run.py: always create a bridge and run dhcp on the bridge

Signed-off-by: Reto Achermann <achreto@gmail.com>

Author: achreto

kernel/run.py

@@ -749,20 +749,26 @@ def configure_network(args):
         sudo[ip[['link', 'set', '{}'.format(tap), 'down']]](retcode=(0, 1))
         sudo[ip[['link', 'del', '{}'.format(tap)]]](retcode=(0, 1))
 
-    # Need to find out how to set default=True in case workers are >0 in `args`
-    if (not 'workers' in args) or ('workers' in args and args.workers <= 1):
-        sudo[tunctl[['-t', args.tap, '-u', user, '-g', group]]]()
-        sudo[ifconfig[args.tap, NETWORK_INFRA_IP]]()
-        sudo[ip[['link', 'set', args.tap, 'up']]](retcode=(0, 1))
-    else:
-        assert args.workers <= MAX_WORKERS, "Too many workers, can't configure network"
-        sudo[ip[['link', 'add', 'br0', 'type', 'bridge']]]()
-        sudo[ip[['addr', 'add', NETWORK_INFRA_IP, 'brd', '+', 'dev', 'br0']]]()
-        for _, ncfg in zip(range(0, args.workers), NETWORK_CONFIG):
-            sudo[tunctl[['-t', ncfg, '-u', user, '-g', group]]]()
-            sudo[ip[['link', 'set', ncfg, 'up']]](retcode=(0, 1))
-            sudo[brctl[['addif', 'br0', ncfg]]]()
-        sudo[ip[['link', 'set', 'br0', 'up']]](retcode=(0, 1))
+
+    # figure out how many workers we have
+    workers = 1
+    if 'workers' in args:
+        workers = args.workers
+
+    # create the bridge
+    sudo[ip[['link', 'add', 'br0', 'type', 'bridge']]]()
+    sudo[ip[['addr', 'add', NETWORK_INFRA_IP, 'brd', '+', 'dev', 'br0']]]()
+
+    # add a network interface for every worker there is
+    for _, ncfg in zip(range(0, workers), NETWORK_CONFIG):
+        sudo[tunctl[['-t', ncfg, '-u', user, '-g', group]]]()
+        sudo[ip[['link', 'set', ncfg, 'up']]](retcode=(0, 1))
+        sudo[brctl[['addif', 'br0', ncfg]]]()
+
+    # set the link up
+    sudo[ip[['link', 'set', 'br0', 'up']]](retcode=(0, 1))
+
+    sudo[brctl[['setageing', 'br0', 600]]]()
 
 
 def configure_dcm_scheduler(args):

kernel/testutils/src/helpers.rs

@@ -17,7 +17,7 @@ use crate::runner_args::RunnerArgs;
 ///
 /// # Depends on
 /// - `tests/dhcpd.conf`: config file contains match of MAC to IP
-pub const DHCP_ACK_MATCH: &'static str = "DHCPACK on 172.31.0.10 to 56:b4:44:e9:62:d0 via tap0";
+pub const DHCP_ACK_MATCH: &'static str = "DHCPACK on 172.31.0.10 to 56:b4:44:e9:62:d0 via br0";
 pub const DHCP_ACK_MATCH_NRK2: &'static str = "DHCPACK on 172.31.0.11 to 56:b4:44:e9:62:d1 via br0";
 
 /// Default shmem region size (in MB)
@@ -219,7 +219,7 @@ pub fn spawn_dcm(cfg: Option<DCMConfig>) -> Result<rexpect::session::PtySession>
 
 /// Spawns a DHCP server on our host using most common interface: tap0
 pub fn spawn_dhcpd() -> Result<rexpect::session::PtyReplSession> {
-    spawn_dhcpd_with_interface("tap0".to_string())
+    spawn_dhcpd_with_interface("br0".to_string())
 }
 
 /// Spawns a DHCP server on our host