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Commit | Line | Data |
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9c3e1c39 HE |
1 | /* |
2 | * xt_ipvs - kernel module to match IPVS connection properties | |
3 | * | |
4 | * Author: Hannes Eder <heder@google.com> | |
5 | */ | |
6 | ||
7 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
8 | ||
9 | #include <linux/module.h> | |
10 | #include <linux/moduleparam.h> | |
11 | #include <linux/spinlock.h> | |
12 | #include <linux/skbuff.h> | |
13 | #ifdef CONFIG_IP_VS_IPV6 | |
14 | #include <net/ipv6.h> | |
15 | #endif | |
16 | #include <linux/ip_vs.h> | |
17 | #include <linux/types.h> | |
18 | #include <linux/netfilter/x_tables.h> | |
9c3e1c39 HE |
19 | #include <linux/netfilter/xt_ipvs.h> |
20 | #include <net/netfilter/nf_conntrack.h> | |
21 | ||
22 | #include <net/ip_vs.h> | |
23 | ||
24 | MODULE_AUTHOR("Hannes Eder <heder@google.com>"); | |
25 | MODULE_DESCRIPTION("Xtables: match IPVS connection properties"); | |
26 | MODULE_LICENSE("GPL"); | |
27 | MODULE_ALIAS("ipt_ipvs"); | |
28 | MODULE_ALIAS("ip6t_ipvs"); | |
29 | ||
30 | /* borrowed from xt_conntrack */ | |
31 | static bool ipvs_mt_addrcmp(const union nf_inet_addr *kaddr, | |
32 | const union nf_inet_addr *uaddr, | |
33 | const union nf_inet_addr *umask, | |
34 | unsigned int l3proto) | |
35 | { | |
36 | if (l3proto == NFPROTO_IPV4) | |
37 | return ((kaddr->ip ^ uaddr->ip) & umask->ip) == 0; | |
38 | #ifdef CONFIG_IP_VS_IPV6 | |
39 | else if (l3proto == NFPROTO_IPV6) | |
40 | return ipv6_masked_addr_cmp(&kaddr->in6, &umask->in6, | |
41 | &uaddr->in6) == 0; | |
42 | #endif | |
43 | else | |
44 | return false; | |
45 | } | |
46 | ||
47 | static bool | |
48 | ipvs_mt(const struct sk_buff *skb, struct xt_action_param *par) | |
49 | { | |
50 | const struct xt_ipvs_mtinfo *data = par->matchinfo; | |
613dbd95 | 51 | struct netns_ipvs *ipvs = net_ipvs(xt_net(par)); |
9c3e1c39 | 52 | /* ipvs_mt_check ensures that family is only NFPROTO_IPV[46]. */ |
613dbd95 | 53 | const u_int8_t family = xt_family(par); |
9c3e1c39 HE |
54 | struct ip_vs_iphdr iph; |
55 | struct ip_vs_protocol *pp; | |
56 | struct ip_vs_conn *cp; | |
57 | bool match = true; | |
58 | ||
59 | if (data->bitmask == XT_IPVS_IPVS_PROPERTY) { | |
60 | match = skb->ipvs_property ^ | |
61 | !!(data->invert & XT_IPVS_IPVS_PROPERTY); | |
62 | goto out; | |
63 | } | |
64 | ||
65 | /* other flags than XT_IPVS_IPVS_PROPERTY are set */ | |
66 | if (!skb->ipvs_property) { | |
67 | match = false; | |
68 | goto out; | |
69 | } | |
70 | ||
4fd9beef | 71 | ip_vs_fill_iph_skb(family, skb, true, &iph); |
9c3e1c39 HE |
72 | |
73 | if (data->bitmask & XT_IPVS_PROTO) | |
74 | if ((iph.protocol == data->l4proto) ^ | |
75 | !(data->invert & XT_IPVS_PROTO)) { | |
76 | match = false; | |
77 | goto out; | |
78 | } | |
79 | ||
80 | pp = ip_vs_proto_get(iph.protocol); | |
81 | if (unlikely(!pp)) { | |
82 | match = false; | |
83 | goto out; | |
84 | } | |
85 | ||
86 | /* | |
87 | * Check if the packet belongs to an existing entry | |
88 | */ | |
0cf705c8 | 89 | cp = pp->conn_out_get(ipvs, family, skb, &iph); |
9c3e1c39 HE |
90 | if (unlikely(cp == NULL)) { |
91 | match = false; | |
92 | goto out; | |
93 | } | |
94 | ||
95 | /* | |
96 | * We found a connection, i.e. ct != 0, make sure to call | |
97 | * __ip_vs_conn_put before returning. In our case jump to out_put_con. | |
98 | */ | |
99 | ||
100 | if (data->bitmask & XT_IPVS_VPORT) | |
101 | if ((cp->vport == data->vport) ^ | |
102 | !(data->invert & XT_IPVS_VPORT)) { | |
103 | match = false; | |
104 | goto out_put_cp; | |
105 | } | |
106 | ||
107 | if (data->bitmask & XT_IPVS_VPORTCTL) | |
108 | if ((cp->control != NULL && | |
109 | cp->control->vport == data->vportctl) ^ | |
110 | !(data->invert & XT_IPVS_VPORTCTL)) { | |
111 | match = false; | |
112 | goto out_put_cp; | |
113 | } | |
114 | ||
115 | if (data->bitmask & XT_IPVS_DIR) { | |
116 | enum ip_conntrack_info ctinfo; | |
117 | struct nf_conn *ct = nf_ct_get(skb, &ctinfo); | |
118 | ||
ab8bc7ed | 119 | if (ct == NULL) { |
9c3e1c39 HE |
120 | match = false; |
121 | goto out_put_cp; | |
122 | } | |
123 | ||
124 | if ((ctinfo >= IP_CT_IS_REPLY) ^ | |
125 | !!(data->invert & XT_IPVS_DIR)) { | |
126 | match = false; | |
127 | goto out_put_cp; | |
128 | } | |
129 | } | |
130 | ||
131 | if (data->bitmask & XT_IPVS_METHOD) | |
132 | if (((cp->flags & IP_VS_CONN_F_FWD_MASK) == data->fwd_method) ^ | |
133 | !(data->invert & XT_IPVS_METHOD)) { | |
134 | match = false; | |
135 | goto out_put_cp; | |
136 | } | |
137 | ||
138 | if (data->bitmask & XT_IPVS_VADDR) { | |
139 | if (ipvs_mt_addrcmp(&cp->vaddr, &data->vaddr, | |
140 | &data->vmask, family) ^ | |
141 | !(data->invert & XT_IPVS_VADDR)) { | |
142 | match = false; | |
143 | goto out_put_cp; | |
144 | } | |
145 | } | |
146 | ||
147 | out_put_cp: | |
148 | __ip_vs_conn_put(cp); | |
149 | out: | |
150 | pr_debug("match=%d\n", match); | |
151 | return match; | |
152 | } | |
153 | ||
154 | static int ipvs_mt_check(const struct xt_mtchk_param *par) | |
155 | { | |
156 | if (par->family != NFPROTO_IPV4 | |
157 | #ifdef CONFIG_IP_VS_IPV6 | |
158 | && par->family != NFPROTO_IPV6 | |
159 | #endif | |
160 | ) { | |
161 | pr_info("protocol family %u not supported\n", par->family); | |
162 | return -EINVAL; | |
163 | } | |
164 | ||
165 | return 0; | |
166 | } | |
167 | ||
168 | static struct xt_match xt_ipvs_mt_reg __read_mostly = { | |
169 | .name = "ipvs", | |
170 | .revision = 0, | |
171 | .family = NFPROTO_UNSPEC, | |
172 | .match = ipvs_mt, | |
173 | .checkentry = ipvs_mt_check, | |
174 | .matchsize = XT_ALIGN(sizeof(struct xt_ipvs_mtinfo)), | |
175 | .me = THIS_MODULE, | |
176 | }; | |
177 | ||
178 | static int __init ipvs_mt_init(void) | |
179 | { | |
180 | return xt_register_match(&xt_ipvs_mt_reg); | |
181 | } | |
182 | ||
183 | static void __exit ipvs_mt_exit(void) | |
184 | { | |
185 | xt_unregister_match(&xt_ipvs_mt_reg); | |
186 | } | |
187 | ||
188 | module_init(ipvs_mt_init); | |
189 | module_exit(ipvs_mt_exit); |