| /* |
| * TUN interface functions. |
| * Copyright (C) 2002, 2003 Mondru AB. |
| * |
| * The contents of this file may be used under the terms of the GNU |
| * General Public License Version 2, provided that the above copyright |
| * notice and this permission notice is included in all copies or |
| * substantial portions of the software. |
| * |
| * The initial developer of the original code is |
| * Jens Jakobsen <jj@openggsn.org> |
| * |
| * Contributor(s): |
| * |
| */ |
| |
| /* |
| * tun.c: Contains all TUN functionality. Is able to handle multiple |
| * tunnels in the same program. Each tunnel is identified by the struct, |
| * which is passed to functions. |
| * |
| */ |
| |
| |
| #include <syslog.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <sys/types.h> |
| #include <sys/socket.h> |
| #include <netinet/in.h> |
| #include <arpa/inet.h> |
| #include <sys/stat.h> |
| #include <sys/time.h> |
| #include <unistd.h> |
| #include <string.h> |
| #include <errno.h> |
| #include <fcntl.h> |
| |
| #include <stdio.h> |
| #include <fcntl.h> |
| #include <unistd.h> |
| #include <sys/time.h> |
| #include <sys/types.h> |
| #include <sys/ioctl.h> |
| #include <sys/socket.h> |
| #include <linux/if.h> |
| #include <errno.h> |
| #include <linux/if_tun.h> |
| #include <net/route.h> |
| |
| #include <linux/netlink.h> |
| #include <linux/rtnetlink.h> |
| |
| #include "tun.h" |
| #include "syserr.h" |
| |
| |
| |
| int tun_nlattr(struct nlmsghdr *n, int nsize, int type, void *d, int dlen) |
| { |
| int len = RTA_LENGTH(dlen); |
| int alen = NLMSG_ALIGN(n->nlmsg_len); |
| struct rtattr *rta = (struct rtattr*) (((void*)n) + alen); |
| if (alen + len > nsize) |
| return -1; |
| rta->rta_len = len; |
| rta->rta_type = type; |
| memcpy(RTA_DATA(rta), d, dlen); |
| n->nlmsg_len = alen + len; |
| return 0; |
| } |
| |
| int tun_gifindex(struct tun_t *this, int *index) { |
| struct ifreq ifr; |
| int fd; |
| |
| memset (&ifr, '\0', sizeof (ifr)); |
| ifr.ifr_addr.sa_family = AF_INET; |
| ifr.ifr_dstaddr.sa_family = AF_INET; |
| ifr.ifr_netmask.sa_family = AF_INET; |
| strncpy(ifr.ifr_name, this->devname, IFNAMSIZ); |
| ifr.ifr_name[IFNAMSIZ-1] = 0; /* Make sure to terminate */ |
| if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "socket() failed"); |
| } |
| if (ioctl(fd, SIOCGIFINDEX, &ifr)) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "ioctl() failed"); |
| close(fd); |
| return -1; |
| } |
| close(fd); |
| *index = ifr.ifr_ifindex; |
| return 0; |
| } |
| |
| int tun_sifflags(struct tun_t *this, int flags) { |
| struct ifreq ifr; |
| int fd; |
| |
| memset (&ifr, '\0', sizeof (ifr)); |
| ifr.ifr_flags = flags; |
| strncpy(ifr.ifr_name, this->devname, IFNAMSIZ); |
| ifr.ifr_name[IFNAMSIZ-1] = 0; /* Make sure to terminate */ |
| if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "socket() failed"); |
| } |
| if (ioctl(fd, SIOCSIFFLAGS, &ifr)) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "ioctl(SIOCSIFFLAGS) failed"); |
| close(fd); |
| return -1; |
| } |
| close(fd); |
| return 0; |
| } |
| |
| |
| /* Currently unused */ |
| int tun_addroute2(struct tun_t *this, |
| struct in_addr *dst, |
| struct in_addr *gateway, |
| struct in_addr *mask) { |
| |
| struct { |
| struct nlmsghdr n; |
| struct rtmsg r; |
| char buf[TUN_NLBUFSIZE]; |
| } req; |
| |
| struct sockaddr_nl local; |
| int addr_len; |
| int fd; |
| int status; |
| struct sockaddr_nl nladdr; |
| struct iovec iov; |
| struct msghdr msg; |
| |
| memset(&req, 0, sizeof(req)); |
| req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg)); |
| req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE; |
| req.n.nlmsg_type = RTM_NEWROUTE; |
| req.r.rtm_family = AF_INET; |
| req.r.rtm_table = RT_TABLE_MAIN; |
| req.r.rtm_protocol = RTPROT_BOOT; |
| req.r.rtm_scope = RT_SCOPE_UNIVERSE; |
| req.r.rtm_type = RTN_UNICAST; |
| tun_nlattr(&req.n, sizeof(req), RTA_DST, dst, 4); |
| tun_nlattr(&req.n, sizeof(req), RTA_GATEWAY, gateway, 4); |
| |
| if ((fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE)) < 0) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "socket() failed"); |
| return -1; |
| } |
| |
| memset(&local, 0, sizeof(local)); |
| local.nl_family = AF_NETLINK; |
| local.nl_groups = 0; |
| |
| if (bind(fd, (struct sockaddr*)&local, sizeof(local)) < 0) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "bind() failed"); |
| close(fd); |
| return -1; |
| } |
| |
| addr_len = sizeof(local); |
| if (getsockname(fd, (struct sockaddr*)&local, &addr_len) < 0) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "getsockname() failed"); |
| close(fd); |
| return -1; |
| } |
| |
| if (addr_len != sizeof(local)) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, 0, |
| "Wrong address length %d", addr_len); |
| close(fd); |
| return -1; |
| } |
| |
| if (local.nl_family != AF_NETLINK) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, 0, |
| "Wrong address family %d", local.nl_family); |
| close(fd); |
| return -1; |
| } |
| |
| iov.iov_base = (void*)&req.n; |
| iov.iov_len = req.n.nlmsg_len; |
| |
| msg.msg_name = (void*)&nladdr; |
| msg.msg_namelen = sizeof(nladdr), |
| msg.msg_iov = &iov; |
| msg.msg_iovlen = 1; |
| msg.msg_control = NULL; |
| msg.msg_controllen = 0; |
| msg.msg_flags = 0; |
| |
| memset(&nladdr, 0, sizeof(nladdr)); |
| nladdr.nl_family = AF_NETLINK; |
| nladdr.nl_pid = 0; |
| nladdr.nl_groups = 0; |
| |
| req.n.nlmsg_seq = 0; |
| req.n.nlmsg_flags |= NLM_F_ACK; |
| |
| status = sendmsg(fd, &msg, 0); /* TODO: Error check */ |
| close(fd); |
| return 0; |
| } |
| |
| |
| int tun_addaddr(struct tun_t *this, |
| struct in_addr *addr, |
| struct in_addr *dstaddr, |
| struct in_addr *netmask) { |
| struct { |
| struct nlmsghdr n; |
| struct ifaddrmsg i; |
| char buf[TUN_NLBUFSIZE]; |
| } req; |
| |
| struct sockaddr_nl local; |
| int addr_len; |
| int fd; |
| int status; |
| |
| struct sockaddr_nl nladdr; |
| struct iovec iov; |
| struct msghdr msg; |
| |
| if (!this->addrs) /* Use ioctl for first addr to make ping work */ |
| return tun_setaddr(this, addr, dstaddr, netmask); |
| |
| memset(&req, 0, sizeof(req)); |
| req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct ifaddrmsg)); |
| req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE; |
| req.n.nlmsg_type = RTM_NEWADDR; |
| req.i.ifa_family = AF_INET; |
| req.i.ifa_prefixlen = 32; /* 32 FOR IPv4 */ |
| req.i.ifa_flags = 0; |
| req.i.ifa_scope = RT_SCOPE_HOST; /* TODO or 0 */ |
| if (tun_gifindex(this, &req.i.ifa_index)) { |
| return -1; |
| } |
| |
| tun_nlattr(&req.n, sizeof(req), IFA_ADDRESS, addr, sizeof(addr)); |
| tun_nlattr(&req.n, sizeof(req), IFA_LOCAL, dstaddr, sizeof(dstaddr)); |
| |
| if ((fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE)) < 0) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "socket() failed"); |
| return -1; |
| } |
| |
| memset(&local, 0, sizeof(local)); |
| local.nl_family = AF_NETLINK; |
| local.nl_groups = 0; |
| |
| if (bind(fd, (struct sockaddr*)&local, sizeof(local)) < 0) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "bind() failed"); |
| close(fd); |
| return -1; |
| } |
| |
| addr_len = sizeof(local); |
| if (getsockname(fd, (struct sockaddr*)&local, &addr_len) < 0) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "getsockname() failed"); |
| close(fd); |
| return -1; |
| } |
| |
| if (addr_len != sizeof(local)) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, 0, |
| "Wrong address length %d", addr_len); |
| close(fd); |
| return -1; |
| } |
| |
| if (local.nl_family != AF_NETLINK) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, 0, |
| "Wrong address family %d", local.nl_family); |
| close(fd); |
| return -1; |
| } |
| |
| iov.iov_base = (void*)&req.n; |
| iov.iov_len = req.n.nlmsg_len; |
| |
| msg.msg_name = (void*)&nladdr; |
| msg.msg_namelen = sizeof(nladdr), |
| msg.msg_iov = &iov; |
| msg.msg_iovlen = 1; |
| msg.msg_control = NULL; |
| msg.msg_controllen = 0; |
| msg.msg_flags = 0; |
| |
| memset(&nladdr, 0, sizeof(nladdr)); |
| nladdr.nl_family = AF_NETLINK; |
| nladdr.nl_pid = 0; |
| nladdr.nl_groups = 0; |
| |
| req.n.nlmsg_seq = 0; |
| req.n.nlmsg_flags |= NLM_F_ACK; |
| |
| status = sendmsg(fd, &msg, 0); /* TODO Error check */ |
| |
| tun_sifflags(this, IFF_UP | IFF_RUNNING); |
| close(fd); |
| this->addrs++; |
| return 0; |
| } |
| |
| |
| int tun_setaddr(struct tun_t *this, |
| struct in_addr *addr, |
| struct in_addr *dstaddr, |
| struct in_addr *netmask) |
| { |
| struct ifreq ifr; |
| int fd; |
| |
| memset (&ifr, '\0', sizeof (ifr)); |
| ifr.ifr_addr.sa_family = AF_INET; |
| ifr.ifr_dstaddr.sa_family = AF_INET; |
| ifr.ifr_netmask.sa_family = AF_INET; |
| strncpy(ifr.ifr_name, this->devname, IFNAMSIZ); |
| ifr.ifr_name[IFNAMSIZ-1] = 0; /* Make sure to terminate */ |
| |
| /* Create a channel to the NET kernel. */ |
| if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "socket() failed"); |
| return -1; |
| } |
| |
| if (addr) { /* Set the interface address */ |
| this->addr.s_addr = addr->s_addr; |
| ((struct sockaddr_in *) &ifr.ifr_addr)->sin_addr.s_addr = addr->s_addr; |
| if (ioctl(fd, SIOCSIFADDR, (void *) &ifr) < 0) { |
| if (errno != EEXIST) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "ioctl(SIOCSIFADDR) failed"); |
| } |
| else { |
| sys_err(LOG_WARNING, __FILE__, __LINE__, errno, |
| "ioctl(SIOCSIFADDR): Address already exists"); |
| } |
| close(fd); |
| return -1; |
| } |
| } |
| |
| if (dstaddr) { /* Set the destination address */ |
| this->dstaddr.s_addr = dstaddr->s_addr; |
| ((struct sockaddr_in *) &ifr.ifr_dstaddr)->sin_addr.s_addr = |
| dstaddr->s_addr; |
| if (ioctl(fd, SIOCSIFDSTADDR, (caddr_t) &ifr) < 0) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "ioctl(SIOCSIFDSTADDR) failed"); |
| close(fd); |
| return -1; |
| } |
| } |
| |
| if (netmask) { /* Set the netmask */ |
| this->netmask.s_addr = netmask->s_addr; |
| ((struct sockaddr_in *) &ifr.ifr_netmask)->sin_addr.s_addr = |
| netmask->s_addr; |
| if (ioctl(fd, SIOCSIFNETMASK, (void *) &ifr) < 0) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "ioctl(SIOCSIFNETMASK) failed"); |
| close(fd); |
| return -1; |
| } |
| } |
| |
| close(fd); |
| this->addrs++; |
| return tun_sifflags(this, IFF_UP | IFF_RUNNING); |
| } |
| |
| int tun_addroute(struct tun_t *this, |
| struct in_addr *dst, |
| struct in_addr *gateway, |
| struct in_addr *mask) |
| { |
| struct rtentry r; |
| int fd; |
| |
| memset (&r, '\0', sizeof (r)); |
| r.rt_flags = RTF_UP | RTF_GATEWAY; /* RTF_HOST not set */ |
| |
| /* Create a channel to the NET kernel. */ |
| if ((fd = socket(AF_INET, SOCK_DGRAM, 0)) < 0) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "socket() failed"); |
| return -1; |
| } |
| |
| r.rt_dst.sa_family = AF_INET; |
| r.rt_gateway.sa_family = AF_INET; |
| r.rt_genmask.sa_family = AF_INET; |
| ((struct sockaddr_in *) &r.rt_dst)->sin_addr.s_addr = dst->s_addr; |
| ((struct sockaddr_in *) &r.rt_gateway)->sin_addr.s_addr = gateway->s_addr; |
| ((struct sockaddr_in *) &r.rt_genmask)->sin_addr.s_addr = mask->s_addr; |
| |
| if (ioctl(fd, SIOCADDRT, (void *) &r) < 0) { /* SIOCDELRT */ |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, |
| "ioctl(SIOCADDRT) failed"); |
| close(fd); |
| return -1; |
| } |
| close(fd); |
| return 0; |
| } |
| |
| |
| int tun_new(struct tun_t **tun) |
| { |
| struct ifreq ifr; |
| |
| if (!(*tun = calloc(1, sizeof(struct tun_t)))) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, "calloc() failed"); |
| return EOF; |
| } |
| |
| (*tun)->cb_ind = NULL; |
| (*tun)->addrs = 0; |
| |
| if (((*tun)->fd = open("/dev/net/tun", O_RDWR)) < 0) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, "open() failed"); |
| return -1; |
| } |
| |
| memset(&ifr, 0, sizeof(ifr)); |
| ifr.ifr_flags = IFF_TUN | IFF_NO_PI; /* Tun device, no packet info */ |
| strncpy(ifr.ifr_name, (*tun)->devname, IFNAMSIZ); |
| |
| if (ioctl((*tun)->fd, TUNSETIFF, (void *) &ifr) < 0) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, "ioctl() failed"); |
| close((*tun)->fd); |
| return -1; |
| } |
| |
| ioctl((*tun)->fd, TUNSETNOCSUM, 1); /* Disable checksums */ |
| |
| strncpy((*tun)->devname, ifr.ifr_name, IFNAMSIZ); |
| (*tun)->devname[IFNAMSIZ] = 0; |
| |
| return 0; |
| } |
| |
| int tun_free(struct tun_t *tun) |
| { |
| if (close(tun->fd)) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, "close() failed"); |
| } |
| |
| free(tun); |
| return 0; |
| } |
| |
| |
| int tun_set_cb_ind(struct tun_t *this, |
| int (*cb_ind) (struct tun_t *tun, void *pack, unsigned len)) { |
| this->cb_ind = cb_ind; |
| return 0; |
| } |
| |
| |
| int tun_decaps(struct tun_t *this) |
| { |
| unsigned char buffer[PACKET_MAX]; |
| int status; |
| |
| if ((status = read(this->fd, buffer, sizeof(buffer))) <= 0) { |
| sys_err(LOG_ERR, __FILE__, __LINE__, errno, "read() failed"); |
| return -1; |
| } |
| |
| if (this->cb_ind) |
| return this->cb_ind(this, buffer, status); |
| |
| return 0; |
| } |
| |
| int tun_encaps(struct tun_t *tun, void *pack, unsigned len) |
| { |
| return write(tun->fd, pack, len); |
| } |
| |
| int tun_runscript(struct tun_t *tun, char* script) { |
| |
| char buf[TUN_SCRIPTSIZE]; |
| char snet[TUN_ADDRSIZE]; |
| char smask[TUN_ADDRSIZE]; |
| |
| strncpy(snet, inet_ntoa(tun->addr), sizeof(snet)); |
| snet[sizeof(snet)-1] = 0; |
| strncpy(smask, inet_ntoa(tun->netmask), sizeof(smask)); |
| smask[sizeof(smask)-1] = 0; |
| |
| /* system("ipup /dev/tun0 192.168.0.10 255.255.255.0"); */ |
| snprintf(buf, sizeof(buf), "%s %s %s %s", |
| script, tun->devname, snet, smask); |
| buf[sizeof(buf)-1] = 0; |
| system(buf); |
| return 0; |
| } |