Commit 8bfec4f3 authored by Daniel Borkmann's avatar Daniel Borkmann
Browse files

Merge branch 'bpf-sockaddr-wide-store' 



Stanislav Fomichev says:

====================
Clang can generate 8-byte stores for user_ip6 & msg_src_ip6,
let's support that on the verifier side.

v3:
* fix comments spelling an -> and (Andrii Nakryiko)

v2:
* Add simple cover letter (Yonghong Song)
* Update comments (Yonghong Song)
* Remove [4] selftests (Yonghong Song)
====================

Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
parents d2850ce0 76d95077

include/linux/filter.h

+6 −0
Original line number Diff line number Diff line
@@ -747,6 +747,12 @@ bpf_ctx_narrow_access_ok(u32 off, u32 size, u32 size_default) 
	return size <= size_default && (size & (size - 1)) == 0;

}



#define bpf_ctx_wide_store_ok(off, size, type, field)			\

	(size == sizeof(__u64) &&					\

	off >= offsetof(type, field) &&					\

	off + sizeof(__u64) <= offsetofend(type, field) &&		\

	off % sizeof(__u64) == 0)



#define bpf_classic_proglen(fprog) (fprog->len * sizeof(fprog->filter[0]))



static inline void bpf_prog_lock_ro(struct bpf_prog *fp)

include/uapi/linux/bpf.h

+3 −3
Original line number Diff line number Diff line
@@ -3247,7 +3247,7 @@ struct bpf_sock_addr { 
	__u32 user_ip4;		/* Allows 1,2,4-byte read and 4-byte write.

				 * Stored in network byte order.

				 */

	__u32 user_ip6[4];	/* Allows 1,2,4-byte read an 4-byte write.

	__u32 user_ip6[4];	/* Allows 1,2,4-byte read and 4,8-byte write.

				 * Stored in network byte order.

				 */

	__u32 user_port;	/* Allows 4-byte read and write.
@@ -3256,10 +3256,10 @@ struct bpf_sock_addr { 
	__u32 family;		/* Allows 4-byte read, but no write */

	__u32 type;		/* Allows 4-byte read, but no write */

	__u32 protocol;		/* Allows 4-byte read, but no write */

	__u32 msg_src_ip4;	/* Allows 1,2,4-byte read an 4-byte write.

	__u32 msg_src_ip4;	/* Allows 1,2,4-byte read and 4-byte write.

				 * Stored in network byte order.

				 */

	__u32 msg_src_ip6[4];	/* Allows 1,2,4-byte read an 4-byte write.

	__u32 msg_src_ip6[4];	/* Allows 1,2,4-byte read and 4,8-byte write.

				 * Stored in network byte order.

				 */

	__bpf_md_ptr(struct bpf_sock *, sk);

net/core/filter.c

+14 −8
Original line number Diff line number Diff line
@@ -6890,6 +6890,16 @@ static bool sock_addr_is_valid_access(int off, int size, 
			if (!bpf_ctx_narrow_access_ok(off, size, size_default))

				return false;

		} else {

			if (bpf_ctx_wide_store_ok(off, size,

						  struct bpf_sock_addr,

						  user_ip6))

				return true;



			if (bpf_ctx_wide_store_ok(off, size,

						  struct bpf_sock_addr,

						  msg_src_ip6))

				return true;



			if (size != size_default)

				return false;

		}
@@ -7730,9 +7740,6 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type, 
/* SOCK_ADDR_STORE_NESTED_FIELD_OFF() has semantic similar to

 * SOCK_ADDR_LOAD_NESTED_FIELD_SIZE_OFF() but for store operation.

 *

 * It doesn't support SIZE argument though since narrow stores are not

 * supported for now.

 *

 * In addition it uses Temporary Field TF (member of struct S) as the 3rd

 * "register" since two registers available in convert_ctx_access are not

 * enough: we can't override neither SRC, since it contains value to store, nor
@@ -7740,7 +7747,7 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type, 
 * instructions. But we need a temporary place to save pointer to nested

 * structure whose field we want to store to.

 */

#define SOCK_ADDR_STORE_NESTED_FIELD_OFF(S, NS, F, NF, OFF, TF)		       \

#define SOCK_ADDR_STORE_NESTED_FIELD_OFF(S, NS, F, NF, SIZE, OFF, TF)	       \

	do {								       \

		int tmp_reg = BPF_REG_9;				       \

		if (si->src_reg == tmp_reg || si->dst_reg == tmp_reg)	       \
@@ -7751,8 +7758,7 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type, 
				      offsetof(S, TF));			       \

		*insn++ = BPF_LDX_MEM(BPF_FIELD_SIZEOF(S, F), tmp_reg,	       \

				      si->dst_reg, offsetof(S, F));	       \

		*insn++ = BPF_STX_MEM(					       \

			BPF_FIELD_SIZEOF(NS, NF), tmp_reg, si->src_reg,	       \

		*insn++ = BPF_STX_MEM(SIZE, tmp_reg, si->src_reg,	       \

			bpf_target_off(NS, NF, FIELD_SIZEOF(NS, NF),	       \

				       target_size)			       \

				+ OFF);					       \
@@ -7764,8 +7770,8 @@ static u32 xdp_convert_ctx_access(enum bpf_access_type type, 
						      TF)		       \

	do {								       \

		if (type == BPF_WRITE) {				       \

			SOCK_ADDR_STORE_NESTED_FIELD_OFF(S, NS, F, NF, OFF,    \

							 TF);		       \

			SOCK_ADDR_STORE_NESTED_FIELD_OFF(S, NS, F, NF, SIZE,   \

							 OFF, TF);	       \

		} else {						       \

			SOCK_ADDR_LOAD_NESTED_FIELD_SIZE_OFF(		       \

				S, NS, F, NF, SIZE, OFF);  \

tools/include/uapi/linux/bpf.h

+3 −3
Original line number Diff line number Diff line
@@ -3244,7 +3244,7 @@ struct bpf_sock_addr { 
	__u32 user_ip4;		/* Allows 1,2,4-byte read and 4-byte write.

				 * Stored in network byte order.

				 */

	__u32 user_ip6[4];	/* Allows 1,2,4-byte read an 4-byte write.

	__u32 user_ip6[4];	/* Allows 1,2,4-byte read and 4,8-byte write.

				 * Stored in network byte order.

				 */

	__u32 user_port;	/* Allows 4-byte read and write.
@@ -3253,10 +3253,10 @@ struct bpf_sock_addr { 
	__u32 family;		/* Allows 4-byte read, but no write */

	__u32 type;		/* Allows 4-byte read, but no write */

	__u32 protocol;		/* Allows 4-byte read, but no write */

	__u32 msg_src_ip4;	/* Allows 1,2,4-byte read an 4-byte write.

	__u32 msg_src_ip4;	/* Allows 1,2,4-byte read and 4-byte write.

				 * Stored in network byte order.

				 */

	__u32 msg_src_ip6[4];	/* Allows 1,2,4-byte read an 4-byte write.

	__u32 msg_src_ip6[4];	/* Allows 1,2,4-byte read and 4,8-byte write.

				 * Stored in network byte order.

				 */

	__bpf_md_ptr(struct bpf_sock *, sk);

tools/testing/selftests/bpf/test_verifier.c

+14 −3
Original line number Diff line number Diff line
@@ -105,6 +105,7 @@ struct bpf_test { 
			__u64 data64[TEST_DATA_LEN / 8];

		};

	} retvals[MAX_TEST_RUNS];

	enum bpf_attach_type expected_attach_type;

};



/* Note we want this to be 64 bit aligned so that the end of our array is
@@ -850,6 +851,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv, 
	int fd_prog, expected_ret, alignment_prevented_execution;

	int prog_len, prog_type = test->prog_type;

	struct bpf_insn *prog = test->insns;

	struct bpf_load_program_attr attr;

	int run_errs, run_successes;

	int map_fds[MAX_NR_MAPS];

	const char *expected_err;
@@ -881,8 +883,17 @@ static void do_test_single(struct bpf_test *test, bool unpriv, 
		pflags |= BPF_F_STRICT_ALIGNMENT;

	if (test->flags & F_NEEDS_EFFICIENT_UNALIGNED_ACCESS)

		pflags |= BPF_F_ANY_ALIGNMENT;

	fd_prog = bpf_verify_program(prog_type, prog, prog_len, pflags,

				     "GPL", 0, bpf_vlog, sizeof(bpf_vlog), 4);



	memset(&attr, 0, sizeof(attr));

	attr.prog_type = prog_type;

	attr.expected_attach_type = test->expected_attach_type;

	attr.insns = prog;

	attr.insns_cnt = prog_len;

	attr.license = "GPL";

	attr.log_level = 4;

	attr.prog_flags = pflags;



	fd_prog = bpf_load_program_xattr(&attr, bpf_vlog, sizeof(bpf_vlog));

	if (fd_prog < 0 && !bpf_probe_prog_type(prog_type, 0)) {

		printf("SKIP (unsupported program type %d)\n", prog_type);

		skips++;
@@ -912,7 +923,7 @@ static void do_test_single(struct bpf_test *test, bool unpriv, 
			printf("FAIL\nUnexpected success to load!\n");

			goto fail_log;

		}

		if (!strstr(bpf_vlog, expected_err)) {

		if (!expected_err || !strstr(bpf_vlog, expected_err)) {

			printf("FAIL\nUnexpected error message!\n\tEXP: %s\n\tRES: %s\n",

			      expected_err, bpf_vlog);

			goto fail_log;

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