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-rw-r--r--sysdep/linux/netlink.c243
1 files changed, 37 insertions, 206 deletions
diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c
index bc65e0d2..e41eb32d 100644
--- a/sysdep/linux/netlink.c
+++ b/sysdep/linux/netlink.c
@@ -74,51 +74,16 @@
#endif
#define krt_ipv4(p) ((p)->af == AF_INET)
-#define krt_ecmp6(p) ((p)->af == AF_INET6)
const int rt_default_ecmp = 16;
-/*
- * Structure nl_parse_state keeps state of received route processing. Ideally,
- * we could just independently parse received Netlink messages and immediately
- * propagate received routes to the rest of BIRD, but older Linux kernel (before
- * version 4.11) represents and announces IPv6 ECMP routes not as one route with
- * multiple next hops (like RTA_MULTIPATH in IPv4 ECMP), but as a sequence of
- * routes with the same prefix. More recent kernels work as with IPv4.
- *
- * Therefore, BIRD keeps currently processed route in nl_parse_state structure
- * and postpones its propagation until we expect it to be final; i.e., when
- * non-matching route is received or when the scan ends. When another matching
- * route is received, it is merged with the already processed route to form an
- * ECMP route. Note that merging is done only for IPv6 (merge == 1), but the
- * postponing is done in both cases (for simplicity). All IPv4 routes or IPv6
- * routes with RTA_MULTIPATH set are just considered non-matching.
- *
- * This is ignored for asynchronous notifications (every notification is handled
- * as a separate route). It is not an issue for our routes, as we ignore such
- * notifications anyways. But importing alien IPv6 ECMP routes does not work
- * properly with older kernels.
- *
- * Whatever the kernel version is, IPv6 ECMP routes are sent as multiple routes
- * for the same prefix.
- */
-
struct nl_parse_state
{
+ struct krt_proto *proto;
struct linpool *pool;
int scan;
- int merge;
-
- net *net;
- rta *attrs;
- struct krt_proto *proto;
- s8 new;
- s8 krt_src;
- u8 krt_type;
- u8 krt_proto;
- u32 krt_metric;
- u32 rta_flow; /* Used during parsing */
+ u32 rta_flow;
};
/*
@@ -1341,7 +1306,7 @@ nh_bufsize(struct nexthop *nh)
}
static int
-nl_send_route(struct krt_proto *p, rte *e, int op, int dest, struct nexthop *nh)
+nl_send_route(struct krt_proto *p, rte *e, int op)
{
eattr *ea;
net *net = e->net;
@@ -1425,15 +1390,17 @@ nl_send_route(struct krt_proto *p, rte *e, int op, int dest, struct nexthop *nh)
/* For route delete, we do not specify remaining route attributes */
if (op == NL_OP_DELETE)
- goto dest;
+ goto done;
/* Default scope is LINK for device routes, UNIVERSE otherwise */
if (p->af == AF_MPLS)
r->r.rtm_scope = RT_SCOPE_UNIVERSE;
else if (ea = ea_find(eattrs, EA_KRT_SCOPE))
r->r.rtm_scope = ea->u.data;
+ else if (a->dest == RTD_UNICAST && ipa_zero(a->nh.gw))
+ r->r.rtm_scope = RT_SCOPE_LINK;
else
- r->r.rtm_scope = (dest == RTD_UNICAST && ipa_zero(nh->gw)) ? RT_SCOPE_LINK : RT_SCOPE_UNIVERSE;
+ r->r.rtm_scope = RT_SCOPE_UNIVERSE;
if (ea = ea_find(eattrs, EA_KRT_PREFSRC))
nl_add_attr_ipa(&r->h, rsize, RTA_PREFSRC, *(ip_addr *)ea->u.ptr->data);
@@ -1456,13 +1423,12 @@ nl_send_route(struct krt_proto *p, rte *e, int op, int dest, struct nexthop *nh)
if (metrics[0])
nl_add_metrics(&r->h, rsize, metrics, KRT_METRICS_MAX);
-
-dest:
- switch (dest)
+ switch (a->dest)
{
case RTD_UNICAST:
r->r.rtm_type = RTN_UNICAST;
- if (nh->next && !krt_ecmp6(p))
+ struct nexthop *nh = &(a->nh);
+ if (nh->next)
nl_add_multipath(&r->h, rsize, nh, p->af, eattrs);
else
{
@@ -1488,82 +1454,27 @@ dest:
bug("krt_capable inconsistent with nl_send_route");
}
+done:
/* Ignore missing for DELETE */
return nl_exchange(&r->h, (op == NL_OP_DELETE));
}
-static inline int
-nl_add_rte(struct krt_proto *p, rte *e)
-{
- rta *a = e->attrs;
- int err = 0;
-
- if (krt_ecmp6(p) && a->nh.next)
- {
- struct nexthop *nh = &(a->nh);
-
- err = nl_send_route(p, e, NL_OP_ADD, RTD_UNICAST, nh);
- if (err < 0)
- return err;
-
- for (nh = nh->next; nh; nh = nh->next)
- err += nl_send_route(p, e, NL_OP_APPEND, RTD_UNICAST, nh);
-
- return err;
- }
-
- return nl_send_route(p, e, NL_OP_ADD, a->dest, &(a->nh));
-}
-
-static inline int
-nl_delete_rte(struct krt_proto *p, rte *e)
-{
- int err = 0;
-
- /* For IPv6, we just repeatedly request DELETE until we get error */
- do
- err = nl_send_route(p, e, NL_OP_DELETE, RTD_NONE, NULL);
- while (krt_ecmp6(p) && !err);
-
- return err;
-}
-
-static inline int
-nl_replace_rte(struct krt_proto *p, rte *e)
-{
- rta *a = e->attrs;
- return nl_send_route(p, e, NL_OP_REPLACE, a->dest, &(a->nh));
-}
-
-
void
krt_replace_rte(struct krt_proto *p, net *n UNUSED, rte *new, rte *old)
{
int err = 0;
- /*
- * We use NL_OP_REPLACE for IPv4, it has an issue with not checking for
- * matching rtm_protocol, but that is OK when dedicated priority is used.
- *
- * We do not use NL_OP_REPLACE for IPv6, as it has broken semantics for ECMP
- * and with some kernel versions ECMP replace crashes kernel. Would need more
- * testing and checks for kernel versions.
- *
- * For IPv6, we use NL_OP_DELETE and then NL_OP_ADD. We also do not trust the
- * old route value, so we do not try to optimize IPv6 ECMP reconfigurations.
- */
-
- if (krt_ipv4(p) && old && new)
+ if (old && new)
{
- err = nl_replace_rte(p, new);
+ err = nl_send_route(p, new, NL_OP_REPLACE);
}
else
{
if (old)
- nl_delete_rte(p, old);
+ nl_send_route(p, old, NL_OP_DELETE);
if (new)
- err = nl_add_rte(p, new);
+ err = nl_send_route(p, new, NL_OP_ADD);
}
if (new)
@@ -1575,61 +1486,6 @@ krt_replace_rte(struct krt_proto *p, net *n UNUSED, rte *new, rte *old)
}
}
-static int
-nl_mergable_route(struct nl_parse_state *s, net *net, struct krt_proto *p, uint priority, uint krt_type, uint rtm_family)
-{
- /* Route merging is used for IPv6 scans */
- if (!s->scan || (rtm_family != AF_INET6))
- return 0;
-
- /* Saved and new route must have same network, proto/table, and priority */
- if ((s->net != net) || (s->proto != p) || (s->krt_metric != priority))
- return 0;
-
- /* Both must be regular unicast routes */
- if ((s->krt_type != RTN_UNICAST) || (krt_type != RTN_UNICAST))
- return 0;
-
- return 1;
-}
-
-static void
-nl_announce_route(struct nl_parse_state *s)
-{
- rte *e = rte_get_temp(s->attrs);
- e->net = s->net;
- e->u.krt.src = s->krt_src;
- e->u.krt.proto = s->krt_proto;
- e->u.krt.seen = 0;
- e->u.krt.best = 0;
- e->u.krt.metric = s->krt_metric;
-
- if (s->scan)
- krt_got_route(s->proto, e);
- else
- krt_got_route_async(s->proto, e, s->new);
-
- s->net = NULL;
- s->attrs = NULL;
- s->proto = NULL;
- lp_flush(s->pool);
-}
-
-static inline void
-nl_parse_begin(struct nl_parse_state *s, int scan)
-{
- memset(s, 0, sizeof (struct nl_parse_state));
- s->pool = nl_linpool;
- s->scan = scan;
-}
-
-static inline void
-nl_parse_end(struct nl_parse_state *s)
-{
- if (s->net)
- nl_announce_route(s);
-}
-
#define SKIP0(ARG, ...) do { DBG("KRT: Ignoring route - " ARG, ##__VA_ARGS__); return; } while(0)
#define SKIP(ARG, ...) do { DBG("KRT: Ignoring route %N - " ARG, &dst, ##__VA_ARGS__); return; } while(0)
@@ -1767,9 +1623,6 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
net *net = net_get(p->p.main_channel->table, n);
- if (s->net && !nl_mergable_route(s, net, p, priority, i->rtm_type, i->rtm_family))
- nl_announce_route(s);
-
rta *ra = lp_allocz(s->pool, RTA_MAX_SIZE);
ra->src = p->p.main_source;
ra->source = RTS_INHERIT;
@@ -1951,53 +1804,30 @@ nl_parse_route(struct nl_parse_state *s, struct nlmsghdr *h)
}
}
- /*
- * Ideally, now we would send the received route to the rest of kernel code.
- * But IPv6 ECMP routes before 4.11 are sent as a sequence of routes, so we
- * postpone it and merge next hops until the end of the sequence. Note that
- * when doing merging of next hops, we expect the new route to be unipath.
- * Otherwise, we ignore additional next hops in nexthop_insert().
- */
+ rte *e = rte_get_temp(ra);
+ e->net = net;
+ e->u.krt.src = krt_src;
+ e->u.krt.proto = i->rtm_protocol;
+ e->u.krt.seen = 0;
+ e->u.krt.best = 0;
+ e->u.krt.metric = priority;
- if (!s->net)
- {
- /* Store the new route */
- s->net = net;
- s->attrs = ra;
- s->proto = p;
- s->new = new;
- s->krt_src = krt_src;
- s->krt_type = i->rtm_type;
- s->krt_proto = i->rtm_protocol;
- s->krt_metric = priority;
- }
+ if (s->scan)
+ krt_got_route(p, e);
else
- {
- /* Merge next hops with the stored route */
- rta *oa = s->attrs;
-
- struct nexthop *nhs = &oa->nh;
- nexthop_insert(&nhs, &ra->nh);
+ krt_got_route_async(p, e, new);
- /* Perhaps new nexthop is inserted at the first position */
- if (nhs == &ra->nh)
- {
- /* Swap rtas */
- s->attrs = ra;
-
- /* Keep old eattrs */
- ra->eattrs = oa->eattrs;
- }
- }
+ lp_flush(s->pool);
}
void
krt_do_scan(struct krt_proto *p)
{
- struct nlmsghdr *h;
- struct nl_parse_state s;
-
- nl_parse_begin(&s, 1);
+ struct nl_parse_state s = {
+ .proto = p,
+ .pool = nl_linpool,
+ .scan = 1,
+ };
/* Table-specific scan or shared scan */
if (p)
@@ -2005,6 +1835,7 @@ krt_do_scan(struct krt_proto *p)
else
nl_request_dump_route(AF_UNSPEC, 0);
+ struct nlmsghdr *h;
while (h = nl_get_scan())
{
if (h->nlmsg_type == RTM_NEWROUTE || h->nlmsg_type == RTM_DELROUTE)
@@ -2012,8 +1843,6 @@ krt_do_scan(struct krt_proto *p)
else
log(L_DEBUG "nl_scan_fire: Unknown packet received (type=%d)", h->nlmsg_type);
}
-
- nl_parse_end(&s);
}
/*
@@ -2028,16 +1857,18 @@ static struct config *nl_last_config; /* For tracking changes to nl_async_bufsiz
static void
nl_async_msg(struct nlmsghdr *h)
{
- struct nl_parse_state s;
+ struct nl_parse_state s = {
+ .proto = NULL,
+ .pool = nl_linpool,
+ .scan = 0,
+ };
switch (h->nlmsg_type)
{
case RTM_NEWROUTE:
case RTM_DELROUTE:
DBG("KRT: Received async route notification (%d)\n", h->nlmsg_type);
- nl_parse_begin(&s, 0);
nl_parse_route(&s, h);
- nl_parse_end(&s);
break;
case RTM_NEWLINK:
case RTM_DELLINK:
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-27 14:10:57 +0000