/* * net/sched/em_text.c Textsearch ematch * * 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> */ #include <linux/module.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/string.h> #include <linux/skbuff.h> #include <linux/textsearch.h> #include <linux/tc_ematch/tc_em_text.h> #include <net/pkt_cls.h> struct text_match { u16 from_offset; u16 to_offset; u8 from_layer; u8 to_layer; struct ts_config *config; }; #define EM_TEXT_PRIV(m) ((struct text_match *) (m)->data) static int em_text_match(struct sk_buff *skb, struct tcf_ematch *m, struct tcf_pkt_info *info) { struct text_match *tm = EM_TEXT_PRIV(m); int from, to; struct ts_state state; from = tcf_get_base_ptr(skb, tm->from_layer) - skb->data; from += tm->from_offset; to = tcf_get_base_ptr(skb, tm->to_layer) - skb->data; to += tm->to_offset; return skb_find_text(skb, from, to, tm->config, &state) != UINT_MAX; } static int em_text_change(struct tcf_proto *tp, void *data, int len, struct tcf_ematch *m) { struct text_match *tm; struct tcf_em_text *conf = data; struct ts_config *ts_conf; int flags = 0; if (len < sizeof(*conf) || len < (sizeof(*conf) + conf->pattern_len)) return -EINVAL; if (conf->from_layer > conf->to_layer) return -EINVAL; if (conf->from_layer == conf->to_layer && conf->from_offset > conf->to_offset) return -EINVAL; retry: ts_conf = textsearch_prepare(conf->algo, (u8 *) conf + sizeof(*conf), conf->pattern_len, GFP_KERNEL, flags); if (flags & TS_AUTOLOAD) rtnl_lock(); if (IS_ERR(ts_conf)) { if (PTR_ERR(ts_conf) == -ENOENT && !(flags & TS_AUTOLOAD)) { rtnl_unlock(); flags |= TS_AUTOLOAD; goto retry; } else return PTR_ERR(ts_conf); } else if (flags & TS_AUTOLOAD) { textsearch_destroy(ts_conf); return -EAGAIN; } tm = kmalloc(sizeof(*tm), GFP_KERNEL); if (tm == NULL) { textsearch_destroy(ts_conf); return -ENOBUFS; } tm->from_offset = conf->from_offset; tm->to_offset = conf->to_offset; tm->from_layer = conf->from_layer; tm->to_layer = conf->to_layer; tm->config = ts_conf; m->datalen = sizeof(*tm); m->data = (unsigned long) tm; return 0; } static void em_text_destroy(struct tcf_proto *tp, struct tcf_ematch *m) { textsearch_destroy(EM_TEXT_PRIV(m)->config); } static int em_text_dump(struct sk_buff *skb, struct tcf_ematch *m) { struct text_match *tm = EM_TEXT_PRIV(m); struct tcf_em_text conf; strncpy(conf.algo, tm->config->ops->name, sizeof(conf.algo) - 1); conf.from_offset = tm->from_offset; conf.to_offset = tm->to_offset; conf.from_layer = tm->from_layer; conf.to_layer = tm->to_layer; conf.pattern_len = textsearch_get_pattern_len(tm->config); conf.pad = 0; RTA_PUT_NOHDR(skb, sizeof(conf), &conf); RTA_APPEND(skb, conf.pattern_len, textsearch_get_pattern(tm->config)); return 0; rtattr_failure: return -1; } static struct tcf_ematch_ops em_text_ops = { .kind = TCF_EM_TEXT, .change = em_text_change, .match = em_text_match, .destroy = em_text_destroy, .dump = em_text_dump, .owner = THIS_MODULE, .link = LIST_HEAD_INIT(em_text_ops.link) }; static int __init init_em_text(void) { return tcf_em_register(&em_text_ops); } static void __exit exit_em_text(void) { tcf_em_unregister(&em_text_ops); } MODULE_LICENSE("GPL"); module_init(init_em_text); module_exit(exit_em_text);