+/*
+ * Copyright (C) 2020 Daniel Golle <daniel@makrotopia.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#include <stdlib.h>
+#include <fcntl.h>
+#include <libubox/ustream.h>
+#include <libubus.h>
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <termios.h>
+
+static inline int setup_tios(int fd, struct termios *oldtios)
+{
+ struct termios newtios;
+
+ if (!isatty(fd)) {
+ return -1;
+ }
+
+ /* Get current termios */
+ if (tcgetattr(fd, oldtios))
+ return -1;
+
+ newtios = *oldtios;
+
+ /* Remove the echo characters and signal reception, the echo
+ * will be done with master proxying */
+ newtios.c_iflag &= ~IGNBRK;
+ newtios.c_iflag &= BRKINT;
+ newtios.c_lflag &= ~(ECHO|ICANON|ISIG);
+ newtios.c_cc[VMIN] = 1;
+ newtios.c_cc[VTIME] = 0;
+
+ /* Set new attributes */
+ if (tcsetattr(fd, TCSAFLUSH, &newtios))
+ return -1;
+
+ return 0;
+}
+
+
+
+#define OPT_ARGS "i:s:"
+
+static struct ustream_fd cufd;
+static struct ustream_fd lufd;
+
+static void usage()
+{
+ fprintf(stderr, "ujail-console -s <service> [-i <instance>]\n");
+ exit(1);
+}
+
+static void client_cb(struct ustream *s, int bytes)
+{
+ char *buf;
+ int len, rv;
+
+ do {
+ buf = ustream_get_read_buf(s, &len);
+ if (!buf)
+ break;
+
+ rv = ustream_write(&lufd.stream, buf, len, false);
+
+ if (rv > 0)
+ ustream_consume(s, rv);
+
+ if (rv <= len)
+ break;
+ } while(1);
+}
+
+static void local_cb(struct ustream *s, int bytes)
+{
+ char *buf;
+ int len, rv;
+
+ do {
+ buf = ustream_get_read_buf(s, &len);
+ if (!buf)
+ break;
+
+ if ((len > 0) && (buf[0] == 2))
+ uloop_end();
+
+ rv = ustream_write(&cufd.stream, buf, len, false);
+
+ if (rv > 0)
+ ustream_consume(s, rv);
+
+ if (rv <= len)
+ break;
+ } while(1);
+}
+
+int main(int argc, char **argv)
+{
+ struct ubus_context *ctx;
+ uint32_t id;
+ static struct blob_buf req;
+ char *service_name = NULL, *instance_name = NULL;
+ int client_fd, server_fd, tty_fd;
+ struct termios oldtermios;
+ int ch;
+
+ while ((ch = getopt(argc, argv, OPT_ARGS)) != -1) {
+ switch (ch) {
+ case 'i':
+ instance_name = optarg;
+ break;
+ case 's':
+ service_name = optarg;
+ break;
+ default:
+ usage();
+ }
+ }
+
+ if (!service_name)
+ usage();
+
+ ctx = ubus_connect(NULL);
+ if (!ctx) {
+ fprintf(stderr, "can't connect to ubus!\n");
+ return -1;
+ }
+
+ /* open pseudo-terminal pair */
+ client_fd = posix_openpt(O_RDWR | O_NOCTTY);
+ if (client_fd < 0) {
+ fprintf(stderr, "can't create virtual console!\n");
+ ubus_free(ctx);
+ return -1;
+ }
+ setup_tios(client_fd, &oldtermios);
+ grantpt(client_fd);
+ unlockpt(client_fd);
+ server_fd = open(ptsname(client_fd), O_RDWR | O_NOCTTY);
+ if (server_fd < 0) {
+ fprintf(stderr, "can't open virtual console!\n");
+ close(client_fd);
+ ubus_free(ctx);
+ return -1;
+ }
+
+ setup_tios(server_fd, &oldtermios);
+ tty_fd = open("/dev/tty", O_RDWR);
+ setup_tios(tty_fd, &oldtermios);
+
+ /* register server-side with procd */
+ blob_buf_init(&req, 0);
+ blobmsg_add_string(&req, "name", service_name);
+ if (instance_name)
+ blobmsg_add_string(&req, "instance", instance_name);
+
+ if (ubus_lookup_id(ctx, "service", &id) ||
+ ubus_invoke_fd(ctx, id, "console_attach", req.head, NULL, NULL, 3000, server_fd)) {
+ fprintf(stderr, "ubus request failed\n");
+ close(server_fd);
+ close(client_fd);
+ blob_buf_free(&req);
+ ubus_free(ctx);
+ return -2;
+ }
+
+ close(server_fd);
+ blob_buf_free(&req);
+ ubus_free(ctx);
+
+ uloop_init();
+
+ /* forward between stdio and client_fd until detach is requested */
+ lufd.stream.notify_read = local_cb;
+ ustream_fd_init(&lufd, tty_fd);
+
+ cufd.stream.notify_read = client_cb;
+/* ToDo: handle remote close and other events */
+// cufd.stream.notify_state = client_state_cb;
+ ustream_fd_init(&cufd, client_fd);
+
+ fprintf(stderr, "attaching to jail console. press [CTRL]+[B] to exit.\n");
+ close(0);
+ close(1);
+ close(2);
+ uloop_run();
+
+ tcsetattr(tty_fd, TCSAFLUSH, &oldtermios);
+ ustream_free(&lufd.stream);
+ ustream_free(&cufd.stream);
+ close(client_fd);
+
+ return 0;
+}