On 12/1/23 5:06 PM, Vadim Fedorenko wrote:
Add simple tc hook selftests to show the way to work with new crypto
BPF API. Some weird structre and map are added to setup program to make
verifier happy about dynptr initialization from memory. Simple AES-ECB
algo is used to demonstrate encryption and decryption of fixed size
buffers.
Signed-off-by: Vadim Fedorenko <vadfed@xxxxxxxx>
---
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 | 215 ++++++++++++++++++
.../selftests/bpf/progs/crypto_common.h | 67 ++++++
.../selftests/bpf/progs/crypto_sanity.c | 192 ++++++++++++++++
4 files changed, 479 insertions(+)
create mode 100644 tools/testing/selftests/bpf/prog_tests/crypto_sanity.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 c125c441abc7..2221994a36d6 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..2dd73cb248be
--- /dev/null
+++ b/tools/testing/selftests/bpf/prog_tests/crypto_sanity.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 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"
+
+#define NS_TEST "crypto_sanity_ns"
+#define IPV6_IFACE_ADDR "face::1"
+#define UDP_TEST_PORT 7777
+static const unsigned char crypto_key[] = "testtest12345678";
+static const char plain_text[] = "stringtoencrypt0";
+static int opfd, tfmfd;
nit. init to -1 and test for -1.
+
+int init_afalg(void)
static
+{
+ 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;
+}
+
+void deinit_afalg(void)
static
+{
+ if (tfmfd)
+ close(tfmfd);
+ if (opfd)
+ close(opfd);
+}
+
+void do_crypt_afalg(const void *src, void *dst, int size, bool encrypt)
static
+{
+ 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_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,
+ .repeat = 1,
+ );
+ 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;
+
+ skel = crypto_sanity__open();
+ if (!ASSERT_OK_PTR(skel, "skel open"))
+ return;
+
+ bpf_program__set_autoload(skel->progs.crypto_accuire, true);
+
+ err = crypto_sanity__load(skel);
+ if (!ASSERT_ERR(err, "crypto_accuire unexpected load success"))
+ goto fail;
+
+ crypto_sanity__destroy(skel);
+
+ skel = crypto_sanity__open();
+ if (!ASSERT_OK_PTR(skel, "skel open"))
+ return;
+
+ bpf_program__set_autoload(skel->progs.crypto_accuire, false);
Is it needed?
+
+ 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);
+
+ err = crypto_sanity__load(skel);
+ if (!ASSERT_OK(err, "crypto_sanity__load"))
+ goto fail;
+
+ 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;
+
+ err = crypto_sanity__attach(skel);
+ if (!ASSERT_OK(err, "crypto_sanity__attach"))
+ goto fail;
+
+ pfd = bpf_program__fd(skel->progs.crypto_release);
+ if (!ASSERT_GT(pfd, 0, "crypto_release fd"))
+ goto fail;
+
+ err = bpf_prog_test_run_opts(pfd, &opts);
+ if (!ASSERT_OK(err, "crypto_release") ||
+ !ASSERT_OK(opts.retval, "crypto_release retval"))
+ goto fail;
+
+ 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, 16, 0, (void *)&addr, addrlen);
+ close(sockfd);
+ if (!ASSERT_EQ(err, 16, "encrypt send"))
+ goto fail;
+
+ do_crypt_afalg(plain_text, afalg_dst, 16, true);
+
+ bpf_tc_detach(&qdisc_hook, &tc_attach_enc);
+ if (!ASSERT_OK(skel->bss->status, "encrypt status"))
+ goto fail;
+ if (!ASSERT_STRNEQ(skel->bss->dst, afalg_dst, sizeof(afalg_dst), "encrypt AF_ALG"))
nit. Please replace all numeric value "16" usages in this patch with sizeof() or
a macro.
+ 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, 16, 0, (void *)&addr, addrlen);
+ close(sockfd);
+ if (!ASSERT_EQ(err, 16, "decrypt send"))
+ goto fail;
+
+ do_crypt_afalg(afalg_dst, afalg_plain, 16, false);
+
+ bpf_tc_detach(&qdisc_hook, &tc_attach_dec);
+ 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;
+
+fail:
+ if (nstoken) {
+ bpf_tc_hook_destroy(&qdisc_hook);
+ 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_sanity.c b/tools/testing/selftests/bpf/progs/crypto_sanity.c
new file mode 100644
index 000000000000..f566ff189b7e
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/crypto_sanity.c
@@ -0,0 +1,192 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright (c) 2023 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"
+
+#define UDP_TEST_PORT 7777
+unsigned char crypto_key[16] = "testtest12345678";
nit. Initialize the crypto_key from the prog_tests/crypto_sanity.c through
skel->bss->crypto_key.
+char dst[32] = {};
Please add comment on why 32 is needed instead of 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_constant_htons(UDP_TEST_PORT))
+ return -1;
+
+ offset = ETH_HLEN + sizeof(ip6h) + sizeof(udph);
+ if (skb->len < offset + 16)
+ return -1;
+
+ bpf_dynptr_from_skb(skb, 0, psrc);
+ bpf_dynptr_adjust(psrc, offset, offset + 16);
The bpf_crypto_(de|en)crypt kfunc requires the 16 bytes to be in the linear area
of psrc, so it is better to do a bpf_skb_pull_data() if it is not in the linear
area. People will directly borrow the code from here.
+
+ return 0;
+}
+
+SEC("fentry.s/bpf_fentry_test1")
+int BPF_PROG(skb_crypto_setup)
+{
+ struct bpf_crypto_ctx *cctx;
+ struct bpf_dynptr key = {};
+ int err = 0;
+
+ status = 0;
+
+ bpf_dynptr_from_mem(crypto_key, sizeof(crypto_key), 0, &key);
+ cctx = bpf_crypto_ctx_create("skcipher", "ecb(aes)", &key, 0, &err);
+
+ if (!cctx) {
+ status = err;
+ return 0;
+ }
+
+ err = crypto_ctx_insert(cctx);
+ if (err && err != -EEXIST)
+ status = err;
+
+ return 0;
+}
+
+SEC("fentry.s/bpf_fentry_test1")
+int BPF_PROG(crypto_release)
+{
+ struct bpf_crypto_ctx *cctx;
+ struct bpf_dynptr key = {};
+ int err = 0;
+
+ status = 0;
+
+ bpf_dynptr_from_mem(crypto_key, sizeof(crypto_key), 0, &key);
+ cctx = bpf_crypto_ctx_create("skcipher", "ecb(aes)", &key, 0, &err);
+
+ if (!cctx) {
+ status = err;
+ return 0;
+ }
+
+ bpf_crypto_ctx_release(cctx);
+
+ return 0;
+}
+
+SEC("?fentry.s/bpf_fentry_test1")
+__failure __msg("Unreleased reference")
+int BPF_PROG(crypto_accuire)
Does it mean to be s/accuire/acquire/ ?
+{
+ struct bpf_crypto_ctx *cctx;
+ struct bpf_dynptr key = {};
+ int err = 0;
+
+ status = 0;
+
+ bpf_dynptr_from_mem(crypto_key, sizeof(crypto_key), 0, &key);
+ cctx = bpf_crypto_ctx_create("skcipher", "ecb(aes)", &key, 0, &err);
+
+ if (!cctx) {
+ status = err;
+ return 0;
+ }
+
+ cctx = bpf_crypto_ctx_acquire(cctx);
+ if (!cctx)
+ return -EINVAL;
+
+ bpf_crypto_ctx_release(cctx);
+
+ 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;
+ }
+
+ bpf_dynptr_from_mem(dst, sizeof(dst), 0, &pdst);
+ bpf_dynptr_from_mem(dst, 0, 0, &iv);
This is quite non-intutive to say iv is not needed. A better user experience is
to allow passing NULL to the kfunc. This probably could be improved in the
future without breaking the kfunc api. Please add a comment here.
+
+ 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;
+ }
+
+ bpf_dynptr_from_mem(dst, sizeof(dst), 0, &pdst);
+ 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";
