kitty/shell-integration/ssh/bootstrap.sh
2022-03-07 19:41:18 +05:30

365 lines
12 KiB
Bash

#!/bin/sh
# Copyright (C) 2022 Kovid Goyal <kovid at kovidgoyal.net>
# Distributed under terms of the GPLv3 license.
saved_tty_settings=""
cleanup_on_bootstrap_exit() {
[ -n "$saved_tty_settings" ] && command stty "$saved_tty_settings" 2> /dev/null < /dev/tty
saved_tty_settings=""
}
die() { printf "\033[31m%s\033[m\n\r" "$*" > /dev/stderr; cleanup_on_bootstrap_exit; exit 1; }
python_detected="0"
detect_python() {
if [ python_detected = "1" ]; then
[ -n "$python" ] && return 0;
return 1;
fi
python_detected="1"
python=$(command -v python3)
if [ -z "$python" ]; then python=$(command -v python2); fi
if [ -z "$python" ]; then python=$(command -v python); fi
if [ -z "$python" -o ! -x "$python" ]; then python=""; return 1; fi
return 0
}
if command -v base64 > /dev/null 2> /dev/null; then
base64_encode() { command base64 | command tr -d \\n\\r; }
base64_decode() { command base64 -d; }
elif detect_python; then
pybase64() { command "$python" -c "import sys, base64; getattr(sys.stdout, 'buffer', sys.stdout).write(base64.standard_b64$1(getattr(sys.stdin, 'buffer', sys.stdin).read()))"; }
base64_encode() { pybase64 "encode"; }
base64_decode() { pybase64 "decode"; }
else
die "base64 executable not present on remote host, ssh kitten cannot function."
fi
init_tty() {
saved_tty_settings=$(command stty -g 2> /dev/null < /dev/tty)
tty_ok="n"
[ -n "$saved_tty_settings" ] && tty_ok="y"
if [ "$tty_ok" = "y" ]; then
command stty raw min 1 time 0 -echo 2> /dev/null < /dev/tty || die "stty failed to set raw mode"
return 0
fi
return 1
}
# try to use zsh's builtin sysread function for reading to TTY
# as it is superior to the POSIX variants. The builtin read function doesn't work
# as it hangs reading N bytes on macOS
tty_fd=-1
if builtin zmodload zsh/system 2> /dev/null; then
builtin sysopen -o cloexec -rwu tty_fd -- "$TTY" 2> /dev/null
[ $tty_fd = -1 ] && builtin sysopen -o cloexec -rwu tty_fd -- /dev/tty 2> /dev/null
fi
if [ $tty_fd -gt -1 ]; then
dcs_to_kitty() {
builtin local b64data
b64data=$(builtin printf "%s" "$2" | base64_encode)
builtin print -nu "$tty_fd" '\eP@kitty-'"${1}|${b64data//[[:space:]]}"'\e\\'
}
read_one_byte_from_tty() {
builtin sysread -s "1" -i "$tty_fd" n 2> /dev/null
return $?
}
read_n_bytes_from_tty() {
builtin let num_left=$1
while [ $num_left -gt 0 ]; do
builtin sysread -c num_read -s "$num_left" -i "$tty_fd" -o "1" 2> /dev/null || die "Failed to read $num_left bytes from TTY using sysread"
builtin let num_left=$num_left-$num_read
done
}
else
dcs_to_kitty() { printf "\033P@kitty-$1|%s\033\\" "$(printf "%s" "$2" | base64_encode)" > /dev/tty; }
read_one_byte_from_tty() {
# We need a way to read a single byte at a time and to read a specified number of bytes in one invocation.
# The options are head -c, read -N and dd
#
# read -N is not in POSIX and dash/posh dont implement it. Also bash seems to read beyond
# the specified number of bytes into an internal buffer.
#
# head -c reads beyond the specified number of bytes into an internal buffer on macOS
#
# POSIX dd works for one byte at a time but for reading X bytes it needs the GNU iflag=count_bytes
# extension, and is anyway unsafe as it can lead to corrupt output when the read syscall is interrupted.
n=$(command dd bs=1 count=1 2> /dev/null < /dev/tty)
return $?
}
read_n_bytes_from_tty() {
# using dd with bs=1 is very slow, so use head. On non GNU coreutils head
# does not limit itself to reading -c bytes only from the pipe so we can potentially lose
# some trailing data, for instance if the user starts typing. Cant be helped.
command head -c "$1" < /dev/tty
}
fi
debug() { dcs_to_kitty "print" "debug: $1"; }
echo_via_kitty() { dcs_to_kitty "echo" "$1"; }
hostname="$HOSTNAME"
[ -z "$hostname" ] && hostname="$(command hostname 2> /dev/null)"
[ -z "$hostname" ] && hostname="$(command hostnamectl hostname 2> /dev/null)"
[ -z "$hostname" ] && hostname="$(command uname -m 2> /dev/null)"
[ -z "$hostname" ] && hostname="_"
# ensure $HOME is set
[ -z "$HOME" ] && HOME=~
# ensure $USER is set
[ -z "$USER" ] && USER="$(command whoami 2> /dev/null)"
leading_data=""
login_cwd=""
init_tty && trap "cleanup_on_bootstrap_exit" EXIT
if [ "$tty_ok" = "y" ]; then
dcs_to_kitty "ssh" "id="REQUEST_ID":hostname="$hostname":pwfile="PASSWORD_FILENAME":user="$USER":pw="DATA_PASSWORD""
record_separator=$(printf "\036")
fi
mv_files_and_dirs() {
cwd="$PWD"
cd "$1"
command find . -type d -exec mkdir -p "$2/{}" ";"
command find . -type l -exec sh -c "tgt=\$(command readlink -n \"{}\"); command ln -sf \"\$tgt\" \"$2/{}\"; command rm -f \"{}\"" ";"
command find . -type f -exec mv "{}" "$2/{}" ";"
cd "$cwd"
}
compile_terminfo() {
# export TERMINFO
tname=".terminfo"
if [ -e "/usr/share/misc/terminfo.cdb" ]; then
# NetBSD requires this see https://github.com/kovidgoyal/kitty/issues/4622
tname=".terminfo.cdb"
fi
export TERMINFO="$HOME/$tname"
# compile terminfo for this system
if [ -x "$(command -v tic)" ]; then
tic_out=$(command tic -x -o "$1/$tname" "$1/.terminfo/kitty.terminfo" 2>&1)
rc=$?
if [ "$rc" != "0" ]; then die "$tic_out"; fi
fi
}
untar_and_read_env() {
# extract the tar file atomically, in the sense that any file from the
# tarfile is only put into place after it has been fully written to disk
tdir=$(command mktemp -d "$HOME/.kitty-ssh-kitten-untar-XXXXXXXXXXXX")
[ $? = 0 ] || die "Creating temp directory failed"
read_n_bytes_from_tty "$1" | base64_decode | command tar xpjf - -C "$tdir"
data_file="$tdir/data.sh"
[ -f "$data_file" ] && . "$data_file"
[ -z "$KITTY_SSH_KITTEN_DATA_DIR" ] && die "Failed to read SSH data from tty"
data_dir="$HOME/$KITTY_SSH_KITTEN_DATA_DIR"
unset KITTY_SSH_KITTEN_DATA_DIR
login_cwd="$KITTY_LOGIN_CWD"
unset KITTY_LOGIN_CWD
compile_terminfo "$tdir/home"
mv_files_and_dirs "$tdir/home" "$HOME"
[ -e "$tdir/root" ] && mv_files_and_dirs "$tdir/root" ""
command rm -rf "$tdir"
}
read_record() {
record=""
while :; do
read_one_byte_from_tty || die "Reading a byte from the TTY failed"
[ "$n" = "$record_separator" ] && break
record="$record$n"
done
printf "%s" "$record"
}
get_data() {
leading_data=$(read_record)
size=$(read_record)
case "$size" in
("!"*)
die "$size"
;;
esac
untar_and_read_env "$size"
}
if [ "$tty_ok" = "y" ]; then
# ask for the SSH data
get_data
cleanup_on_bootstrap_exit
if [ -n "$leading_data" ]; then
# clear current line as it might have things echoed on it from leading_data
# because we only turn off echo in this script whereas the leading bytes could
# have been sent before the script had a chance to run
printf "\r\033[K" > /dev/tty
fi
shell_integration_dir="$data_dir/shell-integration"
[ -f "$HOME/.terminfo/kitty.terminfo" ] || die "Incomplete extraction of ssh data"
fi
login_shell_is_ok() {
if [ -z "$login_shell" -o ! -x "$login_shell" ]; then return 1; fi
case "$login_shell" in
*sh) return 0;
esac
return 1
}
parse_passwd_record() {
printf "%s" "$(command grep -o '[^:]*$')"
}
using_getent() {
cmd=$(command -v getent)
if [ -n "$cmd" ]; then
output=$(command $cmd passwd $USER 2>/dev/null)
if [ $? = 0 ]; then
login_shell=$(echo $output | parse_passwd_record)
if login_shell_is_ok; then return 0; fi
fi
fi
return 1
}
using_id() {
cmd=$(command -v id)
if [ -n "$cmd" ]; then
output=$(command $cmd -P $USER 2>/dev/null)
if [ $? = 0 ]; then
login_shell=$(echo $output | parse_passwd_record)
if login_shell_is_ok; then return 0; fi
fi
fi
return 1
}
using_python() {
if detect_python; then
output=$(command "$python" -c "import pwd, os; print(pwd.getpwuid(os.geteuid()).pw_shell)")
if [ $? = 0 ]; then
login_shell=$output
if login_shell_is_ok; then return 0; fi
fi
fi
return 1
}
using_passwd() {
if [ -f "/etc/passwd" -a -r "/etc/passwd" ]; then
output=$(command grep "^$USER:" /etc/passwd 2>/dev/null)
if [ $? = 0 ]; then
login_shell=$(echo $output | parse_passwd_record)
if login_shell_is_ok; then return 0; fi
fi
fi
return 1
}
execute_with_python() {
if detect_python; then
exec "$python" -c "import os; os.execlp('$login_shell', '-' '$shell_name')"
fi
return 1
}
if [ -n "$KITTY_LOGIN_SHELL" ]; then
login_shell="$KITTY_LOGIN_SHELL"
unset KITTY_LOGIN_SHELL
else
using_getent || using_id || using_python || using_passwd || die "Could not detect login shell"
fi
shell_name=$(command basename $login_shell)
[ -n "$login_cwd" ] && cd "$login_cwd"
# If a command was passed to SSH execute it here
EXEC_CMD
if [ "$tty_ok" = "n" ]; then
if [ -z "$(command -v stty)" ]; then
printf "%s\n" "stty missing ssh kitten cannot function" > /dev/stderr
else
printf "%s\n" "stty failed ssh kitten cannot function" > /dev/stderr
fi
fi
exec_zsh_with_integration() {
zdotdir="$ZDOTDIR"
if [ -z "$zdotdir" ]; then
zdotdir=~
else
export KITTY_ORIG_ZDOTDIR="$zdotdir"
fi
# dont prevent zsh-newuser-install from running
if [ -f "$zdotdir/.zshrc" -o -f "$zdotdir/.zshenv" -o -f "$zdotdir/.zprofile" -o -f "$zdotdir/.zlogin" ]; then
export ZDOTDIR="$shell_integration_dir/zsh"
exec "$login_shell" "-l"
fi
unset KITTY_ORIG_ZDOTDIR # ensure this is not propagated
}
exec_fish_with_integration() {
if [ -z "$XDG_DATA_DIRS" ]; then
export XDG_DATA_DIRS="$shell_integration_dir"
else
export XDG_DATA_DIRS="$shell_integration_dir:$XDG_DATA_DIRS"
fi
export KITTY_FISH_XDG_DATA_DIR="$shell_integration_dir"
exec "$login_shell" "-l"
}
exec_bash_with_integration() {
export ENV="$shell_integration_dir/bash/kitty.bash"
export KITTY_BASH_INJECT="1"
if [ -z "$HISTFILE" ]; then
export HISTFILE="$HOME/.bash_history"
export KITTY_BASH_UNEXPORT_HISTFILE="1"
fi
exec "$login_shell" "--posix"
}
exec_with_shell_integration() {
case "$shell_name" in
"zsh")
exec_zsh_with_integration
;;
"fish")
exec_fish_with_integration
;;
"bash")
exec_bash_with_integration
;;
esac
}
# Used in the tests
TEST_SCRIPT
case "$KITTY_SHELL_INTEGRATION" in
("")
# only blanks or unset
unset KITTY_SHELL_INTEGRATION
;;
(*)
# not blank
q=$(printf "%s" "$KITTY_SHELL_INTEGRATION" | command grep '\bno-rc\b')
if [ -z "$q" ]; then
exec_with_shell_integration
# exec failed, unset
unset KITTY_SHELL_INTEGRATION
fi
;;
esac
# We need to pass the first argument to the executed program with a leading -
# to make sure the shell executes as a login shell. Note that not all shells
# support exec -a so we use the below to try to detect such shells
[ "$(exec -a echo echo OK 2> /dev/null)" = "OK" ] && exec -a "-$shell_name" $login_shell
execute_with_python
exec $login_shell "-l"