Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
[linux-2.6] / arch / um / os-Linux / drivers / tuntap_user.c
1 /* 
2  * Copyright (C) 2001 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
3  * Licensed under the GPL
4  */
5
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 "os.h"
18 #include "tuntap.h"
19 #include "user.h"
20
21 static int tuntap_user_init(void *data, void *dev)
22 {
23         struct tuntap_data *pri = data;
24
25         pri->dev = dev;
26         return 0;
27 }
28
29 static void tuntap_add_addr(unsigned char *addr, unsigned char *netmask,
30                             void *data)
31 {
32         struct tuntap_data *pri = data;
33
34         tap_check_ips(pri->gate_addr, addr);
35         if ((pri->fd == -1) || pri->fixed_config)
36                 return;
37         open_addr(addr, netmask, pri->dev_name);
38 }
39
40 static void tuntap_del_addr(unsigned char *addr, unsigned char *netmask,
41                             void *data)
42 {
43         struct tuntap_data *pri = data;
44
45         if ((pri->fd == -1) || pri->fixed_config)
46                 return;
47         close_addr(addr, netmask, pri->dev_name);
48 }
49
50 struct tuntap_pre_exec_data {
51         int stdout;
52         int close_me;
53 };
54
55 static void tuntap_pre_exec(void *arg)
56 {
57         struct tuntap_pre_exec_data *data = arg;
58
59         dup2(data->stdout, 1);
60         close(data->close_me);
61 }
62
63 static int tuntap_open_tramp(char *gate, int *fd_out, int me, int remote,
64                              char *buffer, int buffer_len, int *used_out)
65 {
66         struct tuntap_pre_exec_data data;
67         char version_buf[sizeof("nnnnn\0")];
68         char *argv[] = { "uml_net", version_buf, "tuntap", "up", gate,
69                          NULL };
70         char buf[CMSG_SPACE(sizeof(*fd_out))];
71         struct msghdr msg;
72         struct cmsghdr *cmsg;
73         struct iovec iov;
74         int pid, n, err;
75
76         sprintf(version_buf, "%d", UML_NET_VERSION);
77
78         data.stdout = remote;
79         data.close_me = me;
80
81         pid = run_helper(tuntap_pre_exec, &data, argv);
82
83         if (pid < 0)
84                 return -pid;
85
86         close(remote);
87
88         msg.msg_name = NULL;
89         msg.msg_namelen = 0;
90         if (buffer != NULL) {
91                 iov = ((struct iovec) { buffer, buffer_len });
92                 msg.msg_iov = &iov;
93                 msg.msg_iovlen = 1;
94         }
95         else {
96                 msg.msg_iov = NULL;
97                 msg.msg_iovlen = 0;
98         }
99         msg.msg_control = buf;
100         msg.msg_controllen = sizeof(buf);
101         msg.msg_flags = 0;
102         n = recvmsg(me, &msg, 0);
103         *used_out = n;
104         if (n < 0) {
105                 err = -errno;
106                 printk(UM_KERN_ERR "tuntap_open_tramp : recvmsg failed - "
107                        "errno = %d\n", errno);
108                 return err;
109         }
110         helper_wait(pid, 0, "tuntap_open_tramp");
111
112         cmsg = CMSG_FIRSTHDR(&msg);
113         if (cmsg == NULL) {
114                 printk(UM_KERN_ERR "tuntap_open_tramp : didn't receive a "
115                        "message\n");
116                 return -EINVAL;
117         }
118         if ((cmsg->cmsg_level != SOL_SOCKET) ||
119            (cmsg->cmsg_type != SCM_RIGHTS)) {
120                 printk(UM_KERN_ERR "tuntap_open_tramp : didn't receive a "
121                        "descriptor\n");
122                 return -EINVAL;
123         }
124         *fd_out = ((int *) CMSG_DATA(cmsg))[0];
125         os_set_exec_close(*fd_out);
126         return 0;
127 }
128
129 static int tuntap_open(void *data)
130 {
131         struct ifreq ifr;
132         struct tuntap_data *pri = data;
133         char *output, *buffer;
134         int err, fds[2], len, used;
135
136         err = tap_open_common(pri->dev, pri->gate_addr);
137         if (err < 0)
138                 return err;
139
140         if (pri->fixed_config) {
141                 pri->fd = os_open_file("/dev/net/tun",
142                                        of_cloexec(of_rdwr(OPENFLAGS())), 0);
143                 if (pri->fd < 0) {
144                         printk(UM_KERN_ERR "Failed to open /dev/net/tun, "
145                                "err = %d\n", -pri->fd);
146                         return pri->fd;
147                 }
148                 memset(&ifr, 0, sizeof(ifr));
149                 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
150                 strlcpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name));
151                 if (ioctl(pri->fd, TUNSETIFF, (void *) &ifr) < 0) {
152                         err = -errno;
153                         printk(UM_KERN_ERR "TUNSETIFF failed, errno = %d\n",
154                                errno);
155                         close(pri->fd);
156                         return err;
157                 }
158         }
159         else {
160                 err = socketpair(AF_UNIX, SOCK_DGRAM, 0, fds);
161                 if (err) {
162                         err = -errno;
163                         printk(UM_KERN_ERR "tuntap_open : socketpair failed - "
164                                "errno = %d\n", errno);
165                         return err;
166                 }
167
168                 buffer = get_output_buffer(&len);
169                 if (buffer != NULL)
170                         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(UM_KERN_ERR "tuntap_open_tramp failed - "
181                                "err = %d\n", -err);
182                         return err;
183                 }
184
185                 pri->dev_name = uml_strdup(buffer);
186                 output += IFNAMSIZ;
187                 printk("%s", output);
188                 free_output_buffer(buffer);
189
190                 close(fds[0]);
191                 iter_addresses(pri->dev, open_addr, pri->dev_name);
192         }
193
194         return pri->fd;
195 }
196
197 static void tuntap_close(int fd, void *data)
198 {
199         struct tuntap_data *pri = data;
200
201         if (!pri->fixed_config)
202                 iter_addresses(pri->dev, close_addr, pri->dev_name);
203         close(fd);
204         pri->fd = -1;
205 }
206
207 const struct net_user_info tuntap_user_info = {
208         .init           = tuntap_user_init,
209         .open           = tuntap_open,
210         .close          = tuntap_close,
211         .remove         = NULL,
212         .add_address    = tuntap_add_addr,
213         .delete_address = tuntap_del_addr,
214         .mtu            = ETH_MAX_PACKET,
215         .max_packet     = ETH_MAX_PACKET + ETH_HEADER_OTHER,
216 };