This adds basic BPF tests for map and prog functions. The check-syntax script has been modified to exclude files listed in tools/chk_c_exclude. This is because of macros in bpf_common.c that get horribly reformatted by check-syntax. Signed-off-by: Richard Haines <richard_c_haines@xxxxxxxxxxxxxx> --- V2 Change - Split BPF code into bpf_common.c for others to use. README.md | 4 +- defconfig | 5 +++ policy/Makefile | 4 ++ policy/test_bpf.te | 77 ++++++++++++++++++++++++++++++++ tests/Makefile | 4 ++ tests/bpf/.gitignore | 2 + tests/bpf/Makefile | 12 +++++ tests/bpf/bpf_common.c | 99 ++++++++++++++++++++++++++++++++++++++++++ tests/bpf/bpf_test.c | 83 +++++++++++++++++++++++++++++++++++ tests/bpf/test | 57 ++++++++++++++++++++++++ tools/check-syntax | 2 +- tools/chk_c_exclude | 1 + 12 files changed, 348 insertions(+), 2 deletions(-) create mode 100644 policy/test_bpf.te create mode 100644 tests/bpf/.gitignore create mode 100644 tests/bpf/Makefile create mode 100644 tests/bpf/bpf_common.c create mode 100644 tests/bpf/bpf_test.c create mode 100755 tests/bpf/test create mode 100644 tools/chk_c_exclude diff --git a/README.md b/README.md index 26784f8..1396c8e 100644 --- a/README.md +++ b/README.md @@ -51,6 +51,7 @@ similar dependencies): * iptables _(to load the `iptables SECMARK` rules during `inet_socket` tests)_ * lksctp-tools-devel _(to build the SCTP test programs)_ * attr _(tools used by the overlayfs tests)_ +* libbpf-devel _(tools used by the bpf tests)_ On a modern Fedora system you can install these dependencies with the following command: @@ -65,7 +66,8 @@ following command: netlabel_tools \ iptables \ lksctp-tools-devel \ - attr + attr \ + libbpf-devel The testsuite requires a pre-existing base policy configuration of SELinux, using either the old example policy or the reference policy as the baseline. diff --git a/defconfig b/defconfig index d7f0ea5..96f6443 100644 --- a/defconfig +++ b/defconfig @@ -62,3 +62,8 @@ CONFIG_ANDROID_BINDER_IPC=y # This will configure the Dynamically Allocated Binder Devices added # to 5.0+ kernels: CONFIG_ANDROID_BINDERFS=y + +# Test BPF + check in selinux_file_receive and selinux_binder_transfer_files. +# They are not required for SELinux operation itself. +CONFIG_BP=y +CONFIG_BPF_SYSCALL=y diff --git a/policy/Makefile b/policy/Makefile index 305b572..16a4469 100644 --- a/policy/Makefile +++ b/policy/Makefile @@ -71,6 +71,10 @@ ifeq ($(shell grep -q corenet_sctp_bind_all_nodes $(POLDEV)/include/kernel/coren TARGETS += test_sctp.te endif +ifeq ($(shell grep -q bpf $(POLDEV)/include/support/all_perms.spt && echo true),true) +TARGETS += test_bpf.te +endif + ifeq (x$(DISTRO),$(filter x$(DISTRO),xRHEL4 xRHEL5 xRHEL6)) TARGETS:=$(filter-out test_overlayfs.te test_mqueue.te, $(TARGETS)) endif diff --git a/policy/test_bpf.te b/policy/test_bpf.te new file mode 100644 index 0000000..7b212e7 --- /dev/null +++ b/policy/test_bpf.te @@ -0,0 +1,77 @@ +# +################# BPF selinux-testsuite policy module ###################### +# + +attribute bpfdomain; + +################################### Main ################################### +type test_bpf_t; +domain_type(test_bpf_t) +unconfined_runs_test(test_bpf_t) +typeattribute test_bpf_t testdomain; +typeattribute test_bpf_t bpfdomain; + +allow test_bpf_t self:process setrlimit; +allow test_bpf_t self:capability { sys_resource sys_admin }; +allow test_bpf_t self:bpf { map_create map_read map_write prog_load prog_run }; + +############################## Deny map_create ############################# +type test_bpf_deny_map_create_t; +domain_type(test_bpf_deny_map_create_t) +unconfined_runs_test(test_bpf_deny_map_create_t) +typeattribute test_bpf_deny_map_create_t testdomain; +typeattribute test_bpf_deny_map_create_t bpfdomain; + +allow test_bpf_deny_map_create_t self:process setrlimit; +allow test_bpf_deny_map_create_t self:capability { sys_resource sys_admin }; +allow test_bpf_deny_map_create_t self:bpf { map_read map_write prog_load prog_run }; + +############################## Deny map_read ############################## +type test_bpf_deny_map_read_t; +domain_type(test_bpf_deny_map_read_t) +unconfined_runs_test(test_bpf_deny_map_read_t) +typeattribute test_bpf_deny_map_read_t testdomain; +typeattribute test_bpf_deny_map_read_t bpfdomain; + +allow test_bpf_deny_map_read_t self:process setrlimit; +allow test_bpf_deny_map_read_t self:capability { sys_resource sys_admin }; +allow test_bpf_deny_map_read_t self:bpf { map_create map_write prog_load prog_run }; + +############################## Deny map_write ############################## +type test_bpf_deny_map_write_t; +domain_type(test_bpf_deny_map_write_t) +unconfined_runs_test(test_bpf_deny_map_write_t) +typeattribute test_bpf_deny_map_write_t testdomain; +typeattribute test_bpf_deny_map_write_t bpfdomain; + +allow test_bpf_deny_map_write_t self:process setrlimit; +allow test_bpf_deny_map_write_t self:capability { sys_resource sys_admin }; +allow test_bpf_deny_map_write_t self:bpf { map_create map_read prog_load prog_run }; + +############################## Deny prog_load ############################## +type test_bpf_deny_prog_load_t; +domain_type(test_bpf_deny_prog_load_t) +unconfined_runs_test(test_bpf_deny_prog_load_t) +typeattribute test_bpf_deny_prog_load_t testdomain; +typeattribute test_bpf_deny_prog_load_t bpfdomain; + +allow test_bpf_deny_prog_load_t self:process setrlimit; +allow test_bpf_deny_prog_load_t self:capability { sys_resource sys_admin }; +allow test_bpf_deny_prog_load_t self:bpf { map_create map_read map_write prog_run }; + +############################## Deny prog_run ############################### +type test_bpf_deny_prog_run_t; +domain_type(test_bpf_deny_prog_run_t) +unconfined_runs_test(test_bpf_deny_prog_run_t) +typeattribute test_bpf_deny_prog_run_t testdomain; +typeattribute test_bpf_deny_prog_run_t bpfdomain; + +allow test_bpf_deny_prog_run_t self:process setrlimit; +allow test_bpf_deny_prog_run_t self:capability { sys_resource sys_admin }; +allow test_bpf_deny_prog_run_t self:bpf { map_create map_read map_write prog_load }; + +# +############ Allow these domains to be entered from sysadm domain ############ +# +miscfiles_domain_entry_test_files(bpfdomain) +userdom_sysadm_entry_spec_domtrans_to(bpfdomain) diff --git a/tests/Makefile b/tests/Makefile index 63aa325..2717452 100644 --- a/tests/Makefile +++ b/tests/Makefile @@ -42,6 +42,10 @@ ifeq ($(shell grep -q binder $(POLDEV)/include/support/all_perms.spt && test -e SUBDIRS += binder endif +ifeq ($(shell grep -q bpf $(POLDEV)/include/support/all_perms.spt && test -e $(INCLUDEDIR)/bpf/bpf.h && echo true),true) +SUBDIRS += bpf +endif + ifeq ($(shell grep "^SELINUX_INFINIBAND_ENDPORT_TEST=" infiniband_endport/ibendport_test.conf | cut -d'=' -f 2),1) SUBDIRS += infiniband_endport endif diff --git a/tests/bpf/.gitignore b/tests/bpf/.gitignore new file mode 100644 index 0000000..1919ff8 --- /dev/null +++ b/tests/bpf/.gitignore @@ -0,0 +1,2 @@ +bpf_test +bpf_common diff --git a/tests/bpf/Makefile b/tests/bpf/Makefile new file mode 100644 index 0000000..78ae9db --- /dev/null +++ b/tests/bpf/Makefile @@ -0,0 +1,12 @@ +TARGETS = bpf_test +DEPS = bpf_common.c + +LDLIBS += -lselinux -lbpf +CFLAGS += -DHAVE_BPF + +all: $(TARGETS) + +clean: + rm -f $(TARGETS) + +$(TARGETS): $(DEPS) diff --git a/tests/bpf/bpf_common.c b/tests/bpf/bpf_common.c new file mode 100644 index 0000000..c20da61 --- /dev/null +++ b/tests/bpf/bpf_common.c @@ -0,0 +1,99 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <errno.h> + +#if HAVE_BPF /* Start HAVE_BPF */ +#include <bpf/bpf.h> +#include <linux/bpf.h> +#include <sys/resource.h> + +/* edited eBPF instruction library */ +/* Short form of mov, dst_reg = imm32 */ +#define BPF_MOV64_IMM(DST, IMM) \ + ((struct bpf_insn) { \ + .code = BPF_ALU64 | BPF_MOV | BPF_K, \ + .dst_reg = DST, \ + .src_reg = 0, \ + .off = 0, \ + .imm = IMM }) + +/* Program exit */ +#define BPF_EXIT_INSN() \ + ((struct bpf_insn) { \ + .code = BPF_JMP | BPF_EXIT, \ + .dst_reg = 0, \ + .src_reg = 0, \ + .off = 0, \ + .imm = 0 }) + +int create_bpf_map(void) +{ + int map_fd, key; + long long value = 0; + + map_fd = bpf_create_map(BPF_MAP_TYPE_ARRAY, sizeof(key), + sizeof(value), 256, 0); + if (map_fd < 0) { + fprintf(stderr, "Failed to create BPF map: %s\n", + strerror(errno)); + return -1; + } + + return map_fd; +} + +int create_bpf_prog(void) +{ + int prog_fd; + size_t insns_cnt; + + struct bpf_insn prog[] = { + BPF_MOV64_IMM(BPF_REG_0, 1), + BPF_EXIT_INSN(), + }; + insns_cnt = sizeof(prog) / sizeof(struct bpf_insn); + + prog_fd = bpf_load_program(BPF_PROG_TYPE_SOCKET_FILTER, prog, + insns_cnt, "GPL", 0, NULL, 0); + if (prog_fd < 0) { + fprintf(stderr, "Failed to load BPF prog: %s\n", + strerror(errno)); + return -1; + } + + return prog_fd; +} + +void bpf_setrlimit(void) +{ + int result; + struct rlimit r = { RLIM_INFINITY, RLIM_INFINITY }; + + result = setrlimit(RLIMIT_MEMLOCK, &r); + if (result < 0) { + fprintf(stderr, "Failed to set resource limit: %s\n", + strerror(errno)); + exit(-1); + } +} + +#else +int create_bpf_map(void) +{ + fprintf(stderr, "BPF map not supported\n"); + return -1; +} + +int create_bpf_prog(void) +{ + fprintf(stderr, "BPF prog not supported\n"); + return -1; +} + +void bpf_setrlimit(void) +{ +} +#endif /* End HAVE_BPF */ diff --git a/tests/bpf/bpf_test.c b/tests/bpf/bpf_test.c new file mode 100644 index 0000000..747552c --- /dev/null +++ b/tests/bpf/bpf_test.c @@ -0,0 +1,83 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <stdio.h> +#include <unistd.h> +#include <string.h> +#include <stdlib.h> +#include <errno.h> +#include <stdbool.h> +#include <selinux/selinux.h> + +int create_bpf_map(void); +int create_bpf_prog(void); +void bpf_setrlimit(void); + +static void usage(char *progname) +{ + fprintf(stderr, + "usage: %s [-m|-p] [-v]\n" + "Where:\n\t" + "-m Create a BPF map fd\n\t" + "-p Create a BPF prog fd\n\t" + "-v Print information.\n", progname); + exit(-1); +} + +int main(int argc, char *argv[]) +{ + int opt, result, fd, bpf_fd_type = 0; + bool verbose = false; + char *context; + + while ((opt = getopt(argc, argv, "mpv")) != -1) { + switch (opt) { + case 'm': + bpf_fd_type = 1; + break; + case 'p': + bpf_fd_type = 2; + break; + case 'v': + verbose = true; + break; + default: + usage(argv[0]); + } + } + + result = getcon(&context); + if (result < 0) { + fprintf(stderr, "Failed to obtain SELinux context\n"); + exit(-1); + } + + if (verbose) + printf("Process context:\n\t%s\n", context); + + free(context); + + /* If BPF enabed, then need to set limits */ + bpf_setrlimit(); + + switch (bpf_fd_type) { + case 1: + if (verbose) + printf("Creating BPF map\n"); + + fd = create_bpf_map(); + break; + case 2: + if (verbose) + printf("Creating BPF prog\n"); + + fd = create_bpf_prog(); + break; + default: + usage(argv[0]); + } + + if (fd < 0) + return bpf_fd_type; + + return 0; +} diff --git a/tests/bpf/test b/tests/bpf/test new file mode 100755 index 0000000..0223a4c --- /dev/null +++ b/tests/bpf/test @@ -0,0 +1,57 @@ +#!/usr/bin/perl +# SPDX-License-Identifier: GPL-2.0 + +use Test::More; + +BEGIN { + $basedir = $0; + $basedir =~ s|(.*)/[^/]*|$1|; + + # allow info to be shown during tests + $v = $ARGV[0]; + if ($v) { + if ( $v ne "-v" ) { + plan skip_all => "Invalid option (use -v)"; + } + } + else { + $v = " "; + } + + plan tests => 7; +} + +# BPF map +$result = system "runcon -t test_bpf_t $basedir/bpf_test -m $v"; +ok( $result eq 0 ); + +# BPF prog +$result = system "runcon -t test_bpf_t $basedir/bpf_test -p $v"; +ok( $result eq 0 ); + +# Deny map_create permission +$result = + system "runcon -t test_bpf_deny_map_create_t $basedir/bpf_test -m $v 2>&1"; +ok( $result >> 8 eq 1 ); + +# Deny map_read permission +$result = + system "runcon -t test_bpf_deny_map_read_t $basedir/bpf_test -m $v 2>&1"; +ok( $result >> 8 eq 1 ); + +# Deny map_write permission +$result = + system "runcon -t test_bpf_deny_map_write_t $basedir/bpf_test -m $v 2>&1"; +ok( $result >> 8 eq 1 ); + +# Deny prog_load permission +$result = + system "runcon -t test_bpf_deny_prog_load_t $basedir/bpf_test -p $v 2>&1"; +ok( $result >> 8 eq 2 ); + +# Deny prog_run permission +$result = + system "runcon -t test_bpf_deny_prog_run_t $basedir/bpf_test -p $v 2>&1"; +ok( $result >> 8 eq 2 ); + +exit; diff --git a/tools/check-syntax b/tools/check-syntax index 7f9768d..5b7c211 100755 --- a/tools/check-syntax +++ b/tools/check-syntax @@ -11,7 +11,7 @@ # CHK_C_LIST="$(find tests/ -name "*.c") $(find tests/ -name "*.h")" -CHK_C_EXCLUDE="" +CHK_C_EXCLUDE="$(cat tools/chk_c_exclude)" CHK_PERL_LIST="$(find tests/ -name "*.pl") $(find tests/ -name "test")" CHK_PERL_EXCLUDE="" diff --git a/tools/chk_c_exclude b/tools/chk_c_exclude new file mode 100644 index 0000000..20facbf --- /dev/null +++ b/tools/chk_c_exclude @@ -0,0 +1 @@ +tests/bpf/bpf_common.c -- 2.21.0