xref: /linux/arch/um/drivers/slirp_user.c (revision 60e13231561b3a4c5269bfa1ef6c0569ad6f28ec)
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 "kern_constants.h"
11 #include "net_user.h"
12 #include "os.h"
13 #include "slirp.h"
14 #include "user.h"
15 
16 static int slirp_user_init(void *data, void *dev)
17 {
18 	struct slirp_data *pri = data;
19 
20 	pri->dev = dev;
21 	return 0;
22 }
23 
24 struct slirp_pre_exec_data {
25 	int stdin;
26 	int stdout;
27 };
28 
29 static void slirp_pre_exec(void *arg)
30 {
31 	struct slirp_pre_exec_data *data = arg;
32 
33 	if (data->stdin != -1)
34 		dup2(data->stdin, 0);
35 	if (data->stdout != -1)
36 		dup2(data->stdout, 1);
37 }
38 
39 static int slirp_tramp(char **argv, int fd)
40 {
41 	struct slirp_pre_exec_data pe_data;
42 	int pid;
43 
44 	pe_data.stdin = fd;
45 	pe_data.stdout = fd;
46 	pid = run_helper(slirp_pre_exec, &pe_data, argv);
47 
48 	return pid;
49 }
50 
51 static int slirp_open(void *data)
52 {
53 	struct slirp_data *pri = data;
54 	int fds[2], pid, err;
55 
56 	err = os_pipe(fds, 1, 1);
57 	if (err)
58 		return err;
59 
60 	err = slirp_tramp(pri->argw.argv, fds[1]);
61 	if (err < 0) {
62 		printk(UM_KERN_ERR "slirp_tramp failed - errno = %d\n", -err);
63 		goto out;
64 	}
65 	pid = err;
66 
67 	pri->slave = fds[1];
68 	pri->slip.pos = 0;
69 	pri->slip.esc = 0;
70 	pri->pid = err;
71 
72 	return fds[0];
73 out:
74 	close(fds[0]);
75 	close(fds[1]);
76 	return err;
77 }
78 
79 static void slirp_close(int fd, void *data)
80 {
81 	struct slirp_data *pri = data;
82 	int err;
83 
84 	close(fd);
85 	close(pri->slave);
86 
87 	pri->slave = -1;
88 
89 	if (pri->pid<1) {
90 		printk(UM_KERN_ERR "slirp_close: no child process to shut "
91 		       "down\n");
92 		return;
93 	}
94 
95 #if 0
96 	if (kill(pri->pid, SIGHUP)<0) {
97 		printk(UM_KERN_ERR "slirp_close: sending hangup to %d failed "
98 		       "(%d)\n", pri->pid, errno);
99 	}
100 #endif
101 	err = helper_wait(pri->pid);
102 	if (err < 0)
103 		return;
104 
105 	pri->pid = -1;
106 }
107 
108 int slirp_user_read(int fd, void *buf, int len, struct slirp_data *pri)
109 {
110 	return slip_proto_read(fd, buf, len, &pri->slip);
111 }
112 
113 int slirp_user_write(int fd, void *buf, int len, struct slirp_data *pri)
114 {
115 	return slip_proto_write(fd, buf, len, &pri->slip);
116 }
117 
118 const struct net_user_info slirp_user_info = {
119 	.init		= slirp_user_init,
120 	.open		= slirp_open,
121 	.close	 	= slirp_close,
122 	.remove	 	= NULL,
123 	.add_address	= NULL,
124 	.delete_address = NULL,
125 	.mtu		= BUF_SIZE,
126 	.max_packet	= BUF_SIZE,
127 };
128