Commit | Line | Data |
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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 | * | |
11ad66c2 MW |
12 | * TrIPE is free software: you can redistribute it and/or modify it under |
13 | * the terms of the GNU General Public License as published by the Free | |
14 | * Software Foundation; either version 3 of the License, or (at your | |
15 | * option) any later version. | |
e04c2d50 | 16 | * |
11ad66c2 MW |
17 | * TrIPE is distributed in the hope that it will be useful, but WITHOUT |
18 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
19 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
20 | * for more details. | |
e04c2d50 | 21 | * |
07212ba4 | 22 | * You should have received a copy of the GNU General Public License |
11ad66c2 | 23 | * along with TrIPE. If not, see <https://www.gnu.org/licenses/>. |
07212ba4 | 24 | */ |
25 | ||
07212ba4 | 26 | /*----- Header files ------------------------------------------------------*/ |
27 | ||
28 | #include "config.h" | |
29 | ||
30 | #include <ctype.h> | |
31 | #include <errno.h> | |
32 | #include <stdio.h> | |
33 | #include <stdlib.h> | |
34 | #include <string.h> | |
35 | ||
36 | #include <sys/time.h> | |
37 | #include <sys/types.h> | |
38 | #include <unistd.h> | |
39 | #include <fcntl.h> | |
40 | #include <sys/uio.h> | |
41 | #include <sys/socket.h> | |
42 | #include <netinet/in.h> | |
43 | #include <arpa/inet.h> | |
44 | #include <netdb.h> | |
45 | ||
46 | #include <mLib/alloc.h> | |
47 | #include <mLib/bits.h> | |
48 | #include <mLib/dstr.h> | |
49 | #include <mLib/fdflags.h> | |
50 | #include <mLib/mdwopt.h> | |
51 | #include <mLib/quis.h> | |
52 | #include <mLib/report.h> | |
53 | #include <mLib/sel.h> | |
54 | #include <mLib/selpk.h> | |
55 | ||
23df0e5b MW |
56 | #include "util.h" |
57 | ||
07212ba4 | 58 | /*----- Data structures ---------------------------------------------------*/ |
59 | ||
60 | typedef struct pk { | |
61 | struct pk *next; /* Next packet in the chain */ | |
62 | octet *p, *o; /* Buffer start and current posn */ | |
63 | size_t n; /* Size of packet remaining */ | |
64 | } pk; | |
65 | ||
66 | typedef struct pkstream { | |
67 | unsigned f; /* Flags... */ | |
68 | #define PKF_FULL 1u /* Buffer is full: stop reading */ | |
69 | sel_file r, w; /* Read and write selectors */ | |
70 | pk *pks, **pk_tail; /* Packet queue */ | |
71 | size_t npk, szpk; /* Number and size of data */ | |
72 | selpk p; /* Packet parser */ | |
73 | } pkstream; | |
74 | ||
75 | typedef struct connwait { | |
76 | sel_file a; /* Selector */ | |
77 | struct sockaddr_in me; /* Who I'm meant to be */ | |
78 | struct in_addr peer; /* Who my peer is */ | |
79 | } connwait; | |
80 | ||
81 | /*----- Static variables --------------------------------------------------*/ | |
82 | ||
83 | static sel_state sel; | |
84 | static connwait cw; | |
85 | static int fd_udp; | |
86 | static size_t pk_nmax = 128, pk_szmax = 1024 * 1024; | |
87 | ||
88 | /*----- Main code ---------------------------------------------------------*/ | |
89 | ||
90 | static int nonblockify(int fd) | |
f98df549 | 91 | { return (fdflags(fd, O_NONBLOCK, O_NONBLOCK, 0, 0)); } |
07212ba4 | 92 | |
93 | static int cloexec(int fd) | |
f98df549 | 94 | { return (fdflags(fd, 0, 0, FD_CLOEXEC, FD_CLOEXEC)); } |
07212ba4 | 95 | |
96 | static void dolisten(void); | |
97 | ||
98 | static void doclose(pkstream *p) | |
99 | { | |
100 | pk *pk, *ppk; | |
101 | close(p->w.fd); | |
102 | close(p->p.reader.fd); | |
103 | selpk_destroy(&p->p); | |
104 | if (!(p->f & PKF_FULL)) | |
105 | sel_rmfile(&p->r); | |
106 | if (p->npk) | |
107 | sel_rmfile(&p->w); | |
108 | for (pk = p->pks; pk; pk = ppk) { | |
109 | ppk = pk->next; | |
110 | xfree(pk->p); | |
111 | xfree(pk); | |
112 | } | |
113 | xfree(p); | |
114 | if (cw.me.sin_port != 0) | |
115 | dolisten(); | |
116 | else | |
117 | exit(0); | |
118 | } | |
119 | ||
120 | static void rdtcp(octet *b, size_t sz, pkbuf *pk, size_t *k, void *vp) | |
121 | { | |
122 | pkstream *p = vp; | |
123 | size_t pksz; | |
124 | ||
125 | if (!sz) { | |
126 | doclose(p); | |
127 | return; | |
128 | } | |
129 | pksz = LOAD16(b); | |
130 | if (pksz + 2 == sz) { | |
99735357 | 131 | DISCARD(write(fd_udp, b + 2, pksz)); |
07212ba4 | 132 | selpk_want(&p->p, 2); |
133 | } else { | |
134 | selpk_want(&p->p, pksz + 2); | |
135 | *k = sz; | |
136 | } | |
137 | } | |
138 | ||
139 | static void wrtcp(int fd, unsigned mode, void *vp) | |
140 | { | |
141 | #define NPK 16 | |
142 | struct iovec iov[NPK]; | |
143 | pkstream *p = vp; | |
144 | size_t i; | |
145 | ssize_t n; | |
146 | pk *pk, *ppk; | |
147 | ||
148 | for (i = 0, pk = p->pks; i < NPK && pk; i++, pk = pk->next) { | |
149 | iov[i].iov_base = pk->o; | |
150 | iov[i].iov_len = pk->n; | |
151 | } | |
152 | ||
153 | if ((n = writev(fd, iov, i)) < 0) { | |
154 | if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR) | |
155 | return; | |
156 | moan("couldn't write to TCP socket: %s", strerror(errno)); | |
157 | doclose(p); | |
158 | return; | |
159 | } | |
160 | ||
161 | p->szpk -= n; | |
162 | for (pk = p->pks; n && pk; pk = ppk) { | |
163 | ppk = pk->next; | |
164 | if (pk->n <= n) { | |
165 | p->npk--; | |
166 | n -= pk->n; | |
167 | xfree(pk->p); | |
168 | xfree(pk); | |
169 | } else { | |
170 | pk->n -= n; | |
171 | pk->o += n; | |
172 | break; | |
173 | } | |
174 | } | |
175 | p->pks = pk; | |
176 | if (!pk) { | |
177 | p->pk_tail = &p->pks; | |
178 | sel_rmfile(&p->w); | |
179 | } | |
180 | if ((p->f & PKF_FULL) && p->npk < pk_nmax && p->szpk < pk_szmax) { | |
181 | p->f &= ~PKF_FULL; | |
182 | sel_addfile(&p->r); | |
183 | } | |
184 | } | |
185 | ||
186 | static void rdudp(int fd, unsigned mode, void *vp) | |
187 | { | |
188 | octet buf[65536]; | |
189 | ssize_t n; | |
190 | pkstream *p = vp; | |
191 | pk *pk; | |
192 | ||
193 | if ((n = read(fd, buf, sizeof(buf))) < 0) { | |
194 | if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR) | |
195 | return; | |
196 | moan("couldn't read from UDP socket: %s", strerror(errno)); | |
197 | return; | |
198 | } | |
199 | pk = xmalloc(sizeof(*pk)); | |
200 | pk->next = 0; | |
201 | pk->p = xmalloc(n + 2); | |
202 | STORE16(pk->p, n); | |
203 | memcpy(pk->p + 2, buf, n); | |
204 | pk->o = pk->p; | |
205 | pk->n = n + 2; | |
206 | *p->pk_tail = pk; | |
207 | p->pk_tail = &pk->next; | |
208 | if (!p->npk) | |
209 | sel_addfile(&p->w); | |
210 | sel_force(&p->w); | |
211 | p->npk++; | |
212 | p->szpk += n + 2; | |
213 | if (p->npk >= pk_nmax || p->szpk >= pk_szmax) { | |
214 | sel_rmfile(&p->r); | |
215 | p->f |= PKF_FULL; | |
216 | } | |
217 | } | |
218 | ||
219 | static void dofwd(int fd_in, int fd_out) | |
220 | { | |
221 | pkstream *p = xmalloc(sizeof(*p)); | |
222 | sel_initfile(&sel, &p->r, fd_udp, SEL_READ, rdudp, p); | |
223 | sel_initfile(&sel, &p->w, fd_out, SEL_WRITE, wrtcp, p); | |
224 | selpk_init(&p->p, &sel, fd_in, rdtcp, p); | |
225 | selpk_want(&p->p, 2); | |
226 | p->pks = 0; | |
227 | p->pk_tail = &p->pks; | |
228 | p->npk = p->szpk = 0; | |
229 | p->f = 0; | |
230 | sel_addfile(&p->r); | |
231 | } | |
232 | ||
233 | static void doaccept(int fd_s, unsigned mode, void *p) | |
234 | { | |
235 | int fd; | |
236 | struct sockaddr_in sin; | |
237 | socklen_t sz = sizeof(sin); | |
238 | ||
239 | if ((fd = accept(fd_s, (struct sockaddr *)&sin, &sz)) < 0) { | |
240 | if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR) | |
241 | return; | |
242 | moan("couldn't accept incoming connection: %s", strerror(errno)); | |
243 | return; | |
244 | } | |
245 | if (cw.peer.s_addr != INADDR_ANY && | |
246 | cw.peer.s_addr != sin.sin_addr.s_addr) { | |
247 | close(fd); | |
248 | moan("rejecting connection from %s", inet_ntoa(sin.sin_addr)); | |
249 | return; | |
250 | } | |
251 | if (nonblockify(fd) || cloexec(fd)) { | |
252 | close(fd); | |
253 | moan("couldn't accept incoming connection: %s", strerror(errno)); | |
254 | return; | |
255 | } | |
256 | dofwd(fd, fd); | |
257 | close(fd_s); | |
258 | sel_rmfile(&cw.a); | |
259 | } | |
260 | ||
261 | static void dolisten(void) | |
262 | { | |
263 | int fd; | |
264 | int opt = 1; | |
265 | ||
266 | if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0 || | |
07212ba4 | 267 | setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) || |
ef4a1ab7 | 268 | bind(fd, (struct sockaddr *)&cw.me, sizeof(cw.me)) || |
07212ba4 | 269 | listen(fd, 1) || nonblockify(fd) || cloexec(fd)) |
270 | die(1, "couldn't set up listening socket: %s", strerror(errno)); | |
271 | sel_initfile(&sel, &cw.a, fd, SEL_READ, doaccept, 0); | |
272 | sel_addfile(&cw.a); | |
273 | } | |
274 | ||
275 | static void parseaddr(const char *pp, struct in_addr *a, unsigned short *pt) | |
276 | { | |
277 | char *p = xstrdup(pp); | |
278 | char *q = 0; | |
279 | if (a && pt) { | |
280 | strtok(p, ":"); | |
281 | q = strtok(0, ""); | |
282 | if (!q) | |
283 | die(1, "missing port number in address `%s'", p); | |
284 | } else if (pt) { | |
285 | q = p; | |
286 | } | |
287 | ||
288 | if (a) { | |
289 | struct hostent *h; | |
290 | if ((h = gethostbyname(p)) == 0) | |
291 | die(1, "unknown host `%s'", p); | |
292 | memcpy(a, h->h_addr, sizeof(*a)); | |
293 | } | |
294 | ||
295 | if (pt) { | |
296 | struct servent *s; | |
297 | char *qq; | |
298 | unsigned long n; | |
299 | if ((s = getservbyname(q, "tcp")) != 0) | |
300 | *pt = s->s_port; | |
301 | else if ((n = strtoul(q, &qq, 0)) == 0 || *qq || n > 0xffff) | |
302 | die(1, "bad port number `%s'", q); | |
303 | else | |
304 | *pt = htons(n); | |
305 | } | |
306 | } | |
307 | ||
308 | static void usage(FILE *fp) | |
309 | { | |
310 | pquis(fp, | |
ef4a1ab7 | 311 | "Usage: $ [-l PORT] [-b ADDR] [-p ADDR] [-c ADDR:PORT]\n\ |
312 | ADDR:PORT ADDR:PORT\n"); | |
07212ba4 | 313 | } |
314 | ||
315 | static void version(FILE *fp) | |
f98df549 | 316 | { pquis(fp, "$, tripe version " VERSION "\n"); } |
07212ba4 | 317 | |
318 | static void help(FILE *fp) | |
319 | { | |
320 | version(fp); | |
321 | fputc('\n', fp); | |
322 | usage(fp); | |
323 | fputs("\n\ | |
324 | Options:\n\ | |
325 | \n\ | |
326 | -h, --help Display this help text.\n\ | |
327 | -v, --version Display version number.\n\ | |
328 | -u, --usage Display pointless usage message.\n\ | |
329 | \n\ | |
330 | -l, --listen=PORT Listen for connections to TCP PORT.\n\ | |
ef4a1ab7 | 331 | -p, --peer=ADDR Only accept connections from IP ADDR.\n\ |
332 | -b, --bind=ADDR Bind to ADDR before connecting.\n\ | |
07212ba4 | 333 | -c, --connect=ADDR:PORT Connect to IP ADDR, TCP PORT.\n\ |
334 | \n\ | |
335 | Forwards UDP packets over a reliable stream. By default, uses stdin and\n\ | |
336 | stdout; though it can use TCP sockets instead.\n\ | |
337 | ", fp); | |
338 | } | |
339 | ||
340 | int main(int argc, char *argv[]) | |
341 | { | |
342 | unsigned f = 0; | |
343 | unsigned short pt; | |
ef4a1ab7 | 344 | struct sockaddr_in connaddr, bindaddr; |
07212ba4 | 345 | struct sockaddr_in udp_me, udp_peer; |
346 | int len = 65536; | |
347 | ||
348 | #define f_bogus 1u | |
349 | ||
350 | ego(argv[0]); | |
ef4a1ab7 | 351 | bindaddr.sin_family = AF_INET; |
352 | bindaddr.sin_addr.s_addr = INADDR_ANY; | |
353 | bindaddr.sin_port = 0; | |
07212ba4 | 354 | connaddr.sin_family = AF_INET; |
ef4a1ab7 | 355 | connaddr.sin_addr.s_addr = INADDR_ANY; |
07212ba4 | 356 | cw.me.sin_family = AF_INET; |
357 | cw.me.sin_addr.s_addr = INADDR_ANY; | |
358 | cw.me.sin_port = 0; | |
359 | cw.peer.s_addr = INADDR_ANY; | |
360 | sel_init(&sel); | |
361 | for (;;) { | |
362 | static struct option opt[] = { | |
363 | { "help", 0, 0, 'h' }, | |
364 | { "version", 0, 0, 'v' }, | |
365 | { "usage", 0, 0, 'u' }, | |
366 | { "listen", OPTF_ARGREQ, 0, 'l' }, | |
367 | { "peer", OPTF_ARGREQ, 0, 'p' }, | |
ef4a1ab7 | 368 | { "bind", OPTF_ARGREQ, 0, 'b' }, |
07212ba4 | 369 | { "connect", OPTF_ARGREQ, 0, 'c' }, |
370 | { 0, 0, 0, 0 } | |
371 | }; | |
372 | int i; | |
373 | ||
ef4a1ab7 | 374 | i = mdwopt(argc, argv, "hvul:p:b:c:", opt, 0, 0, 0); |
07212ba4 | 375 | if (i < 0) |
376 | break; | |
377 | switch (i) { | |
378 | case 'h': | |
379 | help(stdout); | |
380 | exit(0); | |
381 | case 'v': | |
382 | version(stdout); | |
383 | exit(0); | |
384 | case 'u': | |
385 | usage(stdout); | |
386 | exit(0); | |
387 | case 'l': | |
388 | parseaddr(optarg, 0, &pt); | |
389 | cw.me.sin_port = pt; | |
390 | break; | |
391 | case 'p': | |
392 | parseaddr(optarg, &cw.peer, 0); | |
393 | break; | |
ef4a1ab7 | 394 | case 'b': |
395 | parseaddr(optarg, &bindaddr.sin_addr, 0); | |
30678daa | 396 | cw.me.sin_addr = bindaddr.sin_addr; |
ef4a1ab7 | 397 | break; |
07212ba4 | 398 | case 'c': |
399 | parseaddr(optarg, &connaddr.sin_addr, &pt); | |
400 | connaddr.sin_port = pt; | |
401 | break; | |
402 | default: | |
403 | f |= f_bogus; | |
404 | break; | |
405 | } | |
406 | } | |
407 | if (optind + 2 != argc || (f & f_bogus)) { | |
408 | usage(stderr); | |
409 | exit(1); | |
410 | } | |
411 | ||
412 | udp_me.sin_family = udp_peer.sin_family = AF_INET; | |
413 | parseaddr(argv[optind], &udp_me.sin_addr, &pt); | |
e04c2d50 | 414 | udp_me.sin_port = pt; |
07212ba4 | 415 | parseaddr(argv[optind + 1], &udp_peer.sin_addr, &pt); |
416 | udp_peer.sin_port = pt; | |
417 | ||
418 | if ((fd_udp = socket(PF_INET, SOCK_DGRAM, 0)) < 0 || | |
419 | bind(fd_udp, (struct sockaddr *)&udp_me, sizeof(udp_me)) || | |
420 | connect(fd_udp, (struct sockaddr *)&udp_peer, sizeof(udp_peer)) || | |
421 | setsockopt(fd_udp, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) || | |
422 | setsockopt(fd_udp, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len)) || | |
423 | nonblockify(fd_udp) || cloexec(fd_udp)) | |
424 | die(1, "couldn't set up UDP socket: %s", strerror(errno)); | |
425 | ||
426 | if (cw.me.sin_port != 0) | |
427 | dolisten(); | |
428 | else if (connaddr.sin_addr.s_addr != INADDR_ANY) { | |
429 | int fd; | |
430 | if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0 || | |
ef4a1ab7 | 431 | bind(fd, (struct sockaddr *)&bindaddr, sizeof(bindaddr)) || |
07212ba4 | 432 | connect(fd, (struct sockaddr *)&connaddr, sizeof(connaddr)) || |
433 | nonblockify(fd) || cloexec(fd)) | |
434 | die(1, "couldn't connect to TCP server: %s", strerror(errno)); | |
435 | dofwd(fd, fd); | |
436 | } else | |
437 | dofwd(STDIN_FILENO, STDOUT_FILENO); | |
438 | ||
c14225f6 MW |
439 | for (;;) { |
440 | if (sel_select(&sel) && errno != EINTR) | |
441 | die(1, "select failed: %s", strerror(errno)); | |
442 | } | |
07212ba4 | 443 | return (0); |
444 | } | |
445 | ||
446 | /*----- That's all, folks -------------------------------------------------*/ |