/* libguestfs - the guestfsd daemon
- * Copyright (C) 2009 Red Hat Inc.
+ * Copyright (C) 2009-2010 Red Hat Inc.
*
* 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
#include <sys/wait.h>
#include <arpa/inet.h>
#include <netinet/in.h>
+#include <errno.h>
#ifdef HAVE_PRINTF_H
# include <printf.h>
return 0;
}
-int
+size_t
count_strings (char *const *argv)
{
- int argc;
+ size_t argc;
for (argc = 0; argv[argc] != NULL; ++argc)
;
return argc;
}
+/* http://graphics.stanford.edu/~seander/bithacks.html#DetermineIfPowerOf2 */
+int
+is_power_of_2 (unsigned long v)
+{
+ return v && ((v & (v - 1)) == 0);
+}
+
static int
compare (const void *vp1, const void *vp2)
{
* error messages in the *stderror buffer. If using this flag,
* you should pass stdoutput as NULL because nothing could ever be
* captured in that buffer.
+ *
+ * COMMAND_FLAG_CHROOT_COPY_FILE_TO_STDIN: For running external
+ * commands on chrooted files correctly (see RHBZ#579608) specifying
+ * this flag causes another process to be forked which chroots into
+ * sysroot and just copies the input file to stdin of the specified
+ * command. The file descriptor is ORed with the flags, and that file
+ * descriptor is always closed by this function. See hexdump.c for an
+ * example of usage.
*/
int
commandrvf (char **stdoutput, char **stderror, int flags,
{
int so_size = 0, se_size = 0;
int so_fd[2], se_fd[2];
- pid_t pid;
+ int flag_copy_stdin = flags & COMMAND_FLAG_CHROOT_COPY_FILE_TO_STDIN;
+ int stdin_fd[2] = { -1, -1 };
+ pid_t pid, stdin_pid = -1;
int r, quit, i;
fd_set rset, rset2;
char buf[256];
printf ("\n");
}
+ /* Note: abort is used in a few places along the error paths early
+ * in this function. This is because (a) cleaning up correctly is
+ * very complex at these places and (b) abort is used when a
+ * resource problems is indicated which would be due to much more
+ * serious issues - eg. memory or file descriptor leaks. We
+ * wouldn't expect fork(2) or pipe(2) to fail in normal
+ * circumstances.
+ */
+
if (pipe (so_fd) == -1 || pipe (se_fd) == -1) {
- perror ("pipe");
- return -1;
+ error (0, errno, "pipe");
+ abort ();
+ }
+
+ if (flag_copy_stdin) {
+ if (pipe (stdin_fd) == -1) {
+ error (0, errno, "pipe");
+ abort ();
+ }
}
pid = fork ();
if (pid == -1) {
- perror ("fork");
- close (so_fd[0]);
- close (so_fd[1]);
- close (se_fd[0]);
- close (se_fd[1]);
- return -1;
+ error (0, errno, "fork");
+ abort ();
}
- if (pid == 0) { /* Child process. */
+ if (pid == 0) { /* Child process running the command. */
close (0);
- open ("/dev/null", O_RDONLY); /* Set stdin to /dev/null (ignore failure) */
+ if (flag_copy_stdin) {
+ dup2 (stdin_fd[0], 0);
+ close (stdin_fd[0]);
+ close (stdin_fd[1]);
+ } else {
+ /* Set stdin to /dev/null (ignore failure) */
+ open ("/dev/null", O_RDONLY);
+ }
close (so_fd[0]);
close (se_fd[0]);
if (!(flags & COMMAND_FLAG_FOLD_STDOUT_ON_STDERR))
execvp (argv[0], (void *) argv);
perror (argv[0]);
- _exit (1);
+ _exit (EXIT_FAILURE);
+ }
+
+ if (flag_copy_stdin) {
+ int fd = flags & COMMAND_FLAG_FD_MASK;
+
+ stdin_pid = fork ();
+ if (stdin_pid == -1) {
+ error (0, errno, "fork");
+ abort ();
+ }
+
+ if (stdin_pid == 0) { /* Child process copying stdin. */
+ close (so_fd[0]);
+ close (so_fd[1]);
+ close (se_fd[0]);
+ close (se_fd[1]);
+
+ close (1);
+ dup2 (stdin_fd[1], 1);
+ close (stdin_fd[0]);
+ close (stdin_fd[1]);
+
+ if (chroot (sysroot) == -1) {
+ perror ("chroot");
+ _exit (EXIT_FAILURE);
+ }
+
+ ssize_t n;
+ char buffer[BUFSIZ];
+ while ((n = read (fd, buffer, sizeof buffer)) > 0) {
+ if (xwrite (1, buffer, n) == -1)
+ /* EPIPE error indicates the command process has exited
+ * early. If the command process fails that will be caught
+ * by the daemon, and if not, then it's not an error.
+ */
+ _exit (errno == EPIPE ? EXIT_SUCCESS : EXIT_FAILURE);
+ }
+
+ if (n == -1) {
+ perror ("read");
+ _exit (EXIT_FAILURE);
+ }
+
+ if (close (fd) == -1) {
+ perror ("close");
+ _exit (EXIT_FAILURE);
+ }
+
+ _exit (EXIT_SUCCESS);
+ }
+
+ close (fd);
+ close (stdin_fd[0]);
+ close (stdin_fd[1]);
}
/* Parent process. */
close (so_fd[0]);
close (se_fd[0]);
waitpid (pid, NULL, 0);
+ if (stdin_pid >= 0) waitpid (stdin_pid, NULL, 0);
return -1;
}
}
}
+ if (flag_copy_stdin) {
+ /* Check copy process didn't fail. */
+ if (waitpid (stdin_pid, &r, 0) != stdin_pid) {
+ perror ("waitpid");
+ kill (pid, 9);
+ waitpid (pid, NULL, 0);
+ return -1;
+ }
+
+ if (!WIFEXITED (r) || WEXITSTATUS (r) != 0) {
+ fprintf (stderr, "failed copying from input file, see earlier messages\n");
+ kill (pid, 9);
+ waitpid (pid, NULL, 0);
+ return -1;
+ }
+ }
+
/* Get the exit status of the command. */
if (waitpid (pid, &r, 0) != pid) {
perror ("waitpid");
git.annexia.org / libguestfs.git / blobdiff