1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 */
5
6#include <stdio.h>
7#include <stdlib.h>
8#include <unistd.h>
9#include <errno.h>
10#include <fcntl.h>
11#include <string.h>
12#include <termios.h>
13#include <sys/wait.h>
14#include <net_user.h>
15#include <os.h>
16#include "slip.h"
17#include <um_malloc.h>
18
19static int slip_user_init(void *data, void *dev)
20{
21	struct slip_data *pri = data;
22
23	pri->dev = dev;
24	return 0;
25}
26
27static int set_up_tty(int fd)
28{
29	int i;
30	struct termios tios;
31
32	if (tcgetattr(fd, &tios) < 0) {
33		printk(UM_KERN_ERR "could not get initial terminal "
34		       "attributes\n");
35		return -1;
36	}
37
38	tios.c_cflag = CS8 | CREAD | HUPCL | CLOCAL;
39	tios.c_iflag = IGNBRK | IGNPAR;
40	tios.c_oflag = 0;
41	tios.c_lflag = 0;
42	for (i = 0; i < NCCS; i++)
43		tios.c_cc[i] = 0;
44	tios.c_cc[VMIN] = 1;
45	tios.c_cc[VTIME] = 0;
46
47	cfsetospeed(&tios, B38400);
48	cfsetispeed(&tios, B38400);
49
50	if (tcsetattr(fd, TCSAFLUSH, &tios) < 0) {
51		printk(UM_KERN_ERR "failed to set terminal attributes\n");
52		return -1;
53	}
54	return 0;
55}
56
57struct slip_pre_exec_data {
58	int stdin_fd;
59	int stdout_fd;
60	int close_me;
61};
62
63static void slip_pre_exec(void *arg)
64{
65	struct slip_pre_exec_data *data = arg;
66
67	if (data->stdin_fd >= 0)
68		dup2(data->stdin_fd, 0);
69	dup2(data->stdout_fd, 1);
70	if (data->close_me >= 0)
71		close(data->close_me);
72}
73
74static int slip_tramp(char **argv, int fd)
75{
76	struct slip_pre_exec_data pe_data;
77	char *output;
78	int pid, fds[2], err, output_len;
79
80	err = os_pipe(fds, 1, 0);
81	if (err < 0) {
82		printk(UM_KERN_ERR "slip_tramp : pipe failed, err = %d\n",
83		       -err);
84		goto out;
85	}
86
87	err = 0;
88	pe_data.stdin_fd = fd;
89	pe_data.stdout_fd = fds[1];
90	pe_data.close_me = fds[0];
91	err = run_helper(slip_pre_exec, &pe_data, argv);
92	if (err < 0)
93		goto out_close;
94	pid = err;
95
96	output_len = UM_KERN_PAGE_SIZE;
97	output = uml_kmalloc(output_len, UM_GFP_KERNEL);
98	if (output == NULL) {
99		printk(UM_KERN_ERR "slip_tramp : failed to allocate output "
100		       "buffer\n");
101		os_kill_process(pid, 1);
102		err = -ENOMEM;
103		goto out_close;
104	}
105
106	close(fds[1]);
107	read_output(fds[0], output, output_len);
108	printk("%s", output);
109
110	err = helper_wait(pid);
111	close(fds[0]);
112
113	kfree(output);
114	return err;
115
116out_close:
117	close(fds[0]);
118	close(fds[1]);
119out:
120	return err;
121}
122
123static int slip_open(void *data)
124{
125	struct slip_data *pri = data;
126	char version_buf[sizeof("nnnnn\0")];
127	char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
128	char *argv[] = { "uml_net", version_buf, "slip", "up", gate_buf,
129			 NULL };
130	int sfd, mfd, err;
131
132	err = get_pty();
133	if (err < 0) {
134		printk(UM_KERN_ERR "slip-open : Failed to open pty, err = %d\n",
135		       -err);
136		goto out;
137	}
138	mfd = err;
139
140	err = open(ptsname(mfd), O_RDWR, 0);
141	if (err < 0) {
142		printk(UM_KERN_ERR "Couldn't open tty for slip line, "
143		       "err = %d\n", -err);
144		goto out_close;
145	}
146	sfd = err;
147
148	err = set_up_tty(sfd);
149	if (err)
150		goto out_close2;
151
152	pri->slave = sfd;
153	pri->slip.pos = 0;
154	pri->slip.esc = 0;
155	if (pri->gate_addr != NULL) {
156		sprintf(version_buf, "%d", UML_NET_VERSION);
157		strcpy(gate_buf, pri->gate_addr);
158
159		err = slip_tramp(argv, sfd);
160
161		if (err < 0) {
162			printk(UM_KERN_ERR "slip_tramp failed - err = %d\n",
163			       -err);
164			goto out_close2;
165		}
166		err = os_get_ifname(pri->slave, pri->name);
167		if (err < 0) {
168			printk(UM_KERN_ERR "get_ifname failed, err = %d\n",
169			       -err);
170			goto out_close2;
171		}
172		iter_addresses(pri->dev, open_addr, pri->name);
173	}
174	else {
175		err = os_set_slip(sfd);
176		if (err < 0) {
177			printk(UM_KERN_ERR "Failed to set slip discipline "
178			       "encapsulation - err = %d\n", -err);
179			goto out_close2;
180		}
181	}
182	return mfd;
183out_close2:
184	close(sfd);
185out_close:
186	close(mfd);
187out:
188	return err;
189}
190
191static void slip_close(int fd, void *data)
192{
193	struct slip_data *pri = data;
194	char version_buf[sizeof("nnnnn\0")];
195	char *argv[] = { "uml_net", version_buf, "slip", "down", pri->name,
196			 NULL };
197	int err;
198
199	if (pri->gate_addr != NULL)
200		iter_addresses(pri->dev, close_addr, pri->name);
201
202	sprintf(version_buf, "%d", UML_NET_VERSION);
203
204	err = slip_tramp(argv, pri->slave);
205
206	if (err != 0)
207		printk(UM_KERN_ERR "slip_tramp failed - errno = %d\n", -err);
208	close(fd);
209	close(pri->slave);
210	pri->slave = -1;
211}
212
213int slip_user_read(int fd, void *buf, int len, struct slip_data *pri)
214{
215	return slip_proto_read(fd, buf, len, &pri->slip);
216}
217
218int slip_user_write(int fd, void *buf, int len, struct slip_data *pri)
219{
220	return slip_proto_write(fd, buf, len, &pri->slip);
221}
222
223static void slip_add_addr(unsigned char *addr, unsigned char *netmask,
224			  void *data)
225{
226	struct slip_data *pri = data;
227
228	if (pri->slave < 0)
229		return;
230	open_addr(addr, netmask, pri->name);
231}
232
233static void slip_del_addr(unsigned char *addr, unsigned char *netmask,
234			    void *data)
235{
236	struct slip_data *pri = data;
237
238	if (pri->slave < 0)
239		return;
240	close_addr(addr, netmask, pri->name);
241}
242
243const struct net_user_info slip_user_info = {
244	.init		= slip_user_init,
245	.open		= slip_open,
246	.close	 	= slip_close,
247	.remove	 	= NULL,
248	.add_address	= slip_add_addr,
249	.delete_address = slip_del_addr,
250	.mtu		= BUF_SIZE,
251	.max_packet	= BUF_SIZE,
252};
253