[PATCHv2] teamd: add port_hwaddr_changed for ab runner

[Xin Long]

This patch to fix an events processing race issue when adding two ports
into one team dev with ab mode with same_all hwaddr policy:

team0 original hwaddr: 00:00:00:00:00:0a
port1 original hwaddr: 00:00:00:00:00:01
port2 original hwaddr: 00:00:00:00:00:02

There are two sockets in teamd: nl_cli.sock_event for ifinfo updates
and nl_sock_event for ports/options changes. During adding two ports,
the events on these two sockets could be:

nl_sock_event:
  [1] -- [2] --

[1]: port1 added event (added by enslaving port1)
[2]: port2 added event (added by enslaving port2)

nl_cli.sock_event:
  [a1] -- [b0] -- [c1] -- [d2] -- [e2] -- [f1] --

[a1]: port1 ifinfo event (added by setting port1's master)
[b0]: team0 ifinfo event (added by setting team0's hwaddr)
[c1]: port1 ifinfo event (added by set port1's hwaddr)
[d2]: port2 ifinfo event (added by set port2's master)
[e2]: port2 ifinfo event (added by set port2's hwaddr)
[f1]: port1 ifinfo event (added by set port1's hwaddr)

teamd can make sure the order for their processing is as above on the
same socket, but not between two sockets. So if these events processing
order is (monitoring team/ports' ifinfo, hwaddr, master):

[ 1]: team0->ifinfo = 00:00:00:00:00:0a
      team0->hwaddr = 00:00:00:00:00:01
      port1->hwaddr = 00:00:00:00:00:0a
[a1]: port1->ifinfo = 00:00:00:00:00:01
      port1->master = team0
[ 2]: port2->ifinfo = 00:00:00:00:00:02
      port2->hwaddr = 00:00:00:00:00:0a
     (team0->ifinfo is not updated, it's still 00:00:00:00:00:0a)
[b0]: team0->ifinfo = 00:00:00:00:00:01
      port1->hwaddr = 00:00:00:00:00:01
     (port2->master is not yet set, port2->hwaddr couldn't be updated)
[c1]: no changes
[d2]: port2->ifinfo = 00:00:00:00:00:0a
      port2->master = team0
     (too late !!!)
[e2]: no changes
[f1]: no changes

Then:
team0 final hwaddr: 00:00:00:00:00:01
port1 final hwaddr: 00:00:00:00:00:01
port2 final hwaddr: 00:00:00:00:00:0a <----- issue

This patch is to add port_hwaddr_changed for ab runner, in [e2] where
we set it's hwaddr with team0 (port2->hwaddr = 00:00:00:00:00:01) IF
port2->hwaddr != team0->ifinfo.

I think the same issue also exists in lacp and lb mode for which I will
fix them in another patches.

v1 -> v2:
  fix some typos in changelog and couple of style problems in codes

Reported-by: Jon Nikolakakis <jnikolak(a)redhat.com&gt;
Signed-off-by: Xin Long <lucien.xin(a)gmail.com&gt;
---
 teamd/teamd_runner_activebackup.c | 39 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/teamd/teamd_runner_activebackup.c b/teamd/teamd_runner_activebackup.c
index aec3a73..8a3447f 100644
--- a/teamd/teamd_runner_activebackup.c
+++ b/teamd/teamd_runner_activebackup.c
@@ -39,6 +39,8 @@ struct ab_hwaddr_policy {
 	const char *name;
 	int (*hwaddr_changed)(struct teamd_context *ctx,
 			      struct ab *ab);
+	int (*port_hwaddr_changed)(struct teamd_context *ctx, struct ab *ab,
+				   struct teamd_port *tdport);
 	int (*port_added)(struct teamd_context *ctx, struct ab *ab,
 			  struct teamd_port *tdport);
 	int (*active_set)(struct teamd_context *ctx, struct ab *ab,
@@ -95,6 +97,26 @@ static int ab_hwaddr_policy_same_all_hwaddr_changed(struct
teamd_context *ctx,
 	return 0;
 }
 
+static int
+ab_hwaddr_policy_same_all_port_hwaddr_changed(struct teamd_context *ctx,
+					      struct ab *ab,
+					      struct teamd_port *tdport)
+{
+	int err;
+
+	if (!memcmp(team_get_ifinfo_hwaddr(tdport->team_ifinfo),
+		    ctx->hwaddr, ctx->hwaddr_len))
+		return 0;
+
+	err = team_hwaddr_set(ctx->th, tdport->ifindex, ctx->hwaddr,
+			      ctx->hwaddr_len);
+	if (err)
+		teamd_log_err("%s: Failed to set port hardware address.",
+			      tdport->ifname);
+
+	return err;
+}
+
 static int ab_hwaddr_policy_same_all_port_added(struct teamd_context *ctx,
 						struct ab *ab,
 						struct teamd_port *tdport)
@@ -114,6 +136,7 @@ static int ab_hwaddr_policy_same_all_port_added(struct teamd_context
*ctx,
 static const struct ab_hwaddr_policy ab_hwaddr_policy_same_all = {
 	.name = "same_all",
 	.hwaddr_changed = ab_hwaddr_policy_same_all_hwaddr_changed,
+	.port_hwaddr_changed = ab_hwaddr_policy_same_all_port_hwaddr_changed,
 	.port_added = ab_hwaddr_policy_same_all_port_added,
 };
 
@@ -411,6 +434,21 @@ static int ab_event_watch_hwaddr_changed(struct teamd_context *ctx,
void *priv)
 	return 0;
 }
 
+static int ab_event_watch_port_hwaddr_changed(struct teamd_context *ctx,
+					      struct teamd_port *tdport,
+					      void *priv)
+{
+	struct ab *ab = priv;
+
+	if (!teamd_port_present(ctx, tdport))
+		return 0;
+
+	if (ab->hwaddr_policy->port_hwaddr_changed)
+		return ab->hwaddr_policy->port_hwaddr_changed(ctx, ab, tdport);
+
+	return 0;
+}
+
 static int ab_port_load_config(struct teamd_context *ctx,
 			       struct ab_port *ab_port)
 {
@@ -491,6 +529,7 @@ static int ab_event_watch_prio_option_changed(struct teamd_context
*ctx,
 
 static const struct teamd_event_watch_ops ab_event_watch_ops = {
 	.hwaddr_changed = ab_event_watch_hwaddr_changed,
+	.port_hwaddr_changed = ab_event_watch_port_hwaddr_changed,
 	.port_added = ab_event_watch_port_added,
 	.port_link_changed = ab_event_watch_port_link_changed,
 	.option_changed = ab_event_watch_prio_option_changed,
-- 
2.1.0