refactor ubusd.c into reusable ubusd_library

In order to allow reusability in unit testing & fuzzing.

Signed-off-by: Petr Štetiar <ynezz@true.cz>

1 files changed, 271 insertions, 0 deletions

diff --git a/ubusd_main.c b/ubusd_main.c
new file mode 100644
index 0000000..81868c1
--- /dev/null
+++ b/ubusd_main.c
@@ -0,0 +1,271 @@
+/*
+ * Copyright (C) 2011-2014 Felix Fietkau <nbd@openwrt.org>
+ *
+ * SPDX-License-Identifier: LGPL-2.1-only
+ */
+
+#include <sys/socket.h>
+#include <sys/stat.h>
+#ifdef FreeBSD
+#include <sys/param.h>
+#endif
+#include <syslog.h>
+
+#include <libubox/usock.h>
+
+#include "ubusd.h"
+
+static struct ubus_msg_buf *ubus_msg_head(struct ubus_client *cl)
+{
+	return cl->tx_queue[cl->txq_cur];
+}
+
+static void ubus_msg_dequeue(struct ubus_client *cl)
+{
+	struct ubus_msg_buf *ub = ubus_msg_head(cl);
+
+	if (!ub)
+		return;
+
+	ubus_msg_free(ub);
+	cl->txq_ofs = 0;
+	cl->tx_queue[cl->txq_cur] = NULL;
+	cl->txq_cur = (cl->txq_cur + 1) % ARRAY_SIZE(cl->tx_queue);
+}
+
+static void handle_client_disconnect(struct ubus_client *cl)
+{
+	while (ubus_msg_head(cl))
+		ubus_msg_dequeue(cl);
+
+	ubusd_monitor_disconnect(cl);
+	ubusd_proto_free_client(cl);
+	if (cl->pending_msg_fd >= 0)
+		close(cl->pending_msg_fd);
+	uloop_fd_delete(&cl->sock);
+	close(cl->sock.fd);
+	free(cl);
+}
+
+static void client_cb(struct uloop_fd *sock, unsigned int events)
+{
+	struct ubus_client *cl = container_of(sock, struct ubus_client, sock);
+	struct ubus_msg_buf *ub;
+	static struct iovec iov;
+	static struct {
+		int fd;
+		struct cmsghdr h;
+	} fd_buf = {
+		.h = {
+			.cmsg_type = SCM_RIGHTS,
+			.cmsg_level = SOL_SOCKET,
+			.cmsg_len = sizeof(fd_buf),
+		}
+	};
+	struct msghdr msghdr = {
+		.msg_iov = &iov,
+		.msg_iovlen = 1,
+	};
+
+	/* first try to tx more pending data */
+	while ((ub = ubus_msg_head(cl))) {
+		ssize_t written;
+
+		written = ubus_msg_writev(sock->fd, ub, cl->txq_ofs);
+		if (written < 0) {
+			switch(errno) {
+			case EINTR:
+			case EAGAIN:
+				break;
+			default:
+				goto disconnect;
+			}
+			break;
+		}
+
+		cl->txq_ofs += written;
+		if (cl->txq_ofs < ub->len + sizeof(ub->hdr))
+			break;
+
+		ubus_msg_dequeue(cl);
+	}
+
+	/* prevent further ULOOP_WRITE events if we don't have data
+	 * to send anymore */
+	if (!ubus_msg_head(cl) && (events & ULOOP_WRITE))
+		uloop_fd_add(sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
+
+retry:
+	if (!sock->eof && cl->pending_msg_offset < (int) sizeof(cl->hdrbuf)) {
+		int offset = cl->pending_msg_offset;
+		int bytes;
+
+		fd_buf.fd = -1;
+
+		iov.iov_base = ((char *) &cl->hdrbuf) + offset;
+		iov.iov_len = sizeof(cl->hdrbuf) - offset;
+
+		if (cl->pending_msg_fd < 0) {
+			msghdr.msg_control = &fd_buf;
+			msghdr.msg_controllen = sizeof(fd_buf);
+		} else {
+			msghdr.msg_control = NULL;
+			msghdr.msg_controllen = 0;
+		}
+
+		bytes = recvmsg(sock->fd, &msghdr, 0);
+		if (bytes < 0)
+			goto out;
+
+		if (fd_buf.fd >= 0)
+			cl->pending_msg_fd = fd_buf.fd;
+
+		cl->pending_msg_offset += bytes;
+		if (cl->pending_msg_offset < (int) sizeof(cl->hdrbuf))
+			goto out;
+
+		if (blob_pad_len(&cl->hdrbuf.data) > UBUS_MAX_MSGLEN)
+			goto disconnect;
+
+		cl->pending_msg = ubus_msg_new(NULL, blob_raw_len(&cl->hdrbuf.data), false);
+		if (!cl->pending_msg)
+			goto disconnect;
+
+		cl->hdrbuf.hdr.seq = be16_to_cpu(cl->hdrbuf.hdr.seq);
+		cl->hdrbuf.hdr.peer = be32_to_cpu(cl->hdrbuf.hdr.peer);
+
+		memcpy(&cl->pending_msg->hdr, &cl->hdrbuf.hdr, sizeof(cl->hdrbuf.hdr));
+		memcpy(cl->pending_msg->data, &cl->hdrbuf.data, sizeof(cl->hdrbuf.data));
+	}
+
+	ub = cl->pending_msg;
+	if (ub) {
+		int offset = cl->pending_msg_offset - sizeof(ub->hdr);
+		int len = blob_raw_len(ub->data) - offset;
+		int bytes = 0;
+
+		if (len > 0) {
+			bytes = read(sock->fd, (char *) ub->data + offset, len);
+			if (bytes <= 0)
+				goto out;
+		}
+
+		if (bytes < len) {
+			cl->pending_msg_offset += bytes;
+			goto out;
+		}
+
+		/* accept message */
+		ub->fd = cl->pending_msg_fd;
+		cl->pending_msg_fd = -1;
+		cl->pending_msg_offset = 0;
+		cl->pending_msg = NULL;
+		ubusd_monitor_message(cl, ub, false);
+		ubusd_proto_receive_message(cl, ub);
+		goto retry;
+	}
+
+out:
+	if (!sock->eof || ubus_msg_head(cl))
+		return;
+
+disconnect:
+	handle_client_disconnect(cl);
+}
+
+static bool get_next_connection(int fd)
+{
+	struct ubus_client *cl;
+	int client_fd;
+
+	client_fd = accept(fd, NULL, 0);
+	if (client_fd < 0) {
+		switch (errno) {
+		case ECONNABORTED:
+		case EINTR:
+			return true;
+		default:
+			return false;
+		}
+	}
+
+	cl = ubusd_proto_new_client(client_fd, client_cb);
+	if (cl)
+		uloop_fd_add(&cl->sock, ULOOP_READ | ULOOP_EDGE_TRIGGER);
+	else
+		close(client_fd);
+
+	return true;
+}
+
+static void server_cb(struct uloop_fd *fd, unsigned int events)
+{
+	bool next;
+
+	do {
+		next = get_next_connection(fd->fd);
+	} while (next);
+}
+
+static struct uloop_fd server_fd = {
+	.cb = server_cb,
+};
+
+static int usage(const char *progname)
+{
+	fprintf(stderr, "Usage: %s [<options>]\n"
+		"Options: \n"
+		"  -A <path>:		Set the path to ACL files\n"
+		"  -s <socket>:		Set the unix domain socket to listen on\n"
+		"\n", progname);
+	return 1;
+}
+
+static void sighup_handler(int sig)
+{
+	ubusd_acl_load();
+}
+
+int main(int argc, char **argv)
+{
+	const char *ubus_socket = UBUS_UNIX_SOCKET;
+	int ret = 0;
+	int ch;
+
+	signal(SIGPIPE, SIG_IGN);
+	signal(SIGHUP, sighup_handler);
+
+	openlog("ubusd", LOG_PID, LOG_DAEMON);
+	uloop_init();
+
+	while ((ch = getopt(argc, argv, "A:s:")) != -1) {
+		switch (ch) {
+		case 's':
+			ubus_socket = optarg;
+			break;
+		case 'A':
+			ubusd_acl_dir = optarg;
+			break;
+		default:
+			return usage(argv[0]);
+		}
+	}
+
+	unlink(ubus_socket);
+	umask(0111);
+	server_fd.fd = usock(USOCK_UNIX | USOCK_SERVER | USOCK_NONBLOCK, ubus_socket, NULL);
+	if (server_fd.fd < 0) {
+		perror("usock");
+		ret = -1;
+		goto out;
+	}
+	uloop_fd_add(&server_fd, ULOOP_READ | ULOOP_EDGE_TRIGGER);
+	ubusd_acl_load();
+
+	uloop_run();
+	unlink(ubus_socket);
+
+out:
+	uloop_done();
+	return ret;
+}