From: Thomas Petazzoni <thomas.petazzoni at bootlin.com> In order to support SELinux in OpenWrt, this commit introduces minimal support for loading the SELinux policy in the init code. The logic is very much inspired from what Busybox is doing: call selinux_init_load_policy() from libselinux, and then re-execute init so that it runs with the SELinux policy in place and enforced.
Signed-off-by: Thomas Petazzoni <thomas.petazzoni at bootlin.com> [fix spelling of OpenWrt] Signed-off-by: Paul Spooren <[email protected]> --- This is part of a bigger PR on GitHub[1], however this patch should be added directly to `procd` rather than as a patch in openwrt.git. As some core devs avoid GitHubs heavy frontend, I send this particular patch here again. I've tested the patch series and it compiles and runs as (I) expected. [1]: https://github.com/openwrt/openwrt/pull/3207 CMakeLists.txt | 9 ++++++++- initd/init.c | 38 ++++++++++++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+), 1 deletion(-) diff --git a/CMakeLists.txt b/CMakeLists.txt index c7adfa3..d20e57b 100644 --- a/CMakeLists.txt +++ b/CMakeLists.txt @@ -46,6 +46,12 @@ IF(ZRAM_TMPFS) SET(SOURCES_ZRAM initd/zram.c) ENDIF() +IF(SELINUX) + include(FindPkgConfig) + pkg_search_module(SELINUX REQUIRED libselinux) + add_compile_definitions(WITH_SELINUX) +ENDIF() + add_subdirectory(upgraded) ADD_EXECUTABLE(procd ${SOURCES}) @@ -62,7 +68,8 @@ ADD_DEFINITIONS(-DDISABLE_INIT) ELSE() ADD_EXECUTABLE(init initd/init.c initd/early.c initd/preinit.c initd/mkdev.c sysupgrade.c watchdog.c utils/utils.c ${SOURCES_ZRAM}) -TARGET_LINK_LIBRARIES(init ${LIBS}) +TARGET_INCLUDE_DIRECTORIES(init PUBLIC ${SELINUX_INCLUDE_DIRS}) +TARGET_LINK_LIBRARIES(init ${LIBS} ${SELINUX_LIBRARIES}) INSTALL(TARGETS init RUNTIME DESTINATION ${CMAKE_INSTALL_SBINDIR} ) diff --git a/initd/init.c b/initd/init.c index 9b47826..2eb6ead 100644 --- a/initd/init.c +++ b/initd/init.c @@ -29,6 +29,10 @@ #include <unistd.h> #include <stdio.h> +#if defined(WITH_SELINUX) +#include <selinux/selinux.h> +#endif + #include "../utils/utils.h" #include "init.h" #include "../watchdog.h" @@ -67,6 +71,38 @@ cmdline(void) } } +#if defined(WITH_SELINUX) +static int +selinux(char **argv) +{ + int enforce = 0; + int ret; + + /* SELinux already initialized */ + if (getenv("SELINUX_INIT")) + return 0; + + putenv("SELINUX_INIT=1"); + + ret = selinux_init_load_policy(&enforce); + if (ret == 0) + execv(argv[0], argv); + + if (enforce > 0) { + fprintf(stderr, "Cannot load SELinux policy, but system in enforcing mode. Halting.\n"); + return 1; + } + + return 0; +} +#else +static int +selinux(char **argv) +{ + return 0; +} +#endif + int main(int argc, char **argv) { @@ -79,6 +115,8 @@ main(int argc, char **argv) sigaction(SIGUSR2, &sa_shutdown, NULL); sigaction(SIGPWR, &sa_shutdown, NULL); + if (selinux(argv)) + exit(-1); early(); cmdline(); watchdog_init(1); -- 2.25.1 _______________________________________________ openwrt-devel mailing list [email protected] https://lists.openwrt.org/mailman/listinfo/openwrt-devel
