1 files changed, 143 insertions, 0 deletions
diff --git a/libc-bottom-half/sources/accept-wasip2.c b/libc-bottom-half/sources/accept-wasip2.c
new file mode 100644
index 0000000..3675958
--- /dev/null
+++ b/libc-bottom-half/sources/accept-wasip2.c
@@ -0,0 +1,143 @@
+#include <sys/socket.h>
+
+#include <errno.h>
+#include <netinet/in.h>
+#include <string.h>
+
+#include <wasi/api.h>
+#include <wasi/descriptor_table.h>
+#include <wasi/sockets_utils.h>
+
+int tcp_accept(tcp_socket_t *socket, bool client_blocking,
+	       struct sockaddr *addr, socklen_t *addrlen)
+{
+	output_sockaddr_t output_addr;
+	if (!__wasi_sockets_utils__output_addr_validate(
+		    socket->family, addr, addrlen, &output_addr)) {
+		errno = EINVAL;
+		return -1;
+	}
+
+	tcp_socket_state_listening_t listener;
+	if (socket->state.tag == TCP_SOCKET_STATE_LISTENING) {
+		listener = socket->state.listening;
+	} else {
+		errno = EINVAL;
+		return -1;
+	}
+
+	tcp_borrow_tcp_socket_t socket_borrow =
+		tcp_borrow_tcp_socket(socket->socket);
+
+	tcp_tuple3_own_tcp_socket_own_input_stream_own_output_stream_t
+		client_and_io;
+	network_error_code_t error;
+	while (!tcp_method_tcp_socket_accept(socket_borrow, &client_and_io,
+					     &error)) {
+		if (error == NETWORK_ERROR_CODE_WOULD_BLOCK) {
+			if (socket->blocking) {
+				poll_borrow_pollable_t pollable_borrow =
+					poll_borrow_pollable(
+						socket->socket_pollable);
+				poll_method_pollable_block(pollable_borrow);
+			} else {
+				errno = EWOULDBLOCK;
+				return -1;
+			}
+		} else {
+			errno = __wasi_sockets_utils__map_error(error);
+			return -1;
+		}
+	}
+
+	tcp_own_tcp_socket_t client = client_and_io.f0;
+	tcp_borrow_tcp_socket_t client_borrow = tcp_borrow_tcp_socket(client);
+
+	poll_own_pollable_t client_pollable =
+		tcp_method_tcp_socket_subscribe(client_borrow);
+
+	streams_own_input_stream_t input = client_and_io.f1;
+	streams_borrow_input_stream_t input_borrow =
+		streams_borrow_input_stream(input);
+	poll_own_pollable_t input_pollable =
+		streams_method_input_stream_subscribe(input_borrow);
+
+	streams_own_output_stream_t output = client_and_io.f2;
+	streams_borrow_output_stream_t output_borrow =
+		streams_borrow_output_stream(output);
+	poll_own_pollable_t output_pollable =
+		streams_method_output_stream_subscribe(output_borrow);
+
+	if (output_addr.tag != OUTPUT_SOCKADDR_NULL) {
+		network_ip_socket_address_t remote_address;
+		if (!tcp_method_tcp_socket_remote_address(
+			    client_borrow, &remote_address, &error)) {
+			// TODO wasi-sockets: How to recover from this in a POSIX compatible way?
+			abort();
+		}
+
+		__wasi_sockets_utils__output_addr_write(remote_address,
+							&output_addr);
+	}
+
+	descriptor_table_entry_t client_entry = { .tag = DESCRIPTOR_TABLE_ENTRY_TCP_SOCKET, .tcp_socket = {
+        .socket = client,
+        .socket_pollable = client_pollable,
+        .blocking = client_blocking,
+        .fake_nodelay = socket->fake_nodelay,
+        .family = socket->family,
+        .state = { .tag = TCP_SOCKET_STATE_CONNECTED, .connected = {
+            .input = input,
+            .input_pollable = input_pollable,
+            .output = output,
+            .output_pollable = output_pollable,
+        } },
+    } };
+
+	int client_fd;
+	if (!descriptor_table_insert(client_entry, &client_fd)) {
+		errno = EMFILE;
+		return -1;
+	}
+
+	return client_fd;
+}
+
+int udp_accept(udp_socket_t *socket, bool client_blocking,
+	       struct sockaddr *addr, socklen_t *addrlen)
+{
+	// UDP doesn't support accept
+	errno = EOPNOTSUPP;
+	return -1;
+}
+
+int accept(int socket, struct sockaddr *restrict addr,
+	   socklen_t *restrict addrlen)
+{
+	return accept4(socket, addr, addrlen, 0);
+}
+
+int accept4(int socket, struct sockaddr *restrict addr,
+	    socklen_t *restrict addrlen, int flags)
+{
+	descriptor_table_entry_t *entry;
+	if (!descriptor_table_get_ref(socket, &entry)) {
+		errno = EBADF;
+		return -1;
+	}
+
+	bool client_blocking = (flags & SOCK_NONBLOCK) == 0;
+	// Ignore SOCK_CLOEXEC flag. That concept does not exist in WASI.
+
+	switch (entry->tag) {
+	case DESCRIPTOR_TABLE_ENTRY_TCP_SOCKET:
+		return tcp_accept(&entry->tcp_socket, client_blocking, addr,
+				  addrlen);
+	case DESCRIPTOR_TABLE_ENTRY_UDP_SOCKET:
+		return udp_accept(&entry->udp_socket, client_blocking, addr,
+				  addrlen);
+	default:
+		errno = EOPNOTSUPP;
+		return -1;
+	}
+}