blob: 21570987c439b18cb50026bbbc0101e5a51a4f78 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
|
#!/bin/sh /etc/rc.common
# Copyright (C) 2006-2010 OpenWrt.org
# Copyright (C) 2006 Carlos Sobrinho
START=19
STOP=50
USE_PROCD=1
PROG=/usr/sbin/dropbear
NAME=dropbear
PIDCOUNT=0
extra_command "killclients" "Kill ${NAME} processes except servers and yourself"
# most of time real_stat() will be failing
# due to missing "stat" binary (by default)
real_stat() { env stat -L "$@" 2>/dev/null ; }
dumb_stat() { ls -Ldln "$1" | tr -s '\t ' ' ' ; }
stat_perm() { real_stat -c '%A' "$1" || dumb_stat "$1" | cut -d ' ' -f 1 ; }
stat_owner() { real_stat -c '%u' "$1" || dumb_stat "$1" | cut -d ' ' -f 3 ; }
_dropbearkey()
{
/usr/bin/dropbearkey "$@" </dev/null >/dev/null 2>&1
}
# $1 - file name (host key or config)
file_verify()
{
[ -f "$1" ] || return 1
# checking file ownership
[ "$(stat_owner "$1")" = "0" ] || {
chown 0 "$1"
[ "$(stat_owner "$1")" = "0" ] || return 2
}
# checking file permissions
[ "$(stat_perm "$1")" = "-rw-------" ] || {
chmod 0600 "$1"
[ "$(stat_perm "$1")" = "-rw-------" ] || return 3
}
# file is host key or not?
# if $2 is empty string - file is "host key"
# if $2 is non-empty string - file is "config"
[ -z "$2" ] || return 0
# checking file contents (finally)
[ -s "$1" ] || return 4
_dropbearkey -y -f "$1" || return 5
return 0
}
# $1 - file_verify() return code
file_errmsg()
{
case "$1" in
0) ;;
1) echo "file does not exist" ;;
2) echo "file has wrong owner (must be owned by root)" ;;
3) echo "file has wrong permissions (must not have group/other write bit)" ;;
4) echo "file has zero length" ;;
5) echo "file is not valid host key or not supported" ;;
*) echo "unknown error" ;;
esac
}
# $1 - config option
# $2 - host key file name
hk_config()
{
local x m
file_verify "$2" ; x=$?
if [ "$x" = 0 ] ; then
procd_append_param command -r "$2"
return
fi
m=$(file_errmsg "$x")
logger -s -t "${NAME}" -p daemon.warn \
"Option '$1', skipping '$2': $m"
}
# $1 - host key file name
hk_config__keyfile() { hk_config keyfile "$1" ; }
ktype_all='ed25519 ecdsa rsa'
hk_generate_as_needed()
{
local hk_cfg_dir kgen ktype kfile hk_tmp_dir
hk_cfg_dir='/etc/dropbear'
[ -d "${hk_cfg_dir}" ] || mkdir -p "${hk_cfg_dir}"
kgen=
for ktype in ${ktype_all} ; do
kfile="${hk_cfg_dir}/dropbear_${ktype}_host_key"
if file_verify "${kfile}" ; then continue ; fi
kgen="${kgen}${kgen:+ }${ktype}"
done
# all keys are sane?
[ -n "${kgen}" ] || return 0
hk_tmp_dir=$(mktemp -d)
# system in bad state?
[ -n "${hk_tmp_dir}" ] || return 1
chmod 0700 "${hk_tmp_dir}"
for ktype in ${kgen} ; do
kfile="${hk_tmp_dir}/dropbear_${ktype}_host_key"
if ! _dropbearkey -t ${ktype} -f "${kfile}" ; then
# unsupported key type
rm -f "${kfile}"
continue
fi
chmod 0600 "${kfile}"
done
kgen=
for ktype in ${ktype_all} ; do
kfile="${hk_tmp_dir}/dropbear_${ktype}_host_key"
[ -s "${kfile}" ] || continue
kgen="${kgen}${kgen:+ }${ktype}"
done
if [ -n "${kgen}" ] ; then
for ktype in ${kgen} ; do
kfile="${hk_tmp_dir}/dropbear_${ktype}_host_key"
[ -s "${kfile}" ] || continue
mv -f "${kfile}" "${hk_cfg_dir}/"
done
fi
rm -rf "${hk_tmp_dir}"
# cleanup empty files
for ktype in ${ktype_all} ; do
kfile="${hk_cfg_dir}/dropbear_${ktype}_host_key"
[ -s "${kfile}" ] || rm -f "${kfile}"
done
}
# $1 - list with whitespace-separated elements
normalize_list()
{
printf '%s' "$1" | tr -s ' \r\n\t' ' ' | sed -E 's/^ //;s/ $//'
}
warn_multiple_interfaces()
{
logger -t "${NAME}" -p daemon.warn \
"Option '$1' should specify SINGLE interface but instead it lists interfaces: $2"
logger -t "${NAME}" -p daemon.warn \
"Consider creating per-interface instances instead!"
}
validate_section_dropbear()
{
uci_load_validate dropbear dropbear "$1" "$2" \
'PasswordAuth:bool:1' \
'enable:bool:1' \
'DirectInterface:string' \
'Interface:string' \
'GatewayPorts:bool:0' \
'ForceCommand:string' \
'RootPasswordAuth:bool:1' \
'RootLogin:bool:1' \
'rsakeyfile:file' \
'keyfile:list(file)' \
'BannerFile:file' \
'Port:port:22' \
'SSHKeepAlive:uinteger:300' \
'IdleTimeout:uinteger:0' \
'MaxAuthTries:uinteger:3' \
'RecvWindowSize:uinteger:262144' \
'mdns:bool:1'
}
dropbear_instance()
{
[ "$2" = 0 ] || {
echo "validation failed"
return 1
}
[ "${enable}" = "1" ] || return 1
local iface ndev ipaddrs
# 'DirectInterface' should specify single interface
# but end users may misinterpret this setting
DirectInterface=$(normalize_list "${DirectInterface}")
# 'Interface' should specify single interface
# but end users are often misinterpret this setting
Interface=$(normalize_list "${Interface}")
if [ -n "${Interface}" ] ; then
if [ -n "${DirectInterface}" ] ; then
logger -t "${NAME}" -p daemon.warn \
"Option 'DirectInterface' takes precedence over 'Interface'"
else
logger -t "${NAME}" -p daemon.info \
"Option 'Interface' binds to address(es) but not to interface"
logger -t "${NAME}" -p daemon.info \
"Consider using option 'DirectInterface' to bind directly to interface"
fi
fi
# handle 'DirectInterface'
iface=$(echo "${DirectInterface}" | awk '{print $1}')
case "${DirectInterface}" in
*\ *)
warn_multiple_interfaces DirectInterface "${DirectInterface}"
logger -t "${NAME}" -p daemon.warn \
"Using network interface '${iface}' for direct binding"
;;
esac
while [ -n "${iface}" ] ; do
# if network is available (even during boot) - proceed
if network_is_up "${iface}" ; then break ; fi
# skip during boot
[ -z "${BOOT}" ] || return 0
logger -t "${NAME}" -p daemon.crit \
"Network interface '${iface}' is not available!"
return 1
done
while [ -n "${iface}" ] ; do
# ${iface} is logical (higher level) interface name
# ${ndev} is 'real' interface name
# e.g.: if ${iface} is 'lan' (default LAN interface) then ${ndev} is 'br-lan'
network_get_device ndev "${iface}"
[ -z "${ndev}" ] || break
logger -t "${NAME}" -p daemon.crit \
"Missing network device for network interface '${iface}'!"
return 1
done
if [ -n "${iface}" ] ; then
logger -t "${NAME}" -p daemon.info \
"Using network interface '${iface}' (network device '${ndev}') for direct binding"
fi
# handle 'Interface'
while [ -z "${iface}" ] ; do
[ -n "${Interface}" ] || break
# skip during boot
[ -z "${BOOT}" ] || return 0
case "${Interface}" in
*\ *)
warn_multiple_interfaces Interface "${Interface}"
;;
esac
local c=0
# sysoptions.h
local DROPBEAR_MAX_PORTS=10
local a n if_ipaddrs
for n in ${Interface} ; do
[ -n "$n" ] || continue
if_ipaddrs=
network_get_ipaddrs_all if_ipaddrs "$n"
[ -n "${if_ipaddrs}" ] || {
logger -s -t "${NAME}" -p daemon.err \
"Network interface '$n' has no suitable IP address(es)!"
continue
}
[ $c -le ${DROPBEAR_MAX_PORTS} ] || {
logger -s -t "${NAME}" -p daemon.err \
"Network interface '$n' is NOT listened due to option limit exceed!"
continue
}
for a in ${if_ipaddrs} ; do
[ -n "$a" ] || continue
c=$((c+1))
if [ $c -le ${DROPBEAR_MAX_PORTS} ] ; then
ipaddrs="${ipaddrs} $a"
continue
fi
logger -t "${NAME}" -p daemon.err \
"Endpoint '$a:${Port}' on network interface '$n' is NOT listened due to option limit exceed!"
done
done
break
done
PIDCOUNT="$(( ${PIDCOUNT} + 1))"
local pid_file="/var/run/${NAME}.${PIDCOUNT}.pid"
procd_open_instance
procd_set_param command "$PROG" -F -P "$pid_file"
if [ -n "${iface}" ] ; then
# if ${iface} is non-empty then ${ndev} is non-empty too
procd_append_param command -l "${ndev}" -p "${Port}"
else
if [ -z "${ipaddrs}" ] ; then
procd_append_param command -p "${Port}"
else
local a
for a in ${ipaddrs} ; do
[ -n "$a" ] || continue
procd_append_param command -p "$a:${Port}"
done
fi
fi
[ "${PasswordAuth}" -eq 0 ] && procd_append_param command -s
[ "${GatewayPorts}" -eq 1 ] && procd_append_param command -a
[ -n "${ForceCommand}" ] && procd_append_param command -c "${ForceCommand}"
[ "${RootPasswordAuth}" -eq 0 ] && procd_append_param command -g
[ "${RootLogin}" -eq 0 ] && procd_append_param command -w
config_list_foreach "$1" 'keyfile' hk_config__keyfile
if [ -n "${rsakeyfile}" ]; then
logger -s -t "${NAME}" -p daemon.crit \
"Option 'rsakeyfile' is considered to be DEPRECATED and will be REMOVED in future releases, use 'keyfile' list instead"
sed -i.before-upgrade -E -e 's/option(\s+)rsakeyfile/list keyfile/' \
"/etc/config/${NAME}"
logger -s -t "${NAME}" -p daemon.crit \
"Auto-transition 'option rsakeyfile' => 'list keyfile' in /etc/config/${NAME} is done, please verify your configuration"
hk_config 'rsakeyfile' "${rsakeyfile}"
fi
[ -n "${BannerFile}" ] && procd_append_param command -b "${BannerFile}"
[ "${IdleTimeout}" -ne 0 ] && procd_append_param command -I "${IdleTimeout}"
[ "${SSHKeepAlive}" -ne 0 ] && procd_append_param command -K "${SSHKeepAlive}"
[ "${MaxAuthTries}" -ne 0 ] && procd_append_param command -T "${MaxAuthTries}"
[ "${RecvWindowSize}" -gt 0 ] && {
# NB: OpenWrt increases receive window size to increase throughput on high latency links
# ref: validate_section_dropbear()
# default receive window size is 24576 (DEFAULT_RECV_WINDOW in default_options.h)
# sysoptions.h
local MAX_RECV_WINDOW=10485760
if [ "${RecvWindowSize}" -gt ${MAX_RECV_WINDOW} ] ; then
# separate logging is required because syslog misses dropbear's message
# Bad recv window '${RecvWindowSize}', using ${MAX_RECV_WINDOW}
# it's probably dropbear issue but we should handle this and notify user
logger -s -t "${NAME}" -p daemon.warn \
"Option 'RecvWindowSize' is too high (${RecvWindowSize}), limiting to ${MAX_RECV_WINDOW}"
RecvWindowSize=${MAX_RECV_WINDOW}
fi
procd_append_param command -W "${RecvWindowSize}"
}
[ "${mdns}" -ne 0 ] && procd_add_mdns "ssh" "tcp" "$Port" "daemon=dropbear"
procd_set_param respawn
procd_close_instance
}
load_interfaces()
{
local enable
config_get enable "$1" enable 1
[ "${enable}" = "1" ] || return 0
local direct_iface iface
config_get direct_iface "$1" DirectInterface
direct_iface=$(normalize_list "${direct_iface}")
# 'DirectInterface' takes precedence over 'Interface'
if [ -n "${direct_iface}" ] ; then
iface=$(echo "${direct_iface}" | awk '{print $1}')
else
config_get iface "$1" Interface
iface=$(normalize_list "${iface}")
fi
interfaces="${interfaces} ${iface}"
}
boot()
{
BOOT=1
start "$@"
}
start_service()
{
hk_generate_as_needed
file_verify /etc/dropbear/authorized_keys config
. /lib/functions.sh
. /lib/functions/network.sh
config_load "${NAME}"
config_foreach validate_section_dropbear dropbear dropbear_instance
}
service_triggers()
{
local interfaces
procd_add_config_trigger "config.change" "${NAME}" /etc/init.d/dropbear reload
config_load "${NAME}"
config_foreach load_interfaces "${NAME}"
[ -n "${interfaces}" ] && {
local n
for n in $(printf '%s\n' ${interfaces} | sort -u) ; do
procd_add_interface_trigger "interface.*" $n /etc/init.d/dropbear reload
done
}
procd_add_validation validate_section_dropbear
}
shutdown() {
# close all open connections
killall dropbear
}
killclients()
{
local ignore=''
local server
local pid
# if this script is run from inside a client session, then ignore that session
pid="$$"
while [ "${pid}" -ne 0 ]
do
# get parent process id
pid=$(cut -d ' ' -f 4 "/proc/${pid}/stat")
[ "${pid}" -eq 0 ] && break
# check if client connection
grep -F -q -e "${PROG}" "/proc/${pid}/cmdline" && {
append ignore "${pid}"
break
}
done
# get all server pids that should be ignored
for server in $(cat /var/run/${NAME}.*.pid)
do
append ignore "${server}"
done
# get all running pids and kill client connections
local skip
for pid in $(pidof "${NAME}")
do
# check if correct program, otherwise process next pid
grep -F -q -e "${PROG}" "/proc/${pid}/cmdline" || {
continue
}
# check if pid should be ignored (servers, ourself)
skip=0
for server in ${ignore}
do
if [ "${pid}" = "${server}" ]
then
skip=1
break
fi
done
[ "${skip}" -ne 0 ] && continue
# kill process
echo "${initscript}: Killing ${pid}..."
kill -KILL ${pid}
done
}
|