author | trims |
Thu, 27 May 2010 19:08:38 -0700 | |
changeset 5547 | f4b087cbb361 |
parent 5410 | c4b979417733 |
child 6170 | 82aea418ab2d |
permissions | -rw-r--r-- |
1 | 1 |
/* |
5547
f4b087cbb361
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
5410
diff
changeset
|
2 |
* Copyright (c) 2005, 2008, Oracle and/or its affiliates. All rights reserved. |
1 | 3 |
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
4 |
* |
|
5 |
* This code is free software; you can redistribute it and/or modify it |
|
6 |
* under the terms of the GNU General Public License version 2 only, as |
|
7 |
* published by the Free Software Foundation. |
|
8 |
* |
|
9 |
* This code is distributed in the hope that it will be useful, but WITHOUT |
|
10 |
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
|
11 |
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
|
12 |
* version 2 for more details (a copy is included in the LICENSE file that |
|
13 |
* accompanied this code). |
|
14 |
* |
|
15 |
* You should have received a copy of the GNU General Public License version |
|
16 |
* 2 along with this work; if not, write to the Free Software Foundation, |
|
17 |
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
|
18 |
* |
|
5547
f4b087cbb361
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
5410
diff
changeset
|
19 |
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
f4b087cbb361
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
5410
diff
changeset
|
20 |
* or visit www.oracle.com if you need additional information or have any |
f4b087cbb361
6941466: Oracle rebranding changes for Hotspot repositories
trims
parents:
5410
diff
changeset
|
21 |
* questions. |
1 | 22 |
* |
23 |
*/ |
|
24 |
||
25 |
# include "incls/_precompiled.incl" |
|
26 |
# include "incls/_attachListener_linux.cpp.incl" |
|
27 |
||
28 |
#include <unistd.h> |
|
29 |
#include <signal.h> |
|
30 |
#include <sys/types.h> |
|
31 |
#include <sys/socket.h> |
|
32 |
#include <sys/un.h> |
|
33 |
#include <sys/stat.h> |
|
34 |
||
35 |
// The attach mechanism on Linux uses a UNIX domain socket. An attach listener |
|
36 |
// thread is created at startup or is created on-demand via a signal from |
|
37 |
// the client tool. The attach listener creates a socket and binds it to a file |
|
38 |
// in the filesystem. The attach listener then acts as a simple (single- |
|
39 |
// threaded) server - tt waits for a client to connect, reads the request, |
|
40 |
// executes it, and returns the response to the client via the socket |
|
41 |
// connection. |
|
42 |
// |
|
43 |
// As the socket is a UNIX domain socket it means that only clients on the |
|
44 |
// local machine can connect. In addition there are two other aspects to |
|
45 |
// the security: |
|
46 |
// 1. The well known file that the socket is bound to has permission 400 |
|
47 |
// 2. When a client connect, the SO_PEERCRED socket option is used to |
|
48 |
// obtain the credentials of client. We check that the effective uid |
|
49 |
// of the client matches this process. |
|
50 |
||
51 |
// forward reference |
|
52 |
class LinuxAttachOperation; |
|
53 |
||
54 |
class LinuxAttachListener: AllStatic { |
|
55 |
private: |
|
56 |
// the path to which we bind the UNIX domain socket |
|
57 |
static char _path[PATH_MAX+1]; |
|
58 |
static bool _has_path; |
|
59 |
||
60 |
// the file descriptor for the listening socket |
|
61 |
static int _listener; |
|
62 |
||
63 |
static void set_path(char* path) { |
|
64 |
if (path == NULL) { |
|
65 |
_has_path = false; |
|
66 |
} else { |
|
67 |
strncpy(_path, path, PATH_MAX); |
|
68 |
_path[PATH_MAX] = '\0'; |
|
69 |
_has_path = true; |
|
70 |
} |
|
71 |
} |
|
72 |
||
73 |
static void set_listener(int s) { _listener = s; } |
|
74 |
||
75 |
// reads a request from the given connected socket |
|
76 |
static LinuxAttachOperation* read_request(int s); |
|
77 |
||
78 |
public: |
|
79 |
enum { |
|
80 |
ATTACH_PROTOCOL_VER = 1 // protocol version |
|
81 |
}; |
|
82 |
enum { |
|
83 |
ATTACH_ERROR_BADVERSION = 101 // error codes |
|
84 |
}; |
|
85 |
||
86 |
// initialize the listener, returns 0 if okay |
|
87 |
static int init(); |
|
88 |
||
89 |
static char* path() { return _path; } |
|
90 |
static bool has_path() { return _has_path; } |
|
91 |
static int listener() { return _listener; } |
|
92 |
||
93 |
// write the given buffer to a socket |
|
94 |
static int write_fully(int s, char* buf, int len); |
|
95 |
||
96 |
static LinuxAttachOperation* dequeue(); |
|
97 |
}; |
|
98 |
||
99 |
class LinuxAttachOperation: public AttachOperation { |
|
100 |
private: |
|
101 |
// the connection to the client |
|
102 |
int _socket; |
|
103 |
||
104 |
public: |
|
105 |
void complete(jint res, bufferedStream* st); |
|
106 |
||
107 |
void set_socket(int s) { _socket = s; } |
|
108 |
int socket() const { return _socket; } |
|
109 |
||
110 |
LinuxAttachOperation(char* name) : AttachOperation(name) { |
|
111 |
set_socket(-1); |
|
112 |
} |
|
113 |
}; |
|
114 |
||
115 |
// statics |
|
116 |
char LinuxAttachListener::_path[PATH_MAX+1]; |
|
117 |
bool LinuxAttachListener::_has_path; |
|
118 |
int LinuxAttachListener::_listener = -1; |
|
119 |
||
120 |
// Supporting class to help split a buffer into individual components |
|
121 |
class ArgumentIterator : public StackObj { |
|
122 |
private: |
|
123 |
char* _pos; |
|
124 |
char* _end; |
|
125 |
public: |
|
126 |
ArgumentIterator(char* arg_buffer, size_t arg_size) { |
|
127 |
_pos = arg_buffer; |
|
128 |
_end = _pos + arg_size - 1; |
|
129 |
} |
|
130 |
char* next() { |
|
131 |
if (*_pos == '\0') { |
|
132 |
return NULL; |
|
133 |
} |
|
134 |
char* res = _pos; |
|
135 |
char* next_pos = strchr(_pos, '\0'); |
|
136 |
if (next_pos < _end) { |
|
137 |
next_pos++; |
|
138 |
} |
|
139 |
_pos = next_pos; |
|
140 |
return res; |
|
141 |
} |
|
142 |
}; |
|
143 |
||
144 |
||
145 |
// atexit hook to stop listener and unlink the file that it is |
|
146 |
// bound too. |
|
147 |
extern "C" { |
|
148 |
static void listener_cleanup() { |
|
149 |
static int cleanup_done; |
|
150 |
if (!cleanup_done) { |
|
151 |
cleanup_done = 1; |
|
152 |
int s = LinuxAttachListener::listener(); |
|
153 |
if (s != -1) { |
|
154 |
::close(s); |
|
155 |
} |
|
156 |
if (LinuxAttachListener::has_path()) { |
|
157 |
::unlink(LinuxAttachListener::path()); |
|
158 |
} |
|
159 |
} |
|
160 |
} |
|
161 |
} |
|
162 |
||
163 |
// Initialization - create a listener socket and bind it to a file |
|
164 |
||
165 |
int LinuxAttachListener::init() { |
|
166 |
char path[PATH_MAX+1]; // socket file |
|
167 |
int listener; // listener socket (file descriptor) |
|
168 |
||
169 |
// register function to cleanup |
|
170 |
::atexit(listener_cleanup); |
|
171 |
||
172 |
// create the listener socket |
|
173 |
listener = ::socket(PF_UNIX, SOCK_STREAM, 0); |
|
174 |
if (listener == -1) { |
|
175 |
return -1; |
|
176 |
} |
|
177 |
||
178 |
int res = -1; |
|
179 |
struct sockaddr_un addr; |
|
180 |
addr.sun_family = AF_UNIX; |
|
181 |
||
182 |
// FIXME: Prior to b39 the tool-side API expected to find the well |
|
183 |
// known file in the working directory. To allow this libjvm.so work with |
|
184 |
// a pre-b39 SDK we create it in the working directory if |
|
185 |
// +StartAttachListener is used is used. All unit tests for this feature |
|
186 |
// currently used this flag. Once b39 SDK has been promoted we can remove |
|
187 |
// this code. |
|
188 |
if (StartAttachListener) { |
|
189 |
sprintf(path, ".java_pid%d", os::current_process_id()); |
|
190 |
strcpy(addr.sun_path, path); |
|
191 |
::unlink(path); |
|
192 |
res = ::bind(listener, (struct sockaddr*)&addr, sizeof(addr)); |
|
193 |
} |
|
194 |
if (res == -1) { |
|
5237
aab592fd4f44
6938627: Make temporary directory use property java.io.tmpdir when specified
coleenp
parents:
670
diff
changeset
|
195 |
snprintf(path, PATH_MAX+1, "%s/.java_pid%d", |
aab592fd4f44
6938627: Make temporary directory use property java.io.tmpdir when specified
coleenp
parents:
670
diff
changeset
|
196 |
os::get_temp_directory(), os::current_process_id()); |
1 | 197 |
strcpy(addr.sun_path, path); |
198 |
::unlink(path); |
|
199 |
res = ::bind(listener, (struct sockaddr*)&addr, sizeof(addr)); |
|
200 |
} |
|
201 |
if (res == -1) { |
|
202 |
RESTARTABLE(::close(listener), res); |
|
203 |
return -1; |
|
204 |
} |
|
205 |
set_path(path); |
|
206 |
||
207 |
// put in listen mode and set permission |
|
208 |
if ((::listen(listener, 5) == -1) || (::chmod(path, S_IREAD|S_IWRITE) == -1)) { |
|
209 |
RESTARTABLE(::close(listener), res); |
|
210 |
::unlink(path); |
|
211 |
set_path(NULL); |
|
212 |
return -1; |
|
213 |
} |
|
214 |
set_listener(listener); |
|
215 |
||
216 |
return 0; |
|
217 |
} |
|
218 |
||
219 |
// Given a socket that is connected to a peer we read the request and |
|
220 |
// create an AttachOperation. As the socket is blocking there is potential |
|
221 |
// for a denial-of-service if the peer does not response. However this happens |
|
222 |
// after the peer credentials have been checked and in the worst case it just |
|
223 |
// means that the attach listener thread is blocked. |
|
224 |
// |
|
225 |
LinuxAttachOperation* LinuxAttachListener::read_request(int s) { |
|
226 |
char ver_str[8]; |
|
227 |
sprintf(ver_str, "%d", ATTACH_PROTOCOL_VER); |
|
228 |
||
229 |
// The request is a sequence of strings so we first figure out the |
|
230 |
// expected count and the maximum possible length of the request. |
|
231 |
// The request is: |
|
232 |
// <ver>0<cmd>0<arg>0<arg>0<arg>0 |
|
233 |
// where <ver> is the protocol version (1), <cmd> is the command |
|
234 |
// name ("load", "datadump", ...), and <arg> is an argument |
|
235 |
int expected_str_count = 2 + AttachOperation::arg_count_max; |
|
223
5c3b023117d9
6452081: 3/4 Allow for Linux builds with Sun Studio Linux compilers
dcubed
parents:
1
diff
changeset
|
236 |
const int max_len = (sizeof(ver_str) + 1) + (AttachOperation::name_length_max + 1) + |
1 | 237 |
AttachOperation::arg_count_max*(AttachOperation::arg_length_max + 1); |
238 |
||
239 |
char buf[max_len]; |
|
240 |
int str_count = 0; |
|
241 |
||
242 |
// Read until all (expected) strings have been read, the buffer is |
|
243 |
// full, or EOF. |
|
244 |
||
245 |
int off = 0; |
|
246 |
int left = max_len; |
|
247 |
||
248 |
do { |
|
249 |
int n; |
|
250 |
RESTARTABLE(read(s, buf+off, left), n); |
|
251 |
if (n == -1) { |
|
252 |
return NULL; // reset by peer or other error |
|
253 |
} |
|
254 |
if (n == 0) { |
|
255 |
break; |
|
256 |
} |
|
257 |
for (int i=0; i<n; i++) { |
|
258 |
if (buf[off+i] == 0) { |
|
259 |
// EOS found |
|
260 |
str_count++; |
|
261 |
||
262 |
// The first string is <ver> so check it now to |
|
263 |
// check for protocol mis-match |
|
264 |
if (str_count == 1) { |
|
265 |
if ((strlen(buf) != strlen(ver_str)) || |
|
266 |
(atoi(buf) != ATTACH_PROTOCOL_VER)) { |
|
267 |
char msg[32]; |
|
268 |
sprintf(msg, "%d\n", ATTACH_ERROR_BADVERSION); |
|
269 |
write_fully(s, msg, strlen(msg)); |
|
270 |
return NULL; |
|
271 |
} |
|
272 |
} |
|
273 |
} |
|
274 |
} |
|
275 |
off += n; |
|
276 |
left -= n; |
|
277 |
} while (left > 0 && str_count < expected_str_count); |
|
278 |
||
279 |
if (str_count != expected_str_count) { |
|
280 |
return NULL; // incomplete request |
|
281 |
} |
|
282 |
||
283 |
// parse request |
|
284 |
||
285 |
ArgumentIterator args(buf, (max_len)-left); |
|
286 |
||
287 |
// version already checked |
|
288 |
char* v = args.next(); |
|
289 |
||
290 |
char* name = args.next(); |
|
291 |
if (name == NULL || strlen(name) > AttachOperation::name_length_max) { |
|
292 |
return NULL; |
|
293 |
} |
|
294 |
||
295 |
LinuxAttachOperation* op = new LinuxAttachOperation(name); |
|
296 |
||
297 |
for (int i=0; i<AttachOperation::arg_count_max; i++) { |
|
298 |
char* arg = args.next(); |
|
299 |
if (arg == NULL) { |
|
300 |
op->set_arg(i, NULL); |
|
301 |
} else { |
|
302 |
if (strlen(arg) > AttachOperation::arg_length_max) { |
|
303 |
delete op; |
|
304 |
return NULL; |
|
305 |
} |
|
306 |
op->set_arg(i, arg); |
|
307 |
} |
|
308 |
} |
|
309 |
||
310 |
op->set_socket(s); |
|
311 |
return op; |
|
312 |
} |
|
313 |
||
314 |
||
315 |
// Dequeue an operation |
|
316 |
// |
|
317 |
// In the Linux implementation there is only a single operation and clients |
|
318 |
// cannot queue commands (except at the socket level). |
|
319 |
// |
|
320 |
LinuxAttachOperation* LinuxAttachListener::dequeue() { |
|
321 |
for (;;) { |
|
322 |
int s; |
|
323 |
||
324 |
// wait for client to connect |
|
325 |
struct sockaddr addr; |
|
326 |
socklen_t len = sizeof(addr); |
|
327 |
RESTARTABLE(::accept(listener(), &addr, &len), s); |
|
328 |
if (s == -1) { |
|
329 |
return NULL; // log a warning? |
|
330 |
} |
|
331 |
||
332 |
// get the credentials of the peer and check the effective uid/guid |
|
333 |
// - check with jeff on this. |
|
334 |
struct ucred cred_info; |
|
335 |
socklen_t optlen = sizeof(cred_info); |
|
336 |
if (::getsockopt(s, SOL_SOCKET, SO_PEERCRED, (void*)&cred_info, &optlen) == -1) { |
|
337 |
int res; |
|
338 |
RESTARTABLE(::close(s), res); |
|
339 |
continue; |
|
340 |
} |
|
341 |
uid_t euid = geteuid(); |
|
342 |
gid_t egid = getegid(); |
|
343 |
||
344 |
if (cred_info.uid != euid || cred_info.gid != egid) { |
|
345 |
int res; |
|
346 |
RESTARTABLE(::close(s), res); |
|
347 |
continue; |
|
348 |
} |
|
349 |
||
350 |
// peer credential look okay so we read the request |
|
351 |
LinuxAttachOperation* op = read_request(s); |
|
352 |
if (op == NULL) { |
|
353 |
int res; |
|
354 |
RESTARTABLE(::close(s), res); |
|
355 |
continue; |
|
356 |
} else { |
|
357 |
return op; |
|
358 |
} |
|
359 |
} |
|
360 |
} |
|
361 |
||
362 |
// write the given buffer to the socket |
|
363 |
int LinuxAttachListener::write_fully(int s, char* buf, int len) { |
|
364 |
do { |
|
365 |
int n = ::write(s, buf, len); |
|
366 |
if (n == -1) { |
|
367 |
if (errno != EINTR) return -1; |
|
368 |
} else { |
|
369 |
buf += n; |
|
370 |
len -= n; |
|
371 |
} |
|
372 |
} |
|
373 |
while (len > 0); |
|
374 |
return 0; |
|
375 |
} |
|
376 |
||
377 |
// Complete an operation by sending the operation result and any result |
|
378 |
// output to the client. At this time the socket is in blocking mode so |
|
379 |
// potentially we can block if there is a lot of data and the client is |
|
380 |
// non-responsive. For most operations this is a non-issue because the |
|
381 |
// default send buffer is sufficient to buffer everything. In the future |
|
382 |
// if there are operations that involves a very big reply then it the |
|
383 |
// socket could be made non-blocking and a timeout could be used. |
|
384 |
||
385 |
void LinuxAttachOperation::complete(jint result, bufferedStream* st) { |
|
386 |
JavaThread* thread = JavaThread::current(); |
|
387 |
ThreadBlockInVM tbivm(thread); |
|
388 |
||
389 |
thread->set_suspend_equivalent(); |
|
390 |
// cleared by handle_special_suspend_equivalent_condition() or |
|
391 |
// java_suspend_self() via check_and_wait_while_suspended() |
|
392 |
||
393 |
// write operation result |
|
394 |
char msg[32]; |
|
395 |
sprintf(msg, "%d\n", result); |
|
396 |
int rc = LinuxAttachListener::write_fully(this->socket(), msg, strlen(msg)); |
|
397 |
||
398 |
// write any result data |
|
399 |
if (rc == 0) { |
|
400 |
LinuxAttachListener::write_fully(this->socket(), (char*) st->base(), st->size()); |
|
401 |
::shutdown(this->socket(), 2); |
|
402 |
} |
|
403 |
||
404 |
// done |
|
405 |
RESTARTABLE(::close(this->socket()), rc); |
|
406 |
||
407 |
// were we externally suspended while we were waiting? |
|
408 |
thread->check_and_wait_while_suspended(); |
|
409 |
||
410 |
delete this; |
|
411 |
} |
|
412 |
||
413 |
||
414 |
// AttachListener functions |
|
415 |
||
416 |
AttachOperation* AttachListener::dequeue() { |
|
417 |
JavaThread* thread = JavaThread::current(); |
|
418 |
ThreadBlockInVM tbivm(thread); |
|
419 |
||
420 |
thread->set_suspend_equivalent(); |
|
421 |
// cleared by handle_special_suspend_equivalent_condition() or |
|
422 |
// java_suspend_self() via check_and_wait_while_suspended() |
|
423 |
||
424 |
AttachOperation* op = LinuxAttachListener::dequeue(); |
|
425 |
||
426 |
// were we externally suspended while we were waiting? |
|
427 |
thread->check_and_wait_while_suspended(); |
|
428 |
||
429 |
return op; |
|
430 |
} |
|
431 |
||
432 |
int AttachListener::pd_init() { |
|
433 |
JavaThread* thread = JavaThread::current(); |
|
434 |
ThreadBlockInVM tbivm(thread); |
|
435 |
||
436 |
thread->set_suspend_equivalent(); |
|
437 |
// cleared by handle_special_suspend_equivalent_condition() or |
|
438 |
// java_suspend_self() via check_and_wait_while_suspended() |
|
439 |
||
440 |
int ret_code = LinuxAttachListener::init(); |
|
441 |
||
442 |
// were we externally suspended while we were waiting? |
|
443 |
thread->check_and_wait_while_suspended(); |
|
444 |
||
445 |
return ret_code; |
|
446 |
} |
|
447 |
||
448 |
// Attach Listener is started lazily except in the case when |
|
449 |
// +ReduseSignalUsage is used |
|
450 |
bool AttachListener::init_at_startup() { |
|
451 |
if (ReduceSignalUsage) { |
|
452 |
return true; |
|
453 |
} else { |
|
454 |
return false; |
|
455 |
} |
|
456 |
} |
|
457 |
||
458 |
// If the file .attach_pid<pid> exists in the working directory |
|
459 |
// or /tmp then this is the trigger to start the attach mechanism |
|
460 |
bool AttachListener::is_init_trigger() { |
|
461 |
if (init_at_startup() || is_initialized()) { |
|
462 |
return false; // initialized at startup or already initialized |
|
463 |
} |
|
5410
c4b979417733
6944822: Fix for 6938627 exposes problem with hard-coded buffer sizes
coleenp
parents:
5237
diff
changeset
|
464 |
char fn[PATH_MAX+1]; |
1 | 465 |
sprintf(fn, ".attach_pid%d", os::current_process_id()); |
466 |
int ret; |
|
467 |
struct stat64 st; |
|
468 |
RESTARTABLE(::stat64(fn, &st), ret); |
|
469 |
if (ret == -1) { |
|
5237
aab592fd4f44
6938627: Make temporary directory use property java.io.tmpdir when specified
coleenp
parents:
670
diff
changeset
|
470 |
snprintf(fn, sizeof(fn), "%s/.attach_pid%d", |
aab592fd4f44
6938627: Make temporary directory use property java.io.tmpdir when specified
coleenp
parents:
670
diff
changeset
|
471 |
os::get_temp_directory(), os::current_process_id()); |
1 | 472 |
RESTARTABLE(::stat64(fn, &st), ret); |
473 |
} |
|
474 |
if (ret == 0) { |
|
475 |
// simple check to avoid starting the attach mechanism when |
|
476 |
// a bogus user creates the file |
|
477 |
if (st.st_uid == geteuid()) { |
|
478 |
init(); |
|
479 |
return true; |
|
480 |
} |
|
481 |
} |
|
482 |
return false; |
|
483 |
} |
|
484 |
||
485 |
// if VM aborts then remove listener |
|
486 |
void AttachListener::abort() { |
|
487 |
listener_cleanup(); |
|
488 |
} |
|
489 |
||
490 |
void AttachListener::pd_data_dump() { |
|
491 |
os::signal_notify(SIGQUIT); |
|
492 |
} |
|
493 |
||
494 |
AttachOperationFunctionInfo* AttachListener::pd_find_operation(const char* n) { |
|
495 |
return NULL; |
|
496 |
} |
|
497 |
||
498 |
jint AttachListener::pd_set_flag(AttachOperation* op, outputStream* out) { |
|
499 |
out->print_cr("flag '%s' cannot be changed", op->arg(0)); |
|
500 |
return JNI_ERR; |
|
501 |
} |
|
502 |
||
503 |
void AttachListener::pd_detachall() { |
|
504 |
// do nothing for now |
|
505 |
} |