xfrm: select sane defaults for xfrm[4|6] gc_thresh

[linux-block.git] / net / ipv6 / xfrm6_policy.c

diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index b4b16a43f2771bd62558a2cd8ca3af60b0d99808..611cffcf554fba797d67a45c68168ffd5e78629a 100644 (file)
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -157,7 +157,8 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
        ipv6_addr_copy(&fl->fl6_dst, reverse ? &hdr->saddr : &hdr->daddr);
        ipv6_addr_copy(&fl->fl6_src, reverse ? &hdr->daddr : &hdr->saddr);
 
-       while (pskb_may_pull(skb, nh + offset + 1 - skb->data)) {
+       while (nh + offset + 1 < skb->data ||
+              pskb_may_pull(skb, nh + offset + 1 - skb->data)) {
                nh = skb_network_header(skb);
                exthdr = (struct ipv6_opt_hdr *)(nh + offset);
 
@@ -177,7 +178,8 @@ _decode_session6(struct sk_buff *skb, struct flowi *fl, int reverse)
                case IPPROTO_TCP:
                case IPPROTO_SCTP:
                case IPPROTO_DCCP:
-                       if (!onlyproto && pskb_may_pull(skb, nh + offset + 4 - skb->data)) {
+                       if (!onlyproto && (nh + offset + 4 < skb->data ||
+                            pskb_may_pull(skb, nh + offset + 4 - skb->data))) {
                                __be16 *ports = (__be16 *)exthdr;
 
                                fl->fl_ip_sport = ports[!!reverse];
@@ -304,9 +306,24 @@ static void xfrm6_policy_fini(void)
        xfrm_policy_unregister_afinfo(&xfrm6_policy_afinfo);
 }
 
+static struct ctl_table xfrm6_policy_table[] = {
+       {
+               .ctl_name       = CTL_UNNUMBERED,
+               .procname       = "xfrm6_gc_thresh",
+               .data           = &xfrm6_dst_ops.gc_thresh,
+               .maxlen         = sizeof(int),
+               .mode           = 0644,
+               .proc_handler   = proc_dointvec,
+       },
+       { }
+};
+
+static struct ctl_table_header *sysctl_hdr;
+
 int __init xfrm6_init(void)
 {
        int ret;
+       unsigned int gc_thresh;
 
        ret = xfrm6_policy_init();
        if (ret)
@@ -315,6 +332,22 @@ int __init xfrm6_init(void)
        ret = xfrm6_state_init();
        if (ret)
                goto out_policy;
+       /*
+        * We need a good default value for the xfrm6 gc threshold.
+        * In ipv4 we set it to the route hash table size * 8, which
+        * is half the size of the maximaum route cache for ipv4.  It
+        * would be good to do the same thing for v6, except the table is
+        * constructed differently here.  Here each table for a net namespace
+        * can have FIB_TABLE_HASHSZ entries, so lets go with the same
+        * computation that we used for ipv4 here.  Also, lets keep the initial
+        * gc_thresh to a minimum of 1024, since, the ipv6 route cache defaults
+        * to that as a minimum as well
+        */
+       gc_thresh = FIB6_TABLE_HASHSZ * 8;
+       xfrm6_dst_ops.gc_thresh = (gc_thresh < 1024) ? 1024 : gc_thresh;
+
+       sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv6_ctl_path,
+                                               xfrm6_policy_table);
 out:
        return ret;
 out_policy:
@@ -324,6 +357,8 @@ out_policy:
 
 void xfrm6_fini(void)
 {
+       if (sysctl_hdr)
+               unregister_net_sysctl_table(sysctl_hdr);
        //xfrm6_input_fini();
        xfrm6_policy_fini();
        xfrm6_state_fini();