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: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index ca5a2c5675c5c28bbf29a1519bed344604841505..9b33745761ca770c9e8869e7364d635d5e06bb4d 100644 (file)
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -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;
-
-               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;
-               }
-
-               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;
-               }
+               ip6_tnl_rcv(tunnel, skb, tpi, NULL, false);
 
-               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;
-               }
-
-               /* 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++;
-                               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);
+               return PACKET_RCVD;
+       }
 
-               skb_reset_network_header(skb);
+       return PACKET_REJECT;
+}
 
-               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;
-                               goto drop;
-                       }
-               }
+static int gre_rcv(struct sk_buff *skb)
+{
+       struct tnl_ptk_info tpi;
+       bool csum_err = false;
+       int hdr_len;
 
-               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);
+       if (gre_parse_header(skb, &tpi, &csum_err, &hdr_len) < 0)
+               goto drop;
 
-               netif_rx(skb);
+       if (iptunnel_pull_header(skb, hdr_len, tpi.proto, false))
+               goto drop;
 
+       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,
 };