Message-ID: <20240422225024.2847039-4-vadfed@meta.com>
Date: Mon, 22 Apr 2024 15:50:23 -0700
From: Vadim Fedorenko <vadfed@...a.com>
To: Vadim Fedorenko <vadim.fedorenko@...ux.dev>,
        Jakub Kicinski
	<kuba@...nel.org>,
        Martin KaFai Lau <martin.lau@...ux.dev>,
        Andrii Nakryiko
	<andrii@...nel.org>,
        Alexei Starovoitov <ast@...nel.org>, Mykola Lysenko
	<mykolal@...com>,
        Herbert Xu <herbert@...dor.apana.org.au>
CC: Vadim Fedorenko <vadfed@...a.com>, <netdev@...r.kernel.org>,
        <linux-crypto@...r.kernel.org>, <bpf@...r.kernel.org>
Subject: [PATCH bpf-next v10 3/4] selftests: bpf: crypto skcipher algo selftests

Add simple tc hook selftests to show the way to work with new crypto
BPF API. Some tricky dynptr initialization is used to provide empty iv
dynptr. Simple AES-ECB algo is used to demonstrate encryption and
decryption of fixed size buffers.

Signed-off-by: Vadim Fedorenko <vadfed@...a.com>
---
v9 -> v10:
- reorder calls in tests to have proper error path
- change test programs to use global vars to fill bpf_crypto_params
  structure
- removed crypto_shared.h as there is no need for it anymore
- improved bpf_tc_detach part with error check
- improved comments about using bpf_dynptr in production
v8 -> v9:
- adjust tests to use new bpf_crypto_create API
v7 -> v8:
- use sizeof for all constant buffer operations
- make local functions static
- initialize crypto_key value via access to bss data
- add bpf_skb_pull_data to be sure that data is linear
- some comments around tricky dynptr initialization
v6 -> v7:
- style issues
v5 -> v6:
- use AF_ALG socket to confirm proper algorithm test
- adjust test kernel config to include AF_ALG
v4 -> v5:
- adjust selftests to use new naming
- restore tests on aarch64 and s390 as no sg lists are used
v3 -> v4:
- adjust selftests to use new syntax of helpers
- add tests for acquire and release
v2 -> v3:
- disable tests on s390 and aarch64 because of unknown Fatal exception
  in sg_init_one
v1 -> v2:
- add CONFIG_CRYPTO_AES and CONFIG_CRYPTO_ECB to selftest build config
  suggested by Daniel
---
 tools/testing/selftests/bpf/config            |   5 +
 .../selftests/bpf/prog_tests/crypto_sanity.c  | 197 ++++++++++++++++++
 .../selftests/bpf/progs/crypto_basic.c        |  68 ++++++
 .../selftests/bpf/progs/crypto_common.h       |  66 ++++++
 .../selftests/bpf/progs/crypto_sanity.c       | 169 +++++++++++++++
 5 files changed, 505 insertions(+)
 create mode 100644 tools/testing/selftests/bpf/prog_tests/crypto_sanity.c
 create mode 100644 tools/testing/selftests/bpf/progs/crypto_basic.c
 create mode 100644 tools/testing/selftests/bpf/progs/crypto_common.h
 create mode 100644 tools/testing/selftests/bpf/progs/crypto_sanity.c

diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config
index afd675b1bf80..eeabd798bc3a 100644
--- a/tools/testing/selftests/bpf/config
+++ b/tools/testing/selftests/bpf/config
@@ -13,7 +13,12 @@ CONFIG_BPF_SYSCALL=y
 CONFIG_CGROUP_BPF=y
 CONFIG_CRYPTO_HMAC=y
 CONFIG_CRYPTO_SHA256=y
+CONFIG_CRYPTO_USER_API=y
 CONFIG_CRYPTO_USER_API_HASH=y
+CONFIG_CRYPTO_USER_API_SKCIPHER=y
+CONFIG_CRYPTO_SKCIPHER=y
+CONFIG_CRYPTO_ECB=y
+CONFIG_CRYPTO_AES=y
 CONFIG_DEBUG_INFO=y
 CONFIG_DEBUG_INFO_BTF=y
 CONFIG_DEBUG_INFO_DWARF4=y
diff --git a/tools/testing/selftests/bpf/prog_tests/crypto_sanity.c b/tools/testing/selftests/bpf/prog_tests/crypto_sanity.c
new file mode 100644
index 000000000000..b1a3a49a822a
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/crypto_sanity.c
@@ -0,0 +1,197 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <net/if.h>
+#include <linux/in6.h>
+#include <linux/if_alg.h>
+
+#include "test_progs.h"
+#include "network_helpers.h"
+#include "crypto_sanity.skel.h"
+#include "crypto_basic.skel.h"
+
+#define NS_TEST "crypto_sanity_ns"
+#define IPV6_IFACE_ADDR "face::1"
+static const unsigned char crypto_key[] = "testtest12345678";
+static const char plain_text[] = "stringtoencrypt0";
+static int opfd = -1, tfmfd = -1;
+static const char algo[] = "ecb(aes)";
+static int init_afalg(void)
+{
+	struct sockaddr_alg sa = {
+		.salg_family = AF_ALG,
+		.salg_type = "skcipher",
+		.salg_name = "ecb(aes)"
+	};
+
+	tfmfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
+	if (tfmfd == -1)
+		return errno;
+	if (bind(tfmfd, (struct sockaddr *)&sa, sizeof(sa)) == -1)
+		return errno;
+	if (setsockopt(tfmfd, SOL_ALG, ALG_SET_KEY, crypto_key, 16) == -1)
+		return errno;
+	opfd = accept(tfmfd, NULL, 0);
+	if (opfd == -1)
+		return errno;
+	return 0;
+}
+
+static void deinit_afalg(void)
+{
+	if (tfmfd != -1)
+		close(tfmfd);
+	if (opfd != -1)
+		close(opfd);
+}
+
+static void do_crypt_afalg(const void *src, void *dst, int size, bool encrypt)
+{
+	struct msghdr msg = {};
+	struct cmsghdr *cmsg;
+	char cbuf[CMSG_SPACE(4)] = {0};
+	struct iovec iov;
+
+	msg.msg_control = cbuf;
+	msg.msg_controllen = sizeof(cbuf);
+
+	cmsg = CMSG_FIRSTHDR(&msg);
+	cmsg->cmsg_level = SOL_ALG;
+	cmsg->cmsg_type = ALG_SET_OP;
+	cmsg->cmsg_len = CMSG_LEN(4);
+	*(__u32 *)CMSG_DATA(cmsg) = encrypt ? ALG_OP_ENCRYPT : ALG_OP_DECRYPT;
+
+	iov.iov_base = (char *)src;
+	iov.iov_len = size;
+
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+
+	sendmsg(opfd, &msg, 0);
+	read(opfd, dst, size);
+}
+
+void test_crypto_basic(void)
+{
+	RUN_TESTS(crypto_basic);
+}
+
+void test_crypto_sanity(void)
+{
+	LIBBPF_OPTS(bpf_tc_hook, qdisc_hook, .attach_point = BPF_TC_EGRESS);
+	LIBBPF_OPTS(bpf_tc_opts, tc_attach_enc);
+	LIBBPF_OPTS(bpf_tc_opts, tc_attach_dec);
+	LIBBPF_OPTS(bpf_test_run_opts, opts);
+	struct nstoken *nstoken = NULL;
+	struct crypto_sanity *skel;
+	char afalg_plain[16] = {0};
+	char afalg_dst[16] = {0};
+	struct sockaddr_in6 addr;
+	int sockfd, err, pfd;
+	socklen_t addrlen;
+	u16 udp_test_port;
+
+	skel = crypto_sanity__open_and_load();
+	if (!ASSERT_OK_PTR(skel, "skel open"))
+		return;
+
+	SYS(fail, "ip netns add %s", NS_TEST);
+	SYS(fail, "ip -net %s -6 addr add %s/128 dev lo nodad", NS_TEST, IPV6_IFACE_ADDR);
+	SYS(fail, "ip -net %s link set dev lo up", NS_TEST);
+
+	nstoken = open_netns(NS_TEST);
+	if (!ASSERT_OK_PTR(nstoken, "open_netns"))
+		goto fail;
+
+	err = init_afalg();
+	if (!ASSERT_OK(err, "AF_ALG init fail"))
+		goto fail;
+
+	qdisc_hook.ifindex = if_nametoindex("lo");
+	if (!ASSERT_GT(qdisc_hook.ifindex, 0, "if_nametoindex lo"))
+		goto fail;
+
+	skel->bss->key_len = 16;
+	skel->bss->authsize = 0;
+	udp_test_port = skel->data->udp_test_port;
+	memcpy(skel->bss->key, crypto_key, sizeof(crypto_key));
+	snprintf(skel->bss->algo, 128, "%s", algo);
+	pfd = bpf_program__fd(skel->progs.skb_crypto_setup);
+	if (!ASSERT_GT(pfd, 0, "skb_crypto_setup fd"))
+		goto fail;
+
+	err = bpf_prog_test_run_opts(pfd, &opts);
+	if (!ASSERT_OK(err, "skb_crypto_setup") ||
+	    !ASSERT_OK(opts.retval, "skb_crypto_setup retval"))
+		goto fail;
+
+	if (!ASSERT_OK(skel->bss->status, "skb_crypto_setup status"))
+		goto fail;
+
+	err = bpf_tc_hook_create(&qdisc_hook);
+	if (!ASSERT_OK(err, "create qdisc hook"))
+		goto fail;
+
+	addrlen = sizeof(addr);
+	err = make_sockaddr(AF_INET6, IPV6_IFACE_ADDR, udp_test_port,
+			    (void *)&addr, &addrlen);
+	if (!ASSERT_OK(err, "make_sockaddr"))
+		goto fail;
+
+	tc_attach_enc.prog_fd = bpf_program__fd(skel->progs.encrypt_sanity);
+	err = bpf_tc_attach(&qdisc_hook, &tc_attach_enc);
+	if (!ASSERT_OK(err, "attach encrypt filter"))
+		goto fail;
+
+	sockfd = socket(AF_INET6, SOCK_DGRAM, 0);
+	if (!ASSERT_NEQ(sockfd, -1, "encrypt socket"))
+		goto fail;
+	err = sendto(sockfd, plain_text, sizeof(plain_text), 0, (void *)&addr, addrlen);
+	close(sockfd);
+	if (!ASSERT_EQ(err, sizeof(plain_text), "encrypt send"))
+		goto fail;
+
+	do_crypt_afalg(plain_text, afalg_dst, sizeof(afalg_dst), true);
+
+	if (!ASSERT_OK(skel->bss->status, "encrypt status"))
+		goto fail;
+	if (!ASSERT_STRNEQ(skel->bss->dst, afalg_dst, sizeof(afalg_dst), "encrypt AF_ALG"))
+		goto fail;
+
+	tc_attach_enc.flags = tc_attach_enc.prog_fd = tc_attach_enc.prog_id = 0;
+	err = bpf_tc_detach(&qdisc_hook, &tc_attach_enc);
+	if (!ASSERT_OK(err, "bpf_tc_detach encrypt"))
+		goto fail;
+
+	tc_attach_dec.prog_fd = bpf_program__fd(skel->progs.decrypt_sanity);
+	err = bpf_tc_attach(&qdisc_hook, &tc_attach_dec);
+	if (!ASSERT_OK(err, "attach decrypt filter"))
+		goto fail;
+
+	sockfd = socket(AF_INET6, SOCK_DGRAM, 0);
+	if (!ASSERT_NEQ(sockfd, -1, "decrypt socket"))
+		goto fail;
+	err = sendto(sockfd, afalg_dst, sizeof(afalg_dst), 0, (void *)&addr, addrlen);
+	close(sockfd);
+	if (!ASSERT_EQ(err, sizeof(afalg_dst), "decrypt send"))
+		goto fail;
+
+	do_crypt_afalg(afalg_dst, afalg_plain, sizeof(afalg_plain), false);
+
+	if (!ASSERT_OK(skel->bss->status, "decrypt status"))
+		goto fail;
+	if (!ASSERT_STRNEQ(skel->bss->dst, afalg_plain, sizeof(afalg_plain), "decrypt AF_ALG"))
+		goto fail;
+
+	tc_attach_dec.flags = tc_attach_dec.prog_fd = tc_attach_dec.prog_id = 0;
+	err = bpf_tc_detach(&qdisc_hook, &tc_attach_dec);
+	ASSERT_OK(err, "bpf_tc_detach decrypt");
+
+fail:
+	close_netns(nstoken);
+	deinit_afalg();
+	SYS_NOFAIL("ip netns del " NS_TEST " &> /dev/null");
+	crypto_sanity__destroy(skel);
+}
diff --git a/tools/testing/selftests/bpf/progs/crypto_basic.c b/tools/testing/selftests/bpf/progs/crypto_basic.c
new file mode 100644
index 000000000000..8cf7168b42d5
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/crypto_basic.c
@@ -0,0 +1,68 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 Meta Platforms, Inc. and affiliates. */
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
+#include "bpf_misc.h"
+#include "bpf_kfuncs.h"
+#include "crypto_common.h"
+
+int status;
+SEC("syscall")
+int crypto_release(void *ctx)
+{
+	struct bpf_crypto_params params = {
+		.type = "skcipher",
+		.algo = "ecb(aes)",
+		.key_len = 16,
+	};
+
+	struct bpf_crypto_ctx *cctx;
+	int err = 0;
+
+	status = 0;
+
+	cctx = bpf_crypto_ctx_create(&params, sizeof(params), &err);
+
+	if (!cctx) {
+		status = err;
+		return 0;
+	}
+
+	bpf_crypto_ctx_release(cctx);
+
+	return 0;
+}
+
+SEC("syscall")
+__failure __msg("Unreleased reference")
+int crypto_acquire(void *ctx)
+{
+	struct bpf_crypto_params params = {
+		.type = "skcipher",
+		.algo = "ecb(aes)",
+		.key_len = 16,
+	};
+	struct bpf_crypto_ctx *cctx;
+	int err = 0;
+
+	status = 0;
+
+	cctx = bpf_crypto_ctx_create(&params, sizeof(params), &err);
+
+	if (!cctx) {
+		status = err;
+		return 0;
+	}
+
+	cctx = bpf_crypto_ctx_acquire(cctx);
+	if (!cctx)
+		return -EINVAL;
+
+	bpf_crypto_ctx_release(cctx);
+
+	return 0;
+}
+
+char __license[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/crypto_common.h b/tools/testing/selftests/bpf/progs/crypto_common.h
new file mode 100644
index 000000000000..df75dac19c37
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/crypto_common.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
+
+#ifndef _CRYPTO_COMMON_H
+#define _CRYPTO_COMMON_H
+
+#include "errno.h"
+#include <stdbool.h>
+
+struct bpf_crypto_ctx *bpf_crypto_ctx_create(const struct bpf_crypto_params *params,
+					     u32 params__sz, int *err) __ksym;
+struct bpf_crypto_ctx *bpf_crypto_ctx_acquire(struct bpf_crypto_ctx *ctx) __ksym;
+void bpf_crypto_ctx_release(struct bpf_crypto_ctx *ctx) __ksym;
+int bpf_crypto_encrypt(struct bpf_crypto_ctx *ctx, const struct bpf_dynptr *src,
+		       struct bpf_dynptr *dst, struct bpf_dynptr *iv) __ksym;
+int bpf_crypto_decrypt(struct bpf_crypto_ctx *ctx, const struct bpf_dynptr *src,
+		       struct bpf_dynptr *dst, struct bpf_dynptr *iv) __ksym;
+
+struct __crypto_ctx_value {
+	struct bpf_crypto_ctx __kptr * ctx;
+};
+
+struct array_map {
+	__uint(type, BPF_MAP_TYPE_ARRAY);
+	__type(key, int);
+	__type(value, struct __crypto_ctx_value);
+	__uint(max_entries, 1);
+} __crypto_ctx_map SEC(".maps");
+
+static inline struct __crypto_ctx_value *crypto_ctx_value_lookup(void)
+{
+	u32 key = 0;
+
+	return bpf_map_lookup_elem(&__crypto_ctx_map, &key);
+}
+
+static inline int crypto_ctx_insert(struct bpf_crypto_ctx *ctx)
+{
+	struct __crypto_ctx_value local, *v;
+	struct bpf_crypto_ctx *old;
+	u32 key = 0;
+	int err;
+
+	local.ctx = NULL;
+	err = bpf_map_update_elem(&__crypto_ctx_map, &key, &local, 0);
+	if (err) {
+		bpf_crypto_ctx_release(ctx);
+		return err;
+	}
+
+	v = bpf_map_lookup_elem(&__crypto_ctx_map, &key);
+	if (!v) {
+		bpf_crypto_ctx_release(ctx);
+		return -ENOENT;
+	}
+
+	old = bpf_kptr_xchg(&v->ctx, ctx);
+	if (old) {
+		bpf_crypto_ctx_release(old);
+		return -EEXIST;
+	}
+
+	return 0;
+}
+
+#endif /* _CRYPTO_COMMON_H */
diff --git a/tools/testing/selftests/bpf/progs/crypto_sanity.c b/tools/testing/selftests/bpf/progs/crypto_sanity.c
new file mode 100644
index 000000000000..1e3d866121f8
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/crypto_sanity.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
+
+#include "vmlinux.h"
+#include "bpf_tracing_net.h"
+#include <bpf/bpf_helpers.h>
+#include <bpf/bpf_endian.h>
+#include <bpf/bpf_tracing.h>
+#include "bpf_misc.h"
+#include "bpf_kfuncs.h"
+#include "crypto_common.h"
+
+unsigned char key[256] = {};
+u16 udp_test_port = 7777;
+u32 authsize, key_len;
+char algo[128] = {};
+char dst[16] = {};
+int status;
+
+static int skb_dynptr_validate(struct __sk_buff *skb, struct bpf_dynptr *psrc)
+{
+	struct ipv6hdr ip6h;
+	struct udphdr udph;
+	u32 offset;
+
+	if (skb->protocol != __bpf_constant_htons(ETH_P_IPV6))
+		return -1;
+
+	if (bpf_skb_load_bytes(skb, ETH_HLEN, &ip6h, sizeof(ip6h)))
+		return -1;
+
+	if (ip6h.nexthdr != IPPROTO_UDP)
+		return -1;
+
+	if (bpf_skb_load_bytes(skb, ETH_HLEN + sizeof(ip6h), &udph, sizeof(udph)))
+		return -1;
+
+	if (udph.dest != __bpf_htons(udp_test_port))
+		return -1;
+
+	offset = ETH_HLEN + sizeof(ip6h) + sizeof(udph);
+	if (skb->len < offset + 16)
+		return -1;
+
+	/* let's make sure that 16 bytes of payload are in the linear part of skb */
+	bpf_skb_pull_data(skb, offset + 16);
+	bpf_dynptr_from_skb(skb, 0, psrc);
+	bpf_dynptr_adjust(psrc, offset, offset + 16);
+
+	return 0;
+}
+
+SEC("syscall")
+int skb_crypto_setup(void *ctx)
+{
+	struct bpf_crypto_params params = {
+		.type = "skcipher",
+		.key_len = key_len,
+		.authsize = authsize,
+	};
+	struct bpf_crypto_ctx *cctx;
+	int err = 0;
+
+	status = 0;
+
+	if (key_len > 256) {
+		status = -EINVAL;
+		return 0;
+	}
+
+	__builtin_memcpy(&params.algo, algo, sizeof(algo));
+	__builtin_memcpy(&params.key, key, sizeof(key));
+	cctx = bpf_crypto_ctx_create(&params, sizeof(params), &err);
+
+	if (!cctx) {
+		status = err;
+		return 0;
+	}
+
+	err = crypto_ctx_insert(cctx);
+	if (err && err != -EEXIST)
+		status = err;
+
+	return 0;
+}
+
+SEC("tc")
+int decrypt_sanity(struct __sk_buff *skb)
+{
+	struct __crypto_ctx_value *v;
+	struct bpf_crypto_ctx *ctx;
+	struct bpf_dynptr psrc, pdst, iv;
+	int err;
+
+	err = skb_dynptr_validate(skb, &psrc);
+	if (err < 0) {
+		status = err;
+		return TC_ACT_SHOT;
+	}
+
+	v = crypto_ctx_value_lookup();
+	if (!v) {
+		status = -ENOENT;
+		return TC_ACT_SHOT;
+	}
+
+	ctx = v->ctx;
+	if (!ctx) {
+		status = -ENOENT;
+		return TC_ACT_SHOT;
+	}
+
+	/* dst is a global variable to make testing part easier to check. In real
+	 * production code it's better to use percpu map to get more performance.
+	 */
+	bpf_dynptr_from_mem(dst, sizeof(dst), 0, &pdst);
+	/* iv dynptr has to be initialized with 0 size, but proper memory region
+	 * has to be provided anyway
+	 */
+	bpf_dynptr_from_mem(dst, 0, 0, &iv);
+
+	status = bpf_crypto_decrypt(ctx, &psrc, &pdst, &iv);
+
+	return TC_ACT_SHOT;
+}
+
+SEC("tc")
+int encrypt_sanity(struct __sk_buff *skb)
+{
+	struct __crypto_ctx_value *v;
+	struct bpf_crypto_ctx *ctx;
+	struct bpf_dynptr psrc, pdst, iv;
+	int err;
+
+	status = 0;
+
+	err = skb_dynptr_validate(skb, &psrc);
+	if (err < 0) {
+		status = err;
+		return TC_ACT_SHOT;
+	}
+
+	v = crypto_ctx_value_lookup();
+	if (!v) {
+		status = -ENOENT;
+		return TC_ACT_SHOT;
+	}
+
+	ctx = v->ctx;
+	if (!ctx) {
+		status = -ENOENT;
+		return TC_ACT_SHOT;
+	}
+
+	/* dst is a global variable to make testing part easier to check. In real
+	 * production code it's better to use percpu map to get more performance.
+	 */
+	bpf_dynptr_from_mem(dst, sizeof(dst), 0, &pdst);
+	/* iv dynptr has to be initialized with 0 size, but proper memory region
+	 * has to be provided anyway
+	 */
+	bpf_dynptr_from_mem(dst, 0, 0, &iv);
+
+	status = bpf_crypto_encrypt(ctx, &psrc, &pdst, &iv);
+
+	return TC_ACT_SHOT;
+}
+
+char __license[] SEC("license") = "GPL";
-- 
2.43.0

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