Initial support for bonding (link aggrigation) in rc.inet1.

The bonding code introduces three new variables for use in rc.inet1.conf:
    BONDNICS[x]=""
    BONDMODE[x]=""
    BONDOPTS[x]=""

The BONDNICS variable takes a list of interfaces which should be slaved to
the bond.
BONDMODE sets the mode of the bond.  Useful options are 'balance-rr',
'active-backup' and '802.3ad'.  A full list of options can be found in
/usr/src/linux/Documentation/networking/bonding.txt and README.bonding.
BONDOPTS are a pipe (|) separated list of options to apply to the bond after
the interfaces have been added.  Useful options are 'primary' (which is
required when BONDMODE is 'active-backup', 'xmit_hash_policy' (which can be
used with 'balance-rr' to choose the hash policy, 'lacp_rate' (which should
be used with '802.3ad' mode), and 'miimon' (which should be used with all
modes)  See the kernel source documentation or README.bonding for more info.

3 files changed, 72 insertions, 7 deletions

diff --git a/modprobe.d/bonding.conf b/modprobe.d/bonding.conf
new file mode 100644
index 0000000..20652c2
--- /dev/null
+++ b/modprobe.d/bonding.conf
@@ -0,0 +1,2 @@
+options bonding max_bonds=0
+options rtnl-link-bond max_bonds=0
diff --git a/rc.inet1 b/rc.inet1
index d8cbdfd..c19571f 100644
--- a/rc.inet1
+++ b/rc.inet1
@@ -175,6 +175,50 @@ br_close() {
   /sbin/ip link del ${IFNAME[$1]}
 }
 
+# Function to create a bond.
+bond_create() {
+  # Argument is 'i' - the position of this interface in the IFNAME array.
+  info_log "${IFNAME[$1]}: creating bond"
+  debug_log "/sbin/ip link add name ${IFNAME[$1]} type bond"
+  /sbin/ip link add name ${IFNAME[$1]} type bond
+  debug_log "/sbin/ip link set dev ${IFNAME[$1]} type bond mode ${BONDMODE[$1]}"
+  /sbin/ip link set dev ${IFNAME[$1]} type bond mode ${BONDMODE[$1]}
+  for BONDIF in ${BONDNICS[$1]}; do
+    debug_log "/sbin/ip link set dev $BONDIF down"
+    /sbin/ip link set dev $BONDIF down
+    debug_log "/sbin/ip address flush dev $BONDIF"
+    /sbin/ip address flush dev $BONDIF
+    debug_log "/sbin/ip link set $BONDIF master ${IFNAME[$1]}"
+    /sbin/ip link set $BONDIF master ${IFNAME[$1]}
+    debug_log "/sbin/ip link set dev $BONDIF up"
+    /sbin/ip link set dev $BONDIF up
+  done
+  while read -r -d \| BONDOPT; do
+    if [ -n "$BONDOPT" ]; then
+      debug_log "/sbin/ip link set dev ${IFNAME[$1]} type bond $BONDOPT"
+      /sbin/ip link set dev ${IFNAME[$1]} type bond $BONDOPT
+    fi
+  done <<<"${BONDOPTS[$1]}|"	# The | on the end is required.
+}
+
+# Function to destroy a bond.
+bond_destroy() {
+  # Argument is 'i' - the position of this interface in the IFNAME array.
+  info_log "${IFNAME[$1]}: destroying bond"
+  debug_log "/sbin/ip link set dev ${IFNAME[$1]} down"
+  /sbin/ip link set dev ${IFNAME[$1]} down
+  debug_log "/sbin/ip address flush dev ${IFNAME[$1]}"
+  /sbin/ip address flush dev ${IFNAME[$1]}
+  for BONDIF in ${BONDNICS[$1]}; do
+    debug_log "/sbin/ip link set $BONDIF nomaster"
+    /sbin/ip link set $BONDIF nomaster
+    debug_log "/sbin/ip link set dev $BONDIF down"
+    /sbin/ip link set dev $BONDIF down
+  done
+  debug_log "/sbin/ip link del name ${IFNAME[$1]} type bond"
+  /sbin/ip link del name ${IFNAME[$1]} type bond
+}
+
 # Function to bring up a network interface.  If the interface is
 # already up or does not yet exist (perhaps because the kernel driver
 # is not loaded yet), do nothing.
@@ -194,10 +238,12 @@ if_up() {
     return
   fi
   info_log "${1}: configuring interface"
-  # If the interface is a bridge, then create it first.
-  # If you need to set hardware addresses for the underlying interfaces,
-  # configure the interfaces with IPs of 0.0.0.0 and set the MAC address
-  # in the usual way.  Then, finally, define the bridge.
+  # If you need to set hardware addresses for the underlying interfaces in a
+  # bond or bridge, configure the interfaces with IPs of 0.0.0.0 and set the
+  # MAC address with HWADDR.  Then, finally, define the bond or bridge.
+  # If the interface is a bond, create it.
+  [ -n "${BONDNICS[$i]}" ] && bond_create $i
+  # If the interface is a bridge, create it.
   [ -n "${BRNICS[$i]}" ] && br_open $i
   if [ -e /sys/class/net/${1%%[:.]*} ]; then # interface exists
     if ! /sbin/ip address show scope global dev ${1} 2>/dev/null | grep -Ewq '(inet|inet6)' || \
@@ -460,9 +506,9 @@ if_down() {
       cat /proc/sys/net/ipv6/conf/default/accept_ra >/proc/sys/net/ipv6/conf/$1/accept_ra
     fi
     # If the interface is a bridge, then destroy it now:
-    if [ -n "${BRNICS[$i]}" ]; then
-      br_close $i
-    fi
+    [ -n "${BRNICS[$i]}" ] && br_close $i
+    # If the interface is a bond, then destroy it now.
+    [ -n "${BONDNICS[$i]}" ] && bond_destroy $i
     # Take down VLAN interface, if configured.
     if echo "${1}" | grep -Fq .; then
       info_log "${1}: destroying VLAN interface"
diff --git a/rc.inet1.conf b/rc.inet1.conf
index ce22cd3..e48f5c1 100644
--- a/rc.inet1.conf
+++ b/rc.inet1.conf
@@ -78,6 +78,23 @@ DEBUG_ETH_UP="no"
 
 # =============================================================================
 
+# Example of how to configure a bond (link aggrigation) interface.
+
+# IFNAME[0]="bond0"
+# BONDNICS[0]="eth0 eth1"
+# BONDMODE[0]="balance-rr"
+# BONDOPTS[0]="xmit_hash_policy layer2+3 | miimon 100"
+# IPADDR[0]="192.168.0.1"
+# NETMASK[0]="24"
+# IPALIASES[0]=""
+# USE_DHCP[0]=""
+# DHCP_HOSTNAME[0]=""
+# IP6ADDRS[0]=""
+# USE_SLAAC[0]=""
+# USE_DHCP6[0]=""
+
+# =============================================================================
+
 # Example of how to configure a VLAN interface.
 # The VLAN ID is taken from the full interface name, which is comprised of the
 # underlying interface name, a period (.) and then the VLAN ID.