1 files changed, 405 insertions, 0 deletions
diff --git a/lib/utils_cmd.c b/lib/utils_cmd.c
new file mode 100644
index 0000000..cfb2073
--- /dev/null
+++ b/lib/utils_cmd.c
@@ -0,0 +1,405 @@
+/*****************************************************************************
+*
+* Monitoring run command utilities
+*
+* License: GPL
+* Copyright (c) 2005-2006 Monitoring Plugins Development Team
+*
+* Description :
+*
+* A simple interface to executing programs from other programs, using an
+* optimized and safe popen()-like implementation. It is considered safe
+* in that no shell needs to be spawned and the environment passed to the
+* execve()'d program is essentially empty.
+*
+* The code in this file is a derivative of popen.c which in turn was taken
+* from "Advanced Programming for the Unix Environment" by W. Richard Stevens.
+*
+* Care has been taken to make sure the functions are async-safe. The one
+* function which isn't is cmd_init() which it doesn't make sense to
+* call twice anyway, so the api as a whole should be considered async-safe.
+*
+*
+* This program is free software: you can redistribute it and/or modify
+* it under the terms of the GNU General Public License as published by
+* the Free Software Foundation, either version 3 of the License, or
+* (at your option) any later version.
+*
+* This program is distributed in the hope that it will be useful,
+* but WITHOUT ANY WARRANTY; without even the implied warranty of
+* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+* GNU General Public License for more details.
+*
+* You should have received a copy of the GNU General Public License
+* along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*
+*
+*****************************************************************************/
+
+#define NAGIOSPLUG_API_C 1
+
+/** includes **/
+#include "common.h"
+#include "utils.h"
+#include "utils_cmd.h"
+/* This variable must be global, since there's no way the caller
+ * can forcibly slay a dead or ungainly running program otherwise.
+ * Multithreading apps and plugins can initialize it (via CMD_INIT)
+ * in an async safe manner PRIOR to calling cmd_run() or cmd_run_array()
+ * for the first time.
+ *
+ * The check for initialized values is atomic and can
+ * occur in any number of threads simultaneously. */
+static pid_t *_cmd_pids = NULL;
+
+#include "utils_base.h"
+
+#include "./maxfd.h"
+
+#include <fcntl.h>
+
+#ifdef HAVE_SYS_WAIT_H
+# include <sys/wait.h>
+#endif
+
+/* used in _cmd_open to pass the environment to commands */
+extern char **environ;
+
+/** macros **/
+#ifndef WEXITSTATUS
+# define WEXITSTATUS(stat_val) ((unsigned)(stat_val) >> 8)
+#endif
+
+#ifndef WIFEXITED
+# define WIFEXITED(stat_val) (((stat_val) & 255) == 0)
+#endif
+
+/* 4.3BSD Reno <signal.h> doesn't define SIG_ERR */
+#if defined(SIG_IGN) && !defined(SIG_ERR)
+# define SIG_ERR ((Sigfunc *)-1)
+#endif
+
+/** prototypes **/
+static int _cmd_open (char *const *, int *, int *)
+	__attribute__ ((__nonnull__ (1, 2, 3)));
+
+static int _cmd_fetch_output (int, output *, int)
+	__attribute__ ((__nonnull__ (2)));
+
+static int _cmd_close (int);
+
+/* prototype imported from utils.h */
+extern void die (int, const char *, ...)
+	__attribute__ ((__noreturn__, __format__ (__printf__, 2, 3)));
+
+
+/* this function is NOT async-safe. It is exported so multithreaded
+ * plugins (or other apps) can call it prior to running any commands
+ * through this api and thus achieve async-safeness throughout the api */
+void
+cmd_init (void)
+{
+	long maxfd = mp_open_max();
+
+	/* if maxfd is unnaturally high, we force it to a lower value
+	 * ( e.g. on SunOS, when ulimit is set to unlimited: 2147483647 this would cause
+	 * a segfault when following calloc is called ...  ) */
+
+	if ( maxfd > MAXFD_LIMIT ) {
+		maxfd = MAXFD_LIMIT;
+	}
+
+	if (!_cmd_pids)
+		_cmd_pids = calloc (maxfd, sizeof (pid_t));
+}
+
+
+/* Start running a command, array style */
+static int
+_cmd_open (char *const *argv, int *pfd, int *pfderr)
+{
+	pid_t pid;
+#ifdef RLIMIT_CORE
+	struct rlimit limit;
+#endif
+
+	int i = 0;
+
+	if (!_cmd_pids)
+		CMD_INIT;
+
+	setenv("LC_ALL", "C", 1);
+
+	if (pipe (pfd) < 0 || pipe (pfderr) < 0 || (pid = fork ()) < 0)
+		return -1;									/* errno set by the failing function */
+
+	/* child runs exceve() and _exit. */
+	if (pid == 0) {
+#ifdef 	RLIMIT_CORE
+		/* the program we execve shouldn't leave core files */
+		getrlimit (RLIMIT_CORE, &limit);
+		limit.rlim_cur = 0;
+		setrlimit (RLIMIT_CORE, &limit);
+#endif
+		close (pfd[0]);
+		if (pfd[1] != STDOUT_FILENO) {
+			dup2 (pfd[1], STDOUT_FILENO);
+			close (pfd[1]);
+		}
+		close (pfderr[0]);
+		if (pfderr[1] != STDERR_FILENO) {
+			dup2 (pfderr[1], STDERR_FILENO);
+			close (pfderr[1]);
+		}
+
+		/* close all descriptors in _cmd_pids[]
+		 * This is executed in a separate address space (pure child),
+		 * so we don't have to worry about async safety */
+		long maxfd = mp_open_max();
+		for (i = 0; i < maxfd; i++)
+			if (_cmd_pids[i] > 0)
+				close (i);
+
+		execve (argv[0], argv, environ);
+		_exit (STATE_UNKNOWN);
+	}
+
+	/* parent picks up execution here */
+	/* close children descriptors in our address space */
+	close (pfd[1]);
+	close (pfderr[1]);
+
+	/* tag our file's entry in the pid-list and return it */
+	_cmd_pids[pfd[0]] = pid;
+
+	return pfd[0];
+}
+
+static int
+_cmd_close (int fd)
+{
+	int status;
+	pid_t pid;
+
+	/* make sure the provided fd was opened */
+	long maxfd = mp_open_max();
+	if (fd < 0 || fd > maxfd || !_cmd_pids || (pid = _cmd_pids[fd]) == 0)
+		return -1;
+
+	_cmd_pids[fd] = 0;
+	if (close (fd) == -1)
+		return -1;
+
+	/* EINTR is ok (sort of), everything else is bad */
+	while (waitpid (pid, &status, 0) < 0)
+		if (errno != EINTR)
+			return -1;
+
+	/* return child's termination status */
+	return (WIFEXITED (status)) ? WEXITSTATUS (status) : -1;
+}
+
+
+static int
+_cmd_fetch_output (int fd, output * op, int flags)
+{
+	size_t len = 0, i = 0, lineno = 0;
+	size_t rsf = 6, ary_size = 0;	/* rsf = right shift factor, dec'ed uncond once */
+	char *buf = NULL;
+	int ret;
+	char tmpbuf[4096];
+
+	op->buf = NULL;
+	op->buflen = 0;
+	while ((ret = read (fd, tmpbuf, sizeof (tmpbuf))) > 0) {
+		len = (size_t) ret;
+		op->buf = realloc (op->buf, op->buflen + len + 1);
+		memcpy (op->buf + op->buflen, tmpbuf, len);
+		op->buflen += len;
+		i++;
+	}
+
+	if (ret < 0) {
+		printf ("read() returned %d: %s\n", ret, strerror (errno));
+		return ret;
+	}
+
+	/* some plugins may want to keep output unbroken, and some commands
+	 * will yield no output, so return here for those */
+	if (flags & CMD_NO_ARRAYS || !op->buf || !op->buflen)
+		return op->buflen;
+
+	/* and some may want both */
+	if (flags & CMD_NO_ASSOC) {
+		buf = malloc (op->buflen);
+		memcpy (buf, op->buf, op->buflen);
+	}
+	else
+		buf = op->buf;
+
+	op->line = NULL;
+	op->lens = NULL;
+	i = 0;
+	while (i < op->buflen) {
+		/* make sure we have enough memory */
+		if (lineno >= ary_size) {
+			/* ary_size must never be zero */
+			do {
+				ary_size = op->buflen >> --rsf;
+			} while (!ary_size);
+
+			op->line = realloc (op->line, ary_size * sizeof (char *));
+			op->lens = realloc (op->lens, ary_size * sizeof (size_t));
+		}
+
+		/* set the pointer to the string */
+		op->line[lineno] = &buf[i];
+
+		/* hop to next newline or end of buffer */
+		while (buf[i] != '\n' && i < op->buflen)
+			i++;
+		buf[i] = '\0';
+
+		/* calculate the string length using pointer difference */
+		op->lens[lineno] = (size_t) & buf[i] - (size_t) op->line[lineno];
+
+		lineno++;
+		i++;
+	}
+
+	return lineno;
+}
+
+
+int
+cmd_run (const char *cmdstring, output * out, output * err, int flags)
+{
+	int i = 0, argc;
+	size_t cmdlen;
+	char **argv = NULL;
+	char *cmd = NULL;
+	char *str = NULL;
+
+	if (cmdstring == NULL)
+		return -1;
+
+	/* initialize the structs */
+	if (out)
+		memset (out, 0, sizeof (output));
+	if (err)
+		memset (err, 0, sizeof (output));
+
+	/* make copy of command string so strtok() doesn't silently modify it */
+	/* (the calling program may want to access it later) */
+	cmdlen = strlen (cmdstring);
+	if ((cmd = malloc (cmdlen + 1)) == NULL)
+		return -1;
+	memcpy (cmd, cmdstring, cmdlen);
+	cmd[cmdlen] = '\0';
+
+	/* This is not a shell, so we don't handle "???" */
+	if (strstr (cmdstring, "\"")) return -1;
+
+	/* allow single quotes, but only if non-whitesapce doesn't occur on both sides */
+	if (strstr (cmdstring, " ' ") || strstr (cmdstring, "'''"))
+		return -1;
+
+	/* each arg must be whitespace-separated, so args can be a maximum
+	 * of (len / 2) + 1. We add 1 extra to the mix for NULL termination */
+	argc = (cmdlen >> 1) + 2;
+	argv = calloc (sizeof (char *), argc);
+
+	if (argv == NULL) {
+		printf ("%s\n", _("Could not malloc argv array in popen()"));
+		return -1;
+	}
+
+	/* get command arguments (stupidly, but fairly quickly) */
+	while (cmd) {
+		str = cmd;
+		str += strspn (str, " \t\r\n");	/* trim any leading whitespace */
+
+		if (strstr (str, "'") == str) {	/* handle SIMPLE quoted strings */
+			str++;
+			if (!strstr (str, "'"))
+				return -1;							/* balanced? */
+			cmd = 1 + strstr (str, "'");
+			str[strcspn (str, "'")] = 0;
+		}
+		else {
+			if (strpbrk (str, " \t\r\n")) {
+				cmd = 1 + strpbrk (str, " \t\r\n");
+				str[strcspn (str, " \t\r\n")] = 0;
+			}
+			else {
+				cmd = NULL;
+			}
+		}
+
+		if (cmd && strlen (cmd) == strspn (cmd, " \t\r\n"))
+			cmd = NULL;
+
+		argv[i++] = str;
+	}
+
+	return cmd_run_array (argv, out, err, flags);
+}
+
+int
+cmd_run_array (char *const *argv, output * out, output * err, int flags)
+{
+	int fd, pfd_out[2], pfd_err[2];
+
+	/* initialize the structs */
+	if (out)
+		memset (out, 0, sizeof (output));
+	if (err)
+		memset (err, 0, sizeof (output));
+
+	if ((fd = _cmd_open (argv, pfd_out, pfd_err)) == -1)
+		die (STATE_UNKNOWN, _("Could not open pipe: %s\n"), argv[0]);
+
+	if (out)
+		out->lines = _cmd_fetch_output (pfd_out[0], out, flags);
+	if (err)
+		err->lines = _cmd_fetch_output (pfd_err[0], err, flags);
+
+	return _cmd_close (fd);
+}
+
+int
+cmd_file_read ( char *filename, output *out, int flags)
+{
+	int fd;
+	if(out)
+		memset (out, 0, sizeof(output));
+
+	if ((fd = open(filename, O_RDONLY)) == -1) {
+		die( STATE_UNKNOWN, _("Error opening %s: %s"), filename, strerror(errno) );
+	}
+
+	if(out)
+		out->lines = _cmd_fetch_output (fd, out, flags);
+
+	if (close(fd) == -1)
+		die( STATE_UNKNOWN, _("Error closing %s: %s"), filename, strerror(errno) );
+
+	return 0;
+}
+
+void
+timeout_alarm_handler (int signo)
+{
+	size_t i;
+	if (signo == SIGALRM) {
+		printf (_("%s - Plugin timed out after %d seconds\n"),
+						state_text(timeout_state), timeout_interval);
+
+		long maxfd = mp_open_max();
+		if(_cmd_pids) for(i = 0; i < maxfd; i++) {
+			if(_cmd_pids[i] != 0) kill(_cmd_pids[i], SIGKILL);
+		}
+
+		exit (timeout_state);
+	}
+}