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1 | // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- |
2 | // vim: ts=8 sw=2 smarttab | |
3 | /* | |
4 | * Ceph - scalable distributed file system | |
5 | * | |
6 | * Copyright (C) 2011 New Dream Network | |
7 | * | |
8 | * This is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU Lesser General Public | |
10 | * License version 2.1, as published by the Free Software | |
11 | * Foundation. See file COPYING. | |
12 | * | |
13 | */ | |
14 | ||
15 | #include "include/int_types.h" | |
16 | ||
17 | #include "common/Thread.h" | |
18 | #include "common/OutputDataSocket.h" | |
19 | #include "common/config.h" | |
20 | #include "common/dout.h" | |
21 | #include "common/errno.h" | |
22 | #include "common/perf_counters.h" | |
23 | #include "common/pipe.h" | |
24 | #include "common/safe_io.h" | |
25 | #include "common/version.h" | |
26 | #include "common/Formatter.h" | |
27 | ||
28 | #include <errno.h> | |
29 | #include <fcntl.h> | |
30 | #include <map> | |
31 | #include <poll.h> | |
32 | #include <set> | |
33 | #include <sstream> | |
34 | #include <stdint.h> | |
35 | #include <string.h> | |
36 | #include <string> | |
37 | #include <sys/socket.h> | |
38 | #include <sys/types.h> | |
39 | #include <sys/un.h> | |
40 | #include <unistd.h> | |
41 | ||
42 | #include "include/compat.h" | |
43 | ||
44 | #define dout_subsys ceph_subsys_asok | |
45 | #undef dout_prefix | |
46 | #define dout_prefix *_dout << "asok(" << (void*)m_cct << ") " | |
47 | ||
48 | using std::ostringstream; | |
49 | ||
50 | /* | |
51 | * UNIX domain sockets created by an application persist even after that | |
52 | * application closes, unless they're explicitly unlinked. This is because the | |
53 | * directory containing the socket keeps a reference to the socket. | |
54 | * | |
55 | * This code makes things a little nicer by unlinking those dead sockets when | |
56 | * the application exits normally. | |
57 | */ | |
58 | static pthread_mutex_t cleanup_lock = PTHREAD_MUTEX_INITIALIZER; | |
59 | static std::vector <const char*> cleanup_files; | |
60 | static bool cleanup_atexit = false; | |
61 | ||
62 | static void remove_cleanup_file(const char *file) | |
63 | { | |
64 | pthread_mutex_lock(&cleanup_lock); | |
65 | VOID_TEMP_FAILURE_RETRY(unlink(file)); | |
66 | for (std::vector <const char*>::iterator i = cleanup_files.begin(); | |
67 | i != cleanup_files.end(); ++i) { | |
68 | if (strcmp(file, *i) == 0) { | |
69 | free((void*)*i); | |
70 | cleanup_files.erase(i); | |
71 | break; | |
72 | } | |
73 | } | |
74 | pthread_mutex_unlock(&cleanup_lock); | |
75 | } | |
76 | ||
77 | static void remove_all_cleanup_files() | |
78 | { | |
79 | pthread_mutex_lock(&cleanup_lock); | |
80 | for (std::vector <const char*>::iterator i = cleanup_files.begin(); | |
81 | i != cleanup_files.end(); ++i) { | |
82 | VOID_TEMP_FAILURE_RETRY(unlink(*i)); | |
83 | free((void*)*i); | |
84 | } | |
85 | cleanup_files.clear(); | |
86 | pthread_mutex_unlock(&cleanup_lock); | |
87 | } | |
88 | ||
89 | static void add_cleanup_file(const char *file) | |
90 | { | |
91 | char *fname = strdup(file); | |
92 | if (!fname) | |
93 | return; | |
94 | pthread_mutex_lock(&cleanup_lock); | |
95 | cleanup_files.push_back(fname); | |
96 | if (!cleanup_atexit) { | |
97 | atexit(remove_all_cleanup_files); | |
98 | cleanup_atexit = true; | |
99 | } | |
100 | pthread_mutex_unlock(&cleanup_lock); | |
101 | } | |
102 | ||
103 | ||
104 | OutputDataSocket::OutputDataSocket(CephContext *cct, uint64_t _backlog) | |
105 | : m_cct(cct), | |
106 | data_max_backlog(_backlog), | |
107 | m_sock_fd(-1), | |
108 | m_shutdown_rd_fd(-1), | |
109 | m_shutdown_wr_fd(-1), | |
110 | going_down(false), | |
111 | data_size(0), | |
112 | m_lock("OutputDataSocket::m_lock") | |
113 | { | |
114 | } | |
115 | ||
116 | OutputDataSocket::~OutputDataSocket() | |
117 | { | |
118 | shutdown(); | |
119 | } | |
120 | ||
121 | /* | |
122 | * This thread listens on the UNIX domain socket for incoming connections. | |
123 | * It only handles one connection at a time at the moment. All I/O is nonblocking, | |
124 | * so that we can implement sensible timeouts. [TODO: make all I/O nonblocking] | |
125 | * | |
126 | * This thread also listens to m_shutdown_rd_fd. If there is any data sent to this | |
127 | * pipe, the thread terminates itself gracefully, allowing the | |
128 | * OutputDataSocketConfigObs class to join() it. | |
129 | */ | |
130 | ||
131 | #define PFL_SUCCESS ((void*)(intptr_t)0) | |
132 | #define PFL_FAIL ((void*)(intptr_t)1) | |
133 | ||
134 | std::string OutputDataSocket::create_shutdown_pipe(int *pipe_rd, int *pipe_wr) | |
135 | { | |
136 | int pipefd[2]; | |
137 | int ret = pipe_cloexec(pipefd); | |
138 | if (ret < 0) { | |
139 | ostringstream oss; | |
140 | oss << "OutputDataSocket::create_shutdown_pipe error: " << cpp_strerror(ret); | |
141 | return oss.str(); | |
142 | } | |
143 | ||
144 | *pipe_rd = pipefd[0]; | |
145 | *pipe_wr = pipefd[1]; | |
146 | return ""; | |
147 | } | |
148 | ||
149 | std::string OutputDataSocket::bind_and_listen(const std::string &sock_path, int *fd) | |
150 | { | |
151 | ldout(m_cct, 5) << "bind_and_listen " << sock_path << dendl; | |
152 | ||
153 | struct sockaddr_un address; | |
154 | if (sock_path.size() > sizeof(address.sun_path) - 1) { | |
155 | ostringstream oss; | |
156 | oss << "OutputDataSocket::bind_and_listen: " | |
157 | << "The UNIX domain socket path " << sock_path << " is too long! The " | |
158 | << "maximum length on this system is " | |
159 | << (sizeof(address.sun_path) - 1); | |
160 | return oss.str(); | |
161 | } | |
162 | int sock_fd = socket(PF_UNIX, SOCK_STREAM, 0); | |
163 | if (sock_fd < 0) { | |
164 | int err = errno; | |
165 | ostringstream oss; | |
166 | oss << "OutputDataSocket::bind_and_listen: " | |
167 | << "failed to create socket: " << cpp_strerror(err); | |
168 | return oss.str(); | |
169 | } | |
170 | int r = fcntl(sock_fd, F_SETFD, FD_CLOEXEC); | |
171 | if (r < 0) { | |
172 | r = errno; | |
173 | VOID_TEMP_FAILURE_RETRY(::close(sock_fd)); | |
174 | ostringstream oss; | |
175 | oss << "OutputDataSocket::bind_and_listen: failed to fcntl on socket: " << cpp_strerror(r); | |
176 | return oss.str(); | |
177 | } | |
178 | memset(&address, 0, sizeof(struct sockaddr_un)); | |
179 | address.sun_family = AF_UNIX; | |
180 | snprintf(address.sun_path, sizeof(address.sun_path), | |
181 | "%s", sock_path.c_str()); | |
182 | if (::bind(sock_fd, (struct sockaddr*)&address, | |
183 | sizeof(struct sockaddr_un)) != 0) { | |
184 | int err = errno; | |
185 | if (err == EADDRINUSE) { | |
186 | // The old UNIX domain socket must still be there. | |
187 | // Let's unlink it and try again. | |
188 | VOID_TEMP_FAILURE_RETRY(unlink(sock_path.c_str())); | |
189 | if (::bind(sock_fd, (struct sockaddr*)&address, | |
190 | sizeof(struct sockaddr_un)) == 0) { | |
191 | err = 0; | |
192 | } | |
193 | else { | |
194 | err = errno; | |
195 | } | |
196 | } | |
197 | if (err != 0) { | |
198 | ostringstream oss; | |
199 | oss << "OutputDataSocket::bind_and_listen: " | |
200 | << "failed to bind the UNIX domain socket to '" << sock_path | |
201 | << "': " << cpp_strerror(err); | |
202 | close(sock_fd); | |
203 | return oss.str(); | |
204 | } | |
205 | } | |
206 | if (listen(sock_fd, 5) != 0) { | |
207 | int err = errno; | |
208 | ostringstream oss; | |
209 | oss << "OutputDataSocket::bind_and_listen: " | |
210 | << "failed to listen to socket: " << cpp_strerror(err); | |
211 | close(sock_fd); | |
212 | VOID_TEMP_FAILURE_RETRY(unlink(sock_path.c_str())); | |
213 | return oss.str(); | |
214 | } | |
215 | *fd = sock_fd; | |
216 | return ""; | |
217 | } | |
218 | ||
219 | void* OutputDataSocket::entry() | |
220 | { | |
221 | ldout(m_cct, 5) << "entry start" << dendl; | |
222 | while (true) { | |
223 | struct pollfd fds[2]; | |
224 | memset(fds, 0, sizeof(fds)); | |
225 | fds[0].fd = m_sock_fd; | |
226 | fds[0].events = POLLIN | POLLRDBAND; | |
227 | fds[1].fd = m_shutdown_rd_fd; | |
228 | fds[1].events = POLLIN | POLLRDBAND; | |
229 | ||
230 | int ret = poll(fds, 2, -1); | |
231 | if (ret < 0) { | |
232 | int err = errno; | |
233 | if (err == EINTR) { | |
234 | continue; | |
235 | } | |
236 | lderr(m_cct) << "OutputDataSocket: poll(2) error: '" | |
237 | << cpp_strerror(err) << dendl; | |
238 | return PFL_FAIL; | |
239 | } | |
240 | ||
241 | if (fds[0].revents & POLLIN) { | |
242 | // Send out some data | |
243 | do_accept(); | |
244 | } | |
245 | if (fds[1].revents & POLLIN) { | |
246 | // Parent wants us to shut down | |
247 | return PFL_SUCCESS; | |
248 | } | |
249 | } | |
250 | ldout(m_cct, 5) << "entry exit" << dendl; | |
251 | ||
252 | return PFL_SUCCESS; // unreachable | |
253 | } | |
254 | ||
255 | ||
256 | bool OutputDataSocket::do_accept() | |
257 | { | |
258 | struct sockaddr_un address; | |
259 | socklen_t address_length = sizeof(address); | |
260 | ldout(m_cct, 30) << "OutputDataSocket: calling accept" << dendl; | |
261 | int connection_fd = accept(m_sock_fd, (struct sockaddr*) &address, | |
262 | &address_length); | |
263 | ldout(m_cct, 30) << "OutputDataSocket: finished accept" << dendl; | |
264 | if (connection_fd < 0) { | |
265 | int err = errno; | |
266 | lderr(m_cct) << "OutputDataSocket: do_accept error: '" | |
267 | << cpp_strerror(err) << dendl; | |
268 | return false; | |
269 | } | |
270 | ||
271 | handle_connection(connection_fd); | |
272 | close_connection(connection_fd); | |
273 | ||
274 | return 0; | |
275 | } | |
276 | ||
277 | void OutputDataSocket::handle_connection(int fd) | |
278 | { | |
279 | bufferlist bl; | |
280 | ||
281 | m_lock.Lock(); | |
282 | init_connection(bl); | |
283 | m_lock.Unlock(); | |
284 | ||
285 | if (bl.length()) { | |
286 | /* need to special case the connection init buffer output, as it needs | |
287 | * to be dumped before any data, including older data that was sent | |
288 | * before the connection was established, or before we identified | |
289 | * older connection was broken | |
290 | */ | |
291 | int ret = safe_write(fd, bl.c_str(), bl.length()); | |
292 | if (ret < 0) { | |
293 | return; | |
294 | } | |
295 | } | |
296 | ||
297 | int ret = dump_data(fd); | |
298 | if (ret < 0) | |
299 | return; | |
300 | ||
301 | do { | |
302 | m_lock.Lock(); | |
303 | cond.Wait(m_lock); | |
304 | ||
305 | if (going_down) { | |
306 | m_lock.Unlock(); | |
307 | break; | |
308 | } | |
309 | m_lock.Unlock(); | |
310 | ||
311 | ret = dump_data(fd); | |
312 | } while (ret >= 0); | |
313 | } | |
314 | ||
315 | int OutputDataSocket::dump_data(int fd) | |
316 | { | |
317 | m_lock.Lock(); | |
318 | list<bufferlist> l; | |
319 | l = data; | |
320 | data.clear(); | |
321 | data_size = 0; | |
322 | m_lock.Unlock(); | |
323 | ||
324 | for (list<bufferlist>::iterator iter = l.begin(); iter != l.end(); ++iter) { | |
325 | bufferlist& bl = *iter; | |
326 | int ret = safe_write(fd, bl.c_str(), bl.length()); | |
327 | if (ret >= 0) { | |
328 | ret = safe_write(fd, delim.c_str(), delim.length()); | |
329 | } | |
330 | if (ret < 0) { | |
331 | for (; iter != l.end(); ++iter) { | |
332 | bufferlist& bl = *iter; | |
333 | data.push_back(bl); | |
334 | data_size += bl.length(); | |
335 | } | |
336 | return ret; | |
337 | } | |
338 | } | |
339 | ||
340 | return 0; | |
341 | } | |
342 | ||
343 | void OutputDataSocket::close_connection(int fd) | |
344 | { | |
345 | VOID_TEMP_FAILURE_RETRY(close(fd)); | |
346 | } | |
347 | ||
348 | bool OutputDataSocket::init(const std::string &path) | |
349 | { | |
350 | ldout(m_cct, 5) << "init " << path << dendl; | |
351 | ||
352 | /* Set up things for the new thread */ | |
353 | std::string err; | |
354 | int pipe_rd = -1, pipe_wr = -1; | |
355 | err = create_shutdown_pipe(&pipe_rd, &pipe_wr); | |
356 | if (!err.empty()) { | |
357 | lderr(m_cct) << "OutputDataSocketConfigObs::init: error: " << err << dendl; | |
358 | return false; | |
359 | } | |
360 | int sock_fd; | |
361 | err = bind_and_listen(path, &sock_fd); | |
362 | if (!err.empty()) { | |
363 | lderr(m_cct) << "OutputDataSocketConfigObs::init: failed: " << err << dendl; | |
364 | close(pipe_rd); | |
365 | close(pipe_wr); | |
366 | return false; | |
367 | } | |
368 | ||
369 | /* Create new thread */ | |
370 | m_sock_fd = sock_fd; | |
371 | m_shutdown_rd_fd = pipe_rd; | |
372 | m_shutdown_wr_fd = pipe_wr; | |
373 | m_path = path; | |
374 | create("out_data_socket"); | |
375 | add_cleanup_file(m_path.c_str()); | |
376 | return true; | |
377 | } | |
378 | ||
379 | void OutputDataSocket::shutdown() | |
380 | { | |
381 | m_lock.Lock(); | |
382 | going_down = true; | |
383 | cond.Signal(); | |
384 | m_lock.Unlock(); | |
385 | ||
386 | if (m_shutdown_wr_fd < 0) | |
387 | return; | |
388 | ||
389 | ldout(m_cct, 5) << "shutdown" << dendl; | |
390 | ||
391 | // Send a byte to the shutdown pipe that the thread is listening to | |
392 | char buf[1] = { 0x0 }; | |
393 | int ret = safe_write(m_shutdown_wr_fd, buf, sizeof(buf)); | |
394 | VOID_TEMP_FAILURE_RETRY(close(m_shutdown_wr_fd)); | |
395 | m_shutdown_wr_fd = -1; | |
396 | ||
397 | if (ret == 0) { | |
398 | join(); | |
399 | } else { | |
400 | lderr(m_cct) << "OutputDataSocket::shutdown: failed to write " | |
401 | "to thread shutdown pipe: error " << ret << dendl; | |
402 | } | |
403 | ||
404 | remove_cleanup_file(m_path.c_str()); | |
405 | m_path.clear(); | |
406 | } | |
407 | ||
408 | void OutputDataSocket::append_output(bufferlist& bl) | |
409 | { | |
410 | Mutex::Locker l(m_lock); | |
411 | ||
412 | if (data_size + bl.length() > data_max_backlog) { | |
413 | ldout(m_cct, 20) << "dropping data output, max backlog reached" << dendl; | |
414 | } | |
415 | data.push_back(bl); | |
416 | ||
417 | data_size += bl.length(); | |
418 | ||
419 | cond.Signal(); | |
420 | } |