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[Libguestfs] [PATCH 1/3] New API: file-architecture



-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
libguestfs lets you edit virtual machines.  Supports shell scripting,
bindings from many languages.  http://et.redhat.com/~rjones/libguestfs/
See what it can do: http://et.redhat.com/~rjones/libguestfs/recipes.html
>From fd8f045673a71f312fcc174bdf7baaca87a38b02 Mon Sep 17 00:00:00 2001
From: Richard Jones <rjones redhat com>
Date: Wed, 28 Jul 2010 15:38:57 +0100
Subject: [PATCH 1/3] New API: file-architecture

This change simply converts the existing Perl-only function
file_architecture into a core API call.  The core API call is
written in C and available in all languages and from guestfish.
---
 README                      |    2 +
 configure.ac                |    9 ++
 perl/lib/Sys/Guestfs/Lib.pm |   68 +-----------
 perl/t/510-lib-file-arch.t  |   70 -----------
 po/POTFILES.in              |    1 +
 src/Makefile.am             |    3 +-
 src/generator.ml            |  128 +++++++++++++++++++++
 src/inspect.c               |  266 +++++++++++++++++++++++++++++++++++++++++++
 8 files changed, 410 insertions(+), 137 deletions(-)
 delete mode 100644 perl/t/510-lib-file-arch.t
 create mode 100644 src/inspect.c

diff --git a/README b/README
index ea1da1f..e542073 100644
--- a/README
+++ b/README
@@ -48,6 +48,8 @@ Requirements
 
 - XDR, rpcgen (on Linux these are provided by glibc)
 
+- pcre (Perl Compatible Regular Expressions C library)
+
 - squashfs-tools (mksquashfs only)
 
 - genisoimage / mkisofs
diff --git a/configure.ac b/configure.ac
index a14dfd9..9cb2278 100644
--- a/configure.ac
+++ b/configure.ac
@@ -185,6 +185,15 @@ AC_ARG_ENABLE([appliance],
 AM_CONDITIONAL([ENABLE_APPLIANCE],[test "x$enable_appliance" = "xyes"])
 AC_MSG_RESULT([$enable_appliance])
 
+dnl Check for PCRE.
+AC_CHECK_LIB([pcre],[pcre_compile],
+        [AC_SUBST([LIBPCRE], ["-lpcre"])],
+        [AC_MSG_FAILURE(
+             [Perl Compatible Regular Expressions library (PCRE) is required])])
+AC_CHECK_HEADER([pcre.h],[],
+        [AC_MSG_FAILURE(
+             [Perl Compatible Regular Expressions library (PCRE) header file pcre.h is required])])
+
 dnl Check for rpcgen and XDR library.  rpcgen is optional.
 AC_CHECK_PROG([RPCGEN],[rpcgen],[rpcgen],[no])
 AM_CONDITIONAL([HAVE_RPCGEN],[test "x$RPCGEN" != "xno"])
diff --git a/perl/lib/Sys/Guestfs/Lib.pm b/perl/lib/Sys/Guestfs/Lib.pm
index bdc788e..22a0daf 100644
--- a/perl/lib/Sys/Guestfs/Lib.pm
+++ b/perl/lib/Sys/Guestfs/Lib.pm
@@ -347,72 +347,8 @@ sub resolve_windows_path
 
 =head2 file_architecture
 
- $arch = file_architecture ($g, $path)
-
-The C<file_architecture> function lets you get the architecture for a
-particular binary or library in the guest.  By "architecture" we mean
-what processor it is compiled for (eg. C<i586> or C<x86_64>).
-
-The function works on at least the following types of files:
-
-=over 4
-
-=item *
-
-many types of Un*x binary
-
-=item *
-
-many types of Un*x shared library
-
-=item *
-
-Windows Win32 and Win64 binaries
-
-=item *
-
-Windows Win32 and Win64 DLLs
-
-Win32 binaries and DLLs return C<i386>.
-
-Win64 binaries and DLLs return C<x86_64>.
-
-=item *
-
-Linux kernel modules
-
-=item *
-
-Linux new-style initrd images
-
-=item *
-
-some non-x86 Linux vmlinuz kernels
-
-=back
-
-What it can't do currently:
-
-=over 4
-
-=item *
-
-static libraries (libfoo.a)
-
-=item *
-
-Linux old-style initrd as compressed ext2 filesystem (RHEL 3)
-
-=item *
-
-x86 Linux vmlinuz kernels
-
-x86 vmlinuz images (bzImage format) consist of a mix of 16-, 32- and
-compressed code, and are horribly hard to unpack.  If you want to find
-the architecture of a kernel, use the architecture of the associated
-initrd or kernel module(s) instead.
-
-=back
+This code is deprecated.  L<Sys::Guestfs(3)> contains an equivalent
+C<file_architecture> call which you should use instead.
 
 =cut
 
diff --git a/perl/t/510-lib-file-arch.t b/perl/t/510-lib-file-arch.t
deleted file mode 100644
index dfe32bc..0000000
--- a/perl/t/510-lib-file-arch.t
+++ /dev/null
@@ -1,70 +0,0 @@
-# libguestfs Perl bindings -*- perl -*-
-# Copyright (C) 2009 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.
-
-use strict;
-use warnings;
-
-BEGIN {
-    use Test::More;
-    eval "use Locale::TextDomain";;
-    if (exists $INC{"Locale/TextDomain.pm"}) {
-        plan tests => 16;
-    } else {
-        plan skip_all => "no perl-libintl module";
-        exit 0;
-    }
-}
-
-use Sys::Guestfs;
-use Sys::Guestfs::Lib;
-
-my $h = Sys::Guestfs->new ();
-ok ($h);
-
-$h->add_drive_ro ("../images/test.iso");
-ok (1);
-
-$h->launch ();
-ok (1);
-
-$h->mount_ro ("/dev/sda", "/");
-ok (1);
-
-is (Sys::Guestfs::Lib::file_architecture ($h, "/bin-i586-dynamic"),
-    "i386");
-is (Sys::Guestfs::Lib::file_architecture ($h, "/bin-sparc-dynamic"),
-    "sparc");
-is (Sys::Guestfs::Lib::file_architecture ($h, "/bin-win32.exe"),
-    "i386");
-is (Sys::Guestfs::Lib::file_architecture ($h, "/bin-win64.exe"),
-    "x86_64");
-is (Sys::Guestfs::Lib::file_architecture ($h, "/bin-x86_64-dynamic"),
-    "x86_64");
-is (Sys::Guestfs::Lib::file_architecture ($h, "/lib-i586.so"),
-    "i386");
-is (Sys::Guestfs::Lib::file_architecture ($h, "/lib-sparc.so"),
-    "sparc");
-is (Sys::Guestfs::Lib::file_architecture ($h, "/lib-win32.dll"),
-    "i386");
-is (Sys::Guestfs::Lib::file_architecture ($h, "/lib-win64.dll"),
-    "x86_64");
-is (Sys::Guestfs::Lib::file_architecture ($h, "/lib-x86_64.so"),
-    "x86_64");
-is (Sys::Guestfs::Lib::file_architecture ($h, "/initrd-x86_64.img"),
-    "x86_64");
-is (Sys::Guestfs::Lib::file_architecture ($h, "/initrd-x86_64.img.gz"),
-    "x86_64");
diff --git a/po/POTFILES.in b/po/POTFILES.in
index fdc2b70..bf066ea 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -102,6 +102,7 @@ ruby/ext/guestfs/_guestfs.c
 src/actions.c
 src/bindtests.c
 src/guestfs.c
+src/inspect.c
 src/launch.c
 src/proto.c
 test-tool/helper.c
diff --git a/src/Makefile.am b/src/Makefile.am
index 4135c8c..9582c78 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -126,11 +126,12 @@ libguestfs_la_SOURCES = \
 	gettext.h \
 	actions.c \
 	bindtests.c \
+	inspect.c \
 	launch.c \
 	proto.c \
 	libguestfs.syms
 
-libguestfs_la_LIBADD = $(LTLIBTHREAD) ../gnulib/lib/libgnu.la
+libguestfs_la_LIBADD = $(LIBPCRE) $(LTLIBTHREAD) ../gnulib/lib/libgnu.la
 
 # Make libguestfs include the convenience library.
 noinst_LTLIBRARIES = libprotocol.la
diff --git a/src/generator.ml b/src/generator.ml
index d537945..04a675a 100755
--- a/src/generator.ml
+++ b/src/generator.ml
@@ -940,6 +940,134 @@ to specify the QEMU interface emulation to use at run time.");
 This is the same as C<guestfs_add_drive_ro> but it allows you
 to specify the QEMU interface emulation to use at run time.");
 
+  ("file_architecture", (RString "arch", [Pathname "filename"]), -1, [],
+   [InitISOFS, Always, TestOutput (
+      [["file_architecture"; "/bin-i586-dynamic"]], "i386");
+    InitISOFS, Always, TestOutput (
+      [["file_architecture"; "/bin-sparc-dynamic"]], "sparc");
+    InitISOFS, Always, TestOutput (
+      [["file_architecture"; "/bin-win32.exe"]], "i386");
+    InitISOFS, Always, TestOutput (
+      [["file_architecture"; "/bin-win64.exe"]], "x86_64");
+    InitISOFS, Always, TestOutput (
+      [["file_architecture"; "/bin-x86_64-dynamic"]], "x86_64");
+    InitISOFS, Always, TestOutput (
+      [["file_architecture"; "/lib-i586.so"]], "i386");
+    InitISOFS, Always, TestOutput (
+      [["file_architecture"; "/lib-sparc.so"]], "sparc");
+    InitISOFS, Always, TestOutput (
+      [["file_architecture"; "/lib-win32.dll"]], "i386");
+    InitISOFS, Always, TestOutput (
+      [["file_architecture"; "/lib-win64.dll"]], "x86_64");
+    InitISOFS, Always, TestOutput (
+      [["file_architecture"; "/lib-x86_64.so"]], "x86_64");
+    InitISOFS, Always, TestOutput (
+      [["file_architecture"; "/initrd-x86_64.img"]], "x86_64");
+    InitISOFS, Always, TestOutput (
+      [["file_architecture"; "/initrd-x86_64.img.gz"]], "x86_64");],
+   "detect the architecture of a binary file",
+   "\
+This detects the architecture of the binary C<filename>,
+and returns it if known.
+
+Currently defined architectures are:
+
+=over 4
+
+=item \"i386\"
+
+This string is returned for all 32 bit i386, i486, i586, i686 binaries
+irrespective of the precise processor requirements of the binary.
+
+=item \"x86_64\"
+
+64 bit x86-64.
+
+=item \"sparc\"
+
+32 bit SPARC.
+
+=item \"sparc64\"
+
+64 bit SPARC V9 and above.
+
+=item \"ia64\"
+
+Intel Itanium.
+
+=item \"ppc\"
+
+32 bit Power PC.
+
+=item \"ppc64\"
+
+64 bit Power PC.
+
+=back
+
+Libguestfs may return other architecture strings in future.
+
+The function works on at least the following types of files:
+
+=over 4
+
+=item *
+
+many types of Un*x and Linux binary
+
+=item *
+
+many types of Un*x and Linux shared library
+
+=item *
+
+Windows Win32 and Win64 binaries
+
+=item *
+
+Windows Win32 and Win64 DLLs
+
+Win32 binaries and DLLs return C<i386>.
+
+Win64 binaries and DLLs return C<x86_64>.
+
+=item *
+
+Linux kernel modules
+
+=item *
+
+Linux new-style initrd images
+
+=item *
+
+some non-x86 Linux vmlinuz kernels
+
+=back
+
+What it can't do currently:
+
+=over 4
+
+=item *
+
+static libraries (libfoo.a)
+
+=item *
+
+Linux old-style initrd as compressed ext2 filesystem (RHEL 3)
+
+=item *
+
+x86 Linux vmlinuz kernels
+
+x86 vmlinuz images (bzImage format) consist of a mix of 16-, 32- and
+compressed code, and are horribly hard to unpack.  If you want to find
+the architecture of a kernel, use the architecture of the associated
+initrd or kernel module(s) instead.
+
+=back");
+
 ]
 
 (* daemon_functions are any functions which cause some action
diff --git a/src/inspect.c b/src/inspect.c
new file mode 100644
index 0000000..8e28d8a
--- /dev/null
+++ b/src/inspect.c
@@ -0,0 +1,266 @@
+/* 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 "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_file_win64, "PE32\\+ executable", 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 (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, 30);
+  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 (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, 30);
+  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 strndup (&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 (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. */
+#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 18
+  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)) {
+      snprintf (cmd, dir_len + 256, "file %s", bin);
+      FILE *fp = popen (cmd, "r");
+      if (!fp) {
+        perrorf (g, "popen: %s", cmd);
+        goto out;
+      }
+
+      char line[1024];
+      if (!fgets (line, sizeof line, fp)) {
+        perrorf (g, "fgets");
+        fclose (fp);
+        goto out;
+      }
+      pclose (fp);
+
+      char *elf_arch;
+      if ((elf_arch = match1 (line, re_file_elf)) != NULL) {
+        ret = canonical_elf_arch (g, elf_arch);
+        free (elf_arch);
+        goto out;
+      }
+    }
+  }
+  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 (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 (match (file, re_file_win64))
+    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 */
+}
-- 
1.7.1


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