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Commit | Line | Data |
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3c73a036 VY |
1 | /* |
2 | * IPv6 library code, needed by static components when full IPv6 support is | |
3 | * not configured or static. These functions are needed by GSO/GRO implementation. | |
4 | */ | |
5 | #include <linux/export.h> | |
5188cd44 | 6 | #include <net/ip.h> |
3c73a036 VY |
7 | #include <net/ipv6.h> |
8 | #include <net/ip6_fib.h> | |
3ce9b35f | 9 | #include <net/addrconf.h> |
6dfac5c3 | 10 | #include <net/secure_seq.h> |
a263653e | 11 | #include <linux/netfilter.h> |
3c73a036 | 12 | |
14bc2d05 | 13 | static u32 __ipv6_select_ident(struct net *net, |
fd0273d7 MKL |
14 | const struct in6_addr *dst, |
15 | const struct in6_addr *src) | |
0508c07f | 16 | { |
14bc2d05 ED |
17 | const struct { |
18 | struct in6_addr dst; | |
19 | struct in6_addr src; | |
20 | } __aligned(SIPHASH_ALIGNMENT) combined = { | |
21 | .dst = *dst, | |
22 | .src = *src, | |
23 | }; | |
0508c07f VY |
24 | u32 hash, id; |
25 | ||
14bc2d05 ED |
26 | /* Note the following code is not safe, but this is okay. */ |
27 | if (unlikely(siphash_key_is_zero(&net->ipv4.ip_id_key))) | |
28 | get_random_bytes(&net->ipv4.ip_id_key, | |
29 | sizeof(net->ipv4.ip_id_key)); | |
30 | ||
31 | hash = siphash(&combined, sizeof(combined), &net->ipv4.ip_id_key); | |
0508c07f VY |
32 | |
33 | /* Treat id of 0 as unset and if we get 0 back from ip_idents_reserve, | |
34 | * set the hight order instead thus minimizing possible future | |
35 | * collisions. | |
36 | */ | |
37 | id = ip_idents_reserve(hash, 1); | |
38 | if (unlikely(!id)) | |
39 | id = 1 << 31; | |
40 | ||
41 | return id; | |
42 | } | |
43 | ||
0c19f846 WB |
44 | /* This function exists only for tap drivers that must support broken |
45 | * clients requesting UFO without specifying an IPv6 fragment ID. | |
46 | * | |
47 | * This is similar to ipv6_select_ident() but we use an independent hash | |
48 | * seed to limit information leakage. | |
49 | * | |
50 | * The network header must be set before calling this. | |
51 | */ | |
52 | __be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb) | |
53 | { | |
0c19f846 WB |
54 | struct in6_addr buf[2]; |
55 | struct in6_addr *addrs; | |
56 | u32 id; | |
57 | ||
58 | addrs = skb_header_pointer(skb, | |
59 | skb_network_offset(skb) + | |
60 | offsetof(struct ipv6hdr, saddr), | |
61 | sizeof(buf), buf); | |
62 | if (!addrs) | |
63 | return 0; | |
64 | ||
14bc2d05 | 65 | id = __ipv6_select_ident(net, &addrs[1], &addrs[0]); |
0c19f846 WB |
66 | return htonl(id); |
67 | } | |
68 | EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident); | |
69 | ||
7f159867 ED |
70 | __be32 ipv6_select_ident(struct net *net, |
71 | const struct in6_addr *daddr, | |
72 | const struct in6_addr *saddr) | |
0508c07f | 73 | { |
0508c07f VY |
74 | u32 id; |
75 | ||
14bc2d05 | 76 | id = __ipv6_select_ident(net, daddr, saddr); |
286c2349 | 77 | return htonl(id); |
0508c07f VY |
78 | } |
79 | EXPORT_SYMBOL(ipv6_select_ident); | |
80 | ||
3c73a036 VY |
81 | int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr) |
82 | { | |
6399f1fa | 83 | unsigned int offset = sizeof(struct ipv6hdr); |
29a3cad5 SH |
84 | unsigned int packet_len = skb_tail_pointer(skb) - |
85 | skb_network_header(skb); | |
3c73a036 VY |
86 | int found_rhdr = 0; |
87 | *nexthdr = &ipv6_hdr(skb)->nexthdr; | |
88 | ||
2423496a CG |
89 | while (offset <= packet_len) { |
90 | struct ipv6_opt_hdr *exthdr; | |
3c73a036 VY |
91 | |
92 | switch (**nexthdr) { | |
93 | ||
94 | case NEXTHDR_HOP: | |
95 | break; | |
96 | case NEXTHDR_ROUTING: | |
97 | found_rhdr = 1; | |
98 | break; | |
99 | case NEXTHDR_DEST: | |
100 | #if IS_ENABLED(CONFIG_IPV6_MIP6) | |
101 | if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) | |
102 | break; | |
103 | #endif | |
104 | if (found_rhdr) | |
105 | return offset; | |
106 | break; | |
67ba4152 | 107 | default: |
3c73a036 VY |
108 | return offset; |
109 | } | |
110 | ||
2423496a CG |
111 | if (offset + sizeof(struct ipv6_opt_hdr) > packet_len) |
112 | return -EINVAL; | |
113 | ||
3c73a036 VY |
114 | exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) + |
115 | offset); | |
3de33e1b SB |
116 | offset += ipv6_optlen(exthdr); |
117 | if (offset > IPV6_MAXPLEN) | |
6399f1fa | 118 | return -EINVAL; |
2423496a | 119 | *nexthdr = &exthdr->nexthdr; |
3c73a036 VY |
120 | } |
121 | ||
2423496a | 122 | return -EINVAL; |
3c73a036 VY |
123 | } |
124 | EXPORT_SYMBOL(ip6_find_1stfragopt); | |
3ce9b35f CW |
125 | |
126 | #if IS_ENABLED(CONFIG_IPV6) | |
127 | int ip6_dst_hoplimit(struct dst_entry *dst) | |
128 | { | |
129 | int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); | |
130 | if (hoplimit == 0) { | |
131 | struct net_device *dev = dst->dev; | |
132 | struct inet6_dev *idev; | |
133 | ||
134 | rcu_read_lock(); | |
135 | idev = __in6_dev_get(dev); | |
136 | if (idev) | |
137 | hoplimit = idev->cnf.hop_limit; | |
138 | else | |
139 | hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit; | |
140 | rcu_read_unlock(); | |
141 | } | |
142 | return hoplimit; | |
143 | } | |
144 | EXPORT_SYMBOL(ip6_dst_hoplimit); | |
145 | #endif | |
788787b5 | 146 | |
cf91a99d | 147 | int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb) |
788787b5 CW |
148 | { |
149 | int len; | |
150 | ||
151 | len = skb->len - sizeof(struct ipv6hdr); | |
152 | if (len > IPV6_MAXPLEN) | |
153 | len = 0; | |
154 | ipv6_hdr(skb)->payload_len = htons(len); | |
f6c20c59 | 155 | IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr); |
788787b5 | 156 | |
a8e3e1a9 DA |
157 | /* if egress device is enslaved to an L3 master device pass the |
158 | * skb to its handler for processing | |
159 | */ | |
160 | skb = l3mdev_ip6_out(sk, skb); | |
161 | if (unlikely(!skb)) | |
162 | return 0; | |
163 | ||
b4e479a9 EC |
164 | skb->protocol = htons(ETH_P_IPV6); |
165 | ||
29a26a56 EB |
166 | return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, |
167 | net, sk, skb, NULL, skb_dst(skb)->dev, | |
13206b6b | 168 | dst_output); |
788787b5 CW |
169 | } |
170 | EXPORT_SYMBOL_GPL(__ip6_local_out); | |
171 | ||
33224b16 | 172 | int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb) |
788787b5 CW |
173 | { |
174 | int err; | |
175 | ||
cf91a99d | 176 | err = __ip6_local_out(net, sk, skb); |
788787b5 | 177 | if (likely(err == 1)) |
13206b6b | 178 | err = dst_output(net, sk, skb); |
788787b5 CW |
179 | |
180 | return err; | |
181 | } | |
182 | EXPORT_SYMBOL_GPL(ip6_local_out); |