Clean up file and hello messes.

adsbus/file.c

@@ -0,0 +1,43 @@
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+#include "flow.h"
+#include "receive.h"
+#include "send.h"
+
+#include "file.h"
+
+void file_fd_new(int fd, struct flow *flow, void *passthrough) {
+	flow->new(fd, passthrough, NULL);
+	// TODO: log error; retry?
+	flow_hello(fd, flow, passthrough);
+}
+
+void file_read_new(char *path, struct flow *flow, void *passthrough) {
+	int fd = open(path, O_RDONLY | O_CLOEXEC);
+	if (fd == -1) {
+		// TODO: log error; retry?
+		return;
+	}
+	file_fd_new(fd, flow, passthrough);
+}
+
+void file_write_new(char *path, struct flow *flow, void *passthrough) {
+	int fd = open(path, O_WRONLY | O_CREAT | O_NOFOLLOW | O_TRUNC | O_CLOEXEC, S_IRUSR | S_IWUSR);
+	if (fd == -1) {
+		// TODO: log error; retry?
+		return;
+	}
+	file_fd_new(fd, flow, passthrough);
+}
+
+void file_append_new(char *path, struct flow *flow, void *passthrough) {
+	int fd = open(path, O_WRONLY | O_CREAT | O_NOFOLLOW | O_CLOEXEC, S_IRWXU);
+	if (fd == -1) {
+		// TODO: log error; retry?
+		return;
+	}
+	flow->new(fd, flow, passthrough);
+}