linux/net/mpls/internal.h
Roopa Prabhu c89359a42e mpls: support for dead routes
Adds support for RTNH_F_DEAD and RTNH_F_LINKDOWN flags on mpls
routes due to link events. Also adds code to ignore dead
routes during route selection.

Unlike ip routes, mpls routes are not deleted when the route goes
dead. This is current mpls behaviour and this patch does not change
that. With this patch however, routes will be marked dead.
dead routes are not notified to userspace (this is consistent with ipv4
routes).

dead routes:
-----------
$ip -f mpls route show
100
    nexthop as to 200 via inet 10.1.1.2  dev swp1
    nexthop as to 700 via inet 10.1.1.6  dev swp2

$ip link set dev swp1 down

$ip link show dev swp1
4: swp1: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN mode
DEFAULT group default qlen 1000
    link/ether 00:02:00:00:00:01 brd ff:ff:ff:ff:ff:ff

$ip -f mpls route show
100
    nexthop as to 200 via inet 10.1.1.2  dev swp1 dead linkdown
    nexthop as to 700 via inet 10.1.1.6  dev swp2

linkdown routes:
----------------
$ip -f mpls route show
100
    nexthop as to 200 via inet 10.1.1.2  dev swp1
    nexthop as to 700 via inet 10.1.1.6  dev swp2

$ip link show dev swp1
4: swp1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
state UP mode DEFAULT group default qlen 1000
    link/ether 00:02:00:00:00:01 brd ff:ff:ff:ff:ff:ff

/* carrier goes down */
$ip link show dev swp1
4: swp1: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast
state DOWN mode DEFAULT group default qlen 1000
    link/ether 00:02:00:00:00:01 brd ff:ff:ff:ff:ff:ff

$ip -f mpls route show
100
    nexthop as to 200 via inet 10.1.1.2  dev swp1 linkdown
    nexthop as to 700 via inet 10.1.1.6  dev swp2

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Acked-by: Robert Shearman <rshearma@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-03 15:03:27 -05:00

136 lines
3.5 KiB
C

#ifndef MPLS_INTERNAL_H
#define MPLS_INTERNAL_H
struct mpls_shim_hdr {
__be32 label_stack_entry;
};
struct mpls_entry_decoded {
u32 label;
u8 ttl;
u8 tc;
u8 bos;
};
struct mpls_dev {
int input_enabled;
struct ctl_table_header *sysctl;
struct rcu_head rcu;
};
struct sk_buff;
#define LABEL_NOT_SPECIFIED (1 << 20)
#define MAX_NEW_LABELS 2
/* This maximum ha length copied from the definition of struct neighbour */
#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 */
MPT_IPV4 = 4,
MPT_IPV6 = 6,
/* Other types not implemented:
* - Pseudo-wire with or without control word (RFC4385)
* - GAL (RFC5586)
*/
};
struct mpls_nh { /* next hop label forwarding entry */
struct net_device __rcu *nh_dev;
unsigned int nh_flags;
u32 nh_label[MAX_NEW_LABELS];
u8 nh_labels;
u8 nh_via_alen;
u8 nh_via_table;
};
/* 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;
u8 rt_max_alen;
unsigned int rt_nhn;
unsigned int rt_nhn_alive;
struct mpls_nh rt_nh[0];
};
#define for_nexthops(rt) { \
int nhsel; struct mpls_nh *nh; \
for (nhsel = 0, nh = (rt)->rt_nh; \
nhsel < (rt)->rt_nhn; \
nh++, nhsel++)
#define change_nexthops(rt) { \
int nhsel; struct mpls_nh *nh; \
for (nhsel = 0, nh = (struct mpls_nh *)((rt)->rt_nh); \
nhsel < (rt)->rt_nhn; \
nh++, nhsel++)
#define endfor_nexthops(rt) }
static inline struct mpls_shim_hdr *mpls_hdr(const struct sk_buff *skb)
{
return (struct mpls_shim_hdr *)skb_network_header(skb);
}
static inline struct mpls_shim_hdr mpls_entry_encode(u32 label, unsigned ttl, unsigned tc, bool bos)
{
struct mpls_shim_hdr result;
result.label_stack_entry =
cpu_to_be32((label << MPLS_LS_LABEL_SHIFT) |
(tc << MPLS_LS_TC_SHIFT) |
(bos ? (1 << MPLS_LS_S_SHIFT) : 0) |
(ttl << MPLS_LS_TTL_SHIFT));
return result;
}
static inline struct mpls_entry_decoded mpls_entry_decode(struct mpls_shim_hdr *hdr)
{
struct mpls_entry_decoded result;
unsigned entry = be32_to_cpu(hdr->label_stack_entry);
result.label = (entry & MPLS_LS_LABEL_MASK) >> MPLS_LS_LABEL_SHIFT;
result.ttl = (entry & MPLS_LS_TTL_MASK) >> MPLS_LS_TTL_SHIFT;
result.tc = (entry & MPLS_LS_TC_MASK) >> MPLS_LS_TC_SHIFT;
result.bos = (entry & MPLS_LS_S_MASK) >> MPLS_LS_S_SHIFT;
return result;
}
int nla_put_labels(struct sk_buff *skb, int attrtype, u8 labels,
const u32 label[]);
int nla_get_labels(const struct nlattr *nla, u32 max_labels, u8 *labels,
u32 label[]);
int nla_get_via(const struct nlattr *nla, u8 *via_alen, u8 *via_table,
u8 via[]);
bool mpls_output_possible(const struct net_device *dev);
unsigned int mpls_dev_mtu(const struct net_device *dev);
bool mpls_pkt_too_big(const struct sk_buff *skb, unsigned int mtu);
#endif /* MPLS_INTERNAL_H */