1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21 /*
22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
24 * Copyright 2012, Joyent, Inc. All rights reserved.
25 */
26
27 /*
28 * wait.c - asynchronous monitoring of "wait registered" start methods
29 *
30 * Use event ports to poll on the set of fds representing the /proc/[pid]/psinfo
31 * files. If one of these fds returns an event, then we inform the restarter
32 * that it has stopped.
33 *
34 * The wait_info_list holds the series of processes currently being monitored
35 * for exit. The wi_fd member, which contains the file descriptor of the psinfo
36 * file being polled upon ("event ported upon"), will be set to -1 if the file
37 * descriptor is inactive (already closed or not yet opened).
38 */
39
40 #ifdef _FILE_OFFSET_BITS
41 #undef _FILE_OFFSET_BITS
42 #endif /* _FILE_OFFSET_BITS */
43
44 #include <sys/resource.h>
45 #include <sys/stat.h>
46 #include <sys/types.h>
47 #include <sys/uio.h>
48 #include <sys/wait.h>
49
50 #include <assert.h>
51 #include <errno.h>
52 #include <fcntl.h>
53 #include <libuutil.h>
54 #include <poll.h>
55 #include <port.h>
56 #include <pthread.h>
57 #include <procfs.h>
58 #include <string.h>
59 #include <stropts.h>
60 #include <unistd.h>
61
62 #include "startd.h"
63
64 #define WAIT_FILES 262144 /* reasonably high maximum */
65
66 static int port_fd;
67 static scf_handle_t *wait_hndl;
68 static struct rlimit init_fd_rlimit;
69
70 static uu_list_pool_t *wait_info_pool;
71 static uu_list_t *wait_info_list;
72
73 static pthread_mutex_t wait_info_lock;
74
75 /*
76 * void wait_remove(wait_info_t *, int)
77 * Remove the given wait_info structure from our list, performing various
78 * cleanup operations along the way. If the direct flag is false (meaning
79 * that we are being called with from restarter instance list context) and
80 * the instance should not be ignored, then notify the restarter that the
81 * associated instance has exited. If the wi_ignore flag is true then it
82 * means that the stop was initiated from within svc.startd, rather than
83 * from outside it.
84 *
85 * Since we may no longer be the startd that started this process, we only are
86 * concerned with a waitpid(3C) failure if the wi_parent field is non-zero.
87 */
88 static void
89 wait_remove(wait_info_t *wi, int direct)
90 {
91 int status;
92 stop_cause_t cause = RSTOP_EXIT;
93
94 if (waitpid(wi->wi_pid, &status, 0) == -1) {
95 if (wi->wi_parent)
96 log_framework(LOG_INFO,
97 "instance %s waitpid failure: %s\n", wi->wi_fmri,
98 strerror(errno));
99 } else {
100 if (WEXITSTATUS(status) != 0) {
101 log_framework(LOG_NOTICE,
102 "instance %s exited with status %d\n", wi->wi_fmri,
103 WEXITSTATUS(status));
104 if (WEXITSTATUS(status) == SMF_EXIT_ERR_CONFIG)
105 cause = RSTOP_ERR_CFG;
106 else
107 cause = RSTOP_ERR_EXIT;
108 }
109 }
110
111 MUTEX_LOCK(&wait_info_lock);
112 if (wi->wi_fd != -1) {
113 startd_close(wi->wi_fd);
114 wi->wi_fd = -1;
115 }
116 uu_list_remove(wait_info_list, wi);
117 MUTEX_UNLOCK(&wait_info_lock);
118
119 /*
120 * Make an attempt to clear out any utmpx record associated with this
121 * PID.
122 */
123 utmpx_mark_dead(wi->wi_pid, status, B_FALSE);
124
125 if (!direct && !wi->wi_ignore) {
126 /*
127 * Bind wait_hndl lazily.
128 */
129 if (wait_hndl == NULL) {
130 for (wait_hndl =
131 libscf_handle_create_bound(SCF_VERSION);
132 wait_hndl == NULL;
133 wait_hndl =
134 libscf_handle_create_bound(SCF_VERSION)) {
135 log_error(LOG_INFO, "[wait_remove] Unable to "
136 "bind a new repository handle: %s\n",
137 scf_strerror(scf_error()));
138 (void) sleep(2);
139 }
140 }
141
142 log_framework(LOG_DEBUG,
143 "wait_remove requesting stop of %s\n", wi->wi_fmri);
144 (void) stop_instance_fmri(wait_hndl, wi->wi_fmri, cause);
145 }
146
147 uu_list_node_fini(wi, &wi->wi_link, wait_info_pool);
148 startd_free(wi, sizeof (wait_info_t));
149 }
150
151 /*
152 * void wait_ignore_by_fmri(const char *)
153 * wait_ignore_by_fmri is called when svc.startd is going to stop the
154 * instance. Since we need to wait on the process and close the utmpx record,
155 * we're going to set the wi_ignore flag, so that when the process exits we
156 * clean up, but don't tell the restarter to stop it.
157 */
158 void
159 wait_ignore_by_fmri(const char *fmri)
160 {
161 wait_info_t *wi;
162
163 MUTEX_LOCK(&wait_info_lock);
164
165 for (wi = uu_list_first(wait_info_list); wi != NULL;
166 wi = uu_list_next(wait_info_list, wi)) {
167 if (strcmp(wi->wi_fmri, fmri) == 0)
168 break;
169 }
170
171 if (wi != NULL) {
172 wi->wi_ignore = 1;
173 }
174
175 MUTEX_UNLOCK(&wait_info_lock);
176 }
177
178 /*
179 * int wait_register(pid_t, char *, int, int)
180 * wait_register is called after we have called fork(2), and know which pid we
181 * wish to monitor. However, since the child may have already exited by the
182 * time we are called, we must handle the error cases from open(2)
183 * appropriately. The am_parent flag is recorded to handle waitpid(2)
184 * behaviour on removal; similarly, the direct flag is passed through to a
185 * potential call to wait_remove() to govern its behaviour in different
186 * contexts.
187 *
188 * Returns 0 if registration successful, 1 if child pid did not exist, and -1
189 * if a different error occurred.
190 */
191 int
192 wait_register(pid_t pid, const char *inst_fmri, int am_parent, int direct)
193 {
194 char *fname = uu_msprintf("/proc/%ld/psinfo", pid);
195 int fd;
196 wait_info_t *wi;
197
198 assert(pid != 0);
199
200 if (fname == NULL)
201 return (-1);
202
203 wi = startd_alloc(sizeof (wait_info_t));
204
205 uu_list_node_init(wi, &wi->wi_link, wait_info_pool);
206
207 wi->wi_fd = -1;
208 wi->wi_pid = pid;
209 wi->wi_fmri = inst_fmri;
210 wi->wi_parent = am_parent;
211 wi->wi_ignore = 0;
212
213 MUTEX_LOCK(&wait_info_lock);
214 (void) uu_list_insert_before(wait_info_list, NULL, wi);
215 MUTEX_UNLOCK(&wait_info_lock);
216
217 if ((fd = open(fname, O_RDONLY)) == -1) {
218 if (errno == ENOENT) {
219 /*
220 * Child has already exited.
221 */
222 wait_remove(wi, direct);
223 uu_free(fname);
224 return (1);
225 } else {
226 log_error(LOG_WARNING,
227 "open %s failed; not monitoring %s: %s\n", fname,
228 inst_fmri, strerror(errno));
229 uu_free(fname);
230 return (-1);
231 }
232 }
233
234 uu_free(fname);
235
236 wi->wi_fd = fd;
237
238 if (port_associate(port_fd, PORT_SOURCE_FD, fd, 0, wi)) {
239 log_error(LOG_WARNING,
240 "initial port_association of %d / %s failed: %s\n", fd,
241 inst_fmri, strerror(errno));
242 return (-1);
243 }
244
245 log_framework(LOG_DEBUG, "monitoring PID %ld on fd %d (%s)\n", pid, fd,
246 inst_fmri);
247
248 return (0);
249 }
250
251 /*ARGSUSED*/
252 void *
253 wait_thread(void *args)
254 {
255 for (;;) {
256 port_event_t pe;
257 int fd;
258 wait_info_t *wi;
259
260 if (port_get(port_fd, &pe, NULL) != 0) {
261 if (errno == EINTR)
262 continue;
263 else {
264 log_error(LOG_WARNING,
265 "port_get() failed with %s\n",
266 strerror(errno));
267 bad_error("port_get", errno);
268 }
269 }
270
271 fd = pe.portev_object;
272 wi = pe.portev_user;
273 assert(wi != NULL);
274 assert(fd == wi->wi_fd);
275
276 if ((pe.portev_events & POLLHUP) == POLLHUP) {
277 psinfo_t psi;
278
279 if (lseek(fd, 0, SEEK_SET) != 0 ||
280 read(fd, &psi, sizeof (psinfo_t)) !=
281 sizeof (psinfo_t)) {
282 log_framework(LOG_WARNING,
283 "couldn't get psinfo data for %s (%s); "
284 "assuming failed\n", wi->wi_fmri,
285 strerror(errno));
286 goto err_remove;
287 }
288
289 if (psi.pr_nlwp != 0 ||
290 psi.pr_nzomb != 0 ||
291 psi.pr_lwp.pr_lwpid != 0) {
292 /*
293 * We have determined, in accordance with the
294 * definition in proc(4), this process is not a
295 * zombie. Reassociate.
296 */
297 if (port_associate(port_fd, PORT_SOURCE_FD, fd,
298 0, wi))
299 log_error(LOG_WARNING,
300 "port_association of %d / %s "
301 "failed\n", fd, wi->wi_fmri);
302 continue;
303 }
304 } else if (
305 (pe.portev_events & POLLERR) == 0) {
306 if (port_associate(port_fd, PORT_SOURCE_FD, fd, 0, wi))
307 log_error(LOG_WARNING,
308 "port_association of %d / %s "
309 "failed\n", fd, wi->wi_fmri);
310 continue;
311 }
312
313 err_remove:
314 wait_remove(wi, 0);
315 }
316
317 /*LINTED E_FUNC_HAS_NO_RETURN_STMT*/
318 }
319
320 void
321 wait_prefork()
322 {
323 MUTEX_LOCK(&wait_info_lock);
324 }
325
326 void
327 wait_postfork(pid_t pid)
328 {
329 wait_info_t *wi;
330
331 MUTEX_UNLOCK(&wait_info_lock);
332
333 if (pid != 0)
334 return;
335
336 /*
337 * Close all of the child's wait-related fds. The wait_thread() is
338 * gone, so no need to worry about returning events. We always exec(2)
339 * after a fork request, so we needn't free the list elements
340 * themselves.
341 */
342
343 for (wi = uu_list_first(wait_info_list);
344 wi != NULL;
345 wi = uu_list_next(wait_info_list, wi)) {
346 if (wi->wi_fd != -1)
347 startd_close(wi->wi_fd);
348 }
349
350 startd_close(port_fd);
351
352 (void) setrlimit(RLIMIT_NOFILE, &init_fd_rlimit);
353 }
354
355 void
356 wait_init()
357 {
358 struct rlimit fd_new;
359
360 (void) getrlimit(RLIMIT_NOFILE, &init_fd_rlimit);
361 (void) getrlimit(RLIMIT_NOFILE, &fd_new);
362
363 fd_new.rlim_max = fd_new.rlim_cur = WAIT_FILES;
364
365 (void) setrlimit(RLIMIT_NOFILE, &fd_new);
366
367 if ((port_fd = port_create()) == -1)
368 uu_die("wait_init couldn't port_create");
369
370 wait_info_pool = uu_list_pool_create("wait_info", sizeof (wait_info_t),
371 offsetof(wait_info_t, wi_link), NULL, UU_LIST_POOL_DEBUG);
372 if (wait_info_pool == NULL)
373 uu_die("wait_init couldn't create wait_info_pool");
374
375 wait_info_list = uu_list_create(wait_info_pool, wait_info_list, 0);
376 if (wait_info_list == NULL)
377 uu_die("wait_init couldn't create wait_info_list");
378
379 (void) pthread_mutex_init(&wait_info_lock, &mutex_attrs);
380 }