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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/sched/em_cmp.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'net/sched/em_cmp.c')
-rw-r--r--net/sched/em_cmp.c101
1 files changed, 101 insertions, 0 deletions
diff --git a/net/sched/em_cmp.c b/net/sched/em_cmp.c
new file mode 100644
index 000000000000..bf1f00f8b1bf
--- /dev/null
+++ b/net/sched/em_cmp.c
@@ -0,0 +1,101 @@
1/*
2 * net/sched/em_cmp.c Simple packet data comparison ematch
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation; either version
7 * 2 of the License, or (at your option) any later version.
8 *
9 * Authors: Thomas Graf <tgraf@suug.ch>
10 */
11
12#include <linux/config.h>
13#include <linux/module.h>
14#include <linux/types.h>
15#include <linux/kernel.h>
16#include <linux/skbuff.h>
17#include <linux/tc_ematch/tc_em_cmp.h>
18#include <net/pkt_cls.h>
19
20static inline int cmp_needs_transformation(struct tcf_em_cmp *cmp)
21{
22 return unlikely(cmp->flags & TCF_EM_CMP_TRANS);
23}
24
25static int em_cmp_match(struct sk_buff *skb, struct tcf_ematch *em,
26 struct tcf_pkt_info *info)
27{
28 struct tcf_em_cmp *cmp = (struct tcf_em_cmp *) em->data;
29 unsigned char *ptr = tcf_get_base_ptr(skb, cmp->layer) + cmp->off;
30 u32 val = 0;
31
32 if (!tcf_valid_offset(skb, ptr, cmp->align))
33 return 0;
34
35 switch (cmp->align) {
36 case TCF_EM_ALIGN_U8:
37 val = *ptr;
38 break;
39
40 case TCF_EM_ALIGN_U16:
41 val = *ptr << 8;
42 val |= *(ptr+1);
43
44 if (cmp_needs_transformation(cmp))
45 val = be16_to_cpu(val);
46 break;
47
48 case TCF_EM_ALIGN_U32:
49 /* Worth checking boundries? The branching seems
50 * to get worse. Visit again. */
51 val = *ptr << 24;
52 val |= *(ptr+1) << 16;
53 val |= *(ptr+2) << 8;
54 val |= *(ptr+3);
55
56 if (cmp_needs_transformation(cmp))
57 val = be32_to_cpu(val);
58 break;
59
60 default:
61 return 0;
62 }
63
64 if (cmp->mask)
65 val &= cmp->mask;
66
67 switch (cmp->opnd) {
68 case TCF_EM_OPND_EQ:
69 return val == cmp->val;
70 case TCF_EM_OPND_LT:
71 return val < cmp->val;
72 case TCF_EM_OPND_GT:
73 return val > cmp->val;
74 }
75
76 return 0;
77}
78
79static struct tcf_ematch_ops em_cmp_ops = {
80 .kind = TCF_EM_CMP,
81 .datalen = sizeof(struct tcf_em_cmp),
82 .match = em_cmp_match,
83 .owner = THIS_MODULE,
84 .link = LIST_HEAD_INIT(em_cmp_ops.link)
85};
86
87static int __init init_em_cmp(void)
88{
89 return tcf_em_register(&em_cmp_ops);
90}
91
92static void __exit exit_em_cmp(void)
93{
94 tcf_em_unregister(&em_cmp_ops);
95}
96
97MODULE_LICENSE("GPL");
98
99module_init(init_em_cmp);
100module_exit(exit_em_cmp);
101