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/* |
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vpn.C -- handle the protocol, encryption, handshaking etc. |
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|
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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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|
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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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|
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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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|
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#include "config.h" |
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|
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#include <list> |
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|
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#include <cstdlib> |
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#include <cstring> |
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#include <cstdio> |
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|
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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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|
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#include "pidfile.h" |
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|
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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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///////////////////////////////////////////////////////////////////////////// |
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|
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const char *vpn::script_if_up () |
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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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|
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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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|
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return ::conf.script_if_up ? ::conf.script_if_up : "if-up"; |
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} |
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|
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int |
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vpn::setup () |
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{ |
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udpv4_fd = -1; |
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|
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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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|
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if (udpv4_fd < 0) |
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return -1; |
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|
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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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|
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sockinfo si (THISNODE, PROT_UDPv4); |
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|
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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 on %s: %s"), (const char *)si, strerror (errno)); |
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exit (1); |
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} |
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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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|
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udpv4_ev_watcher.start (udpv4_fd, POLLIN); |
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} |
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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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|
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if (ipv4_fd < 0) |
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return -1; |
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|
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sockinfo si (THISNODE, PROT_IPv4); |
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|
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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 on %s: %s"), (const char *)si, strerror (errno)); |
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exit (1); |
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} |
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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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|
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ipv4_ev_watcher.start (ipv4_fd, POLLIN); |
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} |
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|
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#if ENABLE_TCP |
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if (THISNODE->protocols & PROT_TCPv4) |
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{ |
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tcpv4_fd = socket (PF_INET, SOCK_STREAM, IPPROTO_TCP); |
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|
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if (tcpv4_fd < 0) |
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return -1; |
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|
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// standard daemon practise... |
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{ |
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int oval = 1; |
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setsockopt (tcpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval); |
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} |
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|
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sockinfo si (THISNODE, PROT_TCPv4); |
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|
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if (bind (tcpv4_fd, si.sav4 (), si.salenv4 ())) |
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{ |
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slog (L_ERR, _("can't bind tcpv4 on %s: %s"), (const char *)si, strerror (errno)); |
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exit (1); |
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} |
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|
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if (listen (tcpv4_fd, 5)) |
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{ |
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slog (L_ERR, _("can't listen tcpv4 on %s: %s"), (const char *)si, strerror (errno)); |
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exit (1); |
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} |
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|
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tcpv4_ev_watcher.start (tcpv4_fd, POLLIN); |
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} |
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#endif |
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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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|
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run_script (run_script_cb (this, &vpn::script_if_up), true); |
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|
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tap_ev_watcher.start (tap->fd, POLLIN); |
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|
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reconnect_all (); |
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|
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return 0; |
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} |
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|
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// send a vpn packet out to other hosts |
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bool |
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vpn::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
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{ |
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switch (si.prot) |
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{ |
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case PROT_IPv4: |
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return send_ipv4_packet (pkt, si, tos); |
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|
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case PROT_UDPv4: |
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return send_udpv4_packet (pkt, si, tos); |
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|
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#if ENABLE_TCP |
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case PROT_TCPv4: |
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return send_tcpv4_packet (pkt, si, tos); |
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#endif |
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|
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default: |
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slog (L_CRIT, _("%s: FATAL: trying to send packet with unsupported protocol"), (const char *)si); |
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return false; |
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} |
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} |
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|
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bool |
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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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return true; |
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} |
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|
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bool |
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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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return true; |
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} |
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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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|
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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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|
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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 if (dst > conns.size ()) |
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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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|
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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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{ |
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if (THISNODE->routerprio) |
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// the tos setting gets lost here. who cares. |
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conns[dst - 1]->inject_vpn_packet (pkt); |
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else |
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slog (L_WARN, |
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_("%s(%s): forwarding request (=> %s), but we are no router"), |
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c->conf->nodename, (const char *)rsi, |
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conns[dst - 1]->conf->nodename); |
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} |
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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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|
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void |
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vpn::udpv4_ev (io_watcher &w, 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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|
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len = recvfrom (w.fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); |
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|
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sockinfo si(sa, PROT_UDPv4); |
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|
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if (len > 0) |
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{ |
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pkt->len = len; |
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|
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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: fd %d, %s"), (const char *)si, w.fd, strerror (errno)); |
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} |
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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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|
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void |
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vpn::ipv4_ev (io_watcher &w, 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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|
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len = recvfrom (w.fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); |
324 |
|
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sockinfo si(sa, PROT_IPv4); |
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|
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if (len > 0) |
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{ |
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pkt->len = len; |
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|
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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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|
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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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|
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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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} |
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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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|
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void |
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vpn::tap_ev (io_watcher &w, 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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|
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pkt = tap->recv (); |
369 |
|
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int dst = mac2id (pkt->dst); |
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int src = mac2id (pkt->src); |
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|
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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); |
377 |
} |
378 |
|
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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); |
383 |
} |
384 |
|
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if (dst > conns.size ()) |
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slog (L_ERR, _("tap packet for unknown node %d received, ignoring."), dst); |
387 |
else |
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{ |
389 |
if (dst) |
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{ |
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// unicast |
392 |
if (dst != THISNODE->id) |
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conns[dst - 1]->inject_data_packet (pkt); |
394 |
} |
395 |
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 (); |
399 |
|
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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) |
404 |
if ((*c)->conf != THISNODE) |
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(*c)->inject_data_packet (pkt); |
406 |
} |
407 |
} |
408 |
|
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delete pkt; |
410 |
} |
411 |
else if (revents & (POLLHUP | POLLERR)) |
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{ |
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slog (L_ERR, _("FATAL: POLLHUP or POLLERR on network device fd, terminating.")); |
414 |
exit (1); |
415 |
} |
416 |
else |
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abort (); |
418 |
} |
419 |
|
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void |
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vpn::event_cb (time_watcher &w) |
422 |
{ |
423 |
if (events) |
424 |
{ |
425 |
if (events & EVENT_SHUTDOWN) |
426 |
{ |
427 |
slog (L_INFO, _("preparing shutdown...")); |
428 |
|
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shutdown_all (); |
430 |
|
431 |
remove_pid (pidfilename); |
432 |
|
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slog (L_INFO, _("terminating")); |
434 |
|
435 |
exit (0); |
436 |
} |
437 |
|
438 |
if (events & EVENT_RECONNECT) |
439 |
{ |
440 |
slog (L_INFO, _("forced reconnect")); |
441 |
|
442 |
reconnect_all (); |
443 |
} |
444 |
|
445 |
events = 0; |
446 |
} |
447 |
|
448 |
w.at = TSTAMP_CANCEL; |
449 |
} |
450 |
|
451 |
void |
452 |
vpn::shutdown_all () |
453 |
{ |
454 |
for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
455 |
(*c)->shutdown (); |
456 |
} |
457 |
|
458 |
void |
459 |
vpn::reconnect_all () |
460 |
{ |
461 |
for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
462 |
delete *c; |
463 |
|
464 |
conns.clear (); |
465 |
|
466 |
connection_init (); |
467 |
|
468 |
for (configuration::node_vector::iterator i = conf.nodes.begin (); |
469 |
i != conf.nodes.end (); ++i) |
470 |
{ |
471 |
connection *conn = new connection (this); |
472 |
|
473 |
conn->conf = *i; |
474 |
conns.push_back (conn); |
475 |
|
476 |
conn->establish_connection (); |
477 |
} |
478 |
} |
479 |
|
480 |
connection *vpn::find_router () |
481 |
{ |
482 |
u32 prio = 0; |
483 |
connection *router = 0; |
484 |
|
485 |
for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i) |
486 |
{ |
487 |
connection *c = *i; |
488 |
|
489 |
if (c->conf->routerprio > prio |
490 |
&& c->connectmode == conf_node::C_ALWAYS |
491 |
&& c->conf != THISNODE |
492 |
&& c->ictx && c->octx) |
493 |
{ |
494 |
prio = c->conf->routerprio; |
495 |
router = c; |
496 |
} |
497 |
} |
498 |
|
499 |
return router; |
500 |
} |
501 |
|
502 |
void vpn::send_connect_request (int id) |
503 |
{ |
504 |
connection *c = find_router (); |
505 |
|
506 |
if (c) |
507 |
c->send_connect_request (id); |
508 |
else |
509 |
// no router found, aggressively connect to all routers |
510 |
for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i) |
511 |
if ((*i)->conf->routerprio) |
512 |
(*i)->establish_connection (); |
513 |
} |
514 |
|
515 |
void |
516 |
connection::dump_status () |
517 |
{ |
518 |
slog (L_NOTICE, _("node %s (id %d)"), conf->nodename, conf->id); |
519 |
slog (L_NOTICE, _(" connectmode %d (%d) / sockaddr %s / minor %d"), |
520 |
connectmode, conf->connectmode, (const char *)si, (int)prot_minor); |
521 |
slog (L_NOTICE, _(" ictx/octx %08lx/%08lx / oseqno %d / retry_cnt %d"), |
522 |
(long)ictx, (long)octx, (int)oseqno, (int)retry_cnt); |
523 |
slog (L_NOTICE, _(" establish_conn %ld / rekey %ld / keepalive %ld"), |
524 |
(long)(establish_connection.at), (long)(rekey.at), (long)(keepalive.at)); |
525 |
} |
526 |
|
527 |
void |
528 |
vpn::dump_status () |
529 |
{ |
530 |
slog (L_NOTICE, _("BEGIN status dump (%ld)"), (long)NOW); |
531 |
|
532 |
for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
533 |
(*c)->dump_status (); |
534 |
|
535 |
slog (L_NOTICE, _("END status dump")); |
536 |
} |
537 |
|
538 |
vpn::vpn (void) |
539 |
: event(this, &vpn::event_cb) |
540 |
, udpv4_ev_watcher(this, &vpn::udpv4_ev) |
541 |
, ipv4_ev_watcher (this, &vpn::ipv4_ev) |
542 |
, tap_ev_watcher (this, &vpn::tap_ev) |
543 |
#if ENABLE_TCP |
544 |
, tcpv4_ev_watcher(this, &vpn::tcpv4_ev) |
545 |
#endif |
546 |
{ |
547 |
} |
548 |
|
549 |
vpn::~vpn () |
550 |
{ |
551 |
} |
552 |
|