Initial revision

git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@2 f882894a-f735-0410-b71e-b25c423dba1c

1 files changed, 314 insertions, 0 deletions

diff --git a/plugins/popen.c b/plugins/popen.c
new file mode 100644
index 00000000..cde3c764
--- /dev/null
+++ b/plugins/popen.c
@@ -0,0 +1,314 @@
+/******************************************************************************
+ * popen.c
+ *
+ * A safe alternative to popen
+ * 
+ * Provides spopen and spclose
+
+FILE * spopen(const char *);
+int spclose(FILE *);
+
+ *
+ * Code taken with liitle modification from "Advanced Programming for the Unix
+ * Environment" by W. Richard Stevens
+ *
+ * This is considered safe in that no shell is spawned, and the environment and
+ * path passed to the exec'd program are esstially empty. (popen create a shell
+ * and passes the environment to it).
+ *
+ ******************************************************************************/
+
+#include <config.h>
+#include <common.h>
+
+/* extern so plugin has pid to kill exec'd process on timeouts */
+extern int timeout_interval;
+extern pid_t *childpid;
+extern int *child_stderr_array;
+extern FILE *child_process;
+
+FILE *spopen (const char *);
+int spclose (FILE *);
+RETSIGTYPE popen_timeout_alarm_handler (int);
+
+#include <stdarg.h>							/* ANSI C header file */
+#include <fcntl.h>
+
+#include <limits.h>
+#include <sys/resource.h>
+
+#ifdef HAVE_SYS_WAIT_H
+#include <sys/wait.h>
+#endif
+
+#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
+
+#define	min(a,b)	((a) < (b) ? (a) : (b))
+#define	max(a,b)	((a) > (b) ? (a) : (b))
+int open_max (void);						/* {Prog openmax} */
+void err_sys (const char *, ...);
+char *rtrim (char *, const char *);
+
+/*int *childerr = NULL;*//* ptr to array allocated at run-time */
+/*extern pid_t *childpid = NULL; *//* ptr to array allocated at run-time */
+static int maxfd;								/* from our open_max(), {Prog openmax} */
+
+FILE *
+spopen (const char *cmdstring)
+{
+	char *environ[] = { NULL };
+	char *cmd = NULL;
+	char **argv = NULL;
+	char *str;
+	int argc;
+
+	int i = 0, pfd[2], pfderr[2];
+	pid_t pid;
+
+#ifdef 	RLIMIT_CORE
+	/* do not leave core files */
+	struct rlimit limit;
+	getrlimit (RLIMIT_CORE, &limit);
+	limit.rlim_cur = 0;
+	setrlimit (RLIMIT_CORE, &limit);
+#endif
+
+	/* if no command was passed, return with no error */
+	if (cmdstring == NULL)
+		return (NULL);
+
+	/* make copy of command string so strtok() doesn't silently modify it */
+	/* (the calling program may want to access it later) */
+	cmd = malloc (strlen (cmdstring) + 1);
+	if (cmd == NULL)
+		return NULL;
+	strcpy (cmd, cmdstring);
+
+	/* This is not a shell, so we don't handle "???" */
+	if (strstr (cmdstring, "\""))
+		return NULL;
+
+	/* allow single quotes, but only if non-whitesapce doesn't occur on both sides */
+	if (strstr (cmdstring, " ' ") || strstr (cmdstring, "'''"))
+		return NULL;
+
+	/* there cannot be more args than characters */
+	argc = strlen (cmdstring) + 1;	/* add 1 for NULL termination */
+	argv = malloc (sizeof(char*)*argc);
+	if (argv == NULL) {
+		printf ("Could not malloc argv array in popen()\n");
+		return NULL;
+	}
+
+	/* loop to get arguments to command */
+	while (cmd) {
+		str = cmd;
+		str += strspn (str, " \t\r\n");	/* trim any leading whitespace */
+
+		if (i >= argc - 2) {
+			printf ("You've got a big problem buddy! You need more args!!!\n");
+			return (NULL);
+		}
+
+		if (strstr (str, "'") == str) {	/* handle SIMPLE quoted strings */
+			str++;
+			if (!strstr (str, "'"))
+				return NULL;						/* 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;
+
+	}
+	argv[i] = NULL;
+
+	if (childpid == NULL) {				/* first time through */
+		maxfd = open_max ();				/* allocate zeroed out array for child pids */
+		if ((childpid = calloc (maxfd, sizeof (pid_t))) == NULL)
+			return (NULL);
+	}
+
+	if (child_stderr_array == NULL) {	/* first time through */
+		maxfd = open_max ();				/* allocate zeroed out array for child pids */
+		if ((child_stderr_array = calloc (maxfd, sizeof (int))) == NULL)
+			return (NULL);
+	}
+
+	if (pipe (pfd) < 0)
+		return (NULL);							/* errno set by pipe() */
+
+	if (pipe (pfderr) < 0)
+		return (NULL);							/* errno set by pipe() */
+
+	if ((pid = fork ()) < 0)
+		return (NULL);							/* errno set by fork() */
+	else if (pid == 0) {					/* child */
+		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 childpid[] */
+		for (i = 0; i < maxfd; i++)
+			if (childpid[i] > 0)
+				close (i);
+
+		execve (argv[0], argv, environ);
+		_exit (0);
+	}
+
+	close (pfd[1]);								/* parent */
+	if ((child_process = fdopen (pfd[0], "r")) == NULL)
+		return (NULL);
+	close (pfderr[1]);
+
+	childpid[fileno (child_process)] = pid;	/* remember child pid for this fd */
+	child_stderr_array[fileno (child_process)] = pfderr[0];	/* remember STDERR */
+	return (child_process);
+}
+
+int
+spclose (FILE * fp)
+{
+	int fd, stat;
+	pid_t pid;
+
+	if (childpid == NULL)
+		return (-1);								/* popen() has never been called */
+
+	fd = fileno (fp);
+	if ((pid = childpid[fd]) == 0)
+		return (-1);								/* fp wasn't opened by popen() */
+
+	childpid[fd] = 0;
+	if (fclose (fp) == EOF)
+		return (-1);
+
+	while (waitpid (pid, &stat, 0) < 0)
+		if (errno != EINTR)
+			return (-1);							/* error other than EINTR from waitpid() */
+
+	if (WIFEXITED (stat))
+		return (WEXITSTATUS (stat));	/* return child's termination status */
+
+	return (STATE_UNKNOWN);
+}
+
+#ifdef	OPEN_MAX
+static int openmax = OPEN_MAX;
+#else
+static int openmax = 0;
+#endif
+
+#define	OPEN_MAX_GUESS	256			/* if OPEN_MAX is indeterminate */
+				/* no guarantee this is adequate */
+
+void
+popen_timeout_alarm_handler (int signo)
+{
+	if (signo == SIGALRM) {
+		kill (childpid[fileno (child_process)], SIGKILL);
+		printf ("CRITICAL - Plugin timed out after %d seconds\n",
+						timeout_interval);
+		exit (STATE_CRITICAL);
+	}
+}
+
+int
+open_max (void)
+{
+	if (openmax == 0) {						/* first time through */
+		errno = 0;
+		if ((openmax = sysconf (_SC_OPEN_MAX)) < 0) {
+			if (errno == 0)
+				openmax = OPEN_MAX_GUESS;	/* it's indeterminate */
+			else
+				err_sys ("sysconf error for _SC_OPEN_MAX");
+		}
+	}
+	return (openmax);
+}
+
+
+static void err_doit (int, const char *, va_list);
+
+char *pname = NULL;							/* caller can set this from argv[0] */
+
+/* Fatal error related to a system call.
+ * Print a message and terminate. */
+
+void
+err_sys (const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start (ap, fmt);
+	err_doit (1, fmt, ap);
+	va_end (ap);
+	exit (1);
+}
+
+/* Print a message and return to caller.
+ * Caller specifies "errnoflag". */
+
+#define MAXLINE 2048
+static void
+err_doit (int errnoflag, const char *fmt, va_list ap)
+{
+	int errno_save;
+	char buf[MAXLINE];
+
+	errno_save = errno;						/* value caller might want printed */
+	vsprintf (buf, fmt, ap);
+	if (errnoflag)
+		sprintf (buf + strlen (buf), ": %s", strerror (errno_save));
+	strcat (buf, "\n");
+	fflush (stdout);							/* in case stdout and stderr are the same */
+	fputs (buf, stderr);
+	fflush (NULL);								/* flushes all stdio output streams */
+	return;
+}
+
+char *
+rtrim (char *str, const char *tok)
+{
+	int i = 0;
+
+	while (str != NULL) {
+		if (*(str + i) == *tok) {
+			sprintf (str + i, "%s", "\0");
+			return str;
+		}
+		i++;
+	}
+	return str;
+}