158 lines
3.7 KiB
C
158 lines
3.7 KiB
C
/*
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* net/sched/em_text.c Textsearch ematch
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* Authors: Thomas Graf <tgraf@suug.ch>
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*/
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#include <linux/slab.h>
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#include <linux/module.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/string.h>
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#include <linux/skbuff.h>
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#include <linux/textsearch.h>
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#include <linux/tc_ematch/tc_em_text.h>
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#include <net/pkt_cls.h>
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struct text_match {
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u16 from_offset;
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u16 to_offset;
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u8 from_layer;
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u8 to_layer;
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struct ts_config *config;
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};
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#define EM_TEXT_PRIV(m) ((struct text_match *) (m)->data)
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static int em_text_match(struct sk_buff *skb, struct tcf_ematch *m,
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struct tcf_pkt_info *info)
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{
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struct text_match *tm = EM_TEXT_PRIV(m);
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int from, to;
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from = tcf_get_base_ptr(skb, tm->from_layer) - skb->data;
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from += tm->from_offset;
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to = tcf_get_base_ptr(skb, tm->to_layer) - skb->data;
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to += tm->to_offset;
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return skb_find_text(skb, from, to, tm->config) != UINT_MAX;
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}
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static int em_text_change(struct net *net, void *data, int len,
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struct tcf_ematch *m)
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{
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struct text_match *tm;
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struct tcf_em_text *conf = data;
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struct ts_config *ts_conf;
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int flags = 0;
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if (len < sizeof(*conf) || len < (sizeof(*conf) + conf->pattern_len))
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return -EINVAL;
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if (conf->from_layer > conf->to_layer)
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return -EINVAL;
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if (conf->from_layer == conf->to_layer &&
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conf->from_offset > conf->to_offset)
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return -EINVAL;
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retry:
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ts_conf = textsearch_prepare(conf->algo, (u8 *) conf + sizeof(*conf),
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conf->pattern_len, GFP_KERNEL, flags);
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if (flags & TS_AUTOLOAD)
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rtnl_lock();
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if (IS_ERR(ts_conf)) {
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if (PTR_ERR(ts_conf) == -ENOENT && !(flags & TS_AUTOLOAD)) {
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rtnl_unlock();
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flags |= TS_AUTOLOAD;
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goto retry;
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} else
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return PTR_ERR(ts_conf);
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} else if (flags & TS_AUTOLOAD) {
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textsearch_destroy(ts_conf);
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return -EAGAIN;
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}
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tm = kmalloc(sizeof(*tm), GFP_KERNEL);
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if (tm == NULL) {
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textsearch_destroy(ts_conf);
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return -ENOBUFS;
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}
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tm->from_offset = conf->from_offset;
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tm->to_offset = conf->to_offset;
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tm->from_layer = conf->from_layer;
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tm->to_layer = conf->to_layer;
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tm->config = ts_conf;
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m->datalen = sizeof(*tm);
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m->data = (unsigned long) tm;
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return 0;
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}
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static void em_text_destroy(struct tcf_ematch *m)
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{
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if (EM_TEXT_PRIV(m) && EM_TEXT_PRIV(m)->config)
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textsearch_destroy(EM_TEXT_PRIV(m)->config);
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}
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static int em_text_dump(struct sk_buff *skb, struct tcf_ematch *m)
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{
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struct text_match *tm = EM_TEXT_PRIV(m);
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struct tcf_em_text conf;
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strncpy(conf.algo, tm->config->ops->name, sizeof(conf.algo) - 1);
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conf.from_offset = tm->from_offset;
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conf.to_offset = tm->to_offset;
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conf.from_layer = tm->from_layer;
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conf.to_layer = tm->to_layer;
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conf.pattern_len = textsearch_get_pattern_len(tm->config);
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conf.pad = 0;
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if (nla_put_nohdr(skb, sizeof(conf), &conf) < 0)
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goto nla_put_failure;
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if (nla_append(skb, conf.pattern_len,
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textsearch_get_pattern(tm->config)) < 0)
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goto nla_put_failure;
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return 0;
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nla_put_failure:
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return -1;
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}
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static struct tcf_ematch_ops em_text_ops = {
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.kind = TCF_EM_TEXT,
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.change = em_text_change,
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.match = em_text_match,
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.destroy = em_text_destroy,
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.dump = em_text_dump,
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.owner = THIS_MODULE,
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.link = LIST_HEAD_INIT(em_text_ops.link)
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};
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static int __init init_em_text(void)
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{
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return tcf_em_register(&em_text_ops);
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}
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static void __exit exit_em_text(void)
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{
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tcf_em_unregister(&em_text_ops);
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}
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MODULE_LICENSE("GPL");
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module_init(init_em_text);
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module_exit(exit_em_text);
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MODULE_ALIAS_TCF_EMATCH(TCF_EM_TEXT);
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