vxlan: change vxlan_[config_]validate() to use netlink_ext_ack for error reporting

The kernel log is not where users expect error messages for netlink
requests; as we have extended acks now, we can replace pr_debug() with
NL_SET_ERR_MSG_ATTR().

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>
Signed-off-by: Girish Moodalbail <girish.moodalbail@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 35e84a9..ae3a1da 100644 (file)
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -2729,12 +2729,14 @@ static int vxlan_validate(struct nlattr *tb[], struct nlattr *data[],
 {
        if (tb[IFLA_ADDRESS]) {
                if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN) {
-                       pr_debug("invalid link address (not ethernet)\n");
+                       NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_ADDRESS],
+                                           "Provided link layer address is not Ethernet");
                        return -EINVAL;
                }
 
                if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS]))) {
-                       pr_debug("invalid all zero ethernet address\n");
+                       NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_ADDRESS],
+                                           "Provided Ethernet address is not unicast");
                        return -EADDRNOTAVAIL;
                }
        }
@@ -2742,18 +2744,27 @@ static int vxlan_validate(struct nlattr *tb[], struct nlattr *data[],
        if (tb[IFLA_MTU]) {
                u32 mtu = nla_get_u32(tb[IFLA_MTU]);
 
-               if (mtu < ETH_MIN_MTU || mtu > ETH_MAX_MTU)
+               if (mtu < ETH_MIN_MTU || mtu > ETH_MAX_MTU) {
+                       NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_MTU],
+                                           "MTU must be between 68 and 65535");
                        return -EINVAL;
+               }
        }
 
-       if (!data)
+       if (!data) {
+               NL_SET_ERR_MSG(extack,
+                              "Required attributes not provided to perform the operation");
                return -EINVAL;
+       }
 
        if (data[IFLA_VXLAN_ID]) {
                u32 id = nla_get_u32(data[IFLA_VXLAN_ID]);
 
-               if (id >= VXLAN_N_VID)
+               if (id >= VXLAN_N_VID) {
+                       NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_VXLAN_ID],
+                                           "VXLAN ID must be lower than 16777216");
                        return -ERANGE;
+               }
        }
 
        if (data[IFLA_VXLAN_PORT_RANGE]) {
@@ -2761,8 +2772,8 @@ static int vxlan_validate(struct nlattr *tb[], struct nlattr *data[],
                        = nla_data(data[IFLA_VXLAN_PORT_RANGE]);
 
                if (ntohs(p->high) < ntohs(p->low)) {
-                       pr_debug("port range %u .. %u not valid\n",
-                                ntohs(p->low), ntohs(p->high));
+                       NL_SET_ERR_MSG_ATTR(extack, tb[IFLA_VXLAN_PORT_RANGE],
+                                           "Invalid source port range");
                        return -EINVAL;
                }
        }
@@ -2919,7 +2930,8 @@ static int vxlan_sock_add(struct vxlan_dev *vxlan)
 
 static int vxlan_config_validate(struct net *src_net, struct vxlan_config *conf,
                                 struct net_device **lower,
-                                struct vxlan_dev *old)
+                                struct vxlan_dev *old,
+                                struct netlink_ext_ack *extack)
 {
        struct vxlan_net *vn = net_generic(src_net, vxlan_net_id);
        struct vxlan_dev *tmp;
@@ -2933,6 +2945,8 @@ static int vxlan_config_validate(struct net *src_net, struct vxlan_config *conf,
                 */
                if ((conf->flags & ~VXLAN_F_ALLOWED_GPE) ||
                    !(conf->flags & VXLAN_F_COLLECT_METADATA)) {
+                       NL_SET_ERR_MSG(extack,
+                                      "VXLAN GPE does not support this combination of attributes");
                        return -EINVAL;
                }
        }
@@ -2947,15 +2961,23 @@ static int vxlan_config_validate(struct net *src_net, struct vxlan_config *conf,
                conf->saddr.sa.sa_family = conf->remote_ip.sa.sa_family;
        }
 
-       if (conf->saddr.sa.sa_family != conf->remote_ip.sa.sa_family)
+       if (conf->saddr.sa.sa_family != conf->remote_ip.sa.sa_family) {
+               NL_SET_ERR_MSG(extack,
+                              "Local and remote address must be from the same family");
                return -EINVAL;
+       }
 
-       if (vxlan_addr_multicast(&conf->saddr))
+       if (vxlan_addr_multicast(&conf->saddr)) {
+               NL_SET_ERR_MSG(extack, "Local address cannot be multicast");
                return -EINVAL;
+       }
 
        if (conf->saddr.sa.sa_family == AF_INET6) {
-               if (!IS_ENABLED(CONFIG_IPV6))
+               if (!IS_ENABLED(CONFIG_IPV6)) {
+                       NL_SET_ERR_MSG(extack,
+                                      "IPv6 support not enabled in the kernel");
                        return -EPFNOSUPPORT;
+               }
                use_ipv6 = true;
                conf->flags |= VXLAN_F_IPV6;
 
@@ -2967,46 +2989,68 @@ static int vxlan_config_validate(struct net *src_net, struct vxlan_config *conf,
 
                        if (local_type & IPV6_ADDR_LINKLOCAL) {
                                if (!(remote_type & IPV6_ADDR_LINKLOCAL) &&
-                                   (remote_type != IPV6_ADDR_ANY))
+                                   (remote_type != IPV6_ADDR_ANY)) {
+                                       NL_SET_ERR_MSG(extack,
+                                                      "Invalid combination of local and remote address scopes");
                                        return -EINVAL;
+                               }
 
                                conf->flags |= VXLAN_F_IPV6_LINKLOCAL;
                        } else {
                                if (remote_type ==
-                                   (IPV6_ADDR_UNICAST | IPV6_ADDR_LINKLOCAL))
+                                   (IPV6_ADDR_UNICAST | IPV6_ADDR_LINKLOCAL)) {
+                                       NL_SET_ERR_MSG(extack,
+                                                      "Invalid combination of local and remote address scopes");
                                        return -EINVAL;
+                               }
 
                                conf->flags &= ~VXLAN_F_IPV6_LINKLOCAL;
                        }
                }
        }
 
-       if (conf->label && !use_ipv6)
+       if (conf->label && !use_ipv6) {
+               NL_SET_ERR_MSG(extack,
+                              "Label attribute only applies to IPv6 VXLAN devices");
                return -EINVAL;
+       }
 
        if (conf->remote_ifindex) {
                struct net_device *lowerdev;
 
                lowerdev = __dev_get_by_index(src_net, conf->remote_ifindex);
-               if (!lowerdev)
+               if (!lowerdev) {
+                       NL_SET_ERR_MSG(extack,
+                                      "Invalid local interface, device not found");
                        return -ENODEV;
+               }
 
 #if IS_ENABLED(CONFIG_IPV6)
                if (use_ipv6) {
                        struct inet6_dev *idev = __in6_dev_get(lowerdev);
-                       if (idev && idev->cnf.disable_ipv6)
+                       if (idev && idev->cnf.disable_ipv6) {
+                               NL_SET_ERR_MSG(extack,
+                                              "IPv6 support disabled by administrator");
                                return -EPERM;
+                       }
                }
 #endif
 
                *lower = lowerdev;
        } else {
-               if (vxlan_addr_multicast(&conf->remote_ip))
+               if (vxlan_addr_multicast(&conf->remote_ip)) {
+                       NL_SET_ERR_MSG(extack,
+                                      "Local interface required for multicast remote destination");
+
                        return -EINVAL;
+               }
 
 #if IS_ENABLED(CONFIG_IPV6)
-               if (conf->flags & VXLAN_F_IPV6_LINKLOCAL)
+               if (conf->flags & VXLAN_F_IPV6_LINKLOCAL) {
+                       NL_SET_ERR_MSG(extack,
+                                      "Local interface required for link-local local/remote addresses");
                        return -EINVAL;
+               }
 #endif
 
                *lower = NULL;
@@ -3038,6 +3082,8 @@ static int vxlan_config_validate(struct net *src_net, struct vxlan_config *conf,
                    tmp->cfg.remote_ifindex != conf->remote_ifindex)
                        continue;
 
+               NL_SET_ERR_MSG(extack,
+                              "A VXLAN device with the specified VNI already exists");
                return -EEXIST;
        }
 
@@ -3097,14 +3143,14 @@ static void vxlan_config_apply(struct net_device *dev,
 }
 
 static int vxlan_dev_configure(struct net *src_net, struct net_device *dev,
-                              struct vxlan_config *conf,
-                              bool changelink)
+                              struct vxlan_config *conf, bool changelink,
+                              struct netlink_ext_ack *extack)
 {
        struct vxlan_dev *vxlan = netdev_priv(dev);
        struct net_device *lowerdev;
        int ret;
 
-       ret = vxlan_config_validate(src_net, conf, &lowerdev, vxlan);
+       ret = vxlan_config_validate(src_net, conf, &lowerdev, vxlan, extack);
        if (ret)
                return ret;
 
@@ -3114,13 +3160,14 @@ static int vxlan_dev_configure(struct net *src_net, struct net_device *dev,
 }
 
 static int __vxlan_dev_create(struct net *net, struct net_device *dev,
-                             struct vxlan_config *conf)
+                             struct vxlan_config *conf,
+                             struct netlink_ext_ack *extack)
 {
        struct vxlan_net *vn = net_generic(net, vxlan_net_id);
        struct vxlan_dev *vxlan = netdev_priv(dev);
        int err;
 
-       err = vxlan_dev_configure(net, dev, conf, false);
+       err = vxlan_dev_configure(net, dev, conf, false, extack);
        if (err)
                return err;
 
@@ -3366,7 +3413,7 @@ static int vxlan_newlink(struct net *src_net, struct net_device *dev,
        if (err)
                return err;
 
-       return __vxlan_dev_create(src_net, dev, &conf);
+       return __vxlan_dev_create(src_net, dev, &conf, extack);
 }
 
 static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
@@ -3386,7 +3433,7 @@ static int vxlan_changelink(struct net_device *dev, struct nlattr *tb[],
 
        memcpy(&old_dst, dst, sizeof(struct vxlan_rdst));
 
-       err = vxlan_dev_configure(vxlan->net, dev, &conf, true);
+       err = vxlan_dev_configure(vxlan->net, dev, &conf, true, extack);
        if (err)
                return err;
 
@@ -3592,7 +3639,7 @@ struct net_device *vxlan_dev_create(struct net *net, const char *name,
        if (IS_ERR(dev))
                return dev;
 
-       err = __vxlan_dev_create(net, dev, conf);
+       err = __vxlan_dev_create(net, dev, conf, NULL);
        if (err < 0) {
                free_netdev(dev);
                return ERR_PTR(err);