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