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>

1 files changed, 56 insertions, 33 deletions

diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index beb76b7989a7..04399cb71e14 100644
--- 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)