enable unix socket and add test for it

src/libos/src/syscall/mod.rs

@@ -950,10 +950,10 @@ fn do_socket(domain: c_int, socket_type: c_int, protocol: c_int) -> Result<isize
     );
 
     let file_ref: Arc<Box<File>> = match domain {
-//        libc::AF_LOCAL => {
-//            let unix_socket = UnixSocketFile::new(socket_type, protocol)?;
-//            Arc::new(Box::new(unix_socket))
-//        }
+        libc::AF_LOCAL => {
+            let unix_socket = UnixSocketFile::new(socket_type, protocol)?;
+            Arc::new(Box::new(unix_socket))
+        }
         _ => {
             let socket = SocketFile::new(domain, socket_type, protocol)?;
             Arc::new(Box::new(socket))
@@ -1022,7 +1022,7 @@ fn do_accept4(
         let new_file_ref: Arc<Box<File>> = Arc::new(Box::new(new_socket));
         let new_fd = proc.get_files().lock().unwrap().put(new_file_ref, false);
 
-        Ok(0)
+        Ok(new_fd as isize)
     } else {
         errno!(EBADF, "not a socket")
     }
@@ -1147,14 +1147,19 @@ fn do_getpeername(
     let current_ref = process::get_current();
     let mut proc = current_ref.lock().unwrap();
     let file_ref = proc.get_files().lock().unwrap().get(fd as FileDesc)?;
-    let socket = file_ref.as_socket()?;
-
-    let ret = try_libc!(libc::ocall::getpeername(
-        socket.fd(),
-        addr,
-        addr_len
-    ));
-    Ok(ret as isize)
+    if let Ok(socket) = file_ref.as_socket() {
+        let ret = try_libc!(libc::ocall::getpeername(
+            socket.fd(),
+            addr,
+            addr_len
+        ));
+        Ok(ret as isize)
+    } else if let Ok(unix_socket) = file_ref.as_unix_socket() {
+        warn!("getpeername for unix socket is unimplemented");
+        Ok(0)
+    } else {
+        errno!(EBADF, "not a socket")
+    }
 }
 
 fn do_sendto(

test/Makefile

@@ -4,7 +4,7 @@ PROJECT_DIR := $(realpath $(CUR_DIR)/../)
 # Dependencies: need to be compiled but not to run by any Makefile target
 TEST_DEPS := dev_null
 # Tests: need to be compiled and run by test-% target
-TESTS := empty argv hello_world malloc file getpid spawn pipe time truncate readdir mkdir link tls pthread uname rlimit client server server_epoll
+TESTS := empty argv hello_world malloc file getpid spawn pipe time truncate readdir mkdir link tls pthread uname rlimit client server server_epoll unix_socket
 # Benchmarks: need to be compiled and run by bench-% target
 BENCHES := spawn_and_exit_latency pipe_throughput
 

test/unix_socket/Makefile

@@ -0,0 +1,5 @@
+include ../test_common.mk
+
+EXTRA_C_FLAGS := -Wno-incompatible-pointer-types-discards-qualifiers
+EXTRA_LINK_FLAGS :=
+BIN_ARGS :=

test/unix_socket/main.c

@@ -0,0 +1,117 @@
+#include <sys/syscall.h>
+#include <sys/wait.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <spawn.h>
+#include <string.h>
+
+const char SOCK_PATH[] = "echo_socket";
+
+int create_server_socket() {
+	int fd = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (fd == -1) {
+		printf("ERROR: failed to create a unix socket");
+		return -1;
+	}
+
+	struct sockaddr_un local;
+	local.sun_family = AF_UNIX;
+	strcpy(local.sun_path, SOCK_PATH);
+	socklen_t len = strlen(local.sun_path) + sizeof(local.sun_family);
+
+	if (bind(fd, (struct sockaddr *)&local, len) == -1) {
+		printf("ERROR: failed to bind\n");
+		return -1;
+	}
+
+	if (listen(fd, 5) == -1) {
+		printf("ERROR: failed to listen\n");
+		return -1;
+	}
+	return fd;
+}
+
+int create_client_socket() {
+	int fd = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (fd == -1) {
+		printf("ERROR: failed to create a unix socket");
+		return -1;
+	}
+
+	struct sockaddr_un remote;
+	remote.sun_family = AF_UNIX;
+	strcpy(remote.sun_path, SOCK_PATH);
+	socklen_t len = strlen(remote.sun_path) + sizeof(remote.sun_family);
+
+	if (connect(fd, (struct sockaddr *)&remote, len) == -1) {
+		printf("ERROR: failed to connect\n");
+		return -1;
+	}
+	return fd;
+}
+
+int main(int argc, const char* argv[]) {
+    // XXX: this is a hack! remove this in the future
+    void* ptr = malloc(64);
+    free(ptr);
+
+	int listen_fd = create_server_socket();
+	if (listen_fd == -1) {
+		printf("ERROR: failed to create server socket");
+		return -1;
+	}
+
+	int socket_rd_fd = create_client_socket();
+	if (socket_rd_fd == -1) {
+		printf("ERROR: failed to create client socket");
+		return -1;
+	}
+
+	struct sockaddr_un remote;
+	socklen_t len = sizeof(remote);
+	int socket_wr_fd = accept(listen_fd, (struct sockaddr *)&remote, &len);
+	if (socket_wr_fd == -1) {
+		printf("ERROR: failed to accept socket");
+		return -1;
+	}
+
+	// The following is same as 'pipe'
+
+    posix_spawn_file_actions_t file_actions;
+    posix_spawn_file_actions_init(&file_actions);
+    posix_spawn_file_actions_adddup2(&file_actions, socket_wr_fd, STDOUT_FILENO);
+    posix_spawn_file_actions_addclose(&file_actions, socket_rd_fd);
+
+    const char* msg = "Echo!\n";
+    const char* child_prog = "hello_world";
+    const char* child_argv[3] = { child_prog, msg, NULL };
+    int child_pid;
+    if (posix_spawn(&child_pid, child_prog, &file_actions,
+            NULL, child_argv, NULL) < 0) {
+        printf("ERROR: failed to spawn a child process\n");
+        return -1;
+    }
+    close(socket_wr_fd);
+
+    const char* expected_str = msg;
+    size_t expected_len = strlen(expected_str);
+    char actual_str[32] = {0};
+    ssize_t actual_len;
+    do {
+        actual_len = read(socket_rd_fd, actual_str, sizeof(actual_str) - 1);
+    } while (actual_len == 0);
+    if (strncmp(expected_str, actual_str, expected_len) != 0) {
+        printf("ERROR: received string is not as expected\n");
+        return -1;
+    }
+
+    int status = 0;
+    if (wait4(child_pid, &status, 0, NULL) < 0) {
+        printf("ERROR: failed to wait4 the child process\n");
+        return -1;
+    }
+    return 0;
+}