diff options
Diffstat (limited to 'ssh.py')
| -rw-r--r-- | ssh.py | 474 |
1 files changed, 242 insertions, 232 deletions
| @@ -28,254 +28,264 @@ import platform_utils | |||
| 28 | from repo_trace import Trace | 28 | from repo_trace import Trace |
| 29 | 29 | ||
| 30 | 30 | ||
| 31 | PROXY_PATH = os.path.join(os.path.dirname(__file__), 'git_ssh') | 31 | PROXY_PATH = os.path.join(os.path.dirname(__file__), "git_ssh") |
| 32 | 32 | ||
| 33 | 33 | ||
| 34 | def _run_ssh_version(): | 34 | def _run_ssh_version(): |
| 35 | """run ssh -V to display the version number""" | 35 | """run ssh -V to display the version number""" |
| 36 | return subprocess.check_output(['ssh', '-V'], stderr=subprocess.STDOUT).decode() | 36 | return subprocess.check_output( |
| 37 | ["ssh", "-V"], stderr=subprocess.STDOUT | ||
| 38 | ).decode() | ||
| 37 | 39 | ||
| 38 | 40 | ||
| 39 | def _parse_ssh_version(ver_str=None): | 41 | def _parse_ssh_version(ver_str=None): |
| 40 | """parse a ssh version string into a tuple""" | 42 | """parse a ssh version string into a tuple""" |
| 41 | if ver_str is None: | 43 | if ver_str is None: |
| 42 | ver_str = _run_ssh_version() | 44 | ver_str = _run_ssh_version() |
| 43 | m = re.match(r'^OpenSSH_([0-9.]+)(p[0-9]+)?\s', ver_str) | 45 | m = re.match(r"^OpenSSH_([0-9.]+)(p[0-9]+)?\s", ver_str) |
| 44 | if m: | 46 | if m: |
| 45 | return tuple(int(x) for x in m.group(1).split('.')) | 47 | return tuple(int(x) for x in m.group(1).split(".")) |
| 46 | else: | 48 | else: |
| 47 | return () | 49 | return () |
| 48 | 50 | ||
| 49 | 51 | ||
| 50 | @functools.lru_cache(maxsize=None) | 52 | @functools.lru_cache(maxsize=None) |
| 51 | def version(): | 53 | def version(): |
| 52 | """return ssh version as a tuple""" | 54 | """return ssh version as a tuple""" |
| 53 | try: | ||
| 54 | return _parse_ssh_version() | ||
| 55 | except FileNotFoundError: | ||
| 56 | print('fatal: ssh not installed', file=sys.stderr) | ||
| 57 | sys.exit(1) | ||
| 58 | except subprocess.CalledProcessError: | ||
| 59 | print('fatal: unable to detect ssh version', file=sys.stderr) | ||
| 60 | sys.exit(1) | ||
| 61 | |||
| 62 | |||
| 63 | URI_SCP = re.compile(r'^([^@:]*@?[^:/]{1,}):') | ||
| 64 | URI_ALL = re.compile(r'^([a-z][a-z+-]*)://([^@/]*@?[^/]*)/') | ||
| 65 | |||
| 66 | |||
| 67 | class ProxyManager: | ||
| 68 | """Manage various ssh clients & masters that we spawn. | ||
| 69 | |||
| 70 | This will take care of sharing state between multiprocessing children, and | ||
| 71 | make sure that if we crash, we don't leak any of the ssh sessions. | ||
| 72 | |||
| 73 | The code should work with a single-process scenario too, and not add too much | ||
| 74 | overhead due to the manager. | ||
| 75 | """ | ||
| 76 | |||
| 77 | # Path to the ssh program to run which will pass our master settings along. | ||
| 78 | # Set here more as a convenience API. | ||
| 79 | proxy = PROXY_PATH | ||
| 80 | |||
| 81 | def __init__(self, manager): | ||
| 82 | # Protect access to the list of active masters. | ||
| 83 | self._lock = multiprocessing.Lock() | ||
| 84 | # List of active masters (pid). These will be spawned on demand, and we are | ||
| 85 | # responsible for shutting them all down at the end. | ||
| 86 | self._masters = manager.list() | ||
| 87 | # Set of active masters indexed by "host:port" information. | ||
| 88 | # The value isn't used, but multiprocessing doesn't provide a set class. | ||
| 89 | self._master_keys = manager.dict() | ||
| 90 | # Whether ssh masters are known to be broken, so we give up entirely. | ||
| 91 | self._master_broken = manager.Value('b', False) | ||
| 92 | # List of active ssh sesssions. Clients will be added & removed as | ||
| 93 | # connections finish, so this list is just for safety & cleanup if we crash. | ||
| 94 | self._clients = manager.list() | ||
| 95 | # Path to directory for holding master sockets. | ||
| 96 | self._sock_path = None | ||
| 97 | |||
| 98 | def __enter__(self): | ||
| 99 | """Enter a new context.""" | ||
| 100 | return self | ||
| 101 | |||
| 102 | def __exit__(self, exc_type, exc_value, traceback): | ||
| 103 | """Exit a context & clean up all resources.""" | ||
| 104 | self.close() | ||
| 105 | |||
| 106 | def add_client(self, proc): | ||
| 107 | """Track a new ssh session.""" | ||
| 108 | self._clients.append(proc.pid) | ||
| 109 | |||
| 110 | def remove_client(self, proc): | ||
| 111 | """Remove a completed ssh session.""" | ||
| 112 | try: | 55 | try: |
| 113 | self._clients.remove(proc.pid) | 56 | return _parse_ssh_version() |
| 114 | except ValueError: | 57 | except FileNotFoundError: |
| 115 | pass | 58 | print("fatal: ssh not installed", file=sys.stderr) |
| 116 | 59 | sys.exit(1) | |
| 117 | def add_master(self, proc): | 60 | except subprocess.CalledProcessError: |
| 118 | """Track a new master connection.""" | 61 | print("fatal: unable to detect ssh version", file=sys.stderr) |
| 119 | self._masters.append(proc.pid) | 62 | sys.exit(1) |
| 120 | |||
| 121 | def _terminate(self, procs): | ||
| 122 | """Kill all |procs|.""" | ||
| 123 | for pid in procs: | ||
| 124 | try: | ||
| 125 | os.kill(pid, signal.SIGTERM) | ||
| 126 | os.waitpid(pid, 0) | ||
| 127 | except OSError: | ||
| 128 | pass | ||
| 129 | |||
| 130 | # The multiprocessing.list() API doesn't provide many standard list() | ||
| 131 | # methods, so we have to manually clear the list. | ||
| 132 | while True: | ||
| 133 | try: | ||
| 134 | procs.pop(0) | ||
| 135 | except: | ||
| 136 | break | ||
| 137 | |||
| 138 | def close(self): | ||
| 139 | """Close this active ssh session. | ||
| 140 | |||
| 141 | Kill all ssh clients & masters we created, and nuke the socket dir. | ||
| 142 | """ | ||
| 143 | self._terminate(self._clients) | ||
| 144 | self._terminate(self._masters) | ||
| 145 | |||
| 146 | d = self.sock(create=False) | ||
| 147 | if d: | ||
| 148 | try: | ||
| 149 | platform_utils.rmdir(os.path.dirname(d)) | ||
| 150 | except OSError: | ||
| 151 | pass | ||
| 152 | |||
| 153 | def _open_unlocked(self, host, port=None): | ||
| 154 | """Make sure a ssh master session exists for |host| & |port|. | ||
| 155 | 63 | ||
| 156 | If one doesn't exist already, we'll create it. | ||
| 157 | 64 | ||
| 158 | We won't grab any locks, so the caller has to do that. This helps keep the | 65 | URI_SCP = re.compile(r"^([^@:]*@?[^:/]{1,}):") |
| 159 | business logic of actually creating the master separate from grabbing locks. | 66 | URI_ALL = re.compile(r"^([a-z][a-z+-]*)://([^@/]*@?[^/]*)/") |
| 160 | """ | ||
| 161 | # Check to see whether we already think that the master is running; if we | ||
| 162 | # think it's already running, return right away. | ||
| 163 | if port is not None: | ||
| 164 | key = '%s:%s' % (host, port) | ||
| 165 | else: | ||
| 166 | key = host | ||
| 167 | |||
| 168 | if key in self._master_keys: | ||
| 169 | return True | ||
| 170 | |||
| 171 | if self._master_broken.value or 'GIT_SSH' in os.environ: | ||
| 172 | # Failed earlier, so don't retry. | ||
| 173 | return False | ||
| 174 | |||
| 175 | # We will make two calls to ssh; this is the common part of both calls. | ||
| 176 | command_base = ['ssh', '-o', 'ControlPath %s' % self.sock(), host] | ||
| 177 | if port is not None: | ||
| 178 | command_base[1:1] = ['-p', str(port)] | ||
| 179 | |||
| 180 | # Since the key wasn't in _master_keys, we think that master isn't running. | ||
| 181 | # ...but before actually starting a master, we'll double-check. This can | ||
| 182 | # be important because we can't tell that that 'git@myhost.com' is the same | ||
| 183 | # as 'myhost.com' where "User git" is setup in the user's ~/.ssh/config file. | ||
| 184 | check_command = command_base + ['-O', 'check'] | ||
| 185 | with Trace('Call to ssh (check call): %s', ' '.join(check_command)): | ||
| 186 | try: | ||
| 187 | check_process = subprocess.Popen(check_command, | ||
| 188 | stdout=subprocess.PIPE, | ||
| 189 | stderr=subprocess.PIPE) | ||
| 190 | check_process.communicate() # read output, but ignore it... | ||
| 191 | isnt_running = check_process.wait() | ||
| 192 | |||
| 193 | if not isnt_running: | ||
| 194 | # Our double-check found that the master _was_ infact running. Add to | ||
| 195 | # the list of keys. | ||
| 196 | self._master_keys[key] = True | ||
| 197 | return True | ||
| 198 | except Exception: | ||
| 199 | # Ignore excpetions. We we will fall back to the normal command and | ||
| 200 | # print to the log there. | ||
| 201 | pass | ||
| 202 | |||
| 203 | command = command_base[:1] + ['-M', '-N'] + command_base[1:] | ||
| 204 | p = None | ||
| 205 | try: | ||
| 206 | with Trace('Call to ssh: %s', ' '.join(command)): | ||
| 207 | p = subprocess.Popen(command) | ||
| 208 | except Exception as e: | ||
| 209 | self._master_broken.value = True | ||
| 210 | print('\nwarn: cannot enable ssh control master for %s:%s\n%s' | ||
| 211 | % (host, port, str(e)), file=sys.stderr) | ||
| 212 | return False | ||
| 213 | 67 | ||
| 214 | time.sleep(1) | ||
| 215 | ssh_died = (p.poll() is not None) | ||
| 216 | if ssh_died: | ||
| 217 | return False | ||
| 218 | 68 | ||
| 219 | self.add_master(p) | 69 | class ProxyManager: |
| 220 | self._master_keys[key] = True | 70 | """Manage various ssh clients & masters that we spawn. |
| 221 | return True | ||
| 222 | |||
| 223 | def _open(self, host, port=None): | ||
| 224 | """Make sure a ssh master session exists for |host| & |port|. | ||
| 225 | 71 | ||
| 226 | If one doesn't exist already, we'll create it. | 72 | This will take care of sharing state between multiprocessing children, and |
| 73 | make sure that if we crash, we don't leak any of the ssh sessions. | ||
| 227 | 74 | ||
| 228 | This will obtain any necessary locks to avoid inter-process races. | 75 | The code should work with a single-process scenario too, and not add too |
| 76 | much overhead due to the manager. | ||
| 229 | """ | 77 | """ |
| 230 | # Bail before grabbing the lock if we already know that we aren't going to | ||
| 231 | # try creating new masters below. | ||
| 232 | if sys.platform in ('win32', 'cygwin'): | ||
| 233 | return False | ||
| 234 | |||
| 235 | # Acquire the lock. This is needed to prevent opening multiple masters for | ||
| 236 | # the same host when we're running "repo sync -jN" (for N > 1) _and_ the | ||
| 237 | # manifest <remote fetch="ssh://xyz"> specifies a different host from the | ||
| 238 | # one that was passed to repo init. | ||
| 239 | with self._lock: | ||
| 240 | return self._open_unlocked(host, port) | ||
| 241 | |||
| 242 | def preconnect(self, url): | ||
| 243 | """If |uri| will create a ssh connection, setup the ssh master for it.""" | ||
| 244 | m = URI_ALL.match(url) | ||
| 245 | if m: | ||
| 246 | scheme = m.group(1) | ||
| 247 | host = m.group(2) | ||
| 248 | if ':' in host: | ||
| 249 | host, port = host.split(':') | ||
| 250 | else: | ||
| 251 | port = None | ||
| 252 | if scheme in ('ssh', 'git+ssh', 'ssh+git'): | ||
| 253 | return self._open(host, port) | ||
| 254 | return False | ||
| 255 | |||
| 256 | m = URI_SCP.match(url) | ||
| 257 | if m: | ||
| 258 | host = m.group(1) | ||
| 259 | return self._open(host) | ||
| 260 | |||
| 261 | return False | ||
| 262 | 78 | ||
| 263 | def sock(self, create=True): | 79 | # Path to the ssh program to run which will pass our master settings along. |
| 264 | """Return the path to the ssh socket dir. | 80 | # Set here more as a convenience API. |
| 265 | 81 | proxy = PROXY_PATH | |
| 266 | This has all the master sockets so clients can talk to them. | 82 | |
| 267 | """ | 83 | def __init__(self, manager): |
| 268 | if self._sock_path is None: | 84 | # Protect access to the list of active masters. |
| 269 | if not create: | 85 | self._lock = multiprocessing.Lock() |
| 270 | return None | 86 | # List of active masters (pid). These will be spawned on demand, and we |
| 271 | tmp_dir = '/tmp' | 87 | # are responsible for shutting them all down at the end. |
| 272 | if not os.path.exists(tmp_dir): | 88 | self._masters = manager.list() |
| 273 | tmp_dir = tempfile.gettempdir() | 89 | # Set of active masters indexed by "host:port" information. |
| 274 | if version() < (6, 7): | 90 | # The value isn't used, but multiprocessing doesn't provide a set class. |
| 275 | tokens = '%r@%h:%p' | 91 | self._master_keys = manager.dict() |
| 276 | else: | 92 | # Whether ssh masters are known to be broken, so we give up entirely. |
| 277 | tokens = '%C' # hash of %l%h%p%r | 93 | self._master_broken = manager.Value("b", False) |
| 278 | self._sock_path = os.path.join( | 94 | # List of active ssh sesssions. Clients will be added & removed as |
| 279 | tempfile.mkdtemp('', 'ssh-', tmp_dir), | 95 | # connections finish, so this list is just for safety & cleanup if we |
| 280 | 'master-' + tokens) | 96 | # crash. |
| 281 | return self._sock_path | 97 | self._clients = manager.list() |
| 98 | # Path to directory for holding master sockets. | ||
| 99 | self._sock_path = None | ||
| 100 | |||
| 101 | def __enter__(self): | ||
| 102 | """Enter a new context.""" | ||
| 103 | return self | ||
| 104 | |||
| 105 | def __exit__(self, exc_type, exc_value, traceback): | ||
| 106 | """Exit a context & clean up all resources.""" | ||
| 107 | self.close() | ||
| 108 | |||
| 109 | def add_client(self, proc): | ||
| 110 | """Track a new ssh session.""" | ||
| 111 | self._clients.append(proc.pid) | ||
| 112 | |||
| 113 | def remove_client(self, proc): | ||
| 114 | """Remove a completed ssh session.""" | ||
| 115 | try: | ||
| 116 | self._clients.remove(proc.pid) | ||
| 117 | except ValueError: | ||
| 118 | pass | ||
| 119 | |||
| 120 | def add_master(self, proc): | ||
| 121 | """Track a new master connection.""" | ||
| 122 | self._masters.append(proc.pid) | ||
| 123 | |||
| 124 | def _terminate(self, procs): | ||
| 125 | """Kill all |procs|.""" | ||
| 126 | for pid in procs: | ||
| 127 | try: | ||
| 128 | os.kill(pid, signal.SIGTERM) | ||
| 129 | os.waitpid(pid, 0) | ||
| 130 | except OSError: | ||
| 131 | pass | ||
| 132 | |||
| 133 | # The multiprocessing.list() API doesn't provide many standard list() | ||
| 134 | # methods, so we have to manually clear the list. | ||
| 135 | while True: | ||
| 136 | try: | ||
| 137 | procs.pop(0) | ||
| 138 | except: # noqa: E722 | ||
| 139 | break | ||
| 140 | |||
| 141 | def close(self): | ||
| 142 | """Close this active ssh session. | ||
| 143 | |||
| 144 | Kill all ssh clients & masters we created, and nuke the socket dir. | ||
| 145 | """ | ||
| 146 | self._terminate(self._clients) | ||
| 147 | self._terminate(self._masters) | ||
| 148 | |||
| 149 | d = self.sock(create=False) | ||
| 150 | if d: | ||
| 151 | try: | ||
| 152 | platform_utils.rmdir(os.path.dirname(d)) | ||
| 153 | except OSError: | ||
| 154 | pass | ||
| 155 | |||
| 156 | def _open_unlocked(self, host, port=None): | ||
| 157 | """Make sure a ssh master session exists for |host| & |port|. | ||
| 158 | |||
| 159 | If one doesn't exist already, we'll create it. | ||
| 160 | |||
| 161 | We won't grab any locks, so the caller has to do that. This helps keep | ||
| 162 | the business logic of actually creating the master separate from | ||
| 163 | grabbing locks. | ||
| 164 | """ | ||
| 165 | # Check to see whether we already think that the master is running; if | ||
| 166 | # we think it's already running, return right away. | ||
| 167 | if port is not None: | ||
| 168 | key = "%s:%s" % (host, port) | ||
| 169 | else: | ||
| 170 | key = host | ||
| 171 | |||
| 172 | if key in self._master_keys: | ||
| 173 | return True | ||
| 174 | |||
| 175 | if self._master_broken.value or "GIT_SSH" in os.environ: | ||
| 176 | # Failed earlier, so don't retry. | ||
| 177 | return False | ||
| 178 | |||
| 179 | # We will make two calls to ssh; this is the common part of both calls. | ||
| 180 | command_base = ["ssh", "-o", "ControlPath %s" % self.sock(), host] | ||
| 181 | if port is not None: | ||
| 182 | command_base[1:1] = ["-p", str(port)] | ||
| 183 | |||
| 184 | # Since the key wasn't in _master_keys, we think that master isn't | ||
| 185 | # running... but before actually starting a master, we'll double-check. | ||
| 186 | # This can be important because we can't tell that that 'git@myhost.com' | ||
| 187 | # is the same as 'myhost.com' where "User git" is setup in the user's | ||
| 188 | # ~/.ssh/config file. | ||
| 189 | check_command = command_base + ["-O", "check"] | ||
| 190 | with Trace("Call to ssh (check call): %s", " ".join(check_command)): | ||
| 191 | try: | ||
| 192 | check_process = subprocess.Popen( | ||
| 193 | check_command, | ||
| 194 | stdout=subprocess.PIPE, | ||
| 195 | stderr=subprocess.PIPE, | ||
| 196 | ) | ||
| 197 | check_process.communicate() # read output, but ignore it... | ||
| 198 | isnt_running = check_process.wait() | ||
| 199 | |||
| 200 | if not isnt_running: | ||
| 201 | # Our double-check found that the master _was_ infact | ||
| 202 | # running. Add to the list of keys. | ||
| 203 | self._master_keys[key] = True | ||
| 204 | return True | ||
| 205 | except Exception: | ||
| 206 | # Ignore excpetions. We we will fall back to the normal command | ||
| 207 | # and print to the log there. | ||
| 208 | pass | ||
| 209 | |||
| 210 | command = command_base[:1] + ["-M", "-N"] + command_base[1:] | ||
| 211 | p = None | ||
| 212 | try: | ||
| 213 | with Trace("Call to ssh: %s", " ".join(command)): | ||
| 214 | p = subprocess.Popen(command) | ||
| 215 | except Exception as e: | ||
| 216 | self._master_broken.value = True | ||
| 217 | print( | ||
| 218 | "\nwarn: cannot enable ssh control master for %s:%s\n%s" | ||
| 219 | % (host, port, str(e)), | ||
| 220 | file=sys.stderr, | ||
| 221 | ) | ||
| 222 | return False | ||
| 223 | |||
| 224 | time.sleep(1) | ||
| 225 | ssh_died = p.poll() is not None | ||
| 226 | if ssh_died: | ||
| 227 | return False | ||
| 228 | |||
| 229 | self.add_master(p) | ||
| 230 | self._master_keys[key] = True | ||
| 231 | return True | ||
| 232 | |||
| 233 | def _open(self, host, port=None): | ||
| 234 | """Make sure a ssh master session exists for |host| & |port|. | ||
| 235 | |||
| 236 | If one doesn't exist already, we'll create it. | ||
| 237 | |||
| 238 | This will obtain any necessary locks to avoid inter-process races. | ||
| 239 | """ | ||
| 240 | # Bail before grabbing the lock if we already know that we aren't going | ||
| 241 | # to try creating new masters below. | ||
| 242 | if sys.platform in ("win32", "cygwin"): | ||
| 243 | return False | ||
| 244 | |||
| 245 | # Acquire the lock. This is needed to prevent opening multiple masters | ||
| 246 | # for the same host when we're running "repo sync -jN" (for N > 1) _and_ | ||
| 247 | # the manifest <remote fetch="ssh://xyz"> specifies a different host | ||
| 248 | # from the one that was passed to repo init. | ||
| 249 | with self._lock: | ||
| 250 | return self._open_unlocked(host, port) | ||
| 251 | |||
| 252 | def preconnect(self, url): | ||
| 253 | """If |uri| will create a ssh connection, setup the ssh master for it.""" # noqa: E501 | ||
| 254 | m = URI_ALL.match(url) | ||
| 255 | if m: | ||
| 256 | scheme = m.group(1) | ||
| 257 | host = m.group(2) | ||
| 258 | if ":" in host: | ||
| 259 | host, port = host.split(":") | ||
| 260 | else: | ||
| 261 | port = None | ||
| 262 | if scheme in ("ssh", "git+ssh", "ssh+git"): | ||
| 263 | return self._open(host, port) | ||
| 264 | return False | ||
| 265 | |||
| 266 | m = URI_SCP.match(url) | ||
| 267 | if m: | ||
| 268 | host = m.group(1) | ||
| 269 | return self._open(host) | ||
| 270 | |||
| 271 | return False | ||
| 272 | |||
| 273 | def sock(self, create=True): | ||
| 274 | """Return the path to the ssh socket dir. | ||
| 275 | |||
| 276 | This has all the master sockets so clients can talk to them. | ||
| 277 | """ | ||
| 278 | if self._sock_path is None: | ||
| 279 | if not create: | ||
| 280 | return None | ||
| 281 | tmp_dir = "/tmp" | ||
| 282 | if not os.path.exists(tmp_dir): | ||
| 283 | tmp_dir = tempfile.gettempdir() | ||
| 284 | if version() < (6, 7): | ||
| 285 | tokens = "%r@%h:%p" | ||
| 286 | else: | ||
| 287 | tokens = "%C" # hash of %l%h%p%r | ||
| 288 | self._sock_path = os.path.join( | ||
| 289 | tempfile.mkdtemp("", "ssh-", tmp_dir), "master-" + tokens | ||
| 290 | ) | ||
| 291 | return self._sock_path | ||
