < len - 1; i++)
-+ bm->bad_shift[pattern[i]] = len - 1 - i;
-+
-+ /* Compute the good shift array, used to match reocurrences
-+ * of a subpattern */
-+ bm->good_shift[0] = 1;
-+ for (i = 1; i < bm->patlen; i++)
-+ bm->good_shift[i] = bm->patlen;
-+ for (i = bm->patlen-1, g = 1; i > 0; g++, i--) {
-+ for (j = i-1; j >= 1-g ; j--)
-+ if (subpattern(bm->pattern, i, j, g)) {
-+ bm->good_shift[g] = bm->patlen-j-g;
-+ break;
-+ }
-+ }
-+}
-+
-+static struct ts_config *bm_init(const void *pattern, unsigned int len,
-+ gfp_t gfp_mask)
-+{
-+ struct ts_config *conf;
-+ struct ts_bm *bm;
-+ unsigned int prefix_tbl_len = len * sizeof(unsigned int);
-+ size_t priv_size = sizeof(*bm) + len + prefix_tbl_len;
-+
-+ conf = alloc_ts_config(priv_size, gfp_mask);
-+ if (IS_ERR(conf))
-+ return conf;
-+
-+ bm = ts_config_priv(conf);
-+ bm->patlen = len;
-+ bm->pattern = (u8 *) bm->good_shift + prefix_tbl_len;
-+ bm_compute_prefix_tbl(bm, pattern, len);
-+ memcpy(bm->pattern, pattern, len);
-+
-+ return conf;
-+}
-+
-+static void *bm_get_pattern(struct ts_config *conf)
-+{
-+ struct ts_bm *bm = ts_config_priv(conf);
-+ return bm->pattern;
-+}
-+
-+static unsigned int bm_get_pattern_len(struct ts_config *conf)
-+{
-+ struct ts_bm *bm = ts_config_priv(conf);
-+ return bm->patlen;
-+}
-+
-+static struct ts_ops bm_ops = {
-+ .name = "bm",
-+ .find = bm_find,
-+ .init = bm_init,
-+ .get_pattern = bm_get_pattern,
-+ .get_pattern_len = bm_get_pattern_len,
-+ .owner = THIS_MODULE,
-+ .list = LIST_HEAD_INIT(bm_ops.list)
-+};
-+
-+static int __init init_bm(void)
-+{
-+ return textsearch_register(&bm_ops);
-+}
-+
-+static void __exit exit_bm(void)
-+{
-+ textsearch_unregister(&bm_ops);
-+}
---- /dev/null
-+++ b/net/ipv4/netfilter/textsearch/ts_kmp.c
-@@ -0,0 +1,141 @@
-+/*
-+ * lib/ts_kmp.c Knuth-Morris-Pratt text search implementation
-+ *
-+ * This program is free software; you can redistribute it and/or
-+ * modify it under the terms of the GNU General Public License
-+ * as published by the Free Software Foundation; either version
-+ * 2 of the License, or (at your option) any later version.
-+ *
-+ * Authors: Thomas Graf <tgraf@suug.ch>
-+ *
-+ * ==========================================================================
-+ *
-+ * Implements a linear-time string-matching algorithm due to Knuth,
-+ * Morris, and Pratt [1]. Their algorithm avoids the explicit
-+ * computation of the transition function DELTA altogether. Its
-+ * matching time is O(n), for n being length(text), using just an
-+ * auxiliary function PI[1..m], for m being length(pattern),
-+ * precomputed from the pattern in time O(m). The array PI allows
-+ * the transition function DELTA to be computed efficiently
-+ * "on the fly" as needed. Roughly speaking, for any state
-+ * "q" = 0,1,...,m and any character "a" in SIGMA, the value
-+ * PI["q"] contains the information that is independent of "a" and
-+ * is needed to compute DELTA("q", "a") [2]. Since the array PI
-+ * has only m entries, whereas DELTA has O(m|SIGMA|) entries, we
-+ * save a factor of |SIGMA| in the preprocessing time by computing
-+ * PI rather than DELTA.
-+ *
-+ * [1] Cormen, Leiserson, Rivest, Stein
-+ * Introdcution to Algorithms, 2nd Edition, MIT Press
-+ * [2] See finite automation theory
-+ */
-+
-+#include <linux/config.h>
-+#include <linux/module.h>
-+#include <linux/types.h>
-+#include <linux/string.h>
-+#include "textsearch.h"
-+
-+struct ts_kmp
-+{
-+ u8 * pattern;
-+ unsigned int pattern_len;
-+ unsigned int prefix_tbl[0];
-+};
-+
-+static unsigned int kmp_find(struct ts_config *conf, struct ts_state *state)
-+{
-+ struct ts_kmp *kmp = ts_config_priv(conf);
-+ unsigned int i, q = 0, text_len, consumed = state->offset;
-+ const u8 *text;
-+
-+ for (;;) {
-+ text_len = conf->get_next_block(consumed, &text, conf, state);
-+
-+ if (unlikely(text_len == 0))
-+ break;
-+
-+ for (i = 0; i < text_len; i++) {
-+ while (q > 0 && kmp->pattern[q] != text[i])
-+ q = kmp->prefix_tbl[q - 1];
-+ if (kmp->pattern[q] == text[i])
-+ q++;
-+ if (unlikely(q == kmp->pattern_len)) {
-+ state->offset = consumed + i + 1;
-+ return state->offset - kmp->pattern_len;
-+ }
-+ }
-+
-+ consumed += text_len;
-+ }
-+
-+ return UINT_MAX;
-+}
-+
-+static inline void kmp_compute_prefix_tbl(const u8 *pattern, unsigned int len,
-+ unsigned int *prefix_tbl)
-+{
-+ unsigned int k, q;
-+
-+ for (k = 0, q = 1; q < len; q++) {
-+ while (k > 0 && pattern[k] != pattern[q])
-+ k = prefix_tbl[k-1];
-+ if (pattern[k] == pattern[q])
-+ k++;
-+ prefix_tbl[q] = k;
-+ }
-+}
-+
-+static struct ts_config *kmp_init(const void *pattern, unsigned int len,
-+ gfp_t gfp_mask)
-+{
-+ struct ts_config *conf;
-+ struct ts_kmp *kmp;
-+ unsigned int prefix_tbl_len = len * sizeof(unsigned int);
-+ size_t priv_size = sizeof(*kmp) + len + prefix_tbl_len;
-+
-+ conf = alloc_ts_config(priv_size, gfp_mask);
-+ if (IS_ERR(conf))
-+ return conf;
-+
-+ kmp = ts_config_priv(conf);
-+ kmp->pattern_len = len;
-+ kmp_compute_prefix_tbl(pattern, len, kmp->prefix_tbl);
-+ kmp->pattern = (u8 *) kmp->prefix_tbl + prefix_tbl_len;
-+ memcpy(kmp->pattern, pattern, len);
-+
-+ return conf;
-+}
-+
-+static void *kmp_get_pattern(struct ts_config *conf)
-+{
-+ struct ts_kmp *kmp = ts_config_priv(conf);
-+ return kmp->pattern;
-+}
-+
-+static unsigned int kmp_get_pattern_len(struct ts_config *conf)
-+{
-+ struct ts_kmp *kmp = ts_config_priv(conf);
-+ return kmp->pattern_len;
-+}
-+
-+static struct ts_ops kmp_ops = {
-+ .name = "kmp",
-+ .find = kmp_find,
-+ .init = kmp_init,
-+ .get_pattern = kmp_get_pattern,
-+ .get_pattern_len = kmp_get_pattern_len,
-+ .owner = THIS_MODULE,
-+ .list = LIST_HEAD_INIT(kmp_ops.list)
-+};
-+
-+static int __init init_kmp(void)
-+{
-+ return textsearch_register(&kmp_ops);
-+}
-+
-+static void __exit exit_kmp(void)
-+{
-+ textsearch_unregister(&kmp_ops);
-+}
-+
projects / openwrt / svn-archive / archive.git / blobdiff