cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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em_text.c (3532B)

      1// SPDX-License-Identifier: GPL-2.0-or-later
      2/*
      3 * net/sched/em_text.c	Textsearch ematch
      4 *
      5 * Authors:	Thomas Graf <tgraf@suug.ch>
      6 */
      7
      8#include <linux/slab.h>
      9#include <linux/module.h>
     10#include <linux/types.h>
     11#include <linux/kernel.h>
     12#include <linux/string.h>
     13#include <linux/skbuff.h>
     14#include <linux/textsearch.h>
     15#include <linux/tc_ematch/tc_em_text.h>
     16#include <net/pkt_cls.h>
     17
     18struct text_match {
     19	u16			from_offset;
     20	u16			to_offset;
     21	u8			from_layer;
     22	u8			to_layer;
     23	struct ts_config	*config;
     24};
     25
     26#define EM_TEXT_PRIV(m) ((struct text_match *) (m)->data)
     27
     28static int em_text_match(struct sk_buff *skb, struct tcf_ematch *m,
     29			 struct tcf_pkt_info *info)
     30{
     31	struct text_match *tm = EM_TEXT_PRIV(m);
     32	int from, to;
     33
     34	from = tcf_get_base_ptr(skb, tm->from_layer) - skb->data;
     35	from += tm->from_offset;
     36
     37	to = tcf_get_base_ptr(skb, tm->to_layer) - skb->data;
     38	to += tm->to_offset;
     39
     40	return skb_find_text(skb, from, to, tm->config) != UINT_MAX;
     41}
     42
     43static int em_text_change(struct net *net, void *data, int len,
     44			  struct tcf_ematch *m)
     45{
     46	struct text_match *tm;
     47	struct tcf_em_text *conf = data;
     48	struct ts_config *ts_conf;
     49	int flags = 0;
     50
     51	if (len < sizeof(*conf) || len < (sizeof(*conf) + conf->pattern_len))
     52		return -EINVAL;
     53
     54	if (conf->from_layer > conf->to_layer)
     55		return -EINVAL;
     56
     57	if (conf->from_layer == conf->to_layer &&
     58	    conf->from_offset > conf->to_offset)
     59		return -EINVAL;
     60
     61retry:
     62	ts_conf = textsearch_prepare(conf->algo, (u8 *) conf + sizeof(*conf),
     63				     conf->pattern_len, GFP_KERNEL, flags);
     64
     65	if (flags & TS_AUTOLOAD)
     66		rtnl_lock();
     67
     68	if (IS_ERR(ts_conf)) {
     69		if (PTR_ERR(ts_conf) == -ENOENT && !(flags & TS_AUTOLOAD)) {
     70			rtnl_unlock();
     71			flags |= TS_AUTOLOAD;
     72			goto retry;
     73		} else
     74			return PTR_ERR(ts_conf);
     75	} else if (flags & TS_AUTOLOAD) {
     76		textsearch_destroy(ts_conf);
     77		return -EAGAIN;
     78	}
     79
     80	tm = kmalloc(sizeof(*tm), GFP_KERNEL);
     81	if (tm == NULL) {
     82		textsearch_destroy(ts_conf);
     83		return -ENOBUFS;
     84	}
     85
     86	tm->from_offset = conf->from_offset;
     87	tm->to_offset   = conf->to_offset;
     88	tm->from_layer  = conf->from_layer;
     89	tm->to_layer    = conf->to_layer;
     90	tm->config      = ts_conf;
     91
     92	m->datalen = sizeof(*tm);
     93	m->data = (unsigned long) tm;
     94
     95	return 0;
     96}
     97
     98static void em_text_destroy(struct tcf_ematch *m)
     99{
    100	if (EM_TEXT_PRIV(m) && EM_TEXT_PRIV(m)->config)
    101		textsearch_destroy(EM_TEXT_PRIV(m)->config);
    102}
    103
    104static int em_text_dump(struct sk_buff *skb, struct tcf_ematch *m)
    105{
    106	struct text_match *tm = EM_TEXT_PRIV(m);
    107	struct tcf_em_text conf;
    108
    109	strncpy(conf.algo, tm->config->ops->name, sizeof(conf.algo) - 1);
    110	conf.from_offset = tm->from_offset;
    111	conf.to_offset = tm->to_offset;
    112	conf.from_layer = tm->from_layer;
    113	conf.to_layer = tm->to_layer;
    114	conf.pattern_len = textsearch_get_pattern_len(tm->config);
    115	conf.pad = 0;
    116
    117	if (nla_put_nohdr(skb, sizeof(conf), &conf) < 0)
    118		goto nla_put_failure;
    119	if (nla_append(skb, conf.pattern_len,
    120		       textsearch_get_pattern(tm->config)) < 0)
    121		goto nla_put_failure;
    122	return 0;
    123
    124nla_put_failure:
    125	return -1;
    126}
    127
    128static struct tcf_ematch_ops em_text_ops = {
    129	.kind	  = TCF_EM_TEXT,
    130	.change	  = em_text_change,
    131	.match	  = em_text_match,
    132	.destroy  = em_text_destroy,
    133	.dump	  = em_text_dump,
    134	.owner	  = THIS_MODULE,
    135	.link	  = LIST_HEAD_INIT(em_text_ops.link)
    136};
    137
    138static int __init init_em_text(void)
    139{
    140	return tcf_em_register(&em_text_ops);
    141}
    142
    143static void __exit exit_em_text(void)
    144{
    145	tcf_em_unregister(&em_text_ops);
    146}
    147
    148MODULE_LICENSE("GPL");
    149
    150module_init(init_em_text);
    151module_exit(exit_em_text);
    152
    153MODULE_ALIAS_TCF_EMATCH(TCF_EM_TEXT);