[ovs-dev] [QoS v2 08/17] netlink: Make nl_sock_transact() discard reply if 'replyp' is null.
Ben Pfaff
blp at nicira.com
Tue Jun 8 20:41:28 UTC 2010
Sometimes only the success or failure return value is interesting, not the
details of the reply, so this simplifies some callers.
---
lib/netlink.c | 19 ++++++++++++++-----
vswitchd/proc-net-compat.c | 5 ++---
2 files changed, 16 insertions(+), 8 deletions(-)
diff --git a/lib/netlink.c b/lib/netlink.c
index c773f1d..68e027e 100644
--- a/lib/netlink.c
+++ b/lib/netlink.c
@@ -341,9 +341,12 @@ try_again:
}
/* Sends 'request' to the kernel via 'sock' and waits for a response. If
- * successful, stores the reply into '*replyp' and returns 0. The caller is
- * responsible for destroying the reply with ofpbuf_delete(). On failure,
- * returns a positive errno value and stores a null pointer into '*replyp'.
+ * successful, returns 0. On failure, returns a positive errno value.
+ *
+ * If 'replyp' is nonnull, then on success '*replyp' is set to the kernel's
+ * reply, which the caller is responsible for freeing with ofpbuf_delete(), and
+ * on failure '*replyp' is set to NULL. If 'replyp' is null, then the kernel's
+ * reply, if any, is discarded.
*
* nlmsg_len in 'msg' will be finalized to match msg->size, and nlmsg_pid will
* be set to 'sock''s pid, before the message is sent. NLM_F_ACK will be set
@@ -386,7 +389,9 @@ nl_sock_transact(struct nl_sock *sock,
struct ofpbuf *reply;
int retval;
- *replyp = NULL;
+ if (replyp) {
+ *replyp = NULL;
+ }
/* Ensure that we get a reply even if this message doesn't ordinarily call
* for one. */
@@ -425,7 +430,11 @@ recv:
return retval != EAGAIN ? retval : EPROTO;
}
- *replyp = reply;
+ if (replyp) {
+ *replyp = reply;
+ } else {
+ ofpbuf_delete(reply);
+ }
return 0;
}
diff --git a/vswitchd/proc-net-compat.c b/vswitchd/proc-net-compat.c
index 72eb7be..106a7c3 100644
--- a/vswitchd/proc-net-compat.c
+++ b/vswitchd/proc-net-compat.c
@@ -72,7 +72,7 @@ proc_net_compat_init(void)
static int
set_proc_file(const char *dir, const char *file, const char *data)
{
- struct ofpbuf request, *reply;
+ struct ofpbuf request;
int retval;
ofpbuf_init(&request, 0);
@@ -84,9 +84,8 @@ set_proc_file(const char *dir, const char *file, const char *data)
nl_msg_put_string(&request, BRC_GENL_A_PROC_DATA, data);
}
- retval = nl_sock_transact(brc_sock, &request, &reply);
+ retval = nl_sock_transact(brc_sock, &request, NULL);
ofpbuf_uninit(&request);
- ofpbuf_delete(reply);
if (retval) {
VLOG_WARN_RL(&rl, "failed to %s /proc/%s/%s (%s)",
data ? "update" : "remove", dir, file, strerror(retval));
--
1.7.1
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