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 
slip_user_init(void * data,void * dev)19 static 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 
set_up_tty(int fd)27 static 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 
57 struct slip_pre_exec_data {
58 	int stdin_fd;
59 	int stdout_fd;
60 	int close_me;
61 };
62 
slip_pre_exec(void * arg)63 static 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 
slip_tramp(char ** argv,int fd)74 static 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 
116 out_close:
117 	close(fds[0]);
118 	close(fds[1]);
119 out:
120 	return err;
121 }
122 
slip_open(void * data)123 static 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;
183 out_close2:
184 	close(sfd);
185 out_close:
186 	close(mfd);
187 out:
188 	return err;
189 }
190 
slip_close(int fd,void * data)191 static 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 
slip_user_read(int fd,void * buf,int len,struct slip_data * pri)213 int 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 
slip_user_write(int fd,void * buf,int len,struct slip_data * pri)218 int 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 
slip_add_addr(unsigned char * addr,unsigned char * netmask,void * data)223 static 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 
slip_del_addr(unsigned char * addr,unsigned char * netmask,void * data)233 static 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 
243 const 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