1 files changed, 151 insertions, 0 deletions
diff --git a/tests/contrib/test_net_shortwrite.c b/tests/contrib/test_net_shortwrite.c
new file mode 100644
index 0000000..f3d4c6e
--- /dev/null
+++ b/tests/contrib/test_net_shortwrite.c
@@ -0,0 +1,151 @@
+/*  Copyright (C) 2023 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <tap/basic.h>
+
+#include <fcntl.h>
+#include <stdint.h>
+#include <string.h>
+#include <pthread.h>
+#include <poll.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netdb.h>
+
+#include "libknot/errcode.h"
+#include "contrib/net.h"
+#include "contrib/sockaddr.h"
+
+const int TIMEOUT = 2000;
+
+static struct sockaddr_storage localhost(void)
+{
+	struct sockaddr_storage addr = { 0 };
+
+	struct addrinfo *res = NULL;
+	if (getaddrinfo(NULL, "0", NULL, &res) == 0) {
+		memcpy(&addr, res->ai_addr, res->ai_addrlen);
+		freeaddrinfo(res);
+	}
+
+	return addr;
+}
+
+struct data {
+	int server_fd;
+	uint8_t *buffer;
+	size_t size;
+	int result;
+};
+
+static void *thr_receive(void *data)
+{
+	struct data *d = data;
+
+	struct pollfd pfd = { .fd = d->server_fd, .events = POLLIN };
+	int r = poll(&pfd, 1, TIMEOUT);
+	if (r != 1) {
+		d->result = KNOT_ETIMEOUT;
+		return NULL;
+	}
+
+	int client = accept(d->server_fd, NULL, NULL);
+	if (client < 0) {
+		d->result = KNOT_ECONN;
+		return NULL;
+	}
+
+	d->result = net_dns_tcp_recv(client, d->buffer, d->size, TIMEOUT);
+
+	close(client);
+
+	return NULL;
+}
+
+int main(int argc, char *argv[])
+{
+	plan_lazy();
+
+	int r;
+
+	// create TCP server
+
+	struct sockaddr_storage addr = localhost();
+	int server = net_bound_socket(SOCK_STREAM, &addr, 0, 0);
+	ok(server >= 0, "server: bind socket");
+
+	r = listen(server, 1);
+	ok(r == 0, "server: start listening");
+
+	struct sockaddr *sa = (struct sockaddr *)&addr;
+	socklen_t salen = sockaddr_len(&addr);
+	r = getsockname(server, sa, &salen);
+	ok(r == 0, "server: get bound address");
+
+	// create TCP client
+
+	int client = net_connected_socket(SOCK_STREAM, &addr, NULL, false);
+	ok(client >= 0, "client: connect to server");
+
+	int optval = 8192;
+	socklen_t optlen = sizeof(optval);
+	r = setsockopt(client, SOL_SOCKET, SO_SNDBUF, &optval, optlen);
+	ok(r == 0, "client: configure small send buffer");
+
+	// accept TCP connection on the background
+
+	uint8_t recvbuf[UINT16_MAX] = { 0 };
+	struct data recv_data = {
+		.server_fd = server,
+		.buffer = recvbuf,
+		.size = sizeof(recvbuf)
+	};
+
+	pthread_t thr;
+	r = pthread_create(&thr, NULL, thr_receive, &recv_data);
+	ok(r == 0, "server: start receiver thread");
+
+	// send message (should handle partial-write correctly)
+
+	uint8_t sndbuf[UINT16_MAX];
+	for (size_t i = 0; i < sizeof(sndbuf); i++) {
+		sndbuf[i] = i;
+	}
+	r = net_dns_tcp_send(client, sndbuf, sizeof(sndbuf), TIMEOUT, NULL);
+	ok(r == sizeof(sndbuf), "client: net_dns_tcp_send() with short-write");
+
+	// receive message
+
+	r = pthread_join(thr, NULL);
+	ok(r == 0, "server: wait for receiver thread to terminate");
+
+	ok(recv_data.result == sizeof(recvbuf) &&
+	   memcmp(sndbuf, recvbuf, sizeof(recvbuf)) == 0,
+	   "server: net_dns_tcp_recv() complete and valid data");
+
+	// clean up
+
+	if (server >= 0) {
+		close(server);
+	}
+
+	if (client >= 0) {
+		close(client);
+	}
+
+	return 0;
+}