| 1 |
/* |
| 2 |
vpn.C -- handle the protocol, encryption, handshaking etc. |
| 3 |
|
| 4 |
This program is free software; you can redistribute it and/or modify |
| 5 |
it under the terms of the GNU General Public License as published by |
| 6 |
the Free Software Foundation; either version 2 of the License, or |
| 7 |
(at your option) any later version. |
| 8 |
|
| 9 |
This program is distributed in the hope that it will be useful, |
| 10 |
but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 |
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 |
GNU General Public License for more details. |
| 13 |
|
| 14 |
You should have received a copy of the GNU General Public License |
| 15 |
along with this program; if not, write to the Free Software |
| 16 |
Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 17 |
*/ |
| 18 |
|
| 19 |
#include "config.h" |
| 20 |
|
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#include <list> |
| 22 |
|
| 23 |
#include <cstdlib> |
| 24 |
#include <cstring> |
| 25 |
#include <cstdio> |
| 26 |
|
| 27 |
#include <sys/types.h> |
| 28 |
#include <sys/socket.h> |
| 29 |
#include <sys/poll.h> |
| 30 |
#include <sys/wait.h> |
| 31 |
#include <netinet/in.h> |
| 32 |
#include <arpa/inet.h> |
| 33 |
#include <errno.h> |
| 34 |
#include <time.h> |
| 35 |
#include <unistd.h> |
| 36 |
|
| 37 |
#include "pidfile.h" |
| 38 |
|
| 39 |
#include "connection.h" |
| 40 |
#include "util.h" |
| 41 |
#include "vpn.h" |
| 42 |
|
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///////////////////////////////////////////////////////////////////////////// |
| 44 |
|
| 45 |
const char *vpn::script_if_up () |
| 46 |
{ |
| 47 |
// the tunnel device mtu should be the physical mtu - overhead |
| 48 |
// the tricky part is rounding to the cipher key blocksize |
| 49 |
int mtu = conf.mtu - ETH_OVERHEAD - VPE_OVERHEAD - MAX_OVERHEAD; |
| 50 |
mtu += ETH_OVERHEAD - 6 - 6; // now we have the data portion |
| 51 |
mtu -= mtu % EVP_CIPHER_block_size (CIPHER); // round |
| 52 |
mtu -= ETH_OVERHEAD - 6 - 6; // and get interface mtu again |
| 53 |
|
| 54 |
char *env; |
| 55 |
asprintf (&env, "CONFBASE=%s", confbase); |
| 56 |
putenv (env); |
| 57 |
asprintf (&env, "NODENAME=%s", THISNODE->nodename); |
| 58 |
putenv (env); |
| 59 |
asprintf (&env, "NODEID=%d", THISNODE->id); |
| 60 |
putenv (env); |
| 61 |
asprintf (&env, "IFNAME=%s", tap->interface ()); |
| 62 |
putenv (env); |
| 63 |
asprintf (&env, "MTU=%d", mtu); |
| 64 |
putenv (env); |
| 65 |
asprintf (&env, "MAC=%02x:%02x:%02x:%02x:%02x:%02x", |
| 66 |
0xfe, 0xfd, 0x80, 0x00, THISNODE->id >> 8, |
| 67 |
THISNODE->id & 0xff); |
| 68 |
putenv (env); |
| 69 |
|
| 70 |
return ::conf.script_if_up ? ::conf.script_if_up : "if-up"; |
| 71 |
} |
| 72 |
|
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int |
| 74 |
vpn::setup () |
| 75 |
{ |
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udpv4_fd = -1; |
| 77 |
|
| 78 |
if (THISNODE->protocols & PROT_UDPv4) |
| 79 |
{ |
| 80 |
udpv4_fd = socket (PF_INET, SOCK_DGRAM, IPPROTO_UDP); |
| 81 |
|
| 82 |
if (udpv4_fd < 0) |
| 83 |
return -1; |
| 84 |
|
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// standard daemon practise... |
| 86 |
{ |
| 87 |
int oval = 1; |
| 88 |
setsockopt (udpv4_fd, SOL_SOCKET, SO_REUSEADDR, &oval, sizeof oval); |
| 89 |
} |
| 90 |
|
| 91 |
sockinfo si (THISNODE, PROT_UDPv4); |
| 92 |
|
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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); |
| 97 |
} |
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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 |
| 102 |
// 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); |
| 110 |
} |
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|
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ipv4_fd = -1; |
| 113 |
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); |
| 126 |
} |
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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 |
| 131 |
// 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); |
| 161 |
} |
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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 |
| 175 |
{ |
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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; |
| 187 |
} |
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|
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// send a vpn packet out to other hosts |
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void |
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vpn::send_vpn_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
| 192 |
{ |
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switch (si.prot) |
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{ |
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case PROT_IPv4: |
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send_ipv4_packet (pkt, si, tos); |
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break; |
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|
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case PROT_UDPv4: |
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send_udpv4_packet (pkt, si, tos); |
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break; |
| 202 |
|
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#if ENABLE_TCP |
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case PROT_TCPv4: |
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send_tcpv4_packet (pkt, si, tos); |
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break; |
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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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abort (); |
| 212 |
} |
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} |
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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) |
| 217 |
{ |
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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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} |
| 221 |
|
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void |
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vpn::send_udpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
| 224 |
{ |
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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 ()); |
| 227 |
} |
| 228 |
|
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void |
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vpn::recv_vpn_packet (vpn_packet *pkt, const sockinfo &rsi) |
| 231 |
{ |
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unsigned int src = pkt->src (); |
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unsigned int dst = pkt->dst (); |
| 234 |
|
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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); |
| 237 |
|
| 238 |
if (src == 0 || src > conns.size () |
| 239 |
|| dst > conns.size () |
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|| pkt->typ () >= vpn_packet::PT_MAX) |
| 241 |
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 ()); |
| 243 |
else |
| 244 |
{ |
| 245 |
connection *c = conns[src - 1]; |
| 246 |
|
| 247 |
if (dst == 0 && !THISNODE->routerprio) |
| 248 |
slog (L_WARN, _("%s(%s): received broadcast, but we are no router"), |
| 249 |
c->conf->nodename, (const char *)rsi); |
| 250 |
else if (dst != 0 && dst != THISNODE->id) |
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// FORWARDING NEEDED ;) |
| 252 |
slog (L_WARN, |
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_("received frame for node %d ('%s') from %s, but this is node %d ('%s')"), |
| 254 |
dst, conns[dst - 1]->conf->nodename, |
| 255 |
(const char *)rsi, |
| 256 |
THISNODE->id, THISNODE->nodename); |
| 257 |
else |
| 258 |
c->recv_vpn_packet (pkt, rsi); |
| 259 |
} |
| 260 |
} |
| 261 |
|
| 262 |
void |
| 263 |
vpn::udpv4_ev (io_watcher &w, short revents) |
| 264 |
{ |
| 265 |
if (revents & (POLLIN | POLLERR)) |
| 266 |
{ |
| 267 |
vpn_packet *pkt = new vpn_packet; |
| 268 |
struct sockaddr_in sa; |
| 269 |
socklen_t sa_len = sizeof (sa); |
| 270 |
int len; |
| 271 |
|
| 272 |
len = recvfrom (w.fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); |
| 273 |
|
| 274 |
sockinfo si(sa, PROT_UDPv4); |
| 275 |
|
| 276 |
if (len > 0) |
| 277 |
{ |
| 278 |
pkt->len = len; |
| 279 |
|
| 280 |
recv_vpn_packet (pkt, si); |
| 281 |
} |
| 282 |
else |
| 283 |
{ |
| 284 |
// probably ECONNRESET or somesuch |
| 285 |
slog (L_DEBUG, _("%s: fd %d, %s"), (const char *)si, w.fd, strerror (errno)); |
| 286 |
} |
| 287 |
|
| 288 |
delete pkt; |
| 289 |
} |
| 290 |
else if (revents & POLLHUP) |
| 291 |
{ |
| 292 |
// this cannot ;) happen on udp sockets |
| 293 |
slog (L_ERR, _("FATAL: POLLHUP on udp v4 fd, terminating.")); |
| 294 |
exit (1); |
| 295 |
} |
| 296 |
else |
| 297 |
{ |
| 298 |
slog (L_ERR, |
| 299 |
_("FATAL: unknown revents %08x in socket, terminating\n"), |
| 300 |
revents); |
| 301 |
exit (1); |
| 302 |
} |
| 303 |
} |
| 304 |
|
| 305 |
void |
| 306 |
vpn::ipv4_ev (io_watcher &w, short revents) |
| 307 |
{ |
| 308 |
if (revents & (POLLIN | POLLERR)) |
| 309 |
{ |
| 310 |
vpn_packet *pkt = new vpn_packet; |
| 311 |
struct sockaddr_in sa; |
| 312 |
socklen_t sa_len = sizeof (sa); |
| 313 |
int len; |
| 314 |
|
| 315 |
len = recvfrom (w.fd, &((*pkt)[0]), MAXSIZE, 0, (sockaddr *)&sa, &sa_len); |
| 316 |
|
| 317 |
sockinfo si(sa, PROT_IPv4); |
| 318 |
|
| 319 |
if (len > 0) |
| 320 |
{ |
| 321 |
pkt->len = len; |
| 322 |
|
| 323 |
// raw sockets deliver the ipv4, but don't expect it on sends |
| 324 |
// this is slow, but... |
| 325 |
pkt->skip_hdr (IP_OVERHEAD); |
| 326 |
|
| 327 |
recv_vpn_packet (pkt, si); |
| 328 |
} |
| 329 |
else |
| 330 |
{ |
| 331 |
// probably ECONNRESET or somesuch |
| 332 |
slog (L_DEBUG, _("%s: %s"), (const char *)si, strerror (errno)); |
| 333 |
} |
| 334 |
|
| 335 |
delete pkt; |
| 336 |
} |
| 337 |
else if (revents & POLLHUP) |
| 338 |
{ |
| 339 |
// this cannot ;) happen on udp sockets |
| 340 |
slog (L_ERR, _("FATAL: POLLHUP on ipv4 fd, terminating.")); |
| 341 |
exit (1); |
| 342 |
} |
| 343 |
else |
| 344 |
{ |
| 345 |
slog (L_ERR, |
| 346 |
_("FATAL: unknown revents %08x in socket, terminating\n"), |
| 347 |
revents); |
| 348 |
exit (1); |
| 349 |
} |
| 350 |
} |
| 351 |
|
| 352 |
void |
| 353 |
vpn::tap_ev (io_watcher &w, short revents) |
| 354 |
{ |
| 355 |
if (revents & POLLIN) |
| 356 |
{ |
| 357 |
/* process data */ |
| 358 |
tap_packet *pkt; |
| 359 |
|
| 360 |
pkt = tap->recv (); |
| 361 |
|
| 362 |
int dst = mac2id (pkt->dst); |
| 363 |
int src = mac2id (pkt->src); |
| 364 |
|
| 365 |
if (src != THISNODE->id) |
| 366 |
{ |
| 367 |
slog (L_ERR, _("FATAL: tap packet not originating on current node received, terminating.")); |
| 368 |
exit (1); |
| 369 |
} |
| 370 |
|
| 371 |
if (dst == THISNODE->id) |
| 372 |
{ |
| 373 |
slog (L_ERR, _("FATAL: tap packet destined for current node received, terminating.")); |
| 374 |
exit (1); |
| 375 |
} |
| 376 |
|
| 377 |
if (dst > conns.size ()) |
| 378 |
slog (L_ERR, _("tap packet for unknown node %d received, ignoring."), dst); |
| 379 |
else |
| 380 |
{ |
| 381 |
if (dst) |
| 382 |
{ |
| 383 |
// unicast |
| 384 |
if (dst != THISNODE->id) |
| 385 |
conns[dst - 1]->inject_data_packet (pkt); |
| 386 |
} |
| 387 |
else |
| 388 |
{ |
| 389 |
// broadcast, first check router, then self, then english |
| 390 |
connection *router = find_router (); |
| 391 |
|
| 392 |
if (router) |
| 393 |
router->inject_data_packet (pkt, true); |
| 394 |
else |
| 395 |
for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
| 396 |
if ((*c)->conf != THISNODE) |
| 397 |
(*c)->inject_data_packet (pkt); |
| 398 |
} |
| 399 |
} |
| 400 |
|
| 401 |
delete pkt; |
| 402 |
} |
| 403 |
else if (revents & (POLLHUP | POLLERR)) |
| 404 |
{ |
| 405 |
slog (L_ERR, _("FATAL: POLLHUP or POLLERR on network device fd, terminating.")); |
| 406 |
exit (1); |
| 407 |
} |
| 408 |
else |
| 409 |
abort (); |
| 410 |
} |
| 411 |
|
| 412 |
void |
| 413 |
vpn::event_cb (time_watcher &w) |
| 414 |
{ |
| 415 |
if (events) |
| 416 |
{ |
| 417 |
if (events & EVENT_SHUTDOWN) |
| 418 |
{ |
| 419 |
slog (L_INFO, _("preparing shutdown...")); |
| 420 |
|
| 421 |
shutdown_all (); |
| 422 |
|
| 423 |
remove_pid (pidfilename); |
| 424 |
|
| 425 |
slog (L_INFO, _("terminating")); |
| 426 |
|
| 427 |
exit (0); |
| 428 |
} |
| 429 |
|
| 430 |
if (events & EVENT_RECONNECT) |
| 431 |
{ |
| 432 |
slog (L_INFO, _("forced reconnect")); |
| 433 |
|
| 434 |
reconnect_all (); |
| 435 |
} |
| 436 |
|
| 437 |
events = 0; |
| 438 |
} |
| 439 |
|
| 440 |
w.at = TSTAMP_CANCEL; |
| 441 |
} |
| 442 |
|
| 443 |
void |
| 444 |
vpn::shutdown_all () |
| 445 |
{ |
| 446 |
for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
| 447 |
(*c)->shutdown (); |
| 448 |
} |
| 449 |
|
| 450 |
void |
| 451 |
vpn::reconnect_all () |
| 452 |
{ |
| 453 |
for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
| 454 |
delete *c; |
| 455 |
|
| 456 |
conns.clear (); |
| 457 |
|
| 458 |
connection_init (); |
| 459 |
|
| 460 |
for (configuration::node_vector::iterator i = conf.nodes.begin (); |
| 461 |
i != conf.nodes.end (); ++i) |
| 462 |
{ |
| 463 |
connection *conn = new connection (this); |
| 464 |
|
| 465 |
conn->conf = *i; |
| 466 |
conns.push_back (conn); |
| 467 |
|
| 468 |
conn->establish_connection (); |
| 469 |
} |
| 470 |
} |
| 471 |
|
| 472 |
connection *vpn::find_router () |
| 473 |
{ |
| 474 |
u32 prio = 0; |
| 475 |
connection *router = 0; |
| 476 |
|
| 477 |
for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i) |
| 478 |
{ |
| 479 |
connection *c = *i; |
| 480 |
|
| 481 |
if (c->conf->routerprio > prio |
| 482 |
&& c->connectmode == conf_node::C_ALWAYS |
| 483 |
&& c->conf != THISNODE |
| 484 |
&& c->ictx && c->octx) |
| 485 |
{ |
| 486 |
prio = c->conf->routerprio; |
| 487 |
router = c; |
| 488 |
} |
| 489 |
} |
| 490 |
|
| 491 |
return router; |
| 492 |
} |
| 493 |
|
| 494 |
void vpn::connect_request (int id) |
| 495 |
{ |
| 496 |
connection *c = find_router (); |
| 497 |
|
| 498 |
if (c) |
| 499 |
c->connect_request (id); |
| 500 |
//else // does not work, because all others must connect to the same router |
| 501 |
// // no router found, aggressively connect to all routers |
| 502 |
// for (conns_vector::iterator i = conns.begin (); i != conns.end (); ++i) |
| 503 |
// if ((*i)->conf->routerprio) |
| 504 |
// (*i)->establish_connection (); |
| 505 |
} |
| 506 |
|
| 507 |
void |
| 508 |
connection::dump_status () |
| 509 |
{ |
| 510 |
slog (L_NOTICE, _("node %s (id %d)"), conf->nodename, conf->id); |
| 511 |
slog (L_NOTICE, _(" connectmode %d (%d) / sockaddr %s / minor %d"), |
| 512 |
connectmode, conf->connectmode, (const char *)si, (int)prot_minor); |
| 513 |
slog (L_NOTICE, _(" ictx/octx %08lx/%08lx / oseqno %d / retry_cnt %d"), |
| 514 |
(long)ictx, (long)octx, (int)oseqno, (int)retry_cnt); |
| 515 |
slog (L_NOTICE, _(" establish_conn %ld / rekey %ld / keepalive %ld"), |
| 516 |
(long)(establish_connection.at), (long)(rekey.at), (long)(keepalive.at)); |
| 517 |
} |
| 518 |
|
| 519 |
void |
| 520 |
vpn::dump_status () |
| 521 |
{ |
| 522 |
slog (L_NOTICE, _("BEGIN status dump (%ld)"), (long)NOW); |
| 523 |
|
| 524 |
for (conns_vector::iterator c = conns.begin (); c != conns.end (); ++c) |
| 525 |
(*c)->dump_status (); |
| 526 |
|
| 527 |
slog (L_NOTICE, _("END status dump")); |
| 528 |
} |
| 529 |
|
| 530 |
vpn::vpn (void) |
| 531 |
: event(this, &vpn::event_cb) |
| 532 |
, udpv4_ev_watcher(this, &vpn::udpv4_ev) |
| 533 |
, ipv4_ev_watcher (this, &vpn::ipv4_ev) |
| 534 |
, tap_ev_watcher (this, &vpn::tap_ev) |
| 535 |
#if ENABLE_TCP |
| 536 |
, tcpv4_ev_watcher(this, &vpn::tcpv4_ev) |
| 537 |
#endif |
| 538 |
{ |
| 539 |
} |
| 540 |
|
| 541 |
vpn::~vpn () |
| 542 |
{ |
| 543 |
} |
| 544 |
|
