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125 lines
4.4 KiB
125 lines
4.4 KiB
#!/bin/sh |
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# -*- mode: shell-script; indent-tabs-mode: nil; sh-basic-offset: 4; -*- |
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# ex: ts=8 sw=4 sts=4 et filetype=sh |
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# |
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PATH=/usr/sbin:/usr/bin:/sbin:/bin |
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# File to start dhclient requests on different interfaces in parallel |
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. /lib/dracut-lib.sh |
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. /lib/net-lib.sh |
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netif=$1 |
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do_vlan=$2 |
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arg=$3 |
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# Run dhclient in parallel |
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do_dhclient() { |
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local _COUNT=0 |
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local _timeout=$(getargs rd.net.timeout.dhcp=) |
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local _DHCPRETRY=$(getargs rd.net.dhcp.retry=) |
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_DHCPRETRY=${_DHCPRETRY:-1} |
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while [ $_COUNT -lt $_DHCPRETRY ]; do |
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info "Starting dhcp for interface $netif" |
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dhclient $arg \ |
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${_timeout:+--timeout $_timeout} \ |
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-q \ |
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-1 \ |
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-cf /etc/dhclient.conf \ |
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-pf /tmp/dhclient.$netif.pid \ |
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-lf /tmp/dhclient.$netif.lease \ |
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$netif & |
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wait $! 2> /dev/null |
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# wait will return the return value of dhclient |
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retv=$? |
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# dhclient and hence wait returned success, 0. |
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if [ $retv -eq 0 ]; then |
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return 0 |
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fi |
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# If dhclient exited before wait was called, or it was killed by |
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# another thread for interface whose DHCP succeeded, then it will not |
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# find the process with that pid and return error code 127. In that |
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# case we need to check if /tmp/dhclient.$netif.lease exists. If it |
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# does, it means dhclient finished executing before wait was called, |
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# and it was successful (return 0). If /tmp/dhclient.$netif.lease |
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# does not exist, then it means dhclient was killed by another thread |
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# or it finished execution but failed dhcp on that interface. |
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if [ $retv -eq 127 ]; then |
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pid=$(cat /tmp/dhclient.$netif.pid) |
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info "PID $pid was not found by wait for $netif" |
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if [ -e /tmp/dhclient.$netif.lease ]; then |
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info "PID $pid not found but DHCP successful on $netif" |
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return 0 |
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fi |
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fi |
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_COUNT=$(($_COUNT + 1)) |
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[ $_COUNT -lt $_DHCPRETRY ] && sleep 1 |
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done |
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warn "dhcp for interface $netif failed" |
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# nuke those files since we failed; we might retry dhcp again if it's e.g. |
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# `ip=dhcp,dhcp6` and we check for the PID file earlier |
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rm -f /tmp/dhclient.$netif.{pid,lease} |
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return 1 |
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} |
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do_dhclient |
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ret=$? |
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# setup nameserver |
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for s in "$dns1" "$dns2" $(getargs nameserver); do |
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[ -n "$s" ] || continue |
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echo nameserver $s >> /tmp/net.$netif.resolv.conf |
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done |
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if [ $ret -eq 0 ]; then |
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> /tmp/net.${netif}.up |
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if [ -z "$do_vlan" ] && [ -e /sys/class/net/${netif}/address ]; then |
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> /tmp/net.$(cat /sys/class/net/${netif}/address).up |
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fi |
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# Check if DHCP also suceeded on another interface before this one. |
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# We will always use the first one on which DHCP succeeded, by using |
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# a commom file $IFNETFILE, to synchronize between threads. |
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# Consider the race condition in which multiple threads |
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# corresponding to different interfaces may try to read $IFNETFILE |
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# and find it does not exist; they may all end up thinking they are the |
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# first to succeed (hence more than one thread may end up writing to |
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# $IFNETFILE). To take care of this, instead of checking if $IFNETFILE |
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# exists to determine if we are the first, we create a symbolic link |
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# in $IFNETFILE, pointing to the interface name ($netif), thus storing |
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# the interface name in the link pointer. |
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# Creating a link will fail, if the link already exists, hence kernel |
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# will take care of allowing only first thread to create link, which |
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# takes care of the race condition for us. Subsequent threads will fail. |
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# Also, the link points to the interface name, which will tell us which |
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# interface succeeded. |
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if ln -s $netif $IFNETFILE 2> /dev/null; then |
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intf=$(readlink $IFNETFILE) |
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if [ -e /tmp/dhclient.$intf.lease ]; then |
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info "DHCP successful on interface $intf" |
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# Kill all existing dhclient calls for other interfaces, since we |
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# already got one successful interface |
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npid=$(cat /tmp/dhclient.$netif.pid) |
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pidlist=$(pgrep dhclient) |
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for pid in $pidlist; do |
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[ "$pid" -eq "$npid" ] && continue |
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kill -9 $pid > /dev/null 2>&1 |
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done |
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else |
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echo "ERROR! $IFNETFILE exists but /tmp/dhclient.$intf.lease does not exist!!!" |
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fi |
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else |
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info "DHCP success on $netif, and also on $intf" |
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exit 0 |
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fi |
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exit $ret |
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fi
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