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-rw-r--r--networking/Config.in14
-rw-r--r--networking/Kbuild1
-rw-r--r--networking/tunctl.c139
3 files changed, 154 insertions, 0 deletions
diff --git a/networking/Config.in b/networking/Config.in
index 00a07b479..b3d07e63c 100644
--- a/networking/Config.in
+++ b/networking/Config.in
@@ -920,6 +920,20 @@ config TCPSVD
tcpsvd listens on a TCP port and runs a program for each new
connection.
+config TUNCTL
+ bool "tunctl"
+ default n
+ help
+ tunctl creates or deletes tun devices.
+
+config FEATURE_TUNCTL_UG
+ bool "Support owner:group assignment"
+ default n
+ depends on TUNCTL
+ help
+ Allow to specify owner and group of newly created interface.
+ 340 bytes of pure bloat. Say no here.
+
config UDPSVD
bool "udpsvd"
default n
diff --git a/networking/Kbuild b/networking/Kbuild
index 63d0745f8..77071269a 100644
--- a/networking/Kbuild
+++ b/networking/Kbuild
@@ -36,6 +36,7 @@ lib-$(CONFIG_TELNETD) += telnetd.o
lib-$(CONFIG_TFTP) += tftp.o
lib-$(CONFIG_TFTPD) += tftp.o
lib-$(CONFIG_TRACEROUTE) += traceroute.o
+lib-$(CONFIG_TUNCTL) += tunctl.o
lib-$(CONFIG_VCONFIG) += vconfig.o
lib-$(CONFIG_WGET) += wget.o
lib-$(CONFIG_ZCIP) += zcip.o
diff --git a/networking/tunctl.c b/networking/tunctl.c
new file mode 100644
index 000000000..a8e5270ad
--- /dev/null
+++ b/networking/tunctl.c
@@ -0,0 +1,139 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * tun devices controller
+ *
+ * Copyright (C) 2008 by Vladimir Dronnikov <dronnikov@gmail.com>
+ *
+ * Original code:
+ * Jeff Dike
+ *
+ * Licensed under GPLv2, see file LICENSE in this tarball for details.
+ */
+#include <netinet/in.h>
+#include <net/if.h>
+#include <linux/if_tun.h>
+#include "libbb.h"
+
+/* TUNSETGROUP appeared in 2.6.23 */
+#ifndef TUNSETGROUP
+#define TUNSETGROUP _IOW('T', 206, int)
+#endif
+
+#define IOCTL(a, b, c) ioctl_or_perror_and_die(a, b, c, NULL)
+
+#if 1
+
+int tunctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int tunctl_main(int argc UNUSED_PARAM, char **argv)
+{
+ struct ifreq ifr;
+ int fd;
+ const char *opt_name = "tap%d";
+ const char *opt_device = "/dev/net/tun";
+#if ENABLE_FEATURE_TUNCTL_UG
+ const char *opt_user, *opt_group;
+ long user = -1, group = -1;
+#endif
+ unsigned opts;
+
+ enum {
+ OPT_f = 1 << 0, // control device name (/dev/net/tun)
+ OPT_t = 1 << 1, // create named interface
+ OPT_d = 1 << 2, // delete named interface
+#if ENABLE_FEATURE_TUNCTL_UG
+ OPT_u = 1 << 3, // set new interface owner
+ OPT_g = 1 << 4, // set new interface group
+ OPT_b = 1 << 5, // brief output
+#endif
+ };
+
+ opt_complementary = "=0:t--d:d--t"; // no arguments; t ^ d
+ opts = getopt32(argv, "f:t:d:" USE_FEATURE_TUNCTL_UG("u:g:b"),
+ &opt_device, &opt_name, &opt_name
+ USE_FEATURE_TUNCTL_UG(, &opt_user, &opt_group));
+
+ // select device
+ memset(&ifr, 0, sizeof(ifr));
+ ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+ strncpy_IFNAMSIZ(ifr.ifr_name, opt_name);
+
+ // open device
+ fd = xopen(opt_device, O_RDWR);
+ IOCTL(fd, TUNSETIFF, (void *)&ifr);
+
+ // delete?
+ if (opts & OPT_d) {
+ IOCTL(fd, TUNSETPERSIST, (void *)(uintptr_t)0);
+ bb_info_msg("Set '%s' %spersistent", ifr.ifr_name, "non");
+ return EXIT_SUCCESS;
+ }
+
+ // create
+#if ENABLE_FEATURE_TUNCTL_UG
+ if (opts & OPT_g) {
+ group = xgroup2gid(opt_group);
+ IOCTL(fd, TUNSETGROUP, (void *)(uintptr_t)group);
+ } else
+ user = geteuid();
+ if (opts & OPT_u)
+ user = xuname2uid(opt_user);
+ IOCTL(fd, TUNSETOWNER, (void *)(uintptr_t)user);
+#endif
+ IOCTL(fd, TUNSETPERSIST, (void *)(uintptr_t)1);
+
+ // show info
+#if ENABLE_FEATURE_TUNCTL_UG
+ if (opts & OPT_b) {
+ puts(ifr.ifr_name);
+ } else {
+ printf("Set '%s' %spersistent", ifr.ifr_name, "");
+ printf(" and owned by uid %ld", user);
+ if (group != -1)
+ printf(" gid %ld", group);
+ bb_putchar('\n');
+ }
+#else
+ puts(ifr.ifr_name);
+#endif
+ return EXIT_SUCCESS;
+}
+
+#else
+
+/* -210 bytes: */
+
+int tunctl_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int tunctl_main(int argc UNUSED_PARAM, char **argv)
+{
+ struct ifreq ifr;
+ int fd;
+ const char *opt_name = "tap%d";
+ const char *opt_device = "/dev/net/tun";
+ unsigned opts;
+
+ enum {
+ OPT_f = 1 << 0, // control device name (/dev/net/tun)
+ OPT_t = 1 << 1, // create named interface
+ OPT_d = 1 << 2, // delete named interface
+ };
+
+ opt_complementary = "=0:t--d:d--t"; // no arguments; t ^ d
+ opts = getopt32(argv, "f:t:d:u:g:b", // u, g, b accepted and ignored
+ &opt_device, &opt_name, &opt_name, NULL, NULL);
+
+ // set interface name
+ memset(&ifr, 0, sizeof(ifr));
+ ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+ strncpy_IFNAMSIZ(ifr.ifr_name, opt_name);
+
+ // open device
+ fd = xopen(opt_device, O_RDWR);
+ IOCTL(fd, TUNSETIFF, (void *)&ifr);
+
+ // create or delete interface
+ IOCTL(fd, TUNSETPERSIST, (void *)(uintptr_t)(0 == (opts & OPT_d)));
+
+ return EXIT_SUCCESS;
+}
+
+#endif