175 lines
4.1 KiB
C
175 lines
4.1 KiB
C
/*
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* IPv6 library code, needed by static components when full IPv6 support is
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* not configured or static. These functions are needed by GSO/GRO implementation.
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*/
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#include <linux/export.h>
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#include <net/ip.h>
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#include <net/ipv6.h>
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#include <net/ip6_fib.h>
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#include <net/addrconf.h>
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#include <net/secure_seq.h>
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static u32 __ipv6_select_ident(struct net *net, u32 hashrnd,
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struct in6_addr *dst, struct in6_addr *src)
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{
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u32 hash, id;
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hash = __ipv6_addr_jhash(dst, hashrnd);
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hash = __ipv6_addr_jhash(src, hash);
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hash ^= net_hash_mix(net);
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/* Treat id of 0 as unset and if we get 0 back from ip_idents_reserve,
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* set the hight order instead thus minimizing possible future
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* collisions.
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*/
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id = ip_idents_reserve(hash, 1);
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if (unlikely(!id))
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id = 1 << 31;
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return id;
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}
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/* This function exists only for tap drivers that must support broken
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* clients requesting UFO without specifying an IPv6 fragment ID.
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*
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* This is similar to ipv6_select_ident() but we use an independent hash
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* seed to limit information leakage.
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*
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* The network header must be set before calling this.
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*/
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void ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb)
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{
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static u32 ip6_proxy_idents_hashrnd __read_mostly;
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struct in6_addr buf[2];
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struct in6_addr *addrs;
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u32 id;
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addrs = skb_header_pointer(skb,
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skb_network_offset(skb) +
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offsetof(struct ipv6hdr, saddr),
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sizeof(buf), buf);
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if (!addrs)
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return;
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net_get_random_once(&ip6_proxy_idents_hashrnd,
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sizeof(ip6_proxy_idents_hashrnd));
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id = __ipv6_select_ident(net, ip6_proxy_idents_hashrnd,
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&addrs[1], &addrs[0]);
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skb_shinfo(skb)->ip6_frag_id = htonl(id);
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}
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EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident);
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u32 ipv6_select_ident(struct net *net, struct rt6_info *rt)
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{
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static u32 ip6_idents_hashrnd __read_mostly;
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u32 id;
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net_get_random_once(&ip6_idents_hashrnd, sizeof(ip6_idents_hashrnd));
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id = __ipv6_select_ident(net, ip6_idents_hashrnd, &rt->rt6i_dst.addr,
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&rt->rt6i_src.addr);
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return htonl(id);
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}
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EXPORT_SYMBOL(ipv6_select_ident);
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int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr)
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{
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u16 offset = sizeof(struct ipv6hdr);
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struct ipv6_opt_hdr *exthdr =
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(struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1);
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unsigned int packet_len = skb_tail_pointer(skb) -
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skb_network_header(skb);
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int found_rhdr = 0;
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*nexthdr = &ipv6_hdr(skb)->nexthdr;
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while (offset + 1 <= packet_len) {
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switch (**nexthdr) {
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case NEXTHDR_HOP:
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break;
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case NEXTHDR_ROUTING:
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found_rhdr = 1;
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break;
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case NEXTHDR_DEST:
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#if IS_ENABLED(CONFIG_IPV6_MIP6)
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if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0)
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break;
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#endif
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if (found_rhdr)
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return offset;
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break;
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default:
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return offset;
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}
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offset += ipv6_optlen(exthdr);
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*nexthdr = &exthdr->nexthdr;
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exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) +
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offset);
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}
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return offset;
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}
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EXPORT_SYMBOL(ip6_find_1stfragopt);
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#if IS_ENABLED(CONFIG_IPV6)
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int ip6_dst_hoplimit(struct dst_entry *dst)
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{
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int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT);
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if (hoplimit == 0) {
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struct net_device *dev = dst->dev;
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struct inet6_dev *idev;
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rcu_read_lock();
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idev = __in6_dev_get(dev);
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if (idev)
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hoplimit = idev->cnf.hop_limit;
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else
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hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit;
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rcu_read_unlock();
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}
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return hoplimit;
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}
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EXPORT_SYMBOL(ip6_dst_hoplimit);
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#endif
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static int __ip6_local_out_sk(struct sock *sk, struct sk_buff *skb)
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{
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int len;
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len = skb->len - sizeof(struct ipv6hdr);
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if (len > IPV6_MAXPLEN)
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len = 0;
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ipv6_hdr(skb)->payload_len = htons(len);
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IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr);
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return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, sk, skb,
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NULL, skb_dst(skb)->dev, dst_output_sk);
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}
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int __ip6_local_out(struct sk_buff *skb)
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{
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return __ip6_local_out_sk(skb->sk, skb);
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}
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EXPORT_SYMBOL_GPL(__ip6_local_out);
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int ip6_local_out_sk(struct sock *sk, struct sk_buff *skb)
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{
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int err;
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err = __ip6_local_out_sk(sk, skb);
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if (likely(err == 1))
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err = dst_output_sk(sk, skb);
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return err;
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}
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EXPORT_SYMBOL_GPL(ip6_local_out_sk);
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int ip6_local_out(struct sk_buff *skb)
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{
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return ip6_local_out_sk(skb->sk, skb);
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}
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EXPORT_SYMBOL_GPL(ip6_local_out);
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