Add 'initrd-list' command to list contents of initrd images.

Add 'initrd-list' command to list the files inside (new-style)
initrd images.  Update virt-inspector to use this instead of
the less efficient download/unpack locally method.

.gitignore

@@ -67,6 +67,7 @@ images/100kallnewlines
 images/100kallspaces
 images/100krandom
 images/10klines
+images/initrd
 images/test.sqsh
 initramfs
 initramfs.timestamp

daemon/Makefile.am

@@ -43,6 +43,7 @@ guestfsd_SOURCES = \
 	guestfsd.c \
 	headtail.c \
 	hexdump.c \
+	initrd.c \
 	ls.c \
 	lvm.c \
 	mount.c \

daemon/initrd.c

@@ -0,0 +1,88 @@
+/* libguestfs - the guestfsd daemon
+ * 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.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "../src/guestfs_protocol.h"
+#include "daemon.h"
+#include "actions.h"
+
+char **
+do_initrd_list (char *path)
+{
+  FILE *fp;
+  int len;
+  char *cmd;
+  char filename[PATH_MAX];
+  char **filenames = NULL;
+  int size = 0, alloc = 0;
+
+  NEED_ROOT (NULL);
+  ABS_PATH (path, NULL);
+
+  /* "zcat /sysroot/<path> | cpio --quiet -it", but path must be quoted. */
+  len = 64 + 2 * strlen (path);
+  cmd = malloc (len);
+  if (!cmd) {
+    reply_with_perror ("malloc");
+    return NULL;
+  }
+
+  strcpy (cmd, "zcat /sysroot");
+  shell_quote (cmd+13, len-13, path);
+  strcat (cmd, " | cpio --quiet -it");
+
+  fprintf (stderr, "%s\n", cmd);
+
+  fp = popen (cmd, "r");
+  if (fp == NULL) {
+    reply_with_perror ("popen: %s", cmd);
+    free (cmd);
+    return NULL;
+  }
+  free (cmd);
+
+  while (fgets (filename, sizeof filename, fp) != NULL) {
+    len = strlen (filename);
+    if (len > 0 && filename[len-1] == '\n')
+      filename[len-1] = '\0';
+
+    if (add_string (&filenames, &size, &alloc, filename) == -1) {
+      pclose (fp);
+      return NULL;
+    }
+  }
+
+  if (add_string (&filenames, &size, &alloc, NULL) == -1) {
+    pclose (fp);
+    return NULL;
+  }
+
+  if (pclose (fp) == -1) {
+    reply_with_perror ("pclose");
+    free_strings (filenames);
+    return NULL;
+  }
+
+  return filenames;
+}

images/Makefile.am

@@ -26,7 +26,8 @@ noinst_DATA = test.sqsh
 CLEANFILES = test.sqsh
 
 squash_files = helloworld.tar helloworld.tar.gz empty known-1 known-2 known-3 \
-	100kallzeroes 100kallnewlines 100kallspaces 100krandom 10klines
+	100kallzeroes 100kallnewlines 100kallspaces 100krandom 10klines \
+	initrd
 
 test.sqsh: $(squash_files)
 	rm -f $@
@@ -60,3 +61,8 @@ test.sqsh: $(squash_files)
 	  i=$$(($$i+1)); \
 	done > $@-t
 	mv $@-t $@
+
+initrd: empty known-1 known-2 known-3
+	rm -f $@ $@-t
+	for f in $^; do echo $$f; done | cpio -o -H newc | gzip --best > $@-t
+	mv $@-t $@

inspector/virt-inspector.pl

@@ -727,9 +727,6 @@ sub find_filesystem
 # we don't need to know.
 
 if ($output !~ /.*fish$/) {
-    # Temporary directory for use by check_for_initrd.
-    my $dir = tempdir (CLEANUP => 1);
-
     my $root_dev;
     foreach $root_dev (sort keys %oses) {
 	my $mounts = $oses{$root_dev}->{mounts};
@@ -744,7 +741,7 @@ if ($output !~ /.*fish$/) {
 	check_for_kernels ($root_dev);
 	if ($oses{$root_dev}->{os} eq "linux") {
 	    check_for_modprobe_aliases ($root_dev);
-	    check_for_initrd ($root_dev, $dir);
+	    check_for_initrd ($root_dev);
 	}
 
 	$g->umount_all ();
@@ -898,42 +895,22 @@ sub check_for_initrd
 {
     local $_;
     my $root_dev = shift;
-    my $dir = shift;
 
     my %initrd_modules;
 
     foreach my $initrd ($g->ls ("/boot")) {
 	if ($initrd =~ m/^initrd-(.*)\.img$/ && $g->is_file ("/boot/$initrd")) {
 	    my $version = $1;
-	    my @modules = ();
-	    # We have to download these to a temporary file.
-	    $g->download ("/boot/$initrd", "$dir/initrd");
+	    my @modules;
 
-	    my $cmd = "zcat $dir/initrd | file -";
-	    open P, "$cmd |" or die "$cmd: $!";
-	    my $lines;
-	    { local $/ = undef; $lines = <P>; }
-	    close P;
-	    if ($lines =~ /ext\d filesystem data/) {
-		# Before initramfs came along, these were compressed
-		# ext2 filesystems.  We could run another libguestfs
-		# instance to unpack these, but punt on them for now. (XXX)
-		warn "initrd image is unsupported ext2/3/4 filesystem\n";
-	    }
-	    elsif ($lines =~ /cpio/) {
-		my $cmd = "zcat $dir/initrd | cpio --quiet -it";
-		open P, "$cmd |" or die "$cmd: $!";
-		while (<P>) {
-		    push @modules, $1
-			if m,([^/]+)\.ko$, || m,([^/]+)\.o$,;
-		}
-		close P;
-		unlink "$dir/initrd";
-		$initrd_modules{$version} = \@modules;
-	    }
-	    else {
-		# What?
-		warn "unrecognized initrd image: $lines\n";
+	    eval {
+		@modules = $g->initrd_list ("/boot/$initrd");
+	    };
+	    unless ($@) {
+		@modules = grep { m,([^/]+)\.ko$, || m,([^/]+)\.o$, } @modules;
+		$initrd_modules{$version} = \@modules
+	    } else {
+		warn "/boot/$initrd: could not read initrd format"
 	    }
 	}
     }

src/generator.ml

@@ -2599,6 +2599,22 @@ subdirectories (recursively).
 The result is the estimated size in I<kilobytes>
 (ie. units of 1024 bytes).");
 
+  ("initrd_list", (RStringList "filenames", [String "path"]), 128, [],
+   [InitBasicFS, Always, TestOutputList (
+      [["mount_vfs"; "ro"; "squashfs"; "/dev/sdd"; "/"];
+       ["initrd_list"; "/initrd"]], ["empty";"known-1";"known-2";"known-3"])],
+   "list files in an initrd",
+   "\
+This command lists out files contained in an initrd.
+
+The files are listed without any initial C</> character.  The
+files are listed in the order they appear (not necessarily
+alphabetical).  Directory names are listed as separate items.
+
+Old Linux kernels (2.4 and earlier) used a compressed ext2
+filesystem as initrd.  We I<only> support the newer initramfs
+format (compressed cpio files).");
+
 ]
 
 let all_functions = non_daemon_functions @ daemon_functions