xref: /openbmc/linux/arch/um/drivers/slip_user.c (revision 827634ad)
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 <net_user.h>
15 #include <os.h>
16 #include "slip.h"
17 #include <um_malloc.h>
18 
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 
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;
59 	int stdout;
60 	int close_me;
61 };
62 
63 static void slip_pre_exec(void *arg)
64 {
65 	struct slip_pre_exec_data *data = arg;
66 
67 	if (data->stdin >= 0)
68 		dup2(data->stdin, 0);
69 	dup2(data->stdout, 1);
70 	if (data->close_me >= 0)
71 		close(data->close_me);
72 }
73 
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;
89 	pe_data.stdout = 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 
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 	if (set_up_tty(sfd))
149 		goto out_close2;
150 
151 	pri->slave = sfd;
152 	pri->slip.pos = 0;
153 	pri->slip.esc = 0;
154 	if (pri->gate_addr != NULL) {
155 		sprintf(version_buf, "%d", UML_NET_VERSION);
156 		strcpy(gate_buf, pri->gate_addr);
157 
158 		err = slip_tramp(argv, sfd);
159 
160 		if (err < 0) {
161 			printk(UM_KERN_ERR "slip_tramp failed - err = %d\n",
162 			       -err);
163 			goto out_close2;
164 		}
165 		err = os_get_ifname(pri->slave, pri->name);
166 		if (err < 0) {
167 			printk(UM_KERN_ERR "get_ifname failed, err = %d\n",
168 			       -err);
169 			goto out_close2;
170 		}
171 		iter_addresses(pri->dev, open_addr, pri->name);
172 	}
173 	else {
174 		err = os_set_slip(sfd);
175 		if (err < 0) {
176 			printk(UM_KERN_ERR "Failed to set slip discipline "
177 			       "encapsulation - err = %d\n", -err);
178 			goto out_close2;
179 		}
180 	}
181 	return mfd;
182 out_close2:
183 	close(sfd);
184 out_close:
185 	close(mfd);
186 out:
187 	return err;
188 }
189 
190 static void slip_close(int fd, void *data)
191 {
192 	struct slip_data *pri = data;
193 	char version_buf[sizeof("nnnnn\0")];
194 	char *argv[] = { "uml_net", version_buf, "slip", "down", pri->name,
195 			 NULL };
196 	int err;
197 
198 	if (pri->gate_addr != NULL)
199 		iter_addresses(pri->dev, close_addr, pri->name);
200 
201 	sprintf(version_buf, "%d", UML_NET_VERSION);
202 
203 	err = slip_tramp(argv, pri->slave);
204 
205 	if (err != 0)
206 		printk(UM_KERN_ERR "slip_tramp failed - errno = %d\n", -err);
207 	close(fd);
208 	close(pri->slave);
209 	pri->slave = -1;
210 }
211 
212 int slip_user_read(int fd, void *buf, int len, struct slip_data *pri)
213 {
214 	return slip_proto_read(fd, buf, len, &pri->slip);
215 }
216 
217 int slip_user_write(int fd, void *buf, int len, struct slip_data *pri)
218 {
219 	return slip_proto_write(fd, buf, len, &pri->slip);
220 }
221 
222 static void slip_add_addr(unsigned char *addr, unsigned char *netmask,
223 			  void *data)
224 {
225 	struct slip_data *pri = data;
226 
227 	if (pri->slave < 0)
228 		return;
229 	open_addr(addr, netmask, pri->name);
230 }
231 
232 static void slip_del_addr(unsigned char *addr, unsigned char *netmask,
233 			    void *data)
234 {
235 	struct slip_data *pri = data;
236 
237 	if (pri->slave < 0)
238 		return;
239 	close_addr(addr, netmask, pri->name);
240 }
241 
242 const struct net_user_info slip_user_info = {
243 	.init		= slip_user_init,
244 	.open		= slip_open,
245 	.close	 	= slip_close,
246 	.remove	 	= NULL,
247 	.add_address	= slip_add_addr,
248 	.delete_address = slip_del_addr,
249 	.mtu		= BUF_SIZE,
250 	.max_packet	= BUF_SIZE,
251 };
252