1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
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
14static 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
22struct slirp_pre_exec_data {
23 int stdin_fd;
24 int stdout_fd;
25};
26
27static void slirp_pre_exec(void *arg)
28{
29 struct slirp_pre_exec_data *data = arg;
30
31 if (data->stdin_fd != -1)
32 dup2(data->stdin_fd, 0);
33 if (data->stdout_fd != -1)
34 dup2(data->stdout_fd, 1);
35}
36
37static 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 = fd;
43 pe_data.stdout_fd = fd;
44 pid = run_helper(slirp_pre_exec, &pe_data, argv);
45
46 return pid;
47}
48
49static 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(argv: pri->argw.argv, fd: 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];
71out:
72 close(fds[0]);
73 close(fds[1]);
74 return err;
75}
76
77static 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
106int slirp_user_read(int fd, void *buf, int len, struct slirp_data *pri)
107{
108 return slip_proto_read(fd, buf, len, slip: &pri->slip);
109}
110
111int slirp_user_write(int fd, void *buf, int len, struct slirp_data *pri)
112{
113 return slip_proto_write(fd, buf, len, slip: &pri->slip);
114}
115
116const 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

source code of linux/arch/um/drivers/slirp_user.c