1
2#define KMSG_COMPONENT "IPVS"
3#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
4
5#include <linux/module.h>
6#include <linux/kernel.h>
7
8#include <net/ip_vs.h>
9#include <net/netfilter/nf_conntrack.h>
10#include <linux/netfilter/nf_conntrack_sip.h>
11
12#ifdef CONFIG_IP_VS_DEBUG
13static const char *ip_vs_dbg_callid(char *buf, size_t buf_len,
14 const char *callid, size_t callid_len,
15 int *idx)
16{
17 size_t max_len = 64;
18 size_t len = min3(max_len, callid_len, buf_len - *idx - 1);
19 memcpy(buf + *idx, callid, len);
20 buf[*idx+len] = '\0';
21 *idx += len + 1;
22 return buf + *idx - len;
23}
24
25#define IP_VS_DEBUG_CALLID(callid, len) \
26 ip_vs_dbg_callid(ip_vs_dbg_buf, sizeof(ip_vs_dbg_buf), \
27 callid, len, &ip_vs_dbg_idx)
28#endif
29
30static int get_callid(const char *dptr, unsigned int dataoff,
31 unsigned int datalen,
32 unsigned int *matchoff, unsigned int *matchlen)
33{
34
35 while (1) {
36 int ret = ct_sip_get_header(NULL, dptr, dataoff, datalen,
37 SIP_HDR_CALL_ID, matchoff,
38 matchlen);
39 if (ret > 0)
40 break;
41 if (!ret)
42 return -EINVAL;
43 dataoff += *matchoff;
44 }
45
46
47 if (*matchlen > IP_VS_PEDATA_MAXLEN)
48 return -EINVAL;
49
50
51 if (*matchoff + *matchlen == datalen)
52 return -EINVAL;
53
54
55
56 if (*(dptr + *matchoff + *matchlen) != '\r' &&
57 *(dptr + *matchoff + *matchlen) != '\n')
58 return -EINVAL;
59
60 IP_VS_DBG_BUF(9, "SIP callid %s (%d bytes)\n",
61 IP_VS_DEBUG_CALLID(dptr + *matchoff, *matchlen),
62 *matchlen);
63 return 0;
64}
65
66static int
67ip_vs_sip_fill_param(struct ip_vs_conn_param *p, struct sk_buff *skb)
68{
69 struct ip_vs_iphdr iph;
70 unsigned int dataoff, datalen, matchoff, matchlen;
71 const char *dptr;
72 int retc;
73
74 retc = ip_vs_fill_iph_skb(p->af, skb, false, &iph);
75
76
77 if (!retc || iph.protocol != IPPROTO_UDP)
78 return -EINVAL;
79
80
81
82 dataoff = iph.len + sizeof(struct udphdr);
83
84 if (dataoff >= skb->len)
85 return -EINVAL;
86 retc = skb_linearize(skb);
87 if (retc < 0)
88 return retc;
89 dptr = skb->data + dataoff;
90 datalen = skb->len - dataoff;
91
92 if (get_callid(dptr, 0, datalen, &matchoff, &matchlen))
93 return -EINVAL;
94
95
96
97
98 p->pe_data = kmemdup(dptr + matchoff, matchlen, GFP_ATOMIC);
99 if (!p->pe_data)
100 return -ENOMEM;
101
102 p->pe_data_len = matchlen;
103
104 return 0;
105}
106
107static bool ip_vs_sip_ct_match(const struct ip_vs_conn_param *p,
108 struct ip_vs_conn *ct)
109
110{
111 bool ret = false;
112
113 if (ct->af == p->af &&
114 ip_vs_addr_equal(p->af, p->caddr, &ct->caddr) &&
115
116
117 ip_vs_addr_equal(p->protocol == IPPROTO_IP ? AF_UNSPEC : p->af,
118 p->vaddr, &ct->vaddr) &&
119 ct->vport == p->vport &&
120 ct->flags & IP_VS_CONN_F_TEMPLATE &&
121 ct->protocol == p->protocol &&
122 ct->pe_data && ct->pe_data_len == p->pe_data_len &&
123 !memcmp(ct->pe_data, p->pe_data, p->pe_data_len))
124 ret = true;
125
126 IP_VS_DBG_BUF(9, "SIP template match %s %s->%s:%d %s\n",
127 ip_vs_proto_name(p->protocol),
128 IP_VS_DEBUG_CALLID(p->pe_data, p->pe_data_len),
129 IP_VS_DBG_ADDR(p->af, p->vaddr), ntohs(p->vport),
130 ret ? "hit" : "not hit");
131
132 return ret;
133}
134
135static u32 ip_vs_sip_hashkey_raw(const struct ip_vs_conn_param *p,
136 u32 initval, bool inverse)
137{
138 return jhash(p->pe_data, p->pe_data_len, initval);
139}
140
141static int ip_vs_sip_show_pe_data(const struct ip_vs_conn *cp, char *buf)
142{
143 memcpy(buf, cp->pe_data, cp->pe_data_len);
144 return cp->pe_data_len;
145}
146
147static struct ip_vs_conn *
148ip_vs_sip_conn_out(struct ip_vs_service *svc,
149 struct ip_vs_dest *dest,
150 struct sk_buff *skb,
151 const struct ip_vs_iphdr *iph,
152 __be16 dport,
153 __be16 cport)
154{
155 if (likely(iph->protocol == IPPROTO_UDP))
156 return ip_vs_new_conn_out(svc, dest, skb, iph, dport, cport);
157
158 return NULL;
159}
160
161static struct ip_vs_pe ip_vs_sip_pe =
162{
163 .name = "sip",
164 .refcnt = ATOMIC_INIT(0),
165 .module = THIS_MODULE,
166 .n_list = LIST_HEAD_INIT(ip_vs_sip_pe.n_list),
167 .fill_param = ip_vs_sip_fill_param,
168 .ct_match = ip_vs_sip_ct_match,
169 .hashkey_raw = ip_vs_sip_hashkey_raw,
170 .show_pe_data = ip_vs_sip_show_pe_data,
171 .conn_out = ip_vs_sip_conn_out,
172};
173
174static int __init ip_vs_sip_init(void)
175{
176 return register_ip_vs_pe(&ip_vs_sip_pe);
177}
178
179static void __exit ip_vs_sip_cleanup(void)
180{
181 unregister_ip_vs_pe(&ip_vs_sip_pe);
182 synchronize_rcu();
183}
184
185module_init(ip_vs_sip_init);
186module_exit(ip_vs_sip_cleanup);
187MODULE_LICENSE("GPL");
188
