ipv6: export function to send route updates

Add fib6_rt_update to send RTM_NEWROUTE with NLM_F_REPLACE set. This
helper will be used by the nexthop code to notify userspace of routes
that are impacted when a nexthop config is updated via replace.

This notification is needed for legacy apps that do not understand
the new nexthop object. Apps that are nexthop aware can use the
RTA_NH_ID attribute in the route notification to just ignore it.

In the future this should be wrapped in a sysctl to allow OS'es that
are fully updated to avoid the notificaton storm.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David Ahern 2019-05-22 12:04:41 -07:00 committed by David S. Miller
parent cdaa16a4f7
commit 19a3b7eea4
5 changed files with 46 additions and 4 deletions

View File

@ -452,6 +452,12 @@ int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
struct netlink_ext_ack *extack);
void fib6_nh_release(struct fib6_nh *fib6_nh);
int call_fib6_entry_notifiers(struct net *net,
enum fib_event_type event_type,
struct fib6_info *rt,
struct netlink_ext_ack *extack);
void fib6_rt_update(struct net *net, struct fib6_info *rt,
struct nl_info *info);
void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
unsigned int flags);

View File

@ -47,6 +47,9 @@ struct ipv6_stub {
void (*fib6_nh_release)(struct fib6_nh *fib6_nh);
void (*fib6_update_sernum)(struct net *net, struct fib6_info *rt);
int (*ip6_del_rt)(struct net *net, struct fib6_info *rt);
void (*fib6_rt_update)(struct net *net, struct fib6_info *rt,
struct nl_info *info);
void (*udpv6_encap_enable)(void);
void (*ndisc_send_na)(struct net_device *dev, const struct in6_addr *daddr,
const struct in6_addr *solicited_addr,

View File

@ -927,6 +927,7 @@ static const struct ipv6_stub ipv6_stub_impl = {
.fib6_nh_init = fib6_nh_init,
.fib6_nh_release = fib6_nh_release,
.fib6_update_sernum = fib6_update_sernum_stub,
.fib6_rt_update = fib6_rt_update,
.ip6_del_rt = ip6_del_rt,
.udpv6_encap_enable = udpv6_encap_enable,
.ndisc_send_na = ndisc_send_na,

View File

@ -393,10 +393,10 @@ static int call_fib6_entry_notifier(struct notifier_block *nb, struct net *net,
return call_fib6_notifier(nb, net, event_type, &info.info);
}
static int call_fib6_entry_notifiers(struct net *net,
enum fib_event_type event_type,
struct fib6_info *rt,
struct netlink_ext_ack *extack)
int call_fib6_entry_notifiers(struct net *net,
enum fib_event_type event_type,
struct fib6_info *rt,
struct netlink_ext_ack *extack)
{
struct fib6_entry_notifier_info info = {
.info.extack = extack,

View File

@ -5123,6 +5123,38 @@ void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
}
void fib6_rt_update(struct net *net, struct fib6_info *rt,
struct nl_info *info)
{
u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
struct sk_buff *skb;
int err = -ENOBUFS;
/* call_fib6_entry_notifiers will be removed when in-kernel notifier
* is implemented and supported for nexthop objects
*/
call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, rt, NULL);
skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
if (!skb)
goto errout;
err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE);
if (err < 0) {
/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
WARN_ON(err == -EMSGSIZE);
kfree_skb(skb);
goto errout;
}
rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
info->nlh, gfp_any());
return;
errout:
if (err < 0)
rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
}
static int ip6_route_dev_notify(struct notifier_block *this,
unsigned long event, void *ptr)
{