1/*
2 * Copyright (C) 2001, 2002 Jeff Dike (jdike@karaya.com)
3 * Licensed under the GPL
4 */
5
6#include <stdio.h>
7#include <stddef.h>
8#include <stdlib.h>
9#include <unistd.h>
10#include <errno.h>
11#include <sys/wait.h>
12#include <sys/socket.h>
13#include <sys/un.h>
14#include <sys/uio.h>
15#include <sys/ioctl.h>
16#include <net/if.h>
17#include <linux/if_tun.h>
18#include "net_user.h"
19#include "tuntap.h"
20#include "kern_util.h"
21#include "user.h"
22#include "os.h"
23
24#define MAX_PACKET ETH_MAX_PACKET
25
26static int tuntap_user_init(void *data, void *dev)
27{
28	struct tuntap_data *pri = data;
29
30	pri->dev = dev;
31	return 0;
32}
33
34static void tuntap_add_addr(unsigned char *addr, unsigned char *netmask,
35			    void *data)
36{
37	struct tuntap_data *pri = data;
38
39	tap_check_ips(pri->gate_addr, addr);
40	if((pri->fd == -1) || pri->fixed_config)
41		return;
42	open_addr(addr, netmask, pri->dev_name);
43}
44
45static void tuntap_del_addr(unsigned char *addr, unsigned char *netmask,
46			    void *data)
47{
48	struct tuntap_data *pri = data;
49
50	if((pri->fd == -1) || pri->fixed_config)
51		return;
52	close_addr(addr, netmask, pri->dev_name);
53}
54
55struct tuntap_pre_exec_data {
56	int stdout;
57	int close_me;
58};
59
60static void tuntap_pre_exec(void *arg)
61{
62	struct tuntap_pre_exec_data *data = arg;
63
64	dup2(data->stdout, 1);
65	os_close_file(data->close_me);
66}
67
68static int tuntap_open_tramp(char *gate, int *fd_out, int me, int remote,
69			     char *buffer, int buffer_len, int *used_out)
70{
71	struct tuntap_pre_exec_data data;
72	char version_buf[sizeof("nnnnn\0")];
73	char *argv[] = { "uml_net", version_buf, "tuntap", "up", gate,
74			 NULL };
75	char buf[CMSG_SPACE(sizeof(*fd_out))];
76	struct msghdr msg;
77	struct cmsghdr *cmsg;
78	struct iovec iov;
79	int pid, n, err;
80
81	sprintf(version_buf, "%d", UML_NET_VERSION);
82
83	data.stdout = remote;
84	data.close_me = me;
85
86	pid = run_helper(tuntap_pre_exec, &data, argv, NULL);
87
88	if(pid < 0)
89		return -pid;
90
91	os_close_file(remote);
92
93	msg.msg_name = NULL;
94	msg.msg_namelen = 0;
95	if(buffer != NULL){
96		iov = ((struct iovec) { buffer, buffer_len });
97		msg.msg_iov = &iov;
98		msg.msg_iovlen = 1;
99	}
100	else {
101		msg.msg_iov = NULL;
102		msg.msg_iovlen = 0;
103	}
104	msg.msg_control = buf;
105	msg.msg_controllen = sizeof(buf);
106	msg.msg_flags = 0;
107	n = recvmsg(me, &msg, 0);
108	*used_out = n;
109	if(n < 0){
110		err = -errno;
111		printk("tuntap_open_tramp : recvmsg failed - errno = %d\n",
112		       errno);
113		return err;
114	}
115	CATCH_EINTR(waitpid(pid, NULL, 0));
116
117	cmsg = CMSG_FIRSTHDR(&msg);
118	if(cmsg == NULL){
119		printk("tuntap_open_tramp : didn't receive a message\n");
120		return -EINVAL;
121	}
122	if((cmsg->cmsg_level != SOL_SOCKET) ||
123	   (cmsg->cmsg_type != SCM_RIGHTS)){
124		printk("tuntap_open_tramp : didn't receive a descriptor\n");
125		return -EINVAL;
126	}
127	*fd_out = ((int *) CMSG_DATA(cmsg))[0];
128	os_set_exec_close(*fd_out, 1);
129	return 0;
130}
131
132static int tuntap_open(void *data)
133{
134	struct ifreq ifr;
135	struct tuntap_data *pri = data;
136	char *output, *buffer;
137	int err, fds[2], len, used;
138
139	err = tap_open_common(pri->dev, pri->gate_addr);
140	if(err < 0)
141		return err;
142
143	if(pri->fixed_config){
144		pri->fd = os_open_file("/dev/net/tun",
145				       of_cloexec(of_rdwr(OPENFLAGS())), 0);
146		if(pri->fd < 0){
147			printk("Failed to open /dev/net/tun, err = %d\n",
148			       -pri->fd);
149			return pri->fd;
150		}
151		memset(&ifr, 0, sizeof(ifr));
152		ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
153		strlcpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name));
154		if(ioctl(pri->fd, TUNSETIFF, (void *) &ifr) < 0){
155			err = -errno;
156			printk("TUNSETIFF failed, errno = %d\n", errno);
157			os_close_file(pri->fd);
158			return err;
159		}
160	}
161	else {
162		err = os_pipe(fds, 0, 0);
163		if(err < 0){
164			printk("tuntap_open : os_pipe failed - err = %d\n",
165			       -err);
166			return err;
167		}
168
169		buffer = get_output_buffer(&len);
170		if(buffer != NULL) len--;
171		used = 0;
172
173		err = tuntap_open_tramp(pri->gate_addr, &pri->fd, fds[0],
174					fds[1], buffer, len, &used);
175
176		output = buffer;
177		if(err < 0) {
178			printk("%s", output);
179			free_output_buffer(buffer);
180			printk("tuntap_open_tramp failed - err = %d\n", -err);
181			return err;
182		}
183
184		pri->dev_name = uml_strdup(buffer);
185		output += IFNAMSIZ;
186		printk("%s", output);
187		free_output_buffer(buffer);
188
189		os_close_file(fds[0]);
190		iter_addresses(pri->dev, open_addr, pri->dev_name);
191	}
192
193	return pri->fd;
194}
195
196static void tuntap_close(int fd, void *data)
197{
198	struct tuntap_data *pri = data;
199
200	if(!pri->fixed_config)
201		iter_addresses(pri->dev, close_addr, pri->dev_name);
202	os_close_file(fd);
203	pri->fd = -1;
204}
205
206static int tuntap_set_mtu(int mtu, void *data)
207{
208	return mtu;
209}
210
211const struct net_user_info tuntap_user_info = {
212	.init		= tuntap_user_init,
213	.open		= tuntap_open,
214	.close	 	= tuntap_close,
215	.remove	 	= NULL,
216	.set_mtu	= tuntap_set_mtu,
217	.add_address	= tuntap_add_addr,
218	.delete_address = tuntap_del_addr,
219	.max_packet	= MAX_PACKET
220};
221