selftests: tls: add selftests for TLS sockets

Add selftests for tls socket.  Tests various iov and message options,
poll blocking and nonblocking behavior, partial message sends / receives,
 and control message data.  Tests should pass regardless of if TLS
is enabled in the kernel or not, and print a warning message if not.
Signed-off-by: NDave Watson <davejwatson@fb.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tools/testing/selftests/net/Makefile

@@ -13,7 +13,7 @@ TEST_GEN_FILES += psock_fanout psock_tpacket msg_zerocopy
 TEST_GEN_FILES += tcp_mmap tcp_inq psock_snd
 TEST_GEN_FILES += udpgso udpgso_bench_tx udpgso_bench_rx
 TEST_GEN_PROGS = reuseport_bpf reuseport_bpf_cpu reuseport_bpf_numa
-TEST_GEN_PROGS += reuseport_dualstack reuseaddr_conflict
+TEST_GEN_PROGS += reuseport_dualstack reuseaddr_conflict tls
 
 include ../lib.mk
 

tools/testing/selftests/net/tls.c

+// SPDX-License-Identifier: GPL-2.0
+
+#define _GNU_SOURCE
+
+#include <arpa/inet.h>
+#include <errno.h>
+#include <error.h>
+#include <fcntl.h>
+#include <poll.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <linux/tls.h>
+#include <linux/tcp.h>
+#include <linux/socket.h>
+
+#include <sys/types.h>
+#include <sys/sendfile.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+
+#include "../kselftest_harness.h"
+
+#define TLS_PAYLOAD_MAX_LEN 16384
+#define SOL_TLS 282
+
+FIXTURE(tls)
+{
+	int fd, cfd;
+	bool notls;
+};
+
+FIXTURE_SETUP(tls)
+{
+	struct tls12_crypto_info_aes_gcm_128 tls12;
+	struct sockaddr_in addr;
+	socklen_t len;
+	int sfd, ret;
+
+	self->notls = false;
+	len = sizeof(addr);
+
+	memset(&tls12, 0, sizeof(tls12));
+	tls12.info.version = TLS_1_2_VERSION;
+	tls12.info.cipher_type = TLS_CIPHER_AES_GCM_128;
+
+	addr.sin_family = AF_INET;
+	addr.sin_addr.s_addr = htonl(INADDR_ANY);
+	addr.sin_port = 0;
+
+	self->fd = socket(AF_INET, SOCK_STREAM, 0);
+	sfd = socket(AF_INET, SOCK_STREAM, 0);
+
+	ret = bind(sfd, &addr, sizeof(addr));
+	ASSERT_EQ(ret, 0);
+	ret = listen(sfd, 10);
+	ASSERT_EQ(ret, 0);
+
+	ret = getsockname(sfd, &addr, &len);
+	ASSERT_EQ(ret, 0);
+
+	ret = connect(self->fd, &addr, sizeof(addr));
+	ASSERT_EQ(ret, 0);
+
+	ret = setsockopt(self->fd, IPPROTO_TCP, TCP_ULP, "tls", sizeof("tls"));
+	if (ret != 0) {
+		self->notls = true;
+		printf("Failure setting TCP_ULP, testing without tls\n");
+	}
+
+	if (!self->notls) {
+		ret = setsockopt(self->fd, SOL_TLS, TLS_TX, &tls12,
+				 sizeof(tls12));
+		ASSERT_EQ(ret, 0);
+	}
+
+	self->cfd = accept(sfd, &addr, &len);
+	ASSERT_GE(self->cfd, 0);
+
+	if (!self->notls) {
+		ret = setsockopt(self->cfd, IPPROTO_TCP, TCP_ULP, "tls",
+				 sizeof("tls"));
+		ASSERT_EQ(ret, 0);
+
+		ret = setsockopt(self->cfd, SOL_TLS, TLS_RX, &tls12,
+				 sizeof(tls12));
+		ASSERT_EQ(ret, 0);
+	}
+
+	close(sfd);
+}
+
+FIXTURE_TEARDOWN(tls)
+{
+	close(self->fd);
+	close(self->cfd);
+}
+
+TEST_F(tls, sendfile)
+{
+	int filefd = open("/proc/self/exe", O_RDONLY);
+	struct stat st;
+
+	EXPECT_GE(filefd, 0);
+	fstat(filefd, &st);
+	EXPECT_GE(sendfile(self->fd, filefd, 0, st.st_size), 0);
+}
+
+TEST_F(tls, send_then_sendfile)
+{
+	int filefd = open("/proc/self/exe", O_RDONLY);
+	char const *test_str = "test_send";
+	int to_send = strlen(test_str) + 1;
+	char recv_buf[10];
+	struct stat st;
+	char *buf;
+
+	EXPECT_GE(filefd, 0);
+	fstat(filefd, &st);
+	buf = (char *)malloc(st.st_size);
+
+	EXPECT_EQ(send(self->fd, test_str, to_send, 0), to_send);
+	EXPECT_EQ(recv(self->cfd, recv_buf, to_send, 0), to_send);
+	EXPECT_EQ(memcmp(test_str, recv_buf, to_send), 0);
+
+	EXPECT_GE(sendfile(self->fd, filefd, 0, st.st_size), 0);
+	EXPECT_EQ(recv(self->cfd, buf, st.st_size, 0), st.st_size);
+}
+
+TEST_F(tls, recv_max)
+{
+	unsigned int send_len = TLS_PAYLOAD_MAX_LEN;
+	char recv_mem[TLS_PAYLOAD_MAX_LEN];
+	char buf[TLS_PAYLOAD_MAX_LEN];
+
+	EXPECT_GE(send(self->fd, buf, send_len, 0), 0);
+	EXPECT_NE(recv(self->cfd, recv_mem, send_len, 0), -1);
+	EXPECT_EQ(memcmp(buf, recv_mem, send_len), 0);
+}
+
+TEST_F(tls, recv_small)
+{
+	char const *test_str = "test_read";
+	int send_len = 10;
+	char buf[10];
+
+	send_len = strlen(test_str) + 1;
+	EXPECT_EQ(send(self->fd, test_str, send_len, 0), send_len);
+	EXPECT_NE(recv(self->cfd, buf, send_len, 0), -1);
+	EXPECT_EQ(memcmp(buf, test_str, send_len), 0);
+}
+
+TEST_F(tls, msg_more)
+{
+	char const *test_str = "test_read";
+	int send_len = 10;
+	char buf[10 * 2];
+
+	EXPECT_EQ(send(self->fd, test_str, send_len, MSG_MORE), send_len);
+	EXPECT_EQ(recv(self->cfd, buf, send_len, MSG_DONTWAIT), -1);
+	EXPECT_EQ(send(self->fd, test_str, send_len, 0), send_len);
+	EXPECT_EQ(recv(self->cfd, buf, send_len * 2, MSG_DONTWAIT),
+		  send_len * 2);
+	EXPECT_EQ(memcmp(buf, test_str, send_len), 0);
+}
+
+TEST_F(tls, sendmsg_single)
+{
+	struct msghdr msg;
+
+	char const *test_str = "test_sendmsg";
+	size_t send_len = 13;
+	struct iovec vec;
+	char buf[13];
+
+	vec.iov_base = (char *)test_str;
+	vec.iov_len = send_len;
+	memset(&msg, 0, sizeof(struct msghdr));
+	msg.msg_iov = &vec;
+	msg.msg_iovlen = 1;
+	EXPECT_EQ(sendmsg(self->fd, &msg, 0), send_len);
+	EXPECT_EQ(recv(self->cfd, buf, send_len, 0), send_len);
+	EXPECT_EQ(memcmp(buf, test_str, send_len), 0);
+}
+
+TEST_F(tls, sendmsg_large)
+{
+	void *mem = malloc(16384);
+	size_t send_len = 16384;
+	size_t sends = 128;
+	struct msghdr msg;
+	size_t recvs = 0;
+	size_t sent = 0;
+
+	memset(&msg, 0, sizeof(struct msghdr));
+	while (sent++ < sends) {
+		struct iovec vec = { (void *)mem, send_len };
+
+		msg.msg_iov = &vec;
+		msg.msg_iovlen = 1;
+		EXPECT_EQ(sendmsg(self->cfd, &msg, 0), send_len);
+	}
+
+	while (recvs++ < sends)
+		EXPECT_NE(recv(self->fd, mem, send_len, 0), -1);
+
+	free(mem);
+}
+
+TEST_F(tls, sendmsg_multiple)
+{
+	char const *test_str = "test_sendmsg_multiple";
+	struct iovec vec[5];
+	char *test_strs[5];
+	struct msghdr msg;
+	int total_len = 0;
+	int len_cmp = 0;
+	int iov_len = 5;
+	char *buf;
+	int i;
+
+	memset(&msg, 0, sizeof(struct msghdr));
+	for (i = 0; i < iov_len; i++) {
+		test_strs[i] = (char *)malloc(strlen(test_str) + 1);
+		snprintf(test_strs[i], strlen(test_str) + 1, "%s", test_str);
+		vec[i].iov_base = (void *)test_strs[i];
+		vec[i].iov_len = strlen(test_strs[i]) + 1;
+		total_len += vec[i].iov_len;
+	}
+	msg.msg_iov = vec;
+	msg.msg_iovlen = iov_len;
+
+	EXPECT_EQ(sendmsg(self->cfd, &msg, 0), total_len);
+	buf = malloc(total_len);
+	EXPECT_NE(recv(self->fd, buf, total_len, 0), -1);
+	for (i = 0; i < iov_len; i++) {
+		EXPECT_EQ(memcmp(test_strs[i], buf + len_cmp,
+				 strlen(test_strs[i])),
+			  0);
+		len_cmp += strlen(buf + len_cmp) + 1;
+	}
+	for (i = 0; i < iov_len; i++)
+		free(test_strs[i]);
+	free(buf);
+}
+
+TEST_F(tls, sendmsg_multiple_stress)
+{
+	char const *test_str = "abcdefghijklmno";
+	struct iovec vec[1024];
+	char *test_strs[1024];
+	int iov_len = 1024;
+	int total_len = 0;
+	char buf[1 << 14];
+	struct msghdr msg;
+	int len_cmp = 0;
+	int i;
+
+	memset(&msg, 0, sizeof(struct msghdr));
+	for (i = 0; i < iov_len; i++) {
+		test_strs[i] = (char *)malloc(strlen(test_str) + 1);
+		snprintf(test_strs[i], strlen(test_str) + 1, "%s", test_str);
+		vec[i].iov_base = (void *)test_strs[i];
+		vec[i].iov_len = strlen(test_strs[i]) + 1;
+		total_len += vec[i].iov_len;
+	}
+	msg.msg_iov = vec;
+	msg.msg_iovlen = iov_len;
+
+	EXPECT_EQ(sendmsg(self->fd, &msg, 0), total_len);
+	EXPECT_NE(recv(self->cfd, buf, total_len, 0), -1);
+
+	for (i = 0; i < iov_len; i++)
+		len_cmp += strlen(buf + len_cmp) + 1;
+
+	for (i = 0; i < iov_len; i++)
+		free(test_strs[i]);
+}
+
+TEST_F(tls, splice_from_pipe)
+{
+	int send_len = TLS_PAYLOAD_MAX_LEN;
+	char mem_send[TLS_PAYLOAD_MAX_LEN];
+	char mem_recv[TLS_PAYLOAD_MAX_LEN];
+	int p[2];
+
+	ASSERT_GE(pipe(p), 0);
+	EXPECT_GE(write(p[1], mem_send, send_len), 0);
+	EXPECT_GE(splice(p[0], NULL, self->fd, NULL, send_len, 0), 0);
+	EXPECT_GE(recv(self->cfd, mem_recv, send_len, 0), 0);
+	EXPECT_EQ(memcmp(mem_send, mem_recv, send_len), 0);
+}
+
+TEST_F(tls, splice_from_pipe2)
+{
+	int send_len = 16000;
+	char mem_send[16000];
+	char mem_recv[16000];
+	int p2[2];
+	int p[2];
+
+	ASSERT_GE(pipe(p), 0);
+	ASSERT_GE(pipe(p2), 0);
+	EXPECT_GE(write(p[1], mem_send, 8000), 0);
+	EXPECT_GE(splice(p[0], NULL, self->fd, NULL, 8000, 0), 0);
+	EXPECT_GE(write(p2[1], mem_send + 8000, 8000), 0);
+	EXPECT_GE(splice(p2[0], NULL, self->fd, NULL, 8000, 0), 0);
+	EXPECT_GE(recv(self->cfd, mem_recv, send_len, 0), 0);
+	EXPECT_EQ(memcmp(mem_send, mem_recv, send_len), 0);
+}
+
+TEST_F(tls, send_and_splice)
+{
+	int send_len = TLS_PAYLOAD_MAX_LEN;
+	char mem_send[TLS_PAYLOAD_MAX_LEN];
+	char mem_recv[TLS_PAYLOAD_MAX_LEN];
+	char const *test_str = "test_read";
+	int send_len2 = 10;
+	char buf[10];
+	int p[2];
+
+	ASSERT_GE(pipe(p), 0);
+	EXPECT_EQ(send(self->fd, test_str, send_len2, 0), send_len2);
+	EXPECT_NE(recv(self->cfd, buf, send_len2, 0), -1);
+	EXPECT_EQ(memcmp(test_str, buf, send_len2), 0);
+
+	EXPECT_GE(write(p[1], mem_send, send_len), send_len);
+	EXPECT_GE(splice(p[0], NULL, self->fd, NULL, send_len, 0), send_len);
+
+	EXPECT_GE(recv(self->cfd, mem_recv, send_len, 0), 0);
+	EXPECT_EQ(memcmp(mem_send, mem_recv, send_len), 0);
+}
+
+TEST_F(tls, splice_to_pipe)
+{
+	int send_len = TLS_PAYLOAD_MAX_LEN;
+	char mem_send[TLS_PAYLOAD_MAX_LEN];
+	char mem_recv[TLS_PAYLOAD_MAX_LEN];
+	int p[2];
+
+	ASSERT_GE(pipe(p), 0);
+	EXPECT_GE(send(self->fd, mem_send, send_len, 0), 0);
+	EXPECT_GE(splice(self->cfd, NULL, p[1], NULL, send_len, 0), 0);
+	EXPECT_GE(read(p[0], mem_recv, send_len), 0);
+	EXPECT_EQ(memcmp(mem_send, mem_recv, send_len), 0);
+}
+
+TEST_F(tls, recvmsg_single)
+{
+	char const *test_str = "test_recvmsg_single";
+	int send_len = strlen(test_str) + 1;
+	char buf[20];
+	struct msghdr hdr;
+	struct iovec vec;
+
+	memset(&hdr, 0, sizeof(hdr));
+	EXPECT_EQ(send(self->fd, test_str, send_len, 0), send_len);
+	vec.iov_base = (char *)buf;
+	vec.iov_len = send_len;
+	hdr.msg_iovlen = 1;
+	hdr.msg_iov = &vec;
+	EXPECT_NE(recvmsg(self->cfd, &hdr, 0), -1);
+	EXPECT_EQ(memcmp(test_str, buf, send_len), 0);
+}
+
+TEST_F(tls, recvmsg_single_max)
+{
+	int send_len = TLS_PAYLOAD_MAX_LEN;
+	char send_mem[TLS_PAYLOAD_MAX_LEN];
+	char recv_mem[TLS_PAYLOAD_MAX_LEN];
+	struct iovec vec;
+	struct msghdr hdr;
+
+	EXPECT_EQ(send(self->fd, send_mem, send_len, 0), send_len);
+	vec.iov_base = (char *)recv_mem;
+	vec.iov_len = TLS_PAYLOAD_MAX_LEN;
+
+	hdr.msg_iovlen = 1;
+	hdr.msg_iov = &vec;
+	EXPECT_NE(recvmsg(self->cfd, &hdr, 0), -1);
+	EXPECT_EQ(memcmp(send_mem, recv_mem, send_len), 0);
+}
+
+TEST_F(tls, recvmsg_multiple)
+{
+	unsigned int msg_iovlen = 1024;
+	unsigned int len_compared = 0;
+	struct iovec vec[1024];
+	char *iov_base[1024];
+	unsigned int iov_len = 16;
+	int send_len = 1 << 14;
+	char buf[1 << 14];
+	struct msghdr hdr;
+	int i;
+
+	EXPECT_EQ(send(self->fd, buf, send_len, 0), send_len);
+	for (i = 0; i < msg_iovlen; i++) {
+		iov_base[i] = (char *)malloc(iov_len);
+		vec[i].iov_base = iov_base[i];
+		vec[i].iov_len = iov_len;
+	}
+
+	hdr.msg_iovlen = msg_iovlen;
+	hdr.msg_iov = vec;
+	EXPECT_NE(recvmsg(self->cfd, &hdr, 0), -1);
+	for (i = 0; i < msg_iovlen; i++)
+		len_compared += iov_len;
+
+	for (i = 0; i < msg_iovlen; i++)
+		free(iov_base[i]);
+}
+
+TEST_F(tls, single_send_multiple_recv)
+{
+	unsigned int total_len = TLS_PAYLOAD_MAX_LEN * 2;
+	unsigned int send_len = TLS_PAYLOAD_MAX_LEN;
+	char send_mem[TLS_PAYLOAD_MAX_LEN * 2];
+	char recv_mem[TLS_PAYLOAD_MAX_LEN * 2];
+
+	EXPECT_GE(send(self->fd, send_mem, total_len, 0), 0);
+	memset(recv_mem, 0, total_len);
+
+	EXPECT_NE(recv(self->cfd, recv_mem, send_len, 0), -1);
+	EXPECT_NE(recv(self->cfd, recv_mem + send_len, send_len, 0), -1);
+	EXPECT_EQ(memcmp(send_mem, recv_mem, total_len), 0);
+}
+
+TEST_F(tls, multiple_send_single_recv)
+{
+	unsigned int total_len = 2 * 10;
+	unsigned int send_len = 10;
+	char recv_mem[2 * 10];
+	char send_mem[10];
+
+	EXPECT_GE(send(self->fd, send_mem, send_len, 0), 0);
+	EXPECT_GE(send(self->fd, send_mem, send_len, 0), 0);
+	memset(recv_mem, 0, total_len);
+	EXPECT_EQ(recv(self->cfd, recv_mem, total_len, 0), total_len);
+
+	EXPECT_EQ(memcmp(send_mem, recv_mem, send_len), 0);
+	EXPECT_EQ(memcmp(send_mem, recv_mem + send_len, send_len), 0);
+}
+
+TEST_F(tls, recv_partial)
+{
+	char const *test_str = "test_read_partial";
+	char const *test_str_first = "test_read";
+	char const *test_str_second = "_partial";
+	int send_len = strlen(test_str) + 1;
+	char recv_mem[18];
+
+	memset(recv_mem, 0, sizeof(recv_mem));
+	EXPECT_EQ(send(self->fd, test_str, send_len, 0), send_len);
+	EXPECT_NE(recv(self->cfd, recv_mem, strlen(test_str_first), 0), -1);
+	EXPECT_EQ(memcmp(test_str_first, recv_mem, strlen(test_str_first)), 0);
+	memset(recv_mem, 0, sizeof(recv_mem));
+	EXPECT_NE(recv(self->cfd, recv_mem, strlen(test_str_second), 0), -1);
+	EXPECT_EQ(memcmp(test_str_second, recv_mem, strlen(test_str_second)),
+		  0);
+}
+
+TEST_F(tls, recv_nonblock)
+{
+	char buf[4096];
+	bool err;
+
+	EXPECT_EQ(recv(self->cfd, buf, sizeof(buf), MSG_DONTWAIT), -1);
+	err = (errno == EAGAIN || errno == EWOULDBLOCK);
+	EXPECT_EQ(err, true);
+}
+
+TEST_F(tls, recv_peek)
+{
+	char const *test_str = "test_read_peek";
+	int send_len = strlen(test_str) + 1;
+	char buf[15];
+
+	EXPECT_EQ(send(self->fd, test_str, send_len, 0), send_len);
+	EXPECT_NE(recv(self->cfd, buf, send_len, MSG_PEEK), -1);
+	EXPECT_EQ(memcmp(test_str, buf, send_len), 0);
+	memset(buf, 0, sizeof(buf));
+	EXPECT_NE(recv(self->cfd, buf, send_len, 0), -1);
+	EXPECT_EQ(memcmp(test_str, buf, send_len), 0);
+}
+
+TEST_F(tls, recv_peek_multiple)
+{
+	char const *test_str = "test_read_peek";
+	int send_len = strlen(test_str) + 1;
+	unsigned int num_peeks = 100;
+	char buf[15];
+	int i;
+
+	EXPECT_EQ(send(self->fd, test_str, send_len, 0), send_len);
+	for (i = 0; i < num_peeks; i++) {
+		EXPECT_NE(recv(self->cfd, buf, send_len, MSG_PEEK), -1);
+		EXPECT_EQ(memcmp(test_str, buf, send_len), 0);
+		memset(buf, 0, sizeof(buf));
+	}
+	EXPECT_NE(recv(self->cfd, buf, send_len, 0), -1);
+	EXPECT_EQ(memcmp(test_str, buf, send_len), 0);
+}
+
+TEST_F(tls, pollin)
+{
+	char const *test_str = "test_poll";
+	struct pollfd fd = { 0, 0, 0 };
+	char buf[10];
+	int send_len = 10;
+
+	EXPECT_EQ(send(self->fd, test_str, send_len, 0), send_len);
+	fd.fd = self->cfd;
+	fd.events = POLLIN;
+
+	EXPECT_EQ(poll(&fd, 1, 20), 1);
+	EXPECT_EQ(fd.revents & POLLIN, 1);
+	EXPECT_EQ(recv(self->cfd, buf, send_len, 0), send_len);
+	/* Test timing out */
+	EXPECT_EQ(poll(&fd, 1, 20), 0);
+}
+
+TEST_F(tls, poll_wait)
+{
+	char const *test_str = "test_poll_wait";
+	int send_len = strlen(test_str) + 1;
+	struct pollfd fd = { 0, 0, 0 };
+	char recv_mem[15];
+
+	fd.fd = self->cfd;
+	fd.events = POLLIN;
+	EXPECT_EQ(send(self->fd, test_str, send_len, 0), send_len);
+	/* Set timeout to inf. secs */
+	EXPECT_EQ(poll(&fd, 1, -1), 1);
+	EXPECT_EQ(fd.revents & POLLIN, 1);
+	EXPECT_EQ(recv(self->cfd, recv_mem, send_len, 0), send_len);
+}
+
+TEST_F(tls, blocking)
+{
+	size_t data = 100000;
+	int res = fork();
+
+	EXPECT_NE(res, -1);
+
+	if (res) {
+		/* parent */
+		size_t left = data;
+		char buf[16384];
+		int status;
+		int pid2;
+
+		while (left) {
+			int res = send(self->fd, buf,
+				       left > 16384 ? 16384 : left, 0);
+
+			EXPECT_GE(res, 0);
+			left -= res;
+		}
+
+		pid2 = wait(&status);
+		EXPECT_EQ(status, 0);
+		EXPECT_EQ(res, pid2);
+	} else {
+		/* child */
+		size_t left = data;
+		char buf[16384];
+
+		while (left) {
+			int res = recv(self->cfd, buf,
+				       left > 16384 ? 16384 : left, 0);
+
+			EXPECT_GE(res, 0);
+			left -= res;
+		}
+	}
+}
+
+TEST_F(tls, nonblocking)
+{
+	size_t data = 100000;
+	int sendbuf = 100;
+	int flags;
+	int res;
+
+	flags = fcntl(self->fd, F_GETFL, 0);
+	fcntl(self->fd, F_SETFL, flags | O_NONBLOCK);
+	fcntl(self->cfd, F_SETFL, flags | O_NONBLOCK);
+
+	/* Ensure nonblocking behavior by imposing a small send
+	 * buffer.
+	 */
+	EXPECT_EQ(setsockopt(self->fd, SOL_SOCKET, SO_SNDBUF,
+			     &sendbuf, sizeof(sendbuf)), 0);
+
+	res = fork();
+	EXPECT_NE(res, -1);
+
+	if (res) {
+		/* parent */
+		bool eagain = false;
+		size_t left = data;
+		char buf[16384];
+		int status;
+		int pid2;
+
+		while (left) {
+			int res = send(self->fd, buf,
+				       left > 16384 ? 16384 : left, 0);
+
+			if (res == -1 && errno == EAGAIN) {
+				eagain = true;
+				usleep(10000);
+				continue;
+			}
+			EXPECT_GE(res, 0);
+			left -= res;
+		}
+
+		EXPECT_TRUE(eagain);
+		pid2 = wait(&status);
+
+		EXPECT_EQ(status, 0);
+		EXPECT_EQ(res, pid2);
+	} else {
+		/* child */
+		bool eagain = false;
+		size_t left = data;
+		char buf[16384];
+
+		while (left) {
+			int res = recv(self->cfd, buf,
+				       left > 16384 ? 16384 : left, 0);
+
+			if (res == -1 && errno == EAGAIN) {
+				eagain = true;
+				usleep(10000);
+				continue;
+			}
+			EXPECT_GE(res, 0);
+			left -= res;
+		}
+		EXPECT_TRUE(eagain);
+	}
+}
+
+TEST_F(tls, control_msg)
+{
+	if (self->notls)
+		return;
+
+	char cbuf[CMSG_SPACE(sizeof(char))];
+	char const *test_str = "test_read";
+	int cmsg_len = sizeof(char);
+	char record_type = 100;
+	struct cmsghdr *cmsg;
+	struct msghdr msg;
+	int send_len = 10;
+	struct iovec vec;
+	char buf[10];
+
+	vec.iov_base = (char *)test_str;
+	vec.iov_len = 10;
+	memset(&msg, 0, sizeof(struct msghdr));
+	msg.msg_iov = &vec;
+	msg.msg_iovlen = 1;
+	msg.msg_control = cbuf;
+	msg.msg_controllen = sizeof(cbuf);
+	cmsg = CMSG_FIRSTHDR(&msg);
+	cmsg->cmsg_level = SOL_TLS;
+	/* test sending non-record types. */
+	cmsg->cmsg_type = TLS_SET_RECORD_TYPE;
+	cmsg->cmsg_len = CMSG_LEN(cmsg_len);
+	*CMSG_DATA(cmsg) = record_type;
+	msg.msg_controllen = cmsg->cmsg_len;
+
+	EXPECT_EQ(sendmsg(self->fd, &msg, 0), send_len);
+	/* Should fail because we didn't provide a control message */
+	EXPECT_EQ(recv(self->cfd, buf, send_len, 0), -1);
+
+	vec.iov_base = buf;
+	EXPECT_EQ(recvmsg(self->cfd, &msg, 0), send_len);
+	cmsg = CMSG_FIRSTHDR(&msg);
+	EXPECT_NE(cmsg, NULL);
+	EXPECT_EQ(cmsg->cmsg_level, SOL_TLS);
+	EXPECT_EQ(cmsg->cmsg_type, TLS_GET_RECORD_TYPE);
+	record_type = *((unsigned char *)CMSG_DATA(cmsg));
+	EXPECT_EQ(record_type, 100);
+	EXPECT_EQ(memcmp(buf, test_str, send_len), 0);
+}
+
+TEST_HARNESS_MAIN