net: ipv6: mld: refactor query processing into v1/v2 functions

Make igmp6_event_query() a bit easier to read by refactoring code
parts into mld_process_v1() and mld_process_v2().

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index beb76b7989a7c75f1b151d68f05b5be3b4ed1853..04399cb71e14d88db6ba03ec0d0cb7a4ac296dbf 100644 (file)
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1218,6 +1218,55 @@ static void mld_update_qri(struct inet6_dev *idev,
        idev->mc_qri = msecs_to_jiffies(mldv2_mrc(mlh2));
 }
 
+static int mld_process_v1(struct inet6_dev *idev, struct mld_msg *mld,
+                         unsigned long *max_delay)
+{
+       unsigned long mldv1_md;
+
+       /* Ignore v1 queries */
+       if (mld_in_v2_mode_only(idev))
+               return -EINVAL;
+
+       /* MLDv1 router present */
+       mldv1_md = ntohs(mld->mld_maxdelay);
+       *max_delay = max(msecs_to_jiffies(mldv1_md), 1UL);
+
+       mld_set_v1_mode(idev);
+
+       /* cancel MLDv2 report timer */
+       idev->mc_gq_running = 0;
+       if (del_timer(&idev->mc_gq_timer))
+               __in6_dev_put(idev);
+
+       /* cancel the interface change timer */
+       idev->mc_ifc_count = 0;
+       if (del_timer(&idev->mc_ifc_timer))
+               __in6_dev_put(idev);
+
+       /* clear deleted report items */
+       mld_clear_delrec(idev);
+
+       return 0;
+}
+
+static int mld_process_v2(struct inet6_dev *idev, struct mld2_query *mld,
+                         unsigned long *max_delay)
+{
+       /* hosts need to stay in MLDv1 mode, discard MLDv2 queries */
+       if (mld_in_v1_mode(idev))
+               return -EINVAL;
+
+       *max_delay = max(msecs_to_jiffies(mldv2_mrc(mld)), 1UL);
+
+       mld_update_qrv(idev, mld);
+       mld_update_qi(idev, mld);
+       mld_update_qri(idev, mld);
+
+       idev->mc_maxdelay = *max_delay;
+
+       return 0;
+}
+
 /* called with rcu_read_lock() */
 int igmp6_event_query(struct sk_buff *skb)
 {
@@ -1229,7 +1278,7 @@ int igmp6_event_query(struct sk_buff *skb)
        struct mld_msg *mld;
        int group_type;
        int mark = 0;
-       int len;
+       int len, err;
 
        if (!pskb_may_pull(skb, sizeof(struct in6_addr)))
                return -EINVAL;
@@ -1255,47 +1304,21 @@ int igmp6_event_query(struct sk_buff *skb)
                return -EINVAL;
 
        if (len == MLD_V1_QUERY_LEN) {
-               unsigned long mldv1_md;
-
-               /* Ignore v1 queries */
-               if (mld_in_v2_mode_only(idev))
-                       return 0;
-
-               /* MLDv1 router present */
-               mldv1_md = ntohs(mld->mld_maxdelay);
-               max_delay = max(msecs_to_jiffies(mldv1_md), 1UL);
-
-               mld_set_v1_mode(idev);
-
-               /* cancel MLDv2 report timer */
-               idev->mc_gq_running = 0;
-               if (del_timer(&idev->mc_gq_timer))
-                       __in6_dev_put(idev);
-
-               /* cancel the interface change timer */
-               idev->mc_ifc_count = 0;
-               if (del_timer(&idev->mc_ifc_timer))
-                       __in6_dev_put(idev);
-               /* clear deleted report items */
-               mld_clear_delrec(idev);
+               err = mld_process_v1(idev, mld, &max_delay);
+               if (err < 0)
+                       return err;
        } else if (len >= MLD_V2_QUERY_LEN_MIN) {
                int srcs_offset = sizeof(struct mld2_query) -
                                  sizeof(struct icmp6hdr);
 
-               /* hosts need to stay in MLDv1 mode, discard MLDv2 queries */
-               if (mld_in_v1_mode(idev))
-                       return 0;
                if (!pskb_may_pull(skb, srcs_offset))
                        return -EINVAL;
 
                mlh2 = (struct mld2_query *)skb_transport_header(skb);
 
-               max_delay = max(msecs_to_jiffies(mldv2_mrc(mlh2)), 1UL);
-               idev->mc_maxdelay = max_delay;
-
-               mld_update_qrv(idev, mlh2);
-               mld_update_qi(idev, mlh2);
-               mld_update_qri(idev, mlh2);
+               err = mld_process_v2(idev, mlh2, &max_delay);
+               if (err < 0)
+                       return err;
 
                if (group_type == IPV6_ADDR_ANY) { /* general query */
                        if (mlh2->mld2q_nsrcs)