| 1 |
/* |
| 2 |
vpn_tcp.C -- handle the tcp part of the protocol. |
| 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 |
|
| 21 |
#if ENABLE_TCP |
| 22 |
|
| 23 |
// tcp processing is extremely ugly, since the vpe protocol is simply |
| 24 |
// designed for unreliable datagram networks. tcp is implemented by |
| 25 |
// multiplexing packets over tcp. errors are completely ignored, as we |
| 26 |
// rely on the higher level protocol to time out and reconnect. |
| 27 |
|
| 28 |
#include <cstring> |
| 29 |
|
| 30 |
#include <sys/types.h> |
| 31 |
#include <sys/socket.h> |
| 32 |
#include <sys/poll.h> |
| 33 |
#include <sys/wait.h> |
| 34 |
#include <sys/uio.h> |
| 35 |
#include <errno.h> |
| 36 |
#include <time.h> |
| 37 |
#include <unistd.h> |
| 38 |
|
| 39 |
#include <map> |
| 40 |
#include <unistd.h> |
| 41 |
#include <fcntl.h> |
| 42 |
#include <sys/poll.h> |
| 43 |
|
| 44 |
#include "netcompat.h" |
| 45 |
|
| 46 |
#include "vpn.h" |
| 47 |
|
| 48 |
#if ENABLE_HTTP_PROXY |
| 49 |
# include "conf.h" |
| 50 |
#endif |
| 51 |
|
| 52 |
struct tcp_connection; |
| 53 |
|
| 54 |
struct lt_sockinfo |
| 55 |
{ |
| 56 |
bool operator()(const sockinfo *a, const sockinfo *b) const |
| 57 |
{ |
| 58 |
return *a < *b; |
| 59 |
} |
| 60 |
}; |
| 61 |
|
| 62 |
struct tcp_si_map : public map<const sockinfo *, tcp_connection *, lt_sockinfo> { |
| 63 |
void cleaner_cb (time_watcher &w); time_watcher cleaner; |
| 64 |
|
| 65 |
tcp_si_map () |
| 66 |
: cleaner(this, &tcp_si_map::cleaner_cb) |
| 67 |
{ |
| 68 |
cleaner.start (0); |
| 69 |
} |
| 70 |
} tcp_si; |
| 71 |
|
| 72 |
struct tcp_connection : io_watcher { |
| 73 |
tstamp last_activity; |
| 74 |
const sockinfo si; |
| 75 |
vpn &v; |
| 76 |
bool active; // this connection has been actively established |
| 77 |
enum { ERROR, IDLE, CONNECTING, CONNECTING_PROXY, ESTABLISHED } state; |
| 78 |
|
| 79 |
vpn_packet *r_pkt; |
| 80 |
u32 r_len, r_ofs; |
| 81 |
|
| 82 |
vpn_packet *w_pkt; |
| 83 |
u32 w_len, w_ofs; |
| 84 |
|
| 85 |
#if ENABLE_HTTP_PROXY |
| 86 |
char *proxy_req; |
| 87 |
int proxy_req_len; |
| 88 |
#endif |
| 89 |
|
| 90 |
void tcpv4_ev (io_watcher &w, short revents); |
| 91 |
|
| 92 |
bool send_packet (vpn_packet *pkt, int tos); |
| 93 |
bool write_packet (); |
| 94 |
|
| 95 |
void error (); // abort conenction && cleanup |
| 96 |
|
| 97 |
operator tcp_si_map::value_type() |
| 98 |
{ |
| 99 |
return tcp_si_map::value_type (&si, this); |
| 100 |
} |
| 101 |
|
| 102 |
tcp_connection (int fd_, const sockinfo &si_, vpn &v_); |
| 103 |
~tcp_connection (); |
| 104 |
}; |
| 105 |
|
| 106 |
void tcp_si_map::cleaner_cb (time_watcher &w) |
| 107 |
{ |
| 108 |
w.at = NOW + 600; |
| 109 |
tstamp to = NOW - ::conf.keepalive - 30 - 60; |
| 110 |
|
| 111 |
for (iterator i = begin (); i != end(); ) |
| 112 |
if (i->second->last_activity >= to) |
| 113 |
++i; |
| 114 |
else |
| 115 |
{ |
| 116 |
erase (i); |
| 117 |
i = begin (); |
| 118 |
} |
| 119 |
} |
| 120 |
|
| 121 |
void |
| 122 |
vpn::tcpv4_ev (io_watcher &w, short revents) |
| 123 |
{ |
| 124 |
if (revents & (POLLIN | POLLERR)) |
| 125 |
{ |
| 126 |
struct sockaddr_in sa; |
| 127 |
socklen_t sa_len = sizeof (sa); |
| 128 |
int len; |
| 129 |
|
| 130 |
int fd = accept (w.fd, (sockaddr *)&sa, &sa_len); |
| 131 |
|
| 132 |
if (fd >= 0) |
| 133 |
{ |
| 134 |
sockinfo si(sa, PROT_TCPv4); |
| 135 |
|
| 136 |
slog (L_DEBUG, _("%s: accepted tcp connection"), (const char *)si);//D |
| 137 |
|
| 138 |
fcntl (fd, F_SETFL, O_NONBLOCK); |
| 139 |
|
| 140 |
tcp_connection *i = new tcp_connection (fd, si, *this); |
| 141 |
tcp_si.insert (*i); |
| 142 |
} |
| 143 |
} |
| 144 |
} |
| 145 |
|
| 146 |
bool |
| 147 |
vpn::send_tcpv4_packet (vpn_packet *pkt, const sockinfo &si, int tos) |
| 148 |
{ |
| 149 |
tcp_si_map::iterator info = tcp_si.find (&si); |
| 150 |
|
| 151 |
tcp_connection *i; |
| 152 |
|
| 153 |
if (info == tcp_si.end ()) |
| 154 |
{ |
| 155 |
i = new tcp_connection (-1, si, *this); |
| 156 |
tcp_si.insert (*i); |
| 157 |
} |
| 158 |
else |
| 159 |
i = info->second; |
| 160 |
|
| 161 |
return i->send_packet (pkt, tos); |
| 162 |
} |
| 163 |
|
| 164 |
bool |
| 165 |
tcp_connection::write_packet () |
| 166 |
{ |
| 167 |
ssize_t len; |
| 168 |
|
| 169 |
if (w_ofs < 2) |
| 170 |
{ |
| 171 |
u16 plen = htons (w_pkt->len); |
| 172 |
|
| 173 |
iovec vec[2]; |
| 174 |
//TODO: char* is the right type? hardly... |
| 175 |
vec[0].iov_base = (char *)((u8 *)&plen) + w_ofs; |
| 176 |
vec[0].iov_len = 2 - w_ofs; |
| 177 |
vec[1].iov_base = (char *)&((*w_pkt)[0]); |
| 178 |
vec[1].iov_len = w_len - 2; |
| 179 |
|
| 180 |
len = writev (fd, vec, 2); |
| 181 |
} |
| 182 |
else |
| 183 |
len = write (fd, &((*w_pkt)[w_ofs - 2]), w_len); |
| 184 |
|
| 185 |
if (len > 0) |
| 186 |
{ |
| 187 |
w_ofs += len; |
| 188 |
w_len -= len; |
| 189 |
|
| 190 |
return w_len == 0; |
| 191 |
} |
| 192 |
else if (len < 0 && (errno == EAGAIN || errno == EINTR)) |
| 193 |
return false; |
| 194 |
else |
| 195 |
{ |
| 196 |
error (); |
| 197 |
return false; |
| 198 |
} |
| 199 |
} |
| 200 |
|
| 201 |
void |
| 202 |
tcp_connection::tcpv4_ev (io_watcher &w, short revents) |
| 203 |
{ |
| 204 |
last_activity = NOW; |
| 205 |
|
| 206 |
if (revents & (POLLERR | POLLHUP)) |
| 207 |
{ |
| 208 |
error (); |
| 209 |
return; |
| 210 |
} |
| 211 |
|
| 212 |
if (revents & POLLOUT) |
| 213 |
{ |
| 214 |
if (state == CONNECTING) |
| 215 |
{ |
| 216 |
state = ESTABLISHED; |
| 217 |
set (POLLIN); |
| 218 |
#if ENABLE_HTTP_PROXY |
| 219 |
if (::conf.proxy_host && ::conf.proxy_port) |
| 220 |
{ |
| 221 |
state = CONNECTING_PROXY; |
| 222 |
write (fd, proxy_req, proxy_req_len); |
| 223 |
free (proxy_req); proxy_req = 0; |
| 224 |
} |
| 225 |
#endif |
| 226 |
} |
| 227 |
else if (state == ESTABLISHED) |
| 228 |
{ |
| 229 |
if (w_pkt) |
| 230 |
{ |
| 231 |
if (write_packet ()) |
| 232 |
{ |
| 233 |
delete w_pkt; w_pkt = 0; |
| 234 |
|
| 235 |
set (POLLIN); |
| 236 |
} |
| 237 |
} |
| 238 |
else |
| 239 |
set (POLLIN); |
| 240 |
} |
| 241 |
else |
| 242 |
set (POLLIN); |
| 243 |
} |
| 244 |
|
| 245 |
if (revents & POLLIN) |
| 246 |
{ |
| 247 |
if (state == ESTABLISHED) |
| 248 |
for (;;) |
| 249 |
{ |
| 250 |
if (!r_pkt) |
| 251 |
{ |
| 252 |
r_pkt = new vpn_packet; |
| 253 |
r_ofs = 0; |
| 254 |
r_len = 2; // header |
| 255 |
} |
| 256 |
|
| 257 |
ssize_t len = read (fd, &((*r_pkt)[r_ofs < 2 ? r_ofs : r_ofs - 2]), r_len); |
| 258 |
|
| 259 |
if (len > 0) |
| 260 |
{ |
| 261 |
r_len -= len; |
| 262 |
r_ofs += len; |
| 263 |
|
| 264 |
if (r_len == 0) |
| 265 |
{ |
| 266 |
if (r_ofs == 2) |
| 267 |
{ |
| 268 |
r_len = ntohs (*(u16 *)&((*r_pkt)[0])); |
| 269 |
r_pkt->len = r_len; |
| 270 |
|
| 271 |
if (r_len > 0 && r_len < MAXSIZE) |
| 272 |
continue; |
| 273 |
} |
| 274 |
else |
| 275 |
{ |
| 276 |
v.recv_vpn_packet (r_pkt, si); |
| 277 |
delete r_pkt; |
| 278 |
r_pkt = 0; |
| 279 |
|
| 280 |
continue; |
| 281 |
} |
| 282 |
} |
| 283 |
else |
| 284 |
break; |
| 285 |
} |
| 286 |
else if (len < 0 && (errno == EINTR || errno == EAGAIN)) |
| 287 |
break; |
| 288 |
|
| 289 |
error (); |
| 290 |
break; |
| 291 |
} |
| 292 |
#if ENABLE_HTTP_PROXY |
| 293 |
else if (state == CONNECTING_PROXY) |
| 294 |
{ |
| 295 |
fcntl (fd, F_SETFL, 0); |
| 296 |
char r[1024]; |
| 297 |
int i; |
| 298 |
bool emptyline = false; |
| 299 |
|
| 300 |
// we do a blocking read of the response, to hell with it |
| 301 |
for (i = 0; i < 1023; i++) |
| 302 |
{ |
| 303 |
int l = read (fd, &r[i], 1); |
| 304 |
|
| 305 |
if (l <= 0) |
| 306 |
{ |
| 307 |
error (); |
| 308 |
return; |
| 309 |
} |
| 310 |
|
| 311 |
if (r[i] == '\012') |
| 312 |
{ |
| 313 |
if (emptyline) |
| 314 |
break; |
| 315 |
else |
| 316 |
emptyline = true; |
| 317 |
} |
| 318 |
else if (r[i] != '\015') |
| 319 |
emptyline = false; |
| 320 |
} |
| 321 |
|
| 322 |
fcntl (fd, F_SETFL, O_NONBLOCK); |
| 323 |
|
| 324 |
if (i < 12) |
| 325 |
{ |
| 326 |
slog (L_ERR, _("(%s): unable to do proxy-forwarding, short response"), |
| 327 |
(const char *)si); |
| 328 |
error (); |
| 329 |
} |
| 330 |
else if (r[0] != 'H' || r[1] != 'T' || r[2] != 'T' || r[3] != 'P' || r[4] != '/' |
| 331 |
|| r[5] != '1' // http-major |
| 332 |
|| r[9] != '2') // response |
| 333 |
{ |
| 334 |
slog (L_ERR, _("(%s): malformed or unexpected proxy response (%.12s)"), |
| 335 |
(const char *)si, r); |
| 336 |
error (); |
| 337 |
} |
| 338 |
else |
| 339 |
state = ESTABLISHED; |
| 340 |
} |
| 341 |
#endif |
| 342 |
} |
| 343 |
} |
| 344 |
|
| 345 |
bool |
| 346 |
tcp_connection::send_packet (vpn_packet *pkt, int tos) |
| 347 |
{ |
| 348 |
last_activity = NOW; |
| 349 |
|
| 350 |
if (state == IDLE) |
| 351 |
{ |
| 352 |
// woaw, the first lost packet ;) |
| 353 |
fd = socket (PF_INET, SOCK_STREAM, IPPROTO_TCP); |
| 354 |
|
| 355 |
if (fd >= 0) |
| 356 |
{ |
| 357 |
const sockinfo *csi = &si; |
| 358 |
|
| 359 |
#if ENABLE_HTTP_PROXY |
| 360 |
sockinfo psi; |
| 361 |
|
| 362 |
if (::conf.proxy_host && ::conf.proxy_port) |
| 363 |
{ |
| 364 |
psi.set (::conf.proxy_host, ::conf.proxy_port, PROT_TCPv4); |
| 365 |
|
| 366 |
if (psi.valid ()) |
| 367 |
{ |
| 368 |
csi = ψ |
| 369 |
|
| 370 |
proxy_req_len = asprintf (&proxy_req, |
| 371 |
"CONNECT %s:%d HTTP/1.0\015\012" |
| 372 |
"%s%s%s" // optional proxy-auth |
| 373 |
"\015\012", |
| 374 |
si.ntoa (), |
| 375 |
ntohs (si.port), |
| 376 |
::conf.proxy_auth ? "Proxy-Authorization: Basic " : "", |
| 377 |
::conf.proxy_auth ? ::conf.proxy_auth : "", |
| 378 |
::conf.proxy_auth ? "\015\012" : ""); |
| 379 |
|
| 380 |
} |
| 381 |
else |
| 382 |
slog (L_ERR, _("unable to resolve http proxy hostname '%s', trying direct"), |
| 383 |
::conf.proxy_host); |
| 384 |
} |
| 385 |
#endif |
| 386 |
|
| 387 |
fcntl (fd, F_SETFL, O_NONBLOCK); |
| 388 |
|
| 389 |
if (connect (fd, csi->sav4 (), csi->salenv4 ()) >= 0 |
| 390 |
|| errno == EINPROGRESS) |
| 391 |
{ |
| 392 |
state = CONNECTING; |
| 393 |
start (fd, POLLOUT); |
| 394 |
} |
| 395 |
else |
| 396 |
close (fd); |
| 397 |
} |
| 398 |
} |
| 399 |
else if (state == ESTABLISHED) |
| 400 |
{ |
| 401 |
// drop packet if the tcp write buffer is full. this *is* the |
| 402 |
// right thing to do, not using tcp *is* the right thing to do. |
| 403 |
if (!w_pkt) |
| 404 |
{ |
| 405 |
// how this maps to the underlying tcp packets we don't know |
| 406 |
// and we don't care. at least we tried ;) |
| 407 |
#if defined(SOL_IP) && defined(IP_TOS) |
| 408 |
setsockopt (fd, SOL_IP, IP_TOS, &tos, sizeof tos); |
| 409 |
#endif |
| 410 |
|
| 411 |
w_pkt = pkt; |
| 412 |
w_ofs = 0; |
| 413 |
w_len = pkt->len + 2; // length + size header |
| 414 |
|
| 415 |
if (write_packet ()) |
| 416 |
w_pkt = 0; |
| 417 |
else |
| 418 |
{ |
| 419 |
w_pkt = new vpn_packet; |
| 420 |
w_pkt->set (*pkt); |
| 421 |
|
| 422 |
set (POLLIN | POLLOUT); |
| 423 |
} |
| 424 |
} |
| 425 |
} |
| 426 |
|
| 427 |
return state != ERROR; |
| 428 |
} |
| 429 |
|
| 430 |
void tcp_connection::error () |
| 431 |
{ |
| 432 |
if (fd >= 0) |
| 433 |
{ |
| 434 |
close (fd); |
| 435 |
fd = -1; |
| 436 |
} |
| 437 |
|
| 438 |
delete r_pkt; r_pkt = 0; |
| 439 |
delete w_pkt; w_pkt = 0; |
| 440 |
#if ENABLE_HTTP_PROXY |
| 441 |
free (proxy_req); proxy_req = 0; |
| 442 |
#endif |
| 443 |
|
| 444 |
stop (); |
| 445 |
state = active ? IDLE : ERROR; |
| 446 |
} |
| 447 |
|
| 448 |
tcp_connection::tcp_connection (int fd_, const sockinfo &si_, vpn &v_) |
| 449 |
: v(v_), si(si_), io_watcher(this, &tcp_connection::tcpv4_ev) |
| 450 |
{ |
| 451 |
last_activity = NOW; |
| 452 |
r_pkt = 0; |
| 453 |
w_pkt = 0; |
| 454 |
fd = fd_; |
| 455 |
#if ENABLE_HTTP_PROXY |
| 456 |
proxy_req = 0; |
| 457 |
#endif |
| 458 |
|
| 459 |
if (fd < 0) |
| 460 |
{ |
| 461 |
active = true; |
| 462 |
state = IDLE; |
| 463 |
} |
| 464 |
else |
| 465 |
{ |
| 466 |
active = false; |
| 467 |
state = ESTABLISHED; |
| 468 |
start (fd, POLLIN); |
| 469 |
} |
| 470 |
} |
| 471 |
|
| 472 |
tcp_connection::~tcp_connection () |
| 473 |
{ |
| 474 |
error (); |
| 475 |
} |
| 476 |
|
| 477 |
#endif |
| 478 |
|
