Commit 71ca7716 authored by Ondřej Zajíček's avatar Ondřej Zajíček

Adds support for several Linux kernel route attributes.

parent 4aef102b
......@@ -1420,12 +1420,20 @@ device routes from BIRD tables to kernel routing tables is restricted
to prevent accidental interference. This restriction can be disabled using
<cf/device routes/ switch.
<p>If your OS supports only a single routing table, you can configure only one
instance of the Kernel protocol. If it supports multiple tables (in order to
allow policy routing; such an OS is for example Linux 2.2), you can run as many instances as you want, but each of
them must be connected to a different BIRD routing table and to a different
<p>If your OS supports only a single routing table, you can configure
only one instance of the Kernel protocol. If it supports multiple
tables (in order to allow policy routing; such an OS is for example
Linux), you can run as many instances as you want, but each of them
must be connected to a different BIRD routing table and to a different
kernel table.
<p>Because the kernel protocol is partially integrated with the
connected routing table, there are two limitations - it is not
possible to connect more kernel protocols to the same routing table
and changing route attributes (even the kernel ones) in an export
filter of a kernel protocol does not work. Both limitations can be
overcome using another routing table and the pipe protocol.
<sect1>Configuration
<p><descrip>
......@@ -1450,12 +1458,27 @@ kernel table.
only on systems supporting multiple routing tables.
</descrip>
<p>The Kernel protocol doesn't define any route attributes.
<sect1>Attributes
<p>The Kernel protocol defines several attributes. These attributes
are translated to appropriate system (and OS-specific) route attributes.
We support these attributes:
<descrip>
<tag>ip <cf/krt_prefsrc/</tag> (Linux) The preferred source address.
Used in source address selection for outgoing packets. Have to
be one of IP addresses of the router.
<tag>int <cf/krt_realm/</tag> (Linux) The realm of the route. Can be
used for traffic classification.
</descrip>
<sect1>Example
<p>A simple configuration can look this way:
<p><code>
protocol kernel {
import all;
export all;
}
</code>
......
......@@ -344,7 +344,8 @@ typedef struct eattr {
#define EAP_BGP 1 /* BGP attributes */
#define EAP_RIP 2 /* RIP */
#define EAP_OSPF 3 /* OSPF */
#define EAP_MAX 4
#define EAP_KRT 4 /* Kernel route attributes */
#define EAP_MAX 5
#define EA_CODE(proto,id) (((proto) << 8) | (id))
#define EA_PROTO(ea) ((ea) >> 8)
......
......@@ -10,7 +10,7 @@ CF_HDR
CF_DECLS
CF_KEYWORDS(ASYNC, KERNEL, TABLE)
CF_KEYWORDS(ASYNC, KERNEL, TABLE, KRT_PREFSRC, KRT_REALM)
CF_GRAMMAR
......@@ -24,6 +24,9 @@ nl_item:
}
;
CF_ADDTO(dynamic_attr, KRT_PREFSRC { $$ = f_new_dynamic_attr(EAF_TYPE_IP_ADDRESS, T_IP, EA_KRT_PREFSRC); })
CF_ADDTO(dynamic_attr, KRT_REALM { $$ = f_new_dynamic_attr(EAF_TYPE_INT, T_INT, EA_KRT_REALM); })
CF_CODE
CF_END
......@@ -18,6 +18,7 @@
#include "nest/route.h"
#include "nest/protocol.h"
#include "nest/iface.h"
#include "lib/alloca.h"
#include "lib/timer.h"
#include "lib/unix.h"
#include "lib/krt.h"
......@@ -618,6 +619,7 @@ nh_bufsize(struct mpnh *nh)
static void
nl_send_route(struct krt_proto *p, rte *e, int new)
{
eattr *ea;
net *net = e->net;
rta *a = e->attrs;
struct {
......@@ -641,6 +643,13 @@ nl_send_route(struct krt_proto *p, rte *e, int new)
r.r.rtm_protocol = RTPROT_BIRD;
r.r.rtm_scope = RT_SCOPE_UNIVERSE;
nl_add_attr_ipa(&r.h, sizeof(r), RTA_DST, net->n.prefix);
if (ea = ea_find(a->eattrs, EA_KRT_PREFSRC))
nl_add_attr_ipa(&r.h, sizeof(r), RTA_PREFSRC, *(ip_addr *)ea->u.ptr->data);
if (ea = ea_find(a->eattrs, EA_KRT_REALM))
nl_add_attr_u32(&r.h, sizeof(r), RTA_FLOW, ea->u.data);
switch (a->dest)
{
case RTD_ROUTER:
......@@ -698,10 +707,9 @@ nl_parse_route(struct nlmsghdr *h, int scan)
struct rtmsg *i;
struct rtattr *a[RTA_CACHEINFO+1];
int new = h->nlmsg_type == RTM_NEWROUTE;
ip_addr dst;
rte *e;
net *net;
u32 oif;
ip_addr dst = IPA_NONE;
u32 oif = ~0;
int src;
if (!(i = nl_checkin(h, sizeof(*i))) || !nl_parse_attrs(RTM_RTA(i), a, sizeof(a)))
......@@ -709,12 +717,14 @@ nl_parse_route(struct nlmsghdr *h, int scan)
if (i->rtm_family != BIRD_AF)
return;
if ((a[RTA_DST] && RTA_PAYLOAD(a[RTA_DST]) != sizeof(ip_addr)) ||
(a[RTA_OIF] && RTA_PAYLOAD(a[RTA_OIF]) != 4) ||
(a[RTA_PRIORITY] && RTA_PAYLOAD(a[RTA_PRIORITY]) != 4) ||
#ifdef IPV6
(a[RTA_IIF] && RTA_PAYLOAD(a[RTA_IIF]) != 4) ||
#endif
(a[RTA_GATEWAY] && RTA_PAYLOAD(a[RTA_GATEWAY]) != sizeof(ip_addr)))
(a[RTA_OIF] && RTA_PAYLOAD(a[RTA_OIF]) != 4) ||
(a[RTA_GATEWAY] && RTA_PAYLOAD(a[RTA_GATEWAY]) != sizeof(ip_addr)) ||
(a[RTA_PRIORITY] && RTA_PAYLOAD(a[RTA_PRIORITY]) != 4) ||
(a[RTA_PREFSRC] && RTA_PAYLOAD(a[RTA_PREFSRC]) != sizeof(ip_addr)) ||
(a[RTA_FLOW] && RTA_PAYLOAD(a[RTA_OIF]) != 4))
{
log(L_ERR "KRT: Malformed message received");
return;
......@@ -725,13 +735,9 @@ nl_parse_route(struct nlmsghdr *h, int scan)
memcpy(&dst, RTA_DATA(a[RTA_DST]), sizeof(dst));
ipa_ntoh(dst);
}
else
dst = IPA_NONE;
if (a[RTA_OIF])
memcpy(&oif, RTA_DATA(a[RTA_OIF]), sizeof(oif));
else
oif = ~0;
DBG("KRT: Got %I/%d, type=%d, oif=%d, table=%d, prid=%d, proto=%s\n", dst, i->rtm_dst_len, i->rtm_type, oif, i->rtm_table, i->rtm_protocol, p->p.name);
......@@ -782,7 +788,7 @@ nl_parse_route(struct nlmsghdr *h, int scan)
src = KRT_SRC_ALIEN;
}
net = net_get(p->p.table, dst, i->rtm_dst_len);
net *net = net_get(p->p.table, dst, i->rtm_dst_len);
rta ra = {
.proto = &p->p,
......@@ -871,15 +877,49 @@ nl_parse_route(struct nlmsghdr *h, int scan)
return;
}
e = rte_get_temp(&ra);
rte *e = rte_get_temp(&ra);
e->net = net;
e->u.krt.src = src;
e->u.krt.proto = i->rtm_protocol;
e->u.krt.type = i->rtm_type;
if (a[RTA_PRIORITY])
memcpy(&e->u.krt.metric, RTA_DATA(a[RTA_PRIORITY]), sizeof(e->u.krt.metric));
else
e->u.krt.metric = 0;
if (a[RTA_PREFSRC])
{
ip_addr ps;
memcpy(&ps, RTA_DATA(a[RTA_PREFSRC]), sizeof(ps));
ipa_ntoh(ps);
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_IP_ADDRESS;
ea->attrs[0].u.ptr = alloca(sizeof(struct adata) + sizeof(ps));
ea->attrs[0].u.ptr->length = sizeof(ps);
memcpy(ea->attrs[0].u.ptr->data, &ps, sizeof(ps));
}
if (a[RTA_FLOW])
{
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_REALM;
ea->attrs[0].flags = 0;
ea->attrs[0].type = EAF_TYPE_INT;
memcpy(&ea->attrs[0].u.data, RTA_DATA(a[RTA_FLOW]), 4);
}
if (scan)
krt_got_route(p, e);
else
......
......@@ -890,6 +890,7 @@ krt_init(struct proto_config *c)
p->p.accept_ra_types = RA_OPTIMAL;
p->p.import_control = krt_import_control;
p->p.rt_notify = krt_notify;
return &p->p;
}
......@@ -907,15 +908,35 @@ krt_reconfigure(struct proto *p, struct proto_config *new)
;
}
static int
krt_get_attr(eattr * a, byte * buf, int buflen UNUSED)
{
switch (a->id)
{
case EA_KRT_PREFSRC:
bsprintf(buf, "prefsrc");
return GA_NAME;
case EA_KRT_REALM:
bsprintf(buf, "realm");
return GA_NAME;
default:
return GA_UNKNOWN;
}
}
struct protocol proto_unix_kernel = {
name: "Kernel",
template: "kernel%d",
attr_class: EAP_KRT,
preconfig: krt_preconfig,
postconfig: krt_postconfig,
init: krt_init,
start: krt_start,
shutdown: krt_shutdown,
reconfigure: krt_reconfigure,
get_attr: krt_get_attr,
#ifdef KRT_ALLOW_LEARN
dump: krt_dump,
dump_attrs: krt_dump_attrs,
......
......@@ -30,6 +30,10 @@ struct kif_proto;
#define KRF_INSTALLED 0x80 /* This route should be installed in the kernel */
#define EA_KRT_PREFSRC EA_CODE(EAP_KRT, 0)
#define EA_KRT_REALM EA_CODE(EAP_KRT, 1)
/* Whenever we recognize our own routes, we allow learing of foreign routes */
#ifdef CONFIG_SELF_CONSCIOUS
......
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