[PATCH v2 net-next 09/11] net/mpls: Handle kernel side filtering of route dumps

[David Ahern]

From: David Ahern <dsah...@gmail.com>

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 <dsah...@gmail.com>
---
 net/mpls/af_mpls.c | 33 ++++++++++++++++++++++++++++-----
 1 file 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;
-- 
2.11.0