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