From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Ian Page Hands <iphands@gmail.com>
Date: Tue, 8 Jun 2021 13:48:56 -0400
Subject: [PATCH] efinet: Add DHCP proxy support

If a proxyDHCP configuration is used, the server name, server IP and boot
file values should be taken from the DHCP proxy offer instead of the DHCP
server ack packet. Currently that case is not handled, add support for it.
---
 grub-core/net/drivers/efi/efinet.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/grub-core/net/drivers/efi/efinet.c b/grub-core/net/drivers/efi/efinet.c
index e11d759f19a..1a24f38a21a 100644
--- a/grub-core/net/drivers/efi/efinet.c
+++ b/grub-core/net/drivers/efi/efinet.c
@@ -850,10 +850,31 @@ grub_efi_net_config_real (grub_efi_handle_t hnd, char **device,
     else
       {
 	grub_dprintf ("efinet", "using ipv4 and dhcp\n");
+
+        struct grub_net_bootp_packet *dhcp_ack = &pxe_mode->dhcp_ack;
+
+        if (pxe_mode->proxy_offer_received)
+          {
+            grub_dprintf ("efinet", "proxy offer receive");
+            struct grub_net_bootp_packet *proxy_offer = &pxe_mode->proxy_offer;
+
+            if (proxy_offer && dhcp_ack->boot_file[0] == '\0')
+              {
+                grub_dprintf ("efinet", "setting values from proxy offer");
+                /* Here we got a proxy offer and the dhcp_ack has a nil boot_file
+                 * Copy the proxy DHCP offer details into the bootp_packet we are
+                 * sending forward as they are the deatils we need.
+                 */
+                *dhcp_ack->server_name = *proxy_offer->server_name;
+                *dhcp_ack->boot_file   = *proxy_offer->boot_file;
+                dhcp_ack->server_ip    = proxy_offer->server_ip;
+              }
+          }
+
 	grub_net_configure_by_dhcp_ack (card->name, card, 0,
 					(struct grub_net_bootp_packet *)
-					packet_buf,
-					packet_bufsz,
+					&pxe_mode->dhcp_ack,
+					sizeof (pxe_mode->dhcp_ack),
 					1, device, path);
 	grub_dprintf ("efinet", "device: `%s' path: `%s'\n", *device, *path);
       }