PPTP: PPP over IPv4 (Point-to-Point Tunneling Protocol)

PPP: introduce "pptp" module which implements point-to-point tunneling protocol using pppox framework
NET: introduce the "gre" module for demultiplexing GRE packets on version criteria
     (required to pptp and ip_gre may coexists)
NET: ip_gre: update to use the "gre" module

This patch introduces then pptp support to the linux kernel which
dramatically speeds up pptp vpn connections and decreases cpu usage in
comparison of existing user-space implementation
(poptop/pptpclient). There is accel-pptp project
(https://sourceforge.net/projects/accel-pptp/) to utilize this module,
it contains plugin for pppd to use pptp in client-mode and modified
pptpd (poptop) to build high-performance pptp NAS.

There was many changes from initial submitted patch, most important are:
1. using rcu instead of read-write locks
2. using static bitmap instead of dynamically allocated
3. using vmalloc for memory allocation instead of BITS_PER_LONG + __get_free_pages
4. fixed many coding style issues
Thanks to Eric Dumazet.

Signed-off-by: Dmitry Kozlov <xeb@mail.ru>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 7 deletions

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 945b20a5ad50..85176895495a 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -44,6 +44,7 @@
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 #include <net/rtnetlink.h>
+#include <net/gre.h>
 
 #ifdef CONFIG_IPV6
 #include <net/ipv6.h>
@@ -1278,10 +1279,9 @@ static void ipgre_fb_tunnel_init(struct net_device *dev)
 }
 
 
-static const struct net_protocol ipgre_protocol = {
-        .handler        =       ipgre_rcv,
-        .err_handler    =       ipgre_err,
-        .netns_ok       =       1,
+static const struct gre_protocol ipgre_protocol = {
+        .handler     = ipgre_rcv,
+        .err_handler = ipgre_err,
 };
 
 static void ipgre_destroy_tunnels(struct ipgre_net *ign, struct list_head *head)
@@ -1663,7 +1663,7 @@ static int __init ipgre_init(void)
         if (err < 0)
                 return err;
 
-        err = inet_add_protocol(&ipgre_protocol, IPPROTO_GRE);
+        err = gre_add_protocol(&ipgre_protocol, GREPROTO_CISCO);
         if (err < 0) {
                 printk(KERN_INFO "ipgre init: can't add protocol\n");
                 goto add_proto_failed;
@@ -1683,7 +1683,7 @@ out:
 tap_ops_failed:
         rtnl_link_unregister(&ipgre_link_ops);
 rtnl_link_failed:
-        inet_del_protocol(&ipgre_protocol, IPPROTO_GRE);
+        gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO);
 add_proto_failed:
         unregister_pernet_device(&ipgre_net_ops);
         goto out;
@@ -1693,7 +1693,7 @@ static void __exit ipgre_fini(void)
 {
         rtnl_link_unregister(&ipgre_tap_ops);
         rtnl_link_unregister(&ipgre_link_ops);
-        if (inet_del_protocol(&ipgre_protocol, IPPROTO_GRE) < 0)
+        if (gre_del_protocol(&ipgre_protocol, GREPROTO_CISCO) < 0)
                 printk(KERN_INFO "ipgre close: can't remove protocol\n");
         unregister_pernet_device(&ipgre_net_ops);
 }