daandemeyer / rpms / systemd

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From 0dd3b68d80bd32ecc5db65d634072390dad581aa Mon Sep 17 00:00:00 2001
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From: Richard Maw <richard.maw@codethink.co.uk>
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Date: Thu, 12 Mar 2015 18:14:58 +0000
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Subject: [PATCH] networkd: Begin with serial number 1 for netlink requests
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"Notifications are of informal nature and no reply is expected, therefore the
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sequence number is typically set to 0."[1]
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If networkd is started soon after recent netlink activity, then there
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will be messages with sequence number 0 in the buffer.
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The first thing networkd does is to request a dump of all the links. If
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it uses sequence number 0 for this, then it may confuse the dump request's
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response with that of a notification.
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This will result in it failing to properly enumerate all the links,
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but more importantly, when it comes to enumerate all the addresses, it
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will still have the link dump in progress, so the address enumeration
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will fail with -EBUSY.
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[1]: http://www.infradead.org/~tgr/libnl/doc/core.html#core_msg_types
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[tomegun: sequence -> serial]
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(cherry picked from commit d422e52a3523ad0955bec4f9fbed46e234d28590)
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---
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 src/libsystemd/sd-rtnl/sd-rtnl.c | 5 +++++
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 1 file changed, 5 insertions(+)
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diff --git a/src/libsystemd/sd-rtnl/sd-rtnl.c b/src/libsystemd/sd-rtnl/sd-rtnl.c
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index ae49c77e01..7cdcc5d96a 100644
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--- a/src/libsystemd/sd-rtnl/sd-rtnl.c
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+++ b/src/libsystemd/sd-rtnl/sd-rtnl.c
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@@ -61,6 +61,11 @@ static int sd_rtnl_new(sd_rtnl **ret) {
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                             sizeof(struct nlmsghdr), sizeof(uint8_t)))
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                 return -ENOMEM;
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+        /* Change notification responses have sequence 0, so we must
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+         * start our request sequence numbers at 1, or we may confuse our
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+         * responses with notifications from the kernel */
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+        rtnl->serial = 1;
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+
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         *ret = rtnl;
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         rtnl = NULL;
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