When writing a setting, sys_simple_nlquery() consumes the kernel reply via
nl_wait_for_ack(). This helper uses the socket's default callbacks instead
of state->cb, so sys_simple_nlerror() never runs and its (negative) return
value is discarded. A set request rejected by the kernel therefore prints
no error message and exits with EXIT_SUCCESS.
This can be seen easily by calling: "batctl meshif bat0 aggregation 1"
without CAP_NET_ADMIN.
Receive the reply through state->cb instead, like the read path already
does. The error handler then prints the kernel error, stores it in result
and the command exits with EXIT_FAILURE.
Fixes: 0b81e8fbaed5 ("batctl: Consume genl ACKs after setting reads")
Signed-off-by: Sven Eckelmann <[email protected]>
---
sys.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/sys.c b/sys.c
index 35a026e..a4d531f 100644
--- a/sys.c
+++ b/sys.c
@@ -110,10 +110,16 @@ int sys_simple_nlquery(struct state *state, enum
batadv_nl_commands nl_cmd,
if (callback) {
ret = nl_recvmsgs(state->sock, state->cb);
if (ret < 0)
- return ret;
+ return -EIO;
+
+ nl_wait_for_ack(state->sock);
+
+ return result;
}
- nl_wait_for_ack(state->sock);
+ ret = nl_recvmsgs(state->sock, state->cb);
+ if (ret < 0 && result >= 0)
+ result = -EIO;
return result;
}
--
2.47.3
