1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
|
// SPDX-License-Identifier: GPL-2.0-or-later
/* Structure dynamic extension infrastructure
* Copyright (C) 2004 Rusty Russell IBM Corporation
* Copyright (C) 2007 Netfilter Core Team <coreteam@netfilter.org>
* Copyright (C) 2007 USAGI/WIDE Project <http://www.linux-ipv6.org>
*/
#include <linux/kernel.h>
#include <linux/kmemleak.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/rcupdate.h>
#include <linux/slab.h>
#include <linux/skbuff.h>
#include <net/netfilter/nf_conntrack_extend.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_acct.h>
#include <net/netfilter/nf_conntrack_seqadj.h>
#include <net/netfilter/nf_conntrack_ecache.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/nf_conntrack_timestamp.h>
#include <net/netfilter/nf_conntrack_timeout.h>
#include <net/netfilter/nf_conntrack_labels.h>
#include <net/netfilter/nf_conntrack_synproxy.h>
#include <net/netfilter/nf_conntrack_act_ct.h>
#include <net/netfilter/nf_nat.h>
#define NF_CT_EXT_PREALLOC 128u /* conntrack events are on by default */
atomic_t nf_conntrack_ext_genid __read_mostly = ATOMIC_INIT(1);
static const u8 nf_ct_ext_type_len[NF_CT_EXT_NUM] = {
[NF_CT_EXT_HELPER] = sizeof(struct nf_conn_help),
#if IS_ENABLED(CONFIG_NF_NAT)
[NF_CT_EXT_NAT] = sizeof(struct nf_conn_nat),
#endif
[NF_CT_EXT_SEQADJ] = sizeof(struct nf_conn_seqadj),
[NF_CT_EXT_ACCT] = sizeof(struct nf_conn_acct),
#ifdef CONFIG_NF_CONNTRACK_EVENTS
[NF_CT_EXT_ECACHE] = sizeof(struct nf_conntrack_ecache),
#endif
#ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
[NF_CT_EXT_TSTAMP] = sizeof(struct nf_conn_tstamp),
#endif
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
[NF_CT_EXT_TIMEOUT] = sizeof(struct nf_conn_timeout),
#endif
#ifdef CONFIG_NF_CONNTRACK_LABELS
[NF_CT_EXT_LABELS] = sizeof(struct nf_conn_labels),
#endif
#if IS_ENABLED(CONFIG_NETFILTER_SYNPROXY)
[NF_CT_EXT_SYNPROXY] = sizeof(struct nf_conn_synproxy),
#endif
#if IS_ENABLED(CONFIG_NET_ACT_CT)
[NF_CT_EXT_ACT_CT] = sizeof(struct nf_conn_act_ct_ext),
#endif
};
static __always_inline unsigned int total_extension_size(void)
{
/* remember to add new extensions below */
BUILD_BUG_ON(NF_CT_EXT_NUM > 10);
return sizeof(struct nf_ct_ext) +
sizeof(struct nf_conn_help)
#if IS_ENABLED(CONFIG_NF_NAT)
+ sizeof(struct nf_conn_nat)
#endif
+ sizeof(struct nf_conn_seqadj)
+ sizeof(struct nf_conn_acct)
#ifdef CONFIG_NF_CONNTRACK_EVENTS
+ sizeof(struct nf_conntrack_ecache)
#endif
#ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
+ sizeof(struct nf_conn_tstamp)
#endif
#ifdef CONFIG_NF_CONNTRACK_TIMEOUT
+ sizeof(struct nf_conn_timeout)
#endif
#ifdef CONFIG_NF_CONNTRACK_LABELS
+ sizeof(struct nf_conn_labels)
#endif
#if IS_ENABLED(CONFIG_NETFILTER_SYNPROXY)
+ sizeof(struct nf_conn_synproxy)
#endif
#if IS_ENABLED(CONFIG_NET_ACT_CT)
+ sizeof(struct nf_conn_act_ct_ext)
#endif
;
}
void *nf_ct_ext_add(struct nf_conn *ct, enum nf_ct_ext_id id, gfp_t gfp)
{
unsigned int newlen, newoff, oldlen, alloc;
struct nf_ct_ext *new;
/* Conntrack must not be confirmed to avoid races on reallocation. */
WARN_ON(nf_ct_is_confirmed(ct));
/* struct nf_ct_ext uses u8 to store offsets/size */
BUILD_BUG_ON(total_extension_size() > 255u);
if (ct->ext) {
const struct nf_ct_ext *old = ct->ext;
if (__nf_ct_ext_exist(old, id))
return NULL;
oldlen = old->len;
} else {
oldlen = sizeof(*new);
}
newoff = ALIGN(oldlen, __alignof__(struct nf_ct_ext));
newlen = newoff + nf_ct_ext_type_len[id];
alloc = max(newlen, NF_CT_EXT_PREALLOC);
new = krealloc(ct->ext, alloc, gfp);
if (!new)
return NULL;
if (!ct->ext) {
memset(new->offset, 0, sizeof(new->offset));
new->gen_id = atomic_read(&nf_conntrack_ext_genid);
}
new->offset[id] = newoff;
new->len = newlen;
memset((void *)new + newoff, 0, newlen - newoff);
ct->ext = new;
return (void *)new + newoff;
}
EXPORT_SYMBOL(nf_ct_ext_add);
/* Use nf_ct_ext_find wrapper. This is only useful for unconfirmed entries. */
void *__nf_ct_ext_find(const struct nf_ct_ext *ext, u8 id)
{
unsigned int gen_id = atomic_read(&nf_conntrack_ext_genid);
unsigned int this_id = READ_ONCE(ext->gen_id);
if (!__nf_ct_ext_exist(ext, id))
return NULL;
if (this_id == 0 || ext->gen_id == gen_id)
return (void *)ext + ext->offset[id];
return NULL;
}
EXPORT_SYMBOL(__nf_ct_ext_find);
void nf_ct_ext_bump_genid(void)
{
unsigned int value = atomic_inc_return(&nf_conntrack_ext_genid);
if (value == UINT_MAX)
atomic_set(&nf_conntrack_ext_genid, 1);
msleep(HZ);
}
|
