Commit | Line | Data |
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f6b4ffdc MW |
1 | /* -*-c-*- |
2 | * | |
3 | * Freeze a file system under remote control | |
4 | * | |
5 | * (c) 2012 Mark Wooding | |
6 | */ | |
7 | ||
8 | /*----- Licensing notice --------------------------------------------------* | |
9 | * | |
10 | * This file is part of the `rsync-backup' program. | |
11 | * | |
12 | * rsync-backup 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. | |
16 | * | |
17 | * rsync-backup 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. | |
21 | * | |
22 | * You should have received a copy of the GNU General Public License along | |
23 | * with rsync-backup; if not, write to the Free Software Foundation, | |
24 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
25 | */ | |
26 | ||
27 | /*----- Header files ------------------------------------------------------*/ | |
28 | ||
29 | #include <assert.h> | |
30 | #include <errno.h> | |
31 | #include <limits.h> | |
32 | #include <signal.h> | |
33 | #include <stdarg.h> | |
34 | #include <stdio.h> | |
35 | #include <string.h> | |
36 | #include <stdlib.h> | |
37 | #include <time.h> | |
38 | ||
39 | #include <sys/types.h> | |
40 | #include <sys/time.h> | |
41 | #include <sys/select.h> | |
42 | #include <unistd.h> | |
43 | #include <fcntl.h> | |
44 | #include <sys/ioctl.h> | |
45 | ||
46 | #include <linux/fs.h> | |
47 | ||
48 | #include <sys/socket.h> | |
49 | #include <arpa/inet.h> | |
50 | #include <netinet/in.h> | |
51 | #include <netdb.h> | |
52 | ||
53 | #include <mLib/alloc.h> | |
54 | #include <mLib/dstr.h> | |
55 | #include <mLib/base64.h> | |
56 | #include <mLib/fdflags.h> | |
57 | #include <mLib/mdwopt.h> | |
58 | #include <mLib/quis.h> | |
59 | #include <mLib/report.h> | |
60 | #include <mLib/sub.h> | |
61 | #include <mLib/tv.h> | |
62 | ||
63 | /*----- Magic constants ---------------------------------------------------*/ | |
64 | ||
65 | #define COOKIESZ 16 /* Size of authentication cookie */ | |
66 | #define TO_CONNECT 30 /* Timeout for incoming connection */ | |
67 | #define TO_KEEPALIVE 60 /* Timeout between keepalives */ | |
68 | ||
69 | /*----- Utility functions -------------------------------------------------*/ | |
70 | ||
71 | static int getuint(const char *p, const char *q) | |
72 | { | |
73 | unsigned long i; | |
74 | int e = errno; | |
75 | char *qq; | |
76 | ||
77 | if (!q) q = p + strlen(p); | |
78 | errno = 0; | |
79 | i = strtoul(p, &qq, 0); | |
80 | if (errno || qq < q || i > INT_MAX) | |
81 | die(1, "invalid integer `%s'", p); | |
82 | errno = e; | |
83 | return ((int)i); | |
84 | } | |
85 | ||
86 | #ifdef DEBUG | |
87 | # define D(x) x | |
88 | #else | |
89 | # define D(x) | |
90 | #endif | |
91 | ||
92 | /*----- Token management --------------------------------------------------*/ | |
93 | ||
94 | struct token { | |
95 | const char *label; | |
96 | char tok[(COOKIESZ + 2)*4/3 + 1]; | |
97 | }; | |
98 | ||
99 | #define TOKENS(_) \ | |
100 | _(FREEZE) \ | |
101 | _(FROZEN) \ | |
102 | _(KEEPALIVE) \ | |
103 | _(THAW) \ | |
104 | _(THAWED) | |
105 | ||
106 | enum { | |
107 | #define ENUM(tok) T_##tok, | |
108 | TOKENS(ENUM) | |
109 | #undef ENUM | |
110 | T_LIMIT | |
111 | }; | |
112 | ||
113 | enum { | |
114 | #define MASK(tok) TF_##tok = 1u << T_##tok, | |
115 | TOKENS(MASK) | |
116 | #undef ENUM | |
117 | TF_ALL = (1u << T_LIMIT) - 1u | |
118 | }; | |
119 | ||
120 | static struct token toktab[] = { | |
121 | #define INIT(tok) { #tok }, | |
122 | TOKENS(INIT) | |
123 | #undef INIT | |
124 | { 0 } | |
125 | }; | |
126 | ||
127 | static void inittoks(void) | |
128 | { | |
129 | static struct token *t, *tt; | |
130 | unsigned char buf[COOKIESZ]; | |
131 | int fd; | |
132 | ssize_t n; | |
133 | base64_ctx bc; | |
134 | dstr d = DSTR_INIT; | |
135 | ||
136 | if ((fd = open("/dev/urandom", O_RDONLY)) < 0) | |
137 | die(2, "open (urandom): %s", strerror(errno)); | |
138 | ||
139 | for (t = toktab; t->label; t++) { | |
140 | again: | |
141 | n = read(fd, buf, COOKIESZ); | |
142 | if (n < 0) die(2, "read (urandom): %s", strerror(errno)); | |
143 | else if (n < COOKIESZ) die(2, "read (urandom): short read"); | |
144 | base64_init(&bc); | |
145 | base64_encode(&bc, buf, COOKIESZ, &d); | |
146 | base64_encode(&bc, 0, 0, &d); | |
147 | dstr_putz(&d); | |
148 | ||
149 | for (tt = toktab; tt < t; tt++) { | |
150 | if (strcmp(d.buf, tt->tok) == 0) | |
151 | goto again; | |
152 | } | |
153 | ||
154 | assert(d.len < sizeof(t->tok)); | |
155 | memcpy(t->tok, d.buf, d.len + 1); | |
156 | dstr_reset(&d); | |
157 | } | |
158 | } | |
159 | ||
160 | struct tokmatch { | |
161 | unsigned tf; /* Possible token matches */ | |
162 | size_t o; /* Offset into token string */ | |
163 | unsigned f; /* Flags */ | |
164 | #define TMF_CR 1u /* Seen trailing carriage-return */ | |
165 | }; | |
166 | ||
167 | static void tokmatch_init(struct tokmatch *tm) | |
168 | { tm->tf = TF_ALL; tm->o = 0; tm->f = 0; } | |
169 | ||
170 | static int tokmatch_update(struct tokmatch *tm, int ch) | |
171 | { | |
172 | const struct token *t; | |
173 | unsigned tf; | |
174 | ||
175 | switch (ch) { | |
176 | case '\n': | |
177 | for (t = toktab, tf = 1; t->label; t++, tf <<= 1) { | |
178 | if ((tm->tf & tf) && !t->tok[tm->o]) | |
179 | return (tf); | |
180 | } | |
181 | return (-1); | |
182 | case '\r': | |
183 | for (t = toktab, tf = 1; t->label; t++, tf <<= 1) { | |
184 | if ((tm->tf & tf) && !t->tok[tm->o] && !(tm->f & TMF_CR)) | |
185 | tm->f |= TMF_CR; | |
186 | else | |
187 | tm->tf &= ~tf; | |
188 | } | |
189 | break; | |
190 | default: | |
191 | for (t = toktab, tf = 1; t->label; t++, tf <<= 1) { | |
192 | if ((tm->tf & tf) && ch != t->tok[tm->o]) | |
193 | tm->tf &= ~tf; | |
194 | } | |
195 | tm->o++; | |
196 | break; | |
197 | } | |
198 | return (0); | |
199 | } | |
200 | ||
201 | static int writetok(unsigned i, int fd) | |
202 | { | |
203 | static const char nl = '\n'; | |
204 | const struct token *t = &toktab[i]; | |
205 | size_t n = strlen(t->tok); | |
206 | ||
207 | errno = EIO; | |
208 | if (write(fd, t->tok, n) < n || | |
209 | write(fd, &nl, 1) < 1) | |
210 | return (-1); | |
211 | return (0); | |
212 | } | |
213 | ||
214 | /*----- Data structures ---------------------------------------------------*/ | |
215 | ||
216 | struct client { | |
217 | struct client *next; /* Links in the client chain */ | |
218 | int fd; /* File descriptor for socket */ | |
219 | struct tokmatch tm; /* Token matching context */ | |
220 | }; | |
221 | ||
222 | /*----- Static variables --------------------------------------------------*/ | |
223 | ||
224 | static int *fs; /* File descriptors for targets */ | |
225 | static char **fsname; /* File system names */ | |
226 | static size_t nfs; /* Number of descriptors */ | |
227 | ||
228 | /*----- Cleanup -----------------------------------------------------------*/ | |
229 | ||
230 | #define EOM ((char *)0) | |
231 | static void emerg(const char *msg,...) | |
232 | { | |
233 | va_list ap; | |
234 | ||
235 | #define MSG(m) \ | |
236 | do { const char *m_ = m; if (write(2, m_, strlen(m_))); } while (0) | |
237 | ||
238 | va_start(ap, msg); | |
239 | MSG(QUIS); MSG(": "); | |
240 | do { | |
241 | MSG(msg); | |
242 | msg = va_arg(ap, const char *); | |
243 | } while (msg != EOM); | |
244 | MSG("\n"); | |
245 | ||
246 | #undef MSG | |
247 | } | |
248 | ||
249 | static void partial_cleanup(size_t n) | |
250 | { | |
251 | int i; | |
252 | int bad = 0; | |
253 | ||
254 | for (i = 0; i < nfs; i++) { | |
255 | if (fs[i] == -1) | |
256 | emerg("not really thawing ", fsname[i], EOM); | |
257 | else if (fs[i] != -2) { | |
258 | if (ioctl(fs[i], FITHAW, 0)) { | |
259 | emerg("VERY BAD! failed to thaw ", | |
260 | fsname[i], ": ", strerror(errno), EOM); | |
261 | bad = 1; | |
262 | } | |
263 | close(fs[i]); | |
264 | } | |
265 | fs[i] = -2; | |
266 | } | |
267 | if (bad) _exit(112); | |
268 | } | |
269 | ||
270 | static void cleanup(void) { partial_cleanup(nfs); } | |
271 | ||
272 | static int sigcatch[] = { | |
273 | SIGINT, SIGQUIT, SIGTERM, SIGHUP, SIGALRM, | |
274 | SIGILL, SIGSEGV, SIGBUS, SIGFPE, SIGABRT | |
275 | }; | |
276 | ||
277 | static void sigmumble(int sig) | |
278 | { | |
279 | sigset_t ss; | |
280 | ||
281 | cleanup(); | |
282 | emerg(strsignal(sig), 0); | |
283 | ||
284 | signal(sig, SIG_DFL); | |
285 | sigemptyset(&ss); sigaddset(&ss, sig); | |
286 | sigprocmask(SIG_UNBLOCK, &ss, 0); | |
287 | raise(sig); | |
288 | _exit(4); | |
289 | } | |
290 | ||
291 | /*----- Help functions ----------------------------------------------------*/ | |
292 | ||
293 | static void version(FILE *fp) | |
294 | { pquis(fp, "$, " PACKAGE " version " VERSION "\n"); } | |
295 | static void usage(FILE *fp) | |
296 | { pquis(fp, "Usage: $ [-n] [-a ADDR] [-p LOPORT[-HIPORT]] FILSYS ...\n"); } | |
297 | ||
298 | static void help(FILE *fp) | |
299 | { | |
300 | version(fp); putc('\n', fp); | |
301 | usage(fp); | |
302 | fputs("\n\ | |
303 | Freezes a filesystem temporarily, with some measure of safety.\n\ | |
304 | \n\ | |
305 | The program listens for connections on a TCP port, and prints a line\n\ | |
306 | \n\ | |
307 | PORT COOKIE\n\ | |
308 | \n\ | |
309 | to standard output. You must connect to this PORT and send the COOKIE\n\ | |
310 | followed by a newline within a short period of time. The filesystems\n\ | |
311 | will then be frozen, and `OK' written to the connection. In order to\n\ | |
312 | keep the file system frozen, you must keep the connection open, and\n\ | |
313 | feed data into it. If the connection closes, or no data is received\n\ | |
314 | within a set period of time, or the program receives one of a variety\n\ | |
315 | of signals or otherwise becomes unhappy, the filesystems are thawed again.\n\ | |
316 | \n\ | |
317 | Options:\n\ | |
318 | \n\ | |
319 | -h, --help Print this help text.\n\ | |
320 | -v, --version Print the program version number.\n\ | |
321 | -u, --usage Print a short usage message.\n\ | |
322 | \n\ | |
323 | -a, --address=ADDR Listen only on ADDR.\n\ | |
324 | -n, --not-really Don't really freeze or thaw filesystems.\n\ | |
325 | -p, --port-range=LO[-HI] Select a port number between LO and HI.\n\ | |
326 | If HI is omitted, choose only LO.\n\ | |
327 | ", fp); | |
328 | } | |
329 | ||
330 | /*----- Main program ------------------------------------------------------*/ | |
331 | ||
332 | int main(int argc, char *argv[]) | |
333 | { | |
334 | char buf[256]; | |
335 | int loport = -1, hiport = -1; | |
336 | int sk, fd, maxfd; | |
337 | struct sockaddr_in sin; | |
338 | socklen_t sasz; | |
339 | struct hostent *h; | |
340 | const char *p, *q; | |
341 | struct timeval now, when, delta; | |
342 | struct client *clients = 0, *c, **cc; | |
343 | const struct token *t; | |
344 | struct tokmatch tm; | |
345 | fd_set fdin; | |
346 | int i; | |
347 | ssize_t n; | |
348 | unsigned f = 0; | |
349 | #define f_bogus 0x01u | |
350 | #define f_notreally 0x02u | |
351 | ||
352 | ego(argv[0]); | |
353 | sub_init(); | |
354 | ||
355 | /* --- Partially initialize the socket address --- */ | |
356 | ||
357 | sin.sin_family = AF_INET; | |
358 | sin.sin_addr.s_addr = INADDR_ANY; | |
359 | sin.sin_port = 0; | |
360 | ||
361 | /* --- Parse the command line --- */ | |
362 | ||
363 | for (;;) { | |
364 | static struct option opts[] = { | |
365 | { "help", 0, 0, 'h' }, | |
366 | { "version", 0, 0, 'v' }, | |
367 | { "usage", 0, 0, 'u' }, | |
368 | { "address", OPTF_ARGREQ, 0, 'a' }, | |
369 | { "not-really", 0, 0, 'n' }, | |
370 | { "port-range", OPTF_ARGREQ, 0, 'p' }, | |
371 | { 0, 0, 0, 0 } | |
372 | }; | |
373 | ||
374 | if ((i = mdwopt(argc, argv, "hvua:np:", opts, 0, 0, 0)) < 0) break; | |
375 | switch (i) { | |
376 | case 'h': help(stdout); exit(0); | |
377 | case 'v': version(stdout); exit(0); | |
378 | case 'u': usage(stdout); exit(0); | |
379 | case 'a': | |
380 | if ((h = gethostbyname(optarg)) == 0) { | |
381 | die(1, "failed to resolve address `%s': %s", | |
382 | optarg, hstrerror(h_errno)); | |
383 | } | |
384 | if (h->h_addrtype != AF_INET) | |
385 | die(1, "unexpected address type resolving `%s'", optarg); | |
386 | assert(h->h_length == sizeof(sin.sin_addr)); | |
387 | memcpy(&sin.sin_addr, h->h_addr, sizeof(sin.sin_addr)); | |
388 | break; | |
389 | case 'n': f |= f_notreally; break; | |
390 | case 'p': | |
391 | if ((p = strchr(optarg, '-')) == 0) | |
392 | loport = hiport = getuint(optarg, 0); | |
393 | else { | |
394 | loport = getuint(optarg, p); | |
395 | hiport = getuint(p + 1, 0); | |
396 | } | |
397 | break; | |
398 | default: f |= f_bogus; break; | |
399 | } | |
400 | } | |
401 | if (f & f_bogus) { usage(stderr); exit(1); } | |
402 | if (optind >= argc) { usage(stderr); exit(1); } | |
403 | ||
404 | /* --- Open the file systems --- */ | |
405 | ||
406 | nfs = argc - optind; | |
407 | fsname = &argv[optind]; | |
408 | fs = xmalloc(nfs*sizeof(*fs)); | |
409 | for (i = 0; i < nfs; i++) { | |
410 | if ((fs[i] = open(fsname[i], O_RDONLY)) < 0) | |
411 | die(2, "open (%s): %s", fsname[i], strerror(errno)); | |
412 | } | |
413 | ||
414 | if (f & f_notreally) { | |
415 | for (i = 0; i < nfs; i++) { | |
416 | close(fs[i]); | |
417 | fs[i] = -1; | |
418 | } | |
419 | } | |
420 | ||
421 | /* --- Generate random tokens --- */ | |
422 | ||
423 | inittoks(); | |
424 | ||
425 | /* --- Create the listening socket --- */ | |
426 | ||
427 | if ((sk = socket(PF_INET, SOCK_STREAM, 0)) < 0) | |
428 | die(2, "socket: %s", strerror(errno)); | |
429 | i = 1; | |
430 | if (setsockopt(sk, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i))) | |
431 | die(2, "setsockopt (reuseaddr): %s", strerror(errno)); | |
432 | if (fdflags(sk, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC)) | |
433 | die(2, "fdflags: %s", strerror(errno)); | |
434 | if (loport < 0 || loport == hiport) { | |
435 | if (loport >= 0) sin.sin_port = htons(loport); | |
436 | if (bind(sk, (struct sockaddr *)&sin, sizeof(sin))) | |
437 | die(2, "bind: %s", strerror(errno)); | |
438 | } else if (hiport != loport) { | |
439 | for (i = loport; i <= hiport; i++) { | |
440 | sin.sin_port = htons(i); | |
441 | if (bind(sk, (struct sockaddr *)&sin, sizeof(sin)) >= 0) break; | |
442 | else if (errno != EADDRINUSE) | |
443 | die(2, "bind: %s", strerror(errno)); | |
444 | } | |
445 | if (i > hiport) die(2, "bind: all ports in use"); | |
446 | } | |
447 | if (listen(sk, 5)) die(2, "listen: %s", strerror(errno)); | |
448 | ||
449 | /* --- Tell the caller how to connect to us, and start the timer --- */ | |
450 | ||
451 | sasz = sizeof(sin); | |
452 | if (getsockname(sk, (struct sockaddr *)&sin, &sasz)) | |
453 | die(2, "getsockname (listen): %s", strerror(errno)); | |
454 | printf("PORT %d\n", ntohs(sin.sin_port)); | |
455 | for (t = toktab; t->label; t++) | |
456 | printf("TOKEN %s %s\n", t->label, t->tok); | |
457 | printf("READY\n"); | |
458 | if (fflush(stdout) || ferror(stdout)) | |
459 | die(2, "write (stdout, rubric): %s", strerror(errno)); | |
460 | gettimeofday(&now, 0); TV_ADDL(&when, &now, TO_CONNECT, 0); | |
461 | ||
462 | /* --- Collect incoming connections, and check for the cookie --- * | |
463 | * | |
464 | * This is the tricky part. | |
465 | */ | |
466 | ||
467 | for (;;) { | |
468 | FD_ZERO(&fdin); | |
469 | FD_SET(sk, &fdin); | |
470 | maxfd = sk; | |
471 | for (c = clients; c; c = c->next) { | |
472 | FD_SET(c->fd, &fdin); | |
473 | if (c->fd > maxfd) maxfd = c->fd; | |
474 | } | |
475 | TV_SUB(&delta, &when, &now); | |
476 | if (select(maxfd + 1, &fdin, 0, 0, &delta) < 0) | |
477 | die(2, "select (accept): %s", strerror(errno)); | |
478 | gettimeofday(&now, 0); | |
479 | ||
480 | if (TV_CMP(&now, >=, &when)) die(3, "timeout (accept)"); | |
481 | ||
482 | if (FD_ISSET(sk, &fdin)) { | |
483 | sasz = sizeof(sin); | |
484 | fd = accept(sk, (struct sockaddr *)&sin, &sasz); | |
485 | if (fd >= 0) { | |
486 | if (fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC) < 0) | |
487 | die(2, "fdflags: %s", strerror(errno)); | |
488 | c = CREATE(struct client); | |
489 | c->next = clients; c->fd = fd; tokmatch_init(&c->tm); | |
490 | clients = c; | |
491 | } | |
492 | #ifdef DEBUG | |
493 | else if (errno != EAGAIN) | |
494 | moan("accept: %s", strerror(errno)); | |
495 | #endif | |
496 | } | |
497 | ||
498 | for (cc = &clients; *cc;) { | |
499 | c = *cc; | |
500 | if (!FD_ISSET(c->fd, &fdin)) goto next_client; | |
501 | n = read(c->fd, buf, sizeof(buf)); | |
502 | if (!n) goto disconn; | |
503 | else if (n < 0) { | |
504 | if (errno == EAGAIN) goto next_client; | |
505 | D( moan("read (client; auth): %s", strerror(errno)); ) | |
506 | goto disconn; | |
507 | } else { | |
508 | for (p = buf, q = p + n; p < q; p++) { | |
509 | switch (tokmatch_update(&c->tm, *p)) { | |
510 | case 0: break; | |
511 | case TF_FREEZE: goto connected; | |
512 | default: | |
513 | D( moan("bad token from client"); ) | |
514 | goto disconn; | |
515 | } | |
516 | } | |
517 | } | |
518 | ||
519 | next_client: | |
520 | cc = &c->next; | |
521 | continue; | |
522 | ||
523 | disconn: | |
524 | close(c->fd); | |
525 | *cc = c->next; | |
526 | DESTROY(c); | |
527 | continue; | |
528 | } | |
529 | } | |
530 | ||
531 | connected: | |
532 | close(sk); sk = c->fd; | |
533 | while (clients) { | |
534 | if (clients->fd != sk) close(clients->fd); | |
535 | c = clients->next; | |
536 | DESTROY(clients); | |
537 | clients = c; | |
538 | } | |
539 | ||
540 | /* --- Establish signal handlers --- * | |
541 | * | |
542 | * Hopefully this will prevent bad things happening if we have an accident. | |
543 | */ | |
544 | ||
545 | for (i = 0; i < sizeof(sigcatch)/sizeof(sigcatch[0]); i++) { | |
546 | if (signal(sigcatch[i], sigmumble) == SIG_ERR) | |
547 | die(2, "signal (%d): %s", i, strerror(errno)); | |
548 | } | |
549 | atexit(cleanup); | |
550 | ||
551 | /* --- Prevent the OOM killer from clobbering us --- */ | |
552 | ||
553 | if ((fd = open("/proc/self/oom_adj", O_WRONLY)) < 0 || | |
554 | write(fd, "-17\n", 4) < 4 || | |
555 | close(fd)) | |
556 | die(2, "set oom_adj: %s", strerror(errno)); | |
557 | ||
558 | /* --- Actually freeze the filesystem --- */ | |
559 | ||
560 | for (i = 0; i < nfs; i++) { | |
561 | if (fs[i] == -1) | |
562 | moan("not really freezing %s", fsname[i]); | |
563 | else { | |
564 | if (ioctl(fs[i], FIFREEZE, 0) < 0) { | |
565 | partial_cleanup(i); | |
566 | die(2, "ioctl (freeze %s): %s", fsname[i], strerror(errno)); | |
567 | } | |
568 | } | |
569 | } | |
570 | if (writetok(T_FROZEN, sk)) { | |
571 | cleanup(); | |
572 | die(2, "write (frozen): %s", strerror(errno)); | |
573 | } | |
574 | ||
575 | /* --- Now wait for the other end to detach --- */ | |
576 | ||
577 | tokmatch_init(&tm); | |
578 | TV_ADDL(&when, &now, TO_KEEPALIVE, 0); | |
579 | for (p++; p < q; p++) { | |
580 | switch (tokmatch_update(&tm, *p)) { | |
581 | case 0: break; | |
582 | case TF_KEEPALIVE: tokmatch_init(&tm); break; | |
583 | case TF_THAW: goto done; | |
584 | default: cleanup(); die(3, "unknown token (keepalive)"); | |
585 | } | |
586 | } | |
587 | for (;;) { | |
588 | FD_ZERO(&fdin); | |
589 | FD_SET(sk, &fdin); | |
590 | TV_SUB(&delta, &when, &now); | |
591 | if (select(sk + 1, &fdin, 0, 0, &delta) < 0) { | |
592 | cleanup(); | |
593 | die(2, "select (keepalive): %s", strerror(errno)); | |
594 | } | |
595 | ||
596 | gettimeofday(&now, 0); | |
597 | if (TV_CMP(&now, >, &when)) { | |
598 | cleanup(); die(3, "timeout (keepalive)"); | |
599 | } | |
600 | if (FD_ISSET(sk, &fdin)) { | |
601 | n = read(sk, buf, sizeof(buf)); | |
602 | if (!n) { cleanup(); die(3, "end-of-file (keepalive)"); } | |
603 | else if (n < 0) { | |
604 | if (errno == EAGAIN) ; | |
605 | else { | |
606 | cleanup(); | |
607 | die(2, "read (client, keepalive): %s", strerror(errno)); | |
608 | } | |
609 | } else { | |
610 | for (p = buf, q = p + n; p < q; p++) { | |
611 | switch (tokmatch_update(&tm, *p)) { | |
612 | case 0: break; | |
613 | case TF_KEEPALIVE: | |
614 | TV_ADDL(&when, &now, TO_KEEPALIVE, 0); | |
615 | tokmatch_init(&tm); | |
616 | break; | |
617 | case TF_THAW: | |
618 | goto done; | |
619 | default: | |
620 | cleanup(); | |
621 | die(3, "unknown token (keepalive)"); | |
622 | } | |
623 | } | |
624 | } | |
625 | } | |
626 | } | |
627 | ||
628 | done: | |
629 | cleanup(); | |
630 | if (writetok(T_THAWED, sk)) | |
631 | die(2, "write (thaw): %s", strerror(errno)); | |
632 | close(sk); | |
633 | return (0); | |
634 | } | |
635 | ||
636 | /*----- That's all, folks -------------------------------------------------*/ |