mirrors/bird
mirrors/bird
0
0
Fork 0
mirror of https://gitlab.nic.cz/labs/bird.git synced 2024-12-22 17:51:53 +00:00
Code Releases Activity

Netlink: MPLS routes in kernel, not fully working yet.

Browse Source 
TODO:
- fix static to detect MPLS stack changes on reload
- fix MPLS_ENCAP parsing on route scan

Anyway, Bird is now capable to insert both MPLS routes and MPLS encap
routes into kernel.

It was (among others) needed to define platform-specific AF_MPLS to 28
as this constant has been assigned in the linux kernel.

No support for BSD now, it may be added in the future.
This commit is contained in:
Jan Moskyto Matejka 2016-03-04 12:55:50 +01:00
parent 21d358f074
commit 45f01fb32e
5 changed files with 246 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

43
lib/mpls.h
View File

@ -11,10 +11,53 @@
#define _BIRD_MPLS_H_
#define MPLS_STACK_LENGTH 8 /* Adjust this if you need deeper MPLS stack */
#define MPLS_PXLEN 20 /* Length of the label in bits. Constant. */
/*
* RFC 3032 updated by RFC 5462:
*
* 0 1 2 3
* 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Label
* | Label | TC |S| TTL | Stack
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Entry
*
* Label: Label Value, 20 bits
* TC: Traffic Class, 3 bits
* S: Bottom of Stack, 1 bit
* TTL: Time to Live, 8 bits
*/
typedef struct mpls_stack {
u8 len;
u32 label[MPLS_STACK_LENGTH];
} mpls_stack;
static inline char * const mpls_hton(mpls_stack s) {
static char buf[MPLS_STACK_LENGTH*4];
int i;
for (i = 0; i < s.len; i++) {
buf[i*4 + 0] = s.label[i] >> 12;
buf[i*4 + 1] = s.label[i] >> 4;
buf[i*4 + 2] = (s.label[i] << 4) | (i == s.len - 1 ? 0x1 : 0);
buf[i*4 + 3] = 0;
}
return buf;
}
static inline int mpls_buflen(const char *buf) {
// Looking for the Bottom of Stack set to 4.
int i;
for (i = 0; !(buf[i++*4 + 2] & 0x1); );
return i*4;
}
static inline mpls_stack mpls_ntoh(const char *buf) {
mpls_stack s = { .len = mpls_buflen(buf) };
int i;
for (i = 0; i < s.len; i++)
s.label[i] = (buf[i*4 + 0] << 12) | (buf[i*4 + 1] << 4) | (buf[i*4 + 2] >> 4);
return s;
}
#endif

15
lib/net.h
View File

@ -11,6 +11,7 @@
#define _BIRD_NET_H_
#include "lib/ip.h"
#include "lib/mpls.h"
#define NET_IP4 1
@ -134,7 +135,7 @@ extern const u16 net_max_text_length[];
((net_addr_roa6) { NET_ROA6, pxlen, sizeof(net_addr_roa6), prefix, max_pxlen, asn })
#define NET_ADDR_MPLS(label) \
((net_addr_mpls) { NET_MPLS, 0, sizeof(net_addr_mpls), label })
((net_addr_mpls) { NET_MPLS, MPLS_PXLEN, sizeof(net_addr_mpls), label })
static inline void net_fill_ip4(net_addr *a, ip4_addr prefix, uint pxlen)
@ -211,6 +212,18 @@ static inline ip_addr net_prefix(const net_addr *a)
}
}
static inline mpls_stack net_mpls(const net_addr *a)
{
mpls_stack ms;
if (a->type == NET_MPLS) {
ms.len = 1;
ms.label[0] = ((net_addr_mpls *) a)->label;
return ms;
}
bug("Can't call net_mpls on non-mpls net_addr");
}
static inline uint net4_pxlen(const net_addr *a)
{ return a->pxlen; }

4
sysdep/cf/linux.h
View File

@ -16,6 +16,10 @@
#define CONFIG_RESTRICTED_PRIVILEGES
#ifndef AF_MPLS
#define AF_MPLS 28
#endif
/*
Link: sysdep/linux
Link: sysdep/unix

197
sysdep/linux/netlink.c
View File

@ -26,10 +26,12 @@
#include "lib/socket.h"
#include "lib/string.h"
#include "lib/hash.h"
#include "lib/mpls.h"
#include "conf/conf.h"
#include <asm/types.h>
#include <linux/if.h>
#include <linux/lwtunnel.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
@ -46,6 +48,25 @@
#define RTA_TABLE 15
#endif
#ifndef RTA_VIA
#define RTA_VIA 18
#endif
#ifndef RTA_NEWDST
#define RTA_NEWDST 19
#endif
#ifndef RTA_ENCAP_TYPE
#define RTA_ENCAP_TYPE 21
#endif
#ifndef RTA_ENCAP
#define RTA_ENCAP 22
#endif
#ifndef AF_MPLS
#define AF_MPLS 28
#endif
/*
* Synchronous Netlink interface
@ -256,7 +277,7 @@ static struct nl_want_attrs ifa_attr_want6[BIRD_IFA_MAX] = {
};
#define BIRD_RTA_MAX (RTA_TABLE+1)
#define BIRD_RTA_MAX (RTA_ENCAP+1)
static struct nl_want_attrs mpnh_attr_want4[BIRD_RTA_MAX] = {
[RTA_GATEWAY] = { 1, 1, sizeof(ip4_addr) },
@ -272,6 +293,8 @@ static struct nl_want_attrs rtm_attr_want4[BIRD_RTA_MAX] = {
[RTA_MULTIPATH] = { 1, 0, 0 },
[RTA_FLOW] = { 1, 1, sizeof(u32) },
[RTA_TABLE] = { 1, 1, sizeof(u32) },
[RTA_ENCAP_TYPE]= { 1, 1, sizeof(u16) },
[RTA_ENCAP] = { 1, 0, 0 },
};
static struct nl_want_attrs rtm_attr_want6[BIRD_RTA_MAX] = {
@ -284,6 +307,20 @@ static struct nl_want_attrs rtm_attr_want6[BIRD_RTA_MAX] = {
[RTA_METRICS] = { 1, 0, 0 },
[RTA_FLOW] = { 1, 1, sizeof(u32) },
[RTA_TABLE] = { 1, 1, sizeof(u32) },
[RTA_ENCAP_TYPE]= { 1, 1, sizeof(u16) },
[RTA_ENCAP] = { 1, 0, 0 },
};
static struct nl_want_attrs rtm_attr_want_mpls[BIRD_RTA_MAX] = {
[RTA_DST] = { 1, 1, sizeof(u32) },
[RTA_IIF] = { 1, 1, sizeof(u32) },
[RTA_OIF] = { 1, 1, sizeof(u32) },
[RTA_PRIORITY] = { 1, 1, sizeof(u32) },
[RTA_METRICS] = { 1, 0, 0 },
[RTA_FLOW] = { 1, 1, sizeof(u32) },
[RTA_TABLE] = { 1, 1, sizeof(u32) },
[RTA_VIA] = { 1, 0, 0 },
[RTA_NEWDST] = { 1, 0, 0 },
};
@ -333,6 +370,30 @@ static inline ip_addr rta_get_ipa(struct rtattr *a)
return ipa_from_ip6(rta_get_ip6(a));
}
static inline ip_addr rta_get_via(struct rtattr *a)
{
struct rtvia *v = RTA_DATA(a);
switch(v->rtvia_family) {
case AF_INET: return ipa_from_ip4(ip4_ntoh(*(ip4_addr *) v->rtvia_addr));
case AF_INET6: return ipa_from_ip6(ip6_ntoh(*(ip6_addr *) v->rtvia_addr));
}
return IPA_NONE;
}
static inline mpls_stack rta_get_mpls(struct rtattr *a)
{
mpls_stack ms = { .len = RTA_PAYLOAD(a) / 4 };
for (int i = 0; i < ms.len; i++) {
ms.label[i] = (((u8 *)RTA_DATA(a))[i*4 + 0] << 12)
| (((u8 *)RTA_DATA(a))[i*4 + 1] << 4)
| (((u8 *)RTA_DATA(a))[i*4 + 2] >> 4);
if (!!(((u8 *)RTA_DATA(a))[i*4 + 2] & 1) != (i+1 == ms.len))
log(L_WARN "KRT: Received a route with mismatched MPLS BoS bit, ignoring");
}
return ms;
}
struct rtattr *
nl_add_attr(struct nlmsghdr *h, uint bufsize, uint code, const void *data, uint dlen)
{
@ -353,6 +414,24 @@ nl_add_attr(struct nlmsghdr *h, uint bufsize, uint code, const void *data, uint
return a;
}
static inline struct rtattr *
nl_open_attr(struct nlmsghdr *h, uint bufsize, uint code)
{
return nl_add_attr(h, bufsize, code, NULL, 0);
}
static inline void
nl_close_attr(struct nlmsghdr *h, struct rtattr *a)
{
a->rta_len = (void *)h + h->nlmsg_len - (void *)a;
}
static inline void
nl_add_attr_u16(struct nlmsghdr *h, uint bufsize, int code, u16 data)
{
nl_add_attr(h, bufsize, code, &data, 2);
}
static inline void
nl_add_attr_u32(struct nlmsghdr *h, uint bufsize, int code, u32 data)
{
@ -382,16 +461,46 @@ nl_add_attr_ipa(struct nlmsghdr *h, uint bufsize, int code, ip_addr ipa)
nl_add_attr_ip6(h, bufsize, code, ipa_to_ip6(ipa));
}
static inline struct rtattr *
nl_open_attr(struct nlmsghdr *h, uint bufsize, uint code)
static inline void
nl_add_attr_mpls(struct nlmsghdr *h, uint bufsize, int code, mpls_stack ms)
{
return nl_add_attr(h, bufsize, code, NULL, 0);
const char *buf = mpls_hton(ms);
nl_add_attr(h, bufsize, code, buf, mpls_buflen(buf));
}
static inline void
nl_close_attr(struct nlmsghdr *h, struct rtattr *a)
nl_add_attr_mpls_encap(struct nlmsghdr *h, uint bufsize, mpls_stack ms)
{
a->rta_len = (void *)h + NLMSG_ALIGN(h->nlmsg_len) - (void *)a;
struct rtattr *nest = nl_open_attr(h, bufsize, RTA_ENCAP);
nl_add_attr_mpls(h, bufsize, RTA_DST, ms);
nl_close_attr(h, nest);
nl_add_attr_u16(h, bufsize, RTA_ENCAP_TYPE, LWTUNNEL_ENCAP_MPLS);
}
static inline void
nl_add_attr_via(struct nlmsghdr *h, uint bufsize, ip_addr ipa)
{
struct rtattr *nest = nl_open_attr(h, bufsize, RTA_VIA);
struct rtvia *via = RTA_DATA(nest);
h->nlmsg_len += sizeof(*via);
if (ipa_is_ip4(ipa)) {
ip4_addr ip4 = ipa_to_ip4(ipa);
ip4 = ip4_hton(ip4);
via->rtvia_family = AF_INET;
memcpy(via->rtvia_addr, &ip4, sizeof(ip4));
h->nlmsg_len += sizeof(ip4);
} else {
ip6_addr ip6 = ipa_to_ip6(ipa);
ip6 = ip6_hton(ip6);
via->rtvia_family = AF_INET6;
memcpy(via->rtvia_addr, &ip6, sizeof(ip6));
h->nlmsg_len += sizeof(ip6);
}
nl_close_attr(h, nest);
}
static inline struct rtnexthop *
@ -411,7 +520,7 @@ nl_open_nexthop(struct nlmsghdr *h, uint bufsize)
static inline void
nl_close_nexthop(struct nlmsghdr *h, struct rtnexthop *nh)
{
nh->rtnh_len = (void *)h + NLMSG_ALIGN(h->nlmsg_len) - (void *)nh;
nh->rtnh_len = (void *)h + h->nlmsg_len - (void *)nh;
}
static void
@ -909,6 +1018,15 @@ nh_bufsize(struct mpnh *nh)
return rv;
}
static inline mpls_stack
mpls_from_ea(struct adata *ad) {
mpls_stack s = { .len = ad->length/sizeof(u32) };
int i;
for (i = 0; i < s.len; i++)
s.label[i] = ((u32 *) ad->data)[i];
return s;
}
static int
nl_send_route(struct krt_proto *p, rte *e, struct ea_list *eattrs, int new)
{
@ -933,7 +1051,10 @@ nl_send_route(struct krt_proto *p, rte *e, struct ea_list *eattrs, int new)
r.r.rtm_dst_len = net_pxlen(net->n.addr);
r.r.rtm_protocol = RTPROT_BIRD;
r.r.rtm_scope = RT_SCOPE_UNIVERSE;
nl_add_attr_ipa(&r.h, sizeof(r), RTA_DST, net_prefix(net->n.addr));
if (p->af == AF_MPLS)
nl_add_attr_mpls(&r.h, sizeof(r), RTA_DST, net_mpls(net->n.addr));
else
nl_add_attr_ipa(&r.h, sizeof(r), RTA_DST, net_prefix(net->n.addr));
if (krt_table_id(p) < 256)
r.r.rtm_table = krt_table_id(p);
@ -944,6 +1065,11 @@ nl_send_route(struct krt_proto *p, rte *e, struct ea_list *eattrs, int new)
if (!new)
return nl_exchange(&r.h);
if (ea = ea_find(eattrs, EA_GEN_MPLS_STACK))
if (p->af == AF_MPLS)
nl_add_attr_mpls(&r.h, sizeof(r), RTA_NEWDST, mpls_from_ea(ea->u.ptr));
else
nl_add_attr_mpls_encap(&r.h, sizeof(r), mpls_from_ea(ea->u.ptr));
if (ea = ea_find(eattrs, EA_KRT_METRIC))
nl_add_attr_u32(&r.h, sizeof(r), RTA_PRIORITY, ea->u.data);
@ -977,7 +1103,10 @@ nl_send_route(struct krt_proto *p, rte *e, struct ea_list *eattrs, int new)
case RTD_ROUTER:
r.r.rtm_type = RTN_UNICAST;
nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, a->iface->index);
nl_add_attr_ipa(&r.h, sizeof(r), RTA_GATEWAY, a->gw);
if (p->af == AF_MPLS)
nl_add_attr_via(&r.h, sizeof(r), a->gw);
else
nl_add_attr_ipa(&r.h, sizeof(r), RTA_GATEWAY, a->gw);
break;
case RTD_DEVICE:
r.r.rtm_type = RTN_UNICAST;
@ -1058,9 +1187,9 @@ nl_parse_route(struct nlmsghdr *h, int scan)
net_fill_ip4(&dst, IP4_NONE, 0);
break;
case AF_INET6:
if (!nl_parse_attrs(RTM_RTA(i), rtm_attr_want6, a, sizeof(a)))
return;
case AF_INET6:
if (!nl_parse_attrs(RTM_RTA(i), rtm_attr_want6, a, sizeof(a)))
return;
if (a[RTA_DST])
net_fill_ip6(&dst, rta_get_ip6(a[RTA_DST]), i->rtm_dst_len);
@ -1068,6 +1197,16 @@ nl_parse_route(struct nlmsghdr *h, int scan)
net_fill_ip6(&dst, IP6_NONE, 0);
break;
case AF_MPLS:
if (!nl_parse_attrs(RTM_RTA(i), rtm_attr_want_mpls, a, sizeof(a)))
return;
if (a[RTA_DST])
net_fill_mpls(&dst, rta_get_mpls(a[RTA_DST]).label[0]);
else
return; /* No support for MPLS routes without RTA_DST */
break;
default:
return;
}
@ -1096,7 +1235,7 @@ nl_parse_route(struct nlmsghdr *h, int scan)
SKIP("RTM_DELROUTE in scan\n");
int c = net_classify(&dst);
if ((c < 0) || !(c & IADDR_HOST) || ((c & IADDR_SCOPE_MASK) <= SCOPE_LINK))
if (i->rtm_family != AF_MPLS && ((c < 0) || !(c & IADDR_HOST) || ((c & IADDR_SCOPE_MASK) <= SCOPE_LINK)))
SKIP("strange class/scope\n");
// ignore rtm_scope, it is not a real scope
@ -1160,10 +1299,13 @@ nl_parse_route(struct nlmsghdr *h, int scan)
return;
}
if (a[RTA_GATEWAY])
if ((i->rtm_family != AF_MPLS) && a[RTA_GATEWAY] || (i->rtm_family == AF_MPLS) && a[RTA_VIA])
{
ra.dest = RTD_ROUTER;
ra.gw = rta_get_ipa(a[RTA_GATEWAY]);
if (i->rtm_family == AF_MPLS)
ra.gw = rta_get_via(a[RTA_VIA]);
else
ra.gw = rta_get_ipa(a[RTA_GATEWAY]);
/* Silently skip strange 6to4 routes */
const net_addr_ip6 sit = NET_ADDR_IP6(IP6_NONE, 96);
@ -1210,6 +1352,24 @@ nl_parse_route(struct nlmsghdr *h, int scan)
if (a[RTA_PRIORITY])
e->u.krt.metric = rta_get_u32(a[RTA_PRIORITY]);
if ((i->rtm_family == AF_MPLS) && a[RTA_NEWDST])
{
mpls_stack ms = rta_get_mpls(a[RTA_NEWDST]);
ea_list *ea = alloca(sizeof(ea_list) + sizeof(eattr));
ea->next = ra.eattrs;
ra.eattrs = ea;
ea->flags = EALF_SORTED;
ea->count = 1;
ea->attrs[0].id = EA_KRT_PREFSRC;
ea->attrs[0].flags = 0;
ea->attrs[0].type = EAF_TYPE_INT_SET;
ea->attrs[0].u.ptr = alloca(sizeof(struct adata) + sizeof(u32)*ms.len);
ea->attrs[0].u.ptr->length = sizeof(u32)*ms.len;
for (int j = 0; j < ms.len; j++)
((u32 *)ea->attrs[0].u.ptr->data)[j] = ms.label[j];
}
if (a[RTA_PREFSRC])
{
ip_addr ps = rta_get_ipa(a[RTA_PREFSRC]);
@ -1295,6 +1455,13 @@ krt_do_scan(struct krt_proto *p UNUSED) /* CONFIG_ALL_TABLES_AT_ONCE => p is NUL
nl_parse_route(h, 1);
else
log(L_DEBUG "nl_scan_fire: Unknown packet received (type=%d)", h->nlmsg_type);
nl_request_dump(AF_MPLS, RTM_GETROUTE);
while (h = nl_get_scan())
if (h->nlmsg_type == RTM_NEWROUTE || h->nlmsg_type == RTM_DELROUTE)
nl_parse_route(h, 1);
else
log(L_DEBUG "nl_scan_fire: Unknown packet received (type=%d)", h->nlmsg_type);
}
/*

5
sysdep/unix/krt.c
View File

@ -1144,7 +1144,8 @@ krt_start(struct proto *P)
{
case NET_IP4: p->af = AF_INET; break;
case NET_IP6: p->af = AF_INET6; break;
default: ASSERT(0);
case NET_MPLS: p->af = AF_MPLS; break;
default: log(L_ERR "KRT: Tried to start with strange net type: %d", p->p.net_type); return PS_START; break;
}
add_tail(&krt_proto_list, &p->krt_node);
@ -1255,7 +1256,7 @@ struct protocol proto_unix_kernel = {
.template = "kernel%d",
.attr_class = EAP_KRT,
.preference = DEF_PREF_INHERITED,
.channel_mask = NB_IP,
.channel_mask = NB_IP | NB_MPLS,
.proto_size = sizeof(struct krt_proto),
.config_size = sizeof(struct krt_config),
.preconfig = krt_preconfig,