Subject: Re: [PATCH iproute2-next] iproute_lwtunnel: allow specifying 'src' for 'encap ip' / 'encap ip6'

From: Stephen Hemminger <[email-masked]>
Date: Fri, 17 Aug 2018 08:00:22 -0700

On Fri, 17 Aug 2018 10:31:34 +0300
Shmulik Ladkani <[email-masked]> wrote:

> This allows the user to specify the LWTUNNEL_IP_SRC/LWTUNNEL_IP6_SRC
> when setting an lwtunnel encapsulation route.
> 
> Signed-off-by: Shmulik Ladkani <[email-masked]>
> ---
>  ip/iproute_lwtunnel.c | 22 ++++++++++++++++++++--
>  1 file changed, 20 insertions(+), 2 deletions(-)
> 
> diff --git a/ip/iproute_lwtunnel.c b/ip/iproute_lwtunnel.c
> index 740da7c6..20d5545c 100644
> --- a/ip/iproute_lwtunnel.c
> +++ b/ip/iproute_lwtunnel.c
> @@ -671,7 +671,7 @@ static int parse_encap_mpls(struct rtattr *rta, size_t len,
>  static int parse_encap_ip(struct rtattr *rta, size_t len,
>  			  int *argcp, char ***argvp)
>  {
> -	int id_ok = 0, dst_ok = 0, tos_ok = 0, ttl_ok = 0;
> +	int id_ok = 0, dst_ok = 0, src_ok = 0, tos_ok = 0, ttl_ok = 0;
>  	char **argv = *argvp;
>  	int argc = *argcp;
>  
> @@ -694,6 +694,15 @@ static int parse_encap_ip(struct rtattr *rta, size_t len,
>  			get_addr(&addr, *argv, AF_INET);
>  			rta_addattr_l(rta, len, LWTUNNEL_IP_DST,
>  				      &addr.data, addr.bytelen);
> +		} else if (strcmp(*argv, "src") == 0) {
> +			inet_prefix addr;
> +
> +			NEXT_ARG();
> +			if (src_ok++)
> +				duparg2("src", *argv);
> +			get_addr(&addr, *argv, AF_INET);
> +			rta_addattr_l(rta, len, LWTUNNEL_IP_SRC,
> +				      &addr.data, addr.bytelen);
>  		} else if (strcmp(*argv, "tos") == 0) {
>  			__u32 tos;
>  
> @@ -805,7 +814,7 @@ static int parse_encap_ila(struct rtattr *rta, size_t len,
>  static int parse_encap_ip6(struct rtattr *rta, size_t len,
>  			   int *argcp, char ***argvp)
>  {
> -	int id_ok = 0, dst_ok = 0, tos_ok = 0, ttl_ok = 0;
> +	int id_ok = 0, dst_ok = 0, src_ok = 0, tos_ok = 0, ttl_ok = 0;
>  	char **argv = *argvp;
>  	int argc = *argcp;
>  
> @@ -828,6 +837,15 @@ static int parse_encap_ip6(struct rtattr *rta, size_t len,
>  			get_addr(&addr, *argv, AF_INET6);
>  			rta_addattr_l(rta, len, LWTUNNEL_IP6_DST,
>  				      &addr.data, addr.bytelen);
> +		} else if (strcmp(*argv, "src") == 0) {
> +			inet_prefix addr;
> +
> +			NEXT_ARG();
> +			if (src_ok++)
> +				duparg2("src", *argv);
> +			get_addr(&addr, *argv, AF_INET6);
> +			rta_addattr_l(rta, len, LWTUNNEL_IP6_SRC,
> +				      &addr.data, addr.bytelen);
>  		} else if (strcmp(*argv, "tc") == 0) {
>  			__u32 tc;
>  

If you accept an attribute on input you need to parse it and display it the
same way in the show command.