mptcp: set error messages for set_flags

In addition to returning the error value, this patch also sets an error
messages with GENL_SET_ERR_MSG or NL_SET_ERR_MSG_ATTR both for pm_netlink.c
and pm_userspace.c. It will help the userspace to identify the issue.

Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20240305-upstream-net-next-20240304-mptcp-misc-cleanup-v1-3-c436ba5e569b@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index c799fe84dfd36bb1c33a0d87445c1a95dc94bc93..354083b8386f0ccab1dffb2b5714729673002793 100644 (file)
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -1908,8 +1908,10 @@ 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)
+               if (!addr.addr.id) {
+                       GENL_SET_ERR_MSG(info, "missing required inputs");
                        return -EOPNOTSUPP;
+               }
        }
 
        if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
@@ -1919,11 +1921,13 @@ int mptcp_pm_nl_set_flags(struct sk_buff *skb, struct genl_info *info)
        entry = __lookup_addr(pernet, &addr.addr, lookup_by_id);
        if (!entry) {
                spin_unlock_bh(&pernet->lock);
+               GENL_SET_ERR_MSG(info, "address not found");
                return -EINVAL;
        }
        if ((addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) &&
            (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
                spin_unlock_bh(&pernet->lock);
+               GENL_SET_ERR_MSG(info, "invalid addr flags");
                return -EINVAL;
        }
 

diff --git a/net/mptcp/pm_userspace.c b/net/mptcp/pm_userspace.c
index 7ef3b69852f002e1b04228c9784d86f04ee24ec8..9f5d422d5ef6c129d5483cedd5bfcc0793f65f24 100644 (file)
--- a/net/mptcp/pm_userspace.c
+++ b/net/mptcp/pm_userspace.c
@@ -563,13 +563,17 @@ int mptcp_userspace_pm_set_flags(struct sk_buff *skb, struct genl_info *info)
        token_val = nla_get_u32(token);
 
        msk = mptcp_token_get_sock(net, token_val);
-       if (!msk)
+       if (!msk) {
+               NL_SET_ERR_MSG_ATTR(info->extack, token, "invalid token");
                return ret;
+       }
 
        sk = (struct sock *)msk;
 
-       if (!mptcp_pm_is_userspace(msk))
+       if (!mptcp_pm_is_userspace(msk)) {
+               GENL_SET_ERR_MSG(info, "userspace PM not selected");
                goto set_flags_err;
+       }
 
        ret = mptcp_pm_parse_entry(attr, info, false, &loc);
        if (ret < 0)
@@ -583,6 +587,7 @@ int mptcp_userspace_pm_set_flags(struct sk_buff *skb, struct genl_info *info)
 
        if (loc.addr.family == AF_UNSPEC ||
            rem.addr.family == AF_UNSPEC) {
+               GENL_SET_ERR_MSG(info, "invalid address families");
                ret = -EINVAL;
                goto set_flags_err;
        }