- Linux-kselftest-mirror - lists.linaro.org

[PATCH bpf-next v7 0/6] New BPF helpers to accelerate synproxy

by Maxim Mikityanskiy

The first patch of this series is an improvement to the existing syncookie BPF helper. The second patch is a documentation fix. The third patch allows BPF helpers to accept memory regions of fixed size without doing runtime size checks. The two last patches add new functionality that allows XDP to accelerate iptables synproxy. v1 of this series [1] used to include a patch that exposed conntrack lookup to BPF using stable helpers. It was superseded by series [2] by Kumar Kartikeya Dwivedi, which implements this functionality using unstable helpers. The fourth patch adds new helpers to issue and check SYN cookies without binding to a socket, which is useful in the synproxy scenario. The fifth patch adds a selftest, which consists of a script, an XDP program and a userspace control application. The XDP program uses socketless SYN cookie helpers and queries conntrack status instead of socket status. The userspace control application allows to tune parameters of the XDP program. This program also serves as a minimal example of usage of the new functionality. The draft of the new functionality was presented on Netdev 0x15 [3]. v2 changes: Split into two series, submitted bugfixes to bpf, dropped the conntrack patches, implemented the timestamp cookie in BPF using bpf_loop, dropped the timestamp cookie patch. v3 changes: Moved some patches from bpf to bpf-next, dropped the patch that changed error codes, split the new helpers into IPv4/IPv6, added verifier functionality to accept memory regions of fixed size. v4 changes: Converted the selftest to the test_progs runner. Replaced some deprecated functions in xdp_synproxy userspace helper. v5 changes: Fixed a bug in the selftest. Added questionable functionality to support new helpers in TC BPF, added selftests for it. v6 changes: Wrap the new helpers themselves into #ifdef CONFIG_SYN_COOKIES, replaced fclose with pclose and fixed the MSS for IPv6 in the selftest. v7 changes: Fixed the off-by-one error in indices, changed the section name to "xdp", added missing kernel config options to vmtest in CI. [1]: https://lore.kernel.org/bpf/20211020095815.GJ28644@breakpoint.cc/t/ [2]: https://lore.kernel.org/bpf/20220114163953.1455836-1-memxor@gmail.com/ [3]: https://netdevconf.info/0x15/session.html?Accelerating-synproxy-with-XDP Maxim Mikityanskiy (6): bpf: Use ipv6_only_sock in bpf_tcp_gen_syncookie bpf: Fix documentation of th_len in bpf_tcp_{gen,check}_syncookie bpf: Allow helpers to accept pointers with a fixed size bpf: Add helpers to issue and check SYN cookies in XDP bpf: Add selftests for raw syncookie helpers bpf: Allow the new syncookie helpers to work with SKBs include/linux/bpf.h | 10 + include/net/tcp.h | 1 + include/uapi/linux/bpf.h | 88 +- kernel/bpf/verifier.c | 26 +- net/core/filter.c | 130 ++- net/ipv4/tcp_input.c | 3 +- scripts/bpf_doc.py | 4 + tools/include/uapi/linux/bpf.h | 88 +- tools/testing/selftests/bpf/.gitignore | 1 + tools/testing/selftests/bpf/Makefile | 2 +- .../selftests/bpf/prog_tests/xdp_synproxy.c | 144 +++ .../selftests/bpf/progs/xdp_synproxy_kern.c | 819 ++++++++++++++++++ tools/testing/selftests/bpf/xdp_synproxy.c | 466 ++++++++++ 13 files changed, 1760 insertions(+), 22 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_synproxy.c create mode 100644 tools/testing/selftests/bpf/progs/xdp_synproxy_kern.c create mode 100644 tools/testing/selftests/bpf/xdp_synproxy.c -- 2.30.2

3 years, 6 months

1
6
0 0

[PATCH bpf-next] selftests/bpf: Fix incorrect TRUNNER_BINARY name output

by Yuntao Wang

Currently, when we run 'make test_progs', the output is: CLNG-BPF [test_maps] atomic_bounds.o ... GEN-SKEL [test_progs] atomic_bounds.skel.h ... TEST-OBJ [test_progs] align.test.o ... TEST-HDR [test_progs] tests.h EXT-OBJ [test_progs] test_progs.o ... BINARY test_progs As you can see, the TRUNNER_BINARY name in the CLNG-BPF part is test_maps, which is incorrect. Similarly, when we run 'make test_maps', the output is: CLNG-BPF [test_maps] atomic_bounds.o ... GEN-SKEL [test_progs] atomic_bounds.skel.h ... TEST-OBJ [test_maps] array_map_batch_ops.test.o ... TEST-HDR [test_maps] tests.h EXT-OBJ [test_maps] test_maps.o ... BINARY test_maps At this time, the TRUNNER_BINARY name in the GEN-SKEL part is wrong. Again, if we run 'make /full/path/to/selftests/bpf/test_vmlinux.skel.h', the output is: CLNG-BPF [test_maps] test_vmlinux.o GEN-SKEL [test_progs] test_vmlinux.skel.h Here, the TRUNNER_BINARY names are inappropriate and meaningless, they should be removed. This patch fixes these and all other similar issues. With the patch applied, the output becomes: $ make test_progs CLNG-BPF [test_progs] atomic_bounds.o ... GEN-SKEL [test_progs] atomic_bounds.skel.h ... TEST-OBJ [test_progs] align.test.o ... TEST-HDR [test_progs] tests.h EXT-OBJ [test_progs] test_progs.o ... BINARY test_progs $ make test_maps CLNG-BPF [test_maps] atomic_bounds.o ... GEN-SKEL [test_maps] atomic_bounds.skel.h ... TEST-OBJ [test_maps] array_map_batch_ops.test.o ... TEST-HDR [test_maps] tests.h EXT-OBJ [test_maps] test_maps.o ... BINARY test_maps $ make /full/path/to/selftests/bpf/test_vmlinux.skel.h CLNG-BPF test_vmlinux.o GEN-SKEL test_vmlinux.skel.h Signed-off-by: Yuntao Wang <ytcoode(a)gmail.com> --- tools/testing/selftests/bpf/Makefile | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index bafdc5373a13..3cf444cb20af 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -413,7 +413,7 @@ $(TRUNNER_BPF_OBJS): $(TRUNNER_OUTPUT)/%.o: \ $(TRUNNER_BPF_CFLAGS)) $(TRUNNER_BPF_SKELS): %.skel.h: %.o $(BPFTOOL) | $(TRUNNER_OUTPUT) - $$(call msg,GEN-SKEL,$(TRUNNER_BINARY),$$@) + $$(call msg,GEN-SKEL,$$(TRUNNER_BINARY),$$@) $(Q)$$(BPFTOOL) gen object $$(<:.o=.linked1.o) $$< $(Q)$$(BPFTOOL) gen object $$(<:.o=.linked2.o) $$(<:.o=.linked1.o) $(Q)$$(BPFTOOL) gen object $$(<:.o=.linked3.o) $$(<:.o=.linked2.o) @@ -422,7 +422,7 @@ $(TRUNNER_BPF_SKELS): %.skel.h: %.o $(BPFTOOL) | $(TRUNNER_OUTPUT) $(Q)$$(BPFTOOL) gen subskeleton $$(<:.o=.linked3.o) name $$(notdir $$(<:.o=)) > $$(@:.skel.h=.subskel.h) $(TRUNNER_BPF_LSKELS): %.lskel.h: %.o $(BPFTOOL) | $(TRUNNER_OUTPUT) - $$(call msg,GEN-SKEL,$(TRUNNER_BINARY),$$@) + $$(call msg,GEN-SKEL,$$(TRUNNER_BINARY),$$@) $(Q)$$(BPFTOOL) gen object $$(<:.o=.linked1.o) $$< $(Q)$$(BPFTOOL) gen object $$(<:.o=.linked2.o) $$(<:.o=.linked1.o) $(Q)$$(BPFTOOL) gen object $$(<:.o=.linked3.o) $$(<:.o=.linked2.o) @@ -430,12 +430,12 @@ $(TRUNNER_BPF_LSKELS): %.lskel.h: %.o $(BPFTOOL) | $(TRUNNER_OUTPUT) $(Q)$$(BPFTOOL) gen skeleton -L $$(<:.o=.linked3.o) name $$(notdir $$(<:.o=_lskel)) > $$@ $(TRUNNER_BPF_SKELS_LINKED): $(TRUNNER_BPF_OBJS) $(BPFTOOL) | $(TRUNNER_OUTPUT) - $$(call msg,LINK-BPF,$(TRUNNER_BINARY),$$(@:.skel.h=.o)) + $$(call msg,LINK-BPF,$$(TRUNNER_BINARY),$$(@:.skel.h=.o)) $(Q)$$(BPFTOOL) gen object $$(@:.skel.h=.linked1.o) $$(addprefix $(TRUNNER_OUTPUT)/,$$($$(@F)-deps)) $(Q)$$(BPFTOOL) gen object $$(@:.skel.h=.linked2.o) $$(@:.skel.h=.linked1.o) $(Q)$$(BPFTOOL) gen object $$(@:.skel.h=.linked3.o) $$(@:.skel.h=.linked2.o) $(Q)diff $$(@:.skel.h=.linked2.o) $$(@:.skel.h=.linked3.o) - $$(call msg,GEN-SKEL,$(TRUNNER_BINARY),$$@) + $$(call msg,GEN-SKEL,$$(TRUNNER_BINARY),$$@) $(Q)$$(BPFTOOL) gen skeleton $$(@:.skel.h=.linked3.o) name $$(notdir $$(@:.skel.h=)) > $$@ $(Q)$$(BPFTOOL) gen subskeleton $$(@:.skel.h=.linked3.o) name $$(notdir $$(@:.skel.h=)) > $$(@:.skel.h=.subskel.h) endif @@ -444,7 +444,7 @@ endif ifeq ($($(TRUNNER_TESTS_DIR)-tests-hdr),) $(TRUNNER_TESTS_DIR)-tests-hdr := y $(TRUNNER_TESTS_HDR): $(TRUNNER_TESTS_DIR)/*.c - $$(call msg,TEST-HDR,$(TRUNNER_BINARY),$$@) + $$(call msg,TEST-HDR,$$(TRUNNER_BINARY),$$@) $$(shell (echo '/* Generated header, do not edit */'; \ sed -n -E 's/^void (serial_)?test_([a-zA-Z0-9_]+)$(void)?$.*/DEFINE_TEST(\2)/p' \ $(TRUNNER_TESTS_DIR)/*.c | sort ; \ @@ -461,7 +461,7 @@ $(TRUNNER_TEST_OBJS): $(TRUNNER_OUTPUT)/%.test.o: \ $(TRUNNER_BPF_LSKELS) \ $(TRUNNER_BPF_SKELS_LINKED) \ $$(BPFOBJ) | $(TRUNNER_OUTPUT) - $$(call msg,TEST-OBJ,$(TRUNNER_BINARY),$$@) + $$(call msg,TEST-OBJ,$$(TRUNNER_BINARY),$$@) $(Q)cd $$(@D) && $$(CC) -I. $$(CFLAGS) -c $(CURDIR)/$$< $$(LDLIBS) -o $$(@F) $(TRUNNER_EXTRA_OBJS): $(TRUNNER_OUTPUT)/%.o: \ @@ -469,17 +469,19 @@ $(TRUNNER_EXTRA_OBJS): $(TRUNNER_OUTPUT)/%.o: \ $(TRUNNER_EXTRA_HDRS) \ $(TRUNNER_TESTS_HDR) \ $$(BPFOBJ) | $(TRUNNER_OUTPUT) - $$(call msg,EXT-OBJ,$(TRUNNER_BINARY),$$@) + $$(call msg,EXT-OBJ,$$(TRUNNER_BINARY),$$@) $(Q)$$(CC) $$(CFLAGS) -c $$< $$(LDLIBS) -o $$@ # non-flavored in-srctree builds receive special treatment, in particular, we # do not need to copy extra resources (see e.g. test_btf_dump_case()) $(TRUNNER_BINARY)-extras: $(TRUNNER_EXTRA_FILES) | $(TRUNNER_OUTPUT) ifneq ($2:$(OUTPUT),:$(shell pwd)) - $$(call msg,EXT-COPY,$(TRUNNER_BINARY),$(TRUNNER_EXTRA_FILES)) + $$(call msg,EXT-COPY,$$(TRUNNER_BINARY),$(TRUNNER_EXTRA_FILES)) $(Q)rsync -aq $$^ $(TRUNNER_OUTPUT)/ endif +$(OUTPUT)/$(TRUNNER_BINARY): TRUNNER_BINARY = $(TRUNNER_BINARY) + $(OUTPUT)/$(TRUNNER_BINARY): $(TRUNNER_TEST_OBJS) \ $(TRUNNER_EXTRA_OBJS) $$(BPFOBJ) \ $(RESOLVE_BTFIDS) \ @@ -489,6 +491,8 @@ $(OUTPUT)/$(TRUNNER_BINARY): $(TRUNNER_TEST_OBJS) \ $(Q)$(RESOLVE_BTFIDS) --btf $(TRUNNER_OUTPUT)/btf_data.o $$@ $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/bootstrap/bpftool $(if $2,$2/)bpftool +TRUNNER_BINARY = + endef # Define test_progs test runner. -- 2.35.3

3 years, 6 months

2
2
0 0

Koszty instalacji fotowoltaicznej

by "Arkadiusz Sokołowski"

Dzień dobry, stworzyliśmy specjalną ofertę dla firm, na kompleksową obsługę inwestycji w fotowoltaikę. Specjalizujemy się w zakresie doboru, montażu i serwisie instalacji fotowoltaicznych, dysponujemy najnowocześniejszymi rozwiązania, które zapewnią Państwu oczekiwane rezultaty. Możemy przygotować dla Państwa wstępną kalkulację i przeanalizować efekty możliwe do osiągnięcia. Czy są Państwo otwarci na wstępną rozmowę w tym temacie? Pozdrawiam Arkadiusz Sokołowski

3 years, 6 months

1
0
0 0

[PATCH bpf-next v6 0/5] New BPF helpers to accelerate synproxy

by Maxim Mikityanskiy

The first patch of this series is an improvement to the existing syncookie BPF helper. The second patch is a documentation fix. The third patch allows BPF helpers to accept memory regions of fixed size without doing runtime size checks. The two last patches add new functionality that allows XDP to accelerate iptables synproxy. v1 of this series [1] used to include a patch that exposed conntrack lookup to BPF using stable helpers. It was superseded by series [2] by Kumar Kartikeya Dwivedi, which implements this functionality using unstable helpers. The fourth patch adds new helpers to issue and check SYN cookies without binding to a socket, which is useful in the synproxy scenario. The fifth patch adds a selftest, which consists of a script, an XDP program and a userspace control application. The XDP program uses socketless SYN cookie helpers and queries conntrack status instead of socket status. The userspace control application allows to tune parameters of the XDP program. This program also serves as a minimal example of usage of the new functionality. The draft of the new functionality was presented on Netdev 0x15 [3]. v2 changes: Split into two series, submitted bugfixes to bpf, dropped the conntrack patches, implemented the timestamp cookie in BPF using bpf_loop, dropped the timestamp cookie patch. v3 changes: Moved some patches from bpf to bpf-next, dropped the patch that changed error codes, split the new helpers into IPv4/IPv6, added verifier functionality to accept memory regions of fixed size. v4 changes: Converted the selftest to the test_progs runner. Replaced some deprecated functions in xdp_synproxy userspace helper. v5 changes: Fixed a bug in the selftest. Added questionable functionality to support new helpers in TC BPF, added selftests for it. v6 changes: Wrap the new helpers themselves into #ifdef CONFIG_SYN_COOKIES, replaced fclose with pclose and fixed the MSS for IPv6 in the selftest. [1]: https://lore.kernel.org/bpf/20211020095815.GJ28644@breakpoint.cc/t/ [2]: https://lore.kernel.org/bpf/20220114163953.1455836-1-memxor@gmail.com/ [3]: https://netdevconf.info/0x15/session.html?Accelerating-synproxy-with-XDP Maxim Mikityanskiy (6): bpf: Use ipv6_only_sock in bpf_tcp_gen_syncookie bpf: Fix documentation of th_len in bpf_tcp_{gen,check}_syncookie bpf: Allow helpers to accept pointers with a fixed size bpf: Add helpers to issue and check SYN cookies in XDP bpf: Add selftests for raw syncookie helpers bpf: Allow the new syncookie helpers to work with SKBs include/linux/bpf.h | 10 + include/net/tcp.h | 1 + include/uapi/linux/bpf.h | 88 +- kernel/bpf/verifier.c | 26 +- net/core/filter.c | 130 ++- net/ipv4/tcp_input.c | 3 +- scripts/bpf_doc.py | 4 + tools/include/uapi/linux/bpf.h | 88 +- tools/testing/selftests/bpf/.gitignore | 1 + tools/testing/selftests/bpf/Makefile | 2 +- .../selftests/bpf/prog_tests/xdp_synproxy.c | 144 +++ .../selftests/bpf/progs/xdp_synproxy_kern.c | 819 ++++++++++++++++++ tools/testing/selftests/bpf/xdp_synproxy.c | 466 ++++++++++ 13 files changed, 1760 insertions(+), 22 deletions(-) create mode 100644 tools/testing/selftests/bpf/prog_tests/xdp_synproxy.c create mode 100644 tools/testing/selftests/bpf/progs/xdp_synproxy_kern.c create mode 100644 tools/testing/selftests/bpf/xdp_synproxy.c -- 2.30.2

3 years, 6 months

4
14
0 0

[PATCH] kselftest/arm64: fix array_size.cocci warning

by Guo Zhengkui

Fix the following coccicheck warnings: tools/testing/selftests/arm64/mte/check_child_memory.c:110:25-26: WARNING: Use ARRAY_SIZE tools/testing/selftests/arm64/mte/check_child_memory.c:88:24-25: WARNING: Use ARRAY_SIZE tools/testing/selftests/arm64/mte/check_child_memory.c:90:20-21: WARNING: Use ARRAY_SIZE tools/testing/selftests/arm64/mte/check_child_memory.c:147:24-25: WARNING: Use ARRAY_SIZE `ARRAY_SIZE` macro is defined in tools/testing/selftests/kselftest.h. Signed-off-by: Guo Zhengkui <guozhengkui(a)vivo.com> --- tools/testing/selftests/arm64/mte/check_child_memory.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/arm64/mte/check_child_memory.c b/tools/testing/selftests/arm64/mte/check_child_memory.c index 43bd94f853ba..7597fc632cad 100644 --- a/tools/testing/selftests/arm64/mte/check_child_memory.c +++ b/tools/testing/selftests/arm64/mte/check_child_memory.c @@ -85,9 +85,9 @@ static int check_child_memory_mapping(int mem_type, int mode, int mapping) { char *ptr; int run, result; - int item = sizeof(sizes)/sizeof(int); + int item = ARRAY_SIZE(sizes); - item = sizeof(sizes)/sizeof(int); + item = ARRAY_SIZE(sizes); mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG); for (run = 0; run < item; run++) { ptr = (char *)mte_allocate_memory_tag_range(sizes[run], mem_type, mapping, @@ -107,7 +107,7 @@ static int check_child_file_mapping(int mem_type, int mode, int mapping) { char *ptr, *map_ptr; int run, fd, map_size, result = KSFT_PASS; - int total = sizeof(sizes)/sizeof(int); + int total = ARRAY_SIZE(sizes); mte_switch_mode(mode, MTE_ALLOW_NON_ZERO_TAG); for (run = 0; run < total; run++) { @@ -144,7 +144,7 @@ static int check_child_file_mapping(int mem_type, int mode, int mapping) int main(int argc, char *argv[]) { int err; - int item = sizeof(sizes)/sizeof(int); + int item = ARRAY_SIZE(sizes); page_size = getpagesize(); if (!page_size) { -- 2.20.1

3 years, 6 months

3
2
0 0

[PATCH v2 0/4] selftests/arm64: Fix O= builds for the FP selftests

by Mark Brown

Currently the arm64 selftests don't support building with O=, this series fixes that, bringing them more into line with how the kselftest Makefiles want to work. v2: - Rebase onto v5.18-rc3. Mark Brown (4): selftests/arm64: Use TEST_GEN_PROGS_EXTENDED in the FP Makefile selftests/arm64: Define top_srcdir for the fp tests selftests/arm64: Clean the fp helper libraries selftests/arm64: Fix O= builds for the floating point tests tools/testing/selftests/arm64/fp/Makefile | 29 +++++++++++++---------- 1 file changed, 17 insertions(+), 12 deletions(-) base-commit: b2d229d4ddb17db541098b83524d901257e93845 -- 2.30.2

3 years, 6 months

2
8
0 0

[PATCH MANUALSEL 5.15 1/7] kvm: selftests: do not use bitfields larger than 32-bits for PTEs

by Sasha Levin

From: Paolo Bonzini <pbonzini(a)redhat.com> [ Upstream commit f18b4aebe107d092e384b1ae680b1e1de7a0196d ] Red Hat's QE team reported test failure on access_tracking_perf_test: Testing guest mode: PA-bits:ANY, VA-bits:48, 4K pages guest physical test memory offset: 0x3fffbffff000 Populating memory : 0.684014577s Writing to populated memory : 0.006230175s Reading from populated memory : 0.004557805s ==== Test Assertion Failure ==== lib/kvm_util.c:1411: false pid=125806 tid=125809 errno=4 - Interrupted system call 1 0x0000000000402f7c: addr_gpa2hva at kvm_util.c:1411 2 (inlined by) addr_gpa2hva at kvm_util.c:1405 3 0x0000000000401f52: lookup_pfn at access_tracking_perf_test.c:98 4 (inlined by) mark_vcpu_memory_idle at access_tracking_perf_test.c:152 5 (inlined by) vcpu_thread_main at access_tracking_perf_test.c:232 6 0x00007fefe9ff81ce: ?? ??:0 7 0x00007fefe9c64d82: ?? ??:0 No vm physical memory at 0xffbffff000 I can easily reproduce it with a Intel(R) Xeon(R) CPU E5-2630 with 46 bits PA. It turns out that the address translation for clearing idle page tracking returned a wrong result; addr_gva2gpa()'s last step, which is based on "pte[index[0]].pfn", did the calculation with 40 bits length and the high 12 bits got truncated. In above case the GPA address to be returned should be 0x3fffbffff000 for GVA 0xc0000000, but it got truncated into 0xffbffff000 and the subsequent gpa2hva lookup failed. The width of operations on bit fields greater than 32-bit is implementation defined, and differs between GCC (which uses the bitfield precision) and clang (which uses 64-bit arithmetic), so this is a potential minefield. Remove the bit fields and using manual masking instead. Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2075036 Reported-by: Nana Liu <nanliu(a)redhat.com> Reviewed-by: Peter Xu <peterx(a)redhat.com> Tested-by: Peter Xu <peterx(a)redhat.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- .../selftests/kvm/include/x86_64/processor.h | 15 ++ .../selftests/kvm/lib/x86_64/processor.c | 192 +++++++----------- 2 files changed, 92 insertions(+), 115 deletions(-) diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index 05e65ca1c30c..23861c8faa61 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -58,6 +58,21 @@ /* CPUID.0x8000_0001.EDX */ #define CPUID_GBPAGES (1ul << 26) +/* Page table bitfield declarations */ +#define PTE_PRESENT_MASK BIT_ULL(0) +#define PTE_WRITABLE_MASK BIT_ULL(1) +#define PTE_USER_MASK BIT_ULL(2) +#define PTE_ACCESSED_MASK BIT_ULL(5) +#define PTE_DIRTY_MASK BIT_ULL(6) +#define PTE_LARGE_MASK BIT_ULL(7) +#define PTE_GLOBAL_MASK BIT_ULL(8) +#define PTE_NX_MASK BIT_ULL(63) + +#define PAGE_SHIFT 12 + +#define PHYSICAL_PAGE_MASK GENMASK_ULL(51, 12) +#define PTE_GET_PFN(pte) (((pte) & PHYSICAL_PAGE_MASK) >> PAGE_SHIFT) + /* General Registers in 64-Bit Mode */ struct gpr64_regs { u64 rax; diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index da73b97e1e6d..46057079d8bb 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -19,38 +19,6 @@ vm_vaddr_t exception_handlers; -/* Virtual translation table structure declarations */ -struct pageUpperEntry { - uint64_t present:1; - uint64_t writable:1; - uint64_t user:1; - uint64_t write_through:1; - uint64_t cache_disable:1; - uint64_t accessed:1; - uint64_t ignored_06:1; - uint64_t page_size:1; - uint64_t ignored_11_08:4; - uint64_t pfn:40; - uint64_t ignored_62_52:11; - uint64_t execute_disable:1; -}; - -struct pageTableEntry { - uint64_t present:1; - uint64_t writable:1; - uint64_t user:1; - uint64_t write_through:1; - uint64_t cache_disable:1; - uint64_t accessed:1; - uint64_t dirty:1; - uint64_t reserved_07:1; - uint64_t global:1; - uint64_t ignored_11_09:3; - uint64_t pfn:40; - uint64_t ignored_62_52:11; - uint64_t execute_disable:1; -}; - void regs_dump(FILE *stream, struct kvm_regs *regs, uint8_t indent) { @@ -195,23 +163,21 @@ static void *virt_get_pte(struct kvm_vm *vm, uint64_t pt_pfn, uint64_t vaddr, return &page_table[index]; } -static struct pageUpperEntry *virt_create_upper_pte(struct kvm_vm *vm, - uint64_t pt_pfn, - uint64_t vaddr, - uint64_t paddr, - int level, - enum x86_page_size page_size) +static uint64_t *virt_create_upper_pte(struct kvm_vm *vm, + uint64_t pt_pfn, + uint64_t vaddr, + uint64_t paddr, + int level, + enum x86_page_size page_size) { - struct pageUpperEntry *pte = virt_get_pte(vm, pt_pfn, vaddr, level); - - if (!pte->present) { - pte->writable = true; - pte->present = true; - pte->page_size = (level == page_size); - if (pte->page_size) - pte->pfn = paddr >> vm->page_shift; + uint64_t *pte = virt_get_pte(vm, pt_pfn, vaddr, level); + + if (!(*pte & PTE_PRESENT_MASK)) { + *pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK; + if (level == page_size) + *pte |= PTE_LARGE_MASK | (paddr & PHYSICAL_PAGE_MASK); else - pte->pfn = vm_alloc_page_table(vm) >> vm->page_shift; + *pte |= vm_alloc_page_table(vm) & PHYSICAL_PAGE_MASK; } else { /* * Entry already present. Assert that the caller doesn't want @@ -221,7 +187,7 @@ static struct pageUpperEntry *virt_create_upper_pte(struct kvm_vm *vm, TEST_ASSERT(level != page_size, "Cannot create hugepage at level: %u, vaddr: 0x%lx\n", page_size, vaddr); - TEST_ASSERT(!pte->page_size, + TEST_ASSERT(!(*pte & PTE_LARGE_MASK), "Cannot create page table at level: %u, vaddr: 0x%lx\n", level, vaddr); } @@ -232,8 +198,8 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, enum x86_page_size page_size) { const uint64_t pg_size = 1ull << ((page_size * 9) + 12); - struct pageUpperEntry *pml4e, *pdpe, *pde; - struct pageTableEntry *pte; + uint64_t *pml4e, *pdpe, *pde; + uint64_t *pte; TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Unknown or unsupported guest mode, mode: 0x%x", vm->mode); @@ -257,24 +223,22 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, */ pml4e = virt_create_upper_pte(vm, vm->pgd >> vm->page_shift, vaddr, paddr, 3, page_size); - if (pml4e->page_size) + if (*pml4e & PTE_LARGE_MASK) return; - pdpe = virt_create_upper_pte(vm, pml4e->pfn, vaddr, paddr, 2, page_size); - if (pdpe->page_size) + pdpe = virt_create_upper_pte(vm, PTE_GET_PFN(*pml4e), vaddr, paddr, 2, page_size); + if (*pdpe & PTE_LARGE_MASK) return; - pde = virt_create_upper_pte(vm, pdpe->pfn, vaddr, paddr, 1, page_size); - if (pde->page_size) + pde = virt_create_upper_pte(vm, PTE_GET_PFN(*pdpe), vaddr, paddr, 1, page_size); + if (*pde & PTE_LARGE_MASK) return; /* Fill in page table entry. */ - pte = virt_get_pte(vm, pde->pfn, vaddr, 0); - TEST_ASSERT(!pte->present, + pte = virt_get_pte(vm, PTE_GET_PFN(*pde), vaddr, 0); + TEST_ASSERT(!(*pte & PTE_PRESENT_MASK), "PTE already present for 4k page at vaddr: 0x%lx\n", vaddr); - pte->pfn = paddr >> vm->page_shift; - pte->writable = true; - pte->present = 1; + *pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK | (paddr & PHYSICAL_PAGE_MASK); } void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr) @@ -282,12 +246,12 @@ void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr) __virt_pg_map(vm, vaddr, paddr, X86_PAGE_SIZE_4K); } -static struct pageTableEntry *_vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid, +static uint64_t *_vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr) { uint16_t index[4]; - struct pageUpperEntry *pml4e, *pdpe, *pde; - struct pageTableEntry *pte; + uint64_t *pml4e, *pdpe, *pde; + uint64_t *pte; struct kvm_cpuid_entry2 *entry; struct kvm_sregs sregs; int max_phy_addr; @@ -329,30 +293,29 @@ static struct pageTableEntry *_vm_get_page_table_entry(struct kvm_vm *vm, int vc index[3] = (vaddr >> 39) & 0x1ffu; pml4e = addr_gpa2hva(vm, vm->pgd); - TEST_ASSERT(pml4e[index[3]].present, + TEST_ASSERT(pml4e[index[3]] & PTE_PRESENT_MASK, "Expected pml4e to be present for gva: 0x%08lx", vaddr); - TEST_ASSERT((*(uint64_t*)(&pml4e[index[3]]) & - (rsvd_mask | (1ull << 7))) == 0, + TEST_ASSERT((pml4e[index[3]] & (rsvd_mask | PTE_LARGE_MASK)) == 0, "Unexpected reserved bits set."); - pdpe = addr_gpa2hva(vm, pml4e[index[3]].pfn * vm->page_size); - TEST_ASSERT(pdpe[index[2]].present, + pdpe = addr_gpa2hva(vm, PTE_GET_PFN(pml4e[index[3]]) * vm->page_size); + TEST_ASSERT(pdpe[index[2]] & PTE_PRESENT_MASK, "Expected pdpe to be present for gva: 0x%08lx", vaddr); - TEST_ASSERT(pdpe[index[2]].page_size == 0, + TEST_ASSERT(!(pdpe[index[2]] & PTE_LARGE_MASK), "Expected pdpe to map a pde not a 1-GByte page."); - TEST_ASSERT((*(uint64_t*)(&pdpe[index[2]]) & rsvd_mask) == 0, + TEST_ASSERT((pdpe[index[2]] & rsvd_mask) == 0, "Unexpected reserved bits set."); - pde = addr_gpa2hva(vm, pdpe[index[2]].pfn * vm->page_size); - TEST_ASSERT(pde[index[1]].present, + pde = addr_gpa2hva(vm, PTE_GET_PFN(pdpe[index[2]]) * vm->page_size); + TEST_ASSERT(pde[index[1]] & PTE_PRESENT_MASK, "Expected pde to be present for gva: 0x%08lx", vaddr); - TEST_ASSERT(pde[index[1]].page_size == 0, + TEST_ASSERT(!(pde[index[1]] & PTE_LARGE_MASK), "Expected pde to map a pte not a 2-MByte page."); - TEST_ASSERT((*(uint64_t*)(&pde[index[1]]) & rsvd_mask) == 0, + TEST_ASSERT((pde[index[1]] & rsvd_mask) == 0, "Unexpected reserved bits set."); - pte = addr_gpa2hva(vm, pde[index[1]].pfn * vm->page_size); - TEST_ASSERT(pte[index[0]].present, + pte = addr_gpa2hva(vm, PTE_GET_PFN(pde[index[1]]) * vm->page_size); + TEST_ASSERT(pte[index[0]] & PTE_PRESENT_MASK, "Expected pte to be present for gva: 0x%08lx", vaddr); return &pte[index[0]]; @@ -360,7 +323,7 @@ static struct pageTableEntry *_vm_get_page_table_entry(struct kvm_vm *vm, int vc uint64_t vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr) { - struct pageTableEntry *pte = _vm_get_page_table_entry(vm, vcpuid, vaddr); + uint64_t *pte = _vm_get_page_table_entry(vm, vcpuid, vaddr); return *(uint64_t *)pte; } @@ -368,18 +331,17 @@ uint64_t vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr) void vm_set_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr, uint64_t pte) { - struct pageTableEntry *new_pte = _vm_get_page_table_entry(vm, vcpuid, - vaddr); + uint64_t *new_pte = _vm_get_page_table_entry(vm, vcpuid, vaddr); *(uint64_t *)new_pte = pte; } void virt_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent) { - struct pageUpperEntry *pml4e, *pml4e_start; - struct pageUpperEntry *pdpe, *pdpe_start; - struct pageUpperEntry *pde, *pde_start; - struct pageTableEntry *pte, *pte_start; + uint64_t *pml4e, *pml4e_start; + uint64_t *pdpe, *pdpe_start; + uint64_t *pde, *pde_start; + uint64_t *pte, *pte_start; if (!vm->pgd_created) return; @@ -389,58 +351,58 @@ void virt_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent) fprintf(stream, "%*s index hvaddr gpaddr " "addr w exec dirty\n", indent, ""); - pml4e_start = (struct pageUpperEntry *) addr_gpa2hva(vm, vm->pgd); + pml4e_start = (uint64_t *) addr_gpa2hva(vm, vm->pgd); for (uint16_t n1 = 0; n1 <= 0x1ffu; n1++) { pml4e = &pml4e_start[n1]; - if (!pml4e->present) + if (!(*pml4e & PTE_PRESENT_MASK)) continue; - fprintf(stream, "%*spml4e 0x%-3zx %p 0x%-12lx 0x%-10lx %u " + fprintf(stream, "%*spml4e 0x%-3zx %p 0x%-12lx 0x%-10llx %u " " %u\n", indent, "", pml4e - pml4e_start, pml4e, - addr_hva2gpa(vm, pml4e), (uint64_t) pml4e->pfn, - pml4e->writable, pml4e->execute_disable); + addr_hva2gpa(vm, pml4e), PTE_GET_PFN(*pml4e), + !!(*pml4e & PTE_WRITABLE_MASK), !!(*pml4e & PTE_NX_MASK)); - pdpe_start = addr_gpa2hva(vm, pml4e->pfn * vm->page_size); + pdpe_start = addr_gpa2hva(vm, *pml4e & PHYSICAL_PAGE_MASK); for (uint16_t n2 = 0; n2 <= 0x1ffu; n2++) { pdpe = &pdpe_start[n2]; - if (!pdpe->present) + if (!(*pdpe & PTE_PRESENT_MASK)) continue; - fprintf(stream, "%*spdpe 0x%-3zx %p 0x%-12lx 0x%-10lx " + fprintf(stream, "%*spdpe 0x%-3zx %p 0x%-12lx 0x%-10llx " "%u %u\n", indent, "", pdpe - pdpe_start, pdpe, addr_hva2gpa(vm, pdpe), - (uint64_t) pdpe->pfn, pdpe->writable, - pdpe->execute_disable); + PTE_GET_PFN(*pdpe), !!(*pdpe & PTE_WRITABLE_MASK), + !!(*pdpe & PTE_NX_MASK)); - pde_start = addr_gpa2hva(vm, pdpe->pfn * vm->page_size); + pde_start = addr_gpa2hva(vm, *pdpe & PHYSICAL_PAGE_MASK); for (uint16_t n3 = 0; n3 <= 0x1ffu; n3++) { pde = &pde_start[n3]; - if (!pde->present) + if (!(*pde & PTE_PRESENT_MASK)) continue; fprintf(stream, "%*spde 0x%-3zx %p " - "0x%-12lx 0x%-10lx %u %u\n", + "0x%-12lx 0x%-10llx %u %u\n", indent, "", pde - pde_start, pde, addr_hva2gpa(vm, pde), - (uint64_t) pde->pfn, pde->writable, - pde->execute_disable); + PTE_GET_PFN(*pde), !!(*pde & PTE_WRITABLE_MASK), + !!(*pde & PTE_NX_MASK)); - pte_start = addr_gpa2hva(vm, pde->pfn * vm->page_size); + pte_start = addr_gpa2hva(vm, *pde & PHYSICAL_PAGE_MASK); for (uint16_t n4 = 0; n4 <= 0x1ffu; n4++) { pte = &pte_start[n4]; - if (!pte->present) + if (!(*pte & PTE_PRESENT_MASK)) continue; fprintf(stream, "%*spte 0x%-3zx %p " - "0x%-12lx 0x%-10lx %u %u " + "0x%-12lx 0x%-10llx %u %u " " %u 0x%-10lx\n", indent, "", pte - pte_start, pte, addr_hva2gpa(vm, pte), - (uint64_t) pte->pfn, - pte->writable, - pte->execute_disable, - pte->dirty, + PTE_GET_PFN(*pte), + !!(*pte & PTE_WRITABLE_MASK), + !!(*pte & PTE_NX_MASK), + !!(*pte & PTE_DIRTY_MASK), ((uint64_t) n1 << 27) | ((uint64_t) n2 << 18) | ((uint64_t) n3 << 9) @@ -558,8 +520,8 @@ static void kvm_seg_set_kernel_data_64bit(struct kvm_vm *vm, uint16_t selector, vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva) { uint16_t index[4]; - struct pageUpperEntry *pml4e, *pdpe, *pde; - struct pageTableEntry *pte; + uint64_t *pml4e, *pdpe, *pde; + uint64_t *pte; TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Attempt to use " "unknown or unsupported guest mode, mode: 0x%x", vm->mode); @@ -572,22 +534,22 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva) if (!vm->pgd_created) goto unmapped_gva; pml4e = addr_gpa2hva(vm, vm->pgd); - if (!pml4e[index[3]].present) + if (!(pml4e[index[3]] & PTE_PRESENT_MASK)) goto unmapped_gva; - pdpe = addr_gpa2hva(vm, pml4e[index[3]].pfn * vm->page_size); - if (!pdpe[index[2]].present) + pdpe = addr_gpa2hva(vm, PTE_GET_PFN(pml4e[index[3]]) * vm->page_size); + if (!(pdpe[index[2]] & PTE_PRESENT_MASK)) goto unmapped_gva; - pde = addr_gpa2hva(vm, pdpe[index[2]].pfn * vm->page_size); - if (!pde[index[1]].present) + pde = addr_gpa2hva(vm, PTE_GET_PFN(pdpe[index[2]]) * vm->page_size); + if (!(pde[index[1]] & PTE_PRESENT_MASK)) goto unmapped_gva; - pte = addr_gpa2hva(vm, pde[index[1]].pfn * vm->page_size); - if (!pte[index[0]].present) + pte = addr_gpa2hva(vm, PTE_GET_PFN(pde[index[1]]) * vm->page_size); + if (!(pte[index[0]] & PTE_PRESENT_MASK)) goto unmapped_gva; - return (pte[index[0]].pfn * vm->page_size) + (gva & 0xfffu); + return (PTE_GET_PFN(pte[index[0]]) * vm->page_size) + (gva & 0xfffu); unmapped_gva: TEST_FAIL("No mapping for vm virtual address, gva: 0x%lx", gva); -- 2.35.1

3 years, 6 months

2
3
0 0

[PATCH] selftests: cgroup: Fix unsigned expression compared with zero

by Jiapeng Chong

Fix the following coccicheck warnings: ./tools/testing/selftests/cgroup/cgroup_util.c:566:8-12: WARNING: Unsigned expression compared with zero: size < 0. Reported-by: Abaci Robot <abaci(a)linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong(a)linux.alibaba.com> --- tools/testing/selftests/cgroup/cgroup_util.c | 2 +- tools/testing/selftests/cgroup/cgroup_util.h | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/cgroup/cgroup_util.c b/tools/testing/selftests/cgroup/cgroup_util.c index 4c52cc6f2f9c..661e06b94a43 100644 --- a/tools/testing/selftests/cgroup/cgroup_util.c +++ b/tools/testing/selftests/cgroup/cgroup_util.c @@ -552,7 +552,7 @@ int proc_mount_contains(const char *option) return strstr(buf, option) != NULL; } -ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t size) +ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, ssize_t size) { char path[PATH_MAX]; diff --git a/tools/testing/selftests/cgroup/cgroup_util.h b/tools/testing/selftests/cgroup/cgroup_util.h index c92df4e5d395..7b3865805f50 100644 --- a/tools/testing/selftests/cgroup/cgroup_util.h +++ b/tools/testing/selftests/cgroup/cgroup_util.h @@ -53,7 +53,7 @@ extern int set_oom_adj_score(int pid, int score); extern int cg_wait_for_proc_count(const char *cgroup, int count); extern int cg_killall(const char *cgroup); int proc_mount_contains(const char *option); -extern ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, size_t size); +extern ssize_t proc_read_text(int pid, bool thread, const char *item, char *buf, ssize_t size); extern int proc_read_strstr(int pid, bool thread, const char *item, const char *needle); extern pid_t clone_into_cgroup(int cgroup_fd); extern int clone_reap(pid_t pid, int options); -- 2.20.1.7.g153144c

3 years, 6 months

2
1
0 0

[PATCH MANUALSEL 5.17 1/7] kvm: selftests: do not use bitfields larger than 32-bits for PTEs

by Sasha Levin

From: Paolo Bonzini <pbonzini(a)redhat.com> [ Upstream commit f18b4aebe107d092e384b1ae680b1e1de7a0196d ] Red Hat's QE team reported test failure on access_tracking_perf_test: Testing guest mode: PA-bits:ANY, VA-bits:48, 4K pages guest physical test memory offset: 0x3fffbffff000 Populating memory : 0.684014577s Writing to populated memory : 0.006230175s Reading from populated memory : 0.004557805s ==== Test Assertion Failure ==== lib/kvm_util.c:1411: false pid=125806 tid=125809 errno=4 - Interrupted system call 1 0x0000000000402f7c: addr_gpa2hva at kvm_util.c:1411 2 (inlined by) addr_gpa2hva at kvm_util.c:1405 3 0x0000000000401f52: lookup_pfn at access_tracking_perf_test.c:98 4 (inlined by) mark_vcpu_memory_idle at access_tracking_perf_test.c:152 5 (inlined by) vcpu_thread_main at access_tracking_perf_test.c:232 6 0x00007fefe9ff81ce: ?? ??:0 7 0x00007fefe9c64d82: ?? ??:0 No vm physical memory at 0xffbffff000 I can easily reproduce it with a Intel(R) Xeon(R) CPU E5-2630 with 46 bits PA. It turns out that the address translation for clearing idle page tracking returned a wrong result; addr_gva2gpa()'s last step, which is based on "pte[index[0]].pfn", did the calculation with 40 bits length and the high 12 bits got truncated. In above case the GPA address to be returned should be 0x3fffbffff000 for GVA 0xc0000000, but it got truncated into 0xffbffff000 and the subsequent gpa2hva lookup failed. The width of operations on bit fields greater than 32-bit is implementation defined, and differs between GCC (which uses the bitfield precision) and clang (which uses 64-bit arithmetic), so this is a potential minefield. Remove the bit fields and using manual masking instead. Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2075036 Reported-by: Nana Liu <nanliu(a)redhat.com> Reviewed-by: Peter Xu <peterx(a)redhat.com> Tested-by: Peter Xu <peterx(a)redhat.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- .../selftests/kvm/include/x86_64/processor.h | 15 ++ .../selftests/kvm/lib/x86_64/processor.c | 192 +++++++----------- 2 files changed, 92 insertions(+), 115 deletions(-) diff --git a/tools/testing/selftests/kvm/include/x86_64/processor.h b/tools/testing/selftests/kvm/include/x86_64/processor.h index 8a470da7b71a..15a2875698b5 100644 --- a/tools/testing/selftests/kvm/include/x86_64/processor.h +++ b/tools/testing/selftests/kvm/include/x86_64/processor.h @@ -60,6 +60,21 @@ /* CPUID.0x8000_0001.EDX */ #define CPUID_GBPAGES (1ul << 26) +/* Page table bitfield declarations */ +#define PTE_PRESENT_MASK BIT_ULL(0) +#define PTE_WRITABLE_MASK BIT_ULL(1) +#define PTE_USER_MASK BIT_ULL(2) +#define PTE_ACCESSED_MASK BIT_ULL(5) +#define PTE_DIRTY_MASK BIT_ULL(6) +#define PTE_LARGE_MASK BIT_ULL(7) +#define PTE_GLOBAL_MASK BIT_ULL(8) +#define PTE_NX_MASK BIT_ULL(63) + +#define PAGE_SHIFT 12 + +#define PHYSICAL_PAGE_MASK GENMASK_ULL(51, 12) +#define PTE_GET_PFN(pte) (((pte) & PHYSICAL_PAGE_MASK) >> PAGE_SHIFT) + /* General Registers in 64-Bit Mode */ struct gpr64_regs { u64 rax; diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index 9f000dfb5594..0dd442c26015 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -19,38 +19,6 @@ vm_vaddr_t exception_handlers; -/* Virtual translation table structure declarations */ -struct pageUpperEntry { - uint64_t present:1; - uint64_t writable:1; - uint64_t user:1; - uint64_t write_through:1; - uint64_t cache_disable:1; - uint64_t accessed:1; - uint64_t ignored_06:1; - uint64_t page_size:1; - uint64_t ignored_11_08:4; - uint64_t pfn:40; - uint64_t ignored_62_52:11; - uint64_t execute_disable:1; -}; - -struct pageTableEntry { - uint64_t present:1; - uint64_t writable:1; - uint64_t user:1; - uint64_t write_through:1; - uint64_t cache_disable:1; - uint64_t accessed:1; - uint64_t dirty:1; - uint64_t reserved_07:1; - uint64_t global:1; - uint64_t ignored_11_09:3; - uint64_t pfn:40; - uint64_t ignored_62_52:11; - uint64_t execute_disable:1; -}; - void regs_dump(FILE *stream, struct kvm_regs *regs, uint8_t indent) { @@ -195,23 +163,21 @@ static void *virt_get_pte(struct kvm_vm *vm, uint64_t pt_pfn, uint64_t vaddr, return &page_table[index]; } -static struct pageUpperEntry *virt_create_upper_pte(struct kvm_vm *vm, - uint64_t pt_pfn, - uint64_t vaddr, - uint64_t paddr, - int level, - enum x86_page_size page_size) +static uint64_t *virt_create_upper_pte(struct kvm_vm *vm, + uint64_t pt_pfn, + uint64_t vaddr, + uint64_t paddr, + int level, + enum x86_page_size page_size) { - struct pageUpperEntry *pte = virt_get_pte(vm, pt_pfn, vaddr, level); - - if (!pte->present) { - pte->writable = true; - pte->present = true; - pte->page_size = (level == page_size); - if (pte->page_size) - pte->pfn = paddr >> vm->page_shift; + uint64_t *pte = virt_get_pte(vm, pt_pfn, vaddr, level); + + if (!(*pte & PTE_PRESENT_MASK)) { + *pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK; + if (level == page_size) + *pte |= PTE_LARGE_MASK | (paddr & PHYSICAL_PAGE_MASK); else - pte->pfn = vm_alloc_page_table(vm) >> vm->page_shift; + *pte |= vm_alloc_page_table(vm) & PHYSICAL_PAGE_MASK; } else { /* * Entry already present. Assert that the caller doesn't want @@ -221,7 +187,7 @@ static struct pageUpperEntry *virt_create_upper_pte(struct kvm_vm *vm, TEST_ASSERT(level != page_size, "Cannot create hugepage at level: %u, vaddr: 0x%lx\n", page_size, vaddr); - TEST_ASSERT(!pte->page_size, + TEST_ASSERT(!(*pte & PTE_LARGE_MASK), "Cannot create page table at level: %u, vaddr: 0x%lx\n", level, vaddr); } @@ -232,8 +198,8 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, enum x86_page_size page_size) { const uint64_t pg_size = 1ull << ((page_size * 9) + 12); - struct pageUpperEntry *pml4e, *pdpe, *pde; - struct pageTableEntry *pte; + uint64_t *pml4e, *pdpe, *pde; + uint64_t *pte; TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Unknown or unsupported guest mode, mode: 0x%x", vm->mode); @@ -257,24 +223,22 @@ void __virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr, */ pml4e = virt_create_upper_pte(vm, vm->pgd >> vm->page_shift, vaddr, paddr, 3, page_size); - if (pml4e->page_size) + if (*pml4e & PTE_LARGE_MASK) return; - pdpe = virt_create_upper_pte(vm, pml4e->pfn, vaddr, paddr, 2, page_size); - if (pdpe->page_size) + pdpe = virt_create_upper_pte(vm, PTE_GET_PFN(*pml4e), vaddr, paddr, 2, page_size); + if (*pdpe & PTE_LARGE_MASK) return; - pde = virt_create_upper_pte(vm, pdpe->pfn, vaddr, paddr, 1, page_size); - if (pde->page_size) + pde = virt_create_upper_pte(vm, PTE_GET_PFN(*pdpe), vaddr, paddr, 1, page_size); + if (*pde & PTE_LARGE_MASK) return; /* Fill in page table entry. */ - pte = virt_get_pte(vm, pde->pfn, vaddr, 0); - TEST_ASSERT(!pte->present, + pte = virt_get_pte(vm, PTE_GET_PFN(*pde), vaddr, 0); + TEST_ASSERT(!(*pte & PTE_PRESENT_MASK), "PTE already present for 4k page at vaddr: 0x%lx\n", vaddr); - pte->pfn = paddr >> vm->page_shift; - pte->writable = true; - pte->present = 1; + *pte = PTE_PRESENT_MASK | PTE_WRITABLE_MASK | (paddr & PHYSICAL_PAGE_MASK); } void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr) @@ -282,12 +246,12 @@ void virt_pg_map(struct kvm_vm *vm, uint64_t vaddr, uint64_t paddr) __virt_pg_map(vm, vaddr, paddr, X86_PAGE_SIZE_4K); } -static struct pageTableEntry *_vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid, +static uint64_t *_vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr) { uint16_t index[4]; - struct pageUpperEntry *pml4e, *pdpe, *pde; - struct pageTableEntry *pte; + uint64_t *pml4e, *pdpe, *pde; + uint64_t *pte; struct kvm_cpuid_entry2 *entry; struct kvm_sregs sregs; int max_phy_addr; @@ -329,30 +293,29 @@ static struct pageTableEntry *_vm_get_page_table_entry(struct kvm_vm *vm, int vc index[3] = (vaddr >> 39) & 0x1ffu; pml4e = addr_gpa2hva(vm, vm->pgd); - TEST_ASSERT(pml4e[index[3]].present, + TEST_ASSERT(pml4e[index[3]] & PTE_PRESENT_MASK, "Expected pml4e to be present for gva: 0x%08lx", vaddr); - TEST_ASSERT((*(uint64_t*)(&pml4e[index[3]]) & - (rsvd_mask | (1ull << 7))) == 0, + TEST_ASSERT((pml4e[index[3]] & (rsvd_mask | PTE_LARGE_MASK)) == 0, "Unexpected reserved bits set."); - pdpe = addr_gpa2hva(vm, pml4e[index[3]].pfn * vm->page_size); - TEST_ASSERT(pdpe[index[2]].present, + pdpe = addr_gpa2hva(vm, PTE_GET_PFN(pml4e[index[3]]) * vm->page_size); + TEST_ASSERT(pdpe[index[2]] & PTE_PRESENT_MASK, "Expected pdpe to be present for gva: 0x%08lx", vaddr); - TEST_ASSERT(pdpe[index[2]].page_size == 0, + TEST_ASSERT(!(pdpe[index[2]] & PTE_LARGE_MASK), "Expected pdpe to map a pde not a 1-GByte page."); - TEST_ASSERT((*(uint64_t*)(&pdpe[index[2]]) & rsvd_mask) == 0, + TEST_ASSERT((pdpe[index[2]] & rsvd_mask) == 0, "Unexpected reserved bits set."); - pde = addr_gpa2hva(vm, pdpe[index[2]].pfn * vm->page_size); - TEST_ASSERT(pde[index[1]].present, + pde = addr_gpa2hva(vm, PTE_GET_PFN(pdpe[index[2]]) * vm->page_size); + TEST_ASSERT(pde[index[1]] & PTE_PRESENT_MASK, "Expected pde to be present for gva: 0x%08lx", vaddr); - TEST_ASSERT(pde[index[1]].page_size == 0, + TEST_ASSERT(!(pde[index[1]] & PTE_LARGE_MASK), "Expected pde to map a pte not a 2-MByte page."); - TEST_ASSERT((*(uint64_t*)(&pde[index[1]]) & rsvd_mask) == 0, + TEST_ASSERT((pde[index[1]] & rsvd_mask) == 0, "Unexpected reserved bits set."); - pte = addr_gpa2hva(vm, pde[index[1]].pfn * vm->page_size); - TEST_ASSERT(pte[index[0]].present, + pte = addr_gpa2hva(vm, PTE_GET_PFN(pde[index[1]]) * vm->page_size); + TEST_ASSERT(pte[index[0]] & PTE_PRESENT_MASK, "Expected pte to be present for gva: 0x%08lx", vaddr); return &pte[index[0]]; @@ -360,7 +323,7 @@ static struct pageTableEntry *_vm_get_page_table_entry(struct kvm_vm *vm, int vc uint64_t vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr) { - struct pageTableEntry *pte = _vm_get_page_table_entry(vm, vcpuid, vaddr); + uint64_t *pte = _vm_get_page_table_entry(vm, vcpuid, vaddr); return *(uint64_t *)pte; } @@ -368,18 +331,17 @@ uint64_t vm_get_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr) void vm_set_page_table_entry(struct kvm_vm *vm, int vcpuid, uint64_t vaddr, uint64_t pte) { - struct pageTableEntry *new_pte = _vm_get_page_table_entry(vm, vcpuid, - vaddr); + uint64_t *new_pte = _vm_get_page_table_entry(vm, vcpuid, vaddr); *(uint64_t *)new_pte = pte; } void virt_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent) { - struct pageUpperEntry *pml4e, *pml4e_start; - struct pageUpperEntry *pdpe, *pdpe_start; - struct pageUpperEntry *pde, *pde_start; - struct pageTableEntry *pte, *pte_start; + uint64_t *pml4e, *pml4e_start; + uint64_t *pdpe, *pdpe_start; + uint64_t *pde, *pde_start; + uint64_t *pte, *pte_start; if (!vm->pgd_created) return; @@ -389,58 +351,58 @@ void virt_dump(FILE *stream, struct kvm_vm *vm, uint8_t indent) fprintf(stream, "%*s index hvaddr gpaddr " "addr w exec dirty\n", indent, ""); - pml4e_start = (struct pageUpperEntry *) addr_gpa2hva(vm, vm->pgd); + pml4e_start = (uint64_t *) addr_gpa2hva(vm, vm->pgd); for (uint16_t n1 = 0; n1 <= 0x1ffu; n1++) { pml4e = &pml4e_start[n1]; - if (!pml4e->present) + if (!(*pml4e & PTE_PRESENT_MASK)) continue; - fprintf(stream, "%*spml4e 0x%-3zx %p 0x%-12lx 0x%-10lx %u " + fprintf(stream, "%*spml4e 0x%-3zx %p 0x%-12lx 0x%-10llx %u " " %u\n", indent, "", pml4e - pml4e_start, pml4e, - addr_hva2gpa(vm, pml4e), (uint64_t) pml4e->pfn, - pml4e->writable, pml4e->execute_disable); + addr_hva2gpa(vm, pml4e), PTE_GET_PFN(*pml4e), + !!(*pml4e & PTE_WRITABLE_MASK), !!(*pml4e & PTE_NX_MASK)); - pdpe_start = addr_gpa2hva(vm, pml4e->pfn * vm->page_size); + pdpe_start = addr_gpa2hva(vm, *pml4e & PHYSICAL_PAGE_MASK); for (uint16_t n2 = 0; n2 <= 0x1ffu; n2++) { pdpe = &pdpe_start[n2]; - if (!pdpe->present) + if (!(*pdpe & PTE_PRESENT_MASK)) continue; - fprintf(stream, "%*spdpe 0x%-3zx %p 0x%-12lx 0x%-10lx " + fprintf(stream, "%*spdpe 0x%-3zx %p 0x%-12lx 0x%-10llx " "%u %u\n", indent, "", pdpe - pdpe_start, pdpe, addr_hva2gpa(vm, pdpe), - (uint64_t) pdpe->pfn, pdpe->writable, - pdpe->execute_disable); + PTE_GET_PFN(*pdpe), !!(*pdpe & PTE_WRITABLE_MASK), + !!(*pdpe & PTE_NX_MASK)); - pde_start = addr_gpa2hva(vm, pdpe->pfn * vm->page_size); + pde_start = addr_gpa2hva(vm, *pdpe & PHYSICAL_PAGE_MASK); for (uint16_t n3 = 0; n3 <= 0x1ffu; n3++) { pde = &pde_start[n3]; - if (!pde->present) + if (!(*pde & PTE_PRESENT_MASK)) continue; fprintf(stream, "%*spde 0x%-3zx %p " - "0x%-12lx 0x%-10lx %u %u\n", + "0x%-12lx 0x%-10llx %u %u\n", indent, "", pde - pde_start, pde, addr_hva2gpa(vm, pde), - (uint64_t) pde->pfn, pde->writable, - pde->execute_disable); + PTE_GET_PFN(*pde), !!(*pde & PTE_WRITABLE_MASK), + !!(*pde & PTE_NX_MASK)); - pte_start = addr_gpa2hva(vm, pde->pfn * vm->page_size); + pte_start = addr_gpa2hva(vm, *pde & PHYSICAL_PAGE_MASK); for (uint16_t n4 = 0; n4 <= 0x1ffu; n4++) { pte = &pte_start[n4]; - if (!pte->present) + if (!(*pte & PTE_PRESENT_MASK)) continue; fprintf(stream, "%*spte 0x%-3zx %p " - "0x%-12lx 0x%-10lx %u %u " + "0x%-12lx 0x%-10llx %u %u " " %u 0x%-10lx\n", indent, "", pte - pte_start, pte, addr_hva2gpa(vm, pte), - (uint64_t) pte->pfn, - pte->writable, - pte->execute_disable, - pte->dirty, + PTE_GET_PFN(*pte), + !!(*pte & PTE_WRITABLE_MASK), + !!(*pte & PTE_NX_MASK), + !!(*pte & PTE_DIRTY_MASK), ((uint64_t) n1 << 27) | ((uint64_t) n2 << 18) | ((uint64_t) n3 << 9) @@ -558,8 +520,8 @@ static void kvm_seg_set_kernel_data_64bit(struct kvm_vm *vm, uint16_t selector, vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva) { uint16_t index[4]; - struct pageUpperEntry *pml4e, *pdpe, *pde; - struct pageTableEntry *pte; + uint64_t *pml4e, *pdpe, *pde; + uint64_t *pte; TEST_ASSERT(vm->mode == VM_MODE_PXXV48_4K, "Attempt to use " "unknown or unsupported guest mode, mode: 0x%x", vm->mode); @@ -572,22 +534,22 @@ vm_paddr_t addr_gva2gpa(struct kvm_vm *vm, vm_vaddr_t gva) if (!vm->pgd_created) goto unmapped_gva; pml4e = addr_gpa2hva(vm, vm->pgd); - if (!pml4e[index[3]].present) + if (!(pml4e[index[3]] & PTE_PRESENT_MASK)) goto unmapped_gva; - pdpe = addr_gpa2hva(vm, pml4e[index[3]].pfn * vm->page_size); - if (!pdpe[index[2]].present) + pdpe = addr_gpa2hva(vm, PTE_GET_PFN(pml4e[index[3]]) * vm->page_size); + if (!(pdpe[index[2]] & PTE_PRESENT_MASK)) goto unmapped_gva; - pde = addr_gpa2hva(vm, pdpe[index[2]].pfn * vm->page_size); - if (!pde[index[1]].present) + pde = addr_gpa2hva(vm, PTE_GET_PFN(pdpe[index[2]]) * vm->page_size); + if (!(pde[index[1]] & PTE_PRESENT_MASK)) goto unmapped_gva; - pte = addr_gpa2hva(vm, pde[index[1]].pfn * vm->page_size); - if (!pte[index[0]].present) + pte = addr_gpa2hva(vm, PTE_GET_PFN(pde[index[1]]) * vm->page_size); + if (!(pte[index[0]] & PTE_PRESENT_MASK)) goto unmapped_gva; - return (pte[index[0]].pfn * vm->page_size) + (gva & 0xfffu); + return (PTE_GET_PFN(pte[index[0]]) * vm->page_size) + (gva & 0xfffu); unmapped_gva: TEST_FAIL("No mapping for vm virtual address, gva: 0x%lx", gva); -- 2.35.1

3 years, 6 months

2
5
0 0

[PATCH v5 1/3] selftests: bpf: add test for bpf_skb_change_proto

by Lina Wang

The code is copied from the Android Open Source Project and the author( Maciej ��enczykowski) has gave permission to relicense it under GPLv2. The test is to change input IPv6 packets to IPv4 ones and output IPv4 to IPv6 with bpf_skb_change_proto. Signed-off-by: Maciej ��enczykowski <maze(a)google.com> Signed-off-by: Lina Wang <lina.wang(a)mediatek.com> --- tools/testing/selftests/bpf/progs/nat6to4.c | 293 ++++++++++++++++++++ 1 file changed, 293 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/nat6to4.c diff --git a/tools/testing/selftests/bpf/progs/nat6to4.c b/tools/testing/selftests/bpf/progs/nat6to4.c new file mode 100644 index 000000000000..099950f7a6cc --- /dev/null +++ b/tools/testing/selftests/bpf/progs/nat6to4.c @@ -0,0 +1,293 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This code is taken from the Android Open Source Project and the author + * (Maciej ��enczykowski) has gave permission to relicense it under the + * GPLv2. Therefore this program is free software; + * You can redistribute it and/or modify it under the terms of the GNU + * General Public License version 2 as published by the Free Software + * Foundation + + * The original headers, including the original license headers, are + * included below for completeness. + * + * Copyright (C) 2019 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#include <linux/bpf.h> +#include <linux/if.h> +#include <linux/if_ether.h> +#include <linux/if_packet.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/pkt_cls.h> +#include <linux/swab.h> +#include <stdbool.h> +#include <stdint.h> + +// bionic kernel uapi linux/udp.h header is munged... +#define __kernel_udphdr udphdr +#include <linux/udp.h> + +#include <bpf/bpf_helpers.h> + +#define htons(x) (__builtin_constant_p(x) ? ___constant_swab16(x) : __builtin_bswap16(x)) +#define htonl(x) (__builtin_constant_p(x) ? ___constant_swab32(x) : __builtin_bswap32(x)) +#define ntohs(x) htons(x) +#define ntohl(x) htonl(x) + +// From kernel:include/net/ip.h +#define IP_DF 0x4000 // Flag: "Don't Fragment" + +SEC("schedcls/ingress6/nat_6") +int sched_cls_ingress6_nat_6_prog(struct __sk_buff *skb) +{ + + const int l2_header_size = sizeof(struct ethhdr); + void *data = (void *)(long)skb->data; + const void *data_end = (void *)(long)skb->data_end; + const struct ethhdr * const eth = data; // used iff is_ethernet + const struct ipv6hdr * const ip6 = (void *)(eth + 1); + + // Require ethernet dst mac address to be our unicast address. + if (skb->pkt_type != PACKET_HOST) + return TC_ACT_OK; + + // Must be meta-ethernet IPv6 frame + if (skb->protocol != htons(ETH_P_IPV6)) + return TC_ACT_OK; + + // Must have (ethernet and) ipv6 header + if (data + l2_header_size + sizeof(*ip6) > data_end) + return TC_ACT_OK; + + // Ethertype - if present - must be IPv6 + if (eth->h_proto != htons(ETH_P_IPV6)) + return TC_ACT_OK; + + // IP version must be 6 + if (ip6->version != 6) + return TC_ACT_OK; + // Maximum IPv6 payload length that can be translated to IPv4 + if (ntohs(ip6->payload_len) > 0xFFFF - sizeof(struct iphdr)) + return TC_ACT_OK; + switch (ip6->nexthdr) { + case IPPROTO_TCP: // For TCP & UDP the checksum neutrality of the chosen IPv6 + case IPPROTO_UDP: // address means there is no need to update their checksums. + case IPPROTO_GRE: // We do not need to bother looking at GRE/ESP headers, + case IPPROTO_ESP: // since there is never a checksum to update. + break; + default: // do not know how to handle anything else + return TC_ACT_OK; + } + + struct ethhdr eth2; // used iff is_ethernet + + eth2 = *eth; // Copy over the ethernet header (src/dst mac) + eth2.h_proto = htons(ETH_P_IP); // But replace the ethertype + + struct iphdr ip = { + .version = 4, // u4 + .ihl = sizeof(struct iphdr) / sizeof(__u32), // u4 + .tos = (ip6->priority << 4) + (ip6->flow_lbl[0] >> 4), // u8 + .tot_len = htons(ntohs(ip6->payload_len) + sizeof(struct iphdr)), // u16 + .id = 0, // u16 + .frag_off = htons(IP_DF), // u16 + .ttl = ip6->hop_limit, // u8 + .protocol = ip6->nexthdr, // u8 + .check = 0, // u16 + .saddr = 0x0201a8c0, // u32 + .daddr = 0x0101a8c0, // u32 + }; + + // Calculate the IPv4 one's complement checksum of the IPv4 header. + __wsum sum4 = 0; + + for (int i = 0; i < sizeof(ip) / sizeof(__u16); ++i) + sum4 += ((__u16 *)&ip)[i]; + + // Note that sum4 is guaranteed to be non-zero by virtue of ip.version == 4 + sum4 = (sum4 & 0xFFFF) + (sum4 >> 16); // collapse u32 into range 1 .. 0x1FFFE + sum4 = (sum4 & 0xFFFF) + (sum4 >> 16); // collapse any potential carry into u16 + ip.check = (__u16)~sum4; // sum4 cannot be zero, so this is never 0xFFFF + + // Calculate the *negative* IPv6 16-bit one's complement checksum of the IPv6 header. + __wsum sum6 = 0; + // We'll end up with a non-zero sum due to ip6->version == 6 (which has '0' bits) + for (int i = 0; i < sizeof(*ip6) / sizeof(__u16); ++i) + sum6 += ~((__u16 *)ip6)[i]; // note the bitwise negation + + // Note that there is no L4 checksum update: we are relying on the checksum neutrality + // of the ipv6 address chosen by netd's ClatdController. + + // Packet mutations begin - point of no return, but if this first modification fails + // the packet is probably still pristine, so let clatd handle it. + if (bpf_skb_change_proto(skb, htons(ETH_P_IP), 0)) + return TC_ACT_OK; + bpf_csum_update(skb, sum6); + + data = (void *)(long)skb->data; + data_end = (void *)(long)skb->data_end; + if (data + l2_header_size + sizeof(struct iphdr) > data_end) + return TC_ACT_SHOT; + + struct ethhdr *new_eth = data; + + // Copy over the updated ethernet header + *new_eth = eth2; + + // Copy over the new ipv4 header. + *(struct iphdr *)(new_eth + 1) = ip; + return bpf_redirect(skb->ifindex, BPF_F_INGRESS); +} +SEC("schedcls/egress4/snat4") +int sched_cls_egress4_snat4_prog(struct __sk_buff *skb) +{ + const int l2_header_size = sizeof(struct ethhdr); + void *data = (void *)(long)skb->data; + const void *data_end = (void *)(long)skb->data_end; + const struct ethhdr *const eth = data; // used iff is_ethernet + const struct iphdr *const ip4 = (void *)(eth + 1); + + + // Must be meta-ethernet IPv4 frame + if (skb->protocol != htons(ETH_P_IP)) + return TC_ACT_OK; + + // Must have ipv4 header + if (data + l2_header_size + sizeof(struct ipv6hdr) > data_end) + return TC_ACT_OK; + + // Ethertype - if present - must be IPv4 + if (eth->h_proto != htons(ETH_P_IP)) + return TC_ACT_OK; + + // IP version must be 4 + if (ip4->version != 4) + return TC_ACT_OK; + + // We cannot handle IP options, just standard 20 byte == 5 dword minimal IPv4 header + if (ip4->ihl != 5) + return TC_ACT_OK; + + // Maximum IPv6 payload length that can be translated to IPv4 + if (htons(ip4->tot_len) > 0xFFFF - sizeof(struct ipv6hdr)) + return TC_ACT_OK; + + // Calculate the IPv4 one's complement checksum of the IPv4 header. + __wsum sum4 = 0; + + for (int i = 0; i < sizeof(*ip4) / sizeof(__u16); ++i) + sum4 += ((__u16 *)ip4)[i]; + + // Note that sum4 is guaranteed to be non-zero by virtue of ip4->version == 4 + sum4 = (sum4 & 0xFFFF) + (sum4 >> 16); // collapse u32 into range 1 .. 0x1FFFE + sum4 = (sum4 & 0xFFFF) + (sum4 >> 16); // collapse any potential carry into u16 + // for a correct checksum we should get *a* zero, but sum4 must be positive, ie 0xFFFF + if (sum4 != 0xFFFF) + return TC_ACT_OK; + + // Minimum IPv4 total length is the size of the header + if (ntohs(ip4->tot_len) < sizeof(*ip4)) + return TC_ACT_OK; + + // We are incapable of dealing with IPv4 fragments + if (ip4->frag_off & ~htons(IP_DF)) + return TC_ACT_OK; + + switch (ip4->protocol) { + case IPPROTO_TCP: // For TCP & UDP the checksum neutrality of the chosen IPv6 + case IPPROTO_GRE: // address means there is no need to update their checksums. + case IPPROTO_ESP: // We do not need to bother looking at GRE/ESP headers, + break; // since there is never a checksum to update. + + case IPPROTO_UDP: // See above comment, but must also have UDP header... + if (data + sizeof(*ip4) + sizeof(struct udphdr) > data_end) + return TC_ACT_OK; + const struct udphdr *uh = (const struct udphdr *)(ip4 + 1); + // If IPv4/UDP checksum is 0 then fallback to clatd so it can calculate the + // checksum. Otherwise the network or more likely the NAT64 gateway might + // drop the packet because in most cases IPv6/UDP packets with a zero checksum + // are invalid. See RFC 6935. TODO: calculate checksum via bpf_csum_diff() + if (!uh->check) + return TC_ACT_OK; + break; + + default: // do not know how to handle anything else + return TC_ACT_OK; + } + struct ethhdr eth2; // used iff is_ethernet + + eth2 = *eth; // Copy over the ethernet header (src/dst mac) + eth2.h_proto = htons(ETH_P_IPV6); // But replace the ethertype + + struct ipv6hdr ip6 = { + .version = 6, // __u8:4 + .priority = ip4->tos >> 4, // __u8:4 + .flow_lbl = {(ip4->tos & 0xF) << 4, 0, 0}, // __u8[3] + .payload_len = htons(ntohs(ip4->tot_len) - 20), // __be16 + .nexthdr = ip4->protocol, // __u8 + .hop_limit = ip4->ttl, // __u8 + }; + ip6.saddr.in6_u.u6_addr32[0] = htonl(0x20010db8); + ip6.saddr.in6_u.u6_addr32[1] = 0; + ip6.saddr.in6_u.u6_addr32[2] = 0; + ip6.saddr.in6_u.u6_addr32[3] = htonl(1); + ip6.daddr.in6_u.u6_addr32[0] = htonl(0x20010db8); + ip6.daddr.in6_u.u6_addr32[1] = 0; + ip6.daddr.in6_u.u6_addr32[2] = 0; + ip6.daddr.in6_u.u6_addr32[3] = htonl(2); + + // Calculate the IPv6 16-bit one's complement checksum of the IPv6 header. + __wsum sum6 = 0; + // We'll end up with a non-zero sum due to ip6.version == 6 + for (int i = 0; i < sizeof(ip6) / sizeof(__u16); ++i) + sum6 += ((__u16 *)&ip6)[i]; + + // Packet mutations begin - point of no return, but if this first modification fails + // the packet is probably still pristine, so let clatd handle it. + if (bpf_skb_change_proto(skb, htons(ETH_P_IPV6), 0)) + return TC_ACT_OK; + + // This takes care of updating the skb->csum field for a CHECKSUM_COMPLETE packet. + // In such a case, skb->csum is a 16-bit one's complement sum of the entire payload, + // thus we need to subtract out the ipv4 header's sum, and add in the ipv6 header's sum. + // However, we've already verified the ipv4 checksum is correct and thus 0. + // Thus we only need to add the ipv6 header's sum. + // + // bpf_csum_update() always succeeds if the skb is CHECKSUM_COMPLETE and returns an error + // (-ENOTSUPP) if it isn't. So we just ignore the return code (see above for more details). + bpf_csum_update(skb, sum6); + + // bpf_skb_change_proto() invalidates all pointers - reload them. + data = (void *)(long)skb->data; + data_end = (void *)(long)skb->data_end; + + // I cannot think of any valid way for this error condition to trigger, however I do + // believe the explicit check is required to keep the in kernel ebpf verifier happy. + if (data + l2_header_size + sizeof(ip6) > data_end) + return TC_ACT_SHOT; + + struct ethhdr *new_eth = data; + + // Copy over the updated ethernet header + *new_eth = eth2; + // Copy over the new ipv4 header. + *(struct ipv6hdr *)(new_eth + 1) = ip6; + return TC_ACT_OK; +} + +char _license[] SEC("license") = ("GPL"); + -- 2.18.0

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