Re: [PATCH iproute2 1/3] iplink: Improve index parameter handling

On Mon, 18 Dec 2017 23:02:07 +0200
Serhey Popovich [off-list ref] wrote:

Stephen Hemminger wrote:

quoted

On Mon, 18 Dec 2017 20:54:06 +0200
Serhey Popovych [off-list ref] wrote:
  

quoted

diff --git a/ip/iplink.c b/ip/iplink.c
index 1e685cc..4f9c169 100644
--- a/ip/iplink.c
+++ b/ip/iplink.c

@@ -586,8 +586,10 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req,
 			*name = *argv;
 		} else if (strcmp(*argv, "index") == 0) {
 			NEXT_ARG();
+			if (*index)
+				duparg("index", *argv);
 			*index = atoi(*argv);
-			if (*index < 0)
+			if (*index <= 0)  

Why not use strtoul instead of atoi?  

Do not see reason for strtoul() instead atoi():

  1) main arg: indexes in kernel represented as "int", which is
     signed. <= 0 values are reserved for various special purposes
     (see net/core/fib_rules.c on how device matching implemented).

     Configuring network device manually with index <= 0 is not correct
     (however possible). Kernel itself never chooses ifindex <= 0.

     Having unsigned int > 0x7fffffff actually means index <= 0.

  2) this is not single place in iproute2 where it is used: not
     going to remove last user.

  3) make changes clear and transparent for review.

I would rather all of iproute2 correctly handles unsigned values.
Too much code is old K&R style C "the world is an int" and "who needs
to check for negative".

There already is get_unsigned() in iproute2 util functions.
Why not use that?