Signed-off-by: Michael Tremer michael.tremer@ipfire.org --- lfs/dhcpcd | 1 + ...ow-free-selection-of-MTU-by-the-user.patch | 44 +++++++++++++++++++ 2 files changed, 45 insertions(+) create mode 100644 src/patches/dhcpcd-9.4.0-Allow-free-selection-of-MTU-by-the-user.patch
diff --git a/lfs/dhcpcd b/lfs/dhcpcd index 8291d076a..03349ddc7 100644 --- a/lfs/dhcpcd +++ b/lfs/dhcpcd @@ -70,6 +70,7 @@ $(subst %,%_MD5,$(objects)) : $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects)) @$(PREBUILD) @rm -rf $(DIR_APP) && cd $(DIR_SRC) && tar axf $(DIR_DL)/$(DL_FILE) + cd $(DIR_APP) && patch -Np1 < $(DIR_SRC)/src/patches/dhcpcd-9.4.0-Allow-free-selection-of-MTU-by-the-user.patch cd $(DIR_APP) && ./configure \ --prefix="" \ --sysconfdir=/var/ipfire/dhcpc \ diff --git a/src/patches/dhcpcd-9.4.0-Allow-free-selection-of-MTU-by-the-user.patch b/src/patches/dhcpcd-9.4.0-Allow-free-selection-of-MTU-by-the-user.patch new file mode 100644 index 000000000..69a35daf5 --- /dev/null +++ b/src/patches/dhcpcd-9.4.0-Allow-free-selection-of-MTU-by-the-user.patch @@ -0,0 +1,44 @@ +From 1acff721a3874a74efc9921a1e07bd48bd7efab0 Mon Sep 17 00:00:00 2001 +From: Michael Tremer michael.tremer@ipfire.org +Date: Tue, 22 Feb 2022 12:07:15 +0000 +Subject: [PATCH] Allow free selection of MTU by the user + +Various ISPs (or equipment?) seem to hand out an MTU of only 576 bytes. +Hwoever, this does not seem to be intentional which is why we would like +to manually overwrite this in the configuration. + +dhcpcd only allows setting a maximum MTU of 1472 bytes which does not +seem to have any rationale (any more). Although Ethernet might limit any +MTU to less, IPv6 and IPv4 support MTUs of up to 64KiB. + +This patch allows the user to configure the MTU freely with providing +some sanity check. + +Signed-off-by: Michael Tremer michael.tremer@ipfire.org +--- + src/dhcp-common.h | 9 +++++---- + 1 file changed, 5 insertions(+), 4 deletions(-) + +diff --git a/src/dhcp-common.h b/src/dhcp-common.h +index a82fcd4c..d6620822 100644 +--- a/src/dhcp-common.h ++++ b/src/dhcp-common.h +@@ -46,10 +46,11 @@ + #define NS_MAXLABEL MAXLABEL + #endif + +-/* Max MTU - defines dhcp option length */ +-#define IP_UDP_SIZE 28 +-#define MTU_MAX 1500 - IP_UDP_SIZE +-#define MTU_MIN 576 + IP_UDP_SIZE ++/* Max/Min MTU */ ++#define MTU_MAX 65536 ++#define MTU_MIN 576 ++ ++#define IP_UDP_SIZE 28 + + #define OT_REQUEST (1 << 0) + #define OT_UINT8 (1 << 1) +-- +2.30.2 +