Skip to content

Commit

Permalink
Merge branch 'mpls-multipath-improvements'
Browse files Browse the repository at this point in the history 
Robert Shearman says:

====================
mpls: mulipath improvements

Two improvements to the recently added mpls multipath support. The
first is a fix for missing initialisation the nexthop address length
for the v4 and v6 explicit null label routes, and the second is to
reduce the amount of memory used by mpls routes by changing the way
the via addresses are stored.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
  • Loading branch information
David S. Miller committed Oct 28, 2015
2 parents c0f9c7e + cf4b24f commit 5b9e3bd
Show file tree
Hide file tree
Showing 2 changed files with 113 additions and 38 deletions.
123 changes: 88 additions & 35 deletions net/mpls/af_mpls.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -57,6 +57,20 @@ bool mpls_output_possible(const struct net_device *dev)
}
EXPORT_SYMBOL_GPL(mpls_output_possible);

static u8 *__mpls_nh_via(struct mpls_route *rt, struct mpls_nh *nh)
{
u8 *nh0_via = PTR_ALIGN((u8 *)&rt->rt_nh[rt->rt_nhn], VIA_ALEN_ALIGN);
int nh_index = nh - rt->rt_nh;

return nh0_via + rt->rt_max_alen * nh_index;
}

static const u8 *mpls_nh_via(const struct mpls_route *rt,
const struct mpls_nh *nh)
{
return __mpls_nh_via((struct mpls_route *)rt, (struct mpls_nh *)nh);
}

static unsigned int mpls_nh_header_size(const struct mpls_nh *nh)
{
/* The size of the layer 2.5 labels to be added for this route */
Expand Down Expand Up @@ -303,7 +317,7 @@ static int mpls_forward(struct sk_buff *skb, struct net_device *dev,
}
}

err = neigh_xmit(nh->nh_via_table, out_dev, nh->nh_via, skb);
err = neigh_xmit(nh->nh_via_table, out_dev, mpls_nh_via(rt, nh), skb);
if (err)
net_dbg_ratelimited("%s: packet transmission failed: %d\n",
__func__, err);
Expand Down Expand Up @@ -340,14 +354,19 @@ struct mpls_route_config {
int rc_mp_len;
};

static struct mpls_route *mpls_rt_alloc(int num_nh)
static struct mpls_route *mpls_rt_alloc(int num_nh, u8 max_alen)
{
u8 max_alen_aligned = ALIGN(max_alen, VIA_ALEN_ALIGN);
struct mpls_route *rt;

rt = kzalloc(sizeof(*rt) + (num_nh * sizeof(struct mpls_nh)),
rt = kzalloc(ALIGN(sizeof(*rt) + num_nh * sizeof(*rt->rt_nh),
VIA_ALEN_ALIGN) +
num_nh * max_alen_aligned,
GFP_KERNEL);
if (rt)
if (rt) {
rt->rt_nhn = num_nh;
rt->rt_max_alen = max_alen_aligned;
}

return rt;
}
Expand Down Expand Up @@ -408,7 +427,8 @@ static unsigned find_free_label(struct net *net)
}

#if IS_ENABLED(CONFIG_INET)
static struct net_device *inet_fib_lookup_dev(struct net *net, void *addr)
static struct net_device *inet_fib_lookup_dev(struct net *net,
const void *addr)
{
struct net_device *dev;
struct rtable *rt;
Expand All @@ -427,14 +447,16 @@ static struct net_device *inet_fib_lookup_dev(struct net *net, void *addr)
return dev;
}
#else
static struct net_device *inet_fib_lookup_dev(struct net *net, void *addr)
static struct net_device *inet_fib_lookup_dev(struct net *net,
const void *addr)
{
return ERR_PTR(-EAFNOSUPPORT);
}
#endif

#if IS_ENABLED(CONFIG_IPV6)
static struct net_device *inet6_fib_lookup_dev(struct net *net, void *addr)
static struct net_device *inet6_fib_lookup_dev(struct net *net,
const void *addr)
{
struct net_device *dev;
struct dst_entry *dst;
Expand All @@ -457,24 +479,26 @@ static struct net_device *inet6_fib_lookup_dev(struct net *net, void *addr)
return dev;
}
#else
static struct net_device *inet6_fib_lookup_dev(struct net *net, void *addr)
static struct net_device *inet6_fib_lookup_dev(struct net *net,
const void *addr)
{
return ERR_PTR(-EAFNOSUPPORT);
}
#endif

static struct net_device *find_outdev(struct net *net,
struct mpls_route *rt,
struct mpls_nh *nh, int oif)
{
struct net_device *dev = NULL;

if (!oif) {
switch (nh->nh_via_table) {
case NEIGH_ARP_TABLE:
dev = inet_fib_lookup_dev(net, nh->nh_via);
dev = inet_fib_lookup_dev(net, mpls_nh_via(rt, nh));
break;
case NEIGH_ND_TABLE:
dev = inet6_fib_lookup_dev(net, nh->nh_via);
dev = inet6_fib_lookup_dev(net, mpls_nh_via(rt, nh));
break;
case NEIGH_LINK_TABLE:
break;
Expand All @@ -492,12 +516,13 @@ static struct net_device *find_outdev(struct net *net,
return dev;
}

static int mpls_nh_assign_dev(struct net *net, struct mpls_nh *nh, int oif)
static int mpls_nh_assign_dev(struct net *net, struct mpls_route *rt,
struct mpls_nh *nh, int oif)
{
struct net_device *dev = NULL;
int err = -ENODEV;

dev = find_outdev(net, nh, oif);
dev = find_outdev(net, rt, nh, oif);
if (IS_ERR(dev)) {
err = PTR_ERR(dev);
dev = NULL;
Expand Down Expand Up @@ -538,10 +563,10 @@ static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
nh->nh_label[i] = cfg->rc_output_label[i];

nh->nh_via_table = cfg->rc_via_table;
memcpy(nh->nh_via, cfg->rc_via, cfg->rc_via_alen);
memcpy(__mpls_nh_via(rt, nh), cfg->rc_via, cfg->rc_via_alen);
nh->nh_via_alen = cfg->rc_via_alen;

err = mpls_nh_assign_dev(net, nh, cfg->rc_ifindex);
err = mpls_nh_assign_dev(net, rt, nh, cfg->rc_ifindex);
if (err)
goto errout;

Expand All @@ -551,8 +576,9 @@ static int mpls_nh_build_from_cfg(struct mpls_route_config *cfg,
return err;
}

static int mpls_nh_build(struct net *net, struct mpls_nh *nh,
int oif, struct nlattr *via, struct nlattr *newdst)
static int mpls_nh_build(struct net *net, struct mpls_route *rt,
struct mpls_nh *nh, int oif,
struct nlattr *via, struct nlattr *newdst)
{
int err = -ENOMEM;

Expand All @@ -567,11 +593,11 @@ static int mpls_nh_build(struct net *net, struct mpls_nh *nh,
}

err = nla_get_via(via, &nh->nh_via_alen, &nh->nh_via_table,
nh->nh_via);
__mpls_nh_via(rt, nh));
if (err)
goto errout;

err = mpls_nh_assign_dev(net, nh, oif);
err = mpls_nh_assign_dev(net, rt, nh, oif);
if (err)
goto errout;

Expand All @@ -581,12 +607,35 @@ static int mpls_nh_build(struct net *net, struct mpls_nh *nh,
return err;
}

static int mpls_count_nexthops(struct rtnexthop *rtnh, int len)
static int mpls_count_nexthops(struct rtnexthop *rtnh, int len,
u8 cfg_via_alen, u8 *max_via_alen)
{
int nhs = 0;
int remaining = len;

if (!rtnh) {
*max_via_alen = cfg_via_alen;
return 1;
}

*max_via_alen = 0;

while (rtnh_ok(rtnh, remaining)) {
struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
int attrlen;

attrlen = rtnh_attrlen(rtnh);
nla = nla_find(attrs, attrlen, RTA_VIA);
if (nla && nla_len(nla) >=
offsetof(struct rtvia, rtvia_addr)) {
int via_alen = nla_len(nla) -
offsetof(struct rtvia, rtvia_addr);

if (via_alen <= MAX_VIA_ALEN)
*max_via_alen = max_t(u16, *max_via_alen,
via_alen);
}

nhs++;
rtnh = rtnh_next(rtnh, &remaining);
}
Expand Down Expand Up @@ -631,7 +680,7 @@ static int mpls_nh_build_multi(struct mpls_route_config *cfg,
if (!nla_via)
goto errout;

err = mpls_nh_build(cfg->rc_nlinfo.nl_net, nh,
err = mpls_nh_build(cfg->rc_nlinfo.nl_net, rt, nh,
rtnh->rtnh_ifindex, nla_via,
nla_newdst);
if (err)
Expand All @@ -655,8 +704,9 @@ static int mpls_route_add(struct mpls_route_config *cfg)
struct net *net = cfg->rc_nlinfo.nl_net;
struct mpls_route *rt, *old;
int err = -EINVAL;
u8 max_via_alen;
unsigned index;
int nhs = 1; /* default to one nexthop */
int nhs;

index = cfg->rc_label;

Expand Down Expand Up @@ -693,15 +743,14 @@ static int mpls_route_add(struct mpls_route_config *cfg)
if (!(cfg->rc_nlflags & NLM_F_CREATE) && !old)
goto errout;

if (cfg->rc_mp) {
err = -EINVAL;
nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len);
if (nhs == 0)
goto errout;
}
err = -EINVAL;
nhs = mpls_count_nexthops(cfg->rc_mp, cfg->rc_mp_len,
cfg->rc_via_alen, &max_via_alen);
if (nhs == 0)
goto errout;

err = -ENOMEM;
rt = mpls_rt_alloc(nhs);
rt = mpls_rt_alloc(nhs, max_via_alen);
if (!rt)
goto errout;

Expand Down Expand Up @@ -1176,13 +1225,13 @@ static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
if (nla_put_labels(skb, RTA_DST, 1, &label))
goto nla_put_failure;
if (rt->rt_nhn == 1) {
struct mpls_nh *nh = rt->rt_nh;
const struct mpls_nh *nh = rt->rt_nh;

if (nh->nh_labels &&
nla_put_labels(skb, RTA_NEWDST, nh->nh_labels,
nh->nh_label))
goto nla_put_failure;
if (nla_put_via(skb, nh->nh_via_table, nh->nh_via,
if (nla_put_via(skb, nh->nh_via_table, mpls_nh_via(rt, nh),
nh->nh_via_alen))
goto nla_put_failure;
dev = rtnl_dereference(nh->nh_dev);
Expand All @@ -1209,7 +1258,7 @@ static int mpls_dump_route(struct sk_buff *skb, u32 portid, u32 seq, int event,
nh->nh_label))
goto nla_put_failure;
if (nla_put_via(skb, nh->nh_via_table,
nh->nh_via,
mpls_nh_via(rt, nh),
nh->nh_via_alen))
goto nla_put_failure;

Expand Down Expand Up @@ -1338,25 +1387,29 @@ static int resize_platform_label_table(struct net *net, size_t limit)
/* In case the predefined labels need to be populated */
if (limit > MPLS_LABEL_IPV4NULL) {
struct net_device *lo = net->loopback_dev;
rt0 = mpls_rt_alloc(1);
rt0 = mpls_rt_alloc(1, lo->addr_len);
if (!rt0)
goto nort0;
RCU_INIT_POINTER(rt0->rt_nh->nh_dev, lo);
rt0->rt_protocol = RTPROT_KERNEL;
rt0->rt_payload_type = MPT_IPV4;
rt0->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
memcpy(rt0->rt_nh->nh_via, lo->dev_addr, lo->addr_len);
rt0->rt_nh->nh_via_alen = lo->addr_len;
memcpy(__mpls_nh_via(rt0, rt0->rt_nh), lo->dev_addr,
lo->addr_len);
}
if (limit > MPLS_LABEL_IPV6NULL) {
struct net_device *lo = net->loopback_dev;
rt2 = mpls_rt_alloc(1);
rt2 = mpls_rt_alloc(1, lo->addr_len);
if (!rt2)
goto nort2;
RCU_INIT_POINTER(rt2->rt_nh->nh_dev, lo);
rt2->rt_protocol = RTPROT_KERNEL;
rt2->rt_payload_type = MPT_IPV6;
rt2->rt_nh->nh_via_table = NEIGH_LINK_TABLE;
memcpy(rt2->rt_nh->nh_via, lo->dev_addr, lo->addr_len);
rt2->rt_nh->nh_via_alen = lo->addr_len;
memcpy(__mpls_nh_via(rt2, rt2->rt_nh), lo->dev_addr,
lo->addr_len);
}

rtnl_lock();
Expand Down
28 changes: 25 additions & 3 deletions net/mpls/internal.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,8 @@ struct sk_buff;
#define MAX_NEW_LABELS 2

/* This maximum ha length copied from the definition of struct neighbour */
#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, sizeof(unsigned long)))
#define VIA_ALEN_ALIGN sizeof(unsigned long)
#define MAX_VIA_ALEN (ALIGN(MAX_ADDR_LEN, VIA_ALEN_ALIGN))

enum mpls_payload_type {
MPT_UNSPEC, /* IPv4 or IPv6 */
Expand All @@ -44,14 +45,35 @@ struct mpls_nh { /* next hop label forwarding entry */
u8 nh_labels;
u8 nh_via_alen;
u8 nh_via_table;
u8 nh_via[MAX_VIA_ALEN];
};

/* The route, nexthops and vias are stored together in the same memory
* block:
*
* +----------------------+
* | mpls_route |
* +----------------------+
* | mpls_nh 0 |
* +----------------------+
* | ... |
* +----------------------+
* | mpls_nh n-1 |
* +----------------------+
* | alignment padding |
* +----------------------+
* | via[rt_max_alen] 0 |
* +----------------------+
* | ... |
* +----------------------+
* | via[rt_max_alen] n-1 |
* +----------------------+
*/
struct mpls_route { /* next hop label forwarding entry */
struct rcu_head rt_rcu;
u8 rt_protocol;
u8 rt_payload_type;
int rt_nhn;
u8 rt_max_alen;
unsigned int rt_nhn;
struct mpls_nh rt_nh[0];
};

Expand Down

0 comments on commit 5b9e3bd

Please sign in to comment.