xref: /openbmc/linux/arch/um/drivers/slip_user.c (revision 96de0e252cedffad61b3cb5e05662c591898e69a)
1 /*
2  * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3  * Licensed under the GPL.
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 <sys/termios.h>
13 #include <sys/wait.h>
14 #include "kern_constants.h"
15 #include "net_user.h"
16 #include "os.h"
17 #include "slip.h"
18 #include "um_malloc.h"
19 #include "user.h"
20 
21 static int slip_user_init(void *data, void *dev)
22 {
23 	struct slip_data *pri = data;
24 
25 	pri->dev = dev;
26 	return 0;
27 }
28 
29 static int set_up_tty(int fd)
30 {
31 	int i;
32 	struct termios tios;
33 
34 	if (tcgetattr(fd, &tios) < 0) {
35 		printk(UM_KERN_ERR "could not get initial terminal "
36 		       "attributes\n");
37 		return -1;
38 	}
39 
40 	tios.c_cflag = CS8 | CREAD | HUPCL | CLOCAL;
41 	tios.c_iflag = IGNBRK | IGNPAR;
42 	tios.c_oflag = 0;
43 	tios.c_lflag = 0;
44 	for (i = 0; i < NCCS; i++)
45 		tios.c_cc[i] = 0;
46 	tios.c_cc[VMIN] = 1;
47 	tios.c_cc[VTIME] = 0;
48 
49 	cfsetospeed(&tios, B38400);
50 	cfsetispeed(&tios, B38400);
51 
52 	if (tcsetattr(fd, TCSAFLUSH, &tios) < 0) {
53 		printk(UM_KERN_ERR "failed to set terminal attributes\n");
54 		return -1;
55 	}
56 	return 0;
57 }
58 
59 struct slip_pre_exec_data {
60 	int stdin;
61 	int stdout;
62 	int close_me;
63 };
64 
65 static void slip_pre_exec(void *arg)
66 {
67 	struct slip_pre_exec_data *data = arg;
68 
69 	if (data->stdin >= 0)
70 		dup2(data->stdin, 0);
71 	dup2(data->stdout, 1);
72 	if (data->close_me >= 0)
73 		close(data->close_me);
74 }
75 
76 static int slip_tramp(char **argv, int fd)
77 {
78 	struct slip_pre_exec_data pe_data;
79 	char *output;
80 	int status, pid, fds[2], err, output_len;
81 
82 	err = os_pipe(fds, 1, 0);
83 	if (err < 0) {
84 		printk(UM_KERN_ERR "slip_tramp : pipe failed, err = %d\n",
85 		       -err);
86 		goto out;
87 	}
88 
89 	err = 0;
90 	pe_data.stdin = fd;
91 	pe_data.stdout = fds[1];
92 	pe_data.close_me = fds[0];
93 	err = run_helper(slip_pre_exec, &pe_data, argv);
94 	if (err < 0)
95 		goto out_close;
96 	pid = err;
97 
98 	output_len = UM_KERN_PAGE_SIZE;
99 	output = kmalloc(output_len, UM_GFP_KERNEL);
100 	if (output == NULL) {
101 		printk(UM_KERN_ERR "slip_tramp : failed to allocate output "
102 		       "buffer\n");
103 		os_kill_process(pid, 1);
104 		err = -ENOMEM;
105 		goto out_free;
106 	}
107 
108 	close(fds[1]);
109 	read_output(fds[0], output, output_len);
110 	printk("%s", output);
111 
112 	CATCH_EINTR(err = waitpid(pid, &status, 0));
113 	if (err < 0)
114 		err = errno;
115 	else if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0)) {
116 		printk(UM_KERN_ERR "'%s' didn't exit with status 0\n", argv[0]);
117 		err = -EINVAL;
118 	}
119 	else err = 0;
120 
121 	close(fds[0]);
122 
123 out_free:
124 	kfree(output);
125 	return err;
126 
127 out_close:
128 	close(fds[0]);
129 	close(fds[1]);
130 out:
131 	return err;
132 }
133 
134 static int slip_open(void *data)
135 {
136 	struct slip_data *pri = data;
137 	char version_buf[sizeof("nnnnn\0")];
138 	char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
139 	char *argv[] = { "uml_net", version_buf, "slip", "up", gate_buf,
140 			 NULL };
141 	int sfd, mfd, err;
142 
143 	err = get_pty();
144 	if (err < 0) {
145 		printk(UM_KERN_ERR "slip-open : Failed to open pty, err = %d\n",
146 		       -err);
147 		goto out;
148 	}
149 	mfd = err;
150 
151 	err = open(ptsname(mfd), O_RDWR, 0);
152 	if (err < 0) {
153 		printk(UM_KERN_ERR "Couldn't open tty for slip line, "
154 		       "err = %d\n", -err);
155 		goto out_close;
156 	}
157 	sfd = err;
158 
159 	if (set_up_tty(sfd))
160 		goto out_close2;
161 
162 	pri->slave = sfd;
163 	pri->slip.pos = 0;
164 	pri->slip.esc = 0;
165 	if (pri->gate_addr != NULL) {
166 		sprintf(version_buf, "%d", UML_NET_VERSION);
167 		strcpy(gate_buf, pri->gate_addr);
168 
169 		err = slip_tramp(argv, sfd);
170 
171 		if (err < 0) {
172 			printk(UM_KERN_ERR "slip_tramp failed - err = %d\n",
173 			       -err);
174 			goto out_close2;
175 		}
176 		err = os_get_ifname(pri->slave, pri->name);
177 		if (err < 0) {
178 			printk(UM_KERN_ERR "get_ifname failed, err = %d\n",
179 			       -err);
180 			goto out_close2;
181 		}
182 		iter_addresses(pri->dev, open_addr, pri->name);
183 	}
184 	else {
185 		err = os_set_slip(sfd);
186 		if (err < 0) {
187 			printk(UM_KERN_ERR "Failed to set slip discipline "
188 			       "encapsulation - err = %d\n", -err);
189 			goto out_close2;
190 		}
191 	}
192 	return mfd;
193 out_close2:
194 	close(sfd);
195 out_close:
196 	close(mfd);
197 out:
198 	return err;
199 }
200 
201 static void slip_close(int fd, void *data)
202 {
203 	struct slip_data *pri = data;
204 	char version_buf[sizeof("nnnnn\0")];
205 	char *argv[] = { "uml_net", version_buf, "slip", "down", pri->name,
206 			 NULL };
207 	int err;
208 
209 	if (pri->gate_addr != NULL)
210 		iter_addresses(pri->dev, close_addr, pri->name);
211 
212 	sprintf(version_buf, "%d", UML_NET_VERSION);
213 
214 	err = slip_tramp(argv, pri->slave);
215 
216 	if (err != 0)
217 		printk(UM_KERN_ERR "slip_tramp failed - errno = %d\n", -err);
218 	close(fd);
219 	close(pri->slave);
220 	pri->slave = -1;
221 }
222 
223 int slip_user_read(int fd, void *buf, int len, struct slip_data *pri)
224 {
225 	return slip_proto_read(fd, buf, len, &pri->slip);
226 }
227 
228 int slip_user_write(int fd, void *buf, int len, struct slip_data *pri)
229 {
230 	return slip_proto_write(fd, buf, len, &pri->slip);
231 }
232 
233 static void slip_add_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 	open_addr(addr, netmask, pri->name);
241 }
242 
243 static void slip_del_addr(unsigned char *addr, unsigned char *netmask,
244 			    void *data)
245 {
246 	struct slip_data *pri = data;
247 
248 	if (pri->slave < 0)
249 		return;
250 	close_addr(addr, netmask, pri->name);
251 }
252 
253 const struct net_user_info slip_user_info = {
254 	.init		= slip_user_init,
255 	.open		= slip_open,
256 	.close	 	= slip_close,
257 	.remove	 	= NULL,
258 	.add_address	= slip_add_addr,
259 	.delete_address = slip_del_addr,
260 	.mtu		= BUF_SIZE,
261 	.max_packet	= BUF_SIZE,
262 };
263