net/mpls: Handle kernel side filtering of route dumps

Update the dump request parsing in MPLS for the non-INET case to
enable kernel side filtering. If INET is disabled the only filters
that make sense for MPLS are protocol and nexthop device.

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

1 files changed, 28 insertions, 5 deletions

diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 24381696932a..7d55d4c04088 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -2044,7 +2044,9 @@ static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
                                    struct netlink_callback *cb)
 {
         struct netlink_ext_ack *extack = cb->extack;
+        struct nlattr *tb[RTA_MAX + 1];
         struct rtmsg *rtm;
+        int err, i;
 
         if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
                 NL_SET_ERR_MSG_MOD(extack, "Invalid header for FIB dump request");
@@ -2053,15 +2055,36 @@ static int mpls_valid_fib_dump_req(struct net *net, const struct nlmsghdr *nlh,
 
         rtm = nlmsg_data(nlh);
         if (rtm->rtm_dst_len || rtm->rtm_src_len  || rtm->rtm_tos   ||
-            rtm->rtm_table   || rtm->rtm_protocol || rtm->rtm_scope ||
-            rtm->rtm_type    || rtm->rtm_flags) {
+            rtm->rtm_table   || rtm->rtm_scope    || rtm->rtm_type  ||
+            rtm->rtm_flags) {
                 NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for FIB dump request");
                 return -EINVAL;
         }
 
-        if (nlmsg_attrlen(nlh, sizeof(*rtm))) {
-                NL_SET_ERR_MSG_MOD(extack, "Invalid data after header in FIB dump request");
-                return -EINVAL;
+        if (rtm->rtm_protocol) {
+                filter->protocol = rtm->rtm_protocol;
+                filter->filter_set = 1;
+                cb->answer_flags = NLM_F_DUMP_FILTERED;
+        }
+
+        err = nlmsg_parse_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
+                                 rtm_mpls_policy, extack);
+        if (err < 0)
+                return err;
+
+        for (i = 0; i <= RTA_MAX; ++i) {
+                int ifindex;
+
+                if (i == RTA_OIF) {
+                        ifindex = nla_get_u32(tb[i]);
+                        filter->dev = __dev_get_by_index(net, ifindex);
+                        if (!filter->dev)
+                                return -ENODEV;
+                        filter->filter_set = 1;
+                } else if (tb[i]) {
+                        NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in dump request");
+                        return -EINVAL;
+                }
         }
 
         return 0;