gre: Remove support for sharing GRE protocol hook.

Support for sharing GREPROTO_CISCO port was added so that
OVS gre port and kernel GRE devices can co-exist. After
flow-based tunneling patches OVS GRE protocol processing
is completely moved to ip_gre module. so there is no need
for GRE protocol hook. Following patch consolidates
GRE protocol related functions into ip_gre module.

Signed-off-by: Pravin B Shelar <pshelar@nicira.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/gre.h b/include/net/gre.h
index e3e0845..97eafdc 100644 (file)
--- a/include/net/gre.h
+++ b/include/net/gre.h
@@ -4,6 +4,12 @@
 #include <linux/skbuff.h>
 #include <net/ip_tunnels.h>
 
+struct gre_base_hdr {
+       __be16 flags;
+       __be16 protocol;
+};
+#define GRE_HEADER_SECTION 4
+
 #define GREPROTO_CISCO         0
 #define GREPROTO_PPTP          1
 #define GREPROTO_MAX           2
@@ -14,83 +20,9 @@ struct gre_protocol {
        void (*err_handler)(struct sk_buff *skb, u32 info);
 };
 
-struct gre_base_hdr {
-       __be16 flags;
-       __be16 protocol;
-};
-#define GRE_HEADER_SECTION 4
-
 int gre_add_protocol(const struct gre_protocol *proto, u8 version);
 int gre_del_protocol(const struct gre_protocol *proto, u8 version);
 
-struct gre_cisco_protocol {
-       int (*handler)(struct sk_buff *skb, const struct tnl_ptk_info *tpi);
-       int (*err_handler)(struct sk_buff *skb, u32 info,
-                          const struct tnl_ptk_info *tpi);
-       u8 priority;
-};
-
-int gre_cisco_register(struct gre_cisco_protocol *proto);
-int gre_cisco_unregister(struct gre_cisco_protocol *proto);
-
 struct net_device *gretap_fb_dev_create(struct net *net, const char *name,
                                       u8 name_assign_type);
-
-static inline int ip_gre_calc_hlen(__be16 o_flags)
-{
-       int addend = 4;
-
-       if (o_flags&TUNNEL_CSUM)
-               addend += 4;
-       if (o_flags&TUNNEL_KEY)
-               addend += 4;
-       if (o_flags&TUNNEL_SEQ)
-               addend += 4;
-       return addend;
-}
-
-static inline __be16 gre_flags_to_tnl_flags(__be16 flags)
-{
-       __be16 tflags = 0;
-
-       if (flags & GRE_CSUM)
-               tflags |= TUNNEL_CSUM;
-       if (flags & GRE_ROUTING)
-               tflags |= TUNNEL_ROUTING;
-       if (flags & GRE_KEY)
-               tflags |= TUNNEL_KEY;
-       if (flags & GRE_SEQ)
-               tflags |= TUNNEL_SEQ;
-       if (flags & GRE_STRICT)
-               tflags |= TUNNEL_STRICT;
-       if (flags & GRE_REC)
-               tflags |= TUNNEL_REC;
-       if (flags & GRE_VERSION)
-               tflags |= TUNNEL_VERSION;
-
-       return tflags;
-}
-
-static inline __be16 tnl_flags_to_gre_flags(__be16 tflags)
-{
-       __be16 flags = 0;
-
-       if (tflags & TUNNEL_CSUM)
-               flags |= GRE_CSUM;
-       if (tflags & TUNNEL_ROUTING)
-               flags |= GRE_ROUTING;
-       if (tflags & TUNNEL_KEY)
-               flags |= GRE_KEY;
-       if (tflags & TUNNEL_SEQ)
-               flags |= GRE_SEQ;
-       if (tflags & TUNNEL_STRICT)
-               flags |= GRE_STRICT;
-       if (tflags & TUNNEL_REC)
-               flags |= GRE_REC;
-       if (tflags & TUNNEL_VERSION)
-               flags |= GRE_VERSION;
-
-       return flags;
-}
-
 #endif

diff --git a/net/ipv4/gre_demux.c b/net/ipv4/gre_demux.c
index 77562e0..d9c552a 100644 (file)
--- a/net/ipv4/gre_demux.c
+++ b/net/ipv4/gre_demux.c
@@ -31,7 +31,6 @@
 #include <net/xfrm.h>
 
 static const struct gre_protocol __rcu *gre_proto[GREPROTO_MAX] __read_mostly;
-static struct gre_cisco_protocol __rcu *gre_cisco_proto_list[GRE_IP_PROTO_MAX];
 
 int gre_add_protocol(const struct gre_protocol *proto, u8 version)
 {
@@ -61,163 +60,6 @@ int gre_del_protocol(const struct gre_protocol *proto, u8 version)
 }
 EXPORT_SYMBOL_GPL(gre_del_protocol);
 
-static int parse_gre_header(struct sk_buff *skb, struct tnl_ptk_info *tpi,
-                           bool *csum_err)
-{
-       const struct gre_base_hdr *greh;
-       __be32 *options;
-       int hdr_len;
-
-       if (unlikely(!pskb_may_pull(skb, sizeof(struct gre_base_hdr))))
-               return -EINVAL;
-
-       greh = (struct gre_base_hdr *)skb_transport_header(skb);
-       if (unlikely(greh->flags & (GRE_VERSION | GRE_ROUTING)))
-               return -EINVAL;
-
-       tpi->flags = gre_flags_to_tnl_flags(greh->flags);
-       hdr_len = ip_gre_calc_hlen(tpi->flags);
-
-       if (!pskb_may_pull(skb, hdr_len))
-               return -EINVAL;
-
-       greh = (struct gre_base_hdr *)skb_transport_header(skb);
-       tpi->proto = greh->protocol;
-
-       options = (__be32 *)(greh + 1);
-       if (greh->flags & GRE_CSUM) {
-               if (skb_checksum_simple_validate(skb)) {
-                       *csum_err = true;
-                       return -EINVAL;
-               }
-
-               skb_checksum_try_convert(skb, IPPROTO_GRE, 0,
-                                        null_compute_pseudo);
-
-               options++;
-       }
-
-       if (greh->flags & GRE_KEY) {
-               tpi->key = *options;
-               options++;
-       } else
-               tpi->key = 0;
-
-       if (unlikely(greh->flags & GRE_SEQ)) {
-               tpi->seq = *options;
-               options++;
-       } else
-               tpi->seq = 0;
-
-       /* WCCP version 1 and 2 protocol decoding.
-        * - Change protocol to IP
-        * - When dealing with WCCPv2, Skip extra 4 bytes in GRE header
-        */
-       if (greh->flags == 0 && tpi->proto == htons(ETH_P_WCCP)) {
-               tpi->proto = htons(ETH_P_IP);
-               if ((*(u8 *)options & 0xF0) != 0x40) {
-                       hdr_len += 4;
-                       if (!pskb_may_pull(skb, hdr_len))
-                               return -EINVAL;
-               }
-       }
-
-       return iptunnel_pull_header(skb, hdr_len, tpi->proto);
-}
-
-static int gre_cisco_rcv(struct sk_buff *skb)
-{
-       struct tnl_ptk_info tpi;
-       int i;
-       bool csum_err = false;
-
-#ifdef CONFIG_NET_IPGRE_BROADCAST
-       if (ipv4_is_multicast(ip_hdr(skb)->daddr)) {
-               /* Looped back packet, drop it! */
-               if (rt_is_output_route(skb_rtable(skb)))
-                       goto drop;
-       }
-#endif
-
-       if (parse_gre_header(skb, &tpi, &csum_err) < 0)
-               goto drop;
-
-       rcu_read_lock();
-       for (i = 0; i < GRE_IP_PROTO_MAX; i++) {
-               struct gre_cisco_protocol *proto;
-               int ret;
-
-               proto = rcu_dereference(gre_cisco_proto_list[i]);
-               if (!proto)
-                       continue;
-               ret = proto->handler(skb, &tpi);
-               if (ret == PACKET_RCVD) {
-                       rcu_read_unlock();
-                       return 0;
-               }
-       }
-       rcu_read_unlock();
-
-       icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
-drop:
-       kfree_skb(skb);
-       return 0;
-}
-
-static void gre_cisco_err(struct sk_buff *skb, u32 info)
-{
-       /* All the routers (except for Linux) return only
-        * 8 bytes of packet payload. It means, that precise relaying of
-        * ICMP in the real Internet is absolutely infeasible.
-        *
-        * Moreover, Cisco "wise men" put GRE key to the third word
-        * in GRE header. It makes impossible maintaining even soft
-        * state for keyed
-        * GRE tunnels with enabled checksum. Tell them "thank you".
-        *
-        * Well, I wonder, rfc1812 was written by Cisco employee,
-        * what the hell these idiots break standards established
-        * by themselves???
-        */
-
-       const int type = icmp_hdr(skb)->type;
-       const int code = icmp_hdr(skb)->code;
-       struct tnl_ptk_info tpi;
-       bool csum_err = false;
-       int i;
-
-       if (parse_gre_header(skb, &tpi, &csum_err)) {
-               if (!csum_err)          /* ignore csum errors. */
-                       return;
-       }
-
-       if (type == ICMP_DEST_UNREACH && code == ICMP_FRAG_NEEDED) {
-               ipv4_update_pmtu(skb, dev_net(skb->dev), info,
-                               skb->dev->ifindex, 0, IPPROTO_GRE, 0);
-               return;
-       }
-       if (type == ICMP_REDIRECT) {
-               ipv4_redirect(skb, dev_net(skb->dev), skb->dev->ifindex, 0,
-                               IPPROTO_GRE, 0);
-               return;
-       }
-
-       rcu_read_lock();
-       for (i = 0; i < GRE_IP_PROTO_MAX; i++) {
-               struct gre_cisco_protocol *proto;
-
-               proto = rcu_dereference(gre_cisco_proto_list[i]);
-               if (!proto)
-                       continue;
-
-               if (proto->err_handler(skb, info, &tpi) == PACKET_RCVD)
-                       goto out;
-
-       }
-out:
-       rcu_read_unlock();
-}
-
 static int gre_rcv(struct sk_buff *skb)
 {
        const struct gre_protocol *proto;
@@ -268,60 +110,19 @@ static const struct net_protocol net_gre_protocol = {
        .netns_ok    = 1,
 };
 
-static const struct gre_protocol ipgre_protocol = {
-       .handler     = gre_cisco_rcv,
-       .err_handler = gre_cisco_err,
-};
-
-int gre_cisco_register(struct gre_cisco_protocol *newp)
-{
-       struct gre_cisco_protocol **proto = (struct gre_cisco_protocol **)
-                                           &gre_cisco_proto_list[newp->priority];
-
-       return (cmpxchg(proto, NULL, newp) == NULL) ? 0 : -EBUSY;
-}
-EXPORT_SYMBOL_GPL(gre_cisco_register);
-
-int gre_cisco_unregister(struct gre_cisco_protocol *del_proto)
-{
-       struct gre_cisco_protocol **proto = (struct gre_cisco_protocol **)
-                                           &gre_cisco_proto_list[del_proto->priority];
-       int ret;
-
-       ret = (cmpxchg(proto, del_proto, NULL) == del_proto) ? 0 : -EINVAL;
-
-       if (ret)
-               return ret;
-
-       synchronize_net();
-       return 0;
-}
-EXPORT_SYMBOL_GPL(gre_cisco_unregister);
-
 static int __init gre_init(void)
 {
        pr_info("GRE over IPv4 demultiplexor driver\n");
 
        if (inet_add_protocol(&net_gre_protocol, IPPROTO_GRE) < 0) {
                pr_err("can't add protocol\n");
-               goto err;
+               return -EAGAIN;
        }
-
-       if (gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0) {
-               pr_info("%s: can't add ipgre handler\n", __func__);
-               goto err_gre;
-       }
-
        return 0;
-err_gre:
-       inet_del_protocol(&net_gre_protocol, IPPROTO_GRE);
-err:
-       return -EAGAIN;
 }
 
 static void __exit gre_exit(void)
 {
-       gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
        inet_del_protocol(&net_gre_protocol, IPPROTO_GRE);
 }
 

diff --cc net/ipv4/ip_gre.c
Simple merge