mptcp: pm: improve error messages

Some error messages were:

 - too generic: "missing input", "invalid request"

 - not precise enough: "limit greater than maximum" but what's the max?

 - missing: subflow not found, or connect error.

This can be easily improved by being more precise, or adding new error
messages.

Reviewed-by: Geliang Tang <geliang@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index 572d160edca33c0a941203d8ae0b0bde0f2ef3e2..1afa2bd8986231ae2eaab3a9c9044f841e2aea0e 100644 (file)
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1875,7 +1875,9 @@ static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
 
        *limit = nla_get_u32(attr);
        if (*limit > MPTCP_PM_ADDR_MAX) {
-               GENL_SET_ERR_MSG(info, "limit greater than maximum");
+               NL_SET_ERR_MSG_ATTR_FMT(info->extack, attr,
+                                       "limit greater than maximum (%u)",
+                                       MPTCP_PM_ADDR_MAX);
                return -EINVAL;
        }
        return 0;
@@ -2003,7 +2005,7 @@ int mptcp_pm_nl_set_flags(struct sk_buff *skb, struct genl_info *info)
        if (addr.addr.family == AF_UNSPEC) {
                lookup_by_id = 1;
                if (!addr.addr.id) {
-                       GENL_SET_ERR_MSG(info, "missing required inputs");
+                       GENL_SET_ERR_MSG(info, "missing address ID");
                        return -EOPNOTSUPP;
                }
        }

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index cdc83fabb7c2c45bc3d7c954a824c8f27bb85718..e350d6cc23bf2e23c5f255ede51570d8596b4585 100644 (file)
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -190,7 +190,7 @@ static struct mptcp_sock *mptcp_userspace_pm_get_sock(const struct genl_info *in
        }
 
        if (!mptcp_pm_is_userspace(msk)) {
-               GENL_SET_ERR_MSG(info, "invalid request; userspace PM not selected");
+               GENL_SET_ERR_MSG(info, "userspace PM not selected");
                sock_put((struct sock *)msk);
                return NULL;
        }
@@ -428,6 +428,9 @@ int mptcp_pm_nl_subflow_create_doit(struct sk_buff *skb, struct genl_info *info)
        err = __mptcp_subflow_connect(sk, &local, &addr_r);
        release_sock(sk);
 
+       if (err)
+               GENL_SET_ERR_MSG_FMT(info, "connect error: %d", err);
+
        spin_lock_bh(&msk->pm.lock);
        if (err)
                mptcp_userspace_pm_delete_local_addr(msk, &entry);
@@ -552,6 +555,7 @@ int mptcp_pm_nl_subflow_destroy_doit(struct sk_buff *skb, struct genl_info *info
        lock_sock(sk);
        ssk = mptcp_nl_find_ssk(msk, &addr_l.addr, &addr_r);
        if (!ssk) {
+               GENL_SET_ERR_MSG(info, "subflow not found");
                err = -ESRCH;
                goto release_sock;
        }
@@ -625,6 +629,10 @@ int mptcp_userspace_pm_set_flags(struct sk_buff *skb, struct genl_info *info)
        ret = mptcp_pm_nl_mp_prio_send_ack(msk, &loc.addr, &rem.addr, bkup);
        release_sock(sk);
 
+       /* mptcp_pm_nl_mp_prio_send_ack() only fails in one case */
+       if (ret < 0)
+               GENL_SET_ERR_MSG(info, "subflow not found");
+
 set_flags_err:
        sock_put(sk);
        return ret;