--- /dev/null
+/* libguestfs-supermin-helper reimplementation in C.
+ * 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
+ * the Free Software Foundation; either version 2 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, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+/* This script builds the supermin appliance on the fly each
+ * time the appliance runs.
+ *
+ * *NOTE*: This program is designed to be very short-lived, and so we
+ * don't normally bother to free up any memory that we allocate.
+ * That's not completely true - we free up stuff if it's obvious and
+ * easy to free up, and ignore the rest.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <string.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <limits.h>
+#include <fnmatch.h>
+#include <dirent.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+#include <assert.h>
+
+#include "error.h"
+#include "filevercmp.h"
+#include "fts_.h"
+#include "full-write.h"
+#include "hash.h"
+#include "hash-pjw.h"
+#include "xalloc.h"
+#include "xvasprintf.h"
+
+/* Directory containing candidate kernels. We could make this
+ * configurable at some point.
+ */
+#define KERNELDIR "/boot"
+#define MODULESDIR "/lib/modules"
+
+/* Buffer size used in copy operations throughout. Large for
+ * greatest efficiency.
+ */
+#define BUFFER_SIZE 65536
+
+static struct timeval start_t;
+static int verbose = 0;
+
+static void print_timestamped_message (const char *fs, ...);
+static const char *create_kernel (const char *hostcpu, const char *kernel);
+static void create_appliance (const char *sourcedir, const char *hostcpu, const char *repo, const char *modpath, const char *initrd);
+
+enum { HELP_OPTION = CHAR_MAX + 1 };
+
+static const char *options = "vV";
+static const struct option long_options[] = {
+ { "help", 0, 0, HELP_OPTION },
+ { "verbose", 0, 0, 'v' },
+ { "version", 0, 0, 'V' },
+ { 0, 0, 0, 0 }
+};
+
+static void
+usage (const char *progname)
+{
+ printf ("%s: build the supermin appliance on the fly\n"
+ "\n"
+ "Usage:\n"
+ " %s [-options] sourcedir host_cpu repo kernel initrd\n"
+ " %s --help\n"
+ " %s --version\n"
+ "\n"
+ "This script is used by libguestfs to build the supermin appliance\n"
+ "(kernel and initrd output files). You should NOT need to run this\n"
+ "program directly except if you are debugging tricky supermin\n"
+ "appliance problems.\n"
+ "\n"
+ "NB: The kernel and initrd parameters are OUTPUT parameters. If\n"
+ "those files exist, they are overwritten by the output.\n"
+ "\n"
+ "Options:\n"
+ " --help\n"
+ " Display this help text and exit.\n"
+ " --verbose | -v\n"
+ " Enable verbose messages (give multiple times for more verbosity).\n"
+ " --version | -V\n"
+ " Display version number and exit.\n"
+ "\n"
+ "Typical usage when debugging supermin appliance problems:\n"
+ " %s -v /usr/lib*/guestfs x86_64 fedora-12 /tmp/kernel /tmp/initrd\n"
+ "Note: This will OVERWRITE any existing files called /tmp/kernel\n"
+ "and /tmp/initrd.\n",
+ progname, progname, progname, progname, progname);
+}
+
+int
+main (int argc, char *argv[])
+{
+ /* First thing: start the clock. */
+ gettimeofday (&start_t, NULL);
+
+ /* Command line arguments. */
+ for (;;) {
+ int c = getopt_long (argc, argv, options, long_options, NULL);
+ if (c == -1) break;
+
+ switch (c) {
+ case HELP_OPTION:
+ usage (argv[0]);
+ exit (EXIT_SUCCESS);
+
+ case 'v':
+ verbose++;
+ break;
+
+ case 'V':
+ printf (PACKAGE_NAME " " PACKAGE_VERSION "\n");
+ exit (EXIT_SUCCESS);
+
+ default:
+ usage (argv[0]);
+ exit (EXIT_FAILURE);
+ }
+ }
+
+ if (argc - optind != 5) {
+ usage (argv[0]);
+ exit (EXIT_FAILURE);
+ }
+
+ const char *sourcedir = argv[optind];
+
+ /* Host CPU and repo constants passed from the library (see:
+ * https://bugzilla.redhat.com/show_bug.cgi?id=558593).
+ */
+ const char *hostcpu = argv[optind+1];
+ const char *repo = argv[optind+2];
+
+ /* Output files. */
+ const char *kernel = argv[optind+3];
+ const char *initrd = argv[optind+4];
+
+ if (verbose)
+ print_timestamped_message ("sourcedir = %s, "
+ "host_cpu = %s, "
+ "repo = %s, "
+ "kernel = %s, "
+ "initrd = %s",
+ sourcedir, hostcpu, repo, kernel, initrd);
+
+ /* Remove the output files if they exist. */
+ unlink (kernel);
+ unlink (initrd);
+
+ /* Create kernel output file. */
+ const char *modpath;
+ modpath = create_kernel (hostcpu, kernel);
+
+ if (verbose)
+ print_timestamped_message ("finished creating kernel");
+
+ /* Create the appliance. */
+ create_appliance (sourcedir, hostcpu, repo, modpath, initrd);
+
+ if (verbose)
+ print_timestamped_message ("finished creating appliance");
+
+ exit (EXIT_SUCCESS);
+}
+
+/* Compute Y - X and return the result in milliseconds.
+ * Approximately the same as this code:
+ * http://www.mpp.mpg.de/~huber/util/timevaldiff.c
+ */
+static int64_t
+timeval_diff (const struct timeval *x, const struct timeval *y)
+{
+ int64_t msec;
+
+ msec = (y->tv_sec - x->tv_sec) * 1000;
+ msec += (y->tv_usec - x->tv_usec) / 1000;
+ return msec;
+}
+
+static void
+print_timestamped_message (const char *fs, ...)
+{
+ struct timeval tv;
+ gettimeofday (&tv, NULL);
+
+ va_list args;
+ char *msg;
+ int err;
+
+ va_start (args, fs);
+ err = vasprintf (&msg, fs, args);
+ va_end (args);
+
+ if (err < 0) return;
+
+ fprintf (stderr, "supermin helper [%05" PRIi64 "ms] %s\n",
+ timeval_diff (&start_t, &tv), msg);
+
+ free (msg);
+}
+
+static char **read_dir (const char *dir);
+static char **filter_fnmatch (char **strings, const char *patt, int flags);
+static char **filter_notmatching_substring (char **strings, const char *sub);
+static void sort (char **strings, int (*compare) (const void *, const void *));
+static int isdir (const char *path);
+
+static int
+reverse_filevercmp (const void *p1, const void *p2)
+{
+ const char *s1 = * (char * const *) p1;
+ const char *s2 = * (char * const *) p2;
+
+ /* Note, arguments are reversed to achieve a reverse sort. */
+ return filevercmp (s2, s1);
+}
+
+/* Create the kernel. This chooses an appropriate kernel and makes a
+ * symlink to it.
+ *
+ * Look for the most recent kernel named vmlinuz-*.<arch>* which has a
+ * corresponding directory in /lib/modules/. If the architecture is
+ * x86, look for any x86 kernel.
+ *
+ * RHEL 5 didn't append the arch to the kernel name, so look for
+ * kernels without arch second.
+ *
+ * If no suitable kernel can be found, exit with an error.
+ *
+ * This function returns the module path (ie. /lib/modules/<version>).
+ */
+static const char *
+create_kernel (const char *hostcpu, const char *kernel)
+{
+ char **all_files = read_dir (KERNELDIR);
+
+ /* In original: ls -1dvr /boot/vmlinuz-*.$arch* 2>/dev/null | grep -v xen */
+ const char *patt;
+ if (hostcpu[0] == 'i' && hostcpu[2] == '8' && hostcpu[3] == '6' &&
+ hostcpu[4] == '\0')
+ patt = "vmlinuz-*.i?86*";
+ else
+ patt = xasprintf ("vmlinuz-*.%s*", hostcpu);
+
+ char **candidates;
+ candidates = filter_fnmatch (all_files, patt, FNM_NOESCAPE);
+ candidates = filter_notmatching_substring (candidates, "xen");
+
+ if (candidates[0] == NULL) {
+ /* In original: ls -1dvr /boot/vmlinuz-* 2>/dev/null | grep -v xen */
+ patt = "vmlinuz-*";
+ candidates = filter_fnmatch (all_files, patt, FNM_NOESCAPE);
+ candidates = filter_notmatching_substring (candidates, "xen");
+
+ if (candidates[0] == NULL)
+ goto no_kernels;
+ }
+
+ sort (candidates, reverse_filevercmp);
+
+ /* Choose the first candidate which has a corresponding /lib/modules
+ * directory.
+ */
+ int i;
+ for (i = 0; candidates[i] != NULL; ++i) {
+ if (verbose >= 2)
+ fprintf (stderr, "candidate kernel: " KERNELDIR "/%s\n", candidates[i]);
+
+ /* Ignore "vmlinuz-" at the beginning of the kernel name. */
+ const char *version = &candidates[i][8];
+
+ /* /lib/modules/<version> */
+ char *modpath = xasprintf (MODULESDIR "/%s", version);
+
+ if (verbose >= 2)
+ fprintf (stderr, "checking modpath %s is a directory\n", modpath);
+
+ if (isdir (modpath)) {
+ if (verbose >= 2)
+ fprintf (stderr, "picked %s because modpath %s exists\n",
+ candidates[i], modpath);
+
+ char *tmp = xasprintf (KERNELDIR "/%s", candidates[i]);
+
+ if (verbose >= 2)
+ fprintf (stderr, "creating symlink %s -> %s\n", kernel, tmp);
+
+ if (symlink (tmp, kernel) == -1)
+ error (EXIT_FAILURE, errno, "symlink kernel");
+
+ free (tmp);
+
+ return modpath;
+ }
+ }
+
+ /* Print more diagnostics here than the old script did. */
+ no_kernels:
+ fprintf (stderr,
+ "libguestfs-supermin-helper: failed to find a suitable kernel.\n"
+ "I looked for kernels in " KERNELDIR " and modules in " MODULESDIR
+ ".\n"
+ "If this is a Xen guest, and you only have Xen domU kernels\n"
+ "installed, try installing a fullvirt kernel (only for\n"
+ "libguestfs use, you shouldn't boot the Xen guest with it).\n");
+ exit (EXIT_FAILURE);
+}
+
+static void write_kernel_modules (const char *sourcedir, const char *modpath);
+static void write_hostfiles (const char *sourcedir, const char *hostcpu, const char *repo);
+static void write_to_fd (const void *buffer, size_t len);
+static void write_file_to_fd (const char *filename);
+static void write_file_len_to_fd (const char *filename, size_t len);
+static void write_padding (size_t len);
+static char **load_file (const char *filename);
+static void cpio_append_fts_entry (FTSENT *entry);
+static void cpio_append_stat (const char *filename, struct stat *);
+static void cpio_append (const char *filename);
+static void cpio_append_trailer (void);
+
+static int out_fd = -1;
+static off_t out_offset = 0;
+
+/* Create the appliance.
+ *
+ * The initrd consists of these components concatenated together:
+ *
+ * (1) The base skeleton appliance that we constructed at build time.
+ * name = initramfs.$repo.$host_cpu.supermin.img
+ * format = plain cpio
+ * (2) The modules from modpath which are on the module whitelist.
+ * format = plain cpio
+ * (3) The host files which match wildcards in *.supermin.hostfiles.
+ * format = plain cpio
+ *
+ * The original shell scripted used the external cpio program to
+ * create parts (2) and (3), but we have decided it's going to be
+ * faster if we just write out the data outselves. The reasons are
+ * that external cpio is slow (particularly when used with SELinux
+ * because it does 512 byte reads), and the format that we're writing
+ * is narrow and well understood, because we only care that the Linux
+ * kernel can read it.
+ */
+static void
+create_appliance (const char *sourcedir,
+ const char *hostcpu, const char *repo,
+ const char *modpath,
+ const char *initrd)
+{
+ out_fd = open (initrd, O_WRONLY | O_CREAT | O_TRUNC | O_NOCTTY, 0644);
+ if (out_fd == -1)
+ error (EXIT_FAILURE, errno, "open: %s", initrd);
+ out_offset = 0;
+
+ /* Copy the base skeleton appliance (1). */
+ char *tmp = xasprintf ("%s/initramfs.%s.%s.supermin.img",
+ sourcedir, repo, hostcpu);
+ write_file_to_fd (tmp);
+ free (tmp);
+
+ /* Kernel modules (2). */
+ write_kernel_modules (sourcedir, modpath);
+
+ /* Copy hostfiles (3). */
+ write_hostfiles (sourcedir, hostcpu, repo);
+
+ cpio_append_trailer ();
+
+ /* Finish off and close output file. */
+ if (close (out_fd) == -1)
+ error (EXIT_FAILURE, errno, "close: %s", initrd);
+}
+
+/* Copy kernel modules.
+ *
+ * Find every file under modpath.
+ *
+ * Exclude all *.ko files, *except* ones which match names in
+ * the whitelist (which may contain wildcards). Include all
+ * other files.
+ *
+ * Add chosen files to the output.
+ */
+static void
+write_kernel_modules (const char *sourcedir, const char *modpath)
+{
+ char *tmp = xasprintf ("%s/kmod.whitelist", sourcedir);
+ char **whitelist = load_file (tmp);
+ free (tmp);
+
+ char *paths[2] = { (char *) modpath, NULL };
+ FTS *fts = fts_open (paths, FTS_COMFOLLOW|FTS_PHYSICAL, NULL);
+ if (fts == NULL)
+ error (EXIT_FAILURE, errno, "write_kernel_modules: fts_open: %s", modpath);
+
+ for (;;) {
+ errno = 0;
+ FTSENT *entry = fts_read (fts);
+ if (entry == NULL && errno != 0)
+ error (EXIT_FAILURE, errno, "write_kernel_modules: fts_read: %s", modpath);
+ if (entry == NULL)
+ break;
+
+ /* Ignore directories being visited in post-order. */
+ if (entry->fts_info & FTS_DP)
+ continue;
+
+ /* Is it a *.ko file? */
+ if (entry->fts_namelen >= 3 &&
+ entry->fts_name[entry->fts_namelen-3] == '.' &&
+ entry->fts_name[entry->fts_namelen-2] == 'k' &&
+ entry->fts_name[entry->fts_namelen-1] == 'o') {
+ /* Is it a *.ko file which is on the whitelist? */
+ size_t j;
+ for (j = 0; whitelist[j] != NULL; ++j) {
+ int r;
+ r = fnmatch (whitelist[j], entry->fts_name, 0);
+ if (r == 0) {
+ /* It's on the whitelist, so include it. */
+ if (verbose >= 2)
+ fprintf (stderr, "including kernel module %s (matches whitelist entry %s)\n",
+ entry->fts_name, whitelist[j]);
+ cpio_append_fts_entry (entry);
+ break;
+ } else if (r != FNM_NOMATCH)
+ error (EXIT_FAILURE, 0, "internal error: fnmatch ('%s', '%s', %d) returned unexpected non-zero value %d\n",
+ whitelist[j], entry->fts_name, 0, r);
+ } /* for (j) */
+ } else
+ /* It's some other sort of file, or a directory, always include. */
+ cpio_append_fts_entry (entry);
+ }
+
+ if (fts_close (fts) == -1)
+ error (EXIT_FAILURE, errno, "write_kernel_modules: fts_close: %s", modpath);
+}
+
+/* Copy the host files.
+ *
+ * Read the list of entries in *.supermin.hostfiles (which may contain
+ * wildcards). Look them up in the filesystem, and add those files
+ * that exist. Ignore any files that don't exist or are not readable.
+ */
+static void
+write_hostfiles (const char *sourcedir, const char *hostcpu, const char *repo)
+{
+ char *tmp = xasprintf ("%s/initramfs.%s.%s.supermin.hostfiles",
+ sourcedir, repo, hostcpu);
+ char **hostfiles = load_file (tmp);
+ free (tmp);
+
+ /* Hostfiles list can contain "." before each path - ignore it.
+ * It also contains each directory name before we enter it. But
+ * we don't read that until we see a wildcard for that directory.
+ */
+ size_t i, j;
+ for (i = 0; hostfiles[i] != NULL; ++i) {
+ char *hostfile = hostfiles[i];
+ if (hostfile[0] == '.')
+ hostfile++;
+
+ struct stat statbuf;
+
+ /* Is it a wildcard? */
+ if (strchr (hostfile, '*') || strchr (hostfile, '?')) {
+ char *dirname = xstrdup (hostfile);
+ char *patt = strrchr (dirname, '/');
+ assert (patt);
+ *patt++ = '\0';
+
+ char **files = read_dir (dirname);
+ files = filter_fnmatch (files, patt, FNM_NOESCAPE);
+
+ /* Add matching files. */
+ for (j = 0; files[j] != NULL; ++j) {
+ tmp = xasprintf ("%s/%s", dirname, files[j]);
+
+ if (verbose >= 2)
+ fprintf (stderr, "including host file %s (matches %s)\n", tmp, patt);
+
+ cpio_append (tmp);
+
+ free (tmp);
+ }
+ }
+ /* Else does this file/directory/whatever exist? */
+ else if (lstat (hostfile, &statbuf) == 0) {
+ if (verbose >= 2)
+ fprintf (stderr, "including host file %s (directly referenced)\n",
+ hostfile);
+
+ cpio_append_stat (hostfile, &statbuf);
+ } /* Ignore files that don't exist. */
+ }
+}
+
+/*----------*/
+/* Helper functions. */
+
+static void
+add_string (char ***argv, size_t *n_used, size_t *n_alloc, const char *str)
+{
+ char **new_argv;
+ char *new_str;
+
+ if (*n_used >= *n_alloc)
+ *argv = x2nrealloc (*argv, n_alloc, sizeof (char *));
+
+ if (str)
+ new_str = xstrdup (str);
+ else
+ new_str = NULL;
+
+ (*argv)[*n_used] = new_str;
+
+ (*n_used)++;
+}
+
+static size_t
+count_strings (char *const *argv)
+{
+ size_t argc;
+
+ for (argc = 0; argv[argc] != NULL; ++argc)
+ ;
+ return argc;
+}
+
+struct dir_cache {
+ char *path;
+ char **files;
+};
+
+static size_t
+dir_cache_hash (void const *x, size_t table_size)
+{
+ struct dir_cache const *p = x;
+ return hash_pjw (p->path, table_size);
+}
+
+static bool
+dir_cache_compare (void const *x, void const *y)
+{
+ struct dir_cache const *p = x;
+ struct dir_cache const *q = y;
+ return strcmp (p->path, q->path) == 0;
+}
+
+/* Read a directory into a list of strings.
+ *
+ * Previously looked up directories are cached and returned quickly,
+ * saving some considerable amount of time compared to reading the
+ * directory over again. However this means you really must not
+ * alter the array of strings that are returned.
+ *
+ * Returns an empty list if the directory cannot be opened.
+ */
+static char **
+read_dir (const char *name)
+{
+ static Hash_table *ht = NULL;
+
+ if (!ht)
+ ht = hash_initialize (1024, NULL, dir_cache_hash, dir_cache_compare, NULL);
+
+ struct dir_cache key = { .path = (char *) name };
+ struct dir_cache *p = hash_lookup (ht, &key);
+ if (p)
+ return p->files;
+
+ char **files = NULL;
+ size_t n_used = 0, n_alloc = 0;
+
+ DIR *dir = opendir (name);
+ if (!dir) {
+ /* If it fails to open, that's OK, skip to the end. */
+ /*perror (name);*/
+ goto done;
+ }
+
+ for (;;) {
+ errno = 0;
+ struct dirent *d = readdir (dir);
+ if (d == NULL) {
+ if (errno != 0)
+ /* But if it fails here, after opening and potentially reading
+ * part of the directory, that's a proper failure - inform the
+ * user and exit.
+ */
+ error (EXIT_FAILURE, errno, "%s", name);
+ break;
+ }
+
+ add_string (&files, &n_used, &n_alloc, d->d_name);
+ }
+
+ if (closedir (dir) == -1)
+ error (EXIT_FAILURE, errno, "closedir: %s", name);
+
+ done:
+ /* NULL-terminate the array. */
+ add_string (&files, &n_used, &n_alloc, NULL);
+
+ /* Add it to the hash for next time. */
+ p = xmalloc (sizeof *p);
+ p->path = (char *) name;
+ p->files = files;
+ p = hash_insert (ht, p);
+ assert (p != NULL);
+
+ return files;
+}
+
+/* Filter a list of strings and return only those matching the wildcard. */
+static char **
+filter_fnmatch (char **strings, const char *patt, int flags)
+{
+ char **out = NULL;
+ size_t n_used = 0, n_alloc = 0;
+
+ int i, r;
+ for (i = 0; strings[i] != NULL; ++i) {
+ r = fnmatch (patt, strings[i], flags);
+ if (r == 0)
+ add_string (&out, &n_used, &n_alloc, strings[i]);
+ else if (r != FNM_NOMATCH)
+ error (EXIT_FAILURE, 0, "internal error: fnmatch ('%s', '%s', %d) returned unexpected non-zero value %d\n",
+ patt, strings[i], flags, r);
+ }
+
+ add_string (&out, &n_used, &n_alloc, NULL);
+ return out;
+}
+
+/* Filter a list of strings and return only those which DON'T contain sub. */
+static char **
+filter_notmatching_substring (char **strings, const char *sub)
+{
+ char **out = NULL;
+ size_t n_used = 0, n_alloc = 0;
+
+ int i;
+ for (i = 0; strings[i] != NULL; ++i) {
+ if (strstr (strings[i], sub) == NULL)
+ add_string (&out, &n_used, &n_alloc, strings[i]);
+ }
+
+ add_string (&out, &n_used, &n_alloc, NULL);
+ return out;
+}
+
+/* Sort a list of strings, in place, with the comparison function supplied. */
+static void
+sort (char **strings, int (*compare) (const void *, const void *))
+{
+ qsort (strings, count_strings (strings), sizeof (char *), compare);
+}
+
+/* Return true iff path exists and is a directory. This version
+ * follows symlinks.
+ */
+static int
+isdir (const char *path)
+{
+ struct stat statbuf;
+
+ if (stat (path, &statbuf) == -1)
+ return 0;
+
+ return S_ISDIR (statbuf.st_mode);
+}
+
+/* Copy contents of buffer to out_fd and keep out_offset correct. */
+static void
+write_to_fd (const void *buffer, size_t len)
+{
+ if (full_write (out_fd, buffer, len) != len)
+ error (EXIT_FAILURE, errno, "write");
+ out_offset += len;
+}
+
+/* Copy contents of file to out_fd. */
+static void
+write_file_to_fd (const char *filename)
+{
+ char buffer[BUFFER_SIZE];
+ int fd2;
+ ssize_t r;
+
+ if (verbose >= 2)
+ fprintf (stderr, "write_file_to_fd %s -> %d\n", filename, out_fd);
+
+ fd2 = open (filename, O_RDONLY);
+ if (fd2 == -1)
+ error (EXIT_FAILURE, errno, "open: %s", filename);
+ for (;;) {
+ r = read (fd2, buffer, sizeof buffer);
+ if (r == 0)
+ break;
+ if (r == -1) {
+ if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
+ continue;
+ error (EXIT_FAILURE, errno, "read: %s", filename);
+ }
+ write_to_fd (buffer, r);
+ }
+
+ if (close (fd2) == -1)
+ error (EXIT_FAILURE, errno, "close: %s", filename);
+}
+
+/* Copy file of given length to output, and fail if the file has
+ * changed size.
+ */
+static void
+write_file_len_to_fd (const char *filename, size_t len)
+{
+ char buffer[BUFFER_SIZE];
+ size_t count = 0;
+
+ if (verbose >= 2)
+ fprintf (stderr, "write_file_to_fd %s -> %d\n", filename, out_fd);
+
+ int fd2 = open (filename, O_RDONLY);
+ if (fd2 == -1)
+ error (EXIT_FAILURE, errno, "open: %s", filename);
+ for (;;) {
+ ssize_t r = read (fd2, buffer, sizeof buffer);
+ if (r == 0)
+ break;
+ if (r == -1) {
+ if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
+ continue;
+ error (EXIT_FAILURE, errno, "read: %s", filename);
+ }
+ write_to_fd (buffer, r);
+ count += r;
+ if (count > len)
+ error (EXIT_FAILURE, 0, "write_file_len_to_fd: %s: file has increased in size\n", filename);
+ }
+
+ if (close (fd2) == -1)
+ error (EXIT_FAILURE, errno, "close: %s", filename);
+
+ if (count != len)
+ error (EXIT_FAILURE, 0, "libguestfs-supermin-helper: write_file_len_to_fd: %s: file has changed size\n", filename);
+}
+
+/* Load in a file, returning a list of lines. */
+static char **
+load_file (const char *filename)
+{
+ char **lines = 0;
+ size_t n_used = 0, n_alloc = 0;
+
+ FILE *fp;
+ fp = fopen (filename, "r");
+ if (fp == NULL)
+ error (EXIT_FAILURE, errno, "fopen: %s", filename);
+
+ char line[4096];
+ while (fgets (line, sizeof line, fp)) {
+ size_t len = strlen (line);
+ if (len > 0 && line[len-1] == '\n')
+ line[len-1] = '\0';
+ add_string (&lines, &n_used, &n_alloc, line);
+ }
+
+ add_string (&lines, &n_used, &n_alloc, NULL);
+ return lines;
+}
+
+/* Append the file pointed to by FTSENT to the cpio output. */
+static void
+cpio_append_fts_entry (FTSENT *entry)
+{
+ if (entry->fts_info & FTS_NS || entry->fts_info & FTS_NSOK)
+ cpio_append (entry->fts_path);
+ else
+ cpio_append_stat (entry->fts_path, entry->fts_statp);
+}
+
+/* Append the file named 'filename' to the cpio output. */
+static void
+cpio_append (const char *filename)
+{
+ struct stat statbuf;
+
+ if (lstat (filename, &statbuf) == -1)
+ error (EXIT_FAILURE, errno, "lstat: %s", filename);
+ cpio_append_stat (filename, &statbuf);
+}
+
+/* Append the file to the cpio output. */
+#define PADDING(len) ((((len) + 3) & ~3) - (len))
+
+#define CPIO_HEADER_LEN (6 + 13*8)
+
+static void
+cpio_append_stat (const char *filename, struct stat *statbuf)
+{
+ const char *orig_filename = filename;
+
+ if (*filename == '/')
+ filename++;
+ if (*filename == '\0')
+ filename = ".";
+
+ if (verbose >= 2)
+ fprintf (stderr, "cpio_append_stat %s 0%o -> %d\n",
+ orig_filename, statbuf->st_mode, out_fd);
+
+ /* Regular files and symlinks are the only ones that have a "body"
+ * in this cpio entry.
+ */
+ int has_body = S_ISREG (statbuf->st_mode) || S_ISLNK (statbuf->st_mode);
+
+ size_t len = strlen (filename) + 1;
+
+ char header[CPIO_HEADER_LEN + 1];
+ snprintf (header, sizeof header,
+ "070701" /* magic */
+ "%08X" /* inode */
+ "%08X" /* mode */
+ "%08X" "%08X" /* uid, gid */
+ "%08X" /* nlink */
+ "%08X" /* mtime */
+ "%08X" /* file length */
+ "%08X" "%08X" /* device holding file major, minor */
+ "%08X" "%08X" /* for specials, device major, minor */
+ "%08X" /* name length (including \0 byte) */
+ "%08X", /* checksum (not used by the kernel) */
+ (unsigned) statbuf->st_ino, statbuf->st_mode,
+ statbuf->st_uid, statbuf->st_gid,
+ (unsigned) statbuf->st_nlink, (unsigned) statbuf->st_mtime,
+ has_body ? (unsigned) statbuf->st_size : 0,
+ major (statbuf->st_dev), minor (statbuf->st_dev),
+ major (statbuf->st_rdev), minor (statbuf->st_rdev),
+ (unsigned) len, 0);
+
+ /* Write the header. */
+ write_to_fd (header, CPIO_HEADER_LEN);
+
+ /* Follow with the filename, and pad it. */
+ write_to_fd (filename, len);
+ size_t padding_len = PADDING (CPIO_HEADER_LEN + len);
+ write_padding (padding_len);
+
+ /* Follow with the file or symlink content, and pad it. */
+ if (has_body) {
+ if (S_ISREG (statbuf->st_mode))
+ write_file_len_to_fd (orig_filename, statbuf->st_size);
+ else if (S_ISLNK (statbuf->st_mode)) {
+ char tmp[PATH_MAX];
+ if (readlink (orig_filename, tmp, sizeof tmp) == -1)
+ error (EXIT_FAILURE, errno, "readlink: %s", orig_filename);
+ write_to_fd (tmp, statbuf->st_size);
+ }
+
+ padding_len = PADDING (statbuf->st_size);
+ write_padding (padding_len);
+ }
+}
+
+/* CPIO voodoo. */
+static void
+cpio_append_trailer (void)
+{
+ struct stat statbuf;
+ memset (&statbuf, 0, sizeof statbuf);
+ statbuf.st_nlink = 1;
+ cpio_append_stat ("TRAILER!!!", &statbuf);
+
+ /* CPIO seems to pad up to the next block boundary, ie. up to
+ * the next 512 bytes.
+ */
+ write_padding (((out_offset + 511) & ~511) - out_offset);
+ assert ((out_offset & 511) == 0);
+}
+
+/* Write 'len' bytes of zeroes out. */
+static void
+write_padding (size_t len)
+{
+ static const char buffer[512] = { 0 };
+
+ while (len > 0) {
+ size_t n = len < sizeof buffer ? len : sizeof buffer;
+ write_to_fd (buffer, n);
+ len -= n;
+ }
+}
git.annexia.org / libguestfs.git / commitdiff