gre: Remove support for sharing GRE protocol hook.
authorPravin B Shelar <pshelar@nicira.com>
Sat, 8 Aug 2015 06:51:52 +0000 (23:51 -0700)
committerDavid S. Miller <davem@davemloft.net>
Mon, 10 Aug 2015 21:03:54 +0000 (14:03 -0700)
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>
include/net/gre.h
net/ipv4/gre_demux.c
net/ipv4/ip_gre.c

index e3e08459bf6721936383c51995118d6f975a9516..97eafdc47eea118f6122b4a51a790d93a3830f86 100644 (file)
@@ -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
index 77562e0ac66b21cc7bc4613ae4f254bd67c18814..d9c552a721fcb19f17ac02c1972be935d8f2f11e 100644 (file)
@@ -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);
 }
 
index 49d140200d0374b4aa78a3ee536f946c35570e39..fb44d693796efc04535dd2c51cebc9081dd9bbfb 100644 (file)
@@ -123,8 +123,127 @@ static int ipgre_tunnel_init(struct net_device *dev);
 static int ipgre_net_id __read_mostly;
 static int gre_tap_net_id __read_mostly;
 
-static int ipgre_err(struct sk_buff *skb, u32 info,
-                    const struct tnl_ptk_info *tpi)
+static 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 __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 __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;
+}
+
+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 void ipgre_err(struct sk_buff *skb, u32 info,
+                     const struct tnl_ptk_info *tpi)
 {
 
        /* All the routers (except for Linux) return only
@@ -150,14 +269,14 @@ static int ipgre_err(struct sk_buff *skb, u32 info,
        switch (type) {
        default:
        case ICMP_PARAMETERPROB:
-               return PACKET_RCVD;
+               return;
 
        case ICMP_DEST_UNREACH:
                switch (code) {
                case ICMP_SR_FAILED:
                case ICMP_PORT_UNREACH:
                        /* Impossible event. */
-                       return PACKET_RCVD;
+                       return;
                default:
                        /* All others are translated to HOST_UNREACH.
                           rfc2003 contains "deep thoughts" about NET_UNREACH,
@@ -166,9 +285,10 @@ static int ipgre_err(struct sk_buff *skb, u32 info,
                        break;
                }
                break;
+
        case ICMP_TIME_EXCEEDED:
                if (code != ICMP_EXC_TTL)
-                       return PACKET_RCVD;
+                       return;
                break;
 
        case ICMP_REDIRECT:
@@ -185,21 +305,60 @@ static int ipgre_err(struct sk_buff *skb, u32 info,
                             iph->daddr, iph->saddr, tpi->key);
 
        if (!t)
-               return PACKET_REJECT;
+               return;
 
        if (t->parms.iph.daddr == 0 ||
            ipv4_is_multicast(t->parms.iph.daddr))
-               return PACKET_RCVD;
+               return;
 
        if (t->parms.iph.ttl == 0 && type == ICMP_TIME_EXCEEDED)
-               return PACKET_RCVD;
+               return;
 
        if (time_before(jiffies, t->err_time + IPTUNNEL_ERR_TIMEO))
                t->err_count++;
        else
                t->err_count = 1;
        t->err_time = jiffies;
-       return PACKET_RCVD;
+}
+
+static void gre_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;
+
+       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;
+       }
+
+       ipgre_err(skb, info, &tpi);
 }
 
 static __be64 key_to_tunnel_id(__be32 key)
@@ -268,6 +427,31 @@ static int ipgre_rcv(struct sk_buff *skb, const struct tnl_ptk_info *tpi)
        return PACKET_REJECT;
 }
 
+static int gre_rcv(struct sk_buff *skb)
+{
+       struct tnl_ptk_info tpi;
+       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;
+
+       if (ipgre_rcv(skb, &tpi) == PACKET_RCVD)
+               return 0;
+
+       icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);
+drop:
+       kfree_skb(skb);
+       return 0;
+}
+
 static void build_header(struct sk_buff *skb, int hdr_len, __be16 flags,
                         __be16 proto, __be32 key, __be32 seq)
 {
@@ -684,10 +868,9 @@ static int ipgre_tunnel_init(struct net_device *dev)
        return ip_tunnel_init(dev);
 }
 
-static struct gre_cisco_protocol ipgre_protocol = {
-       .handler        = ipgre_rcv,
-       .err_handler    = ipgre_err,
-       .priority       = 0,
+static const struct gre_protocol ipgre_protocol = {
+       .handler     = gre_rcv,
+       .err_handler = gre_err,
 };
 
 static int __net_init ipgre_init_net(struct net *net)
@@ -1080,7 +1263,7 @@ static int __init ipgre_init(void)
        if (err < 0)
                goto pnet_tap_faied;
 
-       err = gre_cisco_register(&ipgre_protocol);
+       err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
        if (err < 0) {
                pr_info("%s: can't add protocol\n", __func__);
                goto add_proto_failed;
@@ -1099,7 +1282,7 @@ static int __init ipgre_init(void)
 tap_ops_failed:
        rtnl_link_unregister(&ipgre_link_ops);
 rtnl_link_failed:
-       gre_cisco_unregister(&ipgre_protocol);
+       gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
 add_proto_failed:
        unregister_pernet_device(&ipgre_tap_net_ops);
 pnet_tap_faied:
@@ -1111,7 +1294,7 @@ static void __exit ipgre_fini(void)
 {
        rtnl_link_unregister(&ipgre_tap_ops);
        rtnl_link_unregister(&ipgre_link_ops);
-       gre_cisco_unregister(&ipgre_protocol);
+       gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
        unregister_pernet_device(&ipgre_tap_net_ops);
        unregister_pernet_device(&ipgre_net_ops);
 }