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-rw-r--r--sysdep/cf/README1
-rw-r--r--sysdep/cf/linux.h1
-rw-r--r--sysdep/linux/netlink.c326
-rw-r--r--sysdep/unix/krt.c72
-rw-r--r--sysdep/unix/krt.h4
5 files changed, 147 insertions, 257 deletions
diff --git a/sysdep/cf/README b/sysdep/cf/README
index 9a7a4afa..68078bbe 100644
--- a/sysdep/cf/README
+++ b/sysdep/cf/README
@@ -4,7 +4,6 @@ Available configuration variables:
CONFIG_AUTO_ROUTES Device routes are added automagically by the kernel
CONFIG_SELF_CONSCIOUS We're able to recognize whether route was installed by us
CONFIG_MULTIPLE_TABLES The kernel supports multiple routing tables
-CONFIG_ALL_TABLES_AT_ONCE Kernel scanner wants to process all tables at once
CONFIG_SINGLE_ROUTE There is only one route per network
CONFIG_MC_PROPER_SRC Multicast packets have source address according to socket saddr field
diff --git a/sysdep/cf/linux.h b/sysdep/cf/linux.h
index 047d3764..c640bef4 100644
--- a/sysdep/cf/linux.h
+++ b/sysdep/cf/linux.h
@@ -9,7 +9,6 @@
#define CONFIG_AUTO_ROUTES
#define CONFIG_SELF_CONSCIOUS
#define CONFIG_MULTIPLE_TABLES
-#define CONFIG_ALL_TABLES_AT_ONCE
#define CONFIG_IP6_SADR_KERNEL
#define CONFIG_MC_PROPER_SRC
diff --git a/sysdep/linux/netlink.c b/sysdep/linux/netlink.c
index e103c8ef..342b746c 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;
};
/*
@@ -161,16 +126,13 @@ nl_open_sock(struct nl_sock *nl)
}
}
-static void
+static int
nl_set_strict_dump(struct nl_sock *nl UNUSED, int strict UNUSED)
{
- /*
- * Strict checking is not necessary, it improves behavior on newer kernels.
- * If it is not available (missing SOL_NETLINK compile-time, or ENOPROTOOPT
- * run-time), we can just ignore it.
- */
#ifdef SOL_NETLINK
- setsockopt(nl->fd, SOL_NETLINK, NETLINK_GET_STRICT_CHK, &strict, sizeof(strict));
+ return setsockopt(nl->fd, SOL_NETLINK, NETLINK_GET_STRICT_CHK, &strict, sizeof(strict));
+#else
+ return -1;
#endif
}
@@ -198,10 +160,17 @@ nl_cfg_rx_buffer_size(struct config *cfg)
static void
nl_open(void)
{
+ if ((nl_scan.fd >= 0) && (nl_req.fd >= 0))
+ return;
+
nl_open_sock(&nl_scan);
nl_open_sock(&nl_req);
- nl_set_strict_dump(&nl_scan, 1);
+ if (nl_set_strict_dump(&nl_scan, 1) < 0)
+ {
+ log(L_WARN "KRT: Netlink strict checking failed, will scan all tables at once");
+ krt_use_shared_scan();
+ }
}
static void
@@ -256,11 +225,13 @@ nl_request_dump_addr(int af)
}
static void
-nl_request_dump_route(int af)
+nl_request_dump_route(int af, int table_id)
{
struct {
struct nlmsghdr nh;
struct rtmsg rtm;
+ struct rtattr rta;
+ u32 table_id;
} req = {
.nh.nlmsg_type = RTM_GETROUTE,
.nh.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)),
@@ -269,7 +240,17 @@ nl_request_dump_route(int af)
.rtm.rtm_family = af,
};
- send(nl_scan.fd, &req, sizeof(req), 0);
+ if (table_id < 256)
+ req.rtm.rtm_table = table_id;
+ else
+ {
+ req.rta.rta_type = RTA_TABLE;
+ req.rta.rta_len = RTA_LENGTH(4);
+ req.table_id = table_id;
+ req.nh.nlmsg_len = NLMSG_ALIGN(req.nh.nlmsg_len) + req.rta.rta_len;
+ }
+
+ send(nl_scan.fd, &req, req.nh.nlmsg_len, 0);
nl_scan.last_hdr = NULL;
}
@@ -1325,7 +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;
@@ -1407,15 +1388,17 @@ 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);
@@ -1438,13 +1421,12 @@ 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
{
@@ -1470,82 +1452,53 @@ 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)
+nl_allow_replace(struct krt_proto *p, rte *new)
{
- 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);
+ /*
+ * 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.
+ *
+ * For IPv6, the NL_OP_REPLACE is still broken even in Linux 4.19 LTS
+ * (although it seems to be fixed in Linux 5.10 LTS) for sequence:
+ *
+ * ip route add 2001:db8::/32 via fe80::1 dev eth0
+ * ip route replace 2001:db8::/32 dev eth0
+ *
+ * (it ends with two routes instead of replacing the first by the second one)
+ *
+ * Replacing with direct and special type (e.g. unreachable) routes does not
+ * work, but replacing with regular routes work reliably
+ */
- return err;
-}
+ if (krt_ipv4(p))
+ return 1;
-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));
+ rta *a = new->attrs;
+ return (a->dest == RTD_UNICAST) && ipa_nonzero(a->nh.gw);
}
-
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 && nl_allow_replace(p, 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)
@@ -1557,71 +1510,6 @@ 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, s->proto->p.main_source);
- e->net = s->net;
-
- ea_list *ea = alloca(sizeof(ea_list) + 2 * sizeof(eattr));
- *ea = (ea_list) { .count = 2, .next = e->attrs->eattrs };
- e->attrs->eattrs = ea;
-
- ea->attrs[0] = (eattr) {
- .id = EA_KRT_SOURCE,
- .type = EAF_TYPE_INT,
- .u.data = s->krt_proto,
- };
- ea->attrs[1] = (eattr) {
- .id = EA_KRT_METRIC,
- .type = EAF_TYPE_INT,
- .u.data = s->krt_metric,
- };
-
- if (s->scan)
- krt_got_route(s->proto, e, s->krt_src);
- else
- krt_got_route_async(s->proto, e, s->new, s->krt_src);
-
- 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)
@@ -1759,13 +1647,29 @@ 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->source = RTS_INHERIT;
ra->scope = SCOPE_UNIVERSE;
+ {
+ ea_list *ea = lp_alloc(s->pool, sizeof(ea_list) + 2 * sizeof(eattr));
+ *ea = (ea_list) { .flags = EALF_SORTED, .count = 2 };
+ ea->next = ra->eattrs;
+ ra->eattrs = ea;
+
+ ea->attrs[0] = (eattr) {
+ .id = EA_KRT_SOURCE,
+ .type = EAF_TYPE_INT,
+ .u.data = i->rtm_protocol
+ };
+
+ ea->attrs[1] = (eattr) {
+ .id = EA_KRT_METRIC,
+ .type = EAF_TYPE_INT,
+ .u.data = priority,
+ };
+ }
+
if (a[RTA_FLOW])
s->rta_flow = rta_get_u32(a[RTA_FLOW]);
else
@@ -1942,60 +1846,40 @@ 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, p->p.main_source);
+ e->net = net;
- 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, krt_src);
else
- {
- /* Merge next hops with the stored route */
- rta *oa = s->attrs;
+ krt_got_route_async(p, e, new, krt_src);
- struct nexthop *nhs = &oa->nh;
- nexthop_insert(&nhs, &ra->nh);
-
- /* 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 UNUSED) /* CONFIG_ALL_TABLES_AT_ONCE => p is NULL */
+krt_do_scan(struct krt_proto *p)
{
- struct nlmsghdr *h;
- struct nl_parse_state s;
+ struct nl_parse_state s = {
+ .proto = p,
+ .pool = nl_linpool,
+ .scan = 1,
+ };
+
+ /* Table-specific scan or shared scan */
+ if (p)
+ nl_request_dump_route(p->af, krt_table_id(p));
+ else
+ nl_request_dump_route(AF_UNSPEC, 0);
- nl_parse_begin(&s, 1);
- nl_request_dump_route(AF_UNSPEC);
+ struct nlmsghdr *h;
while (h = nl_get_scan())
+ {
if (h->nlmsg_type == RTM_NEWROUTE || h->nlmsg_type == RTM_DELROUTE)
nl_parse_route(&s, h);
else
log(L_DEBUG "nl_scan_fire: Unknown packet received (type=%d)", h->nlmsg_type);
- nl_parse_end(&s);
+ }
}
/*
@@ -2010,16 +1894,18 @@ 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:
diff --git a/sysdep/unix/krt.c b/sysdep/unix/krt.c
index be547a93..c4a3a4a8 100644
--- a/sysdep/unix/krt.c
+++ b/sysdep/unix/krt.c
@@ -785,18 +785,17 @@ krt_got_route_async(struct krt_proto *p, rte *e, int new, s8 src)
rte_free(e);
}
+
/*
* Periodic scanning
*/
-
-#ifdef CONFIG_ALL_TABLES_AT_ONCE
-
-static timer *krt_scan_timer;
-static int krt_scan_count;
+static timer *krt_scan_all_timer;
+static int krt_scan_all_count;
+static _Bool krt_scan_all_tables;
static void
-krt_scan(timer *t UNUSED)
+krt_scan_all(timer *t UNUSED)
{
struct krt_proto *p;
node *n;
@@ -817,35 +816,42 @@ krt_scan(timer *t UNUSED)
}
static void
-krt_scan_timer_start(struct krt_proto *p)
+krt_scan_all_timer_start(struct krt_proto *p)
{
- if (!krt_scan_count)
- krt_scan_timer = tm_new_init(krt_pool, krt_scan, NULL, KRT_CF->scan_time, 0);
+ if (!krt_scan_all_count)
+ krt_scan_all_timer = tm_new_init(krt_pool, krt_scan_all, NULL, KRT_CF->scan_time, 0);
- krt_scan_count++;
+ krt_scan_all_count++;
- tm_start(krt_scan_timer, 1 S);
+ tm_start(krt_scan_all_timer, 1 S);
}
static void
-krt_scan_timer_stop(struct krt_proto *p UNUSED)
+krt_scan_all_timer_stop(void)
{
- krt_scan_count--;
+ ASSERT(krt_scan_all_count > 0);
+
+ krt_scan_all_count--;
- if (!krt_scan_count)
+ if (!krt_scan_all_count)
{
- rfree(krt_scan_timer);
- krt_scan_timer = NULL;
+ rfree(krt_scan_all_timer);
+ krt_scan_all_timer = NULL;
}
}
static void
-krt_scan_timer_kick(struct krt_proto *p UNUSED)
+krt_scan_all_timer_kick(void)
{
- tm_start(krt_scan_timer, 0);
+ tm_start(krt_scan_all_timer, 0);
+}
+
+void
+krt_use_shared_scan(void)
+{
+ krt_scan_all_tables = 1;
}
-#else
static void
krt_scan(timer *t)
@@ -863,26 +869,33 @@ krt_scan(timer *t)
static void
krt_scan_timer_start(struct krt_proto *p)
{
- p->scan_timer = tm_new_init(p->p.pool, krt_scan, p, KRT_CF->scan_time, 0);
- tm_start(p->scan_timer, 1 S);
+ if (krt_scan_all_tables)
+ krt_scan_all_timer_start(p);
+ else
+ {
+ p->scan_timer = tm_new_init(p->p.pool, krt_scan, p, KRT_CF->scan_time, 0);
+ tm_start(p->scan_timer, 1 S);
+ }
}
static void
krt_scan_timer_stop(struct krt_proto *p)
{
- tm_stop(p->scan_timer);
+ if (krt_scan_all_tables)
+ krt_scan_all_timer_stop();
+ else
+ tm_stop(p->scan_timer);
}
static void
krt_scan_timer_kick(struct krt_proto *p)
{
- tm_start(p->scan_timer, 0);
+ if (krt_scan_all_tables)
+ krt_scan_all_timer_kick();
+ else
+ tm_start(p->scan_timer, 0);
}
-#endif
-
-
-
/*
* Updates
@@ -992,11 +1005,6 @@ krt_postconfig(struct proto_config *CF)
if (! proto_cf_main_channel(CF))
cf_error("Channel not specified");
-#ifdef CONFIG_ALL_TABLES_AT_ONCE
- if (krt_cf->scan_time != cf->scan_time)
- cf_error("All kernel syncers must use the same table scan interval");
-#endif
-
struct channel_config *cc = proto_cf_main_channel(CF);
struct rtable_config *tab = cc->table;
if (tab->krt_attached)
diff --git a/sysdep/unix/krt.h b/sysdep/unix/krt.h
index 20858cd7..18a206e6 100644
--- a/sysdep/unix/krt.h
+++ b/sysdep/unix/krt.h
@@ -55,10 +55,7 @@ struct krt_proto {
struct rtable *krt_table; /* Internal table of inherited routes */
#endif
-#ifndef CONFIG_ALL_TABLES_AT_ONCE
timer *scan_timer;
-#endif
-
struct bmap sync_map; /* Keeps track which exported routes were successfully written to kernel */
struct bmap seen_map; /* Routes seen during last periodic scan */
node krt_node; /* Node in krt_proto_list */
@@ -79,6 +76,7 @@ extern pool *krt_pool;
struct proto_config * kif_init_config(int class);
void kif_request_scan(void);
+void krt_use_shared_scan(void);
void krt_got_route(struct krt_proto *p, struct rte *e, s8 src);
void krt_got_route_async(struct krt_proto *p, struct rte *e, int new, s8 src);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 00:33:45 +0000