[PATCH v4 17/19] http: Prepend prefix when the HTTP path is relative

[Robbie Harwood]

From: Javier Martinez Canillas <javierm@redhat.com>

There are two different HTTP drivers that can be used when requesting an
HTTP resource: the efi/http that uses the EFI_HTTP_PROTOCOL and the http
that uses GRUB's HTTP and TCP/IP implementation.

The efi/http driver appends a prefix that is defined in the variable
http_path, but the http driver doesn't.  So using this driver and
attempting to fetch a resource using a relative path fails.  Match the
behavior of efi/http.

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Co-authored-by: Robbie Harwood <rharwood@redhat.com>
Signed-off-by: Robbie Harwood <rharwood@redhat.com>
---
 grub-core/net/http.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/grub-core/net/http.c b/grub-core/net/http.c
index f78adcd679..b044b324c5 100644
--- a/grub-core/net/http.c
+++ b/grub-core/net/http.c
@@ -16,6 +16,7 @@
  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <grub/env.h>
 #include <grub/misc.h>
 #include <grub/net/tcp.h>
 #include <grub/net/ip.h>
@@ -508,13 +509,20 @@ http_open (struct grub_file *file, const char *filename)
 {
   grub_err_t err;
   struct http_data *data;
+  const char *http_path;
 
   data = grub_zalloc (sizeof (*data));
   if (!data)
     return grub_errno;
   file->size = GRUB_FILE_SIZE_UNKNOWN;
 
-  data->filename = grub_strdup (filename);
+  /* If path is relative, prepend http_path */
+  http_path = grub_env_get ("http_path");
+  if (http_path && filename[0] != '/')
+    data->filename = grub_xasprintf ("%s/%s", http_path, filename);
+  else
+    data->filename = grub_strdup (filename);
+
   if (!data->filename)
     {
       grub_free (data);
-- 
2.39.0