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Comparing gvpe/src/vpn_tcp.C (file contents):
Revision 1.2 by pcg, Sun Apr 6 18:12:18 2003 UTC vs.
Revision 1.19 by pcg, Tue Nov 13 02:12:08 2007 UTC

1/* 1/*
2 vpn_tcp.C -- handle the tcp part of the protocol. 2 vpn_tcp.C -- handle the tcp part of the protocol.
3 Copyright (C) 2003-2007 Marc Lehmann <gvpe@schmorp.de>
3 4
5 This file is part of GVPE.
6
4 This program is free software; you can redistribute it and/or modify 7 GVPE is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by 8 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 9 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version. 10 (at your option) any later version.
8 11
9 This program is distributed in the hope that it will be useful, 12 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details. 15 GNU General Public License for more details.
13 16
14 You should have received a copy of the GNU General Public License 17 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software 18 along with gvpe; if not, write to the Free Software
16 Foundation, Inc. 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 19 Foundation, Inc. 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17*/ 20*/
18 21
19#include "config.h" 22#include "config.h"
20 23
21#if ENABLE_TCP 24#if ENABLE_TCP
22 25
23// tcp processing is extremely ugly, since the vpe protocol is simply 26// tcp processing is extremely ugly, since the gvpe protocol is simply
24// designed for unreliable datagram networks. tcp is implemented by 27// designed for unreliable datagram networks. tcp is implemented by
25// multiplexing packets over tcp. errors are completely ignored, as we 28// multiplexing packets over tcp. errors are completely ignored, as we
26// rely on the higher level protocol to time out and reconnect. 29// rely on the higher level layers to time out and reconnect.
27 30
28#include <cstring> 31#include <cstring>
29 32
30#include <sys/types.h> 33#include <sys/types.h>
31#include <sys/socket.h> 34#include <sys/socket.h>
32#include <sys/poll.h>
33#include <sys/wait.h> 35#include <sys/wait.h>
34#include <netinet/in.h>
35#include <sys/uio.h> 36#include <sys/uio.h>
36#include <arpa/inet.h>
37#include <errno.h> 37#include <errno.h>
38#include <time.h> 38#include <time.h>
39#include <unistd.h> 39#include <unistd.h>
40#include <fcntl.h>
40 41
41#include <map> 42#include <map>
42#include <unistd.h> 43
43#include <fcntl.h> 44#include "netcompat.h"
44#include <sys/poll.h>
45 45
46#include "vpn.h" 46#include "vpn.h"
47
48#if ENABLE_HTTP_PROXY
49# include "conf.h"
50#endif
47 51
48struct tcp_connection; 52struct tcp_connection;
49 53
50struct lt_sockinfo 54struct lt_sockinfo
51{ 55{
… …
54 return *a < *b; 58 return *a < *b;
55 } 59 }
56}; 60};
57 61
58struct tcp_si_map : public map<const sockinfo *, tcp_connection *, lt_sockinfo> { 62struct tcp_si_map : public map<const sockinfo *, tcp_connection *, lt_sockinfo> {
59 void cleaner_cb (time_watcher &w); time_watcher cleaner; 63 void cleaner_cb (ev::timer &w, int revents); ev::timer cleaner;
60 64
61 tcp_si_map () 65 tcp_si_map ()
62 : cleaner(this, &tcp_si_map::cleaner_cb) 66 : cleaner(this, &tcp_si_map::cleaner_cb)
63 { 67 {
64 cleaner.start (0); 68 cleaner.start (::conf.keepalive / 2, ::conf.keepalive / 2);
65 } 69 }
70
66} tcp_si; 71} tcp_si;
67 72
68struct tcp_connection : io_watcher { 73struct tcp_connection : ev::io {
69 tstamp last_activity; 74 tstamp last_activity;
70 const sockinfo si; 75 const sockinfo si;
71 vpn &v; 76 vpn &v;
72 bool active; // this connection has been actively established 77 bool active; // this connection has been actively established
73 enum { ERROR, IDLE, CONNECTING, ESTABLISHED } state; 78 enum { ERROR, IDLE, CONNECTING, CONNECTING_PROXY, ESTABLISHED } state;
74 79
75 vpn_packet *r_pkt; 80 vpn_packet *r_pkt;
76 u32 r_len, r_ofs; 81 u32 r_len, r_ofs;
77 82
83 vpn_packet *w_pkt;
84 u32 w_len, w_ofs;
85
86#if ENABLE_HTTP_PROXY
87 char *proxy_req;
88 int proxy_req_len;
89#endif
90
78 void tcpv4_ev (io_watcher &w, short revents); 91 void tcpv4_ev (ev::io &w, int revents);
79 92
80 bool send_packet (vpn_packet *pkt, int tos); 93 bool send_packet (vpn_packet *pkt, int tos);
94 bool write_packet ();
81 95
82 void error (); // abort conenction && cleanup 96 void error (); // abort conenction && cleanup
83 97
84 operator tcp_si_map::value_type() 98 operator tcp_si_map::value_type()
85 { 99 {
86 return tcp_si_map::value_type (&si, this); 100 return tcp_si_map::value_type (&si, this);
87 } 101 }
88 102
89 tcp_connection (int fd_, const sockinfo &si_, vpn &v_); 103 tcp_connection (int fd_, const sockinfo &si_, vpn &v_);
90 ~tcp_connection (); 104 ~tcp_connection ();
91}; 105};
92 106
93void tcp_si_map::cleaner_cb (time_watcher &w) 107void tcp_si_map::cleaner_cb (ev::timer &w, int revents)
94{ 108{
95 w.at = NOW + 600;
96 tstamp to = NOW - ::conf.keepalive - 30 - 60; 109 tstamp to = ev::ev_now () - ::conf.keepalive - 30 - 60;
97 110
98 for (iterator i = begin (); i != end(); ) 111 for (iterator i = begin (); i != end(); )
99 if (i->second->last_activity >= to) 112 if (i->second->last_activity >= to)
100 ++i; 113 ++i;
101 else 114 else
102 { 115 {
116 delete i->second;
103 erase (i); 117 erase (i);
104 i = begin (); 118 i = begin ();
105 } 119 }
106} 120}
107 121
108void 122void
109vpn::tcpv4_ev (io_watcher &w, short revents) 123vpn::tcpv4_ev (ev::io &w, int revents)
110{ 124{
111 if (revents & (POLLIN | POLLERR)) 125 if (revents & EV_READ)
112 { 126 {
113 struct sockaddr_in sa; 127 struct sockaddr_in sa;
114 socklen_t sa_len = sizeof (sa); 128 socklen_t sa_len = sizeof (sa);
115 int len; 129 int len;
116 130
117 int fd = accept (w.fd, (sockaddr *)&sa, &sa_len); 131 int fd = accept (w.fd, (sockaddr *)&sa, &sa_len);
118 132
119 if (fd >= 0) 133 if (fd >= 0)
120 { 134 {
135 fcntl (fd, F_SETFL, O_NONBLOCK);
136 fcntl (fd, F_SETFD, FD_CLOEXEC);
137
121 sockinfo si(sa, PROT_TCPv4); 138 sockinfo si(sa, PROT_TCPv4);
122 139
123 slog (L_DEBUG, _("%s: accepted tcp connection"), (const char *)si);//D 140 slog (L_DEBUG, _("%s: accepted tcp connection"), (const char *)si);//D
124
125 fcntl (fd, F_SETFL, O_NONBLOCK);
126 141
127 tcp_connection *i = new tcp_connection (fd, si, *this); 142 tcp_connection *i = new tcp_connection (fd, si, *this);
128 tcp_si.insert (*i); 143 tcp_si.insert (*i);
129 } 144 }
130 } 145 }
… …
146 i = info->second; 161 i = info->second;
147 162
148 return i->send_packet (pkt, tos); 163 return i->send_packet (pkt, tos);
149} 164}
150 165
166bool
167tcp_connection::write_packet ()
168{
169 ssize_t len;
170
171 if (w_ofs < 2)
172 {
173 u16 plen = htons (w_pkt->len);
174
175 iovec vec[2];
176 //TODO: char* is the right type? hardly...
177 vec[0].iov_base = (char *)((u8 *)&plen) + w_ofs;
178 vec[0].iov_len = 2 - w_ofs;
179 vec[1].iov_base = (char *)&((*w_pkt)[0]);
180 vec[1].iov_len = w_len - 2;
181
182 len = writev (fd, vec, 2);
183 }
184 else
185 len = write (fd, &((*w_pkt)[w_ofs - 2]), w_len);
186
187 if (len > 0)
188 {
189 w_ofs += len;
190 w_len -= len;
191
192 return w_len == 0;
193 }
194 else if (len < 0 && (errno == EAGAIN || errno == EINTR))
195 return false;
196 else
197 {
198 error ();
199 return false;
200 }
201}
202
203void
204tcp_connection::tcpv4_ev (ev::io &w, int revents)
205{
206 last_activity = ev::ev_now ();
207
208 if (revents & EV_WRITE)
209 {
210 if (state == CONNECTING)
211 {
212 state = ESTABLISHED;
213 set (EV_READ);
214#if ENABLE_HTTP_PROXY
215 if (::conf.proxy_host && ::conf.proxy_port)
216 {
217 state = CONNECTING_PROXY;
218
219 if (write (fd, proxy_req, proxy_req_len) == 0)
220 {
221 error ();
222 return;
223 }
224
225 free (proxy_req); proxy_req = 0;
226 }
227#endif
228 }
229 else if (state == ESTABLISHED)
230 {
231 if (w_pkt)
232 {
233 if (write_packet ())
234 {
235 delete w_pkt; w_pkt = 0;
236
237 set (EV_READ);
238 }
239 }
240 else
241 set (EV_READ);
242 }
243 else
244 set (EV_READ);
245 }
246
247 if (revents & EV_READ)
248 {
249 if (state == ESTABLISHED)
250 for (;;)
251 {
252 if (!r_pkt)
253 {
254 r_pkt = new vpn_packet;
255 r_ofs = 0;
256 r_len = 2; // header
257 }
258
259 ssize_t len = read (fd, &((*r_pkt)[r_ofs < 2 ? r_ofs : r_ofs - 2]), r_len);
260
261 if (len > 0)
262 {
263 r_len -= len;
264 r_ofs += len;
265
266 if (r_len == 0)
267 {
268 if (r_ofs == 2)
269 {
270 r_len = ntohs (*(u16 *)&((*r_pkt)[0]));
271 r_pkt->len = r_len;
272
273 if (r_len > 0 && r_len < MAXSIZE)
274 continue;
275 }
276 else
277 {
278 v.recv_vpn_packet (r_pkt, si);
279 delete r_pkt;
280 r_pkt = 0;
281
282 continue;
283 }
284 }
285 else
286 break;
287 }
288 else if (len < 0 && (errno == EINTR || errno == EAGAIN))
289 break;
290
291 // len == 0 <-> EOF
292 error ();
293 break;
294 }
295#if ENABLE_HTTP_PROXY
296 else if (state == CONNECTING_PROXY)
297 {
298 fcntl (fd, F_SETFL, 0);
299 char r[1024];
300 int i;
301 bool emptyline = false;
302
303 // we do a blocking read of the response, to hell with it
304 for (i = 0; i < 1023; i++)
305 {
306 int l = read (fd, &r[i], 1);
307
308 if (l <= 0)
309 {
310 error ();
311 return;
312 }
313
314 if (r[i] == '\012')
315 {
316 if (emptyline)
317 break;
318 else
319 emptyline = true;
320 }
321 else if (r[i] != '\015')
322 emptyline = false;
323 }
324
325 fcntl (fd, F_SETFL, O_NONBLOCK);
326
327 if (i < 12)
328 {
329 slog (L_ERR, _("(%s): unable to do proxy-forwarding, short response"),
330 (const char *)si);
331 error ();
332 }
333 else if (r[0] != 'H' || r[1] != 'T' || r[2] != 'T' || r[3] != 'P' || r[4] != '/'
334 || r[5] != '1' // http-major
335 || r[9] != '2') // response
336 {
337 slog (L_ERR, _("(%s): malformed or unexpected proxy response (%.12s)"),
338 (const char *)si, r);
339 error ();
340 }
341 else
342 state = ESTABLISHED;
343 }
344#endif
345 }
346}
347
348bool
349tcp_connection::send_packet (vpn_packet *pkt, int tos)
350{
351 last_activity = ev::ev_now ();
352
353 if (state == IDLE)
354 {
355 // woaw, the first lost packet ;)
356 fd = socket (PF_INET, SOCK_STREAM, IPPROTO_TCP);
357
358 if (fd >= 0)
359 {
360 const sockinfo *csi = &si;
361
362#if ENABLE_HTTP_PROXY
363 sockinfo psi;
364
365 if (::conf.proxy_host && ::conf.proxy_port)
366 {
367 psi.set (::conf.proxy_host, ::conf.proxy_port, PROT_TCPv4);
368
369 if (psi.valid ())
370 {
371 csi = &psi;
372
373 proxy_req_len = asprintf (&proxy_req,
374 "CONNECT %s:%d HTTP/1.0\015\012"
375 "%s%s%s" // optional proxy-auth
376 "\015\012",
377 si.ntoa (),
378 ntohs (si.port),
379 ::conf.proxy_auth ? "Proxy-Authorization: Basic " : "",
380 ::conf.proxy_auth ? ::conf.proxy_auth : "",
381 ::conf.proxy_auth ? "\015\012" : "");
382
383 }
384 else
385 slog (L_ERR, _("unable to resolve http proxy hostname '%s', trying direct"),
386 ::conf.proxy_host);
387 }
388#endif
389
390 fcntl (fd, F_SETFL, O_NONBLOCK);
391
392 if (connect (fd, csi->sav4 (), csi->salenv4 ()) >= 0
393 || errno == EINPROGRESS)
394 {
395 fcntl (fd, F_SETFL, O_NONBLOCK);
396 fcntl (fd, F_SETFD, FD_CLOEXEC);
397
398 state = CONNECTING;
399 start (fd, EV_WRITE);
400 }
401 else
402 close (fd);
403 }
404 }
405 else if (state == ESTABLISHED)
406 {
407 // drop packet if the tcp write buffer is full. this *is* the
408 // right thing to do, not using tcp *is* the right thing to do.
409 if (!w_pkt)
410 {
411 // how this maps to the underlying tcp packets we don't know
412 // and we don't care. at least we tried ;)
413#if defined(SOL_IP) && defined(IP_TOS)
414 setsockopt (fd, SOL_IP, IP_TOS, &tos, sizeof tos);
415#endif
416
417 w_pkt = pkt;
418 w_ofs = 0;
419 w_len = pkt->len + 2; // length + size header
420
421 if (write_packet ())
422 w_pkt = 0;
423 else
424 {
425 w_pkt = new vpn_packet;
426 w_pkt->set (*pkt);
427
428 set (EV_READ | EV_WRITE);
429 }
430 }
431 }
432
433 return state != ERROR;
434}
435
151void tcp_connection::error () 436void tcp_connection::error ()
152{ 437{
438 stop ();
439
153 if (fd >= 0) 440 if (fd >= 0)
154 { 441 {
155 close (fd); 442 close (fd);
156 fd = -1; 443 fd = -1;
157 } 444 }
158 445
159 delete r_pkt; 446 delete r_pkt; r_pkt = 0;
447 delete w_pkt; w_pkt = 0;
448#if ENABLE_HTTP_PROXY
449 free (proxy_req); proxy_req = 0;
450#endif
451
452 state = active ? IDLE : ERROR;
453}
454
455tcp_connection::tcp_connection (int fd_, const sockinfo &si_, vpn &v_)
456: v(v_), si(si_), ev::io(this, &tcp_connection::tcpv4_ev)
457{
458 last_activity = ev::ev_now ();
160 r_pkt = 0; 459 r_pkt = 0;
161
162 stop ();
163 state = active ? IDLE : ERROR;
164}
165
166void
167tcp_connection::tcpv4_ev (io_watcher &w, short revents)
168{
169 last_activity = NOW;
170
171 if (revents & (POLLERR | POLLHUP))
172 error ();
173 else if (revents & POLLOUT && state == CONNECTING)
174 {
175 state = ESTABLISHED;
176 set (POLLIN);
177 }
178
179 else if (revents & POLLIN)
180 {
181 for (;;)
182 {
183 if (!r_pkt)
184 {
185 r_pkt = new vpn_packet;
186 r_ofs = 0;
187 r_len = 2; // header
188 }
189
190 ssize_t len = read (fd, &((*r_pkt)[r_ofs < 2 ? r_ofs : r_ofs - 2]), r_len);
191
192 if (len > 0)
193 {
194 r_len -= len;
195 r_ofs += len;
196
197 if (r_len == 0)
198 {
199 if (r_ofs == 2)
200 {
201 r_len = ntohs (*(u16 *)&((*r_pkt)[0]));
202 r_pkt->len = r_len;
203
204 if (r_len > 0 && r_len < MAXSIZE)
205 continue;
206 }
207 else
208 {
209 v.recv_vpn_packet (r_pkt, si);
210 delete r_pkt;
211 r_pkt = 0;
212
213 continue;
214 }
215 }
216
217 }
218 else if (len < 0 && (errno == EINTR || errno == EAGAIN))
219 return;
220
221 error ();
222 return;
223 }
224 }
225}
226
227bool
228tcp_connection::send_packet (vpn_packet *pkt, int tos)
229{
230 last_activity = NOW;
231
232 if (state == IDLE)
233 {
234 // woaw, the first lost packet ;)
235 fd = socket (PF_INET, SOCK_STREAM, IPPROTO_TCP);
236
237 if (fd >= 0)
238 {
239 fcntl (fd, F_SETFL, O_NONBLOCK);
240
241 if (connect (fd, si.sav4 (), si.salenv4 ()) >= 0
242 || errno == EINPROGRESS)
243 {
244 state = CONNECTING;
245 start (fd, POLLOUT);
246 }
247 else
248 close (fd);
249 }
250 }
251 else if (state == ESTABLISHED)
252 {
253 // how this maps to the underlying tcp packet we don't know
254 // and we don't care. at least we tried ;)
255 setsockopt (fd, SOL_IP, IP_TOS, &tos, sizeof tos);
256
257 // we use none of the advantages of tcp; if an error occurs, just drop
258 // (this happens when a tcp connection gets stuck, too, which might not be
259 // the wisest thing to do.. either drop packet (too late) or make sure
260 // it gets delivered)
261 u16 len = htons (pkt->len);
262
263 iovec vec[2];
264 vec[0].iov_base = &len;
265 vec[0].iov_len = sizeof len;
266 vec[1].iov_base = &((*pkt)[0]);
267 vec[1].iov_len = pkt->len;
268
269 if (sizeof (u16) + pkt->len != writev (fd, vec, 2))
270 error ();
271 }
272
273 return state != ERROR;
274}
275
276tcp_connection::tcp_connection (int fd_, const sockinfo &si_, vpn &v_)
277: v(v_), si(si_), io_watcher(this, &tcp_connection::tcpv4_ev)
278{
279 last_activity = NOW;
280 r_pkt = 0; 460 w_pkt = 0;
281 fd = fd_; 461 fd = fd_;
462#if ENABLE_HTTP_PROXY
463 proxy_req = 0;
464#endif
282 465
283 if (fd < 0) 466 if (fd < 0)
284 { 467 {
285 active = true; 468 active = true;
286 state = IDLE; 469 state = IDLE;
287 } 470 }
288 else 471 else
289 { 472 {
290 active = false; 473 active = false;
291 state = ESTABLISHED; 474 state = ESTABLISHED;
292 start (fd, POLLIN); 475 start (fd, EV_READ);
293 } 476 }
294} 477}
295 478
296tcp_connection::~tcp_connection () 479tcp_connection::~tcp_connection ()
297{ 480{

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