xref: /openbmc/linux/arch/um/drivers/slip_user.c (revision 5f5bac82)
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 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 = uml_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 	err = helper_wait(pid);
113 	close(fds[0]);
114 
115 out_free:
116 	kfree(output);
117 	return err;
118 
119 out_close:
120 	close(fds[0]);
121 	close(fds[1]);
122 out:
123 	return err;
124 }
125 
126 static int slip_open(void *data)
127 {
128 	struct slip_data *pri = data;
129 	char version_buf[sizeof("nnnnn\0")];
130 	char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
131 	char *argv[] = { "uml_net", version_buf, "slip", "up", gate_buf,
132 			 NULL };
133 	int sfd, mfd, err;
134 
135 	err = get_pty();
136 	if (err < 0) {
137 		printk(UM_KERN_ERR "slip-open : Failed to open pty, err = %d\n",
138 		       -err);
139 		goto out;
140 	}
141 	mfd = err;
142 
143 	err = open(ptsname(mfd), O_RDWR, 0);
144 	if (err < 0) {
145 		printk(UM_KERN_ERR "Couldn't open tty for slip line, "
146 		       "err = %d\n", -err);
147 		goto out_close;
148 	}
149 	sfd = err;
150 
151 	if (set_up_tty(sfd))
152 		goto out_close2;
153 
154 	pri->slave = sfd;
155 	pri->slip.pos = 0;
156 	pri->slip.esc = 0;
157 	if (pri->gate_addr != NULL) {
158 		sprintf(version_buf, "%d", UML_NET_VERSION);
159 		strcpy(gate_buf, pri->gate_addr);
160 
161 		err = slip_tramp(argv, sfd);
162 
163 		if (err < 0) {
164 			printk(UM_KERN_ERR "slip_tramp failed - err = %d\n",
165 			       -err);
166 			goto out_close2;
167 		}
168 		err = os_get_ifname(pri->slave, pri->name);
169 		if (err < 0) {
170 			printk(UM_KERN_ERR "get_ifname failed, err = %d\n",
171 			       -err);
172 			goto out_close2;
173 		}
174 		iter_addresses(pri->dev, open_addr, pri->name);
175 	}
176 	else {
177 		err = os_set_slip(sfd);
178 		if (err < 0) {
179 			printk(UM_KERN_ERR "Failed to set slip discipline "
180 			       "encapsulation - err = %d\n", -err);
181 			goto out_close2;
182 		}
183 	}
184 	return mfd;
185 out_close2:
186 	close(sfd);
187 out_close:
188 	close(mfd);
189 out:
190 	return err;
191 }
192 
193 static void slip_close(int fd, void *data)
194 {
195 	struct slip_data *pri = data;
196 	char version_buf[sizeof("nnnnn\0")];
197 	char *argv[] = { "uml_net", version_buf, "slip", "down", pri->name,
198 			 NULL };
199 	int err;
200 
201 	if (pri->gate_addr != NULL)
202 		iter_addresses(pri->dev, close_addr, pri->name);
203 
204 	sprintf(version_buf, "%d", UML_NET_VERSION);
205 
206 	err = slip_tramp(argv, pri->slave);
207 
208 	if (err != 0)
209 		printk(UM_KERN_ERR "slip_tramp failed - errno = %d\n", -err);
210 	close(fd);
211 	close(pri->slave);
212 	pri->slave = -1;
213 }
214 
215 int slip_user_read(int fd, void *buf, int len, struct slip_data *pri)
216 {
217 	return slip_proto_read(fd, buf, len, &pri->slip);
218 }
219 
220 int slip_user_write(int fd, void *buf, int len, struct slip_data *pri)
221 {
222 	return slip_proto_write(fd, buf, len, &pri->slip);
223 }
224 
225 static void slip_add_addr(unsigned char *addr, unsigned char *netmask,
226 			  void *data)
227 {
228 	struct slip_data *pri = data;
229 
230 	if (pri->slave < 0)
231 		return;
232 	open_addr(addr, netmask, pri->name);
233 }
234 
235 static void slip_del_addr(unsigned char *addr, unsigned char *netmask,
236 			    void *data)
237 {
238 	struct slip_data *pri = data;
239 
240 	if (pri->slave < 0)
241 		return;
242 	close_addr(addr, netmask, pri->name);
243 }
244 
245 const struct net_user_info slip_user_info = {
246 	.init		= slip_user_init,
247 	.open		= slip_open,
248 	.close	 	= slip_close,
249 	.remove	 	= NULL,
250 	.add_address	= slip_add_addr,
251 	.delete_address = slip_del_addr,
252 	.mtu		= BUF_SIZE,
253 	.max_packet	= BUF_SIZE,
254 };
255