+=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
+
+=cut
+
+sub _elf_arch_to_canonical
+{
+ local $_ = shift;
+
+ if ($_ eq "Intel 80386") {
+ return "i386";
+ } elsif ($_ eq "Intel 80486") {
+ return "i486"; # probably not in the wild
+ } elsif ($_ eq "x86-64") {
+ return "x86_64";
+ } elsif (/SPARC32/) {
+ return "sparc";
+ } elsif (/SPARC V9/) {
+ return "sparc64";
+ } elsif ($_ eq "IA-64") {
+ return "ia64";
+ } elsif (/64.*PowerPC/) {
+ return "ppc64";
+ } elsif (/PowerPC/) {
+ return "ppc";
+ } else {
+ warn __x("returning non-canonical architecture type '{arch}'",
+ arch => $_);
+ return $_;
+ }
+}
+
+my @_initrd_binaries = ("nash", "modprobe", "sh", "bash");
+
+sub file_architecture
+{
+ local $_;
+ my $g = shift;
+ my $path = shift;
+
+ # Our basic tool is 'file' ...
+ my $file = $g->file ($path);
+
+ if ($file =~ /ELF.*(?:executable|shared object|relocatable), (.+?),/) {
+ # ELF executable or shared object. We need to convert
+ # what file(1) prints into the canonical form.
+ return _elf_arch_to_canonical ($1);
+ } elsif ($file =~ /PE32 executable/) {
+ return "i386"; # Win32 executable or DLL
+ } elsif ($file =~ /PE32\+ executable/) {
+ return "x86_64"; # Win64 executable or DLL
+ }
+
+ elsif ($file =~ /cpio archive/) {
+ # Probably an initrd.
+ my $zcat = "cat";
+ if ($file =~ /gzip/) {
+ $zcat = "zcat";
+ } elsif ($file =~ /bzip2/) {
+ $zcat = "bzcat";
+ }
+
+ # Download and unpack it to find a binary file.
+ my $dir = tempdir (CLEANUP => 1);
+ $g->download ($path, "$dir/initrd");
+
+ my $bins = join " ", map { "bin/$_" } @_initrd_binaries;
+ my $cmd = "cd $dir && $zcat initrd | cpio -id $bins";
+ my $r = system ($cmd);
+ die __x("cpio command failed: {error}", error => $?)
+ unless $r == 0;
+
+ foreach my $bin (@_initrd_binaries) {
+ if (-f "$dir/bin/$bin") {
+ open PIPE, "file $dir/bin/$bin |";
+ local $/ = undef;
+ $_ = <PIPE>;
+ if (/ELF.*executable, (.+?),/) {
+ return _elf_arch_to_canonical ($1);
+ }
+ }
+ }
+
+ die __x("file_architecture: no known binaries found in initrd image: {path}",
+ path => $path);
+ }
+
+ die __x("file_architecture: unknown architecture: {path}",
+ path => $path);
+}
+
git.annexia.org / libguestfs.git / commitdiff