From 80de03ccc994eb20120ef1271201a45b92aaa449 Mon Sep 17 00:00:00 2001
From: Nick Chambers <nchambers@securitea.app>
Date: Sat, 19 Jun 2021 23:31:40 -0500
Subject: [PATCH] Add support for configuration files

---
 rowbot | 260 +++++++++++++++++++++++++++++----------------------------
 1 file changed, 131 insertions(+), 129 deletions(-)

diff --git a/rowbot b/rowbot
index 3f2ab10..fe5c975 100755
--- a/rowbot
+++ b/rowbot
@@ -1,7 +1,36 @@
 #!/usr/bin/env bash
 
+###
+# switch toggler
+###
+
 shopt -s nullglob dotglob extglob
 
+###
+# utilities
+###
+
+parent() {
+  (( BASHPID == $$ ))
+}
+
+has() {
+  hash "$1" 2>/dev/null
+}
+
+die() {
+  local status=1
+
+  if (( $# > 1 )) && [[ $1 = -s ]]; then
+    status=$2
+    shift
+    shift
+  fi
+
+  error "$@"
+  exit "$status"
+}
+
 ###
 # logger
 ###
@@ -13,7 +42,7 @@ declare -A levels=(
 
 log() {
   if [[ -v LEVEL ]] && (( levels[$level] <= levels[$LEVEL] )); then
-    printf "%s: $1\n" "${LEVEL^^}" "${@:2}" >&"$log"
+    printf "%s: $1\n" "${LEVEL^^}" "${@:2}" >&"$log_fd"
   fi
 }
 
@@ -37,7 +66,7 @@ error() {
 # argument parser for parsing arguments
 ##
 
-original_args=("$0" "$@")
+original_args=( "$@" )
 declare -A opts
 
 while (( $# )); do
@@ -69,79 +98,118 @@ done
 # default config
 ##
 
-server=${opts[server]:-irc.libera.chat}
-tls=${opts[tls]:-no}
+server=irc.libera.chat port=6667 tls=no client_cert=
+nick=rowbot-dev ident=rowbot realname=rowbot chan=
+trigger=\` fact_root=. reload=no level=info log_fd=1 log=
+# shellcheck disable=SC2034
+sys_root=sysfacts owner=${USER:-uplime} dev=no
+
+###
+# apply custom config
+###
+
+for file do
+  if [[ -f $file ]]; then
+    # These files are provided dynamically at run-time.
+    # shellcheck disable=SC1090
+    . "$file" # ha, dot file
+  else
+    die 'could not locate config file %s' "$file"
+  fi
+done
+
+###
+# apply command line options
+###
+
+if [[ -v opts[tls] ]]; then
+  tls=${opts[tls]}
+fi
 
 if [[ $tls = yes ]]; then
-  if ! hash socat 2>/dev/null; then
-    printf 'please install socat to use tls with rowbot.\n' >&2
-    exit 1
-  fi
-
-  # false positive
+  # This is a false positive.
   # shellcheck disable=SC2102
-  if [[ -v opts[client-cert] ]]; then
+  if ! has socat; then
+    die "please install socat to use tls with rowbot."
+  elif [[ -v opts[client-cert] ]]; then
     client_cert=${opts[client-cert]}
   fi
 
-  port=${opts[port]:-6697}
-else
-  port=${opts[port]:-6667}
+  port=6697
 fi
 
-nick=${opts[nick]:-rowbot-dev}
-ident=${opts[ident]:-rowbot}
-realname=${opts[realname]:-rowbot}
-chan=${opts[chan]:-}
-trigger=${opts[trigger]:-\`}
-fact_root=${opts[fact-root]:-.}
-reload=${opts[reload]:-no}
-dev=${opts[dev]:-no}
-sysfacts_file=${opts[sysfacts]:-./sysfacts.txt}
+config=(
+  server port nick ident realname chan trigger
+  fact_root reload dev level log owner sys_root
+  reload
+)
 
-if [[ -v USER ]]; then
-  owner=${opts[owner]:-"$USER"}
-else
-  owner=${opts[owner]:-uplime}
-fi
+for opt in "${config[@]}"; do
+  declare -n config_var=$opt
+  cmd_arg=${opt//_/-}
 
-level=${opts[log-level]:-info}
+  if [[ -v opts[$cmd_arg] ]]; then
+    # This variable is only used for assignment.
+    # shellcheck disable=SC2034
+    config_var=${opts[$cmd_arg]}
+  fi
+done
 
-if [[ $reload = yes ]]; then
-  log=$LOG_FD
-elif [[ ${opts[log]} ]]; then
-  exec {log}>"${opts[log]}"
-else
-  log=1
+if [[ $log && $reload = no ]]; then
+  exec {log_fd}>"$log"
 fi
 
 ###
-# utilities
+# apply reloaded values
+###
+
+if [[ $reload = yes ]]; then
+  reload_vars=(
+    nick ident host level log log_fd alarm_pid tls_pid in_sock
+    out_sock sock_dir sys_root fact_root dev trigger registered
+    keep_trying desired_nick
+  )
+
+  for var in "${reload_vars[@]}"; do
+    env_var=${var^^}
+    declare -n reload_var=$var
+
+    if [[ -v $env_var ]]; then
+      # This variable is only used for assignment.
+      # shellcheck disable=SC2034
+      reload_var=${!env_var}
+    fi
+  done
+fi
+
+###
+# process management
 ###
 
 cleanup() {
-  debug "cleaning up rowbot"
+  debug "reaping rowbot's children"
 
-  if [[ -v tls_pid ]]; then
-    kill "$tls_pid"
-    rm -rf "$sock_dir"
+  if [[ -v alarm_pid ]]; then
+    debug "killing alarm process (%d) from %d" "$alarm_pid" "$BASHPID"
+    kill "$alarm_pid"
   fi
 
-  if [[ -v ping_pid ]]; then
-    debug "cleaning up alarm in %d" "$BASHPID"
-    kill "$ping_pid"
+  if [[ -v tls_pid ]]; then
+    debug "killing tls process (%d) from %d" "$tls_pid" "$BASHPID"
+    kill "$tls_pid"
+    rm -rf "$sock_dir"
   fi
 
   if [[ -v tls_pid || $tls = no ]]; then
     exec {in_sock}>&- {out_sock}>&-
 
-    if (( log != 1 )); then
-      exec {log}>&-
+    if (( log_fd != 1 )); then
+      exec {log_fd}>&-
     fi
   fi
 }
 
-if (( BASHPID == $$ )); then
+if parent; then
   trap cleanup EXIT
 fi
 
@@ -156,37 +224,6 @@ alarm-handler() {
 
 trap alarm-handler ALRM
 
-###
-# reload code
-###
-
-if [[ $reload = yes ]]; then
-  in_sock=$IN_SOCK out_sock=$OUT_SOCK
-  trigger=$TRIGGER dev=$DEV level=$LOG_LEVEL
-  registered=$REGISTERED
-
-  debug "doing a reload. pid is %d" "$BASHPID"
-
-  if [[ -v KEEP_TRYING ]]; then
-    keep_trying=$KEEP_TRYING desired_nick=$DESIRED
-  fi
-
-  if [[ $tls = yes ]]; then
-    sock_dir=$SOCK_DIR
-    tls_pid=$TLS_PID
-  fi
-
-  if [[ -v PING_PID ]]; then
-    ping_pid=$PING_PID
-  fi
-
-  nick=$NICK ident=$IDENT
-
-  if [[ -v HOST ]]; then
-    host=$HOST
-  fi
-fi
-
 ###
 # net code
 ###
@@ -195,10 +232,9 @@ if [[ $reload = no && $tls = yes ]]; then
   sock_dir=$(mktemp -d)
   mkfifo "$sock_dir"/rb{in,out}
 
-  if [[ -v client_cert ]]; then
+  if [[ $client_cert ]]; then
     if [[ ! -f $client_cert ]]; then
-      error "client certificate not found: %s" "$client_cert"
-      exit 1
+      die "client certificate not found: %s" "$client_cert"
     fi
 
     conn_args=OPENSSL:$server:$port,cert=$client_cert
@@ -208,8 +244,8 @@ if [[ $reload = no && $tls = yes ]]; then
 
   socat "$conn_args" - <"$sock_dir"/rbin >"$sock_dir"/rbout &
   tls_pid=$!
-  debug "created tls connection (pid %d)" "$tls_pid"
   exec {out_sock}>"$sock_dir"/rbin {in_sock}<"$sock_dir"/rbout
+  debug "created tls connection (pid %d)" "$tls_pid"
 elif [[ $reload = no ]]; then
   exec {sock}<>/dev/tcp/"$server"/"$port"
   in_sock=$sock out_sock=$sock
@@ -218,7 +254,7 @@ fi
 
 send() {
   local fmt
-  # As this is a printf wrapper, the format string is provided as an argument
+  # As this is a printf wrapper, the format string is provided as an argument.
   # shellcheck disable=SC2059
   printf -v fmt "$1" "${@:2}"
   printf '%s\r\n' "$fmt" >&"$out_sock"
@@ -306,7 +342,7 @@ on_001() {
     done
   } &
 
-  ping_pid=$!
+  alarm_pid=$!
   nick=${params[0]}
   registered=yes
   who "$nick" %%uht,42
@@ -330,11 +366,11 @@ on_005() {
   local param key value
 
   for param in "${params[@]:1:${#params[@]}-2}"; do
-    # This is a valid assignment, not a comparison
+    # This is a valid assignment, not a comparison.
     # shellcheck disable=SC1097
     IFS== read -r key value <<< "$param"
     # While isupport is unused, it's still there in case later code wants to
-    # use it
+    # use it.
     # shellcheck disable=SC2034
     isupport[$key]=$value
     debug "isupport: %s = %s" "$key" "$value"
@@ -647,29 +683,18 @@ hook_post_PRIVMSG_control_panel() {
       privmsg "$to" "joined ${words[1]}"
       ;;
     reload)
-      export IN_SOCK=$in_sock OUT_SOCK=$out_sock LOG_FD=$log DEV=$dev
-      export RELOAD_TO=$to TRIGGER=$trigger LOG_LEVEL=$level
-      export NICK=$nick IDENT=$ident REGISTERED=$registered
+      reload_vars=(
+        nick ident host level log log_fd alarm_pid tls_pid in_sock
+        out_sock sock_dir sys_root fact_root dev trigger registered
+        keep_trying desired_nick to
+      )
 
-      if [[ $keep_trying = yes ]]; then
-        export KEEP_TRYING=yes DESIRED=$desired_nick
-      fi
-
-      if [[ -v host ]]; then
-        export HOST=$host
-      fi
-
-      if [[ $tls = yes ]]; then
-        export SOCK_DIR=$sock_dir
-        export TLS_PID=$tls_pid
-      fi
-
-      if [[ -v ping_pid ]]; then
-        export PING_PID=$ping_pid
-      fi
+      for env_var in "${reload_vars[@]}"; do
+        export "${env_var^^}"="${!env_var}"
+      done
 
       privmsg "$to" "reloading..."
-      exec "${original_args[@]}" --reload
+      exec "$0" --reload "${original_args[@]}"
       ;;
     level)
       level=${words[1]}
@@ -713,29 +738,6 @@ hook_post_PRIVMSG_control_panel() {
   fi
 }
 
-sysfacts=( )
-
-if [[ -f $sysfacts_file ]]; then
-  mapfile -t sysfacts < "$sysfacts_file"
-fi
-
-hook_post_PRIVMSG_sysfacts() {
-  local to=${params[0]} idx
-
-  if [[ ${params[0]:0:1} != \# ]]; then
-    to=$from
-  fi
-
-  if [[ ${words[0]} = "$trigger"sysfact ]]; then
-    if (( ${#sysfacts[@]} == 0 )); then
-      privmsg "$to" "sysfacts are not loaded :("
-    else
-      (( idx = RANDOM % ${#sysfacts[@]} ))
-      privmsg "$to" "sysfact #$(( idx + 1 )): ${sysfacts[$idx]}"
-    fi
-  fi
-}
-
 hook_post_433_alternick() {
   if [[ -z $desired_nick && $registered = no ]]; then
     desired_nick=${params[1]}
@@ -755,7 +757,7 @@ hook_post_NICK_alternick() {
 ###
 
 if [[ $reload = yes ]]; then
-  privmsg "$RELOAD_TO" done.
+  privmsg "$TO" done.
 else
   registered=no
   info "rowbot's pid is %d" "$BASHPID"