// SPDX-License-Identifier: GPL-2.0-or-later/* *	IPV6 GSO/GRO offload support *	Linux INET6 implementation */ #include <linux/kernel.h>#include <linux/socket.h>#include <linux/netdevice.h>#include <linux/skbuff.h>#include <linux/printk.h> #include <net/protocol.h>#include <net/ipv6.h>#include <net/inet_common.h>#include <net/tcp.h>#include <net/udp.h>#include <net/gro.h>#include <net/gso.h> #include "ip6_offload.h"#include "tcpv6_offload.c" static int ipv6_gro_pull_exthdrs(struct sk_buff *skb, int off, int proto){	const struct net_offload *ops = NULL;	struct ipv6_opt_hdr *opth; 	for (;;) {		int len; 		ops = rcu_dereference(inet6_offloads[proto]); 		if (unlikely(!ops))			break; 		if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))			break; 		opth = skb_gro_header(skb, off + sizeof(*opth), off);		if (unlikely(!opth))			break; 		len = ipv6_optlen(opth); 		opth = skb_gro_header(skb, off + len, off);		if (unlikely(!opth))			break;		proto = opth->nexthdr; 		off += len;	} 	skb_gro_pull(skb, off - skb_gro_receive_network_offset(skb));	return proto;} static int ipv6_gso_pull_exthdrs(struct sk_buff *skb, int proto){	const struct net_offload *ops = NULL; 	for (;;) {		struct ipv6_opt_hdr *opth;		int len; 		ops = rcu_dereference(inet6_offloads[proto]); 		if (unlikely(!ops))			break; 		if (!(ops->flags & INET6_PROTO_GSO_EXTHDR))			break; 		if (unlikely(!pskb_may_pull(skb, 8)))			break; 		opth = (void *)skb->data;		len = ipv6_optlen(opth); 		if (unlikely(!pskb_may_pull(skb, len)))			break; 		opth = (void *)skb->data;		proto = opth->nexthdr;		__skb_pull(skb, len);	} 	return proto;} static struct sk_buff *ipv6_gso_segment(struct sk_buff *skb,	netdev_features_t features){	struct sk_buff *segs = ERR_PTR(-EINVAL);	struct ipv6hdr *ipv6h;	const struct net_offload *ops;	int proto;	struct frag_hdr *fptr;	unsigned int payload_len;	u8 *prevhdr;	int offset = 0;	bool encap, udpfrag;	int nhoff;	bool gso_partial; 	skb_reset_network_header(skb);	nhoff = skb_network_header(skb) - skb_mac_header(skb);	if (unlikely(!pskb_may_pull(skb, sizeof(*ipv6h))))		goto out; 	encap = SKB_GSO_CB(skb)->encap_level > 0;	if (encap)		features &= skb->dev->hw_enc_features;	SKB_GSO_CB(skb)->encap_level += sizeof(*ipv6h); 	ipv6h = ipv6_hdr(skb);	__skb_pull(skb, sizeof(*ipv6h));	segs = ERR_PTR(-EPROTONOSUPPORT); 	proto = ipv6_gso_pull_exthdrs(skb, ipv6h->nexthdr); 	if (skb->encapsulation &&	    skb_shinfo(skb)->gso_type & (SKB_GSO_IPXIP4 | SKB_GSO_IPXIP6))		udpfrag = proto == IPPROTO_UDP && encap &&			  (skb_shinfo(skb)->gso_type & SKB_GSO_UDP);	else		udpfrag = proto == IPPROTO_UDP && !skb->encapsulation &&			  (skb_shinfo(skb)->gso_type & SKB_GSO_UDP); 	ops = rcu_dereference(inet6_offloads[proto]);	if (likely(ops && ops->callbacks.gso_segment)) {		if (!skb_reset_transport_header_careful(skb))			goto out; 		segs = ops->callbacks.gso_segment(skb, features);		if (!segs)			skb->network_header = skb_mac_header(skb) + nhoff - skb->head;	} 	if (IS_ERR_OR_NULL(segs))		goto out; 	gso_partial = !!(skb_shinfo(segs)->gso_type & SKB_GSO_PARTIAL); 	for (skb = segs; skb; skb = skb->next) {		ipv6h = (struct ipv6hdr *)(skb_mac_header(skb) + nhoff);		if (gso_partial && skb_is_gso(skb))			payload_len = skb_shinfo(skb)->gso_size +				      SKB_GSO_CB(skb)->data_offset +				      skb->head - (unsigned char *)(ipv6h + 1);		else			payload_len = skb->len - nhoff - sizeof(*ipv6h);		ipv6h->payload_len = htons(payload_len);		skb->network_header = (u8 *)ipv6h - skb->head;		skb_reset_mac_len(skb); 		if (udpfrag) {			int err = ip6_find_1stfragopt(skb, &prevhdr);			if (err < 0) {				kfree_skb_list(segs);				return ERR_PTR(err);			}			fptr = (struct frag_hdr *)((u8 *)ipv6h + err);			fptr->frag_off = htons(offset);			if (skb->next)				fptr->frag_off |= htons(IP6_MF);			offset += (ntohs(ipv6h->payload_len) -				   sizeof(struct frag_hdr));		}		if (encap)			skb_reset_inner_headers(skb);	} out:	return segs;} /* Return the total length of all the extension hdrs, following the same * logic in ipv6_gso_pull_exthdrs() when parsing ext-hdrs. */static int ipv6_exthdrs_len(struct ipv6hdr *iph,			    const struct net_offload **opps){	struct ipv6_opt_hdr *opth = (void *)iph;	int len = 0, proto, optlen = sizeof(*iph); 	proto = iph->nexthdr;	for (;;) {		*opps = rcu_dereference(inet6_offloads[proto]);		if (unlikely(!(*opps)))			break;		if (!((*opps)->flags & INET6_PROTO_GSO_EXTHDR))			break; 		opth = (void *)opth + optlen;		optlen = ipv6_optlen(opth);		len += optlen;		proto = opth->nexthdr;	}	return len;} INDIRECT_CALLABLE_SCOPE struct sk_buff *ipv6_gro_receive(struct list_head *head,							 struct sk_buff *skb){	const struct net_offload *ops;	struct sk_buff *pp = NULL;	struct sk_buff *p;	struct ipv6hdr *iph;	unsigned int nlen;	unsigned int hlen;	unsigned int off;	u16 flush = 1;	int proto; 	off = skb_gro_offset(skb);	hlen = off + sizeof(*iph);	iph = skb_gro_header(skb, hlen, off);	if (unlikely(!iph))		goto out; 	NAPI_GRO_CB(skb)->network_offsets[NAPI_GRO_CB(skb)->encap_mark] = off; 	flush += ntohs(iph->payload_len) != skb->len - hlen; 	proto = iph->nexthdr;	ops = rcu_dereference(inet6_offloads[proto]);	if (!ops || !ops->callbacks.gro_receive) {		proto = ipv6_gro_pull_exthdrs(skb, hlen, proto); 		ops = rcu_dereference(inet6_offloads[proto]);		if (!ops || !ops->callbacks.gro_receive)			goto out; 		iph = skb_gro_network_header(skb);	} else {		skb_gro_pull(skb, sizeof(*iph));	} 	skb_set_transport_header(skb, skb_gro_offset(skb)); 	NAPI_GRO_CB(skb)->proto = proto; 	flush--;	nlen = skb_gro_offset(skb) - off; 	list_for_each_entry(p, head, list) {		const struct ipv6hdr *iph2;		__be32 first_word; /* <Version:4><Traffic_Class:8><Flow_Label:20> */ 		if (!NAPI_GRO_CB(p)->same_flow)			continue; 		iph2 = (struct ipv6hdr *)(p->data + off);		first_word = *(__be32 *)iph ^ *(__be32 *)iph2; 		/* All fields must match except length and Traffic Class.		 * XXX skbs on the gro_list have all been parsed and pulled		 * already so we don't need to compare nlen		 * (nlen != (sizeof(*iph2) + ipv6_exthdrs_len(iph2, &ops)))		 * memcmp() alone below is sufficient, right?		 */		 if ((first_word & htonl(0xF00FFFFF)) ||		     !ipv6_addr_equal(&iph->saddr, &iph2->saddr) ||		     !ipv6_addr_equal(&iph->daddr, &iph2->daddr) ||		     iph->nexthdr != iph2->nexthdr) {not_same_flow:			NAPI_GRO_CB(p)->same_flow = 0;			continue;		}		if (unlikely(nlen > sizeof(struct ipv6hdr))) {			if (memcmp(iph + 1, iph2 + 1,				   nlen - sizeof(struct ipv6hdr)))				goto not_same_flow;		}	} 	NAPI_GRO_CB(skb)->flush |= flush; 	skb_gro_postpull_rcsum(skb, iph, nlen); 	if (unlikely(gro_recursion_inc_test(skb))) {		flush = 1;		goto out;	} 	if (likely(proto == IPPROTO_TCP))		pp = tcp6_gro_receive(head, skb);#if IS_ENABLED(CONFIG_IPV6)	else if (likely(proto == IPPROTO_UDP))		pp = udp6_gro_receive(head, skb);#endif	else		pp = ops->callbacks.gro_receive(head, skb);out:	skb_gro_flush_final(skb, pp, flush); 	return pp;}EXPORT_INDIRECT_CALLABLE(ipv6_gro_receive); static struct sk_buff *sit_ip6ip6_gro_receive(struct list_head *head,					      struct sk_buff *skb){	/* Common GRO receive for SIT and IP6IP6 */ 	if (NAPI_GRO_CB(skb)->encap_mark) {		NAPI_GRO_CB(skb)->flush = 1;		return NULL;	} 	NAPI_GRO_CB(skb)->encap_mark = 1; 	return ipv6_gro_receive(head, skb);} static struct sk_buff *ip4ip6_gro_receive(struct list_head *head,					  struct sk_buff *skb){	/* Common GRO receive for SIT and IP6IP6 */ 	if (NAPI_GRO_CB(skb)->encap_mark) {		NAPI_GRO_CB(skb)->flush = 1;		return NULL;	} 	NAPI_GRO_CB(skb)->encap_mark = 1; 	return inet_gro_receive(head, skb);} INDIRECT_CALLABLE_SCOPE int ipv6_gro_complete(struct sk_buff *skb, int nhoff){	const struct net_offload *ops;	struct ipv6hdr *iph;	int err = -ENOSYS; 	if (skb->encapsulation) {		skb_set_inner_protocol(skb, cpu_to_be16(ETH_P_IPV6));		skb_set_inner_network_header(skb, nhoff);	} 	iph = (struct ipv6hdr *)(skb->data + nhoff);	ipv6_set_payload_len(iph, skb->len - nhoff - sizeof(*iph)); 	nhoff += sizeof(*iph) + ipv6_exthdrs_len(iph, &ops); 	if (likely(ops == &net_hotdata.tcpv6_offload))		return tcp6_gro_complete(skb, nhoff);#if IS_ENABLED(CONFIG_IPV6)	if (ops == &net_hotdata.udpv6_offload)		return udp6_gro_complete(skb, nhoff);#endif 	if (WARN_ON(!ops || !ops->callbacks.gro_complete))		goto out; 	err = ops->callbacks.gro_complete(skb, nhoff); out:	return err;}EXPORT_INDIRECT_CALLABLE(ipv6_gro_complete); static int sit_gro_complete(struct sk_buff *skb, int nhoff){	skb->encapsulation = 1;	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP4;	return ipv6_gro_complete(skb, nhoff);} static int ip6ip6_gro_complete(struct sk_buff *skb, int nhoff){	skb->encapsulation = 1;	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;	return ipv6_gro_complete(skb, nhoff);} static int ip4ip6_gro_complete(struct sk_buff *skb, int nhoff){	skb->encapsulation = 1;	skb_shinfo(skb)->gso_type |= SKB_GSO_IPXIP6;	return inet_gro_complete(skb, nhoff);}  static struct sk_buff *sit_gso_segment(struct sk_buff *skb,				       netdev_features_t features){	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP4))		return ERR_PTR(-EINVAL); 	return ipv6_gso_segment(skb, features);} static struct sk_buff *ip4ip6_gso_segment(struct sk_buff *skb,					  netdev_features_t features){	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))		return ERR_PTR(-EINVAL); 	return inet_gso_segment(skb, features);} static struct sk_buff *ip6ip6_gso_segment(struct sk_buff *skb,					  netdev_features_t features){	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_IPXIP6))		return ERR_PTR(-EINVAL); 	return ipv6_gso_segment(skb, features);} static const struct net_offload sit_offload = {	.callbacks = {		.gso_segment	= sit_gso_segment,		.gro_receive    = sit_ip6ip6_gro_receive,		.gro_complete   = sit_gro_complete,	},}; static const struct net_offload ip4ip6_offload = {	.callbacks = {		.gso_segment	= ip4ip6_gso_segment,		.gro_receive    = ip4ip6_gro_receive,		.gro_complete   = ip4ip6_gro_complete,	},}; static const struct net_offload ip6ip6_offload = {	.callbacks = {		.gso_segment	= ip6ip6_gso_segment,		.gro_receive    = sit_ip6ip6_gro_receive,		.gro_complete   = ip6ip6_gro_complete,	},};static int __init ipv6_offload_init(void){ 	if (tcpv6_offload_init() < 0)		pr_crit("%s: Cannot add TCP protocol offload\n", __func__);	if (ipv6_exthdrs_offload_init() < 0)		pr_crit("%s: Cannot add EXTHDRS protocol offload\n", __func__); 	net_hotdata.ipv6_packet_offload = (struct packet_offload) {		.type = cpu_to_be16(ETH_P_IPV6),		.callbacks = {			.gso_segment = ipv6_gso_segment,			.gro_receive = ipv6_gro_receive,			.gro_complete = ipv6_gro_complete,		},	};	dev_add_offload(&net_hotdata.ipv6_packet_offload); 	inet_add_offload(&sit_offload, IPPROTO_IPV6);	inet6_add_offload(&ip6ip6_offload, IPPROTO_IPV6);	inet6_add_offload(&ip4ip6_offload, IPPROTO_IPIP); 	return 0;} fs_initcall(ipv6_offload_init);