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Diffstat (limited to 'dd-resume.in')
| -rw-r--r-- | dd-resume.in | 249 |
1 files changed, 249 insertions, 0 deletions
diff --git a/dd-resume.in b/dd-resume.in new file mode 100644 index 0000000..8f1d525 --- /dev/null +++ b/dd-resume.in @@ -0,0 +1,249 @@ +#!/bin/bash + +# dd-resume version #VERSION# + +usage() { + >&2 printf 'Usage: dd-resume [options]\n' + >&2 printf ' copy resumably with dd via network\n\n' + >&2 printf 'Options (all options are mandatory unless explicitely stated):\n' + >&2 printf ' --input $input-device name of input device\n' + >&2 printf ' --host $input-host name of input device'"'"'s host (target only)\n' + >&2 printf ' --log-file $log-file name of log file (target only)\n' + >&2 printf ' --output $output-device name of output device (target only)\n' + >&2 printf ' --port $remote-port port of target host (source only)\n' + >&2 printf ' --start $start-position start position for transfer (source only)\n' + >&2 printf ' --required print list of required programs and exit\n' + >&2 printf '#HELPTEXT# #\n' + [ -n "$1" ] && exit $1 + exit 1 +} + +dd_options='bs=2 count=2' +# bs=1M' +needed_programs='dd nc ss screen pgrep kill ssh' + +eval set -- "$( + getopt -o '' \ + --long input: \ + --long host: \ + --long log-file: \ + --long output: \ + --long port: \ + --long start: \ + --long required \ + --long help \ + --long version \ + -n "$(basename "$0")" \ + -- "$@" \ + || echo "usage" +)" + +while true; do + case $1 in + --input) + if [ -n "${input_device}" ]; then + >&2 printf 'cannot handle multiple input-devices\n\n' + usage + fi + shift + input_device="$1" + ;; + --host) + if [ -n "${host}" ]; then + >&2 printf 'cannot handle multiple hosts\n\n' + usage + fi + shift + host="$1" + ;; + --log-file) + if [ -n "${log_file}" ]; then + >&2 printf 'cannot handle multiple log files\n\n' + usage + fi + shift + log_file="$1" + ;; + --output) + if [ -n "${output_device}" ]; then + >&2 printf 'cannot handle multiple output devices\n\n' + usage + fi + shift + output_device="$1" + ;; + --port) + if [ -n "${remote_port}" ]; then + >&2 printf 'cannot handle multiple ports\n\n' + usage + fi + shift + remote_port="$1" + ;; + --start) + if [ -n "${start}" ]; then + >&2 printf 'cannot handle multiple starts\n\n' + usage + fi + shift + start="$1" + ;; + --required) + printf '%s\n' ${needed_programs} + exit 0 + ;; + --help) + usage 0 + ;; + --version) + >&2 printf '%s\n' '#VERSION#' + exit 0 + ;; + --) + shift + break + ;; + *) + >&2 printf 'oops, option "%s" is unkknown\n' "$1" + exit 1 + esac + shift +done + +if [ $# -ne 0 ]; then + >&2 printf 'too many arguments\n\n' + usage +fi + +for needed in ${needed_programs}; do + if ! which "${needed}" >/dev/null; then + >&2 printf 'please install required program %s\n' "${needed}" + exit 1 + fi +done + +if [ -z "${input_device}" ]; then + >&2 printf 'no input device specified\n\n' + usage +fi + +if [ -n "${host}" ]; then + # was run on the receiver side + + if [ -z "${log_file}" ] || \ + [ -z "${output_device}" ] || \ + [ -n "${remote_port}" ] || \ + [ -n "${start}" ]; then + >&2 printf 'conflicting options\n\n' + usage + fi + + if [ ! -w "${log_file%/*}" ] && [ ! -w "${log_file}" ]; then + >&2 printf 'cannot write/create log-file %s\n\n' "${log_file}" + usage + fi + + if [ ! -w "${output_device}" ]; then + >&2 printf 'cannot write to output device %s\n\n' "${output_device}" + usage + fi + + start=0 + if [ -f "${log_file}" ]; then + start=$( + sed -n ' + 1 { + s/^start: // + p + q + } + ' "${log_file}" + ) + copied=$( + sed ' + s/^\([0-9]\+\)+0 records out$/\1/ + t + d + ' "${log_file}" | \ + sort -n | \ + tail -n1 + ) + if [ -n "${copied}" ]; then + start=$((start+copied)) + fi + fi + + previously_running=$( + pgrep -x 'dd|nc' + ) + + printf 'start: %s\n' "${start}" > \ + "${log_file}" + + screen -d -m bash -c ' + set +o pipefail + nc -l -c | \ + dd of="'"${output_device}"'" '"${dd_options}"' seek='"${start}"' 2>>"'"${log_file}"'" >/dev/null + printf '"'"'\nwrite-pipe-exit: %s\n'"'"' $? >>"'"${log_file}"'" + ' + + for i in {1..20}; do + if [ -n "${port}" ]; then + break + elif [ ${i} -gt 1 ]; then + sleep 0.1 + fi + nc_pid=$( + pgrep -x nc | \ + grep -vxF "$(printf '%s\n' "${previously_running}")" + ) + dd_pid=$( + pgrep -x dd | \ + grep -vxF "$(printf '%s\n' "${previously_running}")" + ) + port=$( + ss -nlp | \ + grep -F ",pid=${nc_pid}," | \ + awk '{print $5}' | \ + sed 's/^.*://' + ) + done + if [ -z "${port}" ]; then + >&2 printf 'could not determine listening port\n' + exit 1 + fi + screen -d -m bash -c ' + while kill -SIGUSR1 '"${dd_pid}"'; do + sleep 1 + done + ' + + ssh "${host}" "$0 --input ${input_device} --start ${start} --port ${port}" + printf '\nssh-exit: %s\n' $? >>"${log_file}" + +else + # was run on the sender side + + if [ -n "${log_file}" ] || \ + [ -n "${output_device}" ] || \ + [ -z "${remote_port}" ] || \ + [ -z "${start}" ]; then + >&2 printf 'conflicting options\n\n' + usage + fi + + remote_ip="${SSH_CLIENT%% *}" + if [ -z "${remote_ip}" ]; then + >&2 printf 'cannot obtain remote ip\n' + exit 1 + fi + if [ ! -r "${input_device}" ]; then + >&2 printf 'cannot read from %s\n\n' "${input_device}" + usage + fi + set +o pipefail + dd if="${input_device}" ${dd_options} skip="${start}" 2>/dev/null | \ + nc -cn "${remote_ip}" "${remote_port}" + exit $? + +fi |