+/* libguestfs
+ * Copyright (C) 2010 Red Hat Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <inttypes.h>
+#include <unistd.h>
+#include <string.h>
+#include <sys/stat.h>
+
+#include <pcre.h>
+#include <magic.h>
+
+#include "ignore-value.h"
+
+#include "guestfs.h"
+#include "guestfs-internal.h"
+#include "guestfs-internal-actions.h"
+#include "guestfs_protocol.h"
+
+/* Compile all the regular expressions once when the shared library is
+ * loaded. PCRE is thread safe so we're supposedly OK here if
+ * multiple threads call into the libguestfs API functions below
+ * simultaneously.
+ */
+static pcre *re_file_elf;
+static pcre *re_file_win64;
+static pcre *re_elf_ppc64;
+
+static void compile_regexps (void) __attribute__((constructor));
+static void
+compile_regexps (void)
+{
+ const char *err;
+ int offset;
+
+#define COMPILE(re,pattern,options) \
+ do { \
+ re = pcre_compile ((pattern), (options), &err, &offset, NULL); \
+ if (re == NULL) { \
+ ignore_value (write (2, err, strlen (err))); \
+ abort (); \
+ } \
+ } while (0)
+
+ COMPILE (re_file_elf,
+ "ELF.*(?:executable|shared object|relocatable), (.+?),", 0);
+ COMPILE (re_elf_ppc64, "64.*PowerPC", 0);
+}
+
+/* Match a regular expression which contains no captures. Returns
+ * true if it matches or false if it doesn't.
+ */
+static int
+match (guestfs_h *g, const char *str, const pcre *re)
+{
+ size_t len = strlen (str);
+ int vec[30], r;
+
+ r = pcre_exec (re, NULL, str, len, 0, 0, vec, sizeof vec / sizeof vec[0]);
+ if (r == PCRE_ERROR_NOMATCH)
+ return 0;
+ if (r != 1) {
+ /* Internal error -- should not happen. */
+ fprintf (stderr, "libguestfs: %s: %s: internal error: pcre_exec returned unexpected error code %d when matching against the string \"%s\"\n",
+ __FILE__, __func__, r, str);
+ return 0;
+ }
+
+ return 1;
+}
+
+/* Match a regular expression which contains exactly one capture. If
+ * the string matches, return the capture, otherwise return NULL. The
+ * caller must free the result.
+ */
+static char *
+match1 (guestfs_h *g, const char *str, const pcre *re)
+{
+ size_t len = strlen (str);
+ int vec[30], r;
+
+ r = pcre_exec (re, NULL, str, len, 0, 0, vec, sizeof vec / sizeof vec[0]);
+ if (r == PCRE_ERROR_NOMATCH)
+ return NULL;
+ if (r != 2) {
+ /* Internal error -- should not happen. */
+ fprintf (stderr, "libguestfs: %s: %s: internal error: pcre_exec returned unexpected error code %d when matching against the string \"%s\"\n",
+ __FILE__, __func__, r, str);
+ return NULL;
+ }
+
+ return safe_strndup (g, &str[vec[2]], vec[3]-vec[2]);
+}
+
+/* Convert output from 'file' command on ELF files to the canonical
+ * architecture string. Caller must free the result.
+ */
+static char *
+canonical_elf_arch (guestfs_h *g, const char *elf_arch)
+{
+ const char *r;
+
+ if (strstr (elf_arch, "Intel 80386"))
+ r = "i386";
+ else if (strstr (elf_arch, "Intel 80486"))
+ r = "i486";
+ else if (strstr (elf_arch, "x86-64"))
+ r = "x86_64";
+ else if (strstr (elf_arch, "AMD x86-64"))
+ r = "x86_64";
+ else if (strstr (elf_arch, "SPARC32"))
+ r = "sparc";
+ else if (strstr (elf_arch, "SPARC V9"))
+ r = "sparc64";
+ else if (strstr (elf_arch, "IA-64"))
+ r = "ia64";
+ else if (match (g, elf_arch, re_elf_ppc64))
+ r = "ppc64";
+ else if (strstr (elf_arch, "PowerPC"))
+ r = "ppc";
+ else
+ r = elf_arch;
+
+ char *ret = safe_strdup (g, r);
+ return ret;
+}
+
+static int
+is_regular_file (const char *filename)
+{
+ struct stat statbuf;
+
+ return lstat (filename, &statbuf) == 0 && S_ISREG (statbuf.st_mode);
+}
+
+/* Download and uncompress the cpio file to find binaries within.
+ * Notes:
+ * (1) Two lists must be identical.
+ * (2) Implicit limit of 31 bytes for length of each element (see code
+ * below).
+ */
+#define INITRD_BINARIES1 "bin/ls bin/rm bin/modprobe sbin/modprobe bin/sh bin/bash bin/dash bin/nash"
+#define INITRD_BINARIES2 {"bin/ls", "bin/rm", "bin/modprobe", "sbin/modprobe", "bin/sh", "bin/bash", "bin/dash", "bin/nash"}
+
+static char *
+cpio_arch (guestfs_h *g, const char *file, const char *path)
+{
+ char *ret = NULL;
+
+ const char *method;
+ if (strstr (file, "gzip"))
+ method = "zcat";
+ else if (strstr (file, "bzip2"))
+ method = "bzcat";
+ else
+ method = "cat";
+
+ char dir[] = "/tmp/initrd.XXXXXX";
+#define dir_len (sizeof dir)
+ if (mkdtemp (dir) == NULL) {
+ perrorf (g, "mkdtemp");
+ goto out;
+ }
+
+ char dir_initrd[dir_len + 16];
+ snprintf (dir_initrd, dir_len + 16, "%s/initrd", dir);
+ if (guestfs_download (g, path, dir_initrd) == -1)
+ goto out;
+
+ char cmd[dir_len + 256];
+ snprintf (cmd, dir_len + 256,
+ "cd %s && %s initrd | cpio --quiet -id " INITRD_BINARIES1,
+ dir, method);
+ int r = system (cmd);
+ if (r == -1 || WEXITSTATUS (r) != 0) {
+ perrorf (g, "cpio command failed");
+ goto out;
+ }
+
+ char bin[dir_len + 32];
+ const char *bins[] = INITRD_BINARIES2;
+ size_t i;
+ for (i = 0; i < sizeof bins / sizeof bins[0]; ++i) {
+ snprintf (bin, dir_len + 32, "%s/%s", dir, bins[i]);
+
+ if (is_regular_file (bin)) {
+ int flags = g->verbose ? MAGIC_DEBUG : 0;
+ flags |= MAGIC_ERROR | MAGIC_RAW;
+
+ magic_t m = magic_open (flags);
+ if (m == NULL) {
+ perrorf (g, "magic_open");
+ goto out;
+ }
+
+ if (magic_load (m, NULL) == -1) {
+ perrorf (g, "magic_load: default magic database file");
+ magic_close (m);
+ goto out;
+ }
+
+ const char *line = magic_file (m, bin);
+ if (line == NULL) {
+ perrorf (g, "magic_file: %s", bin);
+ magic_close (m);
+ goto out;
+ }
+
+ char *elf_arch;
+ if ((elf_arch = match1 (g, line, re_file_elf)) != NULL) {
+ ret = canonical_elf_arch (g, elf_arch);
+ free (elf_arch);
+ magic_close (m);
+ goto out;
+ }
+ magic_close (m);
+ }
+ }
+ error (g, "file_architecture: could not determine architecture of cpio archive");
+
+ out:
+ /* Free up the temporary directory. Note the directory name cannot
+ * contain shell meta-characters because of the way it was
+ * constructed above.
+ */
+ snprintf (cmd, dir_len + 256, "rm -rf %s", dir);
+ ignore_value (system (cmd));
+
+ return ret;
+#undef dir_len
+}
+
+char *
+guestfs__file_architecture (guestfs_h *g, const char *path)
+{
+ char *file = NULL;
+ char *elf_arch = NULL;
+ char *ret = NULL;
+
+ /* Get the output of the "file" command. Note that because this
+ * runs in the daemon, LANG=C so it's in English.
+ */
+ file = guestfs_file (g, path);
+ if (file == NULL)
+ return NULL;
+
+ if ((elf_arch = match1 (g, file, re_file_elf)) != NULL)
+ ret = canonical_elf_arch (g, elf_arch);
+ else if (strstr (file, "PE32 executable"))
+ ret = safe_strdup (g, "i386");
+ else if (strstr (file, "PE32+ executable"))
+ ret = safe_strdup (g, "x86_64");
+ else if (strstr (file, "cpio archive"))
+ ret = cpio_arch (g, file, path);
+ else
+ error (g, "file_architecture: unknown architecture: %s", path);
+
+ free (file);
+ free (elf_arch);
+ return ret; /* caller frees */
+}
git.annexia.org / libguestfs.git / commitdiff