#!/bin/bash -e

## Copyright (c) 2005 David B. Harris <dbharris@eelf.ddts.net>
## Copyright (c) 2005,2016 Peter Palfrader <peter@palfrader.org>

## This text is released under the "three-clause BSD license".
## The full text of the license is available at the end of this file.

set -e
set -u

printf "\nrecvconf on %s processing:\n" "$(hostname -s)"

FILELIST=/etc/NOREPLY/recvconf.files
while [ "$#" -gt 0 ]; do
    case "$1" in
        -f)
            shift;
            FILELIST="$1"; shift
            ;;
        *)
            echo >&2 "Usage: $0 [-f <recvconf.files>"
            exit 1
            ;;
    esac
done

temptar=""
tempscript=""
tempoutput=""
tempdir=""

cleanup() {
    cd /
    if [ -n "$temptar" ]; then
        rm -f "$temptar"
    fi
    if [ -n "$tempscript" ]; then
        rm -f "$tempscript"
    fi
    if [ -n "$tempoutput" ]; then
        rm -f "$tempoutput"
    fi
    if [ -n "$tempdir" ]; then
        rm -rf "$tempdir"
    fi
}
trap 'cleanup' EXIT

temptar="$(mktemp)"
chmod 0600 "$temptar"

tempscript="$(mktemp)"
chmod 0600 "$tempscript"

tempdir="$(mktemp -d)"

# Read tarball from STDIN
gzip -dc > "$temptar"

cd "$tempdir"
tar xf "$temptar"

copy_and_runcommands() {

    local file perms user group precommand postcommand
    file="$1"; perms="$2"; user="$3"; group="$4"; precommand="$5"; postcommand="$6"

    if [ -f "$file" ]; then
        if [ -h "$file" ]; then # File should NOT be a symlink
            printf "\`%s' is a symlink, aborting.\n" "$file" >&2
            return 1
        fi

        if ! [ "$file" -nt "/$file" ]; then
            rm -f "$file"
            return 0
        fi

        if [ -n "$precommand" ]; then
            printf "Running precommand \`%s' for %s\n" "$precommand" "$file" >&2
            eval -- $precommand >&2
        fi

        if [ -n "$perms" ]; then
            chmod -- "$perms" "$file"
        else
            printf "Warning, no perms defined for \`%s', assuming 0640.\n" "$file" >&2
            chmod 0640 "$file"
        fi
        if [ -n "$user" ]; then
            chown -- "$user" "$file"
        else
            printf "Warning, no user defined for \`%s', assuming root.\n" "$file" >&2
            chown root "$file"
        fi
        if [ -n "$group" ]; then
            chgrp -- "$group" "$file"
        else
            printf "Warning, no group defined for \`%s', assuming root.\n" "$file" >&2
            chgrp root "$file"
        fi

        if [ ! -d "/$(dirname "$file")" ]; then
            printf "Directory \`%s' does not exist, aborting.\n" "$(dirname "$file")" >&2
            exit 1
        fi

        cp -a -- "$file" "/$(dirname "$file")" >&2
        ls -l "/$(dirname "$file")/$(basename "$file")" >&2

        if [ -n "$postcommand" ]; then
            if ! grep -F -- "$postcommand" "$tempscript" > /dev/null 2>&1; then
                printf "%s\n" "$postcommand" >> "$tempscript"
            fi
        fi

        rm -f -- "$file"
    fi
}

IN=0
linenum=0
nextfile=""
while read line; do
    linenum="$(($linenum + 1))"

    if printf "%s\n" "$line" | grep -E '^[[:space:]]*$' > /dev/null 2>&1; then
        ## This line is an empty line; skip it
        continue
    elif printf "%s" "$line" | grep -E '^[[:space:]]*#' > /dev/null 2>&1; then
        ## This line is a comment; skip it
        continue
    fi

    ## IN=0, so we're out of a stanza: better get a file declaration next
    if [ "$IN" = "0" ] && ! printf "%s" "$line" | grep -E '^[[:space:]]*file[[:space:]]' > /dev/null 2>&1; then
        printf "Error on line %s, file declaration expected. Got\n\t%s\n" "$linenum" "$line" >&2
        exit 1
    elif [ "$IN" = 0 ] && printf "%s" "$line" | grep -E '^[[:space:]]*file[[:space:]]' > /dev/null 2>&1; then
        ## Okay, we're just starting out; set $file and move on
        file="$(printf "%s" "$line" | sed -e 's/[[:space:]]*file[[:space:]]\+\([^[:space:]#]*\).*/\1/')"
        IN=1
        continue
    elif [ "$IN" = 1 ] && printf "%s" "$line" | grep -E '^[[:space:]]*file[[:space:]]' > /dev/null 2>&1; then
        ## Okay, not only are we at a file declaration, but this isn't our first one. Run the commands to process
        ## the file, then set a $file to the new value and continue parsing.
        [ -n "$file" ] && copy_and_runcommands "$file" "$perms" "$user" "$group" "$precommand" "$postcommand"
        file="$(printf "%s" "$line" | sed -e 's/[[:space:]]*file[[:space:]]\+\([^[:space:]#]*\).*/\1/')"
        perms=""; user=""; group=""; precommand=""; postcommand=""
        continue
    fi

    ## The last two if blocks weren't processed; thus this isn't a comment, a blank line, and we're in the middle of a stanza
    if printf "%s" "$line" | grep -E '^[[:space:]]*perms[[:space:]]' > /dev/null 2>&1; then
        perms="$(printf "%s" "$line" | sed -e 's/[[:space:]]*perms[[:space:]]\+\([^[:space:]#]*\).*/\1/')"
        continue
    elif printf "%s" "$line" | grep -E '^[[:space:]]*user[[:space:]]' > /dev/null 2>&1; then
        user="$(printf "%s" "$line" | sed -e 's/[[:space:]]*user[[:space:]]\+\([^[:space:]#]*\).*/\1/')"
        continue
    elif printf "%s" "$line" | grep -E '^[[:space:]]*group[[:space:]]' > /dev/null 2>&1; then
        group="$(printf "%s" "$line" | sed -e 's/[[:space:]]*group[[:space:]]\+\([^[:space:]#]*\).*/\1/')"
        continue
    elif printf "%s" "$line" | grep -E '^[[:space:]]*precommand[[:space:]]' > /dev/null 2>&1; then
        precommand="$(printf "%s" "$line" | sed -e 's/[[:space:]]*precommand[[:space:]]\+\([^[:space:]#]*\)/\1/')"
        continue
    elif printf "%s" "$line" | grep -E '^[[:space:]]*postcommand[[:space:]]' > /dev/null 2>&1; then
        postcommand="$(printf "%s" "$line" | sed -e 's/[[:space:]]*postcommand[[:space:]]\+\([^[:space:]#]*\)/\1/')"
        continue
    else
        printf "Unknown token at line %s:\n\t%s\n" "$linenum" "$line"
    fi

done < "$FILELIST"

## This is the last stanza and the above loop has set the variables, but hasn't yet processed the file
[ -n "$file" ] && copy_and_runcommands "$file" "$perms" "$user" "$group" "$precommand" "$postcommand"

if [ -s "$tempscript" ]; then
    tempoutput="$(mktemp)"
    ## Post-copying commands to be run, run them here. Only display output if they exit with $? > 0
    while read command; do
        printf "Running postcommand \`%s' on %s.\n" "$command" "$(hostname -s)" >&2
        if ! eval -- "(cd / && env -i $command)" > "$tempoutput" 2>&1; then
            printf "Error, postcommand \`%s' on %s failed. Output follows:\n" "$command" "$(hostname -s)" >&2
            cat -- "$tempoutput" >&2
            exit 1
        fi
    done < "$tempscript"
fi

# Check for any leftover files here; if there are any, exit with an error and print the list
if [ ! -z "$(find . -type f)" ]; then
    printf "The following files were not listed in $FILELIST:\n%s\n" "$(find . -type f)" >&2
    exit 1
fi

printf "recvconf on %s finished.\n" "$(hostname -s)"

## Redistribution and use in source and binary forms, with or without
## modification, are permitted provided that the following conditions are
## met:
## 
##     * Redistributions of source code must retain the above copyright
## notice, this list of conditions and the following disclaimer.
## 
##     * Redistributions in binary form must reproduce the above
## copyright notice, this list of conditions and the following disclaimer
## in the documentation and/or other materials provided with the
## distribution.
## 
##     * Neither the names of the copyright owners nor the names of its
## contributors may be used to endorse or promote products derived from
## this software without specific prior written permission.
## 
## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
## A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
## OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
## SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
## LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
## DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
## THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
## (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
## OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.