IPv6: add extack info for IPv6 address add/delete

Add extack info for IPv6 address add/delete, which would be useful for
users to understand the problem without having to read kernel code.

Suggested-by: Beniamino Galvani <bgalvani@redhat.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 3556595ce59a869413048f65c88d317d3bc9aee6..b32539bb0fb05c67b5849bb219be59fabe5bb51c 100644 (file)
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -156,7 +156,7 @@ void fib6_force_start_gc(struct net *net);
 
 struct fib6_info *addrconf_f6i_alloc(struct net *net, struct inet6_dev *idev,
                                     const struct in6_addr *addr, bool anycast,
-                                    gfp_t gfp_flags);
+                                    gfp_t gfp_flags, struct netlink_ext_ack *extack);
 
 struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
                               int flags);

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 94d1fdb0393f96cfadf13cee1a89d08e2bf6c2ce..5daf6a4986f8d189a677e396e6a0429c3a65c87f 100644 (file)
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1063,20 +1063,28 @@ ipv6_add_addr(struct inet6_dev *idev, struct ifa6_config *cfg,
        struct fib6_info *f6i = NULL;
        int err = 0;
 
-       if (addr_type == IPV6_ADDR_ANY ||
-           (addr_type & IPV6_ADDR_MULTICAST &&
-            !(cfg->ifa_flags & IFA_F_MCAUTOJOIN)) ||
-           (!(idev->dev->flags & IFF_LOOPBACK) &&
-            !netif_is_l3_master(idev->dev) &&
-            addr_type & IPV6_ADDR_LOOPBACK))
+       if (addr_type == IPV6_ADDR_ANY) {
+               NL_SET_ERR_MSG_MOD(extack, "Invalid address");
                return ERR_PTR(-EADDRNOTAVAIL);
+       } else if (addr_type & IPV6_ADDR_MULTICAST &&
+                  !(cfg->ifa_flags & IFA_F_MCAUTOJOIN)) {
+               NL_SET_ERR_MSG_MOD(extack, "Cannot assign multicast address without \"IFA_F_MCAUTOJOIN\" flag");
+               return ERR_PTR(-EADDRNOTAVAIL);
+       } else if (!(idev->dev->flags & IFF_LOOPBACK) &&
+                  !netif_is_l3_master(idev->dev) &&
+                  addr_type & IPV6_ADDR_LOOPBACK) {
+               NL_SET_ERR_MSG_MOD(extack, "Cannot assign loopback address on this device");
+               return ERR_PTR(-EADDRNOTAVAIL);
+       }
 
        if (idev->dead) {
-               err = -ENODEV;                  /*XXX*/
+               NL_SET_ERR_MSG_MOD(extack, "device is going away");
+               err = -ENODEV;
                goto out;
        }
 
        if (idev->cnf.disable_ipv6) {
+               NL_SET_ERR_MSG_MOD(extack, "IPv6 is disabled on this device");
                err = -EACCES;
                goto out;
        }
@@ -1103,7 +1111,7 @@ ipv6_add_addr(struct inet6_dev *idev, struct ifa6_config *cfg,
                goto out;
        }
 
-       f6i = addrconf_f6i_alloc(net, idev, cfg->pfx, false, gfp_flags);
+       f6i = addrconf_f6i_alloc(net, idev, cfg->pfx, false, gfp_flags, extack);
        if (IS_ERR(f6i)) {
                err = PTR_ERR(f6i);
                f6i = NULL;
@@ -2927,30 +2935,40 @@ static int inet6_addr_add(struct net *net, int ifindex,
 
        ASSERT_RTNL();
 
-       if (cfg->plen > 128)
+       if (cfg->plen > 128) {
+               NL_SET_ERR_MSG_MOD(extack, "Invalid prefix length");
                return -EINVAL;
+       }
 
        /* check the lifetime */
-       if (!cfg->valid_lft || cfg->preferred_lft > cfg->valid_lft)
+       if (!cfg->valid_lft || cfg->preferred_lft > cfg->valid_lft) {
+               NL_SET_ERR_MSG_MOD(extack, "address lifetime invalid");
                return -EINVAL;
+       }
 
-       if (cfg->ifa_flags & IFA_F_MANAGETEMPADDR && cfg->plen != 64)
+       if (cfg->ifa_flags & IFA_F_MANAGETEMPADDR && cfg->plen != 64) {
+               NL_SET_ERR_MSG_MOD(extack, "address with \"mngtmpaddr\" flag must have a prefix length of 64");
                return -EINVAL;
+       }
 
        dev = __dev_get_by_index(net, ifindex);
        if (!dev)
                return -ENODEV;
 
        idev = addrconf_add_dev(dev);
-       if (IS_ERR(idev))
+       if (IS_ERR(idev)) {
+               NL_SET_ERR_MSG_MOD(extack, "IPv6 is disabled on this device");
                return PTR_ERR(idev);
+       }
 
        if (cfg->ifa_flags & IFA_F_MCAUTOJOIN) {
                int ret = ipv6_mc_config(net->ipv6.mc_autojoin_sk,
                                         true, cfg->pfx, ifindex);
 
-               if (ret < 0)
+               if (ret < 0) {
+                       NL_SET_ERR_MSG_MOD(extack, "Multicast auto join failed");
                        return ret;
+               }
        }
 
        cfg->scope = ipv6_addr_scope(cfg->pfx);
@@ -3007,22 +3025,29 @@ static int inet6_addr_add(struct net *net, int ifindex,
 }
 
 static int inet6_addr_del(struct net *net, int ifindex, u32 ifa_flags,
-                         const struct in6_addr *pfx, unsigned int plen)
+                         const struct in6_addr *pfx, unsigned int plen,
+                         struct netlink_ext_ack *extack)
 {
        struct inet6_ifaddr *ifp;
        struct inet6_dev *idev;
        struct net_device *dev;
 
-       if (plen > 128)
+       if (plen > 128) {
+               NL_SET_ERR_MSG_MOD(extack, "Invalid prefix length");
                return -EINVAL;
+       }
 
        dev = __dev_get_by_index(net, ifindex);
-       if (!dev)
+       if (!dev) {
+               NL_SET_ERR_MSG_MOD(extack, "Unable to find the interface");
                return -ENODEV;
+       }
 
        idev = __in6_dev_get(dev);
-       if (!idev)
+       if (!idev) {
+               NL_SET_ERR_MSG_MOD(extack, "IPv6 is disabled on this device");
                return -ENXIO;
+       }
 
        read_lock_bh(&idev->lock);
        list_for_each_entry(ifp, &idev->addr_list, if_list) {
@@ -3045,6 +3070,8 @@ static int inet6_addr_del(struct net *net, int ifindex, u32 ifa_flags,
                }
        }
        read_unlock_bh(&idev->lock);
+
+       NL_SET_ERR_MSG_MOD(extack, "address not found");
        return -EADDRNOTAVAIL;
 }
 
@@ -3087,7 +3114,7 @@ int addrconf_del_ifaddr(struct net *net, void __user *arg)
 
        rtnl_lock();
        err = inet6_addr_del(net, ireq.ifr6_ifindex, 0, &ireq.ifr6_addr,
-                            ireq.ifr6_prefixlen);
+                            ireq.ifr6_prefixlen, NULL);
        rtnl_unlock();
        return err;
 }
@@ -3490,7 +3517,7 @@ static int fixup_permanent_addr(struct net *net,
                struct fib6_info *f6i, *prev;
 
                f6i = addrconf_f6i_alloc(net, idev, &ifp->addr, false,
-                                        GFP_ATOMIC);
+                                        GFP_ATOMIC, NULL);
                if (IS_ERR(f6i))
                        return PTR_ERR(f6i);
 
@@ -4700,7 +4727,7 @@ inet6_rtm_deladdr(struct sk_buff *skb, struct nlmsghdr *nlh,
        ifa_flags &= IFA_F_MANAGETEMPADDR;
 
        return inet6_addr_del(net, ifm->ifa_index, ifa_flags, pfx,
-                             ifm->ifa_prefixlen);
+                             ifm->ifa_prefixlen, extack);
 }
 
 static int modify_prefix_route(struct inet6_ifaddr *ifp,
@@ -4905,8 +4932,10 @@ inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh,
        }
 
        dev =  __dev_get_by_index(net, ifm->ifa_index);
-       if (!dev)
+       if (!dev) {
+               NL_SET_ERR_MSG_MOD(extack, "Unable to find the interface");
                return -ENODEV;
+       }
 
        if (tb[IFA_FLAGS])
                cfg.ifa_flags = nla_get_u32(tb[IFA_FLAGS]);
@@ -4941,10 +4970,12 @@ inet6_rtm_newaddr(struct sk_buff *skb, struct nlmsghdr *nlh,
        }
 
        if (nlh->nlmsg_flags & NLM_F_EXCL ||
-           !(nlh->nlmsg_flags & NLM_F_REPLACE))
+           !(nlh->nlmsg_flags & NLM_F_REPLACE)) {
+               NL_SET_ERR_MSG_MOD(extack, "address already assigned");
                err = -EEXIST;
-       else
+       } else {
                err = inet6_addr_modify(net, ifa, &cfg);
+       }
 
        in6_ifa_put(ifa);
 

diff --git a/net/ipv6/anycast.c b/net/ipv6/anycast.c
index dacdea7fcb628d34b684da234d130d0e95f3e90a..bb17f484ee2cde62632f95fc3b3370618b116049 100644 (file)
--- a/net/ipv6/anycast.c
+++ b/net/ipv6/anycast.c
@@ -305,7 +305,7 @@ int __ipv6_dev_ac_inc(struct inet6_dev *idev, const struct in6_addr *addr)
        }
 
        net = dev_net(idev->dev);
-       f6i = addrconf_f6i_alloc(net, idev, addr, true, GFP_ATOMIC);
+       f6i = addrconf_f6i_alloc(net, idev, addr, true, GFP_ATOMIC, NULL);
        if (IS_ERR(f6i)) {
                err = PTR_ERR(f6i);
                goto out;

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 64e873f5895f1907b813d675a9ea46f5db3f429c..c90700aed3a191773277e97bb5a33552774aa30f 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -4543,7 +4543,8 @@ static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff
 struct fib6_info *addrconf_f6i_alloc(struct net *net,
                                     struct inet6_dev *idev,
                                     const struct in6_addr *addr,
-                                    bool anycast, gfp_t gfp_flags)
+                                    bool anycast, gfp_t gfp_flags,
+                                    struct netlink_ext_ack *extack)
 {
        struct fib6_config cfg = {
                .fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL,
@@ -4565,7 +4566,7 @@ struct fib6_info *addrconf_f6i_alloc(struct net *net,
                cfg.fc_flags |= RTF_LOCAL;
        }
 
-       f6i = ip6_route_info_create(&cfg, gfp_flags, NULL);
+       f6i = ip6_route_info_create(&cfg, gfp_flags, extack);
        if (!IS_ERR(f6i)) {
                f6i->dst_nocount = true;