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Commit 8052ba29 authored by Alex Gartrell's avatar Alex Gartrell Committed by Simon Horman
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ipvs: support ipv4 in ipv6 and ipv6 in ipv4 tunnel forwarding 



Pull the common logic for preparing an skb to prepend the header into a
single function and then set fields such that they can be used in either
case (generalize tos and tclass to dscp, hop_limit and ttl to ttl, etc)

Signed-off-by: default avatarAlex Gartrell <agartrell@fb.com>
Acked-by: default avatarJulian Anastasov <ja@ssi.bg>
Signed-off-by: default avatarSimon Horman <horms@verge.net.au>
parent c63e4de2

net/netfilter/ipvs/ip_vs_conn.c

+10 −2
Original line number Diff line number Diff line
@@ -488,6 +488,11 @@ static inline void ip_vs_bind_xmit(struct ip_vs_conn *cp) 
		break;



	case IP_VS_CONN_F_TUNNEL:

#ifdef CONFIG_IP_VS_IPV6

		if (cp->daf == AF_INET6)

			cp->packet_xmit = ip_vs_tunnel_xmit_v6;

		else

#endif

			cp->packet_xmit = ip_vs_tunnel_xmit;

		break;
@@ -514,7 +519,10 @@ static inline void ip_vs_bind_xmit_v6(struct ip_vs_conn *cp) 
		break;



	case IP_VS_CONN_F_TUNNEL:

		if (cp->daf == AF_INET6)

			cp->packet_xmit = ip_vs_tunnel_xmit_v6;

		else

			cp->packet_xmit = ip_vs_tunnel_xmit;

		break;



	case IP_VS_CONN_F_DROUTE:

net/netfilter/ipvs/ip_vs_xmit.c

+107 −41
Original line number Diff line number Diff line
@@ -824,6 +824,81 @@ ip_vs_nat_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, 
}

#endif



/* When forwarding a packet, we must ensure that we've got enough headroom

 * for the encapsulation packet in the skb.  This also gives us an

 * opportunity to figure out what the payload_len, dsfield, ttl, and df

 * values should be, so that we won't need to look at the old ip header

 * again

 */

static struct sk_buff *

ip_vs_prepare_tunneled_skb(struct sk_buff *skb, int skb_af,

			   unsigned int max_headroom, __u8 *next_protocol,

			   __u32 *payload_len, __u8 *dsfield, __u8 *ttl,

			   __be16 *df)

{

	struct sk_buff *new_skb = NULL;

	struct iphdr *old_iph = NULL;

#ifdef CONFIG_IP_VS_IPV6

	struct ipv6hdr *old_ipv6h = NULL;

#endif



	if (skb_headroom(skb) < max_headroom || skb_cloned(skb)) {

		new_skb = skb_realloc_headroom(skb, max_headroom);

		if (!new_skb)

			goto error;

		consume_skb(skb);

		skb = new_skb;

	}



#ifdef CONFIG_IP_VS_IPV6

	if (skb_af == AF_INET6) {

		old_ipv6h = ipv6_hdr(skb);

		*next_protocol = IPPROTO_IPV6;

		if (payload_len)

			*payload_len =

				ntohs(old_ipv6h->payload_len) +

				sizeof(*old_ipv6h);

		*dsfield = ipv6_get_dsfield(old_ipv6h);

		*ttl = old_ipv6h->hop_limit;

		if (df)

			*df = 0;

	} else

#endif

	{

		old_iph = ip_hdr(skb);

		/* Copy DF, reset fragment offset and MF */

		if (df)

			*df = (old_iph->frag_off & htons(IP_DF));

		*next_protocol = IPPROTO_IPIP;



		/* fix old IP header checksum */

		ip_send_check(old_iph);

		*dsfield = ipv4_get_dsfield(old_iph);

		*ttl = old_iph->ttl;

		if (payload_len)

			*payload_len = ntohs(old_iph->tot_len);

	}



	return skb;

error:

	kfree_skb(skb);

	return ERR_PTR(-ENOMEM);

}



static inline int __tun_gso_type_mask(int encaps_af, int orig_af)

{

	if (encaps_af == AF_INET) {

		if (orig_af == AF_INET)

			return SKB_GSO_IPIP;



		return SKB_GSO_SIT;

	}



	/* GSO: we need to provide proper SKB_GSO_ value for IPv6:

	 * SKB_GSO_SIT/IPV6

	 */

	return 0;

}



/*

 *   IP Tunneling transmitter
@@ -852,9 +927,11 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp, 
	struct rtable *rt;			/* Route to the other host */

	__be32 saddr;				/* Source for tunnel */

	struct net_device *tdev;		/* Device to other host */

	struct iphdr  *old_iph = ip_hdr(skb);

	u8     tos = old_iph->tos;

	__be16 df;

	__u8 next_protocol = 0;

	__u8 dsfield = 0;

	__u8 ttl = 0;

	__be16 df = 0;

	__be16 *dfp = NULL;

	struct iphdr  *iph;			/* Our new IP header */

	unsigned int max_headroom;		/* The extra header space needed */

	int ret, local;
@@ -877,29 +954,21 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp, 
	rt = skb_rtable(skb);

	tdev = rt->dst.dev;



	/* Copy DF, reset fragment offset and MF */

	df = sysctl_pmtu_disc(ipvs) ? old_iph->frag_off & htons(IP_DF) : 0;



	/*

	 * Okay, now see if we can stuff it in the buffer as-is.

	 */

	max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct iphdr);



	if (skb_headroom(skb) < max_headroom || skb_cloned(skb)) {

		struct sk_buff *new_skb =

			skb_realloc_headroom(skb, max_headroom);



		if (!new_skb)

	/* We only care about the df field if sysctl_pmtu_disc(ipvs) is set */

	dfp = sysctl_pmtu_disc(ipvs) ? &df : NULL;

	skb = ip_vs_prepare_tunneled_skb(skb, cp->af, max_headroom,

					 &next_protocol, NULL, &dsfield,

					 &ttl, dfp);

	if (IS_ERR(skb))

		goto tx_error;

		consume_skb(skb);

		skb = new_skb;

		old_iph = ip_hdr(skb);

	}



	/* fix old IP header checksum */

	ip_send_check(old_iph);



	skb = iptunnel_handle_offloads(skb, false, SKB_GSO_IPIP);

	skb = iptunnel_handle_offloads(

		skb, false, __tun_gso_type_mask(AF_INET, cp->af));

	if (IS_ERR(skb))

		goto tx_error;
@@ -916,11 +985,11 @@ ip_vs_tunnel_xmit(struct sk_buff *skb, struct ip_vs_conn *cp, 
	iph->version		=	4;

	iph->ihl		=	sizeof(struct iphdr)>>2;

	iph->frag_off		=	df;

	iph->protocol		=	IPPROTO_IPIP;

	iph->tos		=	tos;

	iph->protocol		=	next_protocol;

	iph->tos		=	dsfield;

	iph->daddr		=	cp->daddr.ip;

	iph->saddr		=	saddr;

	iph->ttl		=	old_iph->ttl;

	iph->ttl		=	ttl;

	ip_select_ident(skb, NULL);



	/* Another hack: avoid icmp_send in ip_fragment */
@@ -953,7 +1022,10 @@ ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, 
	struct rt6_info *rt;		/* Route to the other host */

	struct in6_addr saddr;		/* Source for tunnel */

	struct net_device *tdev;	/* Device to other host */

	struct ipv6hdr  *old_iph = ipv6_hdr(skb);

	__u8 next_protocol = 0;

	__u32 payload_len = 0;

	__u8 dsfield = 0;

	__u8 ttl = 0;

	struct ipv6hdr  *iph;		/* Our new IP header */

	unsigned int max_headroom;	/* The extra header space needed */

	int ret, local;
@@ -981,19 +1053,14 @@ ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, 
	 */

	max_headroom = LL_RESERVED_SPACE(tdev) + sizeof(struct ipv6hdr);



	if (skb_headroom(skb) < max_headroom || skb_cloned(skb)) {

		struct sk_buff *new_skb =

			skb_realloc_headroom(skb, max_headroom);



		if (!new_skb)

	skb = ip_vs_prepare_tunneled_skb(skb, cp->af, max_headroom,

					 &next_protocol, &payload_len,

					 &dsfield, &ttl, NULL);

	if (IS_ERR(skb))

		goto tx_error;

		consume_skb(skb);

		skb = new_skb;

		old_iph = ipv6_hdr(skb);

	}



	/* GSO: we need to provide proper SKB_GSO_ value for IPv6 */

	skb = iptunnel_handle_offloads(skb, false, 0); /* SKB_GSO_SIT/IPV6 */

	skb = iptunnel_handle_offloads(

		skb, false, __tun_gso_type_mask(AF_INET6, cp->af));

	if (IS_ERR(skb))

		goto tx_error;
@@ -1008,14 +1075,13 @@ ip_vs_tunnel_xmit_v6(struct sk_buff *skb, struct ip_vs_conn *cp, 
	 */

	iph			=	ipv6_hdr(skb);

	iph->version		=	6;

	iph->nexthdr		=	IPPROTO_IPV6;

	iph->payload_len	=	old_iph->payload_len;

	be16_add_cpu(&iph->payload_len, sizeof(*old_iph));

	iph->nexthdr		=	next_protocol;

	iph->payload_len	=	htons(payload_len);

	memset(&iph->flow_lbl, 0, sizeof(iph->flow_lbl));

	ipv6_change_dsfield(iph, 0, ipv6_get_dsfield(old_iph));

	ipv6_change_dsfield(iph, 0, dsfield);

	iph->daddr = cp->daddr.in6;

	iph->saddr = saddr;

	iph->hop_limit		=	old_iph->hop_limit;

	iph->hop_limit		=	ttl;



	/* Another hack: avoid icmp_send in ip_fragment */

	skb->ignore_df = 1;