* [PATCH 1/3] dhcpcd: Force setting MTU through dhcpcd
@ 2022-02-22 12:18 Michael Tremer
2022-02-22 12:18 ` [PATCH 2/3] dhcpcd: Remove old MTU setting script Michael Tremer
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Michael Tremer @ 2022-02-22 12:18 UTC (permalink / raw)
To: development
[-- Attachment #1: Type: text/plain, Size: 1707 bytes --]
The DHCP server can instruct clients to configure a certain MTU.
This used to be done by setting the MTU of the interface. However,
dhcpcd has changed this behaviour using routes to.
We used to have a modified version of the old mechanism which no longer
works well with the new system and is therefore to be dropped.
This is the first commit in the series implementing the new behaviour
and telling dhcpcd to use the configured MTU.
Fixes: #12563
Signed-off-by: Michael Tremer <michael.tremer(a)ipfire.org>
---
src/initscripts/networking/functions.network | 11 ++++++++---
1 file changed, 8 insertions(+), 3 deletions(-)
diff --git a/src/initscripts/networking/functions.network b/src/initscripts/networking/functions.network
index 7ec50f436..eae4a7b7c 100644
--- a/src/initscripts/networking/functions.network
+++ b/src/initscripts/networking/functions.network
@@ -61,7 +61,7 @@ dhcpcd_start() {
# This function will start a dhcpcd on a speciefied device.
local device="$1"
- local dhcp_start=""
+ local dhcp_start=()
boot_mesg -n "Starting dhcpcd on the ${device} interface..."
@@ -76,11 +76,16 @@ dhcpcd_start() {
# Check if a DHCP hostname has been set.
if [ -n "${RED_DHCP_HOSTNAME}" ]; then
- dhcp_start+="-h ${RED_DHCP_HOSTNAME}"
+ dhcp_start+=( "-h" "${RED_DHCP_HOSTNAME}" )
+ fi
+
+ # Tell dhcpcd to use the configured MTU
+ if [ -n "${RED_DHCP_FORCE_MTU}" ]; then
+ dhcp_start+=( "--static" "mtu=${RED_DHCP_FORCE_MTU}" )
fi
# Start dhcpcd.
- /sbin/dhcpcd ${dhcp_start} ${device} >/dev/null 2>&1
+ /sbin/dhcpcd "${dhcp_start[@]}" ${device} >/dev/null 2>&1
ret="$?"
if [ "${ret}" -eq 0 ]; then
--
2.30.2
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 2/3] dhcpcd: Remove old MTU setting script
2022-02-22 12:18 [PATCH 1/3] dhcpcd: Force setting MTU through dhcpcd Michael Tremer
@ 2022-02-22 12:18 ` Michael Tremer
2022-02-22 19:16 ` Peter Müller
2022-02-22 12:18 ` [PATCH 3/3] dhcpcd: Allow freely setting MTU Michael Tremer
2022-02-22 19:16 ` [PATCH 1/3] dhcpcd: Force setting MTU through dhcpcd Peter Müller
2 siblings, 1 reply; 6+ messages in thread
From: Michael Tremer @ 2022-02-22 12:18 UTC (permalink / raw)
To: development
[-- Attachment #1: Type: text/plain, Size: 2511 bytes --]
This is being replaced by adding the MTU option to any routes that
dhcpcd installs.
Signed-off-by: Michael Tremer <michael.tremer(a)ipfire.org>
---
config/dhcpc/dhcpcd-hooks/10-mtu | 33 --------------------------------
config/rootfiles/common/dhcpcd | 1 -
lfs/dhcpcd | 1 -
3 files changed, 35 deletions(-)
delete mode 100644 config/dhcpc/dhcpcd-hooks/10-mtu
diff --git a/config/dhcpc/dhcpcd-hooks/10-mtu b/config/dhcpc/dhcpcd-hooks/10-mtu
deleted file mode 100644
index 8eb429751..000000000
--- a/config/dhcpc/dhcpcd-hooks/10-mtu
+++ /dev/null
@@ -1,33 +0,0 @@
-# Configure the MTU for the interface
-
-eval $(/usr/local/bin/readhash /var/ipfire/ethernet/settings)
-
-set_mtu()
-{
- local mtu=$1
- ip link set "$interface" mtu "$mtu"
-
- # test for buggy nic that lose link at mtu set...
- carrier=`cat /sys/class/net/$interface/carrier`
- if [ "$carrier" == "0" ]; then
- syslog info "Warning! Carrier loss after MTU set. Reinit needed..."
- ip link set "$interface" down
- ip link set "$interface" up
- exit 1
- fi
-}
-
-if [ -n "$new_interface_mtu" ] && $if_up; then
- if [ $RED_DHCP_FORCE_MTU -ge 576 ]; then
- new_interface_mtu=$RED_DHCP_FORCE_MTU
- fi
- if [ ! "$new_interface_mtu" == "$ifmtu" ]; then
- # The smalled MTU dhcpcd can work with is 576
- if [ "$new_interface_mtu" -gt 576 ]; then
- if set_mtu "$new_interface_mtu"; then
- syslog info "MTU set to $new_interface_mtu"
- fi
- fi
- fi
-fi
-
diff --git a/config/rootfiles/common/dhcpcd b/config/rootfiles/common/dhcpcd
index 672a47a30..d36b105f1 100644
--- a/config/rootfiles/common/dhcpcd
+++ b/config/rootfiles/common/dhcpcd
@@ -9,7 +9,6 @@ var/ipfire/dhcpc/dhcpcd-hooks
#var/ipfire/dhcpc/dhcpcd-hooks/00-linux
#var/ipfire/dhcpc/dhcpcd-hooks/01-test
#var/ipfire/dhcpc/dhcpcd-hooks/02-dump
-#var/ipfire/dhcpc/dhcpcd-hooks/10-mtu
#var/ipfire/dhcpc/dhcpcd-hooks/30-hostname
#var/ipfire/dhcpc/dhcpcd-hooks/70-dhcpcd.exe
var/ipfire/dhcpc/dhcpcd-run-hooks
diff --git a/lfs/dhcpcd b/lfs/dhcpcd
index 8c4a593ad..8291d076a 100644
--- a/lfs/dhcpcd
+++ b/lfs/dhcpcd
@@ -90,7 +90,6 @@ $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects))
rm -f $(CONFIG_ROOT)/dhcpc/dhcpcd-hooks/50-ypbind
install -m 644 $(DIR_SRC)/config/dhcpc/dhcpcd.conf $(CONFIG_ROOT)/dhcpc/
- install -m 444 $(DIR_SRC)/config/dhcpc/dhcpcd-hooks/10-mtu $(CONFIG_ROOT)/dhcpc/dhcpcd-hooks
chown root:root $(CONFIG_ROOT)/dhcpc/dhcpcd.conf
--
2.30.2
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 3/3] dhcpcd: Allow freely setting MTU
2022-02-22 12:18 [PATCH 1/3] dhcpcd: Force setting MTU through dhcpcd Michael Tremer
2022-02-22 12:18 ` [PATCH 2/3] dhcpcd: Remove old MTU setting script Michael Tremer
@ 2022-02-22 12:18 ` Michael Tremer
2022-02-22 19:17 ` Peter Müller
2022-02-22 19:16 ` [PATCH 1/3] dhcpcd: Force setting MTU through dhcpcd Peter Müller
2 siblings, 1 reply; 6+ messages in thread
From: Michael Tremer @ 2022-02-22 12:18 UTC (permalink / raw)
To: development
[-- Attachment #1: Type: text/plain, Size: 2607 bytes --]
Signed-off-by: Michael Tremer <michael.tremer(a)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(a)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(a)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
+
--
2.30.2
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 1/3] dhcpcd: Force setting MTU through dhcpcd
2022-02-22 12:18 [PATCH 1/3] dhcpcd: Force setting MTU through dhcpcd Michael Tremer
2022-02-22 12:18 ` [PATCH 2/3] dhcpcd: Remove old MTU setting script Michael Tremer
2022-02-22 12:18 ` [PATCH 3/3] dhcpcd: Allow freely setting MTU Michael Tremer
@ 2022-02-22 19:16 ` Peter Müller
2 siblings, 0 replies; 6+ messages in thread
From: Peter Müller @ 2022-02-22 19:16 UTC (permalink / raw)
To: development
[-- Attachment #1: Type: text/plain, Size: 1866 bytes --]
Reviewed-by: Peter Müller <peter.mueller(a)ipfire.org>
> The DHCP server can instruct clients to configure a certain MTU.
>
> This used to be done by setting the MTU of the interface. However,
> dhcpcd has changed this behaviour using routes to.
>
> We used to have a modified version of the old mechanism which no longer
> works well with the new system and is therefore to be dropped.
>
> This is the first commit in the series implementing the new behaviour
> and telling dhcpcd to use the configured MTU.
>
> Fixes: #12563
> Signed-off-by: Michael Tremer <michael.tremer(a)ipfire.org>
> ---
> src/initscripts/networking/functions.network | 11 ++++++++---
> 1 file changed, 8 insertions(+), 3 deletions(-)
>
> diff --git a/src/initscripts/networking/functions.network b/src/initscripts/networking/functions.network
> index 7ec50f436..eae4a7b7c 100644
> --- a/src/initscripts/networking/functions.network
> +++ b/src/initscripts/networking/functions.network
> @@ -61,7 +61,7 @@ dhcpcd_start() {
> # This function will start a dhcpcd on a speciefied device.
>
> local device="$1"
> - local dhcp_start=""
> + local dhcp_start=()
>
> boot_mesg -n "Starting dhcpcd on the ${device} interface..."
>
> @@ -76,11 +76,16 @@ dhcpcd_start() {
>
> # Check if a DHCP hostname has been set.
> if [ -n "${RED_DHCP_HOSTNAME}" ]; then
> - dhcp_start+="-h ${RED_DHCP_HOSTNAME}"
> + dhcp_start+=( "-h" "${RED_DHCP_HOSTNAME}" )
> + fi
> +
> + # Tell dhcpcd to use the configured MTU
> + if [ -n "${RED_DHCP_FORCE_MTU}" ]; then
> + dhcp_start+=( "--static" "mtu=${RED_DHCP_FORCE_MTU}" )
> fi
>
> # Start dhcpcd.
> - /sbin/dhcpcd ${dhcp_start} ${device} >/dev/null 2>&1
> + /sbin/dhcpcd "${dhcp_start[@]}" ${device} >/dev/null 2>&1
> ret="$?"
>
> if [ "${ret}" -eq 0 ]; then
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/3] dhcpcd: Remove old MTU setting script
2022-02-22 12:18 ` [PATCH 2/3] dhcpcd: Remove old MTU setting script Michael Tremer
@ 2022-02-22 19:16 ` Peter Müller
0 siblings, 0 replies; 6+ messages in thread
From: Peter Müller @ 2022-02-22 19:16 UTC (permalink / raw)
To: development
[-- Attachment #1: Type: text/plain, Size: 2720 bytes --]
Reviewed-by: Peter Müller <peter.mueller(a)ipfire.org>
> This is being replaced by adding the MTU option to any routes that
> dhcpcd installs.
>
> Signed-off-by: Michael Tremer <michael.tremer(a)ipfire.org>
> ---
> config/dhcpc/dhcpcd-hooks/10-mtu | 33 --------------------------------
> config/rootfiles/common/dhcpcd | 1 -
> lfs/dhcpcd | 1 -
> 3 files changed, 35 deletions(-)
> delete mode 100644 config/dhcpc/dhcpcd-hooks/10-mtu
>
> diff --git a/config/dhcpc/dhcpcd-hooks/10-mtu b/config/dhcpc/dhcpcd-hooks/10-mtu
> deleted file mode 100644
> index 8eb429751..000000000
> --- a/config/dhcpc/dhcpcd-hooks/10-mtu
> +++ /dev/null
> @@ -1,33 +0,0 @@
> -# Configure the MTU for the interface
> -
> -eval $(/usr/local/bin/readhash /var/ipfire/ethernet/settings)
> -
> -set_mtu()
> -{
> - local mtu=$1
> - ip link set "$interface" mtu "$mtu"
> -
> - # test for buggy nic that lose link at mtu set...
> - carrier=`cat /sys/class/net/$interface/carrier`
> - if [ "$carrier" == "0" ]; then
> - syslog info "Warning! Carrier loss after MTU set. Reinit needed..."
> - ip link set "$interface" down
> - ip link set "$interface" up
> - exit 1
> - fi
> -}
> -
> -if [ -n "$new_interface_mtu" ] && $if_up; then
> - if [ $RED_DHCP_FORCE_MTU -ge 576 ]; then
> - new_interface_mtu=$RED_DHCP_FORCE_MTU
> - fi
> - if [ ! "$new_interface_mtu" == "$ifmtu" ]; then
> - # The smalled MTU dhcpcd can work with is 576
> - if [ "$new_interface_mtu" -gt 576 ]; then
> - if set_mtu "$new_interface_mtu"; then
> - syslog info "MTU set to $new_interface_mtu"
> - fi
> - fi
> - fi
> -fi
> -
> diff --git a/config/rootfiles/common/dhcpcd b/config/rootfiles/common/dhcpcd
> index 672a47a30..d36b105f1 100644
> --- a/config/rootfiles/common/dhcpcd
> +++ b/config/rootfiles/common/dhcpcd
> @@ -9,7 +9,6 @@ var/ipfire/dhcpc/dhcpcd-hooks
> #var/ipfire/dhcpc/dhcpcd-hooks/00-linux
> #var/ipfire/dhcpc/dhcpcd-hooks/01-test
> #var/ipfire/dhcpc/dhcpcd-hooks/02-dump
> -#var/ipfire/dhcpc/dhcpcd-hooks/10-mtu
> #var/ipfire/dhcpc/dhcpcd-hooks/30-hostname
> #var/ipfire/dhcpc/dhcpcd-hooks/70-dhcpcd.exe
> var/ipfire/dhcpc/dhcpcd-run-hooks
> diff --git a/lfs/dhcpcd b/lfs/dhcpcd
> index 8c4a593ad..8291d076a 100644
> --- a/lfs/dhcpcd
> +++ b/lfs/dhcpcd
> @@ -90,7 +90,6 @@ $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects))
> rm -f $(CONFIG_ROOT)/dhcpc/dhcpcd-hooks/50-ypbind
>
> install -m 644 $(DIR_SRC)/config/dhcpc/dhcpcd.conf $(CONFIG_ROOT)/dhcpc/
> - install -m 444 $(DIR_SRC)/config/dhcpc/dhcpcd-hooks/10-mtu $(CONFIG_ROOT)/dhcpc/dhcpcd-hooks
>
> chown root:root $(CONFIG_ROOT)/dhcpc/dhcpcd.conf
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 3/3] dhcpcd: Allow freely setting MTU
2022-02-22 12:18 ` [PATCH 3/3] dhcpcd: Allow freely setting MTU Michael Tremer
@ 2022-02-22 19:17 ` Peter Müller
0 siblings, 0 replies; 6+ messages in thread
From: Peter Müller @ 2022-02-22 19:17 UTC (permalink / raw)
To: development
[-- Attachment #1: Type: text/plain, Size: 2796 bytes --]
Reviewed-by: Peter Müller <peter.mueller(a)ipfire.org>
> Signed-off-by: Michael Tremer <michael.tremer(a)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(a)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(a)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
> +
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-02-22 19:17 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2022-02-22 12:18 [PATCH 1/3] dhcpcd: Force setting MTU through dhcpcd Michael Tremer
2022-02-22 12:18 ` [PATCH 2/3] dhcpcd: Remove old MTU setting script Michael Tremer
2022-02-22 19:16 ` Peter Müller
2022-02-22 12:18 ` [PATCH 3/3] dhcpcd: Allow freely setting MTU Michael Tremer
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