3 * $Id: pkstream.c,v 1.2 2003/11/29 23:49:32 mdw Exp $
5 * Forwarding UDP packets over a stream
7 * (c) 2003 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Trivial IP Encryption (TrIPE).
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.
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.
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.
29 /*----- Revision history --------------------------------------------------*
31 * $Log: pkstream.c,v $
32 * Revision 1.2 2003/11/29 23:49:32 mdw
35 * Revision 1.1 2003/04/23 12:53:28 mdw
36 * New pkstream program.
40 /*----- Header files ------------------------------------------------------*/
51 #include <sys/types.h>
55 #include <sys/socket.h>
56 #include <netinet/in.h>
57 #include <arpa/inet.h>
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>
68 #include <mLib/selpk.h>
70 /*----- Data structures ---------------------------------------------------*/
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 */
78 typedef 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 */
87 typedef 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 */
93 /*----- Static variables --------------------------------------------------*/
98 static size_t pk_nmax = 128, pk_szmax = 1024 * 1024;
100 /*----- Main code ---------------------------------------------------------*/
102 static int nonblockify(int fd)
104 return (fdflags(fd, O_NONBLOCK, O_NONBLOCK, 0, 0));
107 static int cloexec(int fd)
109 return (fdflags(fd, 0, 0, FD_CLOEXEC, FD_CLOEXEC));
112 static void dolisten(void);
114 static void doclose(pkstream *p)
118 close(p->p.reader.fd);
119 selpk_destroy(&p->p);
120 if (!(p->f & PKF_FULL))
124 for (pk = p->pks; pk; pk = ppk) {
130 if (cw.me.sin_port != 0)
136 static void rdtcp(octet *b, size_t sz, pkbuf *pk, size_t *k, void *vp)
146 if (pksz + 2 == sz) {
147 write(fd_udp, b + 2, pksz);
148 selpk_want(&p->p, 2);
150 selpk_want(&p->p, pksz + 2);
155 static void wrtcp(int fd, unsigned mode, void *vp)
158 struct iovec iov[NPK];
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;
169 if ((n = writev(fd, iov, i)) < 0) {
170 if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
172 moan("couldn't write to TCP socket: %s", strerror(errno));
178 for (pk = p->pks; n && pk; pk = ppk) {
193 p->pk_tail = &p->pks;
196 if ((p->f & PKF_FULL) && p->npk < pk_nmax && p->szpk < pk_szmax) {
202 static void rdudp(int fd, unsigned mode, void *vp)
209 if ((n = read(fd, buf, sizeof(buf))) < 0) {
210 if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
212 moan("couldn't read from UDP socket: %s", strerror(errno));
215 pk = xmalloc(sizeof(*pk));
217 pk->p = xmalloc(n + 2);
219 memcpy(pk->p + 2, buf, n);
223 p->pk_tail = &pk->next;
229 if (p->npk >= pk_nmax || p->szpk >= pk_szmax) {
235 static void dofwd(int fd_in, int fd_out)
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);
243 p->pk_tail = &p->pks;
244 p->npk = p->szpk = 0;
249 static void doaccept(int fd_s, unsigned mode, void *p)
252 struct sockaddr_in sin;
253 socklen_t sz = sizeof(sin);
255 if ((fd = accept(fd_s, (struct sockaddr *)&sin, &sz)) < 0) {
256 if (errno == EAGAIN || errno == EWOULDBLOCK || errno == EINTR)
258 moan("couldn't accept incoming connection: %s", strerror(errno));
261 if (cw.peer.s_addr != INADDR_ANY &&
262 cw.peer.s_addr != sin.sin_addr.s_addr) {
264 moan("rejecting connection from %s", inet_ntoa(sin.sin_addr));
267 if (nonblockify(fd) || cloexec(fd)) {
269 moan("couldn't accept incoming connection: %s", strerror(errno));
277 static void dolisten(void)
282 if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0 ||
283 setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt)) ||
284 bind(fd, (struct sockaddr *)&cw.me, sizeof(cw.me)) ||
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);
291 static void parseaddr(const char *pp, struct in_addr *a, unsigned short *pt)
293 char *p = xstrdup(pp);
299 die(1, "missing port number in address `%s'", p);
306 if ((h = gethostbyname(p)) == 0)
307 die(1, "unknown host `%s'", p);
308 memcpy(a, h->h_addr, sizeof(*a));
315 if ((s = getservbyname(q, "tcp")) != 0)
317 else if ((n = strtoul(q, &qq, 0)) == 0 || *qq || n > 0xffff)
318 die(1, "bad port number `%s'", q);
324 static void usage(FILE *fp)
327 "Usage: $ [-l PORT] [-b ADDR] [-p ADDR] [-c ADDR:PORT]\n\
328 ADDR:PORT ADDR:PORT\n");
331 static void version(FILE *fp)
333 pquis(fp, "$, tripe version " VERSION "\n");
336 static void help(FILE *fp)
344 -h, --help Display this help text.\n\
345 -v, --version Display version number.\n\
346 -u, --usage Display pointless usage message.\n\
348 -l, --listen=PORT Listen for connections to TCP PORT.\n\
349 -p, --peer=ADDR Only accept connections from IP ADDR.\n\
350 -b, --bind=ADDR Bind to ADDR before connecting.\n\
351 -c, --connect=ADDR:PORT Connect to IP ADDR, TCP PORT.\n\
353 Forwards UDP packets over a reliable stream. By default, uses stdin and\n\
354 stdout; though it can use TCP sockets instead.\n\
358 int main(int argc, char *argv[])
362 struct sockaddr_in connaddr, bindaddr;
363 struct sockaddr_in udp_me, udp_peer;
369 bindaddr.sin_family = AF_INET;
370 bindaddr.sin_addr.s_addr = INADDR_ANY;
371 bindaddr.sin_port = 0;
372 connaddr.sin_family = AF_INET;
373 connaddr.sin_addr.s_addr = INADDR_ANY;
374 cw.me.sin_family = AF_INET;
375 cw.me.sin_addr.s_addr = INADDR_ANY;
377 cw.peer.s_addr = INADDR_ANY;
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' },
386 { "bind", OPTF_ARGREQ, 0, 'b' },
387 { "connect", OPTF_ARGREQ, 0, 'c' },
392 i = mdwopt(argc, argv, "hvul:p:b:c:", opt, 0, 0, 0);
406 parseaddr(optarg, 0, &pt);
410 parseaddr(optarg, &cw.peer, 0);
413 parseaddr(optarg, &bindaddr.sin_addr, 0);
416 parseaddr(optarg, &connaddr.sin_addr, &pt);
417 connaddr.sin_port = pt;
424 if (optind + 2 != argc || (f & f_bogus)) {
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;
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));
443 if (cw.me.sin_port != 0)
445 else if (connaddr.sin_addr.s_addr != INADDR_ANY) {
447 if ((fd = socket(PF_INET, SOCK_STREAM, 0)) < 0 ||
448 bind(fd, (struct sockaddr *)&bindaddr, sizeof(bindaddr)) ||
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));
454 dofwd(STDIN_FILENO, STDOUT_FILENO);
461 /*----- That's all, folks -------------------------------------------------*/