Re: [iproute PATCH v2 7/7] ip/tcp_metrics: Simplify process_msg a bit

Hi David,

On Wed, Jun 22, 2016 at 01:00:08PM +0000, David Laight wrote:

From: Jakub Sitnicki

quoted

Sent: 22 June 2016 12:34

...

quoted

quoted

-	a = attrs[TCP_METRICS_ATTR_ADDR_IPV4];
-	if (a) {
+	if ((a = attrs[TCP_METRICS_ATTR_ADDR_IPV4])) {

Copy the pointer inside the branch?

Same gain on indentation while keeping checkpatch happy.

Or as below (hacked from the mails):

	a = attrs[TCP_METRICS_ATTR_ADDR_IPV4];
	if (a) {
 		if (f.daddr.family && f.daddr.family != AF_INET)
 			return 0;
 		memcpy(&daddr.data, RTA_DATA(a), 4);
 		daddr.bytelen = 4;
 		family = AF_INET;
 		atype = TCP_METRICS_ATTR_ADDR_IPV4;
 		dlen = RTA_PAYLOAD(a);
	} else {
		a = attrs[TCP_METRICS_ATTR_ADDR_IPV6];
		if (!a)
			return 0;
		memcpy(&daddr.data, RTA_DATA(a), 16);
		daddr.bytelen = 16;
		family = AF_INET6;
		atype = TCP_METRICS_ATTR_ADDR_IPV6;
		dlen = RTA_PAYLOAD(a);
	}

Yes, this should work as well and require less code changes overall.
Though I think it's less readable:

| if (a) {
| 	do a;
| else {
| 	if (!b)
| 		return;
| 	do b;
| }

vs.

| if (a) {
| 	do a;
| } else if (b) {
| 	do b;
| } else {
| 	return;
| }

Don't you think?

Thanks, Phil