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      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, Version 1.0 only
      6  * (the "License").  You may not use this file except in compliance
      7  * with the License.
      8  *
      9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
     10  * or http://www.opensolaris.org/os/licensing.
     11  * See the License for the specific language governing permissions
     12  * and limitations under the License.
     13  *
     14  * When distributing Covered Code, include this CDDL HEADER in each
     15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
     16  * If applicable, add the following below this CDDL HEADER, with the
     17  * fields enclosed by brackets "[]" replaced with your own identifying
     18  * information: Portions Copyright [yyyy] [name of copyright owner]
     19  *
     20  * CDDL HEADER END
     21  */
     22 /*
     23  * Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
     24  * Use is subject to license terms.
     25  */
     26 
     27 #pragma ident	"%Z%%M%	%I%	%E% SMI"
     28 
     29 #include <stdio.h>
     30 #include <stdlib.h>
     31 #include <unistd.h>
     32 #include <fcntl.h>
     33 #include <ctype.h>
     34 #include <string.h>
     35 #include <signal.h>
     36 #include <errno.h>
     37 #include <sys/types.h>
     38 #include <sys/wait.h>
     39 #include <libproc.h>
     40 
     41 #define	NOREAP_TIME 60		/* wait 60 seconds before allow a reap */
     42 
     43 static volatile int interrupt;
     44 static int Fflag;
     45 static char *command;
     46 
     47 static void
     48 intr(int sig)
     49 {
     50 	interrupt = sig;
     51 }
     52 
     53 static int
     54 open_usage(pid_t pid, int *perr)
     55 {
     56 	char path[64];
     57 	struct stat64 st;
     58 	int fd;
     59 
     60 	(void) snprintf(path, sizeof (path), "/proc/%d/usage", (int)pid);
     61 
     62 	/*
     63 	 * Attempt to open the usage file, and return the fd if we can
     64 	 * confirm this is a regular file provided by /proc.
     65 	 */
     66 	if ((fd = open64(path, O_RDONLY)) >= 0) {
     67 		if (fstat64(fd, &st) != 0 || !S_ISREG(st.st_mode) ||
     68 		    strcmp(st.st_fstype, "proc") != 0) {
     69 			(void) close(fd);
     70 			fd = -1;
     71 		}
     72 	} else if (errno == EACCES || errno == EPERM)
     73 		*perr = G_PERM;
     74 
     75 	return (fd);
     76 }
     77 
     78 static int
     79 proc_usage(pid_t pid, prusage_t *pup, int *perr)
     80 {
     81 	int fd;
     82 
     83 	*perr = G_NOPROC;
     84 
     85 	if ((fd = open_usage(pid, perr)) != -1) {
     86 		if (read(fd, pup, sizeof (prusage_t)) == sizeof (prusage_t)) {
     87 			*perr = 0;
     88 			(void) close(fd);
     89 			return (0);
     90 		}
     91 
     92 		/*
     93 		 * If the read failed, the process may have gone away.
     94 		 */
     95 		(void) close(fd);
     96 	}
     97 	return (-1);
     98 }
     99 
    100 /*
    101  * Force the parent process (ppid) to wait for its child process (pid).
    102  */
    103 static int
    104 reap(char *arg, pid_t *reap_pid, int *exit_status)
    105 {
    106 	struct ps_prochandle *Pr;
    107 	siginfo_t siginfo;
    108 	psinfo_t psinfo;
    109 	prusage_t usage;
    110 	pid_t pid, ppid;
    111 	time_t elapsed;
    112 	int gret;
    113 
    114 	/*
    115 	 * get the specified pid and the psinfo struct
    116 	 */
    117 	if ((pid = proc_arg_psinfo(arg, PR_ARG_PIDS, &psinfo, &gret)) == -1) {
    118 		(void) fprintf(stderr, "%s: cannot examine %s: %s\n",
    119 		    command, arg, Pgrab_error(gret));
    120 		return (1);
    121 	}
    122 
    123 	if (psinfo.pr_nlwp != 0) {
    124 		(void) fprintf(stderr, "%s: process not defunct: %d\n",
    125 		    command, (int)pid);
    126 		return (1);
    127 	}
    128 
    129 	*exit_status = psinfo.pr_wstat;
    130 	*reap_pid = psinfo.pr_pid;
    131 	ppid = psinfo.pr_ppid;
    132 
    133 	if (ppid == 1) {
    134 		(void) fprintf(stderr, "%s: Failed to reap %d: the only "
    135 		    "non-defunct ancestor is 'init'\n", command,
    136 		    (int)pid);
    137 		return (1);
    138 	}
    139 
    140 	if (proc_usage(pid, &usage, &gret) == 0) {
    141 		elapsed = usage.pr_tstamp.tv_sec - usage.pr_term.tv_sec;
    142 	} else {
    143 		(void) fprintf(stderr, "%s: cannot examine %d: %s\n",
    144 		    command, (int)pid, Pgrab_error(gret));
    145 		return (1);
    146 	}
    147 
    148 	if ((Fflag == 0) && (elapsed < NOREAP_TIME)) {
    149 		(void) fprintf(stderr, "%s: unsafe to reap %d; it has been "
    150 		    "defunct less than %d seconds\n", command, (int)pid,
    151 		    NOREAP_TIME);
    152 		return (1);
    153 	}
    154 
    155 	if ((Pr = Pgrab(ppid, Fflag | PGRAB_NOSTOP, &gret)) == NULL) {
    156 		(void) fprintf(stderr, "%s: cannot examine %d: %s\n", command,
    157 		    (int)ppid, Pgrab_error(gret));
    158 		return (1);
    159 	}
    160 
    161 	if ((Fflag == 0) && (Pstate(Pr) == PS_STOP)) {
    162 		Prelease(Pr, 0);
    163 		(void) fprintf(stderr, "%s: unsafe to reap %d; parent is "
    164 		    "stopped and may reap status upon restart\n", command,
    165 		    (int)pid);
    166 		return (1);
    167 	}
    168 
    169 	/*
    170 	 * Pstop() will fail if the process to be stopped has become a zombie.
    171 	 * This means that we can say with certainty that the child of this
    172 	 * process has not changed parents (i.e. been reparented to init) once
    173 	 * the Pstop() succeeds.
    174 	 */
    175 	if (Pstop(Pr, 1000) != 0) {
    176 		Prelease(Pr, 0);
    177 		(void) fprintf(stderr, "%s: failed to stop %d: %s", command,
    178 		    (int)ppid, strerror(errno));
    179 		return (1);
    180 	}
    181 
    182 	if (pr_waitid(Pr, P_PID, pid, &siginfo, WEXITED|WNOHANG) != 0) {
    183 		Prelease(Pr, 0);
    184 		(void) fprintf(stderr, "%s: waitid() in process %d failed: %s",
    185 		    command, (int)ppid, strerror(errno));
    186 		return (1);
    187 	}
    188 
    189 	Prelease(Pr, 0);
    190 	return (0);
    191 }
    192 
    193 static void
    194 print_exit_status(pid_t pid, int wstat)
    195 {
    196 	(void) printf("%d: ", (int)pid);
    197 	if (WIFSIGNALED(wstat)) {
    198 		char buf[SIG2STR_MAX];
    199 		int sig = WTERMSIG(wstat);
    200 
    201 		if (sig2str(sig, buf) == 0)
    202 			(void) printf("killed by signal %s", buf);
    203 		else
    204 			(void) printf("killed by signal %d", sig);
    205 
    206 		if (WCOREDUMP(wstat))
    207 			(void) printf(" (core dumped)");
    208 	} else {
    209 		(void) printf("exited with status %d", WEXITSTATUS(wstat));
    210 	}
    211 	(void) printf("\n");
    212 }
    213 
    214 int
    215 main(int argc, char *argv[])
    216 {
    217 	int retc = 0;
    218 	int opt;
    219 	int errflg = 0;
    220 
    221 	if ((command = strrchr(argv[0], '/')) != NULL)
    222 		command++;
    223 	else
    224 		command = argv[0];
    225 
    226 	while ((opt = getopt(argc, argv, "F")) != EOF) {
    227 		switch (opt) {
    228 		case 'F':		/* force grabbing (no O_EXCL) */
    229 			Fflag = PGRAB_FORCE;
    230 			break;
    231 		default:
    232 			errflg = 1;
    233 			break;
    234 		}
    235 	}
    236 
    237 	argc -= optind;
    238 	argv += optind;
    239 
    240 	if (errflg || argc <= 0) {
    241 		(void) fprintf(stderr, "usage:  %s pid ...\n", command);
    242 		(void) fprintf(stderr, "  (Reap a defunct process by forcing "
    243 		    "its parent to wait(2) for it)\n");
    244 		exit(2);
    245 	}
    246 
    247 	/* catch signals from terminal */
    248 	if (sigset(SIGHUP, SIG_IGN) == SIG_DFL)
    249 		(void) sigset(SIGHUP, intr);
    250 	if (sigset(SIGINT, SIG_IGN) == SIG_DFL)
    251 		(void) sigset(SIGINT, intr);
    252 	if (sigset(SIGPIPE, SIG_IGN) == SIG_DFL)
    253 		(void) sigset(SIGPIPE, intr);
    254 	if (sigset(SIGQUIT, SIG_IGN) == SIG_DFL)
    255 		(void) sigset(SIGQUIT, intr);
    256 	(void) sigset(SIGTERM, intr);
    257 
    258 	while (--argc >= 0 && !interrupt) {
    259 		pid_t pid;
    260 		int wstat, r;
    261 
    262 		retc += r = reap(*argv++, &pid, &wstat);
    263 
    264 		if (r == 0)
    265 			print_exit_status(pid, wstat);
    266 	}
    267 
    268 	if (interrupt && retc == 0)
    269 		retc++;
    270 	return (retc == 0 ? 0 : 1);
    271 }
    272