1 |
Add a minimal SOCKSv5-over-UNIX-socket proxy to Portage, and start it |
2 |
whenever ebuilds are started with network-sandbox enabled. Pass the |
3 |
socket address in PORTAGE_SOCKS5_PROXY and DISTCC_SOCKS_PROXY variables. |
4 |
The proxy can be used to escape the network sandbox whenever network |
5 |
access is really desired, e.g. in distcc. |
6 |
|
7 |
The proxy is based on asynchronous I/O using the asyncio module. |
8 |
Therefore, it requires the asyncio module that is built-in in Python 3.4 |
9 |
and available stand-alone for Python 3.3. Escaping the sandbox is not |
10 |
supported with older versions of Python. |
11 |
|
12 |
The proxy supports connecting to IPv6 & IPv4 TCP hosts. UDP and socket |
13 |
binding are not supported. SOCKSv5 authentication schemes are not |
14 |
supported (UNIX sockets provide a security layer). |
15 |
--- |
16 |
bin/save-ebuild-env.sh | 5 +- |
17 |
bin/socks5-server.py | 190 +++++++++++++++++++++ |
18 |
.../package/ebuild/_config/special_env_vars.py | 2 +- |
19 |
pym/portage/package/ebuild/doebuild.py | 11 ++ |
20 |
pym/portage/util/socks5.py | 53 ++++++ |
21 |
5 files changed, 258 insertions(+), 3 deletions(-) |
22 |
create mode 100644 bin/socks5-server.py |
23 |
create mode 100644 pym/portage/util/socks5.py |
24 |
|
25 |
diff --git a/bin/save-ebuild-env.sh b/bin/save-ebuild-env.sh |
26 |
index c6bffb5..477ed28 100644 |
27 |
--- a/bin/save-ebuild-env.sh |
28 |
+++ b/bin/save-ebuild-env.sh |
29 |
@@ -92,7 +92,7 @@ __save_ebuild_env() { |
30 |
|
31 |
# portage config variables and variables set directly by portage |
32 |
unset ACCEPT_LICENSE BAD BRACKET BUILD_PREFIX COLS \ |
33 |
- DISTCC_DIR DISTDIR DOC_SYMLINKS_DIR \ |
34 |
+ DISTCC_DIR DISTCC_SOCKS5_PROXY DISTDIR DOC_SYMLINKS_DIR \ |
35 |
EBUILD_FORCE_TEST EBUILD_MASTER_PID \ |
36 |
ECLASS_DEPTH ENDCOL FAKEROOTKEY \ |
37 |
GOOD HILITE HOME \ |
38 |
@@ -105,7 +105,8 @@ __save_ebuild_env() { |
39 |
PORTAGE_DOHTML_WARN_ON_SKIPPED_FILES \ |
40 |
PORTAGE_NONFATAL PORTAGE_QUIET \ |
41 |
PORTAGE_SANDBOX_DENY PORTAGE_SANDBOX_PREDICT \ |
42 |
- PORTAGE_SANDBOX_READ PORTAGE_SANDBOX_WRITE PREROOTPATH \ |
43 |
+ PORTAGE_SANDBOX_READ PORTAGE_SANDBOX_WRITE \ |
44 |
+ PORTAGE_SOCKS5_PROXY PREROOTPATH \ |
45 |
QA_INTERCEPTORS \ |
46 |
RC_DEFAULT_INDENT RC_DOT_PATTERN RC_ENDCOL RC_INDENTATION \ |
47 |
ROOT ROOTPATH RPMDIR TEMP TMP TMPDIR USE_EXPAND \ |
48 |
diff --git a/bin/socks5-server.py b/bin/socks5-server.py |
49 |
new file mode 100644 |
50 |
index 0000000..6bd71e4 |
51 |
--- /dev/null |
52 |
+++ b/bin/socks5-server.py |
53 |
@@ -0,0 +1,190 @@ |
54 |
+#!/usr/bin/env python |
55 |
+# SOCKSv5 proxy server for network-sandbox |
56 |
+# Copyright 2015 Gentoo Foundation |
57 |
+# Distributed under the terms of the GNU General Public License v2 |
58 |
+ |
59 |
+import asyncio |
60 |
+import errno |
61 |
+import os |
62 |
+import socket |
63 |
+import struct |
64 |
+import sys |
65 |
+ |
66 |
+class Socks5Server(object): |
67 |
+ @asyncio.coroutine |
68 |
+ def handle_proxy_conn(self, reader, writer): |
69 |
+ try: |
70 |
+ # SOCKS hello |
71 |
+ data = yield from reader.readexactly(2) |
72 |
+ vers, method_no = struct.unpack('!BB', data) |
73 |
+ |
74 |
+ if vers != 0x05: |
75 |
+ writer.close() |
76 |
+ return |
77 |
+ |
78 |
+ # ...and auth method list |
79 |
+ data = yield from reader.readexactly(method_no) |
80 |
+ for method in data: |
81 |
+ if method == 0x00: |
82 |
+ break |
83 |
+ else: |
84 |
+ # no supported method |
85 |
+ method = 0xFF |
86 |
+ |
87 |
+ # auth reply |
88 |
+ repl = struct.pack('!BB', 0x05, method) |
89 |
+ writer.write(repl) |
90 |
+ yield from writer.drain() |
91 |
+ if method == 0xFF: |
92 |
+ writer.close() |
93 |
+ return |
94 |
+ |
95 |
+ # request |
96 |
+ data = yield from reader.readexactly(4) |
97 |
+ vers, cmd, rsv, atyp = struct.unpack('!BBBB', data) |
98 |
+ |
99 |
+ if vers != 0x05 or rsv != 0x00: |
100 |
+ self.close() |
101 |
+ return |
102 |
+ |
103 |
+ rpl = 0x00 |
104 |
+ if cmd != 0x01: # CONNECT |
105 |
+ rpl = 0x07 # command not supported |
106 |
+ elif atyp == 0x01: # IPv4 |
107 |
+ data = yield from reader.readexactly(4) |
108 |
+ addr = socket.inet_ntoa(data) |
109 |
+ elif atyp == 0x03: # domain name |
110 |
+ data = yield from reader.readexactly(1) |
111 |
+ addr_len, = struct.unpack('!B', data) |
112 |
+ addr = yield from reader.readexactly(addr_len) |
113 |
+ elif atyp == 0x04: # IPv6 |
114 |
+ data = yield from reader.readexactly(16) |
115 |
+ addr = socket.inet_ntop(socket.AF_INET6, data) |
116 |
+ else: |
117 |
+ rpl = 0x08 # address type not supported |
118 |
+ |
119 |
+ repl_addr = None |
120 |
+ |
121 |
+ # try to connect |
122 |
+ if rpl == 0x00: |
123 |
+ data = yield from reader.readexactly(2) |
124 |
+ port, = struct.unpack('!H', data) |
125 |
+ |
126 |
+ try: |
127 |
+ # establish proxied connection |
128 |
+ proxied_reader, proxied_writer = yield from asyncio.open_connection( |
129 |
+ addr, port) |
130 |
+ except (socket.gaierror, socket.herror): |
131 |
+ rpl = 0x04 # host unreachable |
132 |
+ except OSError as e: |
133 |
+ if e.errno in (errno.ENETUNREACH, errno.ENETDOWN): |
134 |
+ rpl = 0x03 # network unreachable |
135 |
+ elif e.errno in (errno.EHOSTUNREACH, errno.EHOSTDOWN): |
136 |
+ rpl = 0x04 # host unreachable |
137 |
+ elif e.errno in (errno.ECONNREFUSED, errno.ETIMEDOUT): |
138 |
+ rpl = 0x05 # connection refused |
139 |
+ else: |
140 |
+ raise |
141 |
+ else: |
142 |
+ sock = proxied_writer.get_extra_info('socket') |
143 |
+ addr = sock.getsockname() |
144 |
+ if sock.family == socket.AF_INET: |
145 |
+ host, port = addr |
146 |
+ bin_host = socket.inet_aton(host) |
147 |
+ |
148 |
+ repl_addr = struct.pack('!B4sH', |
149 |
+ 0x01, bin_host, port) |
150 |
+ elif sock.family == socket.AF_INET6: |
151 |
+ # discard flowinfo, scope_id |
152 |
+ host, port = addr[:2] |
153 |
+ bin_host = socket.inet_pton(sock.family, host) |
154 |
+ |
155 |
+ repl_addr = struct.pack('!B16sH', |
156 |
+ 0x04, bin_host, port) |
157 |
+ |
158 |
+ if repl_addr is None: |
159 |
+ # fallback to 0.0.0.0:0 |
160 |
+ repl_addr = struct.pack('!BLH', 0x01, 0x00000000, 0x0000) |
161 |
+ |
162 |
+ # reply to the request |
163 |
+ repl = struct.pack('!BBB', 0x05, rpl, 0x00) |
164 |
+ writer.write(repl + repl_addr) |
165 |
+ yield from writer.drain() |
166 |
+ |
167 |
+ # close if an error occured |
168 |
+ if rpl != 0x00: |
169 |
+ writer.close() |
170 |
+ return |
171 |
+ |
172 |
+ # otherwise, start two loops: |
173 |
+ # remote -> local... |
174 |
+ t = asyncio.async(self.handle_proxied_conn( |
175 |
+ proxied_reader, writer, asyncio.Task.current_task())) |
176 |
+ |
177 |
+ # and local -> remote... |
178 |
+ try: |
179 |
+ try: |
180 |
+ while True: |
181 |
+ data = yield from reader.read(4096) |
182 |
+ if data == b'': |
183 |
+ t.cancel() |
184 |
+ break |
185 |
+ |
186 |
+ proxied_writer.write(data) |
187 |
+ yield from proxied_writer.drain() |
188 |
+ except OSError: |
189 |
+ t.cancel() |
190 |
+ except: |
191 |
+ t.cancel() |
192 |
+ raise |
193 |
+ finally: |
194 |
+ proxied_writer.close() |
195 |
+ writer.close() |
196 |
+ |
197 |
+ except (OSError, asyncio.IncompleteReadError, asyncio.CancelledError): |
198 |
+ writer.close() |
199 |
+ return |
200 |
+ except: |
201 |
+ writer.close() |
202 |
+ raise |
203 |
+ |
204 |
+ @asyncio.coroutine |
205 |
+ def handle_proxied_conn(self, proxied_reader, writer, parent_task): |
206 |
+ try: |
207 |
+ try: |
208 |
+ while True: |
209 |
+ data = yield from proxied_reader.read(4096) |
210 |
+ if data == b'': |
211 |
+ break |
212 |
+ |
213 |
+ writer.write(data) |
214 |
+ yield from writer.drain() |
215 |
+ finally: |
216 |
+ parent_task.cancel() |
217 |
+ except (OSError, asyncio.CancelledError): |
218 |
+ return |
219 |
+ |
220 |
+ |
221 |
+if __name__ == '__main__': |
222 |
+ if len(sys.argv) != 2: |
223 |
+ print('Usage: %s <socket-path>' % sys.argv[0]) |
224 |
+ sys.exit(1) |
225 |
+ |
226 |
+ loop = asyncio.get_event_loop() |
227 |
+ s = Socks5Server() |
228 |
+ server = loop.run_until_complete( |
229 |
+ asyncio.start_unix_server(s.handle_proxy_conn, sys.argv[1], loop=loop)) |
230 |
+ |
231 |
+ ret = 0 |
232 |
+ try: |
233 |
+ try: |
234 |
+ loop.run_forever() |
235 |
+ except KeyboardInterrupt: |
236 |
+ pass |
237 |
+ except: |
238 |
+ ret = 1 |
239 |
+ finally: |
240 |
+ server.close() |
241 |
+ loop.run_until_complete(server.wait_closed()) |
242 |
+ loop.close() |
243 |
+ os.unlink(sys.argv[1]) |
244 |
diff --git a/pym/portage/package/ebuild/_config/special_env_vars.py b/pym/portage/package/ebuild/_config/special_env_vars.py |
245 |
index 6bb3c95..905d5e7 100644 |
246 |
--- a/pym/portage/package/ebuild/_config/special_env_vars.py |
247 |
+++ b/pym/portage/package/ebuild/_config/special_env_vars.py |
248 |
@@ -71,7 +71,7 @@ environ_whitelist += [ |
249 |
"PORTAGE_PYM_PATH", "PORTAGE_PYTHON", |
250 |
"PORTAGE_PYTHONPATH", "PORTAGE_QUIET", |
251 |
"PORTAGE_REPO_NAME", "PORTAGE_REPOSITORIES", "PORTAGE_RESTRICT", |
252 |
- "PORTAGE_SIGPIPE_STATUS", |
253 |
+ "PORTAGE_SIGPIPE_STATUS", "PORTAGE_SOCKS5_PROXY", |
254 |
"PORTAGE_TMPDIR", "PORTAGE_UPDATE_ENV", "PORTAGE_USERNAME", |
255 |
"PORTAGE_VERBOSE", "PORTAGE_WORKDIR_MODE", "PORTAGE_XATTR_EXCLUDE", |
256 |
"PORTDIR", "PORTDIR_OVERLAY", "PREROOTPATH", |
257 |
diff --git a/pym/portage/package/ebuild/doebuild.py b/pym/portage/package/ebuild/doebuild.py |
258 |
index 791b5c3..6329b62 100644 |
259 |
--- a/pym/portage/package/ebuild/doebuild.py |
260 |
+++ b/pym/portage/package/ebuild/doebuild.py |
261 |
@@ -68,6 +68,7 @@ from portage.util import apply_recursive_permissions, \ |
262 |
writemsg, writemsg_stdout, write_atomic |
263 |
from portage.util.cpuinfo import get_cpu_count |
264 |
from portage.util.lafilefixer import rewrite_lafile |
265 |
+from portage.util.socks5 import get_socks5_proxy |
266 |
from portage.versions import _pkgsplit |
267 |
from _emerge.BinpkgEnvExtractor import BinpkgEnvExtractor |
268 |
from _emerge.EbuildBuildDir import EbuildBuildDir |
269 |
@@ -1487,6 +1488,16 @@ def spawn(mystring, mysettings, debug=False, free=False, droppriv=False, |
270 |
keywords['unshare_net'] = not networked |
271 |
keywords['unshare_ipc'] = not ipc |
272 |
|
273 |
+ if not networked: |
274 |
+ # Provide a SOCKS5-over-UNIX-socket proxy to escape sandbox |
275 |
+ try: |
276 |
+ proxy = get_socks5_proxy(mysettings) |
277 |
+ except NotImplementedError: |
278 |
+ pass |
279 |
+ else: |
280 |
+ mysettings['PORTAGE_SOCKS5_PROXY'] = proxy |
281 |
+ mysettings['DISTCC_SOCKS_PROXY'] = proxy |
282 |
+ |
283 |
# TODO: Enable fakeroot to be used together with droppriv. The |
284 |
# fake ownership/permissions will have to be converted to real |
285 |
# permissions in the merge phase. |
286 |
diff --git a/pym/portage/util/socks5.py b/pym/portage/util/socks5.py |
287 |
new file mode 100644 |
288 |
index 0000000..286cccf |
289 |
--- /dev/null |
290 |
+++ b/pym/portage/util/socks5.py |
291 |
@@ -0,0 +1,53 @@ |
292 |
+# SOCKSv5 proxy manager for network-sandbox |
293 |
+# Copyright 2015 Gentoo Foundation |
294 |
+# Distributed under the terms of the GNU General Public License v2 |
295 |
+ |
296 |
+import os |
297 |
+import signal |
298 |
+ |
299 |
+from portage import _python_interpreter |
300 |
+from portage.data import portage_gid, portage_uid, userpriv_groups |
301 |
+from portage.process import atexit_register, spawn |
302 |
+ |
303 |
+ |
304 |
+class ProxyManager(object): |
305 |
+ socket_path = None |
306 |
+ _pids = None |
307 |
+ |
308 |
+ def start(self, settings): |
309 |
+ try: |
310 |
+ import asyncio |
311 |
+ except ImportError: |
312 |
+ raise NotImplementedError('SOCKSv5 proxy requires asyncio module') |
313 |
+ |
314 |
+ self.socket_path = os.path.join(settings['PORTAGE_TMPDIR'], |
315 |
+ '.portage.%d.net.sock' % os.getpid()) |
316 |
+ server_bin = os.path.join(settings['PORTAGE_BIN_PATH'], 'socks5-server.py') |
317 |
+ self._pids = spawn([_python_interpreter, server_bin, self.socket_path], |
318 |
+ returnpid=True, uid=portage_uid, gid=portage_gid, |
319 |
+ groups=userpriv_groups, umask=0o077) |
320 |
+ |
321 |
+ atexit_register(self.stop) |
322 |
+ |
323 |
+ def stop(self): |
324 |
+ self.socket_path = None |
325 |
+ |
326 |
+ for p in self._pids: |
327 |
+ os.kill(p, signal.SIGINT) |
328 |
+ os.waitpid(p, 0) |
329 |
+ |
330 |
+ def __bool__(self): |
331 |
+ return self.socket_path is not None |
332 |
+ |
333 |
+ def __nonzero__(self): |
334 |
+ return self.__bool__() |
335 |
+ |
336 |
+ |
337 |
+running_proxy = ProxyManager() |
338 |
+ |
339 |
+ |
340 |
+def get_socks5_proxy(settings): |
341 |
+ if not running_proxy: |
342 |
+ running_proxy.start(settings) |
343 |
+ |
344 |
+ return running_proxy.socket_path |
345 |
-- |
346 |
2.2.2 |