Commit | Line | Data |
---|---|---|
09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
45ca4e0c ME |
2 | #include <net/netfilter/nf_tproxy.h> |
3 | #include <linux/module.h> | |
4 | #include <net/inet6_hashtables.h> | |
5 | #include <net/addrconf.h> | |
6 | #include <net/udp.h> | |
7 | #include <net/tcp.h> | |
8 | ||
9 | const struct in6_addr * | |
10 | nf_tproxy_laddr6(struct sk_buff *skb, const struct in6_addr *user_laddr, | |
11 | const struct in6_addr *daddr) | |
12 | { | |
13 | struct inet6_dev *indev; | |
14 | struct inet6_ifaddr *ifa; | |
15 | struct in6_addr *laddr; | |
16 | ||
17 | if (!ipv6_addr_any(user_laddr)) | |
18 | return user_laddr; | |
19 | laddr = NULL; | |
20 | ||
21 | indev = __in6_dev_get(skb->dev); | |
22 | if (indev) { | |
23 | read_lock_bh(&indev->lock); | |
24 | list_for_each_entry(ifa, &indev->addr_list, if_list) { | |
25 | if (ifa->flags & (IFA_F_TENTATIVE | IFA_F_DEPRECATED)) | |
26 | continue; | |
27 | ||
28 | laddr = &ifa->addr; | |
29 | break; | |
30 | } | |
31 | read_unlock_bh(&indev->lock); | |
32 | } | |
33 | ||
34 | return laddr ? laddr : daddr; | |
35 | } | |
36 | EXPORT_SYMBOL_GPL(nf_tproxy_laddr6); | |
37 | ||
38 | struct sock * | |
39 | nf_tproxy_handle_time_wait6(struct sk_buff *skb, int tproto, int thoff, | |
40 | struct net *net, | |
41 | const struct in6_addr *laddr, | |
42 | const __be16 lport, | |
43 | struct sock *sk) | |
44 | { | |
45 | const struct ipv6hdr *iph = ipv6_hdr(skb); | |
46 | struct tcphdr _hdr, *hp; | |
47 | ||
48 | hp = skb_header_pointer(skb, thoff, sizeof(_hdr), &_hdr); | |
49 | if (hp == NULL) { | |
50 | inet_twsk_put(inet_twsk(sk)); | |
51 | return NULL; | |
52 | } | |
53 | ||
54 | if (hp->syn && !hp->rst && !hp->ack && !hp->fin) { | |
55 | /* SYN to a TIME_WAIT socket, we'd rather redirect it | |
56 | * to a listener socket if there's one */ | |
57 | struct sock *sk2; | |
58 | ||
5711b4e8 | 59 | sk2 = nf_tproxy_get_sock_v6(net, skb, thoff, tproto, |
45ca4e0c ME |
60 | &iph->saddr, |
61 | nf_tproxy_laddr6(skb, laddr, &iph->daddr), | |
62 | hp->source, | |
63 | lport ? lport : hp->dest, | |
64 | skb->dev, NF_TPROXY_LOOKUP_LISTENER); | |
65 | if (sk2) { | |
66 | inet_twsk_deschedule_put(inet_twsk(sk)); | |
67 | sk = sk2; | |
68 | } | |
69 | } | |
70 | ||
71 | return sk; | |
72 | } | |
73 | EXPORT_SYMBOL_GPL(nf_tproxy_handle_time_wait6); | |
74 | ||
75 | struct sock * | |
5711b4e8 | 76 | nf_tproxy_get_sock_v6(struct net *net, struct sk_buff *skb, int thoff, |
45ca4e0c ME |
77 | const u8 protocol, |
78 | const struct in6_addr *saddr, const struct in6_addr *daddr, | |
79 | const __be16 sport, const __be16 dport, | |
80 | const struct net_device *in, | |
81 | const enum nf_tproxy_lookup_t lookup_type) | |
82 | { | |
83 | struct sock *sk; | |
45ca4e0c ME |
84 | |
85 | switch (protocol) { | |
5711b4e8 ME |
86 | case IPPROTO_TCP: { |
87 | struct tcphdr _hdr, *hp; | |
88 | ||
89 | hp = skb_header_pointer(skb, thoff, | |
90 | sizeof(struct tcphdr), &_hdr); | |
91 | if (hp == NULL) | |
92 | return NULL; | |
93 | ||
45ca4e0c ME |
94 | switch (lookup_type) { |
95 | case NF_TPROXY_LOOKUP_LISTENER: | |
45ca4e0c | 96 | sk = inet6_lookup_listener(net, &tcp_hashinfo, skb, |
5711b4e8 | 97 | thoff + __tcp_hdrlen(hp), |
45ca4e0c ME |
98 | saddr, sport, |
99 | daddr, ntohs(dport), | |
100 | in->ifindex, 0); | |
101 | ||
102 | if (sk && !refcount_inc_not_zero(&sk->sk_refcnt)) | |
103 | sk = NULL; | |
104 | /* NOTE: we return listeners even if bound to | |
105 | * 0.0.0.0, those are filtered out in | |
106 | * xt_socket, since xt_TPROXY needs 0 bound | |
107 | * listeners too | |
108 | */ | |
109 | break; | |
110 | case NF_TPROXY_LOOKUP_ESTABLISHED: | |
111 | sk = __inet6_lookup_established(net, &tcp_hashinfo, | |
112 | saddr, sport, daddr, ntohs(dport), | |
113 | in->ifindex, 0); | |
114 | break; | |
115 | default: | |
116 | BUG(); | |
117 | } | |
118 | break; | |
5711b4e8 | 119 | } |
45ca4e0c ME |
120 | case IPPROTO_UDP: |
121 | sk = udp6_lib_lookup(net, saddr, sport, daddr, dport, | |
122 | in->ifindex); | |
123 | if (sk) { | |
124 | int connected = (sk->sk_state == TCP_ESTABLISHED); | |
125 | int wildcard = ipv6_addr_any(&sk->sk_v6_rcv_saddr); | |
126 | ||
127 | /* NOTE: we return listeners even if bound to | |
128 | * 0.0.0.0, those are filtered out in | |
129 | * xt_socket, since xt_TPROXY needs 0 bound | |
130 | * listeners too | |
131 | */ | |
132 | if ((lookup_type == NF_TPROXY_LOOKUP_ESTABLISHED && (!connected || wildcard)) || | |
133 | (lookup_type == NF_TPROXY_LOOKUP_LISTENER && connected)) { | |
134 | sock_put(sk); | |
135 | sk = NULL; | |
136 | } | |
137 | } | |
138 | break; | |
139 | default: | |
140 | WARN_ON(1); | |
141 | sk = NULL; | |
142 | } | |
143 | ||
144 | pr_debug("tproxy socket lookup: proto %u %pI6:%u -> %pI6:%u, lookup type: %d, sock %p\n", | |
145 | protocol, saddr, ntohs(sport), daddr, ntohs(dport), lookup_type, sk); | |
146 | ||
147 | return sk; | |
148 | } | |
149 | EXPORT_SYMBOL_GPL(nf_tproxy_get_sock_v6); | |
150 | ||
151 | MODULE_LICENSE("GPL"); | |
152 | MODULE_AUTHOR("Balazs Scheidler, Krisztian Kovacs"); | |
153 | MODULE_DESCRIPTION("Netfilter IPv4 transparent proxy support"); |