ipv4: tcp: set unicast_sock uc_ttl to -1
[linux-3.10.git] / net / sched / em_cmp.c
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/module.h>
13 #include <linux/types.h>
14 #include <linux/kernel.h>
15 #include <linux/skbuff.h>
16 #include <linux/tc_ematch/tc_em_cmp.h>
17 #include <asm/unaligned.h>
18 #include <net/pkt_cls.h>
19
20 static inline int cmp_needs_transformation(struct tcf_em_cmp *cmp)
21 {
22         return unlikely(cmp->flags & TCF_EM_CMP_TRANS);
23 }
24
25 static 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 = get_unaligned_be16(ptr);
42
43                 if (cmp_needs_transformation(cmp))
44                         val = be16_to_cpu(val);
45                 break;
46
47         case TCF_EM_ALIGN_U32:
48                 /* Worth checking boundries? The branching seems
49                  * to get worse. Visit again.
50                  */
51                 val = get_unaligned_be32(ptr);
52
53                 if (cmp_needs_transformation(cmp))
54                         val = be32_to_cpu(val);
55                 break;
56
57         default:
58                 return 0;
59         }
60
61         if (cmp->mask)
62                 val &= cmp->mask;
63
64         switch (cmp->opnd) {
65         case TCF_EM_OPND_EQ:
66                 return val == cmp->val;
67         case TCF_EM_OPND_LT:
68                 return val < cmp->val;
69         case TCF_EM_OPND_GT:
70                 return val > cmp->val;
71         }
72
73         return 0;
74 }
75
76 static struct tcf_ematch_ops em_cmp_ops = {
77         .kind     = TCF_EM_CMP,
78         .datalen  = sizeof(struct tcf_em_cmp),
79         .match    = em_cmp_match,
80         .owner    = THIS_MODULE,
81         .link     = LIST_HEAD_INIT(em_cmp_ops.link)
82 };
83
84 static int __init init_em_cmp(void)
85 {
86         return tcf_em_register(&em_cmp_ops);
87 }
88
89 static void __exit exit_em_cmp(void)
90 {
91         tcf_em_unregister(&em_cmp_ops);
92 }
93
94 MODULE_LICENSE("GPL");
95
96 module_init(init_em_cmp);
97 module_exit(exit_em_cmp);
98
99 MODULE_ALIAS_TCF_EMATCH(TCF_EM_CMP);