/* * IPv6 library code, needed by static components when full IPv6 support is * not configured or static. These functions are needed by GSO/GRO implementation. */ #include <linux/export.h> #include <net/ip.h> #include <net/ipv6.h> #include <net/ip6_fib.h> #include <net/addrconf.h> #include <net/secure_seq.h> #include <linux/netfilter.h> static u32 __ipv6_select_ident(struct net *net, u32 hashrnd, const struct in6_addr *dst, const struct in6_addr *src) { u32 hash, id; hash = __ipv6_addr_jhash(dst, hashrnd); hash = __ipv6_addr_jhash(src, hash); hash ^= net_hash_mix(net); /* Treat id of 0 as unset and if we get 0 back from ip_idents_reserve, * set the hight order instead thus minimizing possible future * collisions. */ id = ip_idents_reserve(hash, 1); if (unlikely(!id)) id = 1 << 31; return id; } /* This function exists only for tap drivers that must support broken * clients requesting UFO without specifying an IPv6 fragment ID. * * This is similar to ipv6_select_ident() but we use an independent hash * seed to limit information leakage. * * The network header must be set before calling this. */ __be32 ipv6_proxy_select_ident(struct net *net, struct sk_buff *skb) { static u32 ip6_proxy_idents_hashrnd __read_mostly; struct in6_addr buf[2]; struct in6_addr *addrs; u32 id; addrs = skb_header_pointer(skb, skb_network_offset(skb) + offsetof(struct ipv6hdr, saddr), sizeof(buf), buf); if (!addrs) return 0; net_get_random_once(&ip6_proxy_idents_hashrnd, sizeof(ip6_proxy_idents_hashrnd)); id = __ipv6_select_ident(net, ip6_proxy_idents_hashrnd, &addrs[1], &addrs[0]); return htonl(id); } EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident); __be32 ipv6_select_ident(struct net *net, const struct in6_addr *daddr, const struct in6_addr *saddr) { static u32 ip6_idents_hashrnd __read_mostly; u32 id; net_get_random_once(&ip6_idents_hashrnd, sizeof(ip6_idents_hashrnd)); id = __ipv6_select_ident(net, ip6_idents_hashrnd, daddr, saddr); return htonl(id); } EXPORT_SYMBOL(ipv6_select_ident); int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr) { unsigned int offset = sizeof(struct ipv6hdr); unsigned int packet_len = skb_tail_pointer(skb) - skb_network_header(skb); int found_rhdr = 0; *nexthdr = &ipv6_hdr(skb)->nexthdr; while (offset <= packet_len) { struct ipv6_opt_hdr *exthdr; switch (**nexthdr) { case NEXTHDR_HOP: break; case NEXTHDR_ROUTING: found_rhdr = 1; break; case NEXTHDR_DEST: #if IS_ENABLED(CONFIG_IPV6_MIP6) if (ipv6_find_tlv(skb, offset, IPV6_TLV_HAO) >= 0) break; #endif if (found_rhdr) return offset; break; default: return offset; } if (offset + sizeof(struct ipv6_opt_hdr) > packet_len) return -EINVAL; exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) + offset); offset += ipv6_optlen(exthdr); if (offset > IPV6_MAXPLEN) return -EINVAL; *nexthdr = &exthdr->nexthdr; } return -EINVAL; } EXPORT_SYMBOL(ip6_find_1stfragopt); #if IS_ENABLED(CONFIG_IPV6) int ip6_dst_hoplimit(struct dst_entry *dst) { int hoplimit = dst_metric_raw(dst, RTAX_HOPLIMIT); if (hoplimit == 0) { struct net_device *dev = dst->dev; struct inet6_dev *idev; rcu_read_lock(); idev = __in6_dev_get(dev); if (idev) hoplimit = idev->cnf.hop_limit; else hoplimit = dev_net(dev)->ipv6.devconf_all->hop_limit; rcu_read_unlock(); } return hoplimit; } EXPORT_SYMBOL(ip6_dst_hoplimit); #endif int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb) { int len; len = skb->len - sizeof(struct ipv6hdr); if (len > IPV6_MAXPLEN) len = 0; ipv6_hdr(skb)->payload_len = htons(len); IP6CB(skb)->nhoff = offsetof(struct ipv6hdr, nexthdr); /* if egress device is enslaved to an L3 master device pass the * skb to its handler for processing */ skb = l3mdev_ip6_out(sk, skb); if (unlikely(!skb)) return 0; skb->protocol = htons(ETH_P_IPV6); return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, net, sk, skb, NULL, skb_dst(skb)->dev, dst_output); } EXPORT_SYMBOL_GPL(__ip6_local_out); int ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb) { int err; err = __ip6_local_out(net, sk, skb); if (likely(err == 1)) err = dst_output(net, sk, skb); return err; } EXPORT_SYMBOL_GPL(ip6_local_out);