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 *
25 * Copyright 2018 Joyent, Inc.
26 */
27
28 /*
29 * wait.c - asynchronous monitoring of "wait registered" start methods
30 *
31 * Use event ports to poll on the set of fds representing the /proc/[pid]/psinfo
32 * files. If one of these fds returns an event, then we inform the restarter
33 * that it has stopped.
34 *
35 * The wait_info_list holds the series of processes currently being monitored
36 * for exit. The wi_fd member, which contains the file descriptor of the psinfo
37 * file being polled upon ("event ported upon"), will be set to -1 if the file
38 * descriptor is inactive (already closed or not yet opened).
39 */
40
41 #ifdef _FILE_OFFSET_BITS
42 #undef _FILE_OFFSET_BITS
43 #endif /* _FILE_OFFSET_BITS */
44
45 #include <sys/resource.h>
46 #include <sys/stat.h>
47 #include <sys/types.h>
48 #include <sys/uio.h>
49 #include <sys/wait.h>
50
51 #include <assert.h>
52 #include <errno.h>
53 #include <fcntl.h>
54 #include <libuutil.h>
55 #include <poll.h>
56 #include <port.h>
57 #include <pthread.h>
58 #include <procfs.h>
59 #include <string.h>
60 #include <stropts.h>
61 #include <unistd.h>
62
63 #include "startd.h"
64
65 #define WAIT_FILES 262144 /* reasonably high maximum */
66
67 static int port_fd;
68 static scf_handle_t *wait_hndl;
69 static struct rlimit init_fd_rlimit;
70
71 static uu_list_pool_t *wait_info_pool;
72 static uu_list_t *wait_info_list;
73
74 static pthread_mutex_t wait_info_lock;
75
76 /*
77 * void wait_remove(wait_info_t *, int)
78 * Remove the given wait_info structure from our list, performing various
79 * cleanup operations along the way. If the direct flag is false (meaning
80 * that we are being called with from restarter instance list context) and
81 * the instance should not be ignored, then notify the restarter that the
82 * associated instance has exited. If the wi_ignore flag is true then it
83 * means that the stop was initiated from within svc.startd, rather than
84 * from outside it.
85 *
86 * Since we may no longer be the startd that started this process, we only are
87 * concerned with a waitpid(3C) failure if the wi_parent field is non-zero.
88 */
89 static void
wait_remove(wait_info_t * wi,int direct)90 wait_remove(wait_info_t *wi, int direct)
91 {
92 int status;
93 stop_cause_t cause = RSTOP_EXIT;
94
95 if (waitpid(wi->wi_pid, &status, 0) == -1) {
96 if (wi->wi_parent)
97 log_framework(LOG_INFO,
98 "instance %s waitpid failure: %s\n", wi->wi_fmri,
99 strerror(errno));
100 } else {
101 if (WEXITSTATUS(status) != 0) {
102 log_framework(LOG_NOTICE,
103 "instance %s exited with status %d\n", wi->wi_fmri,
104 WEXITSTATUS(status));
105 if (WEXITSTATUS(status) == SMF_EXIT_ERR_CONFIG)
106 cause = RSTOP_ERR_CFG;
107 else
108 cause = RSTOP_ERR_EXIT;
109 }
110 }
111
112 MUTEX_LOCK(&wait_info_lock);
113 if (wi->wi_fd != -1) {
114 startd_close(wi->wi_fd);
115 wi->wi_fd = -1;
116 }
117 uu_list_remove(wait_info_list, wi);
118 MUTEX_UNLOCK(&wait_info_lock);
119
120 /*
121 * Make an attempt to clear out any utmpx record associated with this
122 * PID.
123 */
124 utmpx_mark_dead(wi->wi_pid, status, B_FALSE);
125
126 if (!direct && !wi->wi_ignore) {
127 /*
128 * Bind wait_hndl lazily.
129 */
130 if (wait_hndl == NULL) {
131 for (wait_hndl =
132 libscf_handle_create_bound(SCF_VERSION);
133 wait_hndl == NULL;
134 wait_hndl =
135 libscf_handle_create_bound(SCF_VERSION)) {
136 log_error(LOG_INFO, "[wait_remove] Unable to "
137 "bind a new repository handle: %s\n",
138 scf_strerror(scf_error()));
139 (void) sleep(2);
140 }
141 }
142
143 log_framework(LOG_DEBUG,
144 "wait_remove requesting stop of %s\n", wi->wi_fmri);
145 (void) stop_instance_fmri(wait_hndl, wi->wi_fmri, cause);
146 }
147
148 uu_list_node_fini(wi, &wi->wi_link, wait_info_pool);
149 startd_free(wi, sizeof (wait_info_t));
150 }
151
152 /*
153 * void wait_ignore_by_fmri(const char *)
154 * wait_ignore_by_fmri is called when svc.startd is going to stop the
155 * instance. Since we need to wait on the process and close the utmpx record,
156 * we're going to set the wi_ignore flag, so that when the process exits we
157 * clean up, but don't tell the restarter to stop it.
158 */
159 void
wait_ignore_by_fmri(const char * fmri)160 wait_ignore_by_fmri(const char *fmri)
161 {
162 wait_info_t *wi;
163
164 MUTEX_LOCK(&wait_info_lock);
165
166 for (wi = uu_list_first(wait_info_list); wi != NULL;
167 wi = uu_list_next(wait_info_list, wi)) {
168 if (strcmp(wi->wi_fmri, fmri) == 0)
169 break;
170 }
171
172 if (wi != NULL) {
173 wi->wi_ignore = 1;
174 }
175
176 MUTEX_UNLOCK(&wait_info_lock);
177 }
178
179 /*
180 * int wait_register(pid_t, char *, int, int)
181 * wait_register is called after we have called fork(2), and know which pid we
182 * wish to monitor. However, since the child may have already exited by the
183 * time we are called, we must handle the error cases from open(2)
184 * appropriately. The am_parent flag is recorded to handle waitpid(2)
185 * behaviour on removal; similarly, the direct flag is passed through to a
186 * potential call to wait_remove() to govern its behaviour in different
187 * contexts.
188 *
189 * Returns 0 if registration successful, 1 if child pid did not exist, and -1
190 * if a different error occurred.
191 */
192 int
wait_register(pid_t pid,const char * inst_fmri,int am_parent,int direct)193 wait_register(pid_t pid, const char *inst_fmri, int am_parent, int direct)
194 {
195 char *fname = uu_msprintf("/proc/%ld/psinfo", pid);
196 int fd;
197 wait_info_t *wi;
198
199 assert(pid != 0);
200
201 if (fname == NULL)
202 return (-1);
203
204 wi = startd_alloc(sizeof (wait_info_t));
205
206 uu_list_node_init(wi, &wi->wi_link, wait_info_pool);
207
208 wi->wi_fd = -1;
209 wi->wi_pid = pid;
210 wi->wi_fmri = inst_fmri;
211 wi->wi_parent = am_parent;
212 wi->wi_ignore = 0;
213
214 MUTEX_LOCK(&wait_info_lock);
215 (void) uu_list_insert_before(wait_info_list, NULL, wi);
216 MUTEX_UNLOCK(&wait_info_lock);
217
218 if ((fd = open(fname, O_RDONLY)) == -1) {
219 if (errno == ENOENT) {
220 /*
221 * Child has already exited.
222 */
223 wait_remove(wi, direct);
224 uu_free(fname);
225 return (1);
226 } else {
227 log_error(LOG_WARNING,
228 "open %s failed; not monitoring %s: %s\n", fname,
229 inst_fmri, strerror(errno));
230 uu_free(fname);
231 return (-1);
232 }
233 }
234
235 uu_free(fname);
236
237 wi->wi_fd = fd;
238
239 if (port_associate(port_fd, PORT_SOURCE_FD, fd, 0, wi)) {
240 log_error(LOG_WARNING,
241 "initial port_association of %d / %s failed: %s\n", fd,
242 inst_fmri, strerror(errno));
243 return (-1);
244 }
245
246 log_framework(LOG_DEBUG, "monitoring PID %ld on fd %d (%s)\n", pid, fd,
247 inst_fmri);
248
249 return (0);
250 }
251
252 /*ARGSUSED*/
253 void *
wait_thread(void * args)254 wait_thread(void *args)
255 {
256 (void) pthread_setname_np(pthread_self(), "wait");
257
258 for (;;) {
259 port_event_t pe;
260 int fd;
261 wait_info_t *wi;
262
263 if (port_get(port_fd, &pe, NULL) != 0) {
264 if (errno == EINTR)
265 continue;
266 else {
267 log_error(LOG_WARNING,
268 "port_get() failed with %s\n",
269 strerror(errno));
270 bad_error("port_get", errno);
271 }
272 }
273
274 fd = pe.portev_object;
275 wi = pe.portev_user;
276 assert(wi != NULL);
277 assert(fd == wi->wi_fd);
278
279 if ((pe.portev_events & POLLHUP) == POLLHUP) {
280 psinfo_t psi;
281
282 if (lseek(fd, 0, SEEK_SET) != 0 ||
283 read(fd, &psi, sizeof (psinfo_t)) !=
284 sizeof (psinfo_t)) {
285 log_framework(LOG_WARNING,
286 "couldn't get psinfo data for %s (%s); "
287 "assuming failed\n", wi->wi_fmri,
288 strerror(errno));
289 goto err_remove;
290 }
291
292 if (psi.pr_nlwp != 0 ||
293 psi.pr_nzomb != 0 ||
294 psi.pr_lwp.pr_lwpid != 0) {
295 /*
296 * We have determined, in accordance with the
297 * definition in proc(5), this process is not a
298 * zombie. Reassociate.
299 */
300 if (port_associate(port_fd, PORT_SOURCE_FD, fd,
301 0, wi))
302 log_error(LOG_WARNING,
303 "port_association of %d / %s "
304 "failed\n", fd, wi->wi_fmri);
305 continue;
306 }
307 } else if (
308 (pe.portev_events & POLLERR) == 0) {
309 if (port_associate(port_fd, PORT_SOURCE_FD, fd, 0, wi))
310 log_error(LOG_WARNING,
311 "port_association of %d / %s "
312 "failed\n", fd, wi->wi_fmri);
313 continue;
314 }
315
316 err_remove:
317 wait_remove(wi, 0);
318 }
319
320 /*LINTED E_FUNC_HAS_NO_RETURN_STMT*/
321 }
322
323 void
wait_prefork()324 wait_prefork()
325 {
326 MUTEX_LOCK(&wait_info_lock);
327 }
328
329 void
wait_postfork(pid_t pid)330 wait_postfork(pid_t pid)
331 {
332 wait_info_t *wi;
333
334 MUTEX_UNLOCK(&wait_info_lock);
335
336 if (pid != 0)
337 return;
338
339 /*
340 * Close all of the child's wait-related fds. The wait_thread() is
341 * gone, so no need to worry about returning events. We always exec(2)
342 * after a fork request, so we needn't free the list elements
343 * themselves.
344 */
345
346 for (wi = uu_list_first(wait_info_list);
347 wi != NULL;
348 wi = uu_list_next(wait_info_list, wi)) {
349 if (wi->wi_fd != -1)
350 startd_close(wi->wi_fd);
351 }
352
353 startd_close(port_fd);
354
355 (void) setrlimit(RLIMIT_NOFILE, &init_fd_rlimit);
356 }
357
358 void
wait_init()359 wait_init()
360 {
361 struct rlimit fd_new;
362
363 (void) getrlimit(RLIMIT_NOFILE, &init_fd_rlimit);
364 (void) getrlimit(RLIMIT_NOFILE, &fd_new);
365
366 fd_new.rlim_max = fd_new.rlim_cur = WAIT_FILES;
367
368 (void) setrlimit(RLIMIT_NOFILE, &fd_new);
369
370 if ((port_fd = port_create()) == -1)
371 uu_die("wait_init couldn't port_create");
372
373 wait_info_pool = uu_list_pool_create("wait_info", sizeof (wait_info_t),
374 offsetof(wait_info_t, wi_link), NULL, UU_LIST_POOL_DEBUG);
375 if (wait_info_pool == NULL)
376 uu_die("wait_init couldn't create wait_info_pool");
377
378 wait_info_list = uu_list_create(wait_info_pool, wait_info_list, 0);
379 if (wait_info_list == NULL)
380 uu_die("wait_init couldn't create wait_info_list");
381
382 (void) pthread_mutex_init(&wait_info_lock, &mutex_attrs);
383 }
384