| /* |
| * 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> |
| |
| static u32 __ipv6_select_ident(struct net *net, u32 hashrnd, |
| struct in6_addr *dst, 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. |
| */ |
| void 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; |
| |
| 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]); |
| skb_shinfo(skb)->ip6_frag_id = htonl(id); |
| } |
| EXPORT_SYMBOL_GPL(ipv6_proxy_select_ident); |
| |
| void ipv6_select_ident(struct net *net, struct frag_hdr *fhdr, |
| struct rt6_info *rt) |
| { |
| 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, &rt->rt6i_dst.addr, |
| &rt->rt6i_src.addr); |
| fhdr->identification = htonl(id); |
| } |
| EXPORT_SYMBOL(ipv6_select_ident); |
| |
| int ip6_find_1stfragopt(struct sk_buff *skb, u8 **nexthdr) |
| { |
| u16 offset = sizeof(struct ipv6hdr); |
| struct ipv6_opt_hdr *exthdr = |
| (struct ipv6_opt_hdr *)(ipv6_hdr(skb) + 1); |
| unsigned int packet_len = skb_tail_pointer(skb) - |
| skb_network_header(skb); |
| int found_rhdr = 0; |
| *nexthdr = &ipv6_hdr(skb)->nexthdr; |
| |
| while (offset + 1 <= packet_len) { |
| |
| 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; |
| } |
| |
| offset += ipv6_optlen(exthdr); |
| *nexthdr = &exthdr->nexthdr; |
| exthdr = (struct ipv6_opt_hdr *)(skb_network_header(skb) + |
| offset); |
| } |
| |
| return offset; |
| } |
| 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 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); |
| |
| return nf_hook(NFPROTO_IPV6, NF_INET_LOCAL_OUT, skb, NULL, |
| skb_dst(skb)->dev, dst_output); |
| } |
| EXPORT_SYMBOL_GPL(__ip6_local_out); |
| |
| int ip6_local_out(struct sk_buff *skb) |
| { |
| int err; |
| |
| err = __ip6_local_out(skb); |
| if (likely(err == 1)) |
| err = dst_output(skb); |
| |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(ip6_local_out); |