* 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"
+#include "helper.h"
-/* 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 (char **inputs, int nr_inputs, const char *whitelist, const char *modpath, const char *initrd);
+struct timeval start_t;
+int verbose = 0;
enum { HELP_OPTION = CHAR_MAX + 1 };
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 (char **strings, int (*)(const char *));
-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);
-}
-
-static char *
-get_modpath (const char *kernel_name)
-{
- /* Ignore "vmlinuz-" at the beginning of the kernel name. */
- const char *version = &kernel_name[8];
-
- /* /lib/modules/<version> */
- char *modpath = xasprintf (MODULESDIR "/%s", version);
- if (!modpath) {
- perror ("xasprintf");
- exit (EXIT_FAILURE);
- }
-
- return modpath;
-}
-
-/* kernel_name is "vmlinuz-*". Check if there is a corresponding
- * module path in /lib/modules.
- */
-static int
-has_modpath (const char *kernel_name)
-{
- char *modpath = get_modpath (kernel_name);
-
- if (verbose)
- fprintf (stderr, "checking modpath %s is a directory\n", modpath);
-
- int r = isdir (modpath);
-
- if (r) {
- if (verbose)
- fprintf (stderr, "picked %s because modpath %s exists\n",
- kernel_name, modpath);
- free (modpath);
- return 1;
- }
- else {
- free (modpath);
- return 0;
- }
-}
-
-/* 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");
- candidates = filter (candidates, has_modpath);
-
- 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");
- candidates = filter (candidates, has_modpath);
-
- if (candidates[0] == NULL)
- goto no_kernels;
- }
-
- sort (candidates, reverse_filevercmp);
-
- /* Choose the first candidate. */
- char *tmp = xasprintf (KERNELDIR "/%s", candidates[0]);
-
- if (verbose)
- fprintf (stderr, "creating symlink %s -> %s\n", kernel, tmp);
-
- if (symlink (tmp, kernel) == -1)
- error (EXIT_FAILURE, errno, "symlink kernel");
-
- free (tmp);
-
- return get_modpath (candidates[0]);
-
- /* Print more diagnostics here than the old script did. */
- no_kernels:
- fprintf (stderr,
- "febootstrap-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"
- "febootstrap use, you shouldn't boot the Xen guest with it).\n");
- exit (EXIT_FAILURE);
-}
-
-static void iterate_inputs (char **inputs, int nr_inputs);
-static void iterate_input_directory (const char *dirname, int dirfd);
-static void write_kernel_modules (const char *whitelist, const char *modpath);
-static void write_hostfiles (const char *hostfiles_file);
-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.
- * format = plain cpio
- * (2) The host files which match wildcards in *.supermin.hostfiles.
- * input format = plain text, output format = plain cpio
- * (3) The modules from modpath which are on the module whitelist.
- * output format = plain cpio
- *
- * The original shell script 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.
- *
- * This version contains some improvements over the C version written
- * for libguestfs, in that we can have multiple base images (or
- * hostfiles) or use a directory to store these files.
- */
-static void
-create_appliance (char **inputs, int nr_inputs,
- const char *whitelist,
- 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;
-
- iterate_inputs (inputs, nr_inputs);
-
- /* Kernel modules (3). */
- write_kernel_modules (whitelist, modpath);
-
- cpio_append_trailer ();
-
- /* Finish off and close output file. */
- if (close (out_fd) == -1)
- error (EXIT_FAILURE, errno, "close: %s", initrd);
-}
-
-/* Iterate over the inputs to find out what they are, visiting
- * directories if specified.
- */
-static void
-iterate_inputs (char **inputs, int nr_inputs)
-{
- int i;
- for (i = 0; i < nr_inputs; ++i) {
- if (verbose)
- print_timestamped_message ("visiting %s", inputs[i]);
-
- int fd = open (inputs[i], O_RDONLY);
- if (fd == -1)
- error (EXIT_FAILURE, errno, "open: %s", inputs[i]);
-
- struct stat statbuf;
- if (fstat (fd, &statbuf) == -1)
- error (EXIT_FAILURE, errno, "fstat: %s", inputs[i]);
-
- /* Directory? */
- if (S_ISDIR (statbuf.st_mode))
- iterate_input_directory (inputs[i], fd);
- else if (S_ISREG (statbuf.st_mode)) {
- /* Is it a cpio file? */
- char buf[6];
- if (read (fd, buf, 6) == 6 && memcmp (buf, "070701", 6) == 0)
- /* Yes, a cpio file. This is a skeleton appliance, case (1). */
- write_file_to_fd (inputs[i]);
- else
- /* No, must be hostfiles, case (2). */
- write_hostfiles (inputs[i]);
- }
- else
- error (EXIT_FAILURE, 0, "%s: input is not a regular file or directory",
- inputs[i]);
-
- close (fd);
- }
-}
-
-static void
-iterate_input_directory (const char *dirname, int dirfd)
-{
- char path[PATH_MAX];
- strcpy (path, dirname);
- size_t len = strlen (dirname);
- path[len++] = '/';
-
- char *inputs[] = { path };
-
- DIR *dir = fdopendir (dirfd);
- if (dir == NULL)
- error (EXIT_FAILURE, errno, "fdopendir: %s", dirname);
-
- struct dirent *d;
- while ((errno = 0, d = readdir (dir)) != NULL) {
- if (d->d_name[0] == '.') /* ignore ., .. and any hidden files. */
- continue;
-
- strcpy (&path[len], d->d_name);
- iterate_inputs (inputs, 1);
- }
-
- if (errno != 0)
- error (EXIT_FAILURE, errno, "readdir: %s", dirname);
-
- if (closedir (dir) == -1)
- error (EXIT_FAILURE, errno, "closedir: %s", dirname);
-}
-
-/* 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.
- *
- * whitelist_file may be NULL, to include ALL kernel modules.
- */
-static void
-write_kernel_modules (const char *whitelist_file, const char *modpath)
-{
- char **whitelist = NULL;
- if (whitelist_file != NULL)
- whitelist = load_file (whitelist_file);
-
- 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') {
- if (whitelist) {
- /* 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 { /* whitelist == NULL, always include */
- if (verbose >= 2)
- fprintf (stderr, "including kernel module %s\n", entry->fts_name);
- cpio_append_fts_entry (entry);
- }
- } 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 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 *hostfiles_file)
-{
- char **hostfiles = load_file (hostfiles_file);
-
- /* 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) {
- char *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_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, returning only those where f(s) != 0. */
-static char **
-filter (char **strings, int (*f) (const char *))
-{
- char **out = NULL;
- size_t n_used = 0, n_alloc = 0;
-
- int i;
- for (i = 0; strings[i] != NULL; ++i) {
- if (f (strings[i]) != 0)
- add_string (&out, &n_used, &n_alloc, strings[i]);
- }
-
- add_string (&out, &n_used, &n_alloc, NULL);
- return out;
-}
-
-/* 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, "febootstrap-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 / febootstrap.git / blobdiff