// SPDX-License-Identifier: GPL-2.0-only/* * 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,			       const struct in6_addr *dst,			       const struct in6_addr *src){	return get_random_u32_above(0);} /* 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){	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; 	id = __ipv6_select_ident(net, &addrs[1], &addrs[0]);	return htonl(id);} __be32 ipv6_select_ident(struct net *net,			 const struct in6_addr *daddr,			 const struct in6_addr *saddr){	u32 id; 	id = __ipv6_select_ident(net, 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); int __ip6_local_out(struct net *net, struct sock *sk, struct sk_buff *skb){	ipv6_set_payload_len(ipv6_hdr(skb), skb->len - sizeof(struct ipv6hdr));	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_dev(skb),		       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);