1 files changed, 248 insertions, 0 deletions
diff --git a/arch/um/os-Linux/drivers/ethertap_user.c b/arch/um/os-Linux/drivers/ethertap_user.c
new file mode 100644
index 000000000..9483021d8
--- /dev/null
+++ b/arch/um/os-Linux/drivers/ethertap_user.c
@@ -0,0 +1,248 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
+ * Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
+ * James Leu (jleu@mindspring.net).
+ * Copyright (C) 2001 by various other people who didn't put their name here.
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/wait.h>
+#include "etap.h"
+#include <os.h>
+#include <net_user.h>
+#include <um_malloc.h>
+
+#define MAX_PACKET ETH_MAX_PACKET
+
+static int etap_user_init(void *data, void *dev)
+{
+	struct ethertap_data *pri = data;
+
+	pri->dev = dev;
+	return 0;
+}
+
+struct addr_change {
+	enum { ADD_ADDR, DEL_ADDR } what;
+	unsigned char addr[4];
+	unsigned char netmask[4];
+};
+
+static void etap_change(int op, unsigned char *addr, unsigned char *netmask,
+			int fd)
+{
+	struct addr_change change;
+	char *output;
+	int n;
+
+	change.what = op;
+	memcpy(change.addr, addr, sizeof(change.addr));
+	memcpy(change.netmask, netmask, sizeof(change.netmask));
+	CATCH_EINTR(n = write(fd, &change, sizeof(change)));
+	if (n != sizeof(change)) {
+		printk(UM_KERN_ERR "etap_change - request failed, err = %d\n",
+		       errno);
+		return;
+	}
+
+	output = uml_kmalloc(UM_KERN_PAGE_SIZE, UM_GFP_KERNEL);
+	if (output == NULL)
+		printk(UM_KERN_ERR "etap_change : Failed to allocate output "
+		       "buffer\n");
+	read_output(fd, output, UM_KERN_PAGE_SIZE);
+	if (output != NULL) {
+		printk("%s", output);
+		kfree(output);
+	}
+}
+
+static void etap_open_addr(unsigned char *addr, unsigned char *netmask,
+			   void *arg)
+{
+	etap_change(ADD_ADDR, addr, netmask, *((int *) arg));
+}
+
+static void etap_close_addr(unsigned char *addr, unsigned char *netmask,
+			    void *arg)
+{
+	etap_change(DEL_ADDR, addr, netmask, *((int *) arg));
+}
+
+struct etap_pre_exec_data {
+	int control_remote;
+	int control_me;
+	int data_me;
+};
+
+static void etap_pre_exec(void *arg)
+{
+	struct etap_pre_exec_data *data = arg;
+
+	dup2(data->control_remote, 1);
+	close(data->data_me);
+	close(data->control_me);
+}
+
+static int etap_tramp(char *dev, char *gate, int control_me,
+		      int control_remote, int data_me, int data_remote)
+{
+	struct etap_pre_exec_data pe_data;
+	int pid, err, n;
+	char version_buf[sizeof("nnnnn\0")];
+	char data_fd_buf[sizeof("nnnnnn\0")];
+	char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
+	char *setup_args[] = { "uml_net", version_buf, "ethertap", dev,
+			       data_fd_buf, gate_buf, NULL };
+	char *nosetup_args[] = { "uml_net", version_buf, "ethertap",
+				 dev, data_fd_buf, NULL };
+	char **args, c;
+
+	sprintf(data_fd_buf, "%d", data_remote);
+	sprintf(version_buf, "%d", UML_NET_VERSION);
+	if (gate != NULL) {
+		strncpy(gate_buf, gate, 15);
+		args = setup_args;
+	}
+	else args = nosetup_args;
+
+	err = 0;
+	pe_data.control_remote = control_remote;
+	pe_data.control_me = control_me;
+	pe_data.data_me = data_me;
+	pid = run_helper(etap_pre_exec, &pe_data, args);
+
+	if (pid < 0)
+		err = pid;
+	close(data_remote);
+	close(control_remote);
+	CATCH_EINTR(n = read(control_me, &c, sizeof(c)));
+	if (n != sizeof(c)) {
+		err = -errno;
+		printk(UM_KERN_ERR "etap_tramp : read of status failed, "
+		       "err = %d\n", -err);
+		return err;
+	}
+	if (c != 1) {
+		printk(UM_KERN_ERR "etap_tramp : uml_net failed\n");
+		err = helper_wait(pid);
+	}
+	return err;
+}
+
+static int etap_open(void *data)
+{
+	struct ethertap_data *pri = data;
+	char *output;
+	int data_fds[2], control_fds[2], err, output_len;
+
+	err = tap_open_common(pri->dev, pri->gate_addr);
+	if (err)
+		return err;
+
+	err = socketpair(AF_UNIX, SOCK_DGRAM, 0, data_fds);
+	if (err) {
+		err = -errno;
+		printk(UM_KERN_ERR "etap_open - data socketpair failed - "
+		       "err = %d\n", errno);
+		return err;
+	}
+
+	err = socketpair(AF_UNIX, SOCK_STREAM, 0, control_fds);
+	if (err) {
+		err = -errno;
+		printk(UM_KERN_ERR "etap_open - control socketpair failed - "
+		       "err = %d\n", errno);
+		goto out_close_data;
+	}
+
+	err = etap_tramp(pri->dev_name, pri->gate_addr, control_fds[0],
+			 control_fds[1], data_fds[0], data_fds[1]);
+	output_len = UM_KERN_PAGE_SIZE;
+	output = uml_kmalloc(output_len, UM_GFP_KERNEL);
+	read_output(control_fds[0], output, output_len);
+
+	if (output == NULL)
+		printk(UM_KERN_ERR "etap_open : failed to allocate output "
+		       "buffer\n");
+	else {
+		printk("%s", output);
+		kfree(output);
+	}
+
+	if (err < 0) {
+		printk(UM_KERN_ERR "etap_tramp failed - err = %d\n", -err);
+		goto out_close_control;
+	}
+
+	pri->data_fd = data_fds[0];
+	pri->control_fd = control_fds[0];
+	iter_addresses(pri->dev, etap_open_addr, &pri->control_fd);
+	return data_fds[0];
+
+out_close_control:
+	close(control_fds[0]);
+	close(control_fds[1]);
+out_close_data:
+	close(data_fds[0]);
+	close(data_fds[1]);
+	return err;
+}
+
+static void etap_close(int fd, void *data)
+{
+	struct ethertap_data *pri = data;
+
+	iter_addresses(pri->dev, etap_close_addr, &pri->control_fd);
+	close(fd);
+
+	if (shutdown(pri->data_fd, SHUT_RDWR) < 0)
+		printk(UM_KERN_ERR "etap_close - shutdown data socket failed, "
+		       "errno = %d\n", errno);
+
+	if (shutdown(pri->control_fd, SHUT_RDWR) < 0)
+		printk(UM_KERN_ERR "etap_close - shutdown control socket "
+		       "failed, errno = %d\n", errno);
+
+	close(pri->data_fd);
+	pri->data_fd = -1;
+	close(pri->control_fd);
+	pri->control_fd = -1;
+}
+
+static void etap_add_addr(unsigned char *addr, unsigned char *netmask,
+			  void *data)
+{
+	struct ethertap_data *pri = data;
+
+	tap_check_ips(pri->gate_addr, addr);
+	if (pri->control_fd == -1)
+		return;
+	etap_open_addr(addr, netmask, &pri->control_fd);
+}
+
+static void etap_del_addr(unsigned char *addr, unsigned char *netmask,
+			  void *data)
+{
+	struct ethertap_data *pri = data;
+
+	if (pri->control_fd == -1)
+		return;
+
+	etap_close_addr(addr, netmask, &pri->control_fd);
+}
+
+const struct net_user_info ethertap_user_info = {
+	.init		= etap_user_init,
+	.open		= etap_open,
+	.close	 	= etap_close,
+	.remove	 	= NULL,
+	.add_address	= etap_add_addr,
+	.delete_address = etap_del_addr,
+	.mtu		= ETH_MAX_PACKET,
+	.max_packet	= ETH_MAX_PACKET + ETH_HEADER_ETHERTAP,
+};