net: Fill in extack for mpls lwt encap

Fill in extack for errors in build_state for mpls lwt encap including
passing extack to nla_get_labels and adding error messages for failures
in it.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 257ec66009da2dd7010d063c0ad29dbb9a32564e..f3830951fb1c89441c61fe349f63d52ccd071811 100644 (file)
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -728,8 +728,8 @@ static int mpls_nh_build(struct net *net, struct mpls_route *rt,
                goto errout;
 
        if (newdst) {
-               err = nla_get_labels(newdst, max_labels,
-                                    &nh->nh_labels, nh->nh_label);
+               err = nla_get_labels(newdst, max_labels, &nh->nh_labels,
+                                    nh->nh_label, NULL);
                if (err)
                        goto errout;
        }
@@ -782,7 +782,8 @@ static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len,
 
                nla = nla_find(attrs, attrlen, RTA_NEWDST);
                if (nla &&
-                   nla_get_labels(nla, MAX_NEW_LABELS, &n_labels, NULL) != 0)
+                   nla_get_labels(nla, MAX_NEW_LABELS, &n_labels,
+                                  NULL, NULL) != 0)
                        return 0;
 
                *max_labels = max_t(u8, *max_labels, n_labels);
@@ -1541,8 +1542,8 @@ int nla_put_labels(struct sk_buff *skb, int attrtype,
 }
 EXPORT_SYMBOL_GPL(nla_put_labels);
 
-int nla_get_labels(const struct nlattr *nla,
-                  u8 max_labels, u8 *labels, u32 label[])
+int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
+                  u32 label[], struct netlink_ext_ack *extack)
 {
        unsigned len = nla_len(nla);
        struct mpls_shim_hdr *nla_label;
@@ -1553,13 +1554,18 @@ int nla_get_labels(const struct nlattr *nla,
        /* len needs to be an even multiple of 4 (the label size). Number
         * of labels is a u8 so check for overflow.
         */
-       if (len & 3 || len / 4 > 255)
+       if (len & 3 || len / 4 > 255) {
+               NL_SET_ERR_MSG_ATTR(extack, nla,
+                                   "Invalid length for labels attribute");
                return -EINVAL;
+       }
 
        /* Limit the number of new labels allowed */
        nla_labels = len/4;
-       if (nla_labels > max_labels)
+       if (nla_labels > max_labels) {
+               NL_SET_ERR_MSG(extack, "Too many labels");
                return -EINVAL;
+       }
 
        /* when label == NULL, caller wants number of labels */
        if (!label)
@@ -1574,8 +1580,29 @@ int nla_get_labels(const struct nlattr *nla,
                /* Ensure the bottom of stack flag is properly set
                 * and ttl and tc are both clear.
                 */
-               if ((dec.bos != bos) || dec.ttl || dec.tc)
+               if (dec.ttl) {
+                       NL_SET_ERR_MSG_ATTR(extack, nla,
+                                           "TTL in label must be 0");
+                       return -EINVAL;
+               }
+
+               if (dec.tc) {
+                       NL_SET_ERR_MSG_ATTR(extack, nla,
+                                           "Traffic class in label must be 0");
                        return -EINVAL;
+               }
+
+               if (dec.bos != bos) {
+                       NL_SET_BAD_ATTR(extack, nla);
+                       if (bos) {
+                               NL_SET_ERR_MSG(extack,
+                                              "BOS bit must be set in first label");
+                       } else {
+                               NL_SET_ERR_MSG(extack,
+                                              "BOS bit can only be set in first label");
+                       }
+                       return -EINVAL;
+               }
 
                switch (dec.label) {
                case MPLS_LABEL_IMPLNULL:
@@ -1583,6 +1610,8 @@ int nla_get_labels(const struct nlattr *nla,
                         * assign and distribute, but which never
                         * actually appears in the encapsulation.
                         */
+                       NL_SET_ERR_MSG_ATTR(extack, nla,
+                                           "Implicit NULL Label (3) can not be used in encapsulation");
                        return -EINVAL;
                }
 
@@ -1696,14 +1725,14 @@ static int rtm_to_route_config(struct sk_buff *skb,  struct nlmsghdr *nlh,
                case RTA_NEWDST:
                        if (nla_get_labels(nla, MAX_NEW_LABELS,
                                           &cfg->rc_output_labels,
-                                          cfg->rc_output_label))
+                                          cfg->rc_output_label, NULL))
                                goto errout;
                        break;
                case RTA_DST:
                {
                        u8 label_count;
                        if (nla_get_labels(nla, 1, &label_count,
-                                          &cfg->rc_label))
+                                          &cfg->rc_label, NULL))
                                goto errout;
 
                        /* Reserved labels may not be set */

diff --git a/net/mpls/internal.h b/net/mpls/internal.h
index 4db6a59713220dcefac8be970ab06b1ae25bcd5c..e59f299ceb3fd3fcb98239f61654881e58a082c8 100644 (file)
--- a/net/mpls/internal.h
+++ b/net/mpls/internal.h
@@ -203,7 +203,7 @@ static inline struct mpls_dev *mpls_dev_get(const struct net_device *dev)
 int nla_put_labels(struct sk_buff *skb, int attrtype,  u8 labels,
                   const u32 label[]);
 int nla_get_labels(const struct nlattr *nla, u8 max_labels, u8 *labels,
-                  u32 label[]);
+                  u32 label[], struct netlink_ext_ack *extack);
 int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
                u8 via[]);
 bool mpls_output_possible(const struct net_device *dev);

diff --git a/net/mpls/mpls_iptunnel.c b/net/mpls/mpls_iptunnel.c
index 15e1aa708e5007f81fbe1cd1bee49dd40525c0c2..6e558a419f60337a28426db411d88c7fed60213a 100644 (file)
--- a/net/mpls/mpls_iptunnel.c
+++ b/net/mpls/mpls_iptunnel.c
@@ -173,13 +173,14 @@ static int mpls_build_state(struct nlattr *nla,
        if (ret < 0)
                return ret;
 
-       if (!tb[MPLS_IPTUNNEL_DST])
+       if (!tb[MPLS_IPTUNNEL_DST]) {
+               NL_SET_ERR_MSG(extack, "MPLS_IPTUNNEL_DST attribute is missing");
                return -EINVAL;
-
+       }
 
        /* determine number of labels */
-       if (nla_get_labels(tb[MPLS_IPTUNNEL_DST],
-                          MAX_NEW_LABELS, &n_labels, NULL))
+       if (nla_get_labels(tb[MPLS_IPTUNNEL_DST], MAX_NEW_LABELS,
+                          &n_labels, NULL, extack))
                return -EINVAL;
 
        newts = lwtunnel_state_alloc(sizeof(*tun_encap_info) +
@@ -189,7 +190,8 @@ static int mpls_build_state(struct nlattr *nla,
 
        tun_encap_info = mpls_lwtunnel_encap(newts);
        ret = nla_get_labels(tb[MPLS_IPTUNNEL_DST], n_labels,
-                            &tun_encap_info->labels, tun_encap_info->label);
+                            &tun_encap_info->labels, tun_encap_info->label,
+                            extack);
        if (ret)
                goto errout;