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net: ipv6: Use passed in table for nexthop lookups 

Similar to 3bfd847203 ("net: Use passed in table for nexthop lookups")
for IPv4, if the route spec contains a table id use that to lookup the
next hop first and fall back to a full lookup if it fails (per the fix
4c9bcd1179 ("net: Fix nexthop lookups")).

Example:

    root@kenny:~# ip -6 ro ls table red
    local 2100:1::1 dev lo  proto none  metric 0  pref medium
    2100:1::/120 dev eth1  proto kernel  metric 256  pref medium
    local 2100:2::1 dev lo  proto none  metric 0  pref medium
    2100:2::/120 dev eth2  proto kernel  metric 256  pref medium
    local fe80::e0:f9ff:fe09:3cac dev lo  proto none  metric 0  pref medium
    local fe80::e0:f9ff:fe1c:b974 dev lo  proto none  metric 0  pref medium
    fe80::/64 dev eth1  proto kernel  metric 256  pref medium
    fe80::/64 dev eth2  proto kernel  metric 256  pref medium
    ff00::/8 dev red  metric 256  pref medium
    ff00::/8 dev eth1  metric 256  pref medium
    ff00::/8 dev eth2  metric 256  pref medium
    unreachable default dev lo  metric 240  error -113 pref medium

    root@kenny:~# ip -6 ro add table red 2100:3::/64 via 2100:1::64
    RTNETLINK answers: No route to host

Route add fails even though 2100:1::64 is a reachable next hop:
    root@kenny:~# ping6 -I red  2100:1::64
    ping6: Warning: source address might be selected on device other than red.
    PING 2100:1::64(2100:1::64) from 2100:1::1 red: 56 data bytes
    64 bytes from 2100:1::64: icmp_seq=1 ttl=64 time=1.33 ms

With this patch:
    root@kenny:~# ip -6 ro add table red 2100:3::/64 via 2100:1::64
    root@kenny:~# ip -6 ro ls table red
    local 2100:1::1 dev lo  proto none  metric 0  pref medium
    2100:1::/120 dev eth1  proto kernel  metric 256  pref medium
    local 2100:2::1 dev lo  proto none  metric 0  pref medium
    2100:2::/120 dev eth2  proto kernel  metric 256  pref medium
    2100:3::/64 via 2100:1::64 dev eth1  metric 1024  pref medium
    local fe80::e0:f9ff:fe09:3cac dev lo  proto none  metric 0  pref medium
    local fe80::e0:f9ff:fe1c:b974 dev lo  proto none  metric 0  pref medium
    fe80::/64 dev eth1  proto kernel  metric 256  pref medium
    fe80::/64 dev eth2  proto kernel  metric 256  pref medium
    ff00::/8 dev red  metric 256  pref medium
    ff00::/8 dev eth1  metric 256  pref medium
    ff00::/8 dev eth2  metric 256  pref medium
    unreachable default dev lo  metric 240  error -113 pref medium

Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David Ahern 2016-04-24 21:26:04 -07:00 committed by David S. Miller
parent 570d8e9398
commit 8c14586fc3
1 changed files with 38 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
net/ipv6/route.c
View File

@ -1769,6 +1769,37 @@ static int ip6_convert_metrics(struct mx6_config *mxc,
return -EINVAL;
}
static struct rt6_info *ip6_nh_lookup_table(struct net *net,
struct fib6_config *cfg,
const struct in6_addr *gw_addr)
{
struct flowi6 fl6 = {
.flowi6_oif = cfg->fc_ifindex,
.daddr = *gw_addr,
.saddr = cfg->fc_prefsrc,
};
struct fib6_table *table;
struct rt6_info *rt;
int flags = 0;
table = fib6_get_table(net, cfg->fc_table);
if (!table)
return NULL;
if (!ipv6_addr_any(&cfg->fc_prefsrc))
flags |= RT6_LOOKUP_F_HAS_SADDR;
rt = ip6_pol_route(net, table, cfg->fc_ifindex, &fl6, flags);
/* if table lookup failed, fall back to full lookup */
if (rt == net->ipv6.ip6_null_entry) {
ip6_rt_put(rt);
rt = NULL;
}
return rt;
}
static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg)
{
struct net *net = cfg->fc_nlinfo.nl_net;
@ -1940,7 +1971,7 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg)
rt->rt6i_gateway = *gw_addr;
if (gwa_type != (IPV6_ADDR_LINKLOCAL|IPV6_ADDR_UNICAST)) {
struct rt6_info *grt;
struct rt6_info *grt = NULL;
/* IPv6 strictly inhibits using not link-local
addresses as nexthop address.
@ -1952,7 +1983,12 @@ static struct rt6_info *ip6_route_info_create(struct fib6_config *cfg)
if (!(gwa_type & IPV6_ADDR_UNICAST))
goto out;
grt = rt6_lookup(net, gw_addr, NULL, cfg->fc_ifindex, 1);
if (cfg->fc_table)
grt = ip6_nh_lookup_table(net, cfg, gw_addr);
if (!grt)
grt = rt6_lookup(net, gw_addr, NULL,
cfg->fc_ifindex, 1);
err = -EHOSTUNREACH;
if (!grt)