Number of nexthops and number of alive nexthops are tracked using an
unsigned int. A route should never have more than 255 nexthops so
convert both to u8. Update all references and intermediate variables
to consistently use u8 as well.
Shrinks the size of mpls_route from 32 bytes to 24 bytes with a 2-byte
hole before the nexthops.
Signed-off-by: David Ahern <d...@cumulusnetworks.com>
---
v2
- label u16 hole in mpls_route as rt_reserved1
net/mpls/af_mpls.c | 28 +++++++++++++++++-----------
net/mpls/internal.h | 5 +++--
2 files changed, 20 insertions(+), 13 deletions(-)
diff --git a/net/mpls/af_mpls.c b/net/mpls/af_mpls.c
index 6bdd2f95b576..665dec84f001 100644
--- a/net/mpls/af_mpls.c
+++ b/net/mpls/af_mpls.c
@@ -197,10 +197,10 @@ static u32 mpls_multipath_hash(struct mpls_route *rt,
struct sk_buff *skb)
static struct mpls_nh *mpls_select_multipath(struct mpls_route *rt,
struct sk_buff *skb)
{
- unsigned int alive;
u32 hash = 0;
int nh_index = 0;
int n = 0;
+ u8 alive;
/* No need to look further into packet if there's only
* one path
@@ -466,7 +466,7 @@ struct mpls_route_config {
int rc_mp_len;
};
-static struct mpls_route *mpls_rt_alloc(int num_nh, u8 max_alen)
+static struct mpls_route *mpls_rt_alloc(u8 num_nh, u8 max_alen)
{
u8 max_alen_aligned = ALIGN(max_alen, VIA_ALEN_ALIGN);
struct mpls_route *rt;
@@ -744,11 +744,11 @@ static int mpls_nh_build(struct net *net, struct
mpls_route *rt,
return err;
}
-static int mpls_count_nexthops(struct rtnexthop *rtnh, int len,
- u8 cfg_via_alen, u8 *max_via_alen)
+static u8 mpls_count_nexthops(struct rtnexthop *rtnh, int len,
+ u8 cfg_via_alen, u8 *max_via_alen)
{
- int nhs = 0;
int remaining = len;
+ u8 nhs = 0;
if (!rtnh) {
*max_via_alen = cfg_via_alen;
@@ -773,7 +773,13 @@ static int mpls_count_nexthops(struct rtnexthop *rtnh, int
len,
via_alen);
}
+ /* number of nexthops is tracked by a u8.
+ * Check for overflow.
+ */
+ if (nhs == 255)
+ return 0;
nhs++;
+
rtnh = rtnh_next(rtnh, &remaining);
}
@@ -787,8 +793,8 @@ static int mpls_nh_build_multi(struct mpls_route_config
*cfg,
struct rtnexthop *rtnh = cfg->rc_mp;
struct nlattr *nla_via, *nla_newdst;
int remaining = cfg->rc_mp_len;
- int nhs = 0;
int err = 0;
+ u8 nhs = 0;
change_nexthops(rt) {
int attrlen;
@@ -842,7 +848,7 @@ static int mpls_route_add(struct mpls_route_config *cfg)
int err = -EINVAL;
u8 max_via_alen;
unsigned index;
- int nhs;
+ u8 nhs;
index = cfg->rc_label;
@@ -1310,7 +1316,7 @@ static void mpls_ifdown(struct net_device *dev, int event)
{
struct mpls_route __rcu **platform_label;
struct net *net = dev_net(dev);
- unsigned int alive, deleted;
+ u8 alive, deleted;
unsigned index;
platform_label = rtnl_dereference(net->mpls.platform_label);
@@ -1362,7 +1368,7 @@ static void mpls_ifup(struct net_device *dev, unsigned
int flags)
struct mpls_route __rcu **platform_label;
struct net *net = dev_net(dev);
unsigned index;
- int alive;
+ u8 alive;
platform_label = rtnl_dereference(net->mpls.platform_label);
for (index = 0; index < net->mpls.platform_labels; index++) {
@@ -1786,8 +1792,8 @@ static int mpls_dump_route(struct sk_buff *skb, u32
portid, u32 seq, int event,
} else {
struct rtnexthop *rtnh;
struct nlattr *mp;
- int dead = 0;
- int linkdown = 0;
+ u8 linkdown = 0;
+ u8 dead = 0;
mp = nla_nest_start(skb, RTA_MULTIPATH);
if (!mp)
diff --git a/net/mpls/internal.h b/net/mpls/internal.h
index 91419fe63464..2ac97433c3b7 100644
--- a/net/mpls/internal.h
+++ b/net/mpls/internal.h
@@ -127,12 +127,13 @@ struct mpls_route { /* next hop label forwarding entry */
u8 rt_payload_type;
u8 rt_max_alen;
u8 rt_ttl_propagate;
- unsigned int rt_nhn;
+ u8 rt_nhn;
/* rt_nhn_alive is accessed under RCU in the packet path; it
* is modified handling netdev events with rtnl lock held
*/
- unsigned int rt_nhn_alive;
+ u8 rt_nhn_alive;
+ u16 rt_reserved1;
struct mpls_nh rt_nh[0];
};
--
2.1.4
