xref: /openbmc/linux/arch/um/drivers/slip_user.c (revision c21b37f6)
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 "kern_util.h"
12 #include "user.h"
13 #include "net_user.h"
14 #include "slip.h"
15 #include "slip_common.h"
16 #include "os.h"
17 #include "um_malloc.h"
18 #include "kern_constants.h"
19 
20 static int slip_user_init(void *data, void *dev)
21 {
22 	struct slip_data *pri = data;
23 
24 	pri->dev = dev;
25 	return 0;
26 }
27 
28 static int set_up_tty(int fd)
29 {
30 	int i;
31 	struct termios tios;
32 
33 	if (tcgetattr(fd, &tios) < 0) {
34 		printk("could not get initial terminal 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("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) dup2(data->stdin, 0);
68 	dup2(data->stdout, 1);
69 	if(data->close_me >= 0) os_close_file(data->close_me);
70 }
71 
72 static int slip_tramp(char **argv, int fd)
73 {
74 	struct slip_pre_exec_data pe_data;
75 	char *output;
76 	int status, pid, fds[2], err, output_len;
77 
78 	err = os_pipe(fds, 1, 0);
79 	if(err < 0){
80 		printk("slip_tramp : pipe failed, err = %d\n", -err);
81 		goto out;
82 	}
83 
84 	err = 0;
85 	pe_data.stdin = fd;
86 	pe_data.stdout = fds[1];
87 	pe_data.close_me = fds[0];
88 	err = run_helper(slip_pre_exec, &pe_data, argv);
89 	if(err < 0)
90 		goto out_close;
91 	pid = err;
92 
93 	output_len = UM_KERN_PAGE_SIZE;
94 	output = kmalloc(output_len, UM_GFP_KERNEL);
95 	if(output == NULL){
96 		printk("slip_tramp : failed to allocate output buffer\n");
97 		os_kill_process(pid, 1);
98 		err = -ENOMEM;
99 		goto out_free;
100 	}
101 
102 	os_close_file(fds[1]);
103 	read_output(fds[0], output, output_len);
104 	printk("%s", output);
105 
106 	CATCH_EINTR(err = waitpid(pid, &status, 0));
107 	if(err < 0)
108 		err = errno;
109 	else if(!WIFEXITED(status) || (WEXITSTATUS(status) != 0)){
110 		printk("'%s' didn't exit with status 0\n", argv[0]);
111 		err = -EINVAL;
112 	}
113 	else err = 0;
114 
115 	os_close_file(fds[0]);
116 
117 out_free:
118 	kfree(output);
119 	return err;
120 
121 out_close:
122 	os_close_file(fds[0]);
123 	os_close_file(fds[1]);
124 out:
125 	return err;
126 }
127 
128 static int slip_open(void *data)
129 {
130 	struct slip_data *pri = data;
131 	char version_buf[sizeof("nnnnn\0")];
132 	char gate_buf[sizeof("nnn.nnn.nnn.nnn\0")];
133 	char *argv[] = { "uml_net", version_buf, "slip", "up", gate_buf,
134 			 NULL };
135 	int sfd, mfd, err;
136 
137 	err = get_pty();
138 	if(err < 0){
139 		printk("slip-open : Failed to open pty, err = %d\n", -err);
140 		goto out;
141 	}
142 	mfd = err;
143 
144 	err = os_open_file(ptsname(mfd), of_rdwr(OPENFLAGS()), 0);
145 	if(err < 0){
146 		printk("Couldn't open tty for slip line, 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("slip_tramp failed - err = %d\n", -err);
165 			goto out_close2;
166 		}
167 		err = os_get_ifname(pri->slave, pri->name);
168 		if(err < 0){
169 			printk("get_ifname failed, err = %d\n", -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("Failed to set slip discipline encapsulation - "
178 			       "err = %d\n", -err);
179 			goto out_close2;
180 		}
181 	}
182 	return(mfd);
183 out_close2:
184 	os_close_file(sfd);
185 out_close:
186 	os_close_file(mfd);
187 out:
188 	return err;
189 }
190 
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("slip_tramp failed - errno = %d\n", -err);
208 	os_close_file(fd);
209 	os_close_file(pri->slave);
210 	pri->slave = -1;
211 }
212 
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 
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 
223 static int slip_set_mtu(int mtu, void *data)
224 {
225 	return(mtu);
226 }
227 
228 static void slip_add_addr(unsigned char *addr, unsigned char *netmask,
229 			  void *data)
230 {
231 	struct slip_data *pri = data;
232 
233 	if(pri->slave < 0) return;
234 	open_addr(addr, netmask, pri->name);
235 }
236 
237 static void slip_del_addr(unsigned char *addr, unsigned char *netmask,
238 			    void *data)
239 {
240 	struct slip_data *pri = data;
241 
242 	if(pri->slave < 0) return;
243 	close_addr(addr, netmask, pri->name);
244 }
245 
246 const struct net_user_info slip_user_info = {
247 	.init		= slip_user_init,
248 	.open		= slip_open,
249 	.close	 	= slip_close,
250 	.remove	 	= NULL,
251 	.set_mtu	= slip_set_mtu,
252 	.add_address	= slip_add_addr,
253 	.delete_address = slip_del_addr,
254 	.max_packet	= BUF_SIZE
255 };
256