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0006 #include <stdio.h>
0007 #include <unistd.h>
0008 #include <errno.h>
0009 #include <string.h>
0010 #include <linux/if_tun.h>
0011 #include <net/if.h>
0012 #include <sys/ioctl.h>
0013 #include <sys/socket.h>
0014 #include <sys/wait.h>
0015 #include <sys/uio.h>
0016 #include <kern_util.h>
0017 #include <os.h>
0018 #include "tuntap.h"
0019
0020 static int tuntap_user_init(void *data, void *dev)
0021 {
0022 struct tuntap_data *pri = data;
0023
0024 pri->dev = dev;
0025 return 0;
0026 }
0027
0028 static void tuntap_add_addr(unsigned char *addr, unsigned char *netmask,
0029 void *data)
0030 {
0031 struct tuntap_data *pri = data;
0032
0033 tap_check_ips(pri->gate_addr, addr);
0034 if ((pri->fd == -1) || pri->fixed_config)
0035 return;
0036 open_addr(addr, netmask, pri->dev_name);
0037 }
0038
0039 static void tuntap_del_addr(unsigned char *addr, unsigned char *netmask,
0040 void *data)
0041 {
0042 struct tuntap_data *pri = data;
0043
0044 if ((pri->fd == -1) || pri->fixed_config)
0045 return;
0046 close_addr(addr, netmask, pri->dev_name);
0047 }
0048
0049 struct tuntap_pre_exec_data {
0050 int stdout_fd;
0051 int close_me;
0052 };
0053
0054 static void tuntap_pre_exec(void *arg)
0055 {
0056 struct tuntap_pre_exec_data *data = arg;
0057
0058 dup2(data->stdout_fd, 1);
0059 close(data->close_me);
0060 }
0061
0062 static int tuntap_open_tramp(char *gate, int *fd_out, int me, int remote,
0063 char *buffer, int buffer_len, int *used_out)
0064 {
0065 struct tuntap_pre_exec_data data;
0066 char version_buf[sizeof("nnnnn\0")];
0067 char *argv[] = { "uml_net", version_buf, "tuntap", "up", gate,
0068 NULL };
0069 char buf[CMSG_SPACE(sizeof(*fd_out))];
0070 struct msghdr msg;
0071 struct cmsghdr *cmsg;
0072 struct iovec iov;
0073 int pid, n, err;
0074
0075 sprintf(version_buf, "%d", UML_NET_VERSION);
0076
0077 data.stdout_fd = remote;
0078 data.close_me = me;
0079
0080 pid = run_helper(tuntap_pre_exec, &data, argv);
0081
0082 if (pid < 0)
0083 return pid;
0084
0085 close(remote);
0086
0087 msg.msg_name = NULL;
0088 msg.msg_namelen = 0;
0089 if (buffer != NULL) {
0090 iov = ((struct iovec) { buffer, buffer_len });
0091 msg.msg_iov = &iov;
0092 msg.msg_iovlen = 1;
0093 }
0094 else {
0095 msg.msg_iov = NULL;
0096 msg.msg_iovlen = 0;
0097 }
0098 msg.msg_control = buf;
0099 msg.msg_controllen = sizeof(buf);
0100 msg.msg_flags = 0;
0101 n = recvmsg(me, &msg, 0);
0102 *used_out = n;
0103 if (n < 0) {
0104 err = -errno;
0105 printk(UM_KERN_ERR "tuntap_open_tramp : recvmsg failed - "
0106 "errno = %d\n", errno);
0107 return err;
0108 }
0109 helper_wait(pid);
0110
0111 cmsg = CMSG_FIRSTHDR(&msg);
0112 if (cmsg == NULL) {
0113 printk(UM_KERN_ERR "tuntap_open_tramp : didn't receive a "
0114 "message\n");
0115 return -EINVAL;
0116 }
0117 if ((cmsg->cmsg_level != SOL_SOCKET) ||
0118 (cmsg->cmsg_type != SCM_RIGHTS)) {
0119 printk(UM_KERN_ERR "tuntap_open_tramp : didn't receive a "
0120 "descriptor\n");
0121 return -EINVAL;
0122 }
0123 *fd_out = ((int *) CMSG_DATA(cmsg))[0];
0124 os_set_exec_close(*fd_out);
0125 return 0;
0126 }
0127
0128 static int tuntap_open(void *data)
0129 {
0130 struct ifreq ifr;
0131 struct tuntap_data *pri = data;
0132 char *output, *buffer;
0133 int err, fds[2], len, used;
0134
0135 err = tap_open_common(pri->dev, pri->gate_addr);
0136 if (err < 0)
0137 return err;
0138
0139 if (pri->fixed_config) {
0140 pri->fd = os_open_file("/dev/net/tun",
0141 of_cloexec(of_rdwr(OPENFLAGS())), 0);
0142 if (pri->fd < 0) {
0143 printk(UM_KERN_ERR "Failed to open /dev/net/tun, "
0144 "err = %d\n", -pri->fd);
0145 return pri->fd;
0146 }
0147 memset(&ifr, 0, sizeof(ifr));
0148 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
0149 strlcpy(ifr.ifr_name, pri->dev_name, sizeof(ifr.ifr_name));
0150 if (ioctl(pri->fd, TUNSETIFF, &ifr) < 0) {
0151 err = -errno;
0152 printk(UM_KERN_ERR "TUNSETIFF failed, errno = %d\n",
0153 errno);
0154 close(pri->fd);
0155 return err;
0156 }
0157 }
0158 else {
0159 err = socketpair(AF_UNIX, SOCK_DGRAM, 0, fds);
0160 if (err) {
0161 err = -errno;
0162 printk(UM_KERN_ERR "tuntap_open : socketpair failed - "
0163 "errno = %d\n", errno);
0164 return err;
0165 }
0166
0167 buffer = get_output_buffer(&len);
0168 if (buffer != NULL)
0169 len--;
0170 used = 0;
0171
0172 err = tuntap_open_tramp(pri->gate_addr, &pri->fd, fds[0],
0173 fds[1], buffer, len, &used);
0174
0175 output = buffer;
0176 if (err < 0) {
0177 printk("%s", output);
0178 free_output_buffer(buffer);
0179 printk(UM_KERN_ERR "tuntap_open_tramp failed - "
0180 "err = %d\n", -err);
0181 return err;
0182 }
0183
0184 pri->dev_name = uml_strdup(buffer);
0185 output += IFNAMSIZ;
0186 printk("%s", output);
0187 free_output_buffer(buffer);
0188
0189 close(fds[0]);
0190 iter_addresses(pri->dev, open_addr, pri->dev_name);
0191 }
0192
0193 return pri->fd;
0194 }
0195
0196 static void tuntap_close(int fd, void *data)
0197 {
0198 struct tuntap_data *pri = data;
0199
0200 if (!pri->fixed_config)
0201 iter_addresses(pri->dev, close_addr, pri->dev_name);
0202 close(fd);
0203 pri->fd = -1;
0204 }
0205
0206 const struct net_user_info tuntap_user_info = {
0207 .init = tuntap_user_init,
0208 .open = tuntap_open,
0209 .close = tuntap_close,
0210 .remove = NULL,
0211 .add_address = tuntap_add_addr,
0212 .delete_address = tuntap_del_addr,
0213 .mtu = ETH_MAX_PACKET,
0214 .max_packet = ETH_MAX_PACKET + ETH_HEADER_OTHER,
0215 };
