From 4fdb3bb723db469717c6d38fda667d8b0fa86ebd Mon Sep 17 00:00:00 2001 From: Harald Welte Date: Tue, 9 Aug 2005 19:40:55 -0700 Subject: [NETLINK]: Add properly module refcounting for kernel netlink sockets. - Remove bogus code for compiling netlink as module - Add module refcounting support for modules implementing a netlink protocol - Add support for autoloading modules that implement a netlink protocol as soon as someone opens a socket for that protocol Signed-off-by: Harald Welte Signed-off-by: David S. Miller --- lib/kobject_uevent.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index 8e49d21057..88f4d746aa 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -153,7 +153,8 @@ EXPORT_SYMBOL_GPL(kobject_uevent_atomic); static int __init kobject_uevent_init(void) { - uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, NULL); + uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, NULL, + THIS_MODULE); if (!uevent_sock) { printk(KERN_ERR -- cgit v1.2.2 From 43e943c32b9213b5d25407b281c94aaa474fd9a6 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Sun, 14 Aug 2005 19:25:47 -0700 Subject: [NETLINK]: Fix missing dst_groups initializations in netlink_broadcast users netlink_broadcast users must initialize NETLINK_CB(skb).dst_groups to the destination group mask for netlink_recvmsg. Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- lib/kobject_uevent.c | 1 + 1 file changed, 1 insertion(+) (limited to 'lib') diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index 88f4d746aa..bc000619f4 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -93,6 +93,7 @@ static int send_uevent(const char *signal, const char *obj, } } + NETLINK_CB(skb).dst_groups = 1; return netlink_broadcast(uevent_sock, skb, 0, 1, gfp_mask); } -- cgit v1.2.2 From ac6d439d2097b72ea0cbc2322ce1263a38bc1fd0 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Sun, 14 Aug 2005 19:29:52 -0700 Subject: [NETLINK]: Convert netlink users to use group numbers instead of bitmasks Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- lib/kobject_uevent.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index bc000619f4..1ebd735d64 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -93,7 +93,7 @@ static int send_uevent(const char *signal, const char *obj, } } - NETLINK_CB(skb).dst_groups = 1; + NETLINK_CB(skb).dst_group = 1; return netlink_broadcast(uevent_sock, skb, 0, 1, gfp_mask); } -- cgit v1.2.2 From 066286071d3542243baa68166acb779187c848b3 Mon Sep 17 00:00:00 2001 From: Patrick McHardy Date: Mon, 15 Aug 2005 12:33:26 -0700 Subject: [NETLINK]: Add "groups" argument to netlink_kernel_create Signed-off-by: Patrick McHardy Signed-off-by: David S. Miller --- lib/kobject_uevent.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'lib') diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c index 1ebd735d64..04ca4429dd 100644 --- a/lib/kobject_uevent.c +++ b/lib/kobject_uevent.c @@ -154,7 +154,7 @@ EXPORT_SYMBOL_GPL(kobject_uevent_atomic); static int __init kobject_uevent_init(void) { - uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, NULL, + uevent_sock = netlink_kernel_create(NETLINK_KOBJECT_UEVENT, 1, NULL, THIS_MODULE); if (!uevent_sock) { -- cgit v1.2.2 From 8082e4ed0a61da347f1c7f210493c4e9e55c8cd0 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Thu, 25 Aug 2005 16:12:22 -0700 Subject: [LIB]: Boyer-Moore extension for textsearch infrastructure strike #2 Attached the implementation of the Boyer-Moore string search algorithm for the new textsearch infrastructure. I've added as well a note about the limitations that this approach presents, as Thomas has remarked. Signed-off-by: Pablo Neira Ayuso Signed-off-by: David S. Miller --- lib/Kconfig | 10 ++++ lib/Makefile | 1 + lib/ts_bm.c | 185 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 196 insertions(+) create mode 100644 lib/ts_bm.c (limited to 'lib') diff --git a/lib/Kconfig b/lib/Kconfig index eeb429a521..b62f685f79 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -72,6 +72,16 @@ config TEXTSEARCH config TEXTSEARCH_KMP tristate +config TEXTSEARCH_BM + depends on TEXTSEARCH + tristate "Boyer-Moore" + help + Say Y here if you want to be able to search text using the + Boyer-Moore textsearch algorithm. + + To compile this code as a module, choose M here: the + module will be called ts_bm. + config TEXTSEARCH_FSM tristate diff --git a/lib/Makefile b/lib/Makefile index f28d903130..52f83380f7 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -38,6 +38,7 @@ obj-$(CONFIG_REED_SOLOMON) += reed_solomon/ obj-$(CONFIG_TEXTSEARCH) += textsearch.o obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o +obj-$(CONFIG_TEXTSEARCH_BM) += ts_bm.o obj-$(CONFIG_TEXTSEARCH_FSM) += ts_fsm.o hostprogs-y := gen_crc32table diff --git a/lib/ts_bm.c b/lib/ts_bm.c new file mode 100644 index 0000000000..2cc79112ec --- /dev/null +++ b/lib/ts_bm.c @@ -0,0 +1,185 @@ +/* + * 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 + * + * ========================================================================== + * + * 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 +#include +#include +#include +#include +#include + +/* 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 void compute_prefix_tbl(struct ts_bm *bm, const u8 *pattern, + unsigned int len) +{ + int i, j, ended, l[ASIZE]; + + 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 */ + for (i = 1; i < bm->patlen; i++) { + for (j = 0; j < bm->patlen && bm->pattern[bm->patlen - 1 - j] + == bm->pattern[bm->patlen - 1 - i - j]; j++); + l[i] = j; + } + + bm->good_shift[0] = 1; + for (i = 1; i < bm->patlen; i++) + bm->good_shift[i] = bm->patlen; + for (i = bm->patlen - 1; i > 0; i--) + bm->good_shift[l[i]] = i; + ended = 0; + for (i = 0; i < bm->patlen; i++) { + if (l[i] == bm->patlen - 1 - i) + ended = i; + if (ended) + bm->good_shift[i] = ended; + } +} + +static struct ts_config *bm_init(const void *pattern, unsigned int len, + int 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; + 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); +} + +MODULE_LICENSE("GPL"); + +module_init(init_bm); +module_exit(exit_bm); -- cgit v1.2.2 From 29cb9f9c5502f6218cd3ea574efe46a5e55522d2 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Thu, 25 Aug 2005 16:23:11 -0700 Subject: [LIB]: Make TEXTSEARCH_BM plain tristate like the others And select it when the relevant modules are enabled. Signed-off-by: David S. Miller --- lib/Kconfig | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) (limited to 'lib') diff --git a/lib/Kconfig b/lib/Kconfig index b62f685f79..e43197efeb 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -73,14 +73,7 @@ config TEXTSEARCH_KMP tristate config TEXTSEARCH_BM - depends on TEXTSEARCH - tristate "Boyer-Moore" - help - Say Y here if you want to be able to search text using the - Boyer-Moore textsearch algorithm. - - To compile this code as a module, choose M here: the - module will be called ts_bm. + tristate config TEXTSEARCH_FSM tristate -- cgit v1.2.2