igmp: fix new sparse errors

[~andy/linux] / net / ipv4 / igmp.c

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index d8c232794bcb4bc995f850cabf42ac7bc8eac37a..cd71190d29625c11fe25aa603026cc98e0e2c34b 100644 (file)
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -363,7 +363,7 @@ static struct sk_buff *igmpv3_newpack(struct net_device *dev, int size)
 static int igmpv3_sendpack(struct sk_buff *skb)
 {
        struct igmphdr *pig = igmp_hdr(skb);
-       const int igmplen = skb->tail - skb->transport_header;
+       const int igmplen = skb_tail_pointer(skb) - skb_transport_header(skb);
 
        pig->csum = ip_compute_csum(igmp_hdr(skb), igmplen);
 
@@ -1217,6 +1217,57 @@ static void igmp_group_added(struct ip_mc_list *im)
  *     Multicast list managers
  */
 
+static u32 ip_mc_hash(const struct ip_mc_list *im)
+{
+       return hash_32((__force u32)im->multiaddr, MC_HASH_SZ_LOG);
+}
+
+static void ip_mc_hash_add(struct in_device *in_dev,
+                          struct ip_mc_list *im)
+{
+       struct ip_mc_list __rcu **mc_hash;
+       u32 hash;
+
+       mc_hash = rtnl_dereference(in_dev->mc_hash);
+       if (mc_hash) {
+               hash = ip_mc_hash(im);
+               im->next_hash = mc_hash[hash];
+               rcu_assign_pointer(mc_hash[hash], im);
+               return;
+       }
+
+       /* do not use a hash table for small number of items */
+       if (in_dev->mc_count < 4)
+               return;
+
+       mc_hash = kzalloc(sizeof(struct ip_mc_list *) << MC_HASH_SZ_LOG,
+                         GFP_KERNEL);
+       if (!mc_hash)
+               return;
+
+       for_each_pmc_rtnl(in_dev, im) {
+               hash = ip_mc_hash(im);
+               im->next_hash = mc_hash[hash];
+               RCU_INIT_POINTER(mc_hash[hash], im);
+       }
+
+       rcu_assign_pointer(in_dev->mc_hash, mc_hash);
+}
+
+static void ip_mc_hash_remove(struct in_device *in_dev,
+                             struct ip_mc_list *im)
+{
+       struct ip_mc_list __rcu **mc_hash = rtnl_dereference(in_dev->mc_hash);
+       struct ip_mc_list *aux;
+
+       if (!mc_hash)
+               return;
+       mc_hash += ip_mc_hash(im);
+       while ((aux = rtnl_dereference(*mc_hash)) != im)
+               mc_hash = &aux->next_hash;
+       *mc_hash = im->next_hash;
+}
+
 
 /*
  *     A socket has joined a multicast group on device dev.
@@ -1258,6 +1309,8 @@ void ip_mc_inc_group(struct in_device *in_dev, __be32 addr)
        in_dev->mc_count++;
        rcu_assign_pointer(in_dev->mc_list, im);
 
+       ip_mc_hash_add(in_dev, im);
+
 #ifdef CONFIG_IP_MULTICAST
        igmpv3_del_delrec(in_dev, im->multiaddr);
 #endif
@@ -1314,6 +1367,7 @@ void ip_mc_dec_group(struct in_device *in_dev, __be32 addr)
             ip = &i->next_rcu) {
                if (i->multiaddr == addr) {
                        if (--i->users == 0) {
+                               ip_mc_hash_remove(in_dev, i);
                                *ip = i->next_rcu;
                                in_dev->mc_count--;
                                igmp_group_dropped(i);
@@ -1381,13 +1435,9 @@ void ip_mc_init_dev(struct in_device *in_dev)
 {
        ASSERT_RTNL();
 
-       in_dev->mc_tomb = NULL;
 #ifdef CONFIG_IP_MULTICAST
-       in_dev->mr_gq_running = 0;
        setup_timer(&in_dev->mr_gq_timer, igmp_gq_timer_expire,
                        (unsigned long)in_dev);
-       in_dev->mr_ifc_count = 0;
-       in_dev->mc_count     = 0;
        setup_timer(&in_dev->mr_ifc_timer, igmp_ifc_timer_expire,
                        (unsigned long)in_dev);
        in_dev->mr_qrv = IGMP_Unsolicited_Report_Count;
@@ -2321,12 +2371,25 @@ void ip_mc_drop_socket(struct sock *sk)
 int ip_check_mc_rcu(struct in_device *in_dev, __be32 mc_addr, __be32 src_addr, u16 proto)
 {
        struct ip_mc_list *im;
+       struct ip_mc_list __rcu **mc_hash;
        struct ip_sf_list *psf;
        int rv = 0;
 
-       for_each_pmc_rcu(in_dev, im) {
-               if (im->multiaddr == mc_addr)
-                       break;
+       mc_hash = rcu_dereference(in_dev->mc_hash);
+       if (mc_hash) {
+               u32 hash = hash_32((__force u32)mc_addr, MC_HASH_SZ_LOG);
+
+               for (im = rcu_dereference(mc_hash[hash]);
+                    im != NULL;
+                    im = rcu_dereference(im->next_hash)) {
+                       if (im->multiaddr == mc_addr)
+                               break;
+               }
+       } else {
+               for_each_pmc_rcu(in_dev, im) {
+                       if (im->multiaddr == mc_addr)
+                               break;
+               }
        }
        if (im && proto == IPPROTO_IGMP) {
                rv = 1;