xref: /openbmc/linux/arch/um/drivers/slirp_user.c (revision 275876e2)
1 /*
2  * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3  * Licensed under the GPL.
4  */
5 
6 #include <unistd.h>
7 #include <errno.h>
8 #include <string.h>
9 #include <sys/wait.h>
10 #include <net_user.h>
11 #include <os.h>
12 #include "slirp.h"
13 
14 static int slirp_user_init(void *data, void *dev)
15 {
16 	struct slirp_data *pri = data;
17 
18 	pri->dev = dev;
19 	return 0;
20 }
21 
22 struct slirp_pre_exec_data {
23 	int stdin;
24 	int stdout;
25 };
26 
27 static void slirp_pre_exec(void *arg)
28 {
29 	struct slirp_pre_exec_data *data = arg;
30 
31 	if (data->stdin != -1)
32 		dup2(data->stdin, 0);
33 	if (data->stdout != -1)
34 		dup2(data->stdout, 1);
35 }
36 
37 static int slirp_tramp(char **argv, int fd)
38 {
39 	struct slirp_pre_exec_data pe_data;
40 	int pid;
41 
42 	pe_data.stdin = fd;
43 	pe_data.stdout = fd;
44 	pid = run_helper(slirp_pre_exec, &pe_data, argv);
45 
46 	return pid;
47 }
48 
49 static int slirp_open(void *data)
50 {
51 	struct slirp_data *pri = data;
52 	int fds[2], pid, err;
53 
54 	err = os_pipe(fds, 1, 1);
55 	if (err)
56 		return err;
57 
58 	err = slirp_tramp(pri->argw.argv, fds[1]);
59 	if (err < 0) {
60 		printk(UM_KERN_ERR "slirp_tramp failed - errno = %d\n", -err);
61 		goto out;
62 	}
63 	pid = err;
64 
65 	pri->slave = fds[1];
66 	pri->slip.pos = 0;
67 	pri->slip.esc = 0;
68 	pri->pid = err;
69 
70 	return fds[0];
71 out:
72 	close(fds[0]);
73 	close(fds[1]);
74 	return err;
75 }
76 
77 static void slirp_close(int fd, void *data)
78 {
79 	struct slirp_data *pri = data;
80 	int err;
81 
82 	close(fd);
83 	close(pri->slave);
84 
85 	pri->slave = -1;
86 
87 	if (pri->pid<1) {
88 		printk(UM_KERN_ERR "slirp_close: no child process to shut "
89 		       "down\n");
90 		return;
91 	}
92 
93 #if 0
94 	if (kill(pri->pid, SIGHUP)<0) {
95 		printk(UM_KERN_ERR "slirp_close: sending hangup to %d failed "
96 		       "(%d)\n", pri->pid, errno);
97 	}
98 #endif
99 	err = helper_wait(pri->pid);
100 	if (err < 0)
101 		return;
102 
103 	pri->pid = -1;
104 }
105 
106 int slirp_user_read(int fd, void *buf, int len, struct slirp_data *pri)
107 {
108 	return slip_proto_read(fd, buf, len, &pri->slip);
109 }
110 
111 int slirp_user_write(int fd, void *buf, int len, struct slirp_data *pri)
112 {
113 	return slip_proto_write(fd, buf, len, &pri->slip);
114 }
115 
116 const struct net_user_info slirp_user_info = {
117 	.init		= slirp_user_init,
118 	.open		= slirp_open,
119 	.close	 	= slirp_close,
120 	.remove	 	= NULL,
121 	.add_address	= NULL,
122 	.delete_address = NULL,
123 	.mtu		= BUF_SIZE,
124 	.max_packet	= BUF_SIZE,
125 };
126