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/*
* This file is part of the ZFS Event Daemon (ZED)
* for ZFS on Linux (ZoL) <http://zfsonlinux.org/>.
* Developed at Lawrence Livermore National Laboratory (LLNL-CODE-403049).
* Copyright (C) 2013-2014 Lawrence Livermore National Security, LLC.
* Refer to the ZoL git commit log for authoritative copyright attribution.
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License Version 1.0 (CDDL-1.0).
* You can obtain a copy of the license from the top-level file
* "OPENSOLARIS.LICENSE" or at <http://opensource.org/licenses/CDDL-1.0>.
* You may not use this file except in compliance with the license.
*/
#include <assert.h>
#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <time.h>
#include <unistd.h>
#include "zed_exec.h"
#include "zed_file.h"
#include "zed_log.h"
#include "zed_strings.h"
#define ZEVENT_FILENO 3
/*
* Create an environment string array for passing to execve() using the
* NAME=VALUE strings in container [zsp].
* Return a newly-allocated environment, or NULL on error.
*/
static char **
_zed_exec_create_env(zed_strings_t *zsp)
{
int num_ptrs;
int buflen;
char *buf;
char **pp;
char *p;
const char *q;
int i;
int len;
num_ptrs = zed_strings_count(zsp) + 1;
buflen = num_ptrs * sizeof (char *);
for (q = zed_strings_first(zsp); q; q = zed_strings_next(zsp))
buflen += strlen(q) + 1;
buf = calloc(1, buflen);
if (!buf)
return (NULL);
pp = (char **)buf;
p = buf + (num_ptrs * sizeof (char *));
i = 0;
for (q = zed_strings_first(zsp); q; q = zed_strings_next(zsp)) {
pp[i] = p;
len = strlen(q) + 1;
memcpy(p, q, len);
p += len;
i++;
}
pp[i] = NULL;
assert(buf + buflen == p);
return ((char **)buf);
}
/*
* Fork a child process to handle event [eid]. The program [prog]
* in directory [dir] is executed with the environment [env].
*
* The file descriptor [zfd] is the zevent_fd used to track the
* current cursor location within the zevent nvlist.
*/
static void
_zed_exec_fork_child(uint64_t eid, const char *dir, const char *prog,
char *env[], int zfd)
{
char path[PATH_MAX];
int n;
pid_t pid;
int fd;
pid_t wpid;
int status;
assert(dir != NULL);
assert(prog != NULL);
assert(env != NULL);
assert(zfd >= 0);
n = snprintf(path, sizeof (path), "%s/%s", dir, prog);
if ((n < 0) || (n >= sizeof (path))) {
zed_log_msg(LOG_WARNING,
"Failed to fork \"%s\" for eid=%llu: %s",
prog, eid, strerror(ENAMETOOLONG));
return;
}
pid = fork();
if (pid < 0) {
zed_log_msg(LOG_WARNING,
"Failed to fork \"%s\" for eid=%llu: %s",
prog, eid, strerror(errno));
return;
} else if (pid == 0) {
(void) umask(022);
if ((fd = open("/dev/null", O_RDWR)) != -1) {
(void) dup2(fd, STDIN_FILENO);
(void) dup2(fd, STDOUT_FILENO);
(void) dup2(fd, STDERR_FILENO);
}
(void) dup2(zfd, ZEVENT_FILENO);
zed_file_close_from(ZEVENT_FILENO + 1);
execle(path, prog, NULL, env);
_exit(127);
}
/* parent process */
zed_log_msg(LOG_INFO, "Invoking \"%s\" eid=%llu pid=%d",
prog, eid, pid);
/* FIXME: Timeout rogue child processes with sigalarm? */
/*
* Wait for child process using WNOHANG to limit
* the time spent waiting to 10 seconds (10,000ms).
*/
for (n = 0; n < 1000; n++) {
wpid = waitpid(pid, &status, WNOHANG);
if (wpid == (pid_t)-1) {
if (errno == EINTR)
continue;
zed_log_msg(LOG_WARNING,
"Failed to wait for \"%s\" eid=%llu pid=%d",
prog, eid, pid);
break;
} else if (wpid == 0) {
struct timespec t;
/* child still running */
t.tv_sec = 0;
t.tv_nsec = 10000000; /* 10ms */
(void) nanosleep(&t, NULL);
continue;
}
if (WIFEXITED(status)) {
zed_log_msg(LOG_INFO,
"Finished \"%s\" eid=%llu pid=%d exit=%d",
prog, eid, pid, WEXITSTATUS(status));
} else if (WIFSIGNALED(status)) {
zed_log_msg(LOG_INFO,
"Finished \"%s\" eid=%llu pid=%d sig=%d/%s",
prog, eid, pid, WTERMSIG(status),
strsignal(WTERMSIG(status)));
} else {
zed_log_msg(LOG_INFO,
"Finished \"%s\" eid=%llu pid=%d status=0x%X",
prog, eid, (unsigned int) status);
}
break;
}
/*
* kill child process after 10 seconds
*/
if (wpid == 0) {
zed_log_msg(LOG_WARNING, "Killing hung \"%s\" pid=%d",
prog, pid);
(void) kill(pid, SIGKILL);
}
}
/*
* Process the event [eid] by synchronously invoking all zedlets with a
* matching class prefix.
*
* Each executable in [zedlets] from the directory [dir] is matched against
* the event's [class], [subclass], and the "all" class (which matches
* all events). Every zedlet with a matching class prefix is invoked.
* The NAME=VALUE strings in [envs] will be passed to the zedlet as
* environment variables.
*
* The file descriptor [zfd] is the zevent_fd used to track the
* current cursor location within the zevent nvlist.
*
* Return 0 on success, -1 on error.
*/
int
zed_exec_process(uint64_t eid, const char *class, const char *subclass,
const char *dir, zed_strings_t *zedlets, zed_strings_t *envs, int zfd)
{
const char *class_strings[4];
const char *allclass = "all";
const char **csp;
const char *z;
char **e;
int n;
if (!dir || !zedlets || !envs || zfd < 0)
return (-1);
csp = class_strings;
if (class)
*csp++ = class;
if (subclass)
*csp++ = subclass;
if (allclass)
*csp++ = allclass;
*csp = NULL;
e = _zed_exec_create_env(envs);
for (z = zed_strings_first(zedlets); z; z = zed_strings_next(zedlets)) {
for (csp = class_strings; *csp; csp++) {
n = strlen(*csp);
if ((strncmp(z, *csp, n) == 0) && !isalpha(z[n]))
_zed_exec_fork_child(eid, dir, z, e, zfd);
}
}
free(e);
return (0);
}
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