Fix TFTP timeouts when trying to fetch files larger than 65535 KiB

Resolves: rhbz#1869335

Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>

0064-efinet-and-bootp-add-support-for-dhcpv6.patch

@@ -399,7 +399,7 @@ index 4b7972b8e7e..f24f1fd63f6 100644
  grub_err_t
  grub_net_add_ipv4_local (struct grub_net_network_level_interface *inter,
 diff --git a/grub-core/net/tftp.c b/grub-core/net/tftp.c
-index 7d90bf66e76..1157524fc50 100644
+index 7d90bf66e76..a5c5038130a 100644
 --- a/grub-core/net/tftp.c
 +++ b/grub-core/net/tftp.c
 @@ -379,19 +379,23 @@ tftp_open (struct grub_file *file, const char *filename)

0066-Normalize-slashes-in-tftp-paths.patch

@@ -14,7 +14,7 @@ Signed-off-by: Mark Salter <msalter@redhat.com>
  1 file changed, 25 insertions(+), 3 deletions(-)
 
 diff --git a/grub-core/net/tftp.c b/grub-core/net/tftp.c
-index 1157524fc50..dcd82494309 100644
+index a5c5038130a..e6d831f1bc9 100644
 --- a/grub-core/net/tftp.c
 +++ b/grub-core/net/tftp.c
 @@ -300,6 +300,25 @@ destroy_pq (tftp_data_t data)

0086-don-t-ignore-const.patch

@@ -8,7 +8,7 @@ Subject: [PATCH] don't ignore const
  1 file changed, 1 insertion(+), 1 deletion(-)
 
 diff --git a/grub-core/net/tftp.c b/grub-core/net/tftp.c
-index dcd82494309..f90071353ad 100644
+index e6d831f1bc9..0c02a00255b 100644
 --- a/grub-core/net/tftp.c
 +++ b/grub-core/net/tftp.c
 @@ -307,7 +307,7 @@ static void

0111-net-read-bracketed-ipv6-addrs-and-port-numbers.patch

@@ -227,7 +227,7 @@ index 6468eb24596..2734f70d22f 100644
  }
  
 diff --git a/grub-core/net/tftp.c b/grub-core/net/tftp.c
-index f90071353ad..e267af354f4 100644
+index 0c02a00255b..4920c3a9783 100644
 --- a/grub-core/net/tftp.c
 +++ b/grub-core/net/tftp.c
 @@ -333,6 +333,7 @@ tftp_open (struct grub_file *file, const char *filename)

0238-tftp-Do-not-use-priority-queue.patch

@@ -35,7 +35,7 @@ Upstream-commit-id: 8316694c4f7
  1 file changed, 50 insertions(+), 112 deletions(-)
 
 diff --git a/grub-core/net/tftp.c b/grub-core/net/tftp.c
-index e267af354f4..c2df3d7f6ab 100644
+index 4920c3a9783..22badd74316 100644
 --- a/grub-core/net/tftp.c
 +++ b/grub-core/net/tftp.c
 @@ -25,7 +25,6 @@

0268-tftp-increase-blocksize-from-1024-to-2048-octets.patch

@@ -0,0 +1,47 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Javier Martinez Canillas <javierm@redhat.com>
+Date: Thu, 20 Aug 2020 13:19:00 +0200
+Subject: [PATCH] tftp: increase blocksize from 1024 to 2048 octets
+
+The RFC2348 [0] defines how the TFTP Blocksize Option should be negotiated
+between the client and the server. GRUB just hardcodes this to 1024, which
+limits the maximum file size to be fetched to 65535 KiB, since the block
+number is stored in a 16-bit field.
+
+This limit is a problem when attempting to fetch large files (i.e: initrd
+images) because the block number will overflow, and GRUB will never ack a
+packet. This causes a timeout when trying to download the file over TFTP.
+
+Since the TFTP support in GRUB is used primarily to fetch the kernel and
+initrd images, let's bump the blocksize to 2048 which would allow to get
+files twice as large than the current limit.
+
+The TFTP support should be improved to define the blocksize dynamically
+instead of hardcoding it, but until that happens is better to use a value
+that at least allows to fetch a kernel and initrd image with the size that
+are present in the install media that is used for network booting.
+
+[0]: https://tools.ietf.org/html/rfc2348
+
+Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
+---
+ grub-core/net/tftp.c | 6 +++---
+ 1 file changed, 3 insertions(+), 3 deletions(-)
+
+diff --git a/grub-core/net/tftp.c b/grub-core/net/tftp.c
+index 22badd74316..816050bca43 100644
+--- a/grub-core/net/tftp.c
++++ b/grub-core/net/tftp.c
+@@ -322,9 +322,9 @@ tftp_open (struct grub_file *file, const char *filename)
+   rrqlen += grub_strlen ("blksize") + 1;
+   rrq += grub_strlen ("blksize") + 1;
+ 
+-  grub_strcpy (rrq, "1024");
+-  rrqlen += grub_strlen ("1024") + 1;
+-  rrq += grub_strlen ("1024") + 1;
++  grub_strcpy (rrq, "2048");
++  rrqlen += grub_strlen ("2048") + 1;
++  rrq += grub_strlen ("2048") + 1;
+ 
+   grub_strcpy (rrq, "tsize");
+   rrqlen += grub_strlen ("tsize") + 1;

grub.patches

@@ -265,3 +265,4 @@ Patch0264: 0264-Fix-const-char-pointers-in-grub-core-net-efi-pxe.c.patch
 Patch0265: 0265-Fix-const-char-pointers-in-grub-core-net-url.c.patch
 Patch0266: 0266-Add-systemd-integration-scripts-to-make-systemctl-re.patch
 Patch0267: 0267-systemd-integration.sh-Also-set-old-menu_show_once-g.patch
+Patch0268: 0268-tftp-increase-blocksize-from-1024-to-2048-octets.patch

grub2.spec

@@ -14,7 +14,7 @@
 Name:		grub2
 Epoch:		1
 Version:	2.04
-Release:	28%{?dist}
+Release:	29%{?dist}
 Summary:	Bootloader with support for Linux, Multiboot and more
 License:	GPLv3+
 URL:		http://www.gnu.org/software/grub/
@@ -516,6 +516,10 @@ rm -r /boot/grub2.tmp/ || :
 %endif
 
 %changelog
+* Fri Aug 21 2020 Javier Martinez Canillas <javierm@redhat.com> - 2.04-29
+- Fix TFTP timeouts when trying to fetch files larger than 65535 KiB
+  Resolves: rhbz#1869335
+
 * Wed Aug 12 2020 Javier Martinez Canillas <javierm@redhat.com> - 2.04-28
 - Add support for "systemctl reboot --boot-loader-menu=xx" (hdegoede)
   Related: rhbz#1857389