[linux-block.git] / arch / um / os-Linux / drivers / ethertap_user.c

// 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,
};
Commit	Line	Data
97870c34	1	// SPDX-License-Identifier: GPL-2.0
1da177e4	2	/*
cd1ae0e4	3	* Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
ef0470c0	4	* Copyright (C) 2001 Lennert Buytenhek (buytenh@gnu.org) and
1da177e4 LT	5	* James Leu (jleu@mindspring.net).
1da177e4 LT	6	* Copyright (C) 2001 by various other people who didn't put their name here.
1da177e4 LT	7	*/
	8
	9	#include <stdio.h>
	10	#include <unistd.h>
cd1ae0e4 JD	11	#include <errno.h>
cd1ae0e4 JD	12	#include <string.h>
1da177e4 LT	13	#include <sys/socket.h>
1da177e4 LT	14	#include <sys/wait.h>
1da177e4	15	#include "etap.h"
37185b33 AV	16	#include <os.h>
	17	#include <net_user.h>
	18	#include <um_malloc.h>
1da177e4 LT	19
	20	#define MAX_PACKET ETH_MAX_PACKET
	21
f34d9d2d	22	static int etap_user_init(void data, void dev)
1da177e4 LT	23	{
	24	struct ethertap_data *pri = data;
	25
	26	pri->dev = dev;
f34d9d2d	27	return 0;
1da177e4 LT	28	}
	29
	30	struct addr_change {
	31	enum { ADD_ADDR, DEL_ADDR } what;
	32	unsigned char addr[4];
	33	unsigned char netmask[4];
	34	};
	35
	36	static void etap_change(int op, unsigned char addr, unsigned char netmask,
	37	int fd)
	38	{
	39	struct addr_change change;
802e3077	40	char *output;
1da177e4 LT	41	int n;
	42
	43	change.what = op;
	44	memcpy(change.addr, addr, sizeof(change.addr));
	45	memcpy(change.netmask, netmask, sizeof(change.netmask));
a61f334f	46	CATCH_EINTR(n = write(fd, &change, sizeof(change)));
cd1ae0e4 JD	47	if (n != sizeof(change)) {
	48	printk(UM_KERN_ERR "etap_change - request failed, err = %d\n",
	49	errno);
ef0470c0 JD	50	return;
	51	}
	52
43f5b308	53	output = uml_kmalloc(UM_KERN_PAGE_SIZE, UM_GFP_KERNEL);
cd1ae0e4 JD	54	if (output == NULL)
	55	printk(UM_KERN_ERR "etap_change : Failed to allocate output "
	56	"buffer\n");
1ffb9164	57	read_output(fd, output, UM_KERN_PAGE_SIZE);
cd1ae0e4	58	if (output != NULL) {
1da177e4 LT	59	printk("%s", output);
	60	kfree(output);
	61	}
	62	}
	63
	64	static void etap_open_addr(unsigned char addr, unsigned char netmask,
	65	void *arg)
	66	{
	67	etap_change(ADD_ADDR, addr, netmask, ((int ) arg));
	68	}
	69
	70	static void etap_close_addr(unsigned char addr, unsigned char netmask,
	71	void *arg)
	72	{
	73	etap_change(DEL_ADDR, addr, netmask, ((int ) arg));
	74	}
	75
	76	struct etap_pre_exec_data {
	77	int control_remote;
	78	int control_me;
	79	int data_me;
	80	};
	81
	82	static void etap_pre_exec(void *arg)
	83	{
	84	struct etap_pre_exec_data *data = arg;
	85
	86	dup2(data->control_remote, 1);
512b6fb1 JD	87	close(data->data_me);
512b6fb1 JD	88	close(data->control_me);
1da177e4 LT	89	}
1da177e4 LT	90
512b6fb1	91	static int etap_tramp(char dev, char gate, int control_me,
1da177e4 LT	92	int control_remote, int data_me, int data_remote)
	93	{
	94	struct etap_pre_exec_data pe_data;
4dbed85a	95	int pid, err, n;
1da177e4 LT	96	char version_buf[sizeof("nnnnn\0")];
	97	char data_fd_buf[sizeof("nnnnnn\0")];
	98	char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
	99	char *setup_args[] = { "uml_net", version_buf, "ethertap", dev,
	100	data_fd_buf, gate_buf, NULL };
512b6fb1	101	char *nosetup_args[] = { "uml_net", version_buf, "ethertap",
1da177e4 LT	102	dev, data_fd_buf, NULL };
	103	char **args, c;
	104
	105	sprintf(data_fd_buf, "%d", data_remote);
	106	sprintf(version_buf, "%d", UML_NET_VERSION);
cd1ae0e4	107	if (gate != NULL) {
7879b1d9	108	strncpy(gate_buf, gate, 15);
1da177e4 LT	109	args = setup_args;
	110	}
	111	else args = nosetup_args;
	112
	113	err = 0;
	114	pe_data.control_remote = control_remote;
	115	pe_data.control_me = control_me;
	116	pe_data.data_me = data_me;
c4399016	117	pid = run_helper(etap_pre_exec, &pe_data, args);
1da177e4	118
cd1ae0e4	119	if (pid < 0)
ef0470c0	120	err = pid;
512b6fb1 JD	121	close(data_remote);
512b6fb1 JD	122	close(control_remote);
a61f334f	123	CATCH_EINTR(n = read(control_me, &c, sizeof(c)));
cd1ae0e4	124	if (n != sizeof(c)) {
a61f334f	125	err = -errno;
cd1ae0e4 JD	126	printk(UM_KERN_ERR "etap_tramp : read of status failed, "
cd1ae0e4 JD	127	"err = %d\n", -err);
a61f334f	128	return err;
1da177e4	129	}
cd1ae0e4 JD	130	if (c != 1) {
cd1ae0e4 JD	131	printk(UM_KERN_ERR "etap_tramp : uml_net failed\n");
1aa351a3	132	err = helper_wait(pid);
1da177e4	133	}
56bd194b	134	return err;
1da177e4 LT	135	}
	136
	137	static int etap_open(void *data)
	138	{
	139	struct ethertap_data *pri = data;
	140	char *output;
	141	int data_fds[2], control_fds[2], err, output_len;
	142
	143	err = tap_open_common(pri->dev, pri->gate_addr);
cd1ae0e4	144	if (err)
56bd194b	145	return err;
1da177e4	146
512b6fb1	147	err = socketpair(AF_UNIX, SOCK_DGRAM, 0, data_fds);
cd1ae0e4	148	if (err) {
512b6fb1	149	err = -errno;
cd1ae0e4 JD	150	printk(UM_KERN_ERR "etap_open - data socketpair failed - "
cd1ae0e4 JD	151	"err = %d\n", errno);
56bd194b	152	return err;
1da177e4 LT	153	}
1da177e4 LT	154
512b6fb1	155	err = socketpair(AF_UNIX, SOCK_STREAM, 0, control_fds);
cd1ae0e4	156	if (err) {
512b6fb1	157	err = -errno;
cd1ae0e4 JD	158	printk(UM_KERN_ERR "etap_open - control socketpair failed - "
cd1ae0e4 JD	159	"err = %d\n", errno);
512b6fb1	160	goto out_close_data;
1da177e4	161	}
56bd194b	162
512b6fb1	163	err = etap_tramp(pri->dev_name, pri->gate_addr, control_fds[0],
1da177e4	164	control_fds[1], data_fds[0], data_fds[1]);
1ffb9164	165	output_len = UM_KERN_PAGE_SIZE;
43f5b308	166	output = uml_kmalloc(output_len, UM_GFP_KERNEL);
1da177e4 LT	167	read_output(control_fds[0], output, output_len);
1da177e4 LT	168
cd1ae0e4 JD	169	if (output == NULL)
	170	printk(UM_KERN_ERR "etap_open : failed to allocate output "
	171	"buffer\n");
1da177e4 LT	172	else {
	173	printk("%s", output);
	174	kfree(output);
	175	}
	176
cd1ae0e4 JD	177	if (err < 0) {
cd1ae0e4 JD	178	printk(UM_KERN_ERR "etap_tramp failed - err = %d\n", -err);
512b6fb1	179	goto out_close_control;
1da177e4 LT	180	}
	181
	182	pri->data_fd = data_fds[0];
	183	pri->control_fd = control_fds[0];
	184	iter_addresses(pri->dev, etap_open_addr, &pri->control_fd);
56bd194b	185	return data_fds[0];
512b6fb1 JD	186
	187	out_close_control:
	188	close(control_fds[0]);
	189	close(control_fds[1]);
	190	out_close_data:
	191	close(data_fds[0]);
	192	close(data_fds[1]);
	193	return err;
1da177e4 LT	194	}
	195
	196	static void etap_close(int fd, void *data)
	197	{
	198	struct ethertap_data *pri = data;
	199
	200	iter_addresses(pri->dev, etap_close_addr, &pri->control_fd);
512b6fb1 JD	201	close(fd);
512b6fb1 JD	202
cd1ae0e4 JD	203	if (shutdown(pri->data_fd, SHUT_RDWR) < 0)
cd1ae0e4 JD	204	printk(UM_KERN_ERR "etap_close - shutdown data socket failed, "
512b6fb1 JD	205	"errno = %d\n", errno);
512b6fb1 JD	206
cd1ae0e4 JD	207	if (shutdown(pri->control_fd, SHUT_RDWR) < 0)
	208	printk(UM_KERN_ERR "etap_close - shutdown control socket "
	209	"failed, errno = %d\n", errno);
	210
512b6fb1	211	close(pri->data_fd);
1da177e4	212	pri->data_fd = -1;
512b6fb1	213	close(pri->control_fd);
1da177e4 LT	214	pri->control_fd = -1;
	215	}
	216
1da177e4 LT	217	static void etap_add_addr(unsigned char addr, unsigned char netmask,
	218	void *data)
	219	{
	220	struct ethertap_data *pri = data;
	221
	222	tap_check_ips(pri->gate_addr, addr);
cd1ae0e4	223	if (pri->control_fd == -1)
56bd194b	224	return;
1da177e4 LT	225	etap_open_addr(addr, netmask, &pri->control_fd);
	226	}
	227
512b6fb1	228	static void etap_del_addr(unsigned char addr, unsigned char netmask,
1da177e4 LT	229	void *data)
	230	{
	231	struct ethertap_data *pri = data;
	232
cd1ae0e4	233	if (pri->control_fd == -1)
56bd194b	234	return;
512b6fb1	235
1da177e4 LT	236	etap_close_addr(addr, netmask, &pri->control_fd);
	237	}
	238
5e7672ec	239	const struct net_user_info ethertap_user_info = {
1da177e4 LT	240	.init = etap_user_init,
	241	.open = etap_open,
	242	.close = etap_close,
	243	.remove = NULL,
1da177e4 LT	244	.add_address = etap_add_addr,
1da177e4 LT	245	.delete_address = etap_del_addr,
b53f35a8 JD	246	.mtu = ETH_MAX_PACKET,
b53f35a8 JD	247	.max_packet = ETH_MAX_PACKET + ETH_HEADER_ETHERTAP,
1da177e4	248	};