chiark / gitweb /
Fix logrotate script.
[tripe] / pkstream.c
CommitLineData
07212ba4 1/* -*-c-*-
2 *
ef4a1ab7 3 * $Id: pkstream.c,v 1.2 2003/11/29 23:49:32 mdw Exp $
07212ba4 4 *
5 * Forwarding UDP packets over a stream
6 *
7 * (c) 2003 Straylight/Edgeware
8 */
9
10/*----- Licensing notice --------------------------------------------------*
11 *
12 * This file is part of Trivial IP Encryption (TrIPE).
13 *
14 * TrIPE is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * TrIPE is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with TrIPE; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 */
28
29/*----- Revision history --------------------------------------------------*
30 *
31 * $Log: pkstream.c,v $
ef4a1ab7 32 * Revision 1.2 2003/11/29 23:49:32 mdw
33 * Debianization.
34 *
07212ba4 35 * Revision 1.1 2003/04/23 12:53:28 mdw
36 * New pkstream program.
37 *
38 */
39
40/*----- Header files ------------------------------------------------------*/
41
42#include "config.h"
43
44#include <ctype.h>
45#include <errno.h>
46#include <stdio.h>
47#include <stdlib.h>
48#include <string.h>
49
50#include <sys/time.h>
51#include <sys/types.h>
52#include <unistd.h>
53#include <fcntl.h>
54#include <sys/uio.h>
55#include <sys/socket.h>
56#include <netinet/in.h>
57#include <arpa/inet.h>
58#include <netdb.h>
59
60#include <mLib/alloc.h>
61#include <mLib/bits.h>
62#include <mLib/dstr.h>
63#include <mLib/fdflags.h>
64#include <mLib/mdwopt.h>
65#include <mLib/quis.h>
66#include <mLib/report.h>
67#include <mLib/sel.h>
68#include <mLib/selpk.h>
69
70/*----- Data structures ---------------------------------------------------*/
71
72typedef struct pk {
73 struct pk *next; /* Next packet in the chain */
74 octet *p, *o; /* Buffer start and current posn */
75 size_t n; /* Size of packet remaining */
76} pk;
77
78typedef struct pkstream {
79 unsigned f; /* Flags... */
80#define PKF_FULL 1u /* Buffer is full: stop reading */
81 sel_file r, w; /* Read and write selectors */
82 pk *pks, **pk_tail; /* Packet queue */
83 size_t npk, szpk; /* Number and size of data */
84 selpk p; /* Packet parser */
85} pkstream;
86
87typedef struct connwait {
88 sel_file a; /* Selector */
89 struct sockaddr_in me; /* Who I'm meant to be */
90 struct in_addr peer; /* Who my peer is */
91} connwait;
92
93/*----- Static variables --------------------------------------------------*/
94
95static sel_state sel;
96static connwait cw;
97static int fd_udp;
98static size_t pk_nmax = 128, pk_szmax = 1024 * 1024;
99
100/*----- Main code ---------------------------------------------------------*/
101
102static int nonblockify(int fd)
103{
104 return (fdflags(fd, O_NONBLOCK, O_NONBLOCK, 0, 0));
105}
106
107static int cloexec(int fd)
108{
109 return (fdflags(fd, 0, 0, FD_CLOEXEC, FD_CLOEXEC));
110}
111
112static void dolisten(void);
113
114static void doclose(pkstream *p)
115{
116 pk *pk, *ppk;
117 close(p->w.fd);
118 close(p->p.reader.fd);
119 selpk_destroy(&p->p);
120 if (!(p->f & PKF_FULL))
121 sel_rmfile(&p->r);
122 if (p->npk)
123 sel_rmfile(&p->w);
124 for (pk = p->pks; pk; pk = ppk) {
125 ppk = pk->next;
126 xfree(pk->p);
127 xfree(pk);
128 }
129 xfree(p);
130 if (cw.me.sin_port != 0)
131 dolisten();
132 else
133 exit(0);
134}
135
136static void rdtcp(octet *b, size_t sz, pkbuf *pk, size_t *k, void *vp)
137{
138 pkstream *p = vp;
139 size_t pksz;
140
141 if (!sz) {
142 doclose(p);
143 return;
144 }
145 pksz = LOAD16(b);
146 if (pksz + 2 == sz) {
147 write(fd_udp, b + 2, pksz);
148 selpk_want(&p->p, 2);
149 } else {
150 selpk_want(&p->p, pksz + 2);
151 *k = sz;
152 }
153}
154
155static void wrtcp(int fd, unsigned mode, void *vp)
156{
157#define NPK 16
158 struct iovec iov[NPK];
159 pkstream *p = vp;
160 size_t i;
161 ssize_t n;
162 pk *pk, *ppk;
163
164 for (i = 0, pk = p->pks; i < NPK && pk; i++, pk = pk->next) {
165 iov[i].iov_base = pk->o;
166 iov[i].iov_len = pk->n;
167 }
168
169 if ((n = writev(fd, iov, i)) < 0) {
170 if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
171 return;
172 moan("couldn't write to TCP socket: %s", strerror(errno));
173 doclose(p);
174 return;
175 }
176
177 p->szpk -= n;
178 for (pk = p->pks; n && pk; pk = ppk) {
179 ppk = pk->next;
180 if (pk->n <= n) {
181 p->npk--;
182 n -= pk->n;
183 xfree(pk->p);
184 xfree(pk);
185 } else {
186 pk->n -= n;
187 pk->o += n;
188 break;
189 }
190 }
191 p->pks = pk;
192 if (!pk) {
193 p->pk_tail = &p->pks;
194 sel_rmfile(&p->w);
195 }
196 if ((p->f & PKF_FULL) && p->npk < pk_nmax && p->szpk < pk_szmax) {
197 p->f &= ~PKF_FULL;
198 sel_addfile(&p->r);
199 }
200}
201
202static void rdudp(int fd, unsigned mode, void *vp)
203{
204 octet buf[65536];
205 ssize_t n;
206 pkstream *p = vp;
207 pk *pk;
208
209 if ((n = read(fd, buf, sizeof(buf))) < 0) {
210 if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
211 return;
212 moan("couldn't read from UDP socket: %s", strerror(errno));
213 return;
214 }
215 pk = xmalloc(sizeof(*pk));
216 pk->next = 0;
217 pk->p = xmalloc(n + 2);
218 STORE16(pk->p, n);
219 memcpy(pk->p + 2, buf, n);
220 pk->o = pk->p;
221 pk->n = n + 2;
222 *p->pk_tail = pk;
223 p->pk_tail = &pk->next;
224 if (!p->npk)
225 sel_addfile(&p->w);
226 sel_force(&p->w);
227 p->npk++;
228 p->szpk += n + 2;
229 if (p->npk >= pk_nmax || p->szpk >= pk_szmax) {
230 sel_rmfile(&p->r);
231 p->f |= PKF_FULL;
232 }
233}
234
235static void dofwd(int fd_in, int fd_out)
236{
237 pkstream *p = xmalloc(sizeof(*p));
238 sel_initfile(&sel, &p->r, fd_udp, SEL_READ, rdudp, p);
239 sel_initfile(&sel, &p->w, fd_out, SEL_WRITE, wrtcp, p);
240 selpk_init(&p->p, &sel, fd_in, rdtcp, p);
241 selpk_want(&p->p, 2);
242 p->pks = 0;
243 p->pk_tail = &p->pks;
244 p->npk = p->szpk = 0;
245 p->f = 0;
246 sel_addfile(&p->r);
247}
248
249static void doaccept(int fd_s, unsigned mode, void *p)
250{
251 int fd;
252 struct sockaddr_in sin;
253 socklen_t sz = sizeof(sin);
254
255 if ((fd = accept(fd_s, (struct sockaddr *)&sin, &sz)) < 0) {
256 if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
257 return;
258 moan("couldn't accept incoming connection: %s", strerror(errno));
259 return;
260 }
261 if (cw.peer.s_addr != INADDR_ANY &&
262 cw.peer.s_addr != sin.sin_addr.s_addr) {
263 close(fd);
264 moan("rejecting connection from %s", inet_ntoa(sin.sin_addr));
265 return;
266 }
267 if (nonblockify(fd) || cloexec(fd)) {
268 close(fd);
269 moan("couldn't accept incoming connection: %s", strerror(errno));
270 return;
271 }
272 dofwd(fd, fd);
273 close(fd_s);
274 sel_rmfile(&cw.a);
275}
276
277static void dolisten(void)
278{
279 int fd;
280 int opt = 1;
281
282 if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0 ||
07212ba4 283 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) ||
ef4a1ab7 284 bind(fd, (struct sockaddr *)&cw.me, sizeof(cw.me)) ||
07212ba4 285 listen(fd, 1) || nonblockify(fd) || cloexec(fd))
286 die(1, "couldn't set up listening socket: %s", strerror(errno));
287 sel_initfile(&sel, &cw.a, fd, SEL_READ, doaccept, 0);
288 sel_addfile(&cw.a);
289}
290
291static void parseaddr(const char *pp, struct in_addr *a, unsigned short *pt)
292{
293 char *p = xstrdup(pp);
294 char *q = 0;
295 if (a && pt) {
296 strtok(p, ":");
297 q = strtok(0, "");
298 if (!q)
299 die(1, "missing port number in address `%s'", p);
300 } else if (pt) {
301 q = p;
302 }
303
304 if (a) {
305 struct hostent *h;
306 if ((h = gethostbyname(p)) == 0)
307 die(1, "unknown host `%s'", p);
308 memcpy(a, h->h_addr, sizeof(*a));
309 }
310
311 if (pt) {
312 struct servent *s;
313 char *qq;
314 unsigned long n;
315 if ((s = getservbyname(q, "tcp")) != 0)
316 *pt = s->s_port;
317 else if ((n = strtoul(q, &qq, 0)) == 0 || *qq || n > 0xffff)
318 die(1, "bad port number `%s'", q);
319 else
320 *pt = htons(n);
321 }
322}
323
324static void usage(FILE *fp)
325{
326 pquis(fp,
ef4a1ab7 327 "Usage: $ [-l PORT] [-b ADDR] [-p ADDR] [-c ADDR:PORT]\n\
328 ADDR:PORT ADDR:PORT\n");
07212ba4 329}
330
331static void version(FILE *fp)
332{
333 pquis(fp, "$, tripe version " VERSION "\n");
334}
335
336static void help(FILE *fp)
337{
338 version(fp);
339 fputc('\n', fp);
340 usage(fp);
341 fputs("\n\
342Options:\n\
343\n\
344-h, --help Display this help text.\n\
345-v, --version Display version number.\n\
346-u, --usage Display pointless usage message.\n\
347\n\
348-l, --listen=PORT Listen for connections to TCP PORT.\n\
ef4a1ab7 349-p, --peer=ADDR Only accept connections from IP ADDR.\n\
350-b, --bind=ADDR Bind to ADDR before connecting.\n\
07212ba4 351-c, --connect=ADDR:PORT Connect to IP ADDR, TCP PORT.\n\
352\n\
353Forwards UDP packets over a reliable stream. By default, uses stdin and\n\
354stdout; though it can use TCP sockets instead.\n\
355", fp);
356}
357
358int main(int argc, char *argv[])
359{
360 unsigned f = 0;
361 unsigned short pt;
ef4a1ab7 362 struct sockaddr_in connaddr, bindaddr;
07212ba4 363 struct sockaddr_in udp_me, udp_peer;
364 int len = 65536;
365
366#define f_bogus 1u
367
368 ego(argv[0]);
ef4a1ab7 369 bindaddr.sin_family = AF_INET;
370 bindaddr.sin_addr.s_addr = INADDR_ANY;
371 bindaddr.sin_port = 0;
07212ba4 372 connaddr.sin_family = AF_INET;
ef4a1ab7 373 connaddr.sin_addr.s_addr = INADDR_ANY;
07212ba4 374 cw.me.sin_family = AF_INET;
375 cw.me.sin_addr.s_addr = INADDR_ANY;
376 cw.me.sin_port = 0;
377 cw.peer.s_addr = INADDR_ANY;
378 sel_init(&sel);
379 for (;;) {
380 static struct option opt[] = {
381 { "help", 0, 0, 'h' },
382 { "version", 0, 0, 'v' },
383 { "usage", 0, 0, 'u' },
384 { "listen", OPTF_ARGREQ, 0, 'l' },
385 { "peer", OPTF_ARGREQ, 0, 'p' },
ef4a1ab7 386 { "bind", OPTF_ARGREQ, 0, 'b' },
07212ba4 387 { "connect", OPTF_ARGREQ, 0, 'c' },
388 { 0, 0, 0, 0 }
389 };
390 int i;
391
ef4a1ab7 392 i = mdwopt(argc, argv, "hvul:p:b:c:", opt, 0, 0, 0);
07212ba4 393 if (i < 0)
394 break;
395 switch (i) {
396 case 'h':
397 help(stdout);
398 exit(0);
399 case 'v':
400 version(stdout);
401 exit(0);
402 case 'u':
403 usage(stdout);
404 exit(0);
405 case 'l':
406 parseaddr(optarg, 0, &pt);
407 cw.me.sin_port = pt;
408 break;
409 case 'p':
410 parseaddr(optarg, &cw.peer, 0);
411 break;
ef4a1ab7 412 case 'b':
413 parseaddr(optarg, &bindaddr.sin_addr, 0);
414 break;
07212ba4 415 case 'c':
416 parseaddr(optarg, &connaddr.sin_addr, &pt);
417 connaddr.sin_port = pt;
418 break;
419 default:
420 f |= f_bogus;
421 break;
422 }
423 }
424 if (optind + 2 != argc || (f & f_bogus)) {
425 usage(stderr);
426 exit(1);
427 }
428
429 udp_me.sin_family = udp_peer.sin_family = AF_INET;
430 parseaddr(argv[optind], &udp_me.sin_addr, &pt);
431 udp_me.sin_port = pt;
432 parseaddr(argv[optind + 1], &udp_peer.sin_addr, &pt);
433 udp_peer.sin_port = pt;
434
435 if ((fd_udp = socket(PF_INET, SOCK_DGRAM, 0)) < 0 ||
436 bind(fd_udp, (struct sockaddr *)&udp_me, sizeof(udp_me)) ||
437 connect(fd_udp, (struct sockaddr *)&udp_peer, sizeof(udp_peer)) ||
438 setsockopt(fd_udp, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
439 setsockopt(fd_udp, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len)) ||
440 nonblockify(fd_udp) || cloexec(fd_udp))
441 die(1, "couldn't set up UDP socket: %s", strerror(errno));
442
443 if (cw.me.sin_port != 0)
444 dolisten();
445 else if (connaddr.sin_addr.s_addr != INADDR_ANY) {
446 int fd;
447 if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0 ||
ef4a1ab7 448 bind(fd, (struct sockaddr *)&bindaddr, sizeof(bindaddr)) ||
07212ba4 449 connect(fd, (struct sockaddr *)&connaddr, sizeof(connaddr)) ||
450 nonblockify(fd) || cloexec(fd))
451 die(1, "couldn't connect to TCP server: %s", strerror(errno));
452 dofwd(fd, fd);
453 } else
454 dofwd(STDIN_FILENO, STDOUT_FILENO);
455
456 for (;;)
457 sel_select(&sel);
458 return (0);
459}
460
461/*----- That's all, folks -------------------------------------------------*/