On 1/15/21 1:02 AM, Praveen Chaudhary wrote:
> For IPv4, default route is learned via DHCPv4 and user is allowed to change
> metric using config etc/network/interfaces. But for IPv6, default route can
> be learned via RA, for which, currently a fixed metric value 1024 is used.
>
> Ideally, user should be able to configure metric on default route for IPv6
> similar to IPv4. This fix adds sysctl for the same.
>
> Signed-off-by: Praveen Chaudhary <pchaudh...@linkedin.com>
> Signed-off-by: Zhenggen Xu <z...@linkedin.com>
>
> Changes in v1.
> ---
your trying to be too fancy in the log messages; everything after this
first '---' is dropped. Just Remove all of the '---' lines and '```' tags.
> 1.) Correct the call to rt6_add_dflt_router.
> ---
>
> Changes in v2.
> [Refer: lkml.org/lkml/2021/1/14/1400]
> ---
> 1.) Replace accept_ra_defrtr_metric to ra_defrtr_metric.
> 2.) Change Type to __u32 instead of __s32.
> 3.) Change description in Documentation/networking/ip-sysctl.rst.
> 4.) Use proc_douintvec instead of proc_dointvec.
> 5.) Code style in ndisc_router_discovery().
> 6.) Change Type to u32 instead of unsigned int.
> ---
>
> Logs:
> ----------------------------------------------------------------
> For IPv4:
> ----------------------------------------------------------------
>
> Config in etc/network/interfaces
> ----------------------------------------------------------------
> ```
> auto eth0
> iface eth0 inet dhcp
> metric 4261413864
how does that work for IPv4? Is the metric passed to the dhclient and it
inserts the route with the given metric or is a dhclient script used to
replace the route after insert?
> diff --git a/Documentation/networking/ip-sysctl.rst
> b/Documentation/networking/ip-sysctl.rst
> index dd2b12a32b73..c4b8d4b8d213 100644
> --- a/Documentation/networking/ip-sysctl.rst
> +++ b/Documentation/networking/ip-sysctl.rst
> @@ -1871,6 +1871,18 @@ accept_ra_defrtr - BOOLEAN
> - enabled if accept_ra is enabled.
> - disabled if accept_ra is disabled.
>
> +ra_defrtr_metric - INTEGER
> + Route metric for default route learned in Router Advertisement. This
> value
> + will be assigned as metric for the default route learned via IPv6 Router
> + Advertisement. Takes affect only if accept_ra_defrtr' is enabled.
stray ' after accept_ra_defrtr
> +
> + Possible values are:
> + 0:
> + default value will be used for route metric
> + i.e. IP6_RT_PRIO_USER 1024.
> + 1 to 0xFFFFFFFF:
> + current value will be used for route metric.
> +
> accept_ra_from_local - BOOLEAN
> Accept RA with source-address that is found on local machine
> if the RA is otherwise proper and able to be accepted.
> diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
> index eff2cacd5209..b13d3213e58f 100644
> --- a/net/ipv6/addrconf.c
> +++ b/net/ipv6/addrconf.c
> @@ -205,6 +205,7 @@ static struct ipv6_devconf ipv6_devconf __read_mostly = {
> .max_desync_factor = MAX_DESYNC_FACTOR,
> .max_addresses = IPV6_MAX_ADDRESSES,
> .accept_ra_defrtr = 1,
> + .ra_defrtr_metric = 0,
make the the '=' align column wise with the existing entries; seems like
your new line is missing a tab
> .accept_ra_from_local = 0,
> .accept_ra_min_hop_limit= 1,
> .accept_ra_pinfo = 1,
> @@ -260,6 +261,7 @@ static struct ipv6_devconf ipv6_devconf_dflt
> __read_mostly = {
> .max_desync_factor = MAX_DESYNC_FACTOR,
> .max_addresses = IPV6_MAX_ADDRESSES,
> .accept_ra_defrtr = 1,
> + .ra_defrtr_metric = 0,
same here
> .accept_ra_from_local = 0,
> .accept_ra_min_hop_limit= 1,
> .accept_ra_pinfo = 1,
> @@ -5475,6 +5477,7 @@ static inline void ipv6_store_devconf(struct
> ipv6_devconf *cnf,
> array[DEVCONF_MAX_DESYNC_FACTOR] = cnf->max_desync_factor;
> array[DEVCONF_MAX_ADDRESSES] = cnf->max_addresses;
> array[DEVCONF_ACCEPT_RA_DEFRTR] = cnf->accept_ra_defrtr;
> + array[DEVCONF_RA_DEFRTR_METRIC] = cnf->ra_defrtr_metric;
> array[DEVCONF_ACCEPT_RA_MIN_HOP_LIMIT] = cnf->accept_ra_min_hop_limit;
> array[DEVCONF_ACCEPT_RA_PINFO] = cnf->accept_ra_pinfo;
> #ifdef CONFIG_IPV6_ROUTER_PREF
> @@ -6667,6 +6670,13 @@ static const struct ctl_table addrconf_sysctl[] = {
> .mode = 0644,
> .proc_handler = proc_dointvec,
> },
> + {
> + .procname = "ra_defrtr_metric",
> + .data = &ipv6_devconf.ra_defrtr_metric,
> + .maxlen = sizeof(u32),
> + .mode = 0644,
> + .proc_handler = proc_douintvec,
> + },
> {
> .procname = "accept_ra_min_hop_limit",
> .data = &ipv6_devconf.accept_ra_min_hop_limit,
> diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c
> index 76717478f173..2bffed49f5c0 100644
> --- a/net/ipv6/ndisc.c
> +++ b/net/ipv6/ndisc.c
> @@ -1173,6 +1173,7 @@ static void ndisc_router_discovery(struct sk_buff *skb)
> struct neighbour *neigh = NULL;
> struct inet6_dev *in6_dev;
> struct fib6_info *rt = NULL;
> + u32 defrtr_usr_metric;
> struct net *net;
> int lifetime;
> struct ndisc_options ndopts;
> @@ -1303,18 +1304,23 @@ static void ndisc_router_discovery(struct sk_buff
> *skb)
> return;
> }
> }
> - if (rt && lifetime == 0) {
> + /* Set default route metric if specified by user */
> + defrtr_usr_metric = in6_dev->cnf.accept_ra_defrtr_metric;
this tells me you did not compile this version of the patch since the
'accept_' has been dropped. Always compile and test every patch before
sending.
