// SPDX-License-Identifier: GPL-2.0#include <linux/kernel.h>#include <linux/netfilter.h>#include <linux/netfilter_ipv4.h>#include <linux/netfilter_ipv6.h>#include <net/netfilter/nf_queue.h>#include <net/ip6_checksum.h> #ifdef CONFIG_INET__sum16 nf_ip_checksum(struct sk_buff *skb, unsigned int hook,		       unsigned int dataoff, u8 protocol){	const struct iphdr *iph = ip_hdr(skb);	__sum16 csum = 0; 	switch (skb->ip_summed) {	case CHECKSUM_COMPLETE:		if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)			break;		if ((protocol != IPPROTO_TCP && protocol != IPPROTO_UDP &&		    !csum_fold(skb->csum)) ||		    !csum_tcpudp_magic(iph->saddr, iph->daddr,				       skb->len - dataoff, protocol,				       skb->csum)) {			skb->ip_summed = CHECKSUM_UNNECESSARY;			break;		}		fallthrough;	case CHECKSUM_NONE:		if (protocol != IPPROTO_TCP && protocol != IPPROTO_UDP)			skb->csum = 0;		else			skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,						       skb->len - dataoff,						       protocol, 0);		csum = __skb_checksum_complete(skb);	}	return csum;}EXPORT_SYMBOL(nf_ip_checksum);#endif static __sum16 nf_ip_checksum_partial(struct sk_buff *skb, unsigned int hook,				      unsigned int dataoff, unsigned int len,				      u8 protocol){	const struct iphdr *iph = ip_hdr(skb);	__sum16 csum = 0; 	switch (skb->ip_summed) {	case CHECKSUM_COMPLETE:		if (len == skb->len - dataoff)			return nf_ip_checksum(skb, hook, dataoff, protocol);		fallthrough;	case CHECKSUM_NONE:		skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr, protocol,					       skb->len - dataoff, 0);		skb->ip_summed = CHECKSUM_NONE;		return __skb_checksum_complete_head(skb, dataoff + len);	}	return csum;} __sum16 nf_ip6_checksum(struct sk_buff *skb, unsigned int hook,			unsigned int dataoff, u8 protocol){	const struct ipv6hdr *ip6h = ipv6_hdr(skb);	__sum16 csum = 0; 	switch (skb->ip_summed) {	case CHECKSUM_COMPLETE:		if (hook != NF_INET_PRE_ROUTING && hook != NF_INET_LOCAL_IN)			break;		if (!csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,				     skb->len - dataoff, protocol,				     csum_sub(skb->csum,					      skb_checksum(skb, 0,							   dataoff, 0)))) {			skb->ip_summed = CHECKSUM_UNNECESSARY;			break;		}		fallthrough;	case CHECKSUM_NONE:		skb->csum = ~csum_unfold(				csum_ipv6_magic(&ip6h->saddr, &ip6h->daddr,					     skb->len - dataoff,					     protocol,					     csum_sub(0,						      skb_checksum(skb, 0,								   dataoff, 0))));		csum = __skb_checksum_complete(skb);	}	return csum;}EXPORT_SYMBOL(nf_ip6_checksum); static __sum16 nf_ip6_checksum_partial(struct sk_buff *skb, unsigned int hook,				       unsigned int dataoff, unsigned int len,				       u8 protocol){	const struct ipv6hdr *ip6h = ipv6_hdr(skb);	__wsum hsum;	__sum16 csum = 0; 	switch (skb->ip_summed) {	case CHECKSUM_COMPLETE:		if (len == skb->len - dataoff)			return nf_ip6_checksum(skb, hook, dataoff, protocol);		fallthrough;	case CHECKSUM_NONE:		hsum = skb_checksum(skb, 0, dataoff, 0);		skb->csum = ~csum_unfold(csum_ipv6_magic(&ip6h->saddr,							 &ip6h->daddr,							 skb->len - dataoff,							 protocol,							 csum_sub(0, hsum)));		skb->ip_summed = CHECKSUM_NONE;		return __skb_checksum_complete_head(skb, dataoff + len);	}	return csum;}; __sum16 nf_checksum(struct sk_buff *skb, unsigned int hook,		    unsigned int dataoff, u8 protocol,		    unsigned short family){	__sum16 csum = 0; 	switch (family) {	case AF_INET:		csum = nf_ip_checksum(skb, hook, dataoff, protocol);		break;	case AF_INET6:		csum = nf_ip6_checksum(skb, hook, dataoff, protocol);		break;	} 	return csum;}EXPORT_SYMBOL_GPL(nf_checksum); __sum16 nf_checksum_partial(struct sk_buff *skb, unsigned int hook,			    unsigned int dataoff, unsigned int len,			    u8 protocol, unsigned short family){	__sum16 csum = 0; 	switch (family) {	case AF_INET:		csum = nf_ip_checksum_partial(skb, hook, dataoff, len,					      protocol);		break;	case AF_INET6:		csum = nf_ip6_checksum_partial(skb, hook, dataoff, len,					       protocol);		break;	} 	return csum;}EXPORT_SYMBOL_GPL(nf_checksum_partial); int nf_route(struct net *net, struct dst_entry **dst, struct flowi *fl,	     bool strict, unsigned short family){	int ret = 0; 	switch (family) {	case AF_INET:		ret = nf_ip_route(net, dst, fl, strict);		break;	case AF_INET6:		ret = nf_ip6_route(net, dst, fl, strict);		break;	} 	return ret;}EXPORT_SYMBOL_GPL(nf_route); /* Only get and check the lengths, not do any hop-by-hop stuff. */int nf_ip6_check_hbh_len(struct sk_buff *skb, u32 *plen){	int len, off = sizeof(struct ipv6hdr);	unsigned char *nh; 	if (!pskb_may_pull(skb, off + 8))		return -ENOMEM;	nh = (unsigned char *)(ipv6_hdr(skb) + 1);	len = (nh[1] + 1) << 3; 	if (!pskb_may_pull(skb, off + len))		return -ENOMEM;	nh = skb_network_header(skb); 	off += 2;	len -= 2;	while (len > 0) {		int optlen; 		if (nh[off] == IPV6_TLV_PAD1) {			off++;			len--;			continue;		}		if (len < 2)			return -EBADMSG;		optlen = nh[off + 1] + 2;		if (optlen > len)			return -EBADMSG; 		if (nh[off] == IPV6_TLV_JUMBO) {			u32 pkt_len; 			if (nh[off + 1] != 4 || (off & 3) != 2)				return -EBADMSG;			pkt_len = ntohl(*(__be32 *)(nh + off + 2));			if (pkt_len <= IPV6_MAXPLEN ||			    ipv6_hdr(skb)->payload_len)				return -EBADMSG;			if (pkt_len > skb->len - sizeof(struct ipv6hdr))				return -EBADMSG;			*plen = pkt_len;		}		off += optlen;		len -= optlen;	} 	return len ? -EBADMSG : 0;}EXPORT_SYMBOL_GPL(nf_ip6_check_hbh_len);