ipv6: Rename fib6_multipath_select and pass fib6_result

Add 'struct fib6_result' to hold the fib entry and fib6_nh from a fib
lookup as separate entries, similar to what IPv4 now has with fib_result.

Rename fib6_multipath_select to fib6_select_path, pass fib6_result to
it, and set f6i and nh in the result once a path selection is done.
Call fib6_select_path unconditionally for path selection which means
moving the sibling and oif check to fib6_select_path. To handle the two
different call paths (2 only call multipath_select if flowi6_oif == 0 and
the other always calls it), add a new have_oif_match that controls the
sibling walk if relevant.

Update callers of fib6_multipath_select accordingly and have them use the
fib6_info and fib6_nh from the result.

This is needed for multipath nexthop objects where a single f6i can
point to multiple fib6_nh (similar to IPv4).

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David Ahern 2019-04-16 14:35:59 -07:00 committed by David S. Miller
parent 6b0a7f84ea
commit b1d4099150
6 changed files with 68 additions and 64 deletions

View File

@ -190,6 +190,11 @@ struct rt6_info {
unsigned short rt6i_nfheader_len;
};
struct fib6_result {
struct fib6_nh *nh;
struct fib6_info *f6i;
};
#define for_each_fib6_node_rt_rcu(fn) \
for (rt = rcu_dereference((fn)->leaf); rt; \
rt = rcu_dereference(rt->fib6_next))
@ -391,11 +396,9 @@ struct fib6_info *fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
struct fib6_info *fib6_table_lookup(struct net *net, struct fib6_table *table,
int oif, struct flowi6 *fl6, int strict);
struct fib6_info *fib6_multipath_select(const struct net *net,
struct fib6_info *match,
struct flowi6 *fl6, int oif,
const struct sk_buff *skb, int strict);
void fib6_select_path(const struct net *net, struct fib6_result *res,
struct flowi6 *fl6, int oif, bool have_oif_match,
const struct sk_buff *skb, int strict);
struct fib6_node *fib6_node_lookup(struct fib6_node *root,
const struct in6_addr *daddr,
const struct in6_addr *saddr);

View File

@ -14,6 +14,7 @@
struct fib6_info;
struct fib6_nh;
struct fib6_config;
struct fib6_result;
/* This is ugly, ideally these symbols should be built
* into the core kernel.
@ -34,11 +35,9 @@ struct ipv6_stub {
struct fib6_table *table,
int oif, struct flowi6 *fl6,
int flags);
struct fib6_info *(*fib6_multipath_select)(const struct net *net,
struct fib6_info *f6i,
struct flowi6 *fl6, int oif,
const struct sk_buff *skb,
int strict);
void (*fib6_select_path)(const struct net *net, struct fib6_result *res,
struct flowi6 *fl6, int oif, bool oif_match,
const struct sk_buff *skb, int strict);
u32 (*ip6_mtu_from_fib6)(struct fib6_info *f6i, struct in6_addr *daddr,
struct in6_addr *saddr);

View File

@ -4679,9 +4679,9 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
struct in6_addr *src = (struct in6_addr *) params->ipv6_src;
struct in6_addr *dst = (struct in6_addr *) params->ipv6_dst;
struct neighbour *neigh;
struct fib6_result res;
struct net_device *dev;
struct inet6_dev *idev;
struct fib6_info *f6i;
struct flowi6 fl6;
int strict = 0;
int oif;
@ -4726,21 +4726,23 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
if (unlikely(!tb))
return BPF_FIB_LKUP_RET_NOT_FWDED;
f6i = ipv6_stub->fib6_table_lookup(net, tb, oif, &fl6, strict);
res.f6i = ipv6_stub->fib6_table_lookup(net, tb, oif, &fl6,
strict);
} else {
fl6.flowi6_mark = 0;
fl6.flowi6_secid = 0;
fl6.flowi6_tun_key.tun_id = 0;
fl6.flowi6_uid = sock_net_uid(net, NULL);
f6i = ipv6_stub->fib6_lookup(net, oif, &fl6, strict);
res.f6i = ipv6_stub->fib6_lookup(net, oif, &fl6, strict);
}
if (unlikely(IS_ERR_OR_NULL(f6i) || f6i == net->ipv6.fib6_null_entry))
if (unlikely(IS_ERR_OR_NULL(res.f6i) ||
res.f6i == net->ipv6.fib6_null_entry))
return BPF_FIB_LKUP_RET_NOT_FWDED;
if (unlikely(f6i->fib6_flags & RTF_REJECT)) {
switch (f6i->fib6_type) {
if (unlikely(res.f6i->fib6_flags & RTF_REJECT)) {
switch (res.f6i->fib6_type) {
case RTN_BLACKHOLE:
return BPF_FIB_LKUP_RET_BLACKHOLE;
case RTN_UNREACHABLE:
@ -4752,28 +4754,26 @@ static int bpf_ipv6_fib_lookup(struct net *net, struct bpf_fib_lookup *params,
}
}
if (f6i->fib6_type != RTN_UNICAST)
if (res.f6i->fib6_type != RTN_UNICAST)
return BPF_FIB_LKUP_RET_NOT_FWDED;
if (f6i->fib6_nsiblings && fl6.flowi6_oif == 0)
f6i = ipv6_stub->fib6_multipath_select(net, f6i, &fl6,
fl6.flowi6_oif, NULL,
strict);
ipv6_stub->fib6_select_path(net, &res, &fl6, fl6.flowi6_oif,
fl6.flowi6_oif != 0, NULL, strict);
if (check_mtu) {
mtu = ipv6_stub->ip6_mtu_from_fib6(f6i, dst, src);
mtu = ipv6_stub->ip6_mtu_from_fib6(res.f6i, dst, src);
if (params->tot_len > mtu)
return BPF_FIB_LKUP_RET_FRAG_NEEDED;
}
if (f6i->fib6_nh.fib_nh_lws)
if (res.nh->fib_nh_lws)
return BPF_FIB_LKUP_RET_UNSUPP_LWT;
if (f6i->fib6_nh.fib_nh_gw_family)
*dst = f6i->fib6_nh.fib_nh_gw6;
if (res.nh->fib_nh_gw_family)
*dst = res.nh->fib_nh_gw6;
dev = f6i->fib6_nh.fib_nh_dev;
params->rt_metric = f6i->fib6_metric;
dev = res.nh->fib_nh_dev;
params->rt_metric = res.f6i->fib6_metric;
/* xdp and cls_bpf programs are run in RCU-bh so rcu_read_lock_bh is
* not needed here.

View File

@ -158,12 +158,11 @@ eafnosupport_fib6_lookup(struct net *net, int oif, struct flowi6 *fl6,
return NULL;
}
static struct fib6_info *
eafnosupport_fib6_multipath_select(const struct net *net, struct fib6_info *f6i,
struct flowi6 *fl6, int oif,
const struct sk_buff *skb, int strict)
static void
eafnosupport_fib6_select_path(const struct net *net, struct fib6_result *res,
struct flowi6 *fl6, int oif, bool have_oif_match,
const struct sk_buff *skb, int strict)
{
return f6i;
}
static u32
@ -187,7 +186,7 @@ const struct ipv6_stub *ipv6_stub __read_mostly = &(struct ipv6_stub) {
.fib6_get_table = eafnosupport_fib6_get_table,
.fib6_table_lookup = eafnosupport_fib6_table_lookup,
.fib6_lookup = eafnosupport_fib6_lookup,
.fib6_multipath_select = eafnosupport_fib6_multipath_select,
.fib6_select_path = eafnosupport_fib6_select_path,
.ip6_mtu_from_fib6 = eafnosupport_ip6_mtu_from_fib6,
.fib6_nh_init = eafnosupport_fib6_nh_init,
};

View File

@ -917,7 +917,7 @@ static const struct ipv6_stub ipv6_stub_impl = {
.fib6_get_table = fib6_get_table,
.fib6_table_lookup = fib6_table_lookup,
.fib6_lookup = fib6_lookup,
.fib6_multipath_select = fib6_multipath_select,
.fib6_select_path = fib6_select_path,
.ip6_mtu_from_fib6 = ip6_mtu_from_fib6,
.fib6_nh_init = fib6_nh_init,
.fib6_nh_release = fib6_nh_release,

View File

@ -428,13 +428,15 @@ static bool rt6_check_expired(const struct rt6_info *rt)
return false;
}
struct fib6_info *fib6_multipath_select(const struct net *net,
struct fib6_info *match,
struct flowi6 *fl6, int oif,
const struct sk_buff *skb,
int strict)
void fib6_select_path(const struct net *net, struct fib6_result *res,
struct flowi6 *fl6, int oif, bool have_oif_match,
const struct sk_buff *skb, int strict)
{
struct fib6_info *sibling, *next_sibling;
struct fib6_info *match = res->f6i;
if (!match->fib6_nsiblings || have_oif_match)
goto out;
/* We might have already computed the hash for ICMPv6 errors. In such
* case it will always be non-zero. Otherwise now is the time to do it.
@ -443,7 +445,7 @@ struct fib6_info *fib6_multipath_select(const struct net *net,
fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
if (fl6->mp_hash <= atomic_read(&match->fib6_nh.fib_nh_upper_bound))
return match;
goto out;
list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
fib6_siblings) {
@ -459,7 +461,9 @@ struct fib6_info *fib6_multipath_select(const struct net *net,
break;
}
return match;
out:
res->f6i = match;
res->nh = &match->fib6_nh;
}
/*
@ -1063,7 +1067,7 @@ static struct rt6_info *ip6_pol_route_lookup(struct net *net,
const struct sk_buff *skb,
int flags)
{
struct fib6_info *f6i;
struct fib6_result res = {};
struct fib6_node *fn;
struct rt6_info *rt;
@ -1073,14 +1077,14 @@ static struct rt6_info *ip6_pol_route_lookup(struct net *net,
rcu_read_lock();
fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
restart:
f6i = rcu_dereference(fn->leaf);
if (!f6i)
f6i = net->ipv6.fib6_null_entry;
res.f6i = rcu_dereference(fn->leaf);
if (!res.f6i)
res.f6i = net->ipv6.fib6_null_entry;
else
f6i = rt6_device_match(net, f6i, &fl6->saddr,
fl6->flowi6_oif, flags);
res.f6i = rt6_device_match(net, res.f6i, &fl6->saddr,
fl6->flowi6_oif, flags);
if (f6i == net->ipv6.fib6_null_entry) {
if (res.f6i == net->ipv6.fib6_null_entry) {
fn = fib6_backtrack(fn, &fl6->saddr);
if (fn)
goto restart;
@ -1090,20 +1094,20 @@ restart:
goto out;
}
if (f6i->fib6_nsiblings && fl6->flowi6_oif == 0)
f6i = fib6_multipath_select(net, f6i, fl6, fl6->flowi6_oif, skb,
flags);
fib6_select_path(net, &res, fl6, fl6->flowi6_oif,
fl6->flowi6_oif != 0, skb, flags);
/* Search through exception table */
rt = rt6_find_cached_rt(f6i, &fl6->daddr, &fl6->saddr);
rt = rt6_find_cached_rt(res.f6i, &fl6->daddr, &fl6->saddr);
if (rt) {
if (ip6_hold_safe(net, &rt))
dst_use_noref(&rt->dst, jiffies);
} else {
rt = ip6_create_rt_rcu(f6i);
rt = ip6_create_rt_rcu(res.f6i);
}
out:
trace_fib6_table_lookup(net, f6i, table, fl6);
trace_fib6_table_lookup(net, res.f6i, table, fl6);
rcu_read_unlock();
@ -1843,7 +1847,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
int oif, struct flowi6 *fl6,
const struct sk_buff *skb, int flags)
{
struct fib6_info *f6i;
struct fib6_result res = {};
struct rt6_info *rt;
int strict = 0;
@ -1854,19 +1858,18 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
rcu_read_lock();
f6i = fib6_table_lookup(net, table, oif, fl6, strict);
if (f6i == net->ipv6.fib6_null_entry) {
res.f6i = fib6_table_lookup(net, table, oif, fl6, strict);
if (res.f6i == net->ipv6.fib6_null_entry) {
rt = net->ipv6.ip6_null_entry;
rcu_read_unlock();
dst_hold(&rt->dst);
return rt;
}
if (f6i->fib6_nsiblings)
f6i = fib6_multipath_select(net, f6i, fl6, oif, skb, strict);
fib6_select_path(net, &res, fl6, oif, false, skb, strict);
/*Search through exception table */
rt = rt6_find_cached_rt(f6i, &fl6->daddr, &fl6->saddr);
rt = rt6_find_cached_rt(res.f6i, &fl6->daddr, &fl6->saddr);
if (rt) {
if (ip6_hold_safe(net, &rt))
dst_use_noref(&rt->dst, jiffies);
@ -1874,7 +1877,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
rcu_read_unlock();
return rt;
} else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
!f6i->fib6_nh.fib_nh_gw_family)) {
!res.nh->fib_nh_gw_family)) {
/* Create a RTF_CACHE clone which will not be
* owned by the fib6 tree. It is for the special case where
* the daddr in the skb during the neighbor look-up is different
@ -1882,7 +1885,7 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
*/
struct rt6_info *uncached_rt;
uncached_rt = ip6_rt_cache_alloc(f6i, &fl6->daddr, NULL);
uncached_rt = ip6_rt_cache_alloc(res.f6i, &fl6->daddr, NULL);
rcu_read_unlock();
@ -1904,10 +1907,10 @@ struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
struct rt6_info *pcpu_rt;
local_bh_disable();
pcpu_rt = rt6_get_pcpu_route(f6i);
pcpu_rt = rt6_get_pcpu_route(res.f6i);
if (!pcpu_rt)
pcpu_rt = rt6_make_pcpu_route(net, f6i);
pcpu_rt = rt6_make_pcpu_route(net, res.f6i);
local_bh_enable();
rcu_read_unlock();