[PATCH 1 of 3] libxl: Look for bootloader in libexec path

[George Dunlap <george.dunlap@eu.citrix.com>]

If the full path for a bootloader (such as pygrub or xenpvnetboot) is not
given, look for it in the libexec path.

Signed-off-by: George Dunlap <george.dunlap@eu.citrix.com>

diff -r b4cbf273b1cb -r b810908dea7d tools/libxl/libxl_bootloader.c
--- a/tools/libxl/libxl_bootloader.c	Wed Feb 29 16:30:34 2012 +0000
+++ b/tools/libxl/libxl_bootloader.c	Thu Apr 26 15:09:35 2012 +0100
@@ -333,6 +333,7 @@ int libxl_run_bootloader(libxl_ctx *ctx,
 
     char tempdir_template[] = "/var/run/libxl/bl.XXXXXX";
     char *tempdir;
+    const char *bootloader = NULL;
 
     char *dom_console_xs_path;
     char dom_console_slave_tty_path[PATH_MAX];
@@ -397,6 +398,13 @@ int libxl_run_bootloader(libxl_ctx *ctx,
         goto out_close;
     }
 
+    bootloader = libxl__abs_path(gc, info->u.pv.bootloader,
+                                 libxl__libexec_path());
+    if ( bootloader == NULL ) {
+        rc = ERROR_NOMEM;
+        goto out_close;
+    }
+
     /*
      * We need to present the bootloader's tty as a pty slave that xenconsole
      * can access.  Since the bootloader itself needs a pty slave,
@@ -417,7 +425,7 @@ int libxl_run_bootloader(libxl_ctx *ctx,
     dom_console_xs_path = libxl__sprintf(gc, "%s/console/tty", libxl__xs_get_dompath(gc, domid));
     libxl__xs_write(gc, XBT_NULL, dom_console_xs_path, "%s", dom_console_slave_tty_path);
 
-    pid = fork_exec_bootloader(&bootloader_fd, info->u.pv.bootloader, args);
+    pid = fork_exec_bootloader(&bootloader_fd, bootloader, args);
     if (pid < 0) {
         goto out_close;
     }