Add a simple test for TCP sockets

Add two test programs, sockets-client.c and sockets-server.c, that
are run by the test driver as separate executables (since without
threads, this can't be written as a single test).

Author: catamorphism

test/Makefile

@@ -153,7 +153,15 @@ endif
 # Build up all the `*.wasm.o` object files; these are the same regardless of
 # whether we're building core modules or components.
 $(WASM_OBJS): $(INFRA_HEADERS)
-$(OBJDIR)/%.wasm.o: $(SRCDIR)/%.c $(DOWNLOADED) $(SYSROOT)
+
+# Sockets tests only run under wasm32-wasip2
+ifneq ($(TARGET_TRIPLE), wasm32-wasip2)
+C_SOURCES := $(shell find $(SRCDIR) -name '*.c' | grep -v sockets)
+else
+C_SOURCES := $(shell find $(SRCDIR) -name '*.c')
+endif
+
+$(OBJDIR)/%.wasm.o: $(C_SOURCES) $(DOWNLOADED) $(SYSROOT)
 	@mkdir -p $(@D)
 	$(CC) $(CFLAGS) $(shell scripts/add-flags.py CFLAGS $<) -c $< -o $@
 

test/scripts/run-test.sh

@@ -12,6 +12,40 @@ ENGINE="${ENGINE:-wasmtime}"
 [ -n "$WASM" ] || (echo "missing WASM variable" && exit 1)
 [ -n "$DIR" ] || (echo "missing DIR variable" && exit 1)
 
+# Run the client/server sockets test, which requires a client and server
+# running in separate processes
+run_sockets_test() {
+    # Args are the same for client and server
+    cd $DIR
+    server_wasm=`echo $WASM | sed -e 's/client/server/g'`
+    echo "$ENV $ENGINE $RUN $server_wasm $ARGS" > server_cmd.sh
+    chmod +x server_cmd.sh
+    # Start the server
+    ./server_cmd.sh &> server_output.log &
+    PID=$!
+    [ $? -ne -1 ] || (echo "Failed to start server $server_wasm" && exit 1)
+    echo "$ENV $ENGINE $RUN $WASM $ARGS" > cmd.sh
+    chmod +x cmd.sh
+    # Allow time for the server to start
+    sleep 1
+    # Start the client
+    ./cmd.sh &> output.log
+    test_result=$?
+    # Server normally exits on its own, but kill it in case the test failed
+    if [ ps -p $PID > /dev/null 2>&1 ]; then
+        kill -9 $PID
+    fi
+    [ $test_result -eq 0 ] || echo "Test failed" >> output.log
+}
+
+testname=$(basename $WASM)
+if [ $testname == "sockets-server.component.wasm" ]; then
+    exit 0
+fi
+if [ $testname == "sockets-client.component.wasm" ]; then
+    run_sockets_test
+    exit $?
+fi
 cd $DIR
 mkdir -p fs
 echo "$ENV $ENGINE $RUN $WASM $ARGS" > cmd.sh

test/src/misc/sockets-client.c

@@ -0,0 +1,64 @@
+//! add-flags.py(RUN): --wasi=inherit-network=y
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <netdb.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include "test.h"
+
+#define TEST(c) do { \
+	errno = 0; \
+	if (!(c)) \
+		t_error("%s failed (errno = %d)\n", #c, errno); \
+} while(0)
+
+int BUFSIZE = 256;
+
+// See sockets-server.c -- must be running already as a separate executable
+void test_tcp_client() {
+    // Prepare server socket
+    int server_port = 4001;
+
+    // Prepare client socket
+    // Use blocking sockets
+    int socket_fd = socket(AF_INET, SOCK_STREAM, 0);
+    TEST(socket_fd != -1);
+
+    // Prepare sockaddr_in for client
+    struct sockaddr_in sockaddr_in;
+    sockaddr_in.sin_addr.s_addr = htonl(INADDR_LOOPBACK);
+    sockaddr_in.sin_family = AF_INET;
+    sockaddr_in.sin_port = htons(server_port);
+
+    // Connect from client
+    char message[] = "There's gonna be a party when the wolf comes home";
+    int len = strlen(message);
+    char client_buffer[BUFSIZE];
+
+    TEST(connect(socket_fd, (struct sockaddr*)&sockaddr_in, sizeof(sockaddr_in)) != -1);
+
+    // Client writes a message to server
+    TEST(send(socket_fd, message, len, 0) == len);
+
+    // Client reads from server
+    int32_t bytes_received = recv(socket_fd, client_buffer, len, 0);
+    TEST(bytes_received == len);
+
+    // Message received should be the same as message sent
+    TEST(strcmp(message, client_buffer) == 0);
+
+    // Shut down client
+    close(socket_fd);
+}
+
+int main(void)
+{
+    test_tcp_client();
+
+    return t_status;
+}

test/src/misc/sockets-server.c

@@ -0,0 +1,67 @@
+//! add-flags.py(RUN): --wasi=inherit-network=y
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <netdb.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include "test.h"
+
+#define TEST(c) do { \
+	errno = 0; \
+	if (!(c)) \
+		t_error("%s failed (errno = %d)\n", #c, errno); \
+} while(0)
+
+int BUFSIZE = 256;
+
+void run_tcp_server() {
+    // Prepare server socket
+    int server_port = 4001;
+    // Use blocking sockets
+    int server_socket_fd = socket(AF_INET, SOCK_STREAM, 0);
+
+    // Bind server to socket
+    struct sockaddr_in server_address;
+    server_address.sin_family = AF_INET;
+    server_address.sin_addr.s_addr = htonl(INADDR_ANY);
+    server_address.sin_port = htons(server_port);
+    TEST(bind(server_socket_fd, (struct sockaddr*)&server_address, sizeof(server_address)) != -1);
+
+    // Listen on socket
+    char buffer[BUFSIZE];
+    socklen_t client_len = sizeof(struct sockaddr_in);
+    int client_socket_fd;
+    struct sockaddr_in client_address;
+    int32_t bytes_read = 0, total_bytes_read = 0;
+    TEST(listen(server_socket_fd, 1) != -1);
+
+    // Server accepts connection
+    client_socket_fd = accept(server_socket_fd, (struct sockaddr*)&client_address, &client_len);
+    TEST(client_socket_fd != -1);
+
+    // Server waits for input and echoes message back to client
+    // The server shuts down after the client closes the connection
+    while ((bytes_read = recv(client_socket_fd, buffer, BUFSIZE, 0)) > 0) {
+        total_bytes_read += bytes_read;
+        // Echo back the data received from the client
+        send(client_socket_fd, buffer, bytes_read, 0);
+    }
+
+    TEST(total_bytes_read > 0);
+
+    close(client_socket_fd);
+    close(server_socket_fd);
+}
+
+int main()
+{
+    run_tcp_server();
+
+    return t_status;
+}