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
160
161
162
163
164
165
166
167
168
169
170
171
|
#define KMSG_COMPONENT "IPVS"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
#include <linux/module.h>
#include <linux/kernel.h>
#include <net/ip_vs.h>
#include <net/netfilter/nf_conntrack.h>
#include <linux/netfilter/nf_conntrack_sip.h>
#ifdef CONFIG_IP_VS_DEBUG
static const char *ip_vs_dbg_callid(char *buf, size_t buf_len,
const char *callid, size_t callid_len,
int *idx)
{
size_t len = min(min(callid_len, (size_t)64), buf_len - *idx - 1);
memcpy(buf + *idx, callid, len);
buf[*idx+len] = '\0';
*idx += len + 1;
return buf + *idx - len;
}
#define IP_VS_DEBUG_CALLID(callid, len) \
ip_vs_dbg_callid(ip_vs_dbg_buf, sizeof(ip_vs_dbg_buf), \
callid, len, &ip_vs_dbg_idx)
#endif
static int get_callid(const char *dptr, unsigned int dataoff,
unsigned int datalen,
unsigned int *matchoff, unsigned int *matchlen)
{
/* Find callid */
while (1) {
int ret = ct_sip_get_header(NULL, dptr, dataoff, datalen,
SIP_HDR_CALL_ID, matchoff,
matchlen);
if (ret > 0)
break;
if (!ret)
return 0;
dataoff += *matchoff;
}
/* Empty callid is useless */
if (!*matchlen)
return -EINVAL;
/* Too large is useless */
if (*matchlen > IP_VS_PEDATA_MAXLEN)
return -EINVAL;
/* SIP headers are always followed by a line terminator */
if (*matchoff + *matchlen == datalen)
return -EINVAL;
/* RFC 2543 allows lines to be terminated with CR, LF or CRLF,
* RFC 3261 allows only CRLF, we support both. */
if (*(dptr + *matchoff + *matchlen) != '\r' &&
*(dptr + *matchoff + *matchlen) != '\n')
return -EINVAL;
IP_VS_DBG_BUF(9, "SIP callid %s (%d bytes)\n",
IP_VS_DEBUG_CALLID(dptr + *matchoff, *matchlen),
*matchlen);
return 0;
}
static int
ip_vs_sip_fill_param(struct ip_vs_conn_param *p, struct sk_buff *skb)
{
struct ip_vs_iphdr iph;
unsigned int dataoff, datalen, matchoff, matchlen;
const char *dptr;
int retc;
ip_vs_fill_iphdr(p->af, skb_network_header(skb), &iph);
/* Only useful with UDP */
if (iph.protocol != IPPROTO_UDP)
return -EINVAL;
/* No Data ? */
dataoff = iph.len + sizeof(struct udphdr);
if (dataoff >= skb->len)
return -EINVAL;
if ((retc=skb_linearize(skb)) < 0)
return retc;
dptr = skb->data + dataoff;
datalen = skb->len - dataoff;
if (get_callid(dptr, dataoff, datalen, &matchoff, &matchlen))
return -EINVAL;
/* N.B: pe_data is only set on success,
* this allows fallback to the default persistence logic on failure
*/
p->pe_data = kmemdup(dptr + matchoff, matchlen, GFP_ATOMIC);
if (!p->pe_data)
return -ENOMEM;
p->pe_data_len = matchlen;
return 0;
}
static bool ip_vs_sip_ct_match(const struct ip_vs_conn_param *p,
struct ip_vs_conn *ct)
{
bool ret = false;
if (ct->af == p->af &&
ip_vs_addr_equal(p->af, p->caddr, &ct->caddr) &&
/* protocol should only be IPPROTO_IP if
* d_addr is a fwmark */
ip_vs_addr_equal(p->protocol == IPPROTO_IP ? AF_UNSPEC : p->af,
p->vaddr, &ct->vaddr) &&
ct->vport == p->vport &&
ct->flags & IP_VS_CONN_F_TEMPLATE &&
ct->protocol == p->protocol &&
ct->pe_data && ct->pe_data_len == p->pe_data_len &&
!memcmp(ct->pe_data, p->pe_data, p->pe_data_len))
ret = true;
IP_VS_DBG_BUF(9, "SIP template match %s %s->%s:%d %s\n",
ip_vs_proto_name(p->protocol),
IP_VS_DEBUG_CALLID(p->pe_data, p->pe_data_len),
IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
ret ? "hit" : "not hit");
return ret;
}
static u32 ip_vs_sip_hashkey_raw(const struct ip_vs_conn_param *p,
u32 initval, bool inverse)
{
return jhash(p->pe_data, p->pe_data_len, initval);
}
static int ip_vs_sip_show_pe_data(const struct ip_vs_conn *cp, char *buf)
{
memcpy(buf, cp->pe_data, cp->pe_data_len);
return cp->pe_data_len;
}
static struct ip_vs_pe ip_vs_sip_pe =
{
.name = "sip",
.refcnt = ATOMIC_INIT(0),
.module = THIS_MODULE,
.n_list = LIST_HEAD_INIT(ip_vs_sip_pe.n_list),
.fill_param = ip_vs_sip_fill_param,
.ct_match = ip_vs_sip_ct_match,
.hashkey_raw = ip_vs_sip_hashkey_raw,
.show_pe_data = ip_vs_sip_show_pe_data,
};
static int __init ip_vs_sip_init(void)
{
return register_ip_vs_pe(&ip_vs_sip_pe);
}
static void __exit ip_vs_sip_cleanup(void)
{
unregister_ip_vs_pe(&ip_vs_sip_pe);
}
module_init(ip_vs_sip_init);
module_exit(ip_vs_sip_cleanup);
MODULE_LICENSE("GPL");
|
