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Commit 308edfdf authored by Tom Herbert's avatar Tom Herbert Committed by David S. Miller
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gre6: Cleanup GREv6 receive path, call common GRE functions



- Create gre_rcv function. This calls gre_parse_header and ip6gre_rcv.
  - Call ip6_tnl_rcv. Doing this and using gre_parse_header eliminates
    most of the code in ip6gre_rcv.

Signed-off-by: default avatarTom Herbert <tom@herbertland.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 95f5c64c
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+23 −117
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@
#include <net/ip6_fib.h>
#include <net/ip6_route.h>
#include <net/ip6_tunnel.h>
#include <net/gre.h>


static bool log_ecn_error = true;
@@ -443,137 +444,40 @@ static void ip6gre_err(struct sk_buff *skb, struct inet6_skb_parm *opt,
	t->err_time = jiffies;
}

static int ip6gre_rcv(struct sk_buff *skb)
static int ip6gre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
{
	const struct ipv6hdr *ipv6h;
	u8     *h;
	__be16    flags;
	__sum16   csum = 0;
	__be32 key = 0;
	u32    seqno = 0;
	struct ip6_tnl *tunnel;
	int    offset = 4;
	__be16 gre_proto;
	int err;

	if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
		goto drop;

	ipv6h = ipv6_hdr(skb);
	h = skb->data;
	flags = *(__be16 *)h;

	if (flags&(GRE_CSUM|GRE_KEY|GRE_ROUTING|GRE_SEQ|GRE_VERSION)) {
		/* - Version must be 0.
		   - We do not support routing headers.
		 */
		if (flags&(GRE_VERSION|GRE_ROUTING))
			goto drop;

		if (flags&GRE_CSUM) {
			csum = skb_checksum_simple_validate(skb);
			offset += 4;
		}
		if (flags&GRE_KEY) {
			key = *(__be32 *)(h + offset);
			offset += 4;
		}
		if (flags&GRE_SEQ) {
			seqno = ntohl(*(__be32 *)(h + offset));
			offset += 4;
		}
	}

	gre_proto = *(__be16 *)(h + 2);

	tunnel = ip6gre_tunnel_lookup(skb->dev,
					  &ipv6h->saddr, &ipv6h->daddr, key,
					  gre_proto);
				      &ipv6h->saddr, &ipv6h->daddr, tpi->key,
				      tpi->proto);
	if (tunnel) {
		struct pcpu_sw_netstats *tstats;
		ip6_tnl_rcv(tunnel, skb, tpi, NULL, false);

		if (!xfrm6_policy_check(NULL, XFRM_POLICY_IN, skb))
			goto drop;

		if (!ip6_tnl_rcv_ctl(tunnel, &ipv6h->daddr, &ipv6h->saddr)) {
			tunnel->dev->stats.rx_dropped++;
			goto drop;
		return PACKET_RCVD;
	}

		skb->protocol = gre_proto;
		/* WCCP version 1 and 2 protocol decoding.
		 * - Change protocol to IPv6
		 * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
		 */
		if (flags == 0 && gre_proto == htons(ETH_P_WCCP)) {
			skb->protocol = htons(ETH_P_IPV6);
			if ((*(h + offset) & 0xF0) != 0x40)
				offset += 4;
	return PACKET_REJECT;
}

		skb->mac_header = skb->network_header;
		__pskb_pull(skb, offset);
		skb_postpull_rcsum(skb, skb_transport_header(skb), offset);

		if (((flags&GRE_CSUM) && csum) ||
		    (!(flags&GRE_CSUM) && tunnel->parms.i_flags&GRE_CSUM)) {
			tunnel->dev->stats.rx_crc_errors++;
			tunnel->dev->stats.rx_errors++;
			goto drop;
		}
		if (tunnel->parms.i_flags&GRE_SEQ) {
			if (!(flags&GRE_SEQ) ||
			    (tunnel->i_seqno &&
					(s32)(seqno - tunnel->i_seqno) < 0)) {
				tunnel->dev->stats.rx_fifo_errors++;
				tunnel->dev->stats.rx_errors++;
				goto drop;
			}
			tunnel->i_seqno = seqno + 1;
		}
static int gre_rcv(struct sk_buff *skb)
{
	struct tnl_ptk_info tpi;
	bool csum_err = false;
	int hdr_len;

		/* Warning: All skb pointers will be invalidated! */
		if (tunnel->dev->type == ARPHRD_ETHER) {
			if (!pskb_may_pull(skb, ETH_HLEN)) {
				tunnel->dev->stats.rx_length_errors++;
				tunnel->dev->stats.rx_errors++;
	if (gre_parse_header(skb, &tpi, &csum_err, &hdr_len) < 0)
		goto drop;
			}

			ipv6h = ipv6_hdr(skb);
			skb->protocol = eth_type_trans(skb, tunnel->dev);
			skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
		}

		__skb_tunnel_rx(skb, tunnel->dev, tunnel->net);

		skb_reset_network_header(skb);

		err = IP6_ECN_decapsulate(ipv6h, skb);
		if (unlikely(err)) {
			if (log_ecn_error)
				net_info_ratelimited("non-ECT from %pI6 with dsfield=%#x\n",
						     &ipv6h->saddr,
						     ipv6_get_dsfield(ipv6h));
			if (err > 1) {
				++tunnel->dev->stats.rx_frame_errors;
				++tunnel->dev->stats.rx_errors;
	if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
		goto drop;
			}
		}

		tstats = this_cpu_ptr(tunnel->dev->tstats);
		u64_stats_update_begin(&tstats->syncp);
		tstats->rx_packets++;
		tstats->rx_bytes += skb->len;
		u64_stats_update_end(&tstats->syncp);

		netif_rx(skb);

	if (ip6gre_rcv(skb, &tpi) == PACKET_RCVD)
		return 0;
	}
	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);

	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_PORT_UNREACH, 0);
drop:
	kfree_skb(skb);
	return 0;
@@ -1075,6 +979,8 @@ static int ip6gre_tunnel_ioctl(struct net_device *dev,
	struct net *net = t->net;
	struct ip6gre_net *ign = net_generic(net, ip6gre_net_id);

	memset(&p1, 0, sizeof(p1));

	switch (cmd) {
	case SIOCGETTUNNEL:
		if (dev == ign->fb_tunnel_dev) {
@@ -1318,7 +1224,7 @@ static void ip6gre_fb_tunnel_init(struct net_device *dev)


static struct inet6_protocol ip6gre_protocol __read_mostly = {
	.handler     = ip6gre_rcv,
	.handler     = gre_rcv,
	.err_handler = ip6gre_err,
	.flags       = INET6_PROTO_NOPOLICY|INET6_PROTO_FINAL,
};