Allow user to set metric on default route learned via Router Advertisement.
Note: RFC 4191 does not say anything for metric for IPv6 default route.
Fix:
For IPv4, default route is learned via DHCPv4 and user is allowed to change
metric using config in 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.
Logs:
----------------------------------------------------------------
For IPv4:
----------------------------------------------------------------
Config in etc/network/interfaces
----------------------------------------------------------------
```
auto eth0
iface eth0 inet dhcp
metric 4261413864
```
IPv4 Kernel Route Table:
----------------------------------------------------------------
```
$ sudo route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 172.11.44.1 0.0.0.0 UG -33553432 0 0 eth0
```
FRR Table, if a static route is configured. [In real scenario, it is useful to prefer BGP learned default route over DHCPv4 default route.]
----------------------------------------------------------------
```
Codes: K - kernel route, C - connected, S - static, R - RIP,
O - OSPF, I - IS-IS, B - BGP, P - PIM, E - EIGRP, N - NHRP,
T - Table, v - VNC, V - VNC-Direct, A - Babel, D - SHARP,
> - selected route, * - FIB route
S>* 0.0.0.0/0 [20/0] is directly connected, eth0, 00:00:03
K 0.0.0.0/0 [254/1000] via 172.21.47.1, eth0, 6d08h51m
```
----------------------------------------------------------------
i.e. User can prefer Default Router learned via Routing Protocol,
Similar behavior is not possible for IPv6, without this fix.
----------------------------------------------------------------
After fix [for IPv6]:
----------------------------------------------------------------
```
sudo sysctl -w net.ipv6.conf.eth0.net.ipv6.conf.eth0.accept_ra_defrtr_metric=0x770003e9
```
IP monitor:
----------------------------------------------------------------
```
default via fe80::xx16:xxxx:feb3:ce8e dev eth0 proto ra metric 1996489705 pref high
```
Kernel IPv6 routing table
----------------------------------------------------------------
```
Destination Next Hop Flag Met Ref Use If
::/0 fe80::xx16:xxxx:feb3:ce8e UGDAe 1996489705 0
0 eth0
```
FRR Table, if a static route is configured. [In real scenario, it is useful to prefer BGP learned default route over IPv6 RA default route.]
```
----------------------------------------------------------------
Codes: K - kernel route, C - connected, S - static, R - RIPng,
O - OSPFv3, I - IS-IS, B - BGP, N - NHRP, T - Table,
v - VNC, V - VNC-Direct, A - Babel, D - SHARP,
> - selected route, * - FIB route
S>* ::/0 [20/0] is directly connected, eth0, 00:00:06
K ::/0 [119/1001] via fe80::xx16:xxxx:feb3:ce8e, eth0, 6d07h43m
----------------------------------------------------------------
```
If the metric is changed later, the effect will be seen only when IPv6 RA is received, because the default route must be fully controlled by RA msg.
```
admin@lnos-x1-a-asw03:~$ sudo sysctl -w net.ipv6.conf.eth0.accept_ra_defrtr_metric=0x770003e8
net.ipv6.conf.eth0.accept_ra_defrtr_metric = 0x770003e8
```
IP monitor: when metric is changed after learning Default Route from previous IPv6 RA msg:
```
Deleted default via fe80::xx16:xxxx:feb3:ce8e dev eth0 proto ra metric 1996489705 expires 3sec hoplimit 64 pref high
default via fe80::xx16:xxxx:feb3:ce8e dev eth0 proto ra metric 1996489704 pref high
```
Praveen Chaudhary (1):
Allow user to set metric on default route learned via Router
Advertisement.
Documentation/networking/ip-sysctl.rst | 18 ++++++++++++++++++
include/linux/ipv6.h | 1 +
include/net/ip6_route.h | 3 ++-
include/uapi/linux/ipv6.h | 1 +
include/uapi/linux/sysctl.h | 1 +
net/ipv6/addrconf.c | 10 ++++++++++
net/ipv6/ndisc.c | 14 ++++++++++----
net/ipv6/route.c | 5 +++--
8 files changed, 46 insertions(+), 7 deletions(-)
base-commit: 139711f033f636cc78b6aaf7363252241b9698ef
--
2.29.0
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<[email protected]>
Signed-off-by: Zhenggen Xu<[email protected]>
Changes in v1.
---
1.) Correct the call to rt6_add_dflt_router.
---
---
Documentation/networking/ip-sysctl.rst | 18 ++++++++++++++++++
include/linux/ipv6.h | 1 +
include/net/ip6_route.h | 3 ++-
include/uapi/linux/ipv6.h | 1 +
include/uapi/linux/sysctl.h | 1 +
net/ipv6/addrconf.c | 10 ++++++++++
net/ipv6/ndisc.c | 14 ++++++++++----
net/ipv6/route.c | 5 +++--
8 files changed, 46 insertions(+), 7 deletions(-)
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index dd2b12a32b73..384159081d91 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -1871,6 +1871,24 @@ accept_ra_defrtr - BOOLEAN
- enabled if accept_ra is enabled.
- disabled if accept_ra is disabled.
+accept_ra_defrtr_metric - INTEGER
+ Route metric for default route learned in Router Advertisement. This
+ value will be assigned as metric for the route learned via IPv6 Router
+ Advertisement.
+
+ Possible values are:
+ 0:
+ Use default value i.e. IP6_RT_PRIO_USER 1024.
+ 0xFFFFFFFF to -1:
+ -ve values represent high route metric, value will be treated as
+ unsigned value. This behaviour is inline with current IPv4 metric
+ shown with commands such as "route -n" or "ip route list".
+ 1 to 0x7FFFFFF:
+ +ve values will be used as is for route metric.
+
+ Functional default: enabled if accept_ra_defrtr is enabled.
+ disabled if accept_ra_defrtr is disabled.
+
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/include/linux/ipv6.h b/include/linux/ipv6.h
index dda61d150a13..19af90c77200 100644
--- a/include/linux/ipv6.h
+++ b/include/linux/ipv6.h
@@ -31,6 +31,7 @@ struct ipv6_devconf {
__s32 max_desync_factor;
__s32 max_addresses;
__s32 accept_ra_defrtr;
+ __s32 accept_ra_defrtr_metric;
__s32 accept_ra_min_hop_limit;
__s32 accept_ra_pinfo;
__s32 ignore_routes_with_linkdown;
diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
index 2a5277758379..a470bdab2420 100644
--- a/include/net/ip6_route.h
+++ b/include/net/ip6_route.h
@@ -174,7 +174,8 @@ struct fib6_info *rt6_get_dflt_router(struct net *net,
struct net_device *dev);
struct fib6_info *rt6_add_dflt_router(struct net *net,
const struct in6_addr *gwaddr,
- struct net_device *dev, unsigned int pref);
+ struct net_device *dev, unsigned int pref,
+ unsigned int defrtr_usr_metric);
void rt6_purge_dflt_routers(struct net *net);
diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h
index 13e8751bf24a..945de5de5144 100644
--- a/include/uapi/linux/ipv6.h
+++ b/include/uapi/linux/ipv6.h
@@ -189,6 +189,7 @@ enum {
DEVCONF_ACCEPT_RA_RT_INFO_MIN_PLEN,
DEVCONF_NDISC_TCLASS,
DEVCONF_RPL_SEG_ENABLED,
+ DEVCONF_ACCEPT_RA_DEFRTR_METRIC,
DEVCONF_MAX
};
diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h
index 458179df9b27..5e79c196e33c 100644
--- a/include/uapi/linux/sysctl.h
+++ b/include/uapi/linux/sysctl.h
@@ -571,6 +571,7 @@ enum {
NET_IPV6_ACCEPT_SOURCE_ROUTE=25,
NET_IPV6_ACCEPT_RA_FROM_LOCAL=26,
NET_IPV6_ACCEPT_RA_RT_INFO_MIN_PLEN=27,
+ NET_IPV6_ACCEPT_RA_DEFRTR_METRIC=28,
__NET_IPV6_MAX
};
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index eff2cacd5209..702ec4a33936 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,
+ .accept_ra_defrtr_metric = 0,
.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,
+ .accept_ra_defrtr_metric = 0,
.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_ACCEPT_RA_DEFRTR_METRIC] = cnf->accept_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 = "accept_ra_defrtr_metric",
+ .data = &ipv6_devconf.accept_ra_defrtr_metric,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
{
.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..96ab202e95f9 100644
--- a/net/ipv6/ndisc.c
+++ b/net/ipv6/ndisc.c
@@ -1180,6 +1180,7 @@ static void ndisc_router_discovery(struct sk_buff *skb)
unsigned int pref = 0;
__u32 old_if_flags;
bool send_ifinfo_notify = false;
+ unsigned int defrtr_usr_metric = 0;
__u8 *opt = (__u8 *)(ra_msg + 1);
@@ -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;
+ if (defrtr_usr_metric == 0)
+ defrtr_usr_metric = IP6_RT_PRIO_USER;
+ /* delete the route if lifetime is 0 or if metric needs change */
+ if (rt && ((lifetime == 0) || (rt->fib6_metric != defrtr_usr_metric))) {
ip6_del_rt(net, rt, false);
rt = NULL;
}
- ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, for dev: %s\n",
- rt, lifetime, skb->dev->name);
+ ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n",
+ rt, lifetime, defrtr_usr_metric, skb->dev->name);
if (!rt && lifetime) {
ND_PRINTK(3, info, "RA: adding default router\n");
rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
- skb->dev, pref);
+ skb->dev, pref, defrtr_usr_metric);
if (!rt) {
ND_PRINTK(0, err,
"RA: %s failed to add default route\n",
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 188e114b29b4..5f177ae97e42 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -4252,11 +4252,12 @@ struct fib6_info *rt6_get_dflt_router(struct net *net,
struct fib6_info *rt6_add_dflt_router(struct net *net,
const struct in6_addr *gwaddr,
struct net_device *dev,
- unsigned int pref)
+ unsigned int pref,
+ unsigned int defrtr_usr_metric)
{
struct fib6_config cfg = {
.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
- .fc_metric = IP6_RT_PRIO_USER,
+ .fc_metric = defrtr_usr_metric ? defrtr_usr_metric : IP6_RT_PRIO_USER,
.fc_ifindex = dev->ifindex,
.fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
--
2.29.0
On 1/12/21 6:50 PM, 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.
This is a single patch set, so the details you have in the cover letter
should be in this description here. Also, please just 'ip' commands in
the patch description; 'route' command is a dinosaur that needs to be
retired.
>
> Signed-off-by: Praveen Chaudhary<[email protected]>
> Signed-off-by: Zhenggen Xu<[email protected]>
>
> Changes in v1.
> ---
> 1.) Correct the call to rt6_add_dflt_router.
> ---
>
> ---
> Documentation/networking/ip-sysctl.rst | 18 ++++++++++++++++++
> include/linux/ipv6.h | 1 +
> include/net/ip6_route.h | 3 ++-
> include/uapi/linux/ipv6.h | 1 +
> include/uapi/linux/sysctl.h | 1 +
> net/ipv6/addrconf.c | 10 ++++++++++
> net/ipv6/ndisc.c | 14 ++++++++++----
> net/ipv6/route.c | 5 +++--
> 8 files changed, 46 insertions(+), 7 deletions(-)
>
> diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
> index dd2b12a32b73..384159081d91 100644
> --- a/Documentation/networking/ip-sysctl.rst
> +++ b/Documentation/networking/ip-sysctl.rst
> @@ -1871,6 +1871,24 @@ accept_ra_defrtr - BOOLEAN
> - enabled if accept_ra is enabled.
> - disabled if accept_ra is disabled.
>
> +accept_ra_defrtr_metric - INTEGER
Drop the 'accept' part; ra_defrtr_metric is sufficiently long. Since the
value is not from the RA, it is not really about accepting data from the RA.
> + Route metric for default route learned in Router Advertisement. This
> + value will be assigned as metric for the route learned via IPv6 Router
> + Advertisement.
> +
> + Possible values are:
> + 0:
> + Use default value i.e. IP6_RT_PRIO_USER 1024.
> + 0xFFFFFFFF to -1:
> + -ve values represent high route metric, value will be treated as
> + unsigned value. This behaviour is inline with current IPv4 metric
> + shown with commands such as "route -n" or "ip route list".
> + 1 to 0x7FFFFFF:
> + +ve values will be used as is for route metric.
route metric is a u32, so these ranges should not be needed. 'ip route
list' shows metric as a positive number only.
> +
> + Functional default: enabled if accept_ra_defrtr is enabled.
> + disabled if accept_ra_defrtr is disabled.
Alignment problem, but I think this can be moved above to the
description and changed to something like 'only takes affect if
accept_ra_defrtr' is enabled.
> +
> 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/include/linux/ipv6.h b/include/linux/ipv6.h
> index dda61d150a13..19af90c77200 100644
> --- a/include/linux/ipv6.h
> +++ b/include/linux/ipv6.h
> @@ -31,6 +31,7 @@ struct ipv6_devconf {
> __s32 max_desync_factor;
> __s32 max_addresses;
> __s32 accept_ra_defrtr;
> + __s32 accept_ra_defrtr_metric;
__u32 and drop the 'accept_' prefix.
> __s32 accept_ra_min_hop_limit;
> __s32 accept_ra_pinfo;
> __s32 ignore_routes_with_linkdown;
> diff --git a/include/net/ip6_route.h b/include/net/ip6_route.h
> index 2a5277758379..a470bdab2420 100644
> --- a/include/net/ip6_route.h
> +++ b/include/net/ip6_route.h
> @@ -174,7 +174,8 @@ struct fib6_info *rt6_get_dflt_router(struct net *net,
> struct net_device *dev);
> struct fib6_info *rt6_add_dflt_router(struct net *net,
> const struct in6_addr *gwaddr,
> - struct net_device *dev, unsigned int pref);
> + struct net_device *dev, unsigned int pref,
> + unsigned int defrtr_usr_metric);
u32 for consistency
>
> void rt6_purge_dflt_routers(struct net *net);
>
> diff --git a/include/uapi/linux/ipv6.h b/include/uapi/linux/ipv6.h
> index 13e8751bf24a..945de5de5144 100644
> --- a/include/uapi/linux/ipv6.h
> +++ b/include/uapi/linux/ipv6.h
> @@ -189,6 +189,7 @@ enum {
> DEVCONF_ACCEPT_RA_RT_INFO_MIN_PLEN,
> DEVCONF_NDISC_TCLASS,
> DEVCONF_RPL_SEG_ENABLED,
> + DEVCONF_ACCEPT_RA_DEFRTR_METRIC,
Drop 'ACCEPT_'
> DEVCONF_MAX
> };
>
> diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h
> index 458179df9b27..5e79c196e33c 100644
> --- a/include/uapi/linux/sysctl.h
> +++ b/include/uapi/linux/sysctl.h
> @@ -571,6 +571,7 @@ enum {
> NET_IPV6_ACCEPT_SOURCE_ROUTE=25,
> NET_IPV6_ACCEPT_RA_FROM_LOCAL=26,
> NET_IPV6_ACCEPT_RA_RT_INFO_MIN_PLEN=27,
> + NET_IPV6_ACCEPT_RA_DEFRTR_METRIC=28,
Drop 'ACCEPT_'
> __NET_IPV6_MAX
> };
>
> diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
> index eff2cacd5209..702ec4a33936 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,
> + .accept_ra_defrtr_metric = 0,
> .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,
> + .accept_ra_defrtr_metric = 0,
> .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_ACCEPT_RA_DEFRTR_METRIC] = cnf->accept_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 = "accept_ra_defrtr_metric",
> + .data = &ipv6_devconf.accept_ra_defrtr_metric,
> + .maxlen = sizeof(int),
> + .mode = 0644,
> + .proc_handler = proc_dointvec,
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..96ab202e95f9 100644
> --- a/net/ipv6/ndisc.c
> +++ b/net/ipv6/ndisc.c
> @@ -1180,6 +1180,7 @@ static void ndisc_router_discovery(struct sk_buff *skb)
> unsigned int pref = 0;
> __u32 old_if_flags;
> bool send_ifinfo_notify = false;
> + unsigned int defrtr_usr_metric = 0;
net coding style is reverse xmas tree - ie., longest to shortest. yes,
this function is old school, but new entries can be added in the right
place. Since you set before use, the initialization to 0 is not
necessary. And u32 for consistency.
>
> __u8 *opt = (__u8 *)(ra_msg + 1);
>
> @@ -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;
> + if (defrtr_usr_metric == 0)
> + defrtr_usr_metric = IP6_RT_PRIO_USER;
> + /* delete the route if lifetime is 0 or if metric needs change */
> + if (rt && ((lifetime == 0) || (rt->fib6_metric != defrtr_usr_metric))) {
> ip6_del_rt(net, rt, false);
> rt = NULL;
> }
>
> - ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, for dev: %s\n",
> - rt, lifetime, skb->dev->name);
> + ND_PRINTK(3, info, "RA: rt: %p lifetime: %d, metric: %d, for dev: %s\n",
> + rt, lifetime, defrtr_usr_metric, skb->dev->name);
> if (!rt && lifetime) {
> ND_PRINTK(3, info, "RA: adding default router\n");
>
> rt = rt6_add_dflt_router(net, &ipv6_hdr(skb)->saddr,
> - skb->dev, pref);
> + skb->dev, pref, defrtr_usr_metric);
> if (!rt) {
> ND_PRINTK(0, err,
> "RA: %s failed to add default route\n",
> diff --git a/net/ipv6/route.c b/net/ipv6/route.c
> index 188e114b29b4..5f177ae97e42 100644
> --- a/net/ipv6/route.c
> +++ b/net/ipv6/route.c
> @@ -4252,11 +4252,12 @@ struct fib6_info *rt6_get_dflt_router(struct net *net,
> struct fib6_info *rt6_add_dflt_router(struct net *net,
> const struct in6_addr *gwaddr,
> struct net_device *dev,
> - unsigned int pref)
> + unsigned int pref,
> + unsigned int defrtr_usr_metric)
u32
> {
> struct fib6_config cfg = {
> .fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
> - .fc_metric = IP6_RT_PRIO_USER,
> + .fc_metric = defrtr_usr_metric ? defrtr_usr_metric : IP6_RT_PRIO_USER,
you can abbreviate that as:
defrtr_usr_metric ? : IP6_RT_PRIO_USER,
> .fc_ifindex = dev->ifindex,
> .fc_flags = RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
> RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
>
Hi David
Thanks a lot for Review,
I have raised v2 after addressing your review comments from
https://lkml.org/lkml/2021/1/14/1400.
List of changes in v2:
---
1.) Replace accept_ra_defrtr_metric with 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.
---
Thanks a lot again for help.