You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
89 lines
2.1 KiB
89 lines
2.1 KiB
/* |
|
* Copyright 2014 The Android Open Source Project |
|
* |
|
* Licensed under the Apache License, Version 2.0 (the "License"); |
|
* you may not use this file except in compliance with the License. |
|
* You may obtain a copy of the License at |
|
* |
|
* http://www.apache.org/licenses/LICENSE-2.0 |
|
* |
|
* Unless required by applicable law or agreed to in writing, software |
|
* distributed under the License is distributed on an "AS IS" BASIS, |
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
|
* See the License for the specific language governing permissions and |
|
* limitations under the License. |
|
* |
|
* tun.c - tun device functions |
|
*/ |
|
#include <fcntl.h> |
|
#include <string.h> |
|
#include <unistd.h> |
|
#include <arpa/inet.h> |
|
#include <linux/if.h> |
|
#include <linux/if_tun.h> |
|
#include <sys/ioctl.h> |
|
#include <sys/uio.h> |
|
|
|
#include "clatd.h" |
|
|
|
/* function: tun_open |
|
* tries to open the tunnel device |
|
*/ |
|
int tun_open() { |
|
int fd; |
|
|
|
fd = open("/dev/tun", O_RDWR); |
|
if(fd < 0) { |
|
fd = open("/dev/net/tun", O_RDWR); |
|
} |
|
|
|
return fd; |
|
} |
|
|
|
/* function: tun_alloc |
|
* creates a tun interface and names it |
|
* dev - the name for the new tun device |
|
*/ |
|
int tun_alloc(char *dev, int fd) { |
|
struct ifreq ifr; |
|
int err; |
|
|
|
memset(&ifr, 0, sizeof(ifr)); |
|
|
|
ifr.ifr_flags = IFF_TUN; |
|
if( *dev ) { |
|
strncpy(ifr.ifr_name, dev, IFNAMSIZ); |
|
ifr.ifr_name[IFNAMSIZ-1] = '\0'; |
|
} |
|
|
|
if( (err = ioctl(fd, TUNSETIFF, (void *) &ifr)) < 0 ){ |
|
close(fd); |
|
return err; |
|
} |
|
strcpy(dev, ifr.ifr_name); |
|
return 0; |
|
} |
|
|
|
/* function: set_nonblocking |
|
* sets a filedescriptor to non-blocking mode |
|
* fd - the filedescriptor |
|
* returns: 0 on success, -1 on failure |
|
*/ |
|
int set_nonblocking(int fd) { |
|
int flags = fcntl(fd, F_GETFL); |
|
if (flags == -1) { |
|
return flags; |
|
} |
|
return fcntl(fd, F_SETFL, flags | O_NONBLOCK); |
|
} |
|
|
|
/* function: send_tun |
|
* sends a clat_packet to a tun interface |
|
* fd - the tun filedescriptor |
|
* out - the packet to send |
|
* iov_len - the number of entries in the clat_packet |
|
* returns: number of bytes read on success, -1 on failure |
|
*/ |
|
int send_tun(int fd, clat_packet out, int iov_len) { |
|
return writev(fd, out, iov_len); |
|
}
|
|
|