1 files changed, 314 insertions, 0 deletions

diff --git a/plugins/popen.c b/plugins/popen.c
new file mode 100644
index 0000000..cde3c76
--- /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;
+}