Add a kTLS TX regression test for the BPF sk_msg apply_bytes split-record path. The test sends four 4096-byte writes through a sockmap verdict program that applies 512-byte verdict windows, then verifies that the peer receives the full TLS-protected stream.
Run the case once with the synchronous provider and once after instantiating an async pcrypt gcm(aes) provider. Vulnerable kernels silently truncate the async run because the split open-record remainder is lost when encryption returns -EINPROGRESS. Signed-off-by: Christopher Lusk <[email protected]> Assisted-by: Codex:gpt-5.5 Assisted-by: Claude:claude-opus-4-7 --- tools/testing/selftests/net/Makefile | 5 + .../selftests/net/ktls_async_split.bpf.c | 24 ++ .../testing/selftests/net/ktls_async_split.c | 391 ++++++++++++++++++ 3 files changed, 420 insertions(+) create mode 100644 tools/testing/selftests/net/ktls_async_split.bpf.c create mode 100644 tools/testing/selftests/net/ktls_async_split.c diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile index f3da38c54..0435327e9 100644 --- a/tools/testing/selftests/net/Makefile +++ b/tools/testing/selftests/net/Makefile @@ -179,6 +179,7 @@ TEST_GEN_PROGS := \ epoll_busy_poll \ icmp_rfc4884 \ ipv6_fragmentation \ + ktls_async_split \ proc_net_pktgen \ reuseaddr_conflict \ reuseport_bpf \ @@ -236,3 +237,7 @@ $(OUTPUT)/bind_bhash: LDLIBS += -lpthread $(OUTPUT)/io_uring_zerocopy_tx: CFLAGS += -I../../../include/ include bpf.mk + +$(OUTPUT)/ktls_async_split: CFLAGS += -I../../../lib +$(OUTPUT)/ktls_async_split: LDLIBS += $(BPFOBJ) -lelf -lz +$(OUTPUT)/ktls_async_split: $(BPFOBJ) diff --git a/tools/testing/selftests/net/ktls_async_split.bpf.c b/tools/testing/selftests/net/ktls_async_split.bpf.c new file mode 100644 index 000000000..c7caafb73 --- /dev/null +++ b/tools/testing/selftests/net/ktls_async_split.bpf.c @@ -0,0 +1,24 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/bpf.h> +#include <bpf/bpf_helpers.h> + +#ifndef SK_PASS +#define SK_PASS 1 +#endif + +char LICENSE[] SEC("license") = "GPL"; + +struct { + __uint(type, BPF_MAP_TYPE_SOCKMAP); + __uint(max_entries, 4); + __type(key, __u32); + __type(value, int); +} sock_map SEC(".maps"); + +SEC("sk_msg") +int apply_bytes_verdict(struct sk_msg_md *msg) +{ + bpf_msg_apply_bytes(msg, 512); + return SK_PASS; +} diff --git a/tools/testing/selftests/net/ktls_async_split.c b/tools/testing/selftests/net/ktls_async_split.c new file mode 100644 index 000000000..a9a84e0f5 --- /dev/null +++ b/tools/testing/selftests/net/ktls_async_split.c @@ -0,0 +1,391 @@ +// SPDX-License-Identifier: GPL-2.0 + +#define _GNU_SOURCE + +#include <arpa/inet.h> +#include <bpf/bpf.h> +#include <bpf/libbpf.h> +#include <errno.h> +#include <fcntl.h> +#include <linux/if_alg.h> +#include <linux/bpf.h> +#include <linux/tls.h> +#include <netinet/in.h> +#include <netinet/tcp.h> +#include <signal.h> +#include <stdbool.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/resource.h> +#include <sys/socket.h> +#include <sys/types.h> +#include <sys/wait.h> +#include <unistd.h> + +#include "kselftest.h" + +#ifndef SOL_TLS +#define SOL_TLS 282 +#endif + +#define EXPECTED_BYTES 17312 + +static void fill_seq(unsigned char *p, size_t n, unsigned char seed) +{ + size_t i; + + for (i = 0; i < n; i++) + p[i] = (unsigned char)(seed + i); +} + +static void bump_memlock(void) +{ + struct rlimit r = { RLIM_INFINITY, RLIM_INFINITY }; + + setrlimit(RLIMIT_MEMLOCK, &r); +} + +static int run_cmd(const char *cmd) +{ + int ret = system(cmd); + + if (ret == -1) + return -1; + if (WIFEXITED(ret)) + return WEXITSTATUS(ret); + return 1; +} + +static int instantiate_aead(const char *name) +{ + struct sockaddr_alg sa = { + .salg_family = AF_ALG, + }; + int fd, ret; + + strncpy((char *)sa.salg_type, "aead", sizeof(sa.salg_type) - 1); + strncpy((char *)sa.salg_name, name, sizeof(sa.salg_name) - 1); + + fd = socket(AF_ALG, SOCK_SEQPACKET, 0); + if (fd < 0) + return -errno; + + ret = bind(fd, (struct sockaddr *)&sa, sizeof(sa)); + if (ret < 0) + ret = -errno; + + close(fd); + return ret; +} + +static bool have_async_pcrypt(void) +{ + FILE *f = fopen("/proc/crypto", "r"); + char line[256]; + bool in_driver = false; + bool async = false; + + if (!f) + return false; + + while (fgets(line, sizeof(line), f)) { + if (!strncmp(line, "driver", 6)) { + in_driver = strstr(line, "pcrypt(") && + strstr(line, "gcm"); + async = false; + continue; + } + if (in_driver && !strncmp(line, "async", 5)) { + async = strstr(line, "yes"); + if (async) { + fclose(f); + return true; + } + } + } + + fclose(f); + return false; +} + +static bool module_loaded(const char *name) +{ + FILE *f = fopen("/proc/modules", "r"); + char line[256], mod[128]; + + if (!f) + return false; + + while (fgets(line, sizeof(line), f)) { + if (sscanf(line, "%127s", mod) == 1 && !strcmp(mod, name)) { + fclose(f); + return true; + } + } + + fclose(f); + return false; +} + +static int make_listener(unsigned short *port) +{ + struct sockaddr_in addr = { + .sin_family = AF_INET, + .sin_addr.s_addr = htonl(INADDR_LOOPBACK), + .sin_port = 0, + }; + socklen_t len = sizeof(addr); + int fd, one = 1; + + fd = socket(AF_INET, SOCK_STREAM, 0); + if (fd < 0) + return -errno; + + if (setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)) < 0) + goto err; + if (bind(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) + goto err; + if (listen(fd, 1) < 0) + goto err; + if (getsockname(fd, (struct sockaddr *)&addr, &len) < 0) + goto err; + + *port = ntohs(addr.sin_port); + return fd; + +err: + close(fd); + return -errno; +} + +static int connect_client(unsigned short port) +{ + struct sockaddr_in addr = { + .sin_family = AF_INET, + .sin_addr.s_addr = htonl(INADDR_LOOPBACK), + .sin_port = htons(port), + }; + int fd; + + fd = socket(AF_INET, SOCK_STREAM, 0); + if (fd < 0) + return -errno; + if (connect(fd, (struct sockaddr *)&addr, sizeof(addr)) < 0) { + close(fd); + return -errno; + } + + return fd; +} + +static int make_tcp_pair(int *client_fd, int *peer_fd) +{ + unsigned short port = 0; + int listen_fd, c, p; + + listen_fd = make_listener(&port); + if (listen_fd < 0) + return listen_fd; + + c = connect_client(port); + if (c < 0) { + close(listen_fd); + return c; + } + + p = accept(listen_fd, NULL, NULL); + close(listen_fd); + if (p < 0) { + close(c); + return -errno; + } + + *client_fd = c; + *peer_fd = p; + return 0; +} + +static int enable_ktls_tx(int fd) +{ + struct tls12_crypto_info_aes_gcm_128 info; + static const char ulp[] = "tls"; + + if (setsockopt(fd, IPPROTO_TCP, TCP_ULP, ulp, sizeof(ulp)) < 0) + return -errno; + + memset(&info, 0, sizeof(info)); + info.info.version = TLS_1_2_VERSION; + info.info.cipher_type = TLS_CIPHER_AES_GCM_128; + fill_seq(info.iv, sizeof(info.iv), 0x11); + fill_seq(info.key, sizeof(info.key), 0x22); + fill_seq(info.salt, sizeof(info.salt), 0x33); + fill_seq(info.rec_seq, sizeof(info.rec_seq), 0x44); + + if (setsockopt(fd, SOL_TLS, TLS_TX, &info, sizeof(info)) < 0) + return -errno; + + return 0; +} + +static int attach_bpf(const char *obj_path, int sock_fd, struct bpf_object **obj_out) +{ + struct bpf_object *obj; + struct bpf_program *prog; + int map_fd, prog_fd; + __u32 key = 0; + + obj = bpf_object__open_file(obj_path, NULL); + if (libbpf_get_error(obj)) + return -EINVAL; + if (bpf_object__load(obj)) + return -EINVAL; + + prog = bpf_object__find_program_by_name(obj, "apply_bytes_verdict"); + if (!prog) + return -ENOENT; + prog_fd = bpf_program__fd(prog); + + map_fd = bpf_object__find_map_fd_by_name(obj, "sock_map"); + if (map_fd < 0) + return -ENOENT; + + if (bpf_prog_attach(prog_fd, map_fd, BPF_SK_MSG_VERDICT, 0)) + return -errno; + if (bpf_map_update_elem(map_fd, &key, &sock_fd, BPF_ANY)) + return -errno; + + *obj_out = obj; + return 0; +} + +static void server_loop(int fd, int out_fd) +{ + unsigned char buf[16384]; + int total = 0; + + for (;;) { + ssize_t n = read(fd, buf, sizeof(buf)); + + if (n < 0) { + if (errno == EINTR) + continue; + _exit(1); + } + if (!n) + break; + total += (int)n; + } + + (void)write(out_fd, &total, sizeof(total)); + close(fd); + close(out_fd); + _exit(0); +} + +static int run_case(const char *obj_path, int *server_read) +{ + struct bpf_object *obj = NULL; + unsigned char buf[4096]; + int client_fd = -1, peer_fd = -1, pipefd[2] = { -1, -1 }; + pid_t pid; + int status, ret, i; + ssize_t n, got; + + ret = make_tcp_pair(&client_fd, &peer_fd); + if (ret) + return ret; + if (pipe(pipefd)) { + close(client_fd); + close(peer_fd); + return -errno; + } + + pid = fork(); + if (pid < 0) { + close(client_fd); + close(peer_fd); + close(pipefd[0]); + close(pipefd[1]); + return -errno; + } + if (!pid) { + close(pipefd[0]); + server_loop(peer_fd, pipefd[1]); + } + + close(peer_fd); + close(pipefd[1]); + + ret = attach_bpf(obj_path, client_fd, &obj); + if (ret) + goto out; + ret = enable_ktls_tx(client_fd); + if (ret) + goto out; + + fill_seq(buf, sizeof(buf), 0x80); + for (i = 0; i < 4; i++) { + n = send(client_fd, buf, sizeof(buf), 0); + if (n != sizeof(buf)) { + ret = n < 0 ? -errno : -EIO; + goto out; + } + } + + shutdown(client_fd, SHUT_WR); + got = read(pipefd[0], server_read, sizeof(*server_read)); + if (got != sizeof(*server_read)) + ret = -EIO; + +out: + close(client_fd); + close(pipefd[0]); + if (obj) + bpf_object__close(obj); + if (waitpid(pid, &status, 0) < 0) + return -errno; + if (!ret && (!WIFEXITED(status) || WEXITSTATUS(status))) + ret = -EIO; + return ret; +} + +int main(int argc, char **argv) +{ + const char *obj_path = argc > 1 ? argv[1] : "./ktls_async_split.bpf.o"; + int sync_read = 0, async_read = 0, ret; + + ksft_print_header(); + ksft_set_plan(2); + bump_memlock(); + + if (run_cmd("modprobe tls >/dev/null 2>&1") && !module_loaded("tls")) + ksft_exit_skip("missing tls module\n"); + + /* Keep the first run on the synchronous provider. */ + run_cmd("modprobe -r pcrypt >/dev/null 2>&1"); + ret = run_case(obj_path, &sync_read); + if (ret) + ksft_exit_fail_msg("sync case failed: %s\n", strerror(-ret)); + if (sync_read != EXPECTED_BYTES) + ksft_exit_fail_msg("sync case read %d, expected %d\n", + sync_read, EXPECTED_BYTES); + ksft_test_result_pass("sync provider transmits split record\n"); + + run_cmd("modprobe af_alg algif_aead pcrypt >/dev/null 2>&1"); + ret = instantiate_aead("pcrypt(generic-gcm-vaes-avx2)"); + if (ret) + ret = instantiate_aead("pcrypt(gcm(aes))"); + if (ret || !have_async_pcrypt()) + ksft_exit_skip("missing async pcrypt gcm(aes) provider\n"); + + ret = run_case(obj_path, &async_read); + if (ret) + ksft_exit_fail_msg("async case failed: %s\n", strerror(-ret)); + if (async_read != EXPECTED_BYTES) + ksft_exit_fail_msg("async case read %d, expected %d\n", + async_read, EXPECTED_BYTES); + ksft_test_result_pass("async provider transmits split record\n"); + + ksft_finished(); +} -- 2.54.0
