xref: /openbmc/linux/arch/um/drivers/slip_user.c (revision 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2)
1 #include <stdio.h>
2 #include <stdlib.h>
3 #include <unistd.h>
4 #include <stddef.h>
5 #include <sched.h>
6 #include <string.h>
7 #include <errno.h>
8 #include <sys/termios.h>
9 #include <sys/wait.h>
10 #include <sys/signal.h>
11 #include "user_util.h"
12 #include "kern_util.h"
13 #include "user.h"
14 #include "net_user.h"
15 #include "slip.h"
16 #include "slip_proto.h"
17 #include "helper.h"
18 #include "os.h"
19 
20 void slip_user_init(void *data, void *dev)
21 {
22 	struct slip_data *pri = data;
23 
24 	pri->dev = dev;
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("could not get initial terminal attributes\n");
34 		return(-1);
35 	}
36 
37 	tios.c_cflag = CS8 | CREAD | HUPCL | CLOCAL;
38 	tios.c_iflag = IGNBRK | IGNPAR;
39 	tios.c_oflag = 0;
40 	tios.c_lflag = 0;
41 	for (i = 0; i < NCCS; i++)
42 		tios.c_cc[i] = 0;
43 	tios.c_cc[VMIN] = 1;
44 	tios.c_cc[VTIME] = 0;
45 
46 	cfsetospeed(&tios, B38400);
47 	cfsetispeed(&tios, B38400);
48 
49 	if (tcsetattr(fd, TCSAFLUSH, &tios) < 0) {
50 		printk("failed to set terminal attributes\n");
51 		return(-1);
52 	}
53 	return(0);
54 }
55 
56 struct slip_pre_exec_data {
57 	int stdin;
58 	int stdout;
59 	int close_me;
60 };
61 
62 static void slip_pre_exec(void *arg)
63 {
64 	struct slip_pre_exec_data *data = arg;
65 
66 	if(data->stdin >= 0) dup2(data->stdin, 0);
67 	dup2(data->stdout, 1);
68 	if(data->close_me >= 0) os_close_file(data->close_me);
69 }
70 
71 static int slip_tramp(char **argv, int fd)
72 {
73 	struct slip_pre_exec_data pe_data;
74 	char *output;
75 	int status, pid, fds[2], err, output_len;
76 
77 	err = os_pipe(fds, 1, 0);
78 	if(err < 0){
79 		printk("slip_tramp : pipe failed, err = %d\n", -err);
80 		return(err);
81 	}
82 
83 	err = 0;
84 	pe_data.stdin = fd;
85 	pe_data.stdout = fds[1];
86 	pe_data.close_me = fds[0];
87 	pid = run_helper(slip_pre_exec, &pe_data, argv, NULL);
88 
89 	if(pid < 0) err = pid;
90 	else {
91 		output_len = page_size();
92 		output = um_kmalloc(output_len);
93 		if(output == NULL)
94 			printk("slip_tramp : failed to allocate output "
95 			       "buffer\n");
96 
97 		os_close_file(fds[1]);
98 		read_output(fds[0], output, output_len);
99 		if(output != NULL){
100 			printk("%s", output);
101 			kfree(output);
102 		}
103 		CATCH_EINTR(err = waitpid(pid, &status, 0));
104 		if(err < 0)
105 			err = errno;
106 		else if(!WIFEXITED(status) || (WEXITSTATUS(status) != 0)){
107 			printk("'%s' didn't exit with status 0\n", argv[0]);
108 			err = -EINVAL;
109 		}
110 	}
111 
112 	os_close_file(fds[0]);
113 
114 	return(err);
115 }
116 
117 static int slip_open(void *data)
118 {
119 	struct slip_data *pri = data;
120 	char version_buf[sizeof("nnnnn\0")];
121 	char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
122 	char *argv[] = { "uml_net", version_buf, "slip", "up", gate_buf,
123 			 NULL };
124 	int sfd, mfd, err;
125 
126 	mfd = get_pty();
127 	if(mfd < 0){
128 		printk("umn : Failed to open pty, err = %d\n", -mfd);
129 		return(mfd);
130 	}
131 	sfd = os_open_file(ptsname(mfd), of_rdwr(OPENFLAGS()), 0);
132 	if(sfd < 0){
133 		printk("Couldn't open tty for slip line, err = %d\n", -sfd);
134 		os_close_file(mfd);
135 		return(sfd);
136 	}
137 	if(set_up_tty(sfd)) return(-1);
138 	pri->slave = sfd;
139 	pri->pos = 0;
140 	pri->esc = 0;
141 	if(pri->gate_addr != NULL){
142 		sprintf(version_buf, "%d", UML_NET_VERSION);
143 		strcpy(gate_buf, pri->gate_addr);
144 
145 		err = slip_tramp(argv, sfd);
146 
147 		if(err < 0){
148 			printk("slip_tramp failed - err = %d\n", -err);
149 			return(err);
150 		}
151 		err = os_get_ifname(pri->slave, pri->name);
152 		if(err < 0){
153 			printk("get_ifname failed, err = %d\n", -err);
154 			return(err);
155 		}
156 		iter_addresses(pri->dev, open_addr, pri->name);
157 	}
158 	else {
159 		err = os_set_slip(sfd);
160 		if(err < 0){
161 			printk("Failed to set slip discipline encapsulation - "
162 			       "err = %d\n", -err);
163 			return(err);
164 		}
165 	}
166 	return(mfd);
167 }
168 
169 static void slip_close(int fd, void *data)
170 {
171 	struct slip_data *pri = data;
172 	char version_buf[sizeof("nnnnn\0")];
173 	char *argv[] = { "uml_net", version_buf, "slip", "down", pri->name,
174 			 NULL };
175 	int err;
176 
177 	if(pri->gate_addr != NULL)
178 		iter_addresses(pri->dev, close_addr, pri->name);
179 
180 	sprintf(version_buf, "%d", UML_NET_VERSION);
181 
182 	err = slip_tramp(argv, pri->slave);
183 
184 	if(err != 0)
185 		printk("slip_tramp failed - errno = %d\n", -err);
186 	os_close_file(fd);
187 	os_close_file(pri->slave);
188 	pri->slave = -1;
189 }
190 
191 int slip_user_read(int fd, void *buf, int len, struct slip_data *pri)
192 {
193 	int i, n, size, start;
194 
195 	if(pri->more>0) {
196 		i = 0;
197 		while(i < pri->more) {
198 			size = slip_unesc(pri->ibuf[i++],
199 					pri->ibuf, &pri->pos, &pri->esc);
200 			if(size){
201 				memcpy(buf, pri->ibuf, size);
202 				memmove(pri->ibuf, &pri->ibuf[i], pri->more-i);
203 				pri->more=pri->more-i;
204 				return(size);
205 			}
206 		}
207 		pri->more=0;
208 	}
209 
210 	n = net_read(fd, &pri->ibuf[pri->pos], sizeof(pri->ibuf) - pri->pos);
211 	if(n <= 0) return(n);
212 
213 	start = pri->pos;
214 	for(i = 0; i < n; i++){
215 		size = slip_unesc(pri->ibuf[start + i],
216 				pri->ibuf, &pri->pos, &pri->esc);
217 		if(size){
218 			memcpy(buf, pri->ibuf, size);
219 			memmove(pri->ibuf, &pri->ibuf[start+i+1], n-(i+1));
220 			pri->more=n-(i+1);
221 			return(size);
222 		}
223 	}
224 	return(0);
225 }
226 
227 int slip_user_write(int fd, void *buf, int len, struct slip_data *pri)
228 {
229 	int actual, n;
230 
231 	actual = slip_esc(buf, pri->obuf, len);
232 	n = net_write(fd, pri->obuf, actual);
233 	if(n < 0) return(n);
234 	else return(len);
235 }
236 
237 static int slip_set_mtu(int mtu, void *data)
238 {
239 	return(mtu);
240 }
241 
242 static void slip_add_addr(unsigned char *addr, unsigned char *netmask,
243 			  void *data)
244 {
245 	struct slip_data *pri = data;
246 
247 	if(pri->slave < 0) return;
248 	open_addr(addr, netmask, pri->name);
249 }
250 
251 static void slip_del_addr(unsigned char *addr, unsigned char *netmask,
252 			    void *data)
253 {
254 	struct slip_data *pri = data;
255 
256 	if(pri->slave < 0) return;
257 	close_addr(addr, netmask, pri->name);
258 }
259 
260 struct net_user_info slip_user_info = {
261 	.init		= slip_user_init,
262 	.open		= slip_open,
263 	.close	 	= slip_close,
264 	.remove	 	= NULL,
265 	.set_mtu	= slip_set_mtu,
266 	.add_address	= slip_add_addr,
267 	.delete_address = slip_del_addr,
268 	.max_packet	= BUF_SIZE
269 };
270 
271 /*
272  * Overrides for Emacs so that we follow Linus's tabbing style.
273  * Emacs will notice this stuff at the end of the file and automatically
274  * adjust the settings for this buffer only.  This must remain at the end
275  * of the file.
276  * ---------------------------------------------------------------------------
277  * Local variables:
278  * c-file-style: "linux"
279  * End:
280  */
281