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-rw-r--r--plugins/popen.c314
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;
+}
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