Factor out socket_io_try_{read,write}()

To be reused in Lua connection API.

2 files changed, 113 insertions, 80 deletions

diff --git a/common.c b/common.c
index 8974f57..a92bae4 100644
--- a/common.c
+++ b/common.c
@@ -95,6 +95,74 @@ xwrite (int fd, const char *data, size_t len, struct error **e)
 	return true;
 }
 
+// --- Simple network I/O ------------------------------------------------------
+
+// TODO: move to liberty and remove from dwmstatus.c as well
+
+#define SOCKET_IO_OVERFLOW (8 << 20)    ///< How large a read buffer can be
+
+enum socket_io_result
+{
+	SOCKET_IO_OK,                       ///< Completed successfully
+	SOCKET_IO_EOF,                      ///< Connection shut down by peer
+	SOCKET_IO_ERROR                     ///< Connection error
+};
+
+static enum socket_io_result
+socket_io_try_read (int socket_fd, struct str *rb, struct error **e)
+{
+	// We allow buffering of a fair amount of data, however within reason,
+	// so that it's not so easy to flood us and cause an allocation failure
+	ssize_t n_read;
+	while (rb->len < SOCKET_IO_OVERFLOW)
+	{
+		str_ensure_space (rb, 4096);
+		n_read = recv (socket_fd, rb->str + rb->len,
+			rb->alloc - rb->len - 1 /* null byte */, 0);
+
+		if (n_read > 0)
+		{
+			rb->str[rb->len += n_read] = '\0';
+			continue;
+		}
+		if (n_read == 0)
+			return SOCKET_IO_EOF;
+
+		if (errno == EAGAIN)
+			return SOCKET_IO_OK;
+		if (errno == EINTR)
+			continue;
+
+		error_set (e, "%s", strerror (errno));
+		return SOCKET_IO_ERROR;
+	}
+	return SOCKET_IO_OK;
+}
+
+static enum socket_io_result
+socket_io_try_write (int socket_fd, struct str *wb, struct error **e)
+{
+	ssize_t n_written;
+	while (wb->len)
+	{
+		n_written = send (socket_fd, wb->str, wb->len, 0);
+		if (n_written >= 0)
+		{
+			str_remove_slice (wb, 0, n_written);
+			continue;
+		}
+
+		if (errno == EAGAIN)
+			return SOCKET_IO_OK;
+		if (errno == EINTR)
+			continue;
+
+		error_set (e, "%s", strerror (errno));
+		return SOCKET_IO_ERROR;
+	}
+	return SOCKET_IO_OK;
+}
+
 // --- Logging -----------------------------------------------------------------
 
 static void
diff --git a/degesch.c b/degesch.c
index 4129e07..e1ec751 100644
--- a/degesch.c
+++ b/degesch.c
@@ -1139,13 +1139,6 @@ REF_COUNTABLE_METHODS (buffer)
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
-enum transport_io_result
-{
-	TRANSPORT_IO_OK = 0,                ///< Completed successfully
-	TRANSPORT_IO_EOF,                   ///< Connection shut down by peer
-	TRANSPORT_IO_ERROR                  ///< Connection error
-};
-
 // The only real purpose of this is to abstract away TLS
 struct transport
 {
@@ -1155,9 +1148,9 @@ struct transport
 	void (*cleanup) (struct server *s);
 
 	/// The underlying socket may have become readable, update `read_buffer'
-	enum transport_io_result (*try_read) (struct server *s);
+	enum socket_io_result (*try_read) (struct server *s);
 	/// The underlying socket may have become writeable, flush `write_buffer'
-	enum transport_io_result (*try_write) (struct server *s);
+	enum socket_io_result (*try_write) (struct server *s);
 	/// Return event mask to use in the poller
 	int (*get_poll_events) (struct server *s);
 
@@ -4219,27 +4212,27 @@ irc_process_buffer_custom (struct server *s, struct str *buf)
 	str_remove_slice (buf, 0, start - buf->str);
 }
 
-static enum transport_io_result
+static enum socket_io_result
 irc_try_read (struct server *s)
 {
-	enum transport_io_result result = s->transport->try_read (s);
+	enum socket_io_result result = s->transport->try_read (s);
 	if (s->read_buffer.len >= (1 << 20))
 	{
 		// XXX: this is stupid; if anything, count it in dependence of time
 		log_server_error (s, s->buffer,
 			"The IRC server seems to spew out data frantically");
-		return TRANSPORT_IO_ERROR;
+		return SOCKET_IO_ERROR;
 	}
 	if (s->read_buffer.len)
 		irc_process_buffer_custom (s, &s->read_buffer);
 	return result;
 }
 
-static enum transport_io_result
+static enum socket_io_result
 irc_try_write (struct server *s)
 {
-	enum transport_io_result result = s->transport->try_write (s);
-	if (result == TRANSPORT_IO_OK)
+	enum socket_io_result result = s->transport->try_write (s);
+	if (result == SOCKET_IO_OK)
 	{
 		// If we're flushing the write buffer and our job is complete, we send
 		// an EOF to the server, changing the state to IRC_HALF_CLOSED
@@ -4252,10 +4245,10 @@ irc_try_write (struct server *s)
 static bool
 irc_try_read_write (struct server *s)
 {
-	enum transport_io_result read_result;
-	enum transport_io_result write_result;
-	if ((read_result  = irc_try_read  (s)) == TRANSPORT_IO_ERROR
-	 || (write_result = irc_try_write (s)) == TRANSPORT_IO_ERROR)
+	enum socket_io_result read_result;
+	enum socket_io_result write_result;
+	if ((read_result  = irc_try_read  (s)) == SOCKET_IO_ERROR
+	 || (write_result = irc_try_write (s)) == SOCKET_IO_ERROR)
 	{
 		log_server_error (s, s->buffer, "Server connection failed");
 		return false;
@@ -4263,15 +4256,15 @@ irc_try_read_write (struct server *s)
 
 	// FIXME: this may probably fire multiple times when we're flushing,
 	//   we should probably store a flag next to the state
-	if (read_result  == TRANSPORT_IO_EOF
-	 || write_result == TRANSPORT_IO_EOF)
+	if (read_result  == SOCKET_IO_EOF
+	 || write_result == SOCKET_IO_EOF)
 		log_server_error (s, s->buffer, "Server closed the connection");
 
 	// If the write needs to read and we receive an EOF, we can't flush
-	if (write_result == TRANSPORT_IO_EOF)
+	if (write_result == SOCKET_IO_EOF)
 		return false;
 
-	if (read_result  == TRANSPORT_IO_EOF)
+	if (read_result  == SOCKET_IO_EOF)
 	{
 		// Eventually initiate shutdown to flush the write buffer
 		irc_shutdown (s);
@@ -4299,60 +4292,32 @@ on_irc_ready (const struct pollfd *pfd, struct server *s)
 
 // --- Plain transport ---------------------------------------------------------
 
-static enum transport_io_result
+static enum socket_io_result
 transport_plain_try_read (struct server *s)
 {
-	struct str *buf = &s->read_buffer;
-	ssize_t n_read;
-
-	while (true)
+	struct error *e = NULL;
+	enum socket_io_result result =
+		socket_io_try_read (s->socket, &s->read_buffer, &e);
+	if (e)
 	{
-		str_ensure_space (buf, 512);
-		n_read = recv (s->socket, buf->str + buf->len,
-			buf->alloc - buf->len - 1 /* null byte */, 0);
-
-		if (n_read > 0)
-		{
-			buf->str[buf->len += n_read] = '\0';
-			continue;
-		}
-		if (n_read == 0)
-			return TRANSPORT_IO_EOF;
-
-		if (errno == EAGAIN)
-			return TRANSPORT_IO_OK;
-		if (errno == EINTR)
-			continue;
-
-		LOG_LIBC_FAILURE ("recv");
-		return TRANSPORT_IO_ERROR;
+		print_debug ("%s: %s", __func__, e->message);
+		error_free (e);
 	}
+	return result;
 }
 
-static enum transport_io_result
+static enum socket_io_result
 transport_plain_try_write (struct server *s)
 {
-	struct str *buf = &s->write_buffer;
-	ssize_t n_written;
-
-	while (buf->len)
+	struct error *e = NULL;
+	enum socket_io_result result =
+		socket_io_try_write (s->socket, &s->write_buffer, &e);
+	if (e)
 	{
-		n_written = send (s->socket, buf->str, buf->len, 0);
-		if (n_written >= 0)
-		{
-			str_remove_slice (buf, 0, n_written);
-			continue;
-		}
-
-		if (errno == EAGAIN)
-			return TRANSPORT_IO_OK;
-		if (errno == EINTR)
-			continue;
-
-		LOG_LIBC_FAILURE ("send");
-		return TRANSPORT_IO_ERROR;
+		print_debug ("%s: %s", __func__, e->message);
+		error_free (e);
 	}
-	return TRANSPORT_IO_OK;
+	return result;
 }
 
 static int
@@ -4564,12 +4529,12 @@ transport_tls_cleanup (struct server *s)
 	free (data);
 }
 
-static enum transport_io_result
+static enum socket_io_result
 transport_tls_try_read (struct server *s)
 {
 	struct transport_tls_data *data = s->transport_data;
 	if (data->ssl_tx_want_rx)
-		return TRANSPORT_IO_OK;
+		return SOCKET_IO_OK;
 
 	struct str *buf = &s->read_buffer;
 	data->ssl_rx_want_tx = false;
@@ -4587,27 +4552,27 @@ transport_tls_try_read (struct server *s)
 			buf->str[buf->len += n_read] = '\0';
 			continue;
 		case SSL_ERROR_ZERO_RETURN:
-			return TRANSPORT_IO_EOF;
+			return SOCKET_IO_EOF;
 		case SSL_ERROR_WANT_READ:
-			return TRANSPORT_IO_OK;
+			return SOCKET_IO_OK;
 		case SSL_ERROR_WANT_WRITE:
 			data->ssl_rx_want_tx = true;
-			return TRANSPORT_IO_OK;
+			return SOCKET_IO_OK;
 		case XSSL_ERROR_TRY_AGAIN:
 			continue;
 		default:
 			LOG_FUNC_FAILURE ("SSL_read", error_info);
-			return TRANSPORT_IO_ERROR;
+			return SOCKET_IO_ERROR;
 		}
 	}
 }
 
-static enum transport_io_result
+static enum socket_io_result
 transport_tls_try_write (struct server *s)
 {
 	struct transport_tls_data *data = s->transport_data;
 	if (data->ssl_rx_want_tx)
-		return TRANSPORT_IO_OK;
+		return SOCKET_IO_OK;
 
 	struct str *buf = &s->write_buffer;
 	data->ssl_tx_want_rx = false;
@@ -4623,20 +4588,20 @@ transport_tls_try_write (struct server *s)
 			str_remove_slice (buf, 0, n_written);
 			continue;
 		case SSL_ERROR_ZERO_RETURN:
-			return TRANSPORT_IO_EOF;
+			return SOCKET_IO_EOF;
 		case SSL_ERROR_WANT_WRITE:
-			return TRANSPORT_IO_OK;
+			return SOCKET_IO_OK;
 		case SSL_ERROR_WANT_READ:
 			data->ssl_tx_want_rx = true;
-			return TRANSPORT_IO_OK;
+			return SOCKET_IO_OK;
 		case XSSL_ERROR_TRY_AGAIN:
 			continue;
 		default:
 			LOG_FUNC_FAILURE ("SSL_write", error_info);
-			return TRANSPORT_IO_ERROR;
+			return SOCKET_IO_ERROR;
 		}
 	}
-	return TRANSPORT_IO_OK;
+	return SOCKET_IO_OK;
 }
 
 static int