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Netlink: MPLS routes in kernel, not fully working yet.
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
parent
21d358f074
commit
45f01fb32e
43
lib/mpls.h
43
lib/mpls.h
@ -11,10 +11,53 @@
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#define _BIRD_MPLS_H_
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#define MPLS_STACK_LENGTH 8 /* Adjust this if you need deeper MPLS stack */
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#define MPLS_PXLEN 20 /* Length of the label in bits. Constant. */
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/*
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* RFC 3032 updated by RFC 5462:
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*
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* 0 1 2 3
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* 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
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Label
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* | Label | TC |S| TTL | Stack
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* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Entry
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*
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* Label: Label Value, 20 bits
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* TC: Traffic Class, 3 bits
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* S: Bottom of Stack, 1 bit
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* TTL: Time to Live, 8 bits
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*/
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typedef struct mpls_stack {
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u8 len;
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u32 label[MPLS_STACK_LENGTH];
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} mpls_stack;
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static inline char * const mpls_hton(mpls_stack s) {
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static char buf[MPLS_STACK_LENGTH*4];
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int i;
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for (i = 0; i < s.len; i++) {
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buf[i*4 + 0] = s.label[i] >> 12;
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buf[i*4 + 1] = s.label[i] >> 4;
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buf[i*4 + 2] = (s.label[i] << 4) | (i == s.len - 1 ? 0x1 : 0);
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buf[i*4 + 3] = 0;
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}
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return buf;
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}
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static inline int mpls_buflen(const char *buf) {
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// Looking for the Bottom of Stack set to 4.
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int i;
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for (i = 0; !(buf[i++*4 + 2] & 0x1); );
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return i*4;
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}
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static inline mpls_stack mpls_ntoh(const char *buf) {
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mpls_stack s = { .len = mpls_buflen(buf) };
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int i;
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for (i = 0; i < s.len; i++)
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s.label[i] = (buf[i*4 + 0] << 12) | (buf[i*4 + 1] << 4) | (buf[i*4 + 2] >> 4);
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return s;
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}
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#endif
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15
lib/net.h
15
lib/net.h
@ -11,6 +11,7 @@
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#define _BIRD_NET_H_
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#include "lib/ip.h"
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#include "lib/mpls.h"
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#define NET_IP4 1
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@ -134,7 +135,7 @@ extern const u16 net_max_text_length[];
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((net_addr_roa6) { NET_ROA6, pxlen, sizeof(net_addr_roa6), prefix, max_pxlen, asn })
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#define NET_ADDR_MPLS(label) \
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((net_addr_mpls) { NET_MPLS, 0, sizeof(net_addr_mpls), label })
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((net_addr_mpls) { NET_MPLS, MPLS_PXLEN, sizeof(net_addr_mpls), label })
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static inline void net_fill_ip4(net_addr *a, ip4_addr prefix, uint pxlen)
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@ -211,6 +212,18 @@ static inline ip_addr net_prefix(const net_addr *a)
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}
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}
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static inline mpls_stack net_mpls(const net_addr *a)
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{
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mpls_stack ms;
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if (a->type == NET_MPLS) {
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ms.len = 1;
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ms.label[0] = ((net_addr_mpls *) a)->label;
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return ms;
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}
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bug("Can't call net_mpls on non-mpls net_addr");
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}
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static inline uint net4_pxlen(const net_addr *a)
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{ return a->pxlen; }
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@ -16,6 +16,10 @@
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#define CONFIG_RESTRICTED_PRIVILEGES
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#ifndef AF_MPLS
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#define AF_MPLS 28
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#endif
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/*
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Link: sysdep/linux
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Link: sysdep/unix
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@ -26,10 +26,12 @@
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#include "lib/socket.h"
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#include "lib/string.h"
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#include "lib/hash.h"
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#include "lib/mpls.h"
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#include "conf/conf.h"
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#include <asm/types.h>
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#include <linux/if.h>
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#include <linux/lwtunnel.h>
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#include <linux/netlink.h>
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#include <linux/rtnetlink.h>
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@ -46,6 +48,25 @@
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#define RTA_TABLE 15
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#endif
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#ifndef RTA_VIA
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#define RTA_VIA 18
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#endif
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#ifndef RTA_NEWDST
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#define RTA_NEWDST 19
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#endif
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#ifndef RTA_ENCAP_TYPE
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#define RTA_ENCAP_TYPE 21
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#endif
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#ifndef RTA_ENCAP
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#define RTA_ENCAP 22
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#endif
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#ifndef AF_MPLS
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#define AF_MPLS 28
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#endif
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/*
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* Synchronous Netlink interface
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@ -256,7 +277,7 @@ static struct nl_want_attrs ifa_attr_want6[BIRD_IFA_MAX] = {
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};
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#define BIRD_RTA_MAX (RTA_TABLE+1)
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#define BIRD_RTA_MAX (RTA_ENCAP+1)
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static struct nl_want_attrs mpnh_attr_want4[BIRD_RTA_MAX] = {
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[RTA_GATEWAY] = { 1, 1, sizeof(ip4_addr) },
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@ -272,6 +293,8 @@ static struct nl_want_attrs rtm_attr_want4[BIRD_RTA_MAX] = {
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[RTA_MULTIPATH] = { 1, 0, 0 },
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[RTA_FLOW] = { 1, 1, sizeof(u32) },
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[RTA_TABLE] = { 1, 1, sizeof(u32) },
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[RTA_ENCAP_TYPE]= { 1, 1, sizeof(u16) },
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[RTA_ENCAP] = { 1, 0, 0 },
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};
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static struct nl_want_attrs rtm_attr_want6[BIRD_RTA_MAX] = {
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@ -284,6 +307,20 @@ static struct nl_want_attrs rtm_attr_want6[BIRD_RTA_MAX] = {
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[RTA_METRICS] = { 1, 0, 0 },
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[RTA_FLOW] = { 1, 1, sizeof(u32) },
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[RTA_TABLE] = { 1, 1, sizeof(u32) },
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[RTA_ENCAP_TYPE]= { 1, 1, sizeof(u16) },
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[RTA_ENCAP] = { 1, 0, 0 },
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};
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static struct nl_want_attrs rtm_attr_want_mpls[BIRD_RTA_MAX] = {
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[RTA_DST] = { 1, 1, sizeof(u32) },
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[RTA_IIF] = { 1, 1, sizeof(u32) },
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[RTA_OIF] = { 1, 1, sizeof(u32) },
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[RTA_PRIORITY] = { 1, 1, sizeof(u32) },
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[RTA_METRICS] = { 1, 0, 0 },
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[RTA_FLOW] = { 1, 1, sizeof(u32) },
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[RTA_TABLE] = { 1, 1, sizeof(u32) },
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[RTA_VIA] = { 1, 0, 0 },
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[RTA_NEWDST] = { 1, 0, 0 },
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};
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@ -333,6 +370,30 @@ static inline ip_addr rta_get_ipa(struct rtattr *a)
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return ipa_from_ip6(rta_get_ip6(a));
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}
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static inline ip_addr rta_get_via(struct rtattr *a)
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{
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struct rtvia *v = RTA_DATA(a);
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switch(v->rtvia_family) {
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case AF_INET: return ipa_from_ip4(ip4_ntoh(*(ip4_addr *) v->rtvia_addr));
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case AF_INET6: return ipa_from_ip6(ip6_ntoh(*(ip6_addr *) v->rtvia_addr));
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}
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return IPA_NONE;
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}
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static inline mpls_stack rta_get_mpls(struct rtattr *a)
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{
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mpls_stack ms = { .len = RTA_PAYLOAD(a) / 4 };
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for (int i = 0; i < ms.len; i++) {
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ms.label[i] = (((u8 *)RTA_DATA(a))[i*4 + 0] << 12)
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| (((u8 *)RTA_DATA(a))[i*4 + 1] << 4)
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| (((u8 *)RTA_DATA(a))[i*4 + 2] >> 4);
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if (!!(((u8 *)RTA_DATA(a))[i*4 + 2] & 1) != (i+1 == ms.len))
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log(L_WARN "KRT: Received a route with mismatched MPLS BoS bit, ignoring");
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}
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return ms;
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}
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struct rtattr *
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nl_add_attr(struct nlmsghdr *h, uint bufsize, uint code, const void *data, uint dlen)
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{
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@ -353,6 +414,24 @@ nl_add_attr(struct nlmsghdr *h, uint bufsize, uint code, const void *data, uint
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return a;
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}
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static inline struct rtattr *
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nl_open_attr(struct nlmsghdr *h, uint bufsize, uint code)
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{
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return nl_add_attr(h, bufsize, code, NULL, 0);
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}
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static inline void
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nl_close_attr(struct nlmsghdr *h, struct rtattr *a)
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{
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a->rta_len = (void *)h + h->nlmsg_len - (void *)a;
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}
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static inline void
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nl_add_attr_u16(struct nlmsghdr *h, uint bufsize, int code, u16 data)
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{
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nl_add_attr(h, bufsize, code, &data, 2);
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}
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static inline void
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nl_add_attr_u32(struct nlmsghdr *h, uint bufsize, int code, u32 data)
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{
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@ -382,16 +461,46 @@ nl_add_attr_ipa(struct nlmsghdr *h, uint bufsize, int code, ip_addr ipa)
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nl_add_attr_ip6(h, bufsize, code, ipa_to_ip6(ipa));
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}
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static inline struct rtattr *
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nl_open_attr(struct nlmsghdr *h, uint bufsize, uint code)
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static inline void
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nl_add_attr_mpls(struct nlmsghdr *h, uint bufsize, int code, mpls_stack ms)
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{
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return nl_add_attr(h, bufsize, code, NULL, 0);
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const char *buf = mpls_hton(ms);
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nl_add_attr(h, bufsize, code, buf, mpls_buflen(buf));
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}
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static inline void
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nl_close_attr(struct nlmsghdr *h, struct rtattr *a)
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nl_add_attr_mpls_encap(struct nlmsghdr *h, uint bufsize, mpls_stack ms)
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{
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a->rta_len = (void *)h + NLMSG_ALIGN(h->nlmsg_len) - (void *)a;
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struct rtattr *nest = nl_open_attr(h, bufsize, RTA_ENCAP);
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nl_add_attr_mpls(h, bufsize, RTA_DST, ms);
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nl_close_attr(h, nest);
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nl_add_attr_u16(h, bufsize, RTA_ENCAP_TYPE, LWTUNNEL_ENCAP_MPLS);
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}
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static inline void
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nl_add_attr_via(struct nlmsghdr *h, uint bufsize, ip_addr ipa)
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{
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struct rtattr *nest = nl_open_attr(h, bufsize, RTA_VIA);
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struct rtvia *via = RTA_DATA(nest);
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h->nlmsg_len += sizeof(*via);
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if (ipa_is_ip4(ipa)) {
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ip4_addr ip4 = ipa_to_ip4(ipa);
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ip4 = ip4_hton(ip4);
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via->rtvia_family = AF_INET;
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memcpy(via->rtvia_addr, &ip4, sizeof(ip4));
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h->nlmsg_len += sizeof(ip4);
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} else {
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ip6_addr ip6 = ipa_to_ip6(ipa);
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ip6 = ip6_hton(ip6);
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via->rtvia_family = AF_INET6;
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memcpy(via->rtvia_addr, &ip6, sizeof(ip6));
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h->nlmsg_len += sizeof(ip6);
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}
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nl_close_attr(h, nest);
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}
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static inline struct rtnexthop *
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@ -411,7 +520,7 @@ nl_open_nexthop(struct nlmsghdr *h, uint bufsize)
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static inline void
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nl_close_nexthop(struct nlmsghdr *h, struct rtnexthop *nh)
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{
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nh->rtnh_len = (void *)h + NLMSG_ALIGN(h->nlmsg_len) - (void *)nh;
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nh->rtnh_len = (void *)h + h->nlmsg_len - (void *)nh;
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}
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static void
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@ -909,6 +1018,15 @@ nh_bufsize(struct mpnh *nh)
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return rv;
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}
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static inline mpls_stack
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mpls_from_ea(struct adata *ad) {
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mpls_stack s = { .len = ad->length/sizeof(u32) };
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int i;
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for (i = 0; i < s.len; i++)
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s.label[i] = ((u32 *) ad->data)[i];
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return s;
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}
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static int
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nl_send_route(struct krt_proto *p, rte *e, struct ea_list *eattrs, int new)
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{
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@ -933,6 +1051,9 @@ nl_send_route(struct krt_proto *p, rte *e, struct ea_list *eattrs, int new)
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r.r.rtm_dst_len = net_pxlen(net->n.addr);
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r.r.rtm_protocol = RTPROT_BIRD;
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r.r.rtm_scope = RT_SCOPE_UNIVERSE;
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if (p->af == AF_MPLS)
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nl_add_attr_mpls(&r.h, sizeof(r), RTA_DST, net_mpls(net->n.addr));
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else
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nl_add_attr_ipa(&r.h, sizeof(r), RTA_DST, net_prefix(net->n.addr));
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if (krt_table_id(p) < 256)
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@ -944,6 +1065,11 @@ nl_send_route(struct krt_proto *p, rte *e, struct ea_list *eattrs, int new)
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if (!new)
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return nl_exchange(&r.h);
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if (ea = ea_find(eattrs, EA_GEN_MPLS_STACK))
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if (p->af == AF_MPLS)
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nl_add_attr_mpls(&r.h, sizeof(r), RTA_NEWDST, mpls_from_ea(ea->u.ptr));
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else
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nl_add_attr_mpls_encap(&r.h, sizeof(r), mpls_from_ea(ea->u.ptr));
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if (ea = ea_find(eattrs, EA_KRT_METRIC))
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nl_add_attr_u32(&r.h, sizeof(r), RTA_PRIORITY, ea->u.data);
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@ -977,6 +1103,9 @@ nl_send_route(struct krt_proto *p, rte *e, struct ea_list *eattrs, int new)
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case RTD_ROUTER:
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r.r.rtm_type = RTN_UNICAST;
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nl_add_attr_u32(&r.h, sizeof(r), RTA_OIF, a->iface->index);
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if (p->af == AF_MPLS)
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nl_add_attr_via(&r.h, sizeof(r), a->gw);
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else
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nl_add_attr_ipa(&r.h, sizeof(r), RTA_GATEWAY, a->gw);
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break;
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case RTD_DEVICE:
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@ -1068,6 +1197,16 @@ nl_parse_route(struct nlmsghdr *h, int scan)
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net_fill_ip6(&dst, IP6_NONE, 0);
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break;
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case AF_MPLS:
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if (!nl_parse_attrs(RTM_RTA(i), rtm_attr_want_mpls, a, sizeof(a)))
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return;
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if (a[RTA_DST])
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net_fill_mpls(&dst, rta_get_mpls(a[RTA_DST]).label[0]);
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else
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return; /* No support for MPLS routes without RTA_DST */
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break;
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default:
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return;
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}
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@ -1096,7 +1235,7 @@ nl_parse_route(struct nlmsghdr *h, int scan)
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SKIP("RTM_DELROUTE in scan\n");
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int c = net_classify(&dst);
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if ((c < 0) || !(c & IADDR_HOST) || ((c & IADDR_SCOPE_MASK) <= SCOPE_LINK))
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if (i->rtm_family != AF_MPLS && ((c < 0) || !(c & IADDR_HOST) || ((c & IADDR_SCOPE_MASK) <= SCOPE_LINK)))
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SKIP("strange class/scope\n");
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// ignore rtm_scope, it is not a real scope
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@ -1160,9 +1299,12 @@ nl_parse_route(struct nlmsghdr *h, int scan)
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return;
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}
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if (a[RTA_GATEWAY])
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if ((i->rtm_family != AF_MPLS) && a[RTA_GATEWAY] || (i->rtm_family == AF_MPLS) && a[RTA_VIA])
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{
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ra.dest = RTD_ROUTER;
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if (i->rtm_family == AF_MPLS)
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ra.gw = rta_get_via(a[RTA_VIA]);
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else
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ra.gw = rta_get_ipa(a[RTA_GATEWAY]);
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/* Silently skip strange 6to4 routes */
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@ -1210,6 +1352,24 @@ nl_parse_route(struct nlmsghdr *h, int scan)
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if (a[RTA_PRIORITY])
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e->u.krt.metric = rta_get_u32(a[RTA_PRIORITY]);
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if ((i->rtm_family == AF_MPLS) && a[RTA_NEWDST])
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{
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mpls_stack ms = rta_get_mpls(a[RTA_NEWDST]);
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ea_list *ea = alloca(sizeof(ea_list) + sizeof(eattr));
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ea->next = ra.eattrs;
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ra.eattrs = ea;
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ea->flags = EALF_SORTED;
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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);
|
||||
}
|
||||
|
||||
/*
|
||||
|
||||
@ -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,
|
||||
|
||||
Loading…
Reference in New Issue
Block a user