[PATCH] iproute2: ip: add wilcard support for device matching

[PATCH] iproute2: ip: add wilcard support for device matching

[Octavian Purdila]

Allow the users to specify a wildcard when selecting a device:

$ ip set link dev dummy* up

We do this by expanding the original command line in multiple lines
which we then feed via a pipe to a forked ip processed run in batch
mode.

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
---
 ip/ip.c |   70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 70 insertions(+), 0 deletions(-)

diff --git a/ip/ip.c b/ip/ip.c
index b127d57..2e26488 100644
--- a/ip/ip.c
+++ b/ip/ip.c
@@ -18,6 +18,8 @@
 #include <netinet/in.h>
 #include <string.h>
 #include <errno.h>
+#include <sys/types.h>
+#include <sys/wait.h>
 
 #include "SNAPSHOT.h"
 #include "utils.h"
@@ -139,10 +141,72 @@ static int batch(const char *name)
 	return ret;
 }
 
+int main(int argc, char **argv);
+
+int expand_dev_pattern(int argc, char **argv, int pos)
+{
+	FILE *proc;
+	size_t n, dev_no;
+	char scanf_pattern[64], *line = NULL, *dev_base = argv[pos];
+	int p[2], i;
+	pid_t pid;
+
+	*strchr(dev_base, '*') = 0;
+	snprintf(scanf_pattern, sizeof(scanf_pattern), " %s%%d:", dev_base);
+
+	if (pipe(p) < 0) {
+		fprintf(stderr, "pipe() failed: %s\n", strerror(errno));
+		return -1;
+	}
+
+	pid = fork();
+	switch (pid) {
+	case -1:
+		fprintf(stderr, "fork failed: %s\n", strerror(errno));
+		return -1;
+	case 0:
+	{
+		char *nargv[] = { argv[0], "-b", "-" };
+		int ret;
+
+		dup2(p[0], 0); close(p[0]); close(p[1]);
+		ret = main(3, nargv);
+		exit(ret);
+	}
+	default:
+		dup2(p[1], 1); close(p[0]); close(p[1]);
+	}
+
+	proc = fopen("/proc/net/dev", "r");
+	if (!proc) {
+		fprintf(stderr, "can't open /proc/net/dev\n");
+		return -1;
+	}
+
+	while (getline(&line, &n, proc) > 0) {
+		if (sscanf(line, scanf_pattern, &dev_no) == 1) {
+			for (i = 1; i < argc; i++)
+				if (i != pos)
+					printf("%s ", argv[i]);
+				else
+					printf("%s%d ", dev_base, dev_no);
+			printf("\n");
+		}
+	}
+	free(line);
+
+	fflush(stdout); close(1);
+
+	waitpid(pid, NULL, 0);
+
+	return 0;
+}
 
 int main(int argc, char **argv)
 {
 	char *basename;
+	int i = 0;
+
 
 	basename = strrchr(argv[0], '/');
 	if (basename == NULL)
@@ -150,6 +214,12 @@ int main(int argc, char **argv)
 	else
 		basename++;
 
+	for (i = 1; i < argc - 1; i++) {
+		if (matches(argv[i], "dev") == 0 && strchr(argv[i+1], '*')) {
+			return expand_dev_pattern(argc, argv, i+1);
+		}
+	}
+
 	while (argc > 1) {
 		char *opt = argv[1];
 		if (strcmp(opt,"--") == 0) {
-- 
1.7.1

Re: [PATCH] iproute2: ip: add wilcard support for device matching

[Stephen Hemminger]

On Fri, 10 Dec 2010 16:58:12 +0200
Octavian Purdila <opurdila@ixiacom.com> wrote:

> Allow the users to specify a wildcard when selecting a device:
> 
> $ ip set link dev dummy* up
> 
> We do this by expanding the original command line in multiple lines
> which we then feed via a pipe to a forked ip processed run in batch
> mode.
> 


Seems like feature creep. Can't you do this with bash completion
script instead.

Re: [PATCH] iproute2: ip: add wilcard support for device matching

[Eric Dumazet]

Le vendredi 10 décembre 2010 à 08:18 -0800, Stephen Hemminger a écrit :
> On Fri, 10 Dec 2010 16:58:12 +0200
> Octavian Purdila <opurdila@ixiacom.com> wrote:
> 
> > Allow the users to specify a wildcard when selecting a device:
> > 
> > $ ip set link dev dummy* up
> > 
> > We do this by expanding the original command line in multiple lines
> > which we then feed via a pipe to a forked ip processed run in batch
> > mode.
> > 
> 
> 
> Seems like feature creep. Can't you do this with bash completion
> script instead.
> -

furthermore, "*" is allowed in a device name

ip link add link bond0 "vlan*" txqueuelen 100 type vlan id 999

$ ifconfig "vlan*"
vlan*     Link encap:Ethernet  HWaddr 00:1E:0B:EC:D3:D2  
          BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

Re: [PATCH] iproute2: ip: add wilcard support for device matching

[Octavian Purdila]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Friday 10 December 2010, 18:32:20

> Le vendredi 10 décembre 2010 à 08:18 -0800, Stephen Hemminger a écrit :
> > On Fri, 10 Dec 2010 16:58:12 +0200
> > 
> > Octavian Purdila <opurdila@ixiacom.com> wrote:
> > > Allow the users to specify a wildcard when selecting a device:
> > > 
> > > $ ip set link dev dummy* up
> > > 
> > > We do this by expanding the original command line in multiple lines
> > > which we then feed via a pipe to a forked ip processed run in batch
> > > mode.
> > 
> > Seems like feature creep. Can't you do this with bash completion
> > script instead.

This feature would make my life easier so to me its just a nice feature  :) 
Sure I can do it as a bash completion script but:

- bash does not run everywhere

- having it in iproute would make it available to everyone

- its userspace so the price to pay for a few more lines of code for usability 
seems reasonable

- I don't know how scalable you can make the bash completion script

> furthermore, "*" is allowed in a device name
> 
> ip link add link bond0 "vlan*" txqueuelen 100 type vlan id 999
> 

Would allowing escaping it fix the issue? Like:

ip link add link bond0 "vlan\*" txqueuelen 100 type vlan id 999

Re: [PATCH] iproute2: ip: add wilcard support for device matching

[Eric Dumazet]

Le vendredi 10 décembre 2010 à 19:32 +0200, Octavian Purdila a écrit :

> Would allowing escaping it fix the issue? Like:
> 
> ip link add link bond0 "vlan\*" txqueuelen 100 type vlan id 999
> 

Well, same compat problem ;)

$ ip link add link bond0 "vlan\*199" type vlan id 199
$ ifconfig "vlan\*199"
vlan\199  Link encap:Ethernet  HWaddr 00:1E:0B:EC:D3:D2  
          BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

Re: [PATCH] iproute2: ip: add wilcard support for device matching

[Octavian Purdila]

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Friday 10 December 2010, 19:42:39

> Le vendredi 10 décembre 2010 à 19:32 +0200, Octavian Purdila a écrit :
> > Would allowing escaping it fix the issue? Like:
> > 
> > ip link add link bond0 "vlan\*" txqueuelen 100 type vlan id 999
> 
> Well, same compat problem ;)
> 
> $ ip link add link bond0 "vlan\*199" type vlan id 199
> $ ifconfig "vlan\*199"

:) Then use a special dev keyword like dev* ?

$ ip link set dev* dummy set

Or use a new flag to allow expansion?

$ ip -e link set dev dummy* set


Thanks,
tavi

Re: [PATCH] iproute2: ip: add wilcard support for device matching

[jamal]

On Fri, 2010-12-10 at 20:06 +0200, Octavian Purdila wrote:

> > $ ip link add link bond0 "vlan\*199" type vlan id 199
> > $ ifconfig "vlan\*199"
> 
> :) Then use a special dev keyword like dev* ?
> 
> $ ip link set dev* dummy set
> 
> Or use a new flag to allow expansion?
> 
> $ ip -e link set dev dummy* set

There was something ive always wanted to do but
havent had time. It will cut time in a big way the
user-kernel interaction in precisely your situation.

Add a new general purpose netdev 32 bit tag. You can use this
feature to "group" netdevs. The group "all netdevs" is 0 - which
is the default.
I can group individual dummy interfaces into group 1. 
ip link dev dummy0 set group 1
..
..
ip link dev dummy99 set group 1

Then i can send a query to only ifup and ignore
the 1000 vlans that exist.

ip link dev ls group 1

or if i didnt list the group, then group 0 is assumed.

As a warning - this would be a general purpose tag.
So i can use it in conjunction with skb->mark to enable
filtering for example on ingress side with some action.

cheers,
jamal

Re: [PATCH] iproute2: ip: add wilcard support for device matching

[Vlad Dogaru]

On 12/17/2010 5:38 AM, jamal wrote:
> On Fri, 2010-12-10 at 20:06 +0200, Octavian Purdila wrote:
>
>>> $ ip link add link bond0 "vlan\*199" type vlan id 199
>>> $ ifconfig "vlan\*199"
>>
>> :) Then use a special dev keyword like dev* ?
>>
>> $ ip link set dev* dummy set
>>
>> Or use a new flag to allow expansion?
>>
>> $ ip -e link set dev dummy* set
>
> There was something ive always wanted to do but
> havent had time. It will cut time in a big way the
> user-kernel interaction in precisely your situation.
>
> Add a new general purpose netdev 32 bit tag. You can use this
> feature to "group" netdevs. The group "all netdevs" is 0 - which
> is the default.
> I can group individual dummy interfaces into group 1.
> ip link dev dummy0 set group 1
> ..
> ..
> ip link dev dummy99 set group 1
>
> Then i can send a query to only ifup and ignore
> the 1000 vlans that exist.
>
> ip link dev ls group 1
>
> or if i didnt list the group, then group 0 is assumed.

I'll try to implement this approach in the next few days.

Vlad

Re: [PATCH] iproute2: ip: add wilcard support for device matching

[jamal]

On Mon, 2010-12-20 at 11:23 -0800, Vlad Dogaru wrote:

> I'll try to implement this approach in the next few days.

Excellent ;-> Remember, this is general purpose tag, sort
like socket/route/skb->mark. It is upto the administrator to
define its use via policy. 

cheers,
jamal

Re: [PATCH] iproute2: ip: add wilcard support for device matching

[Philip Prindeville]

On 12/21/10 5:14 AM, jamal wrote:
> On Mon, 2010-12-20 at 11:23 -0800, Vlad Dogaru wrote:
>
>> I'll try to implement this approach in the next few days.
> Excellent ;->  Remember, this is general purpose tag, sort
> like socket/route/skb->mark. It is upto the administrator to
> define its use via policy.
>
> cheers,
> jamal


Did that end up going anywhere?

There are a lot of cases where matching on "ppp*" would be handy.