qemu

FORK: QEMU emulator
git clone https://git.neptards.moe/neptards/qemu.git
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common.nbd (2884B)


      1 #!/usr/bin/env bash
      2 # -*- shell-script-mode -*-
      3 #
      4 # Helpers for NBD server related config
      5 #
      6 # Copyright (C) 2018 Red Hat, Inc.
      7 #
      8 # This program is free software; you can redistribute it and/or modify
      9 # it under the terms of the GNU General Public License as published by
     10 # the Free Software Foundation; either version 2 of the License, or
     11 # (at your option) any later version.
     12 #
     13 # This program is distributed in the hope that it will be useful,
     14 # but WITHOUT ANY WARRANTY; without even the implied warranty of
     15 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     16 # GNU General Public License for more details.
     17 #
     18 # You should have received a copy of the GNU General Public License
     19 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
     20 #
     21 
     22 nbd_unix_socket="${SOCK_DIR}/qemu-nbd.sock"
     23 nbd_tcp_addr="127.0.0.1"
     24 nbd_pid_file="${TEST_DIR}/qemu-nbd.pid"
     25 nbd_stderr_fifo="${TEST_DIR}/qemu-nbd.fifo"
     26 
     27 # If bash version is >= 4.1, this will be overwritten by a dynamically
     28 # assigned file descriptor value.
     29 nbd_fifo_fd=10
     30 
     31 nbd_server_stop()
     32 {
     33     local NBD_PID
     34     if [ -f "$nbd_pid_file" ]; then
     35         read NBD_PID < "$nbd_pid_file"
     36         rm -f "$nbd_pid_file"
     37         if [ -n "$NBD_PID" ]; then
     38             kill "$NBD_PID"
     39         fi
     40     fi
     41     rm -f "$nbd_unix_socket" "$nbd_stderr_fifo"
     42 }
     43 
     44 nbd_server_start_unix_socket()
     45 {
     46     nbd_server_stop
     47     $QEMU_NBD -v -t -k "$nbd_unix_socket" --fork "$@"
     48 }
     49 
     50 nbd_server_start_tcp_socket()
     51 {
     52     nbd_server_stop
     53 
     54     mkfifo "$nbd_stderr_fifo"
     55     for ((port = 10809; port <= 10909; port++))
     56     do
     57         # Redirect stderr to FIFO, so we can later decide whether we
     58         # want to read it or to redirect it to our stderr, depending
     59         # on whether the command fails or not
     60         $QEMU_NBD -v -t -b $nbd_tcp_addr -p $port --fork "$@" \
     61             2> "$nbd_stderr_fifo" &
     62 
     63         # Taken from common.qemu
     64         if [[ "${BASH_VERSINFO[0]}" -ge "5" ||
     65             ("${BASH_VERSINFO[0]}" -ge "4" && "${BASH_VERSINFO[1]}" -ge "1") ]]
     66         then
     67             exec {nbd_fifo_fd}<"$nbd_stderr_fifo"
     68         else
     69             let _nbd_fifo_fd++
     70             eval "exec ${_nbd_fifo_fd}<'$nbd_stderr_fifo'"
     71         fi
     72         wait $!
     73 
     74         if test $? == 0
     75         then
     76             # Success, redirect qemu-nbd's stderr to our stderr
     77             nbd_tcp_port=$port
     78             (cat <&$nbd_fifo_fd >&2) &
     79             eval "exec $nbd_fifo_fd>&-"
     80             return
     81         fi
     82 
     83         # Failure, read the output
     84         output=$(cat <&$nbd_fifo_fd)
     85         eval "exec $nbd_fifo_fd>&-"
     86 
     87         if ! echo "$output" | grep -q "Address already in use"
     88         then
     89             # Unknown error, print it
     90             echo "$output" >&2
     91             rm -f "$nbd_stderr_fifo"
     92             exit 1
     93         fi
     94     done
     95 
     96     echo "Cannot find free TCP port for nbd in range 10809-10909"
     97     rm -f "$nbd_stderr_fifo"
     98     exit 1
     99 }