ipv6: some fixes for ipv6_dev_find()

This patch is to do 3 things for ipv6_dev_find():

  As David A. noticed,

  - rt6_lookup() is not really needed. Different from __ip_dev_find(),
    ipv6_dev_find() doesn't have a compatibility problem, so remove it.

  As Hideaki suggested,

  - "valid" (non-tentative) check for the address is also needed.
    ipv6_chk_addr() calls ipv6_chk_addr_and_flags(), which will
    traverse the address hash list, but it's heavy to be called
    inside ipv6_dev_find(). This patch is to reuse the code of
    ipv6_chk_addr_and_flags() for ipv6_dev_find().

  - dev parameter is passed into ipv6_dev_find(), as link-local
    addresses from user space has sin6_scope_id set and the dev
    lookup needs it.

Fixes: 81f6cb31222d ("ipv6: add ipv6_dev_find()")
Suggested-by: YOSHIFUJI Hideaki <hideaki.yoshifuji@miraclelinux.com>
Reported-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/addrconf.h b/include/net/addrconf.h
index ba3f6c1..18f783d 100644 (file)
--- a/include/net/addrconf.h
+++ b/include/net/addrconf.h
@@ -97,7 +97,8 @@ bool ipv6_chk_custom_prefix(const struct in6_addr *addr,
 
 int ipv6_chk_prefix(const struct in6_addr *addr, struct net_device *dev);
 
-struct net_device *ipv6_dev_find(struct net *net, const struct in6_addr *addr);
+struct net_device *ipv6_dev_find(struct net *net, const struct in6_addr *addr,
+                                struct net_device *dev);
 
 struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net,
                                     const struct in6_addr *addr,

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 8e761b8..01146b6 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1893,12 +1893,13 @@ EXPORT_SYMBOL(ipv6_chk_addr);
  *   2. does the address exist on the specific device
  *      (skip_dev_check = false)
  */
-int ipv6_chk_addr_and_flags(struct net *net, const struct in6_addr *addr,
-                           const struct net_device *dev, bool skip_dev_check,
-                           int strict, u32 banned_flags)
+static struct net_device *
+__ipv6_chk_addr_and_flags(struct net *net, const struct in6_addr *addr,
+                         const struct net_device *dev, bool skip_dev_check,
+                         int strict, u32 banned_flags)
 {
        unsigned int hash = inet6_addr_hash(net, addr);
-       const struct net_device *l3mdev;
+       struct net_device *l3mdev, *ndev;
        struct inet6_ifaddr *ifp;
        u32 ifp_flags;
 
@@ -1909,10 +1910,11 @@ int ipv6_chk_addr_and_flags(struct net *net, const struct in6_addr *addr,
                dev = NULL;
 
        hlist_for_each_entry_rcu(ifp, &inet6_addr_lst[hash], addr_lst) {
-               if (!net_eq(dev_net(ifp->idev->dev), net))
+               ndev = ifp->idev->dev;
+               if (!net_eq(dev_net(ndev), net))
                        continue;
 
-               if (l3mdev_master_dev_rcu(ifp->idev->dev) != l3mdev)
+               if (l3mdev_master_dev_rcu(ndev) != l3mdev)
                        continue;
 
                /* Decouple optimistic from tentative for evaluation here.
@@ -1923,15 +1925,23 @@ int ipv6_chk_addr_and_flags(struct net *net, const struct in6_addr *addr,
                            : ifp->flags;
                if (ipv6_addr_equal(&ifp->addr, addr) &&
                    !(ifp_flags&banned_flags) &&
-                   (!dev || ifp->idev->dev == dev ||
+                   (!dev || ndev == dev ||
                     !(ifp->scope&(IFA_LINK|IFA_HOST) || strict))) {
                        rcu_read_unlock();
-                       return 1;
+                       return ndev;
                }
        }
 
        rcu_read_unlock();
-       return 0;
+       return NULL;
+}
+
+int ipv6_chk_addr_and_flags(struct net *net, const struct in6_addr *addr,
+                           const struct net_device *dev, bool skip_dev_check,
+                           int strict, u32 banned_flags)
+{
+       return __ipv6_chk_addr_and_flags(net, addr, dev, skip_dev_check,
+                                        strict, banned_flags) ? 1 : 0;
 }
 EXPORT_SYMBOL(ipv6_chk_addr_and_flags);
 
@@ -1990,35 +2000,11 @@ EXPORT_SYMBOL(ipv6_chk_prefix);
  *
  * The caller should be protected by RCU, or RTNL.
  */
-struct net_device *ipv6_dev_find(struct net *net, const struct in6_addr *addr)
+struct net_device *ipv6_dev_find(struct net *net, const struct in6_addr *addr,
+                                struct net_device *dev)
 {
-       unsigned int hash = inet6_addr_hash(net, addr);
-       struct inet6_ifaddr *ifp, *result = NULL;
-       struct net_device *dev = NULL;
-
-       rcu_read_lock();
-       hlist_for_each_entry_rcu(ifp, &inet6_addr_lst[hash], addr_lst) {
-               if (net_eq(dev_net(ifp->idev->dev), net) &&
-                   ipv6_addr_equal(&ifp->addr, addr)) {
-                       result = ifp;
-                       break;
-               }
-       }
-
-       if (!result) {
-               struct rt6_info *rt;
-
-               rt = rt6_lookup(net, addr, NULL, 0, NULL, 0);
-               if (rt) {
-                       dev = rt->dst.dev;
-                       ip6_rt_put(rt);
-               }
-       } else {
-               dev = result->idev->dev;
-       }
-       rcu_read_unlock();
-
-       return dev;
+       return __ipv6_chk_addr_and_flags(net, addr, dev, !dev, 1,
+                                        IFA_F_TENTATIVE);
 }
 EXPORT_SYMBOL(ipv6_dev_find);
 

diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index 53f0de0..911d13c 100644 (file)
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -660,6 +660,7 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
        struct udp_tunnel_sock_cfg tuncfg = {NULL};
        struct nlattr *opts[TIPC_NLA_UDP_MAX + 1];
        u8 node_id[NODE_ID_LEN] = {0,};
+       struct net_device *dev;
        int rmcast = 0;
 
        ub = kzalloc(sizeof(*ub), GFP_ATOMIC);
@@ -714,8 +715,6 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
        rcu_assign_pointer(ub->bearer, b);
        tipc_udp_media_addr_set(&b->addr, &local);
        if (local.proto == htons(ETH_P_IP)) {
-               struct net_device *dev;
-
                dev = __ip_dev_find(net, local.ipv4.s_addr, false);
                if (!dev) {
                        err = -ENODEV;
@@ -738,9 +737,8 @@ static int tipc_udp_enable(struct net *net, struct tipc_bearer *b,
                b->mtu = b->media->mtu;
 #if IS_ENABLED(CONFIG_IPV6)
        } else if (local.proto == htons(ETH_P_IPV6)) {
-               struct net_device *dev;
-
-               dev = ipv6_dev_find(net, &local.ipv6);
+               dev = ub->ifindex ? __dev_get_by_index(net, ub->ifindex) : NULL;
+               dev = ipv6_dev_find(net, &local.ipv6, dev);
                if (!dev) {
                        err = -ENODEV;
                        goto err;