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pcg |
1.1 |
/* |
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vpn.C -- handle the protocol, encryption, handshaking etc. |
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This program is free software; you can redistribute it and/or modify |
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it under the terms of the GNU General Public License as published by |
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the Free Software Foundation; either version 2 of the License, or |
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(at your option) any later version. |
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This program is distributed in the hope that it will be useful, |
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but WITHOUT ANY WARRANTY; without even the implied warranty of |
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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GNU General Public License for more details. |
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You should have received a copy of the GNU General Public License |
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along with this program; if not, write to the Free Software |
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Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
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*/ |
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#include "config.h" |
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#include <list> |
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#include <cstdlib> |
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#include <cstring> |
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#include <cstdio> |
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#include <sys/types.h> |
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#include <sys/socket.h> |
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#include <sys/poll.h> |
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#include <sys/wait.h> |
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#include <netinet/in.h> |
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#include <arpa/inet.h> |
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#include <errno.h> |
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#include <time.h> |
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#include <unistd.h> |
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#include "pidfile.h" |
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#include "connection.h" |
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#include "util.h" |
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#include "vpn.h" |
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///////////////////////////////////////////////////////////////////////////// |
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const char *vpn::script_if_up (int) |
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{ |
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// the tunnel device mtu should be the physical mtu - overhead |
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// the tricky part is rounding to the cipher key blocksize |
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int mtu = conf.mtu - ETH_OVERHEAD - VPE_OVERHEAD - MAX_OVERHEAD; |
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mtu += ETH_OVERHEAD - 6 - 6; // now we have the data portion |
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mtu -= mtu % EVP_CIPHER_block_size (CIPHER); // round |
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mtu -= ETH_OVERHEAD - 6 - 6; // and get interface mtu again |
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char *env; |
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asprintf (&env, "CONFBASE=%s", confbase); |
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putenv (env); |
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asprintf (&env, "NODENAME=%s", THISNODE->nodename); |
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putenv (env); |
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asprintf (&env, "NODEID=%d", THISNODE->id); |
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putenv (env); |
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asprintf (&env, "IFNAME=%s", tap->interface ()); |
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putenv (env); |
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asprintf (&env, "MTU=%d", mtu); |
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putenv (env); |
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asprintf (&env, "MAC=%02x:%02x:%02x:%02x:%02x:%02x", |
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0xfe, 0xfd, 0x80, 0x00, THISNODE->id >> 8, |
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THISNODE->id & 0xff); |
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putenv (env); |
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return ::conf.script_if_up ? ::conf.script_if_up : "if-up"; |
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} |
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int |
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vpn::setup () |
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{ |
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sockinfo si; |
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si.set (THISNODE); |
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udpv4_fd = -1; |
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if (THISNODE->protocols & PROT_UDPv4) |
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{ |
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udpv4_fd = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP); |
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if (udpv4_fd < 0) |
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return -1; |
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if (bind (udpv4_fd, si.sav4 (), si.salenv4 ())) |
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{ |
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slog (L_ERR, _("can't bind udpv4 to %s: %s"), (const char *)si, strerror (errno)); |
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exit (1); |
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} |
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#ifdef IP_MTU_DISCOVER |
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// this I really consider a linux bug. I am neither connected |
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// nor do I fragment myself. Linux still sets DF and doesn't |
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// fragment for me sometimes. |
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{ |
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int oval = IP_PMTUDISC_DONT; |
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setsockopt (udpv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval); |
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} |
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#endif |
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// standard daemon practise... |
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{ |
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int oval = 1; |
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setsockopt (udpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval); |
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} |
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udpv4_ev_watcher.start (udpv4_fd, POLLIN); |
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} |
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ipv4_fd = -1; |
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if (THISNODE->protocols & PROT_IPv4) |
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{ |
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ipv4_fd = socket (PF_INET, SOCK_RAW, ::conf.ip_proto); |
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if (ipv4_fd < 0) |
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return -1; |
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if (bind (ipv4_fd, si.sav4 (), si.salenv4 ())) |
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{ |
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slog (L_ERR, _("can't bind ipv4 socket to %s: %s"), (const char *)si, strerror (errno)); |
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exit (1); |
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} |
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#ifdef IP_MTU_DISCOVER |
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// this I really consider a linux bug. I am neither connected |
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// nor do I fragment myself. Linux still sets DF and doesn't |
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// fragment for me sometimes. |
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{ |
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int oval = IP_PMTUDISC_DONT; |
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setsockopt (ipv4_fd, SOL_IP, IP_MTU_DISCOVER, &oval, sizeof oval); |
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} |
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#endif |
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ipv4_ev_watcher.start (ipv4_fd, POLLIN); |
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} |
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tap = new tap_device (); |
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if (!tap) //D this, of course, never catches |
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{ |
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slog (L_ERR, _("cannot create network interface '%s'"), conf.ifname); |
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exit (1); |
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} |
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run_script (run_script_cb (this, &vpn::script_if_up), true); |
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tap_ev_watcher.start (tap->fd, POLLIN); |
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reconnect_all (); |
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return 0; |
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} |
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void |
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vpn::send_ipv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
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{ |
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setsockopt (ipv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos); |
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sendto (ipv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ()); |
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} |
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void |
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vpn::send_udpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
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{ |
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setsockopt (udpv4_fd, SOL_IP, IP_TOS, &tos, sizeof tos); |
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sendto (udpv4_fd, &((*pkt)[0]), pkt->len, 0, si.sav4 (), si.salenv4 ()); |
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} |
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void |
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vpn::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi) |
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{ |
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unsigned int src = pkt->src (); |
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unsigned int dst = pkt->dst (); |
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slog (L_NOISE, _("<<?/%s received possible vpn packet type %d from %d to %d, length %d"), |
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(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst (), pkt->len); |
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if (src == 0 || src > conns.size () |
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|| dst > conns.size () |
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|| pkt->typ () >= vpn_packet::PT_MAX) |
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slog (L_WARN, _("(%s): received corrupted packet type %d (src %d, dst %d)"), |
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(const char *)rsi, pkt->typ (), pkt->src (), pkt->dst ()); |
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else |
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{ |
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connection *c = conns[src - 1]; |
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if (dst == 0 && !THISNODE->routerprio) |
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slog (L_WARN, _("%s(%s): received broadcast, but we are no router"), |
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c->conf->nodename, (const char *)rsi); |
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else if (dst != 0 && dst != THISNODE->id) |
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// FORWARDING NEEDED ;) |
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slog (L_WARN, |
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_("received frame for node %d ('%s') from %s, but this is node %d ('%s')"), |
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dst, conns[dst - 1]->conf->nodename, |
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(const char *)rsi, |
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THISNODE->id, THISNODE->nodename); |
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else |
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c->recv_vpn_packet (pkt, rsi); |
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} |
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} |
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void |
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vpn::udpv4_ev (short revents) |
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{ |
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if (revents & (POLLIN | POLLERR)) |
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{ |
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vpn_packet *pkt = new vpn_packet; |
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struct sockaddr_in sa; |
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socklen_t sa_len = sizeof (sa); |
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int len; |
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len = recvfrom (udpv4_fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); |
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sockinfo si(sa); |
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if (len > 0) |
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{ |
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pkt->len = len; |
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recv_vpn_packet (pkt, si); |
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} |
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else |
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{ |
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// probably ECONNRESET or somesuch |
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slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno)); |
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} |
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delete pkt; |
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} |
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else if (revents & POLLHUP) |
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{ |
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// this cannot ;) happen on udp sockets |
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slog (L_ERR, _("FATAL: POLLHUP on udp v4 fd, terminating.")); |
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exit (1); |
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} |
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else |
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{ |
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slog (L_ERR, |
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_("FATAL: unknown revents %08x in socket, terminating\n"), |
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revents); |
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exit (1); |
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} |
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} |
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void |
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vpn::ipv4_ev (short revents) |
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{ |
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if (revents & (POLLIN | POLLERR)) |
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{ |
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vpn_packet *pkt = new vpn_packet; |
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struct sockaddr_in sa; |
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socklen_t sa_len = sizeof (sa); |
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int len; |
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len = recvfrom (ipv4_fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); |
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sockinfo si(sa, PROT_IPv4); |
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if (len > 0) |
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{ |
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pkt->len = len; |
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// raw sockets deliver the ipv4, but don't expect it on sends |
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// this is slow, but... |
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pkt->skip_hdr (IP_OVERHEAD); |
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recv_vpn_packet (pkt, si); |
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} |
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else |
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{ |
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// probably ECONNRESET or somesuch |
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slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno)); |
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} |
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delete pkt; |
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} |
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else if (revents & POLLHUP) |
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{ |
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// this cannot ;) happen on udp sockets |
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slog (L_ERR, _("FATAL: POLLHUP on ipv4 fd, terminating.")); |
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exit (1); |
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} |
285 |
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else |
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{ |
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slog (L_ERR, |
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_("FATAL: unknown revents %08x in socket, terminating\n"), |
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revents); |
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exit (1); |
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} |
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} |
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void |
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vpn::tap_ev (short revents) |
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{ |
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if (revents & POLLIN) |
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{ |
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/* process data */ |
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tap_packet *pkt; |
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pkt = tap->recv (); |
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int dst = mac2id (pkt->dst); |
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int src = mac2id (pkt->src); |
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if (src != THISNODE->id) |
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{ |
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slog (L_ERR, _("FATAL: tap packet not originating on current node received, terminating.")); |
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exit (1); |
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} |
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if (dst == THISNODE->id) |
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{ |
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slog (L_ERR, _("FATAL: tap packet destined for current node received, terminating.")); |
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exit (1); |
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} |
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if (dst > conns.size ()) |
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slog (L_ERR, _("tap packet for unknown node %d received, ignoring."), dst); |
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else |
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{ |
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if (dst) |
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{ |
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// unicast |
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if (dst != THISNODE->id) |
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conns[dst - 1]->inject_data_packet (pkt); |
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} |
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else |
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{ |
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// broadcast, first check router, then self, then english |
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connection *router = find_router (); |
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if (router) |
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router->inject_data_packet (pkt, true); |
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else |
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for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
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if ((*c)->conf != THISNODE) |
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(*c)->inject_data_packet (pkt); |
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} |
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} |
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343 |
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delete pkt; |
344 |
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} |
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else if (revents & (POLLHUP | POLLERR)) |
346 |
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{ |
347 |
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slog (L_ERR, _("FATAL: POLLHUP or POLLERR on network device fd, terminating.")); |
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exit (1); |
349 |
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} |
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else |
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abort (); |
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} |
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void |
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vpn::event_cb (tstamp &ts) |
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{ |
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if (events) |
358 |
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{ |
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if (events & EVENT_SHUTDOWN) |
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{ |
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slog (L_INFO, _("preparing shutdown...")); |
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363 |
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shutdown_all (); |
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remove_pid (pidfilename); |
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367 |
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slog (L_INFO, _("terminating")); |
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exit (0); |
370 |
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} |
371 |
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if (events & EVENT_RECONNECT) |
373 |
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{ |
374 |
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slog (L_INFO, _("forced reconnect")); |
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376 |
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reconnect_all (); |
377 |
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} |
378 |
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379 |
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events = 0; |
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} |
381 |
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382 |
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ts = TSTAMP_CANCEL; |
383 |
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} |
384 |
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|
385 |
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void |
386 |
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vpn::shutdown_all () |
387 |
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{ |
388 |
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for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
389 |
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(*c)->shutdown (); |
390 |
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} |
391 |
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392 |
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void |
393 |
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vpn::reconnect_all () |
394 |
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{ |
395 |
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for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
396 |
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delete *c; |
397 |
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398 |
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conns.clear (); |
399 |
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|
400 |
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connection_init (); |
401 |
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|
402 |
|
|
for (configuration::node_vector::iterator i = conf.nodes.begin (); |
403 |
|
|
i != conf.nodes.end (); ++i) |
404 |
|
|
{ |
405 |
|
|
connection *conn = new connection (this); |
406 |
|
|
|
407 |
|
|
conn->conf = *i; |
408 |
|
|
conns.push_back (conn); |
409 |
|
|
|
410 |
|
|
conn->establish_connection (); |
411 |
|
|
} |
412 |
|
|
} |
413 |
|
|
|
414 |
|
|
connection *vpn::find_router () |
415 |
|
|
{ |
416 |
|
|
u32 prio = 0; |
417 |
|
|
connection *router = 0; |
418 |
|
|
|
419 |
|
|
for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i) |
420 |
|
|
{ |
421 |
|
|
connection *c = *i; |
422 |
|
|
|
423 |
|
|
if (c->conf->routerprio > prio |
424 |
|
|
&& c->connectmode == conf_node::C_ALWAYS |
425 |
|
|
&& c->conf != THISNODE |
426 |
|
|
&& c->ictx && c->octx) |
427 |
|
|
{ |
428 |
|
|
prio = c->conf->routerprio; |
429 |
|
|
router = c; |
430 |
|
|
} |
431 |
|
|
} |
432 |
|
|
|
433 |
|
|
return router; |
434 |
|
|
} |
435 |
|
|
|
436 |
|
|
void vpn::connect_request (int id) |
437 |
|
|
{ |
438 |
|
|
connection *c = find_router (); |
439 |
|
|
|
440 |
|
|
if (c) |
441 |
|
|
c->connect_request (id); |
442 |
|
|
//else // does not work, because all others must connect to the same router |
443 |
|
|
// // no router found, aggressively connect to all routers |
444 |
|
|
// for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i) |
445 |
|
|
// if ((*i)->conf->routerprio) |
446 |
|
|
// (*i)->establish_connection (); |
447 |
|
|
} |
448 |
|
|
|
449 |
|
|
void |
450 |
|
|
connection::dump_status () |
451 |
|
|
{ |
452 |
|
|
slog (L_NOTICE, _("node %s (id %d)"), conf->nodename, conf->id); |
453 |
|
|
slog (L_NOTICE, _(" connectmode %d (%d) / sockaddr %s / minor %d"), |
454 |
|
|
connectmode, conf->connectmode, (const char *)si, (int)prot_minor); |
455 |
|
|
slog (L_NOTICE, _(" ictx/octx %08lx/%08lx / oseqno %d / retry_cnt %d"), |
456 |
|
|
(long)ictx, (long)octx, (int)oseqno, (int)retry_cnt); |
457 |
|
|
slog (L_NOTICE, _(" establish_conn %ld / rekey %ld / keepalive %ld"), |
458 |
|
|
(long)(establish_connection.at), (long)(rekey.at), (long)(keepalive.at)); |
459 |
|
|
} |
460 |
|
|
|
461 |
|
|
void |
462 |
|
|
vpn::dump_status () |
463 |
|
|
{ |
464 |
|
|
slog (L_NOTICE, _("BEGIN status dump (%ld)"), (long)NOW); |
465 |
|
|
|
466 |
|
|
for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
467 |
|
|
(*c)->dump_status (); |
468 |
|
|
|
469 |
|
|
slog (L_NOTICE, _("END status dump")); |
470 |
|
|
} |
471 |
|
|
|
472 |
|
|
vpn::vpn (void) |
473 |
|
|
: udpv4_ev_watcher(this, &vpn::udpv4_ev) |
474 |
|
|
, ipv4_ev_watcher(this, &vpn::ipv4_ev) |
475 |
|
|
, tap_ev_watcher(this, &vpn::tap_ev) |
476 |
|
|
, event(this, &vpn::event_cb) |
477 |
|
|
{ |
478 |
|
|
} |
479 |
|
|
|
480 |
|
|
vpn::~vpn () |
481 |
|
|
{ |
482 |
|
|
} |
483 |
|
|
|