ryantimwilson / rpms / systemd

Forked from rpms/systemd a month ago
Clone
803fb7
From 0dd3b68d80bd32ecc5db65d634072390dad581aa Mon Sep 17 00:00:00 2001
803fb7
From: Richard Maw <richard.maw@codethink.co.uk>
803fb7
Date: Thu, 12 Mar 2015 18:14:58 +0000
803fb7
Subject: [PATCH] networkd: Begin with serial number 1 for netlink requests
803fb7
803fb7
"Notifications are of informal nature and no reply is expected, therefore the
803fb7
sequence number is typically set to 0."[1]
803fb7
803fb7
If networkd is started soon after recent netlink activity, then there
803fb7
will be messages with sequence number 0 in the buffer.
803fb7
803fb7
The first thing networkd does is to request a dump of all the links. If
803fb7
it uses sequence number 0 for this, then it may confuse the dump request's
803fb7
response with that of a notification.
803fb7
803fb7
This will result in it failing to properly enumerate all the links,
803fb7
but more importantly, when it comes to enumerate all the addresses, it
803fb7
will still have the link dump in progress, so the address enumeration
803fb7
will fail with -EBUSY.
803fb7
803fb7
[1]: http://www.infradead.org/~tgr/libnl/doc/core.html#core_msg_types
803fb7
803fb7
[tomegun: sequence -> serial]
803fb7
803fb7
(cherry picked from commit d422e52a3523ad0955bec4f9fbed46e234d28590)
803fb7
---
803fb7
 src/libsystemd/sd-rtnl/sd-rtnl.c | 5 +++++
803fb7
 1 file changed, 5 insertions(+)
803fb7
803fb7
diff --git a/src/libsystemd/sd-rtnl/sd-rtnl.c b/src/libsystemd/sd-rtnl/sd-rtnl.c
803fb7
index ae49c77e0..7cdcc5d96 100644
803fb7
--- a/src/libsystemd/sd-rtnl/sd-rtnl.c
803fb7
+++ b/src/libsystemd/sd-rtnl/sd-rtnl.c
803fb7
@@ -61,6 +61,11 @@ static int sd_rtnl_new(sd_rtnl **ret) {
803fb7
                             sizeof(struct nlmsghdr), sizeof(uint8_t)))
803fb7
                 return -ENOMEM;
803fb7
 
803fb7
+        /* Change notification responses have sequence 0, so we must
803fb7
+         * start our request sequence numbers at 1, or we may confuse our
803fb7
+         * responses with notifications from the kernel */
803fb7
+        rtnl->serial = 1;
803fb7
+
803fb7
         *ret = rtnl;
803fb7
         rtnl = NULL;
803fb7