From: Daniel Dickinson <open...@daniel.thecshore.com>

Failsafe mode while convenient for development and experimentation
can reasonbly considered a major security loophole (by giving an
easy way to gain passwordless root access to the device), therefore
we add the ability to build images with failsafe mode disable, either
through a compile time option, or through an image generation-time
option (passing NOFAILSAFE=1 in make command line when generating
image either through buildroot or through imagebuilder).

Signed-off-by: Daniel Dickinson <open...@daniel.thecshore.com>
---
 include/image.mk                                   |  1 +
 package/base-files/Makefile                        |  1 +
 .../files/lib/preinit/10_indicate_failsafe         |  3 +++
 .../base-files/files/lib/preinit/30_failsafe_wait  | 24 ++++++++++++++--------
 .../files/lib/preinit/40_run_failsafe_hook         |  3 +++
 package/base-files/image-config.in                 | 19 +++++++++++++----
 target/imagebuilder/files/Makefile                 |  3 ++-
 7 files changed, 41 insertions(+), 13 deletions(-)

diff --git a/include/image.mk b/include/image.mk
index 5413481..2528094 100644
--- a/include/image.mk
+++ b/include/image.mk
@@ -278,6 +278,7 @@ define Image/mkfs/prepare/default
        chmod 1777 $(TARGET_DIR)/tmp
        mkdir -p $(TARGET_DIR)/lib/preinit
        $(if $(PASSWORDLESS_CONSOLE),touch 
$(TARGET_DIR)/lib/preinit/zz_passwordless_console)
+       $(if $(NOFAILSAFE),echo 'pi_preinit_no_failsafe=y' 
>>$(TARGET_DIR)/lib/preinit/00_preinit.conf)
 endef
 
 define Image/mkfs/prepare
diff --git a/package/base-files/Makefile b/package/base-files/Makefile
index bf32f63..0b0d5af 100644
--- a/package/base-files/Makefile
+++ b/package/base-files/Makefile
@@ -80,6 +80,7 @@ define ImageConfigOptions
        echo 'pi_broadcast=$(if 
$(CONFIG_TARGET_PREINIT_BROADCAST),$(CONFIG_TARGET_PREINIT_BROADCAST),"192.168.1.255")'
 >>$(1)/lib/preinit/00_preinit.conf
        echo 'pi_preinit_net_messages="$(CONFIG_TARGET_PREINIT_SHOW_NETMSG)"' 
>>$(1)/lib/preinit/00_preinit.conf
        echo 
'pi_preinit_no_failsafe_netmsg="$(CONFIG_TARGET_PREINIT_SUPPRESS_FAILSAFE_NETMSG)"'
 >>$(1)/lib/preinit/00_preinit.conf
+       echo 
'pi_preinit_no_failsafe="$(CONFIG_TARGET_PREINIT_DISABLE_FAILSAFE)"' 
>>$(1)/lib/preinit/00_preinit.conf
 endef
 endif
 
diff --git a/package/base-files/files/lib/preinit/10_indicate_failsafe 
b/package/base-files/files/lib/preinit/10_indicate_failsafe
index 6afae41..da8ef18 100644
--- a/package/base-files/files/lib/preinit/10_indicate_failsafe
+++ b/package/base-files/files/lib/preinit/10_indicate_failsafe
@@ -9,6 +9,9 @@ indicate_failsafe_led () {
 }
 
 indicate_failsafe() {
+       if [ "$pi_preinit_no_failsafe" = "y" ]; then
+               return
+       fi
        echo "- failsafe -"
        preinit_net_echo "Entering Failsafe!\n"
        indicate_failsafe_led
diff --git a/package/base-files/files/lib/preinit/30_failsafe_wait 
b/package/base-files/files/lib/preinit/30_failsafe_wait
index 3d69baf..514bab4 100644
--- a/package/base-files/files/lib/preinit/30_failsafe_wait
+++ b/package/base-files/files/lib/preinit/30_failsafe_wait
@@ -39,7 +39,9 @@ fs_wait_for_key () {
                rm -f $keypress_wait
        } &
 
-       echo "Press the [$1] key and hit [enter] $2"
+       if [ "$pi_preinit_no_failsafe" != "y" ]; then
+               echo "Press the [$1] key and hit [enter] $2"
+       fi
        echo "Press the [1], [2], [3] or [4] key and hit [enter] to select the 
debug level"
        # if we're on the console we wait for input
        {
@@ -82,14 +84,20 @@ fs_wait_for_key () {
 
 failsafe_wait() {
        FAILSAFE=
-       grep -q 'failsafe=' /proc/cmdline && FAILSAFE=true && export FAILSAFE
+       if [ "$pi_preinit_no_failsafe" != "y" ]; then
+               grep -q 'failsafe=' /proc/cmdline && FAILSAFE=true && export 
FAILSAFE
+       fi
        if [ "$FAILSAFE" != "true" ]; then
-               pi_failsafe_net_message=true
-               preinit_net_echo "Please press button now to enter failsafe"
-               pi_failsafe_net_message=false
-               fs_wait_for_key f 'to enter failsafe mode' 
$fs_failsafe_wait_timeout && FAILSAFE=true
-               [ -f "/tmp/failsafe_button" ] && FAILSAFE=true && echo "- 
failsafe button "`cat /tmp/failsafe_button`" was pressed -"
-               [ "$FAILSAFE" = "true" ] && export FAILSAFE && touch 
/tmp/failsafe
+               if [ "$pi_preinit_no_failsafe" != "y" ]; then
+                       pi_failsafe_net_message=true
+                       preinit_net_echo "Please press button now to enter 
failsafe"
+                       pi_failsafe_net_message=false
+                       fs_wait_for_key f 'to enter failsafe mode' 
$fs_failsafe_wait_timeout && FAILSAFE=true
+                       [ -f "/tmp/failsafe_button" ] && FAILSAFE=true && echo 
"- failsafe button "`cat /tmp/failsafe_button`" was pressed -"
+                       [ "$FAILSAFE" = "true" ] && export FAILSAFE && touch 
/tmp/failsafe
+               else
+                       fs_wait_for_key "" "" $fs_failsafe_wait_timeout
+               fi
        fi
 }
 
diff --git a/package/base-files/files/lib/preinit/40_run_failsafe_hook 
b/package/base-files/files/lib/preinit/40_run_failsafe_hook
index cb43ad3..9afa33f 100644
--- a/package/base-files/files/lib/preinit/40_run_failsafe_hook
+++ b/package/base-files/files/lib/preinit/40_run_failsafe_hook
@@ -3,6 +3,9 @@
 # Copyright (C) 2010 Vertical Communications
 
 run_failsafe_hook() {
+    if [ "$pi_preinit_no_failsafe" = "y" ]; then
+       return
+    fi
     if [ "$FAILSAFE" = "true" ]; then
        boot_run_hook failsafe
        lock -w /tmp/.failsafe
diff --git a/package/base-files/image-config.in 
b/package/base-files/image-config.in
index 3dfbedc..cec9f52 100644
--- a/package/base-files/image-config.in
+++ b/package/base-files/image-config.in
@@ -24,13 +24,24 @@ config TARGET_PREINIT_SUPPRESS_STDERR
                the ash shell launched by inittab will display stderr).  That's
                the same behaviour as seen in previous version of OpenWrt.
 
+config TARGET_PREINIT_DISABLE_FAILSAFE
+       bool
+       prompt "Disable failsafe" if PREINITOPT
+       default n
+       help
+               Disable failsafe mode.  While it is very handy while
+               experimenting or developing it really ought to be
+               disabled in production environments as it is a major
+               security loophole.
+
 config TARGET_PREINIT_TIMEOUT
        int
-       prompt "Failsafe wait timeout" if PREINITOPT
+       prompt "Failsafe/Debug wait timeout" if PREINITOPT
        default 2
        help
-               How long to wait for failsafe mode to be entered before
-               continuing with a regular boot if failsafe not selected.
+               How long to wait for failsafe mode to be entered or for
+               a debug option to be pressed before continuing with a 
+               regular boot.
 
 config TARGET_PREINIT_SHOW_NETMSG
        bool
@@ -45,7 +56,7 @@ config TARGET_PREINIT_SHOW_NETMSG
 
 config TARGET_PREINIT_SUPPRESS_FAILSAFE_NETMSG
        bool
-       prompt "Suppress network message indicating failsafe" if PREINITOPT
+       prompt "Suppress network message indicating failsafe" if ( PREINITOPT 
&& !TARGET_PREINIT_SHOW_NETMSG && !TARGET_PREINIT_DISABLE_FAILSAFE )
        default n
        help
                If "Show all preinit network messages" above is not set, then
diff --git a/target/imagebuilder/files/Makefile 
b/target/imagebuilder/files/Makefile
index 64e55e2..f9838cf 100644
--- a/target/imagebuilder/files/Makefile
+++ b/target/imagebuilder/files/Makefile
@@ -44,6 +44,7 @@ Building images:
        make image FILES="<path>" # include extra files from <path>
        make image BIN_DIR="<path>" # alternative output directory for the 
images
        make image PASSWORDLESS_CONSOLE=1 # Disable requiring login prompt to 
get console shell
+       make image NOFAILSAFE=1 # Disable failsafe mode
 endef
 $(eval $(call shexport,Helptext))
 
@@ -174,7 +175,7 @@ package_postinst: FORCE
 build_image: FORCE
        @echo
        @echo Building images...
-       $(NO_TRACE_MAKE) -C target/linux/$(BOARD)/image install TARGET_BUILD=1 
IB=1 PASSWORDLESS_CONSOLE="$(PASSWORDLESS_CONSOLE)" \
+       $(NO_TRACE_MAKE) -C target/linux/$(BOARD)/image install TARGET_BUILD=1 
IB=1 PASSWORDLESS_CONSOLE="$(PASSWORDLESS_CONSOLE)" NOFAILSAFE="$(NOFAILSAFE)" \
                $(if $(USER_PROFILE),PROFILE="$(USER_PROFILE)")
 
 clean:
-- 
2.4.3
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