96 строки
1.9 KiB
C
96 строки
1.9 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* net/sched/em_cmp.c Simple packet data comparison ematch
|
|
*
|
|
* Authors: Thomas Graf <tgraf@suug.ch>
|
|
*/
|
|
|
|
#include <linux/module.h>
|
|
#include <linux/types.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/skbuff.h>
|
|
#include <linux/tc_ematch/tc_em_cmp.h>
|
|
#include <asm/unaligned.h>
|
|
#include <net/pkt_cls.h>
|
|
|
|
static inline int cmp_needs_transformation(struct tcf_em_cmp *cmp)
|
|
{
|
|
return unlikely(cmp->flags & TCF_EM_CMP_TRANS);
|
|
}
|
|
|
|
static int em_cmp_match(struct sk_buff *skb, struct tcf_ematch *em,
|
|
struct tcf_pkt_info *info)
|
|
{
|
|
struct tcf_em_cmp *cmp = (struct tcf_em_cmp *) em->data;
|
|
unsigned char *ptr = tcf_get_base_ptr(skb, cmp->layer) + cmp->off;
|
|
u32 val = 0;
|
|
|
|
if (!tcf_valid_offset(skb, ptr, cmp->align))
|
|
return 0;
|
|
|
|
switch (cmp->align) {
|
|
case TCF_EM_ALIGN_U8:
|
|
val = *ptr;
|
|
break;
|
|
|
|
case TCF_EM_ALIGN_U16:
|
|
val = get_unaligned_be16(ptr);
|
|
|
|
if (cmp_needs_transformation(cmp))
|
|
val = be16_to_cpu(val);
|
|
break;
|
|
|
|
case TCF_EM_ALIGN_U32:
|
|
/* Worth checking boundries? The branching seems
|
|
* to get worse. Visit again.
|
|
*/
|
|
val = get_unaligned_be32(ptr);
|
|
|
|
if (cmp_needs_transformation(cmp))
|
|
val = be32_to_cpu(val);
|
|
break;
|
|
|
|
default:
|
|
return 0;
|
|
}
|
|
|
|
if (cmp->mask)
|
|
val &= cmp->mask;
|
|
|
|
switch (cmp->opnd) {
|
|
case TCF_EM_OPND_EQ:
|
|
return val == cmp->val;
|
|
case TCF_EM_OPND_LT:
|
|
return val < cmp->val;
|
|
case TCF_EM_OPND_GT:
|
|
return val > cmp->val;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct tcf_ematch_ops em_cmp_ops = {
|
|
.kind = TCF_EM_CMP,
|
|
.datalen = sizeof(struct tcf_em_cmp),
|
|
.match = em_cmp_match,
|
|
.owner = THIS_MODULE,
|
|
.link = LIST_HEAD_INIT(em_cmp_ops.link)
|
|
};
|
|
|
|
static int __init init_em_cmp(void)
|
|
{
|
|
return tcf_em_register(&em_cmp_ops);
|
|
}
|
|
|
|
static void __exit exit_em_cmp(void)
|
|
{
|
|
tcf_em_unregister(&em_cmp_ops);
|
|
}
|
|
|
|
MODULE_LICENSE("GPL");
|
|
|
|
module_init(init_em_cmp);
|
|
module_exit(exit_em_cmp);
|
|
|
|
MODULE_ALIAS_TCF_EMATCH(TCF_EM_CMP);
|