From: Richard Maw Date: Thu, 12 Mar 2015 18:14:58 +0000 (+0000) Subject: networkd: Begin with serial number 1 for netlink requests X-Git-Tag: v219.0~365 X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=d422e52a3523ad0955bec4f9fbed46e234d28590 networkd: Begin with serial number 1 for netlink requests "Notifications are of informal nature and no reply is expected, therefore the sequence number is typically set to 0."[1] If networkd is started soon after recent netlink activity, then there will be messages with sequence number 0 in the buffer. The first thing networkd does is to request a dump of all the links. If it uses sequence number 0 for this, then it may confuse the dump request's response with that of a notification. This will result in it failing to properly enumerate all the links, but more importantly, when it comes to enumerate all the addresses, it will still have the link dump in progress, so the address enumeration will fail with -EBUSY. [1]: http://www.infradead.org/~tgr/libnl/doc/core.html#core_msg_types [tomegun: sequence -> serial] --- diff --git a/src/libsystemd/sd-rtnl/sd-rtnl.c b/src/libsystemd/sd-rtnl/sd-rtnl.c index ae49c77e0..7cdcc5d96 100644 --- a/src/libsystemd/sd-rtnl/sd-rtnl.c +++ b/src/libsystemd/sd-rtnl/sd-rtnl.c @@ -61,6 +61,11 @@ static int sd_rtnl_new(sd_rtnl **ret) { sizeof(struct nlmsghdr), sizeof(uint8_t))) return -ENOMEM; + /* Change notification responses have sequence 0, so we must + * start our request sequence numbers at 1, or we may confuse our + * responses with notifications from the kernel */ + rtnl->serial = 1; + *ret = rtnl; rtnl = NULL;