path: root/package
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authorGravatar Thomas De Schampheleire <patrickdepinguin@gmail.com>2014-01-02 13:34:42 +0100
committerGravatar Thomas Petazzoni <thomas.petazzoni@free-electrons.com>2014-01-02 15:06:34 +0100
commitd6c096fd09219691c3f273aff298631b07c669e0 (patch)
treed090682d4ea1934a3c03418739bca674ad9a61ad /package
parent7a58a4ea6942c569999b53fb191e09b1756c3213 (diff)
dropbear: add support for custom arguments through config file
The default port 22 used by dropbear for its SSH connections is not always desired. Dropbear accepts an option '-p' to set the port, but doing this was not possible from the buildroot-provided init script. One way to fix this is by adding a custom S50dropbear in a project-specific rootfs overlay. However, this approach has the big disadvantage that bug fixes or improvements in the default init script (i.e. in newer buildroot releases) are not available (unless you manually port these changes each time you upgrade buildroot). Another solution is to modify the default init script from a project-specific post-build script. However, this is fragile because you'd have to sed some line but this line may change in later buildroot releases. Yet another solution is to change the default port at build time, by patching the options.h header file in the dropbear sources. This was proposed with a patch [1] before, but not accepted. This patch implements another solution, hinted from the discussion in [1]: the default init script now sources a config file /etc/default/dropbear, in which the user can set the variable DROPBEAR_ARGS. This is similar to the S81named init script in the bind package. The config file would be added to a project-specific rootfs overlay, a custom skeleton, or created from a post-build script. This approach has the advantage of being simple and non-intrusive, without any code duplication or fragile script modifications. [1] http://lists.busybox.net/pipermail/buildroot/2013-November/083165.html Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com> Reviewed-by: "Yann E. MORIN" <yann.morin.1998@free.fr> Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Diffstat (limited to 'package')
1 files changed, 8 insertions, 2 deletions
diff --git a/package/dropbear/S50dropbear b/package/dropbear/S50dropbear
index d94310c04e..a343b9e1c0 100644
--- a/package/dropbear/S50dropbear
+++ b/package/dropbear/S50dropbear
@@ -3,14 +3,20 @@
# Starts dropbear sshd.
+# Allow a few customizations from a config file
+test -r /etc/default/dropbear && . /etc/default/dropbear
start() {
- echo -n "Starting dropbear sshd: "
+ echo -n "Starting dropbear sshd: "
# Make sure dropbear directory exists
if [ ! -d /etc/dropbear ] ; then
mkdir -p /etc/dropbear
umask 077
- start-stop-daemon -S -q -p /var/run/dropbear.pid --exec /usr/sbin/dropbear -- -R
+ start-stop-daemon -S -q -p /var/run/dropbear.pid \
+ --exec /usr/sbin/dropbear -- $DROPBEAR_ARGS
[ $? == 0 ] && echo "OK" || echo "FAIL"
stop() {