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authorMartin Mares <mj@ucw.cz>1999-03-04 19:36:18 +0100
committerMartin Mares <mj@ucw.cz>1999-03-04 19:36:18 +0100
commite16155ae4aaee5d9ba7b6940f8312b36707718e4 (patch)
treede2bbd930af01a8620871688e8ba36ba9d0111be
parent2253c9e239253d2094b4b1cabd97d296af885afb (diff)
downloadbird-e16155ae4aaee5d9ba7b6940f8312b36707718e4.tar
bird-e16155ae4aaee5d9ba7b6940f8312b36707718e4.zip
KRT: Implemented asynchronous route / interface state notifications
(via Netlink). Tweaked kernel synchronization rules a bit. Discovered locking bug in kernel Netlink :-) Future plans: Hunt all the bugs and solve all the FIXME's.
-rw-r--r--nest/route.h3
-rw-r--r--sysdep/linux/krt-scan.c1
-rw-r--r--sysdep/linux/netlink/netlink.c144
-rw-r--r--sysdep/unix/krt-set.c3
-rw-r--r--sysdep/unix/krt.c38
-rw-r--r--sysdep/unix/krt.h7
6 files changed, 178 insertions, 18 deletions
diff --git a/nest/route.h b/nest/route.h
index 243dcfa..2bcc2b5 100644
--- a/nest/route.h
+++ b/nest/route.h
@@ -140,6 +140,9 @@ typedef struct rte {
struct {
} bgp;
#endif
+ struct { /* Routes internally generated by krt sync */
+ int src; /* Alleged route source (see krt.h) */
+ } krt_sync;
} u;
} rte;
diff --git a/sysdep/linux/krt-scan.c b/sysdep/linux/krt-scan.c
index 4660682..9d19f71 100644
--- a/sysdep/linux/krt-scan.c
+++ b/sysdep/linux/krt-scan.c
@@ -127,6 +127,7 @@ krt_parse_entry(byte *ent, struct krt_proto *p)
e = rte_get_temp(&a);
e->net = net;
+ e->u.krt_sync.src = KRT_SRC_UNKNOWN;
krt_got_route(p, e);
}
diff --git a/sysdep/linux/netlink/netlink.c b/sysdep/linux/netlink/netlink.c
index e9b9886..64e3aa2 100644
--- a/sysdep/linux/netlink/netlink.c
+++ b/sysdep/linux/netlink/netlink.c
@@ -57,7 +57,7 @@ static int nl_sync_fd = -1; /* Unix socket for synchronous netlink actions */
static u32 nl_sync_seq; /* Sequence number of last request sent */
static byte *nl_rx_buffer; /* Receive buffer */
-static int nl_rx_size = 8192;
+#define NL_RX_SIZE 2048
static struct nlmsghdr *nl_last_hdr; /* Recently received packet */
static unsigned int nl_last_size;
@@ -71,7 +71,7 @@ nl_open(void)
if (nl_sync_fd < 0)
die("Unable to open rtnetlink socket: %m");
nl_sync_seq = now;
- nl_rx_buffer = xmalloc(nl_rx_size);
+ nl_rx_buffer = xmalloc(NL_RX_SIZE);
}
}
@@ -110,7 +110,7 @@ nl_get_reply(void)
{
if (!nl_last_hdr)
{
- struct iovec iov = { nl_rx_buffer, nl_rx_size };
+ struct iovec iov = { nl_rx_buffer, NL_RX_SIZE };
struct sockaddr_nl sa;
struct msghdr m = { (struct sockaddr *) &sa, sizeof(sa), &iov, 1, NULL, 0, 0 };
int x = recvmsg(nl_sync_fd, &m, 0);
@@ -456,6 +456,8 @@ nl_send_route(rte *e, int new)
} r;
struct nlmsghdr *reply;
+ DBG("nl_send_route(%I/%d,new=%d)\n", net->n.prefix, net->n.pxlen, new);
+
bzero(&r.h, sizeof(r.h));
bzero(&r.r, sizeof(r.r));
r.h.nlmsg_type = new ? RTM_NEWROUTE : RTM_DELROUTE;
@@ -499,6 +501,10 @@ nl_send_route(rte *e, int new)
void
krt_set_notify(struct proto *p, net *n, rte *new, rte *old)
{
+ if (old && old->attrs->source == RTS_DEVICE) /* Device routes are left to the kernel */
+ old = NULL;
+ if (new && new->attrs->source == RTS_DEVICE)
+ new = NULL;
if (old && new && old->attrs->tos == new->attrs->tos)
{
/* FIXME: Priorities should be identical as well, but we don't use them yet. */
@@ -507,7 +513,11 @@ krt_set_notify(struct proto *p, net *n, rte *new, rte *old)
else
{
if (old)
- nl_send_route(old, 0);
+ {
+ if (!old->attrs->iface || (old->attrs->iface->flags & IF_UP))
+ nl_send_route(old, 0);
+ /* else the kernel has already flushed it */
+ }
if (new)
nl_send_route(new, 1);
}
@@ -542,6 +552,7 @@ nl_parse_route(struct krt_proto *p, struct nlmsghdr *h, int scan)
rte *e;
net *net;
u32 oif;
+ int src;
if (!(i = nl_checkin(h, sizeof(*i))) || !nl_parse_attrs(RTM_RTA(i), a, sizeof(a)))
return;
@@ -559,7 +570,8 @@ nl_parse_route(struct krt_proto *p, struct nlmsghdr *h, int scan)
return;
if (i->rtm_tos != 0) /* FIXME: What about TOS? */
return;
- if (!new)
+
+ if (scan && !new)
{
DBG("KRT: Ignoring route deletion\n");
return;
@@ -579,6 +591,26 @@ nl_parse_route(struct krt_proto *p, struct nlmsghdr *h, int scan)
DBG("Got %I/%d, type=%d, oif=%d\n", dst, i->rtm_dst_len, i->rtm_type, oif);
+ switch (i->rtm_protocol)
+ {
+ case RTPROT_REDIRECT:
+ src = KRT_SRC_REDIRECT;
+ break;
+ case RTPROT_KERNEL:
+ DBG("Route originated in kernel, ignoring\n");
+ return;
+ case RTPROT_BIRD:
+ if (!scan)
+ {
+ DBG("Echo of our own route, ignoring\n");
+ return;
+ }
+ src = KRT_SRC_BIRD;
+ break;
+ default:
+ src = KRT_SRC_ALIEN;
+ }
+
net = net_get(&master_table, 0, dst, i->rtm_dst_len);
ra.proto = &p->p;
ra.source = RTS_INHERIT;
@@ -633,7 +665,11 @@ nl_parse_route(struct krt_proto *p, struct nlmsghdr *h, int scan)
}
e = rte_get_temp(&ra);
e->net = net;
- krt_got_route(p, e);
+ e->u.krt_sync.src = src;
+ if (scan)
+ krt_got_route(p, e);
+ else
+ krt_got_route_async(p, e, new);
}
void
@@ -654,12 +690,72 @@ krt_scan_fire(struct krt_proto *p)
*/
static sock *nl_async_sk; /* BIRD socket for asynchronous notifications */
+static byte *nl_async_rx_buffer; /* Receive buffer */
+
+static void
+nl_async_msg(struct krt_proto *p, struct nlmsghdr *h)
+{
+ switch (h->nlmsg_type)
+ {
+ case RTM_NEWROUTE:
+ case RTM_DELROUTE:
+ DBG("KRT: Received async route notification (%d)\n", h->nlmsg_type);
+ nl_parse_route(p, h, 0);
+ break;
+ case RTM_NEWLINK:
+ case RTM_DELLINK:
+ DBG("KRT: Received async link notification (%d)\n", h->nlmsg_type);
+ nl_parse_link(h, 0);
+ break;
+ case RTM_NEWADDR:
+ case RTM_DELADDR:
+ DBG("KRT: Received async address notification (%d)\n", h->nlmsg_type);
+ nl_parse_addr(h);
+ break;
+ default:
+ DBG("KRT: Received unknown async notification (%d)\n", h->nlmsg_type);
+ }
+}
static int
nl_async_hook(sock *sk, int size)
{
- DBG("nl_async_hook\n");
- return 0;
+ struct krt_proto *p = sk->data;
+ struct iovec iov = { nl_async_rx_buffer, NL_RX_SIZE };
+ struct sockaddr_nl sa;
+ struct msghdr m = { (struct sockaddr *) &sa, sizeof(sa), &iov, 1, NULL, 0, 0 };
+ struct nlmsghdr *h;
+ int x;
+ unsigned int len;
+
+ nl_last_hdr = NULL; /* Discard packets accidentally remaining in the rxbuf */
+ x = recvmsg(sk->fd, &m, 0);
+ if (x < 0)
+ {
+ if (errno != EWOULDBLOCK)
+ log(L_ERR "Netlink recvmsg: %m");
+ return 0;
+ }
+ if (sa.nl_pid) /* It isn't from the kernel */
+ {
+ DBG("Non-kernel packet\n");
+ return 1;
+ }
+ h = (void *) nl_async_rx_buffer;
+ len = x;
+ if (m.msg_flags & MSG_TRUNC)
+ {
+ log(L_WARN "Netlink got truncated asynchronous message");
+ return 1;
+ }
+ while (NLMSG_OK(h, len))
+ {
+ nl_async_msg(p, h);
+ h = NLMSG_NEXT(h, len);
+ }
+ if (len)
+ log(L_WARN "nl_async_hook: Found packet remnant of size %d", len);
+ return 1;
}
static void
@@ -667,21 +763,36 @@ nl_open_async(struct krt_proto *p)
{
sock *sk;
struct sockaddr_nl sa;
+ int fd;
DBG("KRT: Opening async netlink socket\n");
- sk = nl_async_sk = sk_new(p->p.pool);
- sk->type = SK_MAGIC;
- sk->rx_hook = nl_async_hook;
- sk->fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
- if (sk->fd < 0 || sk_open(sk))
- die("Unable to open secondary rtnetlink socket: %m");
+ fd = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+ if (fd < 0)
+ {
+ log(L_ERR "Unable to open secondary rtnetlink socket: %m");
+ return;
+ }
bzero(&sa, sizeof(sa));
sa.nl_family = AF_NETLINK;
sa.nl_groups = RTMGRP_LINK | RTMGRP_IPV4_IFADDR | RTMGRP_IPV4_ROUTE;
- if (bind(sk->fd, (struct sockaddr *) &sa, sizeof(sa)) < 0)
- die("Unable to bind secondary rtnetlink socket: %m");
+ if (bind(fd, (struct sockaddr *) &sa, sizeof(sa)) < 0)
+ {
+ log(L_ERR "Unable to bind secondary rtnetlink socket: %m");
+ return;
+ }
+
+ sk = nl_async_sk = sk_new(p->p.pool);
+ sk->type = SK_MAGIC;
+ sk->data = p;
+ sk->rx_hook = nl_async_hook;
+ sk->fd = fd;
+ if (sk_open(sk))
+ bug("Netlink: sk_open failed");
+
+ if (!nl_async_rx_buffer)
+ nl_async_rx_buffer = xmalloc(NL_RX_SIZE);
}
/*
@@ -692,6 +803,7 @@ void
krt_scan_preconfig(struct krt_config *x)
{
x->scan.async = 1;
+ /* FIXME: Use larger defaults for scanning times? */
}
void
diff --git a/sysdep/unix/krt-set.c b/sysdep/unix/krt-set.c
index dae01f4..2165255 100644
--- a/sysdep/unix/krt-set.c
+++ b/sysdep/unix/krt-set.c
@@ -43,7 +43,7 @@ krt_capable_op(rte *e)
rta *a = e->attrs;
#ifdef CONFIG_AUTO_ROUTES
- if (a->dest == RTD_ROUTER && a->source == RTS_DEVICE)
+ if (a->source == RTS_DEVICE)
return 0;
#endif
return krt_capable(e);
@@ -115,6 +115,7 @@ krt_add_route(rte *new)
void
krt_set_notify(struct proto *x, net *net, rte *new, rte *old)
{
+ /* FIXME: Fold remove/add route here */
if (old)
krt_remove_route(old);
if (new)
diff --git a/sysdep/unix/krt.c b/sysdep/unix/krt.c
index 5fbd52c..aa875cc 100644
--- a/sysdep/unix/krt.c
+++ b/sysdep/unix/krt.c
@@ -78,6 +78,7 @@ krt_got_route(struct krt_proto *p, rte *e)
{
rte *old;
net *net = e->net;
+ int src = e->u.krt_sync.src;
int verdict;
if (net->n.flags)
@@ -97,7 +98,7 @@ krt_got_route(struct krt_proto *p, rte *e)
else
verdict = KRF_UPDATE;
}
- else if (KRT_CF->learn && !net->routes)
+ else if (KRT_CF->learn && !net->routes && (src == KRT_SRC_ALIEN || src < 0))
verdict = KRF_LEARN;
else
verdict = KRF_DELETE;
@@ -188,6 +189,41 @@ krt_prune(struct krt_proto *p)
FIB_WALK_END;
}
+void
+krt_got_route_async(struct krt_proto *p, rte *e, int new)
+{
+ net *net = e->net;
+ rte *old = net->routes;
+ int src = e->u.krt_sync.src;
+
+ switch (src)
+ {
+ case KRT_SRC_BIRD:
+ ASSERT(0);
+ case KRT_SRC_REDIRECT:
+ DBG("It's a redirect, kill him! Kill! Kill!\n");
+ krt_set_notify(&p->p, net, NULL, e);
+ break;
+ default: /* Alien or unspecified */
+ if (KRT_CF->learn && new)
+ {
+ /*
+ * FIXME: This is limited to one inherited route per destination as we
+ * use single protocol for all inherited routes. Probably leave it
+ * as-is (and document it :)), because the correct solution is to
+ * multiple kernel tables anyway.
+ */
+ DBG("Learning\n");
+ rte_update(net, &p->p, e);
+ }
+ else
+ {
+ DBG("Discarding\n");
+ rte_update(net, &p->p, NULL);
+ }
+ }
+}
+
/*
* Periodic scanning
*/
diff --git a/sysdep/unix/krt.h b/sysdep/unix/krt.h
index 1c59799..02814c6 100644
--- a/sysdep/unix/krt.h
+++ b/sysdep/unix/krt.h
@@ -52,6 +52,13 @@ extern struct proto_config *cf_krt;
#define KRT_CF ((struct krt_config *)p->p.cf)
void krt_got_route(struct krt_proto *p, struct rte *e);
+void krt_got_route_async(struct krt_proto *p, struct rte *e, int new);
+
+/* Values for rte->u.krt_sync.src */
+#define KRT_SRC_UNKNOWN -1 /* Nobody knows */
+#define KRT_SRC_BIRD 0 /* Our route (not passed in async mode) */
+#define KRT_SRC_REDIRECT 1 /* Redirect route, delete it */
+#define KRT_SRC_ALIEN 2 /* Route installed by someone else */
/* krt-scan.c */