vswitchd: implement bond/hash unixctl

Our test case automation has a requirement to know which hash value a
given MAC address hashes to, in order to validate that balancing is
happening as expect etc.. Rather than attempt to reimplement the hash
algorithm used by vswitchd in python instead expose an appctl which
returns this information.

diff --git a/vswitchd/bridge.c b/vswitchd/bridge.c
index 48d02b3..6b7502b 100644 (file)
--- a/vswitchd/bridge.c
+++ b/vswitchd/bridge.c
@@ -2750,6 +2750,25 @@ bond_unixctl_disable_slave(struct unixctl_conn *conn, const char *args)
     enable_slave(conn, args, false);
 }
 
+static void
+bond_unixctl_hash(struct unixctl_conn *conn, const char *args)
+{
+       uint8_t mac[ETH_ADDR_LEN];
+       uint8_t hash;
+       char *hash_cstr;
+
+       if (sscanf(args, ETH_ADDR_SCAN_FMT, ETH_ADDR_SCAN_ARGS(mac))
+           == ETH_ADDR_SCAN_COUNT) {
+               hash = bond_hash(mac);
+
+               hash_cstr = xasprintf("%u", hash);
+               unixctl_command_reply(conn, 200, hash_cstr);
+               free(hash_cstr);
+       } else {
+               unixctl_command_reply(conn, 501, "invalid mac");
+       }
+}
+
 static void
 bond_init(void)
 {
@@ -2760,6 +2779,7 @@ bond_init(void)
                              bond_unixctl_set_active_slave);
     unixctl_command_register("bond/enable-slave", bond_unixctl_enable_slave);
     unixctl_command_register("bond/disable-slave", bond_unixctl_disable_slave);
+    unixctl_command_register("bond/hash", bond_unixctl_hash);
 }
 \f
 /* Port functions. */

diff --git a/vswitchd/ovs-vswitchd.8.in b/vswitchd/ovs-vswitchd.8.in
index 788e223..5c9a8c2 100644 (file)
--- a/vswitchd/ovs-vswitchd.8.in
+++ b/vswitchd/ovs-vswitchd.8.in
@@ -136,6 +136,8 @@ updelay (or downdelay).
 .IP
 This setting is not permanent: it persists only until the carrier
 status of \fIslave\fR changes.
+.IP "\fBbond/hash\fR \fImac\fR"
+Returns the hash value which would be used for \fImac\fR.
 .
 .so lib/vlog-unixctl.man
 .SH "SEE ALSO"