chiark / gitweb /
doc/.gitignore: Make the patterns more general.
[tripe] / pkstream / pkstream.c
CommitLineData
07212ba4 1/* -*-c-*-
2 *
07212ba4 3 * Forwarding UDP packets over a stream
4 *
5 * (c) 2003 Straylight/Edgeware
6 */
7
e04c2d50 8/*----- Licensing notice --------------------------------------------------*
07212ba4 9 *
10 * This file is part of Trivial IP Encryption (TrIPE).
11 *
12 * TrIPE is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
e04c2d50 16 *
07212ba4 17 * TrIPE is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
e04c2d50 21 *
07212ba4 22 * You should have received a copy of the GNU General Public License
23 * along with TrIPE; if not, write to the Free Software Foundation,
24 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 */
26
07212ba4 27/*----- Header files ------------------------------------------------------*/
28
29#include "config.h"
30
31#include <ctype.h>
32#include <errno.h>
33#include <stdio.h>
34#include <stdlib.h>
35#include <string.h>
36
37#include <sys/time.h>
38#include <sys/types.h>
39#include <unistd.h>
40#include <fcntl.h>
41#include <sys/uio.h>
42#include <sys/socket.h>
43#include <netinet/in.h>
44#include <arpa/inet.h>
45#include <netdb.h>
46
47#include <mLib/alloc.h>
48#include <mLib/bits.h>
49#include <mLib/dstr.h>
50#include <mLib/fdflags.h>
51#include <mLib/mdwopt.h>
52#include <mLib/quis.h>
53#include <mLib/report.h>
54#include <mLib/sel.h>
55#include <mLib/selpk.h>
56
23df0e5b
MW
57#include "util.h"
58
07212ba4 59/*----- Data structures ---------------------------------------------------*/
60
61typedef struct pk {
62 struct pk *next; /* Next packet in the chain */
63 octet *p, *o; /* Buffer start and current posn */
64 size_t n; /* Size of packet remaining */
65} pk;
66
67typedef struct pkstream {
68 unsigned f; /* Flags... */
69#define PKF_FULL 1u /* Buffer is full: stop reading */
70 sel_file r, w; /* Read and write selectors */
71 pk *pks, **pk_tail; /* Packet queue */
72 size_t npk, szpk; /* Number and size of data */
73 selpk p; /* Packet parser */
74} pkstream;
75
76typedef struct connwait {
77 sel_file a; /* Selector */
78 struct sockaddr_in me; /* Who I'm meant to be */
79 struct in_addr peer; /* Who my peer is */
80} connwait;
81
82/*----- Static variables --------------------------------------------------*/
83
84static sel_state sel;
85static connwait cw;
86static int fd_udp;
87static size_t pk_nmax = 128, pk_szmax = 1024 * 1024;
88
89/*----- Main code ---------------------------------------------------------*/
90
91static int nonblockify(int fd)
f98df549 92 { return (fdflags(fd, O_NONBLOCK, O_NONBLOCK, 0, 0)); }
07212ba4 93
94static int cloexec(int fd)
f98df549 95 { return (fdflags(fd, 0, 0, FD_CLOEXEC, FD_CLOEXEC)); }
07212ba4 96
97static void dolisten(void);
98
99static void doclose(pkstream *p)
100{
101 pk *pk, *ppk;
102 close(p->w.fd);
103 close(p->p.reader.fd);
104 selpk_destroy(&p->p);
105 if (!(p->f & PKF_FULL))
106 sel_rmfile(&p->r);
107 if (p->npk)
108 sel_rmfile(&p->w);
109 for (pk = p->pks; pk; pk = ppk) {
110 ppk = pk->next;
111 xfree(pk->p);
112 xfree(pk);
113 }
114 xfree(p);
115 if (cw.me.sin_port != 0)
116 dolisten();
117 else
118 exit(0);
119}
120
121static void rdtcp(octet *b, size_t sz, pkbuf *pk, size_t *k, void *vp)
122{
123 pkstream *p = vp;
124 size_t pksz;
125
126 if (!sz) {
127 doclose(p);
128 return;
129 }
130 pksz = LOAD16(b);
131 if (pksz + 2 == sz) {
99735357 132 DISCARD(write(fd_udp, b + 2, pksz));
07212ba4 133 selpk_want(&p->p, 2);
134 } else {
135 selpk_want(&p->p, pksz + 2);
136 *k = sz;
137 }
138}
139
140static void wrtcp(int fd, unsigned mode, void *vp)
141{
142#define NPK 16
143 struct iovec iov[NPK];
144 pkstream *p = vp;
145 size_t i;
146 ssize_t n;
147 pk *pk, *ppk;
148
149 for (i = 0, pk = p->pks; i < NPK && pk; i++, pk = pk->next) {
150 iov[i].iov_base = pk->o;
151 iov[i].iov_len = pk->n;
152 }
153
154 if ((n = writev(fd, iov, i)) < 0) {
155 if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
156 return;
157 moan("couldn't write to TCP socket: %s", strerror(errno));
158 doclose(p);
159 return;
160 }
161
162 p->szpk -= n;
163 for (pk = p->pks; n && pk; pk = ppk) {
164 ppk = pk->next;
165 if (pk->n <= n) {
166 p->npk--;
167 n -= pk->n;
168 xfree(pk->p);
169 xfree(pk);
170 } else {
171 pk->n -= n;
172 pk->o += n;
173 break;
174 }
175 }
176 p->pks = pk;
177 if (!pk) {
178 p->pk_tail = &p->pks;
179 sel_rmfile(&p->w);
180 }
181 if ((p->f & PKF_FULL) && p->npk < pk_nmax && p->szpk < pk_szmax) {
182 p->f &= ~PKF_FULL;
183 sel_addfile(&p->r);
184 }
185}
186
187static void rdudp(int fd, unsigned mode, void *vp)
188{
189 octet buf[65536];
190 ssize_t n;
191 pkstream *p = vp;
192 pk *pk;
193
194 if ((n = read(fd, buf, sizeof(buf))) < 0) {
195 if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
196 return;
197 moan("couldn't read from UDP socket: %s", strerror(errno));
198 return;
199 }
200 pk = xmalloc(sizeof(*pk));
201 pk->next = 0;
202 pk->p = xmalloc(n + 2);
203 STORE16(pk->p, n);
204 memcpy(pk->p + 2, buf, n);
205 pk->o = pk->p;
206 pk->n = n + 2;
207 *p->pk_tail = pk;
208 p->pk_tail = &pk->next;
209 if (!p->npk)
210 sel_addfile(&p->w);
211 sel_force(&p->w);
212 p->npk++;
213 p->szpk += n + 2;
214 if (p->npk >= pk_nmax || p->szpk >= pk_szmax) {
215 sel_rmfile(&p->r);
216 p->f |= PKF_FULL;
217 }
218}
219
220static void dofwd(int fd_in, int fd_out)
221{
222 pkstream *p = xmalloc(sizeof(*p));
223 sel_initfile(&sel, &p->r, fd_udp, SEL_READ, rdudp, p);
224 sel_initfile(&sel, &p->w, fd_out, SEL_WRITE, wrtcp, p);
225 selpk_init(&p->p, &sel, fd_in, rdtcp, p);
226 selpk_want(&p->p, 2);
227 p->pks = 0;
228 p->pk_tail = &p->pks;
229 p->npk = p->szpk = 0;
230 p->f = 0;
231 sel_addfile(&p->r);
232}
233
234static void doaccept(int fd_s, unsigned mode, void *p)
235{
236 int fd;
237 struct sockaddr_in sin;
238 socklen_t sz = sizeof(sin);
239
240 if ((fd = accept(fd_s, (struct sockaddr *)&sin, &sz)) < 0) {
241 if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
242 return;
243 moan("couldn't accept incoming connection: %s", strerror(errno));
244 return;
245 }
246 if (cw.peer.s_addr != INADDR_ANY &&
247 cw.peer.s_addr != sin.sin_addr.s_addr) {
248 close(fd);
249 moan("rejecting connection from %s", inet_ntoa(sin.sin_addr));
250 return;
251 }
252 if (nonblockify(fd) || cloexec(fd)) {
253 close(fd);
254 moan("couldn't accept incoming connection: %s", strerror(errno));
255 return;
256 }
257 dofwd(fd, fd);
258 close(fd_s);
259 sel_rmfile(&cw.a);
260}
261
262static void dolisten(void)
263{
264 int fd;
265 int opt = 1;
266
267 if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0 ||
07212ba4 268 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) ||
ef4a1ab7 269 bind(fd, (struct sockaddr *)&cw.me, sizeof(cw.me)) ||
07212ba4 270 listen(fd, 1) || nonblockify(fd) || cloexec(fd))
271 die(1, "couldn't set up listening socket: %s", strerror(errno));
272 sel_initfile(&sel, &cw.a, fd, SEL_READ, doaccept, 0);
273 sel_addfile(&cw.a);
274}
275
276static void parseaddr(const char *pp, struct in_addr *a, unsigned short *pt)
277{
278 char *p = xstrdup(pp);
279 char *q = 0;
280 if (a && pt) {
281 strtok(p, ":");
282 q = strtok(0, "");
283 if (!q)
284 die(1, "missing port number in address `%s'", p);
285 } else if (pt) {
286 q = p;
287 }
288
289 if (a) {
290 struct hostent *h;
291 if ((h = gethostbyname(p)) == 0)
292 die(1, "unknown host `%s'", p);
293 memcpy(a, h->h_addr, sizeof(*a));
294 }
295
296 if (pt) {
297 struct servent *s;
298 char *qq;
299 unsigned long n;
300 if ((s = getservbyname(q, "tcp")) != 0)
301 *pt = s->s_port;
302 else if ((n = strtoul(q, &qq, 0)) == 0 || *qq || n > 0xffff)
303 die(1, "bad port number `%s'", q);
304 else
305 *pt = htons(n);
306 }
307}
308
309static void usage(FILE *fp)
310{
311 pquis(fp,
ef4a1ab7 312 "Usage: $ [-l PORT] [-b ADDR] [-p ADDR] [-c ADDR:PORT]\n\
313 ADDR:PORT ADDR:PORT\n");
07212ba4 314}
315
316static void version(FILE *fp)
f98df549 317 { pquis(fp, "$, tripe version " VERSION "\n"); }
07212ba4 318
319static void help(FILE *fp)
320{
321 version(fp);
322 fputc('\n', fp);
323 usage(fp);
324 fputs("\n\
325Options:\n\
326\n\
327-h, --help Display this help text.\n\
328-v, --version Display version number.\n\
329-u, --usage Display pointless usage message.\n\
330\n\
331-l, --listen=PORT Listen for connections to TCP PORT.\n\
ef4a1ab7 332-p, --peer=ADDR Only accept connections from IP ADDR.\n\
333-b, --bind=ADDR Bind to ADDR before connecting.\n\
07212ba4 334-c, --connect=ADDR:PORT Connect to IP ADDR, TCP PORT.\n\
335\n\
336Forwards UDP packets over a reliable stream. By default, uses stdin and\n\
337stdout; though it can use TCP sockets instead.\n\
338", fp);
339}
340
341int main(int argc, char *argv[])
342{
343 unsigned f = 0;
344 unsigned short pt;
ef4a1ab7 345 struct sockaddr_in connaddr, bindaddr;
07212ba4 346 struct sockaddr_in udp_me, udp_peer;
347 int len = 65536;
348
349#define f_bogus 1u
350
351 ego(argv[0]);
ef4a1ab7 352 bindaddr.sin_family = AF_INET;
353 bindaddr.sin_addr.s_addr = INADDR_ANY;
354 bindaddr.sin_port = 0;
07212ba4 355 connaddr.sin_family = AF_INET;
ef4a1ab7 356 connaddr.sin_addr.s_addr = INADDR_ANY;
07212ba4 357 cw.me.sin_family = AF_INET;
358 cw.me.sin_addr.s_addr = INADDR_ANY;
359 cw.me.sin_port = 0;
360 cw.peer.s_addr = INADDR_ANY;
361 sel_init(&sel);
362 for (;;) {
363 static struct option opt[] = {
364 { "help", 0, 0, 'h' },
365 { "version", 0, 0, 'v' },
366 { "usage", 0, 0, 'u' },
367 { "listen", OPTF_ARGREQ, 0, 'l' },
368 { "peer", OPTF_ARGREQ, 0, 'p' },
ef4a1ab7 369 { "bind", OPTF_ARGREQ, 0, 'b' },
07212ba4 370 { "connect", OPTF_ARGREQ, 0, 'c' },
371 { 0, 0, 0, 0 }
372 };
373 int i;
374
ef4a1ab7 375 i = mdwopt(argc, argv, "hvul:p:b:c:", opt, 0, 0, 0);
07212ba4 376 if (i < 0)
377 break;
378 switch (i) {
379 case 'h':
380 help(stdout);
381 exit(0);
382 case 'v':
383 version(stdout);
384 exit(0);
385 case 'u':
386 usage(stdout);
387 exit(0);
388 case 'l':
389 parseaddr(optarg, 0, &pt);
390 cw.me.sin_port = pt;
391 break;
392 case 'p':
393 parseaddr(optarg, &cw.peer, 0);
394 break;
ef4a1ab7 395 case 'b':
396 parseaddr(optarg, &bindaddr.sin_addr, 0);
30678daa 397 cw.me.sin_addr = bindaddr.sin_addr;
ef4a1ab7 398 break;
07212ba4 399 case 'c':
400 parseaddr(optarg, &connaddr.sin_addr, &pt);
401 connaddr.sin_port = pt;
402 break;
403 default:
404 f |= f_bogus;
405 break;
406 }
407 }
408 if (optind + 2 != argc || (f & f_bogus)) {
409 usage(stderr);
410 exit(1);
411 }
412
413 udp_me.sin_family = udp_peer.sin_family = AF_INET;
414 parseaddr(argv[optind], &udp_me.sin_addr, &pt);
e04c2d50 415 udp_me.sin_port = pt;
07212ba4 416 parseaddr(argv[optind + 1], &udp_peer.sin_addr, &pt);
417 udp_peer.sin_port = pt;
418
419 if ((fd_udp = socket(PF_INET, SOCK_DGRAM, 0)) < 0 ||
420 bind(fd_udp, (struct sockaddr *)&udp_me, sizeof(udp_me)) ||
421 connect(fd_udp, (struct sockaddr *)&udp_peer, sizeof(udp_peer)) ||
422 setsockopt(fd_udp, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
423 setsockopt(fd_udp, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len)) ||
424 nonblockify(fd_udp) || cloexec(fd_udp))
425 die(1, "couldn't set up UDP socket: %s", strerror(errno));
426
427 if (cw.me.sin_port != 0)
428 dolisten();
429 else if (connaddr.sin_addr.s_addr != INADDR_ANY) {
430 int fd;
431 if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0 ||
ef4a1ab7 432 bind(fd, (struct sockaddr *)&bindaddr, sizeof(bindaddr)) ||
07212ba4 433 connect(fd, (struct sockaddr *)&connaddr, sizeof(connaddr)) ||
434 nonblockify(fd) || cloexec(fd))
435 die(1, "couldn't connect to TCP server: %s", strerror(errno));
436 dofwd(fd, fd);
437 } else
438 dofwd(STDIN_FILENO, STDOUT_FILENO);
439
440 for (;;)
441 sel_select(&sel);
442 return (0);
443}
444
445/*----- That's all, folks -------------------------------------------------*/