summaryrefslogtreecommitdiffstats
path: root/arch/um/os-Linux/drivers/tuntap_user.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/um/os-Linux/drivers/tuntap_user.c')
-rw-r--r--arch/um/os-Linux/drivers/tuntap_user.c215
1 files changed, 215 insertions, 0 deletions
diff --git a/arch/um/os-Linux/drivers/tuntap_user.c b/arch/um/os-Linux/drivers/tuntap_user.c
new file mode 100644
index 000000000..53eb3d508
--- /dev/null
+++ b/arch/um/os-Linux/drivers/tuntap_user.c
@@ -0,0 +1,215 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <linux/if_tun.h>
+#include <net/if.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include <sys/uio.h>
+#include <kern_util.h>
+#include <os.h>
+#include "tuntap.h"
+
+static int tuntap_user_init(void *data, void *dev)
+{
+ struct tuntap_data *pri = data;
+
+ pri->dev = dev;
+ return 0;
+}
+
+static void tuntap_add_addr(unsigned char *addr, unsigned char *netmask,
+ void *data)
+{
+ struct tuntap_data *pri = data;
+
+ tap_check_ips(pri->gate_addr, addr);
+ if ((pri->fd == -1) || pri->fixed_config)
+ return;
+ open_addr(addr, netmask, pri->dev_name);
+}
+
+static void tuntap_del_addr(unsigned char *addr, unsigned char *netmask,
+ void *data)
+{
+ struct tuntap_data *pri = data;
+
+ if ((pri->fd == -1) || pri->fixed_config)
+ return;
+ close_addr(addr, netmask, pri->dev_name);
+}
+
+struct tuntap_pre_exec_data {
+ int stdout_fd;
+ int close_me;
+};
+
+static void tuntap_pre_exec(void *arg)
+{
+ struct tuntap_pre_exec_data *data = arg;
+
+ dup2(data->stdout_fd, 1);
+ close(data->close_me);
+}
+
+static int tuntap_open_tramp(char *gate, int *fd_out, int me, int remote,
+ char *buffer, int buffer_len, int *used_out)
+{
+ struct tuntap_pre_exec_data data;
+ char version_buf[sizeof("nnnnn\0")];
+ char *argv[] = { "uml_net", version_buf, "tuntap", "up", gate,
+ NULL };
+ char buf[CMSG_SPACE(sizeof(*fd_out))];
+ struct msghdr msg;
+ struct cmsghdr *cmsg;
+ struct iovec iov;
+ int pid, n, err;
+
+ sprintf(version_buf, "%d", UML_NET_VERSION);
+
+ data.stdout_fd = remote;
+ data.close_me = me;
+
+ pid = run_helper(tuntap_pre_exec, &data, argv);
+
+ if (pid < 0)
+ return pid;
+
+ close(remote);
+
+ msg.msg_name = NULL;
+ msg.msg_namelen = 0;
+ if (buffer != NULL) {
+ iov = ((struct iovec) { buffer, buffer_len });
+ msg.msg_iov = &iov;
+ msg.msg_iovlen = 1;
+ }
+ else {
+ msg.msg_iov = NULL;
+ msg.msg_iovlen = 0;
+ }
+ msg.msg_control = buf;
+ msg.msg_controllen = sizeof(buf);
+ msg.msg_flags = 0;
+ n = recvmsg(me, &msg, 0);
+ *used_out = n;
+ if (n < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "tuntap_open_tramp : recvmsg failed - "
+ "errno = %d\n", errno);
+ return err;
+ }
+ helper_wait(pid);
+
+ cmsg = CMSG_FIRSTHDR(&msg);
+ if (cmsg == NULL) {
+ printk(UM_KERN_ERR "tuntap_open_tramp : didn't receive a "
+ "message\n");
+ return -EINVAL;
+ }
+ if ((cmsg->cmsg_level != SOL_SOCKET) ||
+ (cmsg->cmsg_type != SCM_RIGHTS)) {
+ printk(UM_KERN_ERR "tuntap_open_tramp : didn't receive a "
+ "descriptor\n");
+ return -EINVAL;
+ }
+ *fd_out = ((int *) CMSG_DATA(cmsg))[0];
+ os_set_exec_close(*fd_out);
+ return 0;
+}
+
+static int tuntap_open(void *data)
+{
+ struct ifreq ifr;
+ struct tuntap_data *pri = data;
+ char *output, *buffer;
+ int err, fds[2], len, used;
+
+ err = tap_open_common(pri->dev, pri->gate_addr);
+ if (err < 0)
+ return err;
+
+ if (pri->fixed_config) {
+ pri->fd = os_open_file("/dev/net/tun",
+ of_cloexec(of_rdwr(OPENFLAGS())), 0);
+ if (pri->fd < 0) {
+ printk(UM_KERN_ERR "Failed to open /dev/net/tun, "
+ "err = %d\n", -pri->fd);
+ return pri->fd;
+ }
+ memset(&ifr, 0, sizeof(ifr));
+ ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+ strlcpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name));
+ if (ioctl(pri->fd, TUNSETIFF, &ifr) < 0) {
+ err = -errno;
+ printk(UM_KERN_ERR "TUNSETIFF failed, errno = %d\n",
+ errno);
+ close(pri->fd);
+ return err;
+ }
+ }
+ else {
+ err = socketpair(AF_UNIX, SOCK_DGRAM, 0, fds);
+ if (err) {
+ err = -errno;
+ printk(UM_KERN_ERR "tuntap_open : socketpair failed - "
+ "errno = %d\n", errno);
+ return err;
+ }
+
+ buffer = get_output_buffer(&len);
+ if (buffer != NULL)
+ len--;
+ used = 0;
+
+ err = tuntap_open_tramp(pri->gate_addr, &pri->fd, fds[0],
+ fds[1], buffer, len, &used);
+
+ output = buffer;
+ if (err < 0) {
+ printk("%s", output);
+ free_output_buffer(buffer);
+ printk(UM_KERN_ERR "tuntap_open_tramp failed - "
+ "err = %d\n", -err);
+ return err;
+ }
+
+ pri->dev_name = uml_strdup(buffer);
+ output += IFNAMSIZ;
+ printk("%s", output);
+ free_output_buffer(buffer);
+
+ close(fds[0]);
+ iter_addresses(pri->dev, open_addr, pri->dev_name);
+ }
+
+ return pri->fd;
+}
+
+static void tuntap_close(int fd, void *data)
+{
+ struct tuntap_data *pri = data;
+
+ if (!pri->fixed_config)
+ iter_addresses(pri->dev, close_addr, pri->dev_name);
+ close(fd);
+ pri->fd = -1;
+}
+
+const struct net_user_info tuntap_user_info = {
+ .init = tuntap_user_init,
+ .open = tuntap_open,
+ .close = tuntap_close,
+ .remove = NULL,
+ .add_address = tuntap_add_addr,
+ .delete_address = tuntap_del_addr,
+ .mtu = ETH_MAX_PACKET,
+ .max_packet = ETH_MAX_PACKET + ETH_HEADER_OTHER,
+};