Subject: Re: [PATCH iproute2] Add passthru mode and support 'mode' parameter with macvtap devices

From: Arnd Bergmann <[email-masked]>
Date: Wed, 27 Oct 2010 16:00:43 +0200

On Wednesday 27 October 2010, Sridhar Samudrala wrote:
> Support a new 'passthru' mode with macvlan and 'mode' parameter
> with macvtap devices.
> 
> Signed-off-by: Sridhar Samudrala <[email-masked]>

Can you split this into two patches?

We definitely want the part adding support for macvtap device mode
setting now. The new passthru mode for macvlan and macvtap probably
needs some discussion and the patch in iproute2 will depends on
the kernel patch getting merged first.

I've added Stephen to the Cc list, he should also take a look.

	Arnd

> diff --git a/include/linux/if_link.h b/include/linux/if_link.h
> index f5bb2dc..23de79e 100644
> --- a/include/linux/if_link.h
> +++ b/include/linux/if_link.h
> @@ -230,6 +230,7 @@ enum macvlan_mode {
>  	MACVLAN_MODE_PRIVATE = 1, /* don't talk to other macvlans */
>  	MACVLAN_MODE_VEPA    = 2, /* talk to other ports through ext bridge */
>  	MACVLAN_MODE_BRIDGE  = 4, /* talk to bridge ports directly */
> +	MACVLAN_MODE_PASSTHRU  = 8, /* take over the underlying device */
>  };
>  
>  /* SR-IOV virtual function management section */
> diff --git a/ip/Makefile b/ip/Makefile
> index 2f223ca..6054e8a 100644
> --- a/ip/Makefile
> +++ b/ip/Makefile
> @@ -3,7 +3,7 @@ IPOBJ=ip.o ipaddress.o ipaddrlabel.o iproute.o iprule.o \
>      ipmaddr.o ipmonitor.o ipmroute.o ipprefix.o iptuntap.o \
>      ipxfrm.o xfrm_state.o xfrm_policy.o xfrm_monitor.o \
>      iplink_vlan.o link_veth.o link_gre.o iplink_can.o \
> -    iplink_macvlan.o
> +    iplink_macvlan.o iplink_macvtap.o
>  
>  RTMONOBJ=rtmon.o
>  
> diff --git a/ip/iplink_macvlan.c b/ip/iplink_macvlan.c
> index a3c78bd..97787f9 100644
> --- a/ip/iplink_macvlan.c
> +++ b/ip/iplink_macvlan.c
> @@ -48,6 +48,8 @@ static int macvlan_parse_opt(struct link_util *lu, int argc, char **argv,
>  				mode = MACVLAN_MODE_VEPA;
>  			else if (strcmp(*argv, "bridge") == 0)
>  				mode = MACVLAN_MODE_BRIDGE;
> +			else if (strcmp(*argv, "passthru") == 0)
> +				mode = MACVLAN_MODE_PASSTHRU;
>  			else
>  				return mode_arg();
>  
> @@ -82,6 +84,7 @@ static void macvlan_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[]
>  		  mode == MACVLAN_MODE_PRIVATE ? "private"
>  		: mode == MACVLAN_MODE_VEPA    ? "vepa"
>  		: mode == MACVLAN_MODE_BRIDGE  ? "bridge"
> +		: mode == MACVLAN_MODE_PASSTHRU  ? "passthru"
>  		:				 "unknown");
>  }
>  
> diff --git a/ip/iplink_macvtap.c b/ip/iplink_macvtap.c
> new file mode 100644
> index 0000000..040cc68
> --- /dev/null
> +++ b/ip/iplink_macvtap.c
> @@ -0,0 +1,93 @@
> +/*
> + * iplink_macvtap.c	macvtap device support
> + *
> + *              This program is free software; you can redistribute it and/or
> + *              modify it under the terms of the GNU General Public License
> + *              as published by the Free Software Foundation; either version
> + *              2 of the License, or (at your option) any later version.
> + */
> +
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <sys/socket.h>
> +#include <linux/if_link.h>
> +
> +#include "rt_names.h"
> +#include "utils.h"
> +#include "ip_common.h"
> +
> +static void explain(void)
> +{
> +	fprintf(stderr,
> +		"Usage: ... macvtap mode { private | vepa | bridge | passthru }\n"
> +	);
> +}
> +
> +static int mode_arg(void)
> +{
> +        fprintf(stderr, "Error: argument of \"mode\" must be \"private\", "
> +		"\"vepa\" or \"bridge\" \"passthru\"\n");
> +        return -1;
> +}
> +
> +static int macvtap_parse_opt(struct link_util *lu, int argc, char **argv,
> +			  struct nlmsghdr *n)
> +{
> +	while (argc > 0) {
> +		if (matches(*argv, "mode") == 0) {
> +			__u32 mode = 0;
> +			NEXT_ARG();
> +
> +			if (strcmp(*argv, "private") == 0)
> +				mode = MACVLAN_MODE_PRIVATE;
> +			else if (strcmp(*argv, "vepa") == 0)
> +				mode = MACVLAN_MODE_VEPA;
> +			else if (strcmp(*argv, "bridge") == 0)
> +				mode = MACVLAN_MODE_BRIDGE;
> +			else if (strcmp(*argv, "passthru") == 0)
> +				mode = MACVLAN_MODE_PASSTHRU;
> +			else
> +				return mode_arg();
> +
> +			addattr32(n, 1024, IFLA_MACVLAN_MODE, mode);
> +		} else if (matches(*argv, "help") == 0) {
> +			explain();
> +			return -1;
> +		} else {
> +			fprintf(stderr, "macvtap: what is \"%s\"?\n", *argv);
> +			explain();
> +			return -1;
> +		}
> +		argc--, argv++;
> +	}
> +
> +	return 0;
> +}
> +
> +static void macvtap_print_opt(struct link_util *lu, FILE *f, struct rtattr *tb[])
> +{
> +	__u32 mode;
> +
> +	if (!tb)
> +		return;
> +
> +	if (!tb[IFLA_MACVLAN_MODE] ||
> +	    RTA_PAYLOAD(tb[IFLA_MACVLAN_MODE]) < sizeof(__u32))
> +		return;
> +
> +	mode = *(__u32 *)RTA_DATA(tb[IFLA_VLAN_ID]);
> +	fprintf(f, " mode %s ",
> +		  mode == MACVLAN_MODE_PRIVATE ? "private"
> +		: mode == MACVLAN_MODE_VEPA    ? "vepa"
> +		: mode == MACVLAN_MODE_BRIDGE  ? "bridge"
> +		: mode == MACVLAN_MODE_PASSTHRU  ? "passthru"
> +		:				 "unknown");
> +}
> +
> +struct link_util macvtap_link_util = {
> +	.id		= "macvtap",
> +	.maxattr	= IFLA_MACVLAN_MAX,
> +	.parse_opt	= macvtap_parse_opt,
> +	.print_opt	= macvtap_print_opt,
> +};
> 
> 
>