Re: [PATCH iproute2-next 1/8] iplink: Return from function instead of calling exit()

On Tue, Feb 20, 2018 at 12:49 PM, David Ahern [off-list ref] wrote:

On 2/20/18 1:44 PM, Roopa Prabhu wrote:

quoted

On Tue, Feb 20, 2018 at 12:33 PM, Stephen Hemminger
[off-list ref] wrote:

quoted

On Tue, 20 Feb 2018 13:27:21 -0700
David Ahern [off-list ref] wrote:

quoted

On 2/20/18 1:17 PM, Serhey Popovych wrote:

quoted

Stephen Hemminger wrote:

quoted

On Tue, 20 Feb 2018 21:39:51 +0200
Serhey Popovych [off-list ref] wrote:

quoted

Signed-off-by: Serhey Popovych <redacted>
---
 ip/iplink.c |   12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/ip/iplink.c b/ip/iplink.c
index 74c377c..a2c8108 100644
--- a/ip/iplink.c
+++ b/ip/iplink.c

@@ -653,7 +653,7 @@ int iplink_parse(int argc, char **argv, struct iplink_req *req,
                  NEXT_ARG();
                  if (xdp_parse(&argc, &argv, req, dev_index,
                                generic, drv, offload))
-                         exit(-1);
+                         return -1;
          } else if (strcmp(*argv, "netns") == 0) {
                  NEXT_ARG();
                  if (netns != -1)

@@ -972,12 +972,12 @@ static int iplink_modify(int cmd, unsigned int flags, int argc, char **argv)
          if (!dev) {
                  fprintf(stderr,
                          "Not enough information: \"dev\" argument is required.\n");
-                 exit(-1);
+                 return -1;
          }
          if (cmd == RTM_NEWLINK && index) {
                  fprintf(stderr,
                          "index can be used only when creating devices.\n");
-                 exit(-1);
+                 return -1;
          }

          req.i.ifi_index = ll_name_to_index(dev);

@@ -1392,7 +1392,7 @@ static int do_set(int argc, char **argv)
  if (!dev) {
          fprintf(stderr,
                  "Not enough of information: \"dev\" argument is required.\n");
-         exit(-1);
+         return -1;
  }

  if (newaddr || newbrd) {

@@ -1553,7 +1553,7 @@ static int iplink_afstats(int argc, char **argv)
                  fprintf(stderr,
                          "Command \"%s\" is unknown, try \"ip link help\".\n",
                          *argv);
-                 exit(-1);
+                 return -1;
          }

          argv++; argc--;

@@ -1648,5 +1648,5 @@ int do_iplink(int argc, char **argv)

  fprintf(stderr, "Command \"%s\" is unknown, try \"ip link help\".\n",
          *argv);
- exit(-1);
+ return -1;
 }

Not sure I like this. If given bad input in batch it is better to stop and exit
rather than continuing with more bad data.

When preparing this change I think in opposite direction: we want to
continue batch mode if single line is broken.

batch mode needs to stop on the line that fails. That said, batch still
fails with the /exit/return/ change

$ cat /tmp/ip.batch
li sh
li foo
li add veth1 type veth peer name veth2

Current command
$ ip -batch /tmp/ip.batch
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode
DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00

<link list snipped>
Command "foo" is unknown, try "ip link help".
$ echo $?
255

$ ip/ip -batch /tmp/ip.batch
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode
DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
<link list snipped>
Command "foo" is unknown, try "ip link help".
Command failed /tmp/ip.batch:2
dsa@kenny:~/iproute2/iproute2-next.git$ echo $?
1

I like that better because it tells me the line that fails.

Normally ip batch will exit on errors.
The question is what about -force?

on -force, it needs to continue.

It does.

$ ip/ip -batch /tmp/ip.batch -force
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN mode
DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
<snipped>
Command "foo" is unknown, try "ip link help".
Command failed /tmp/ip.batch:2
RTNETLINK answers: Operation not permitted
Command failed /tmp/ip.batch:3

Which is an improvement over today where it just exits - ignoring the force.

cool :).

some other iproute2 commands have also received patches to continue on
-force over the last few years.