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> | |
ff6237ea | 57 | #include <mLib/macros.h> |
f6b4ffdc MW |
58 | #include <mLib/mdwopt.h> |
59 | #include <mLib/quis.h> | |
60 | #include <mLib/report.h> | |
61 | #include <mLib/sub.h> | |
62 | #include <mLib/tv.h> | |
63 | ||
64 | /*----- Magic constants ---------------------------------------------------*/ | |
65 | ||
66 | #define COOKIESZ 16 /* Size of authentication cookie */ | |
67 | #define TO_CONNECT 30 /* Timeout for incoming connection */ | |
68 | #define TO_KEEPALIVE 60 /* Timeout between keepalives */ | |
69 | ||
70 | /*----- Utility functions -------------------------------------------------*/ | |
71 | ||
72 | static int getuint(const char *p, const char *q) | |
73 | { | |
74 | unsigned long i; | |
75 | int e = errno; | |
76 | char *qq; | |
77 | ||
78 | if (!q) q = p + strlen(p); | |
79 | errno = 0; | |
80 | i = strtoul(p, &qq, 0); | |
81 | if (errno || qq < q || i > INT_MAX) | |
82 | die(1, "invalid integer `%s'", p); | |
83 | errno = e; | |
84 | return ((int)i); | |
85 | } | |
86 | ||
87 | #ifdef DEBUG | |
88 | # define D(x) x | |
89 | #else | |
90 | # define D(x) | |
91 | #endif | |
92 | ||
93 | /*----- Token management --------------------------------------------------*/ | |
94 | ||
95 | struct token { | |
96 | const char *label; | |
97 | char tok[(COOKIESZ + 2)*4/3 + 1]; | |
98 | }; | |
99 | ||
100 | #define TOKENS(_) \ | |
101 | _(FREEZE) \ | |
102 | _(FROZEN) \ | |
103 | _(KEEPALIVE) \ | |
104 | _(THAW) \ | |
105 | _(THAWED) | |
106 | ||
107 | enum { | |
108 | #define ENUM(tok) T_##tok, | |
109 | TOKENS(ENUM) | |
110 | #undef ENUM | |
111 | T_LIMIT | |
112 | }; | |
113 | ||
114 | enum { | |
115 | #define MASK(tok) TF_##tok = 1u << T_##tok, | |
116 | TOKENS(MASK) | |
117 | #undef ENUM | |
118 | TF_ALL = (1u << T_LIMIT) - 1u | |
119 | }; | |
120 | ||
121 | static struct token toktab[] = { | |
122 | #define INIT(tok) { #tok }, | |
123 | TOKENS(INIT) | |
124 | #undef INIT | |
125 | { 0 } | |
126 | }; | |
127 | ||
128 | static void inittoks(void) | |
129 | { | |
130 | static struct token *t, *tt; | |
131 | unsigned char buf[COOKIESZ]; | |
132 | int fd; | |
133 | ssize_t n; | |
134 | base64_ctx bc; | |
135 | dstr d = DSTR_INIT; | |
136 | ||
137 | if ((fd = open("/dev/urandom", O_RDONLY)) < 0) | |
138 | die(2, "open (urandom): %s", strerror(errno)); | |
139 | ||
140 | for (t = toktab; t->label; t++) { | |
141 | again: | |
142 | n = read(fd, buf, COOKIESZ); | |
143 | if (n < 0) die(2, "read (urandom): %s", strerror(errno)); | |
144 | else if (n < COOKIESZ) die(2, "read (urandom): short read"); | |
145 | base64_init(&bc); | |
146 | base64_encode(&bc, buf, COOKIESZ, &d); | |
147 | base64_encode(&bc, 0, 0, &d); | |
148 | dstr_putz(&d); | |
149 | ||
150 | for (tt = toktab; tt < t; tt++) { | |
151 | if (strcmp(d.buf, tt->tok) == 0) | |
152 | goto again; | |
153 | } | |
154 | ||
155 | assert(d.len < sizeof(t->tok)); | |
156 | memcpy(t->tok, d.buf, d.len + 1); | |
157 | dstr_reset(&d); | |
158 | } | |
159 | } | |
160 | ||
161 | struct tokmatch { | |
162 | unsigned tf; /* Possible token matches */ | |
163 | size_t o; /* Offset into token string */ | |
164 | unsigned f; /* Flags */ | |
165 | #define TMF_CR 1u /* Seen trailing carriage-return */ | |
166 | }; | |
167 | ||
168 | static void tokmatch_init(struct tokmatch *tm) | |
169 | { tm->tf = TF_ALL; tm->o = 0; tm->f = 0; } | |
170 | ||
171 | static int tokmatch_update(struct tokmatch *tm, int ch) | |
172 | { | |
173 | const struct token *t; | |
174 | unsigned tf; | |
175 | ||
176 | switch (ch) { | |
177 | case '\n': | |
178 | for (t = toktab, tf = 1; t->label; t++, tf <<= 1) { | |
179 | if ((tm->tf & tf) && !t->tok[tm->o]) | |
180 | return (tf); | |
181 | } | |
182 | return (-1); | |
183 | case '\r': | |
184 | for (t = toktab, tf = 1; t->label; t++, tf <<= 1) { | |
185 | if ((tm->tf & tf) && !t->tok[tm->o] && !(tm->f & TMF_CR)) | |
186 | tm->f |= TMF_CR; | |
187 | else | |
188 | tm->tf &= ~tf; | |
189 | } | |
190 | break; | |
191 | default: | |
192 | for (t = toktab, tf = 1; t->label; t++, tf <<= 1) { | |
193 | if ((tm->tf & tf) && ch != t->tok[tm->o]) | |
194 | tm->tf &= ~tf; | |
195 | } | |
196 | tm->o++; | |
197 | break; | |
198 | } | |
199 | return (0); | |
200 | } | |
201 | ||
202 | static int writetok(unsigned i, int fd) | |
203 | { | |
204 | static const char nl = '\n'; | |
205 | const struct token *t = &toktab[i]; | |
206 | size_t n = strlen(t->tok); | |
207 | ||
208 | errno = EIO; | |
209 | if (write(fd, t->tok, n) < n || | |
210 | write(fd, &nl, 1) < 1) | |
211 | return (-1); | |
212 | return (0); | |
213 | } | |
214 | ||
215 | /*----- Data structures ---------------------------------------------------*/ | |
216 | ||
217 | struct client { | |
218 | struct client *next; /* Links in the client chain */ | |
219 | int fd; /* File descriptor for socket */ | |
220 | struct tokmatch tm; /* Token matching context */ | |
221 | }; | |
222 | ||
223 | /*----- Static variables --------------------------------------------------*/ | |
224 | ||
225 | static int *fs; /* File descriptors for targets */ | |
226 | static char **fsname; /* File system names */ | |
227 | static size_t nfs; /* Number of descriptors */ | |
228 | ||
229 | /*----- Cleanup -----------------------------------------------------------*/ | |
230 | ||
231 | #define EOM ((char *)0) | |
ff6237ea | 232 | static void EXECL_LIKE(0) emerg(const char *msg,...) |
f6b4ffdc MW |
233 | { |
234 | va_list ap; | |
235 | ||
236 | #define MSG(m) \ | |
237 | do { const char *m_ = m; if (write(2, m_, strlen(m_))); } while (0) | |
238 | ||
239 | va_start(ap, msg); | |
240 | MSG(QUIS); MSG(": "); | |
241 | do { | |
242 | MSG(msg); | |
243 | msg = va_arg(ap, const char *); | |
244 | } while (msg != EOM); | |
245 | MSG("\n"); | |
246 | ||
247 | #undef MSG | |
248 | } | |
249 | ||
250 | static void partial_cleanup(size_t n) | |
251 | { | |
252 | int i; | |
253 | int bad = 0; | |
254 | ||
255 | for (i = 0; i < nfs; i++) { | |
256 | if (fs[i] == -1) | |
257 | emerg("not really thawing ", fsname[i], EOM); | |
258 | else if (fs[i] != -2) { | |
259 | if (ioctl(fs[i], FITHAW, 0)) { | |
260 | emerg("VERY BAD! failed to thaw ", | |
261 | fsname[i], ": ", strerror(errno), EOM); | |
262 | bad = 1; | |
263 | } | |
264 | close(fs[i]); | |
265 | } | |
266 | fs[i] = -2; | |
267 | } | |
268 | if (bad) _exit(112); | |
269 | } | |
270 | ||
271 | static void cleanup(void) { partial_cleanup(nfs); } | |
272 | ||
273 | static int sigcatch[] = { | |
274 | SIGINT, SIGQUIT, SIGTERM, SIGHUP, SIGALRM, | |
275 | SIGILL, SIGSEGV, SIGBUS, SIGFPE, SIGABRT | |
276 | }; | |
277 | ||
ff6237ea | 278 | static void NORETURN sigmumble(int sig) |
f6b4ffdc MW |
279 | { |
280 | sigset_t ss; | |
281 | ||
282 | cleanup(); | |
ff6237ea | 283 | emerg(strsignal(sig), EOM); |
f6b4ffdc MW |
284 | |
285 | signal(sig, SIG_DFL); | |
286 | sigemptyset(&ss); sigaddset(&ss, sig); | |
287 | sigprocmask(SIG_UNBLOCK, &ss, 0); | |
288 | raise(sig); | |
289 | _exit(4); | |
290 | } | |
291 | ||
292 | /*----- Help functions ----------------------------------------------------*/ | |
293 | ||
294 | static void version(FILE *fp) | |
295 | { pquis(fp, "$, " PACKAGE " version " VERSION "\n"); } | |
296 | static void usage(FILE *fp) | |
297 | { pquis(fp, "Usage: $ [-n] [-a ADDR] [-p LOPORT[-HIPORT]] FILSYS ...\n"); } | |
298 | ||
299 | static void help(FILE *fp) | |
300 | { | |
301 | version(fp); putc('\n', fp); | |
302 | usage(fp); | |
303 | fputs("\n\ | |
304 | Freezes a filesystem temporarily, with some measure of safety.\n\ | |
305 | \n\ | |
6952bdd6 MW |
306 | The program listens for connections on a TCP port, and prints a number of\n\ |
307 | lines:\n\ | |
f6b4ffdc | 308 | \n\ |
6952bdd6 MW |
309 | PORT <port>\n\ |
310 | TOKEN FREEZE <token>\n\ | |
311 | TOKEN FROZEN <token>\n\ | |
312 | TOKEN KEEPALIVE <token>\n\ | |
313 | TOKEN THAW <token>\n\ | |
314 | TOKEN THAWED <token>\n\ | |
315 | READY\n\ | |
f6b4ffdc | 316 | \n\ |
6952bdd6 MW |
317 | to standard output. You must connect to the <port>, using TCP, and send\n\ |
318 | the FREEZE token followed by a newline within a short period of time. The\n\ | |
319 | filesystems will then be frozen, and the FROZEN token written to the\n\ | |
320 | connection. In order to keep the file system frozen, you must keep the\n\ | |
321 | connection open, and periodically echo the KEEPALIVE token to it. To\n\ | |
322 | release the filesystems, write the THAW token to the connection, followed\n\ | |
323 | by a newline; the filesystem will be thawed, and the THAWED token echoed\n\ | |
324 | back. If the connection closes, or no valid message is received within a\n\ | |
325 | set period of time, or the program receives one of a variety of signals or\n\ | |
326 | otherwise becomes unhappy, the filesystems are thawed again.\n\ | |
327 | \n\ | |
328 | The program exits with status zero if everything worked as planned, while\n\ | |
329 | nonzero codes indicate failures of various kinds (see the manual); an exit\n\ | |
330 | status of 112 means that thawing a filesystem failed.\n\ | |
f6b4ffdc MW |
331 | \n\ |
332 | Options:\n\ | |
333 | \n\ | |
334 | -h, --help Print this help text.\n\ | |
335 | -v, --version Print the program version number.\n\ | |
336 | -u, --usage Print a short usage message.\n\ | |
337 | \n\ | |
338 | -a, --address=ADDR Listen only on ADDR.\n\ | |
339 | -n, --not-really Don't really freeze or thaw filesystems.\n\ | |
340 | -p, --port-range=LO[-HI] Select a port number between LO and HI.\n\ | |
341 | If HI is omitted, choose only LO.\n\ | |
342 | ", fp); | |
343 | } | |
344 | ||
345 | /*----- Main program ------------------------------------------------------*/ | |
346 | ||
347 | int main(int argc, char *argv[]) | |
348 | { | |
349 | char buf[256]; | |
350 | int loport = -1, hiport = -1; | |
351 | int sk, fd, maxfd; | |
352 | struct sockaddr_in sin; | |
353 | socklen_t sasz; | |
354 | struct hostent *h; | |
355 | const char *p, *q; | |
356 | struct timeval now, when, delta; | |
357 | struct client *clients = 0, *c, **cc; | |
358 | const struct token *t; | |
359 | struct tokmatch tm; | |
360 | fd_set fdin; | |
361 | int i; | |
362 | ssize_t n; | |
363 | unsigned f = 0; | |
364 | #define f_bogus 0x01u | |
365 | #define f_notreally 0x02u | |
366 | ||
367 | ego(argv[0]); | |
368 | sub_init(); | |
369 | ||
370 | /* --- Partially initialize the socket address --- */ | |
371 | ||
372 | sin.sin_family = AF_INET; | |
373 | sin.sin_addr.s_addr = INADDR_ANY; | |
374 | sin.sin_port = 0; | |
375 | ||
376 | /* --- Parse the command line --- */ | |
377 | ||
378 | for (;;) { | |
379 | static struct option opts[] = { | |
380 | { "help", 0, 0, 'h' }, | |
381 | { "version", 0, 0, 'v' }, | |
382 | { "usage", 0, 0, 'u' }, | |
383 | { "address", OPTF_ARGREQ, 0, 'a' }, | |
384 | { "not-really", 0, 0, 'n' }, | |
385 | { "port-range", OPTF_ARGREQ, 0, 'p' }, | |
386 | { 0, 0, 0, 0 } | |
387 | }; | |
388 | ||
389 | if ((i = mdwopt(argc, argv, "hvua:np:", opts, 0, 0, 0)) < 0) break; | |
390 | switch (i) { | |
391 | case 'h': help(stdout); exit(0); | |
392 | case 'v': version(stdout); exit(0); | |
393 | case 'u': usage(stdout); exit(0); | |
394 | case 'a': | |
395 | if ((h = gethostbyname(optarg)) == 0) { | |
396 | die(1, "failed to resolve address `%s': %s", | |
397 | optarg, hstrerror(h_errno)); | |
398 | } | |
399 | if (h->h_addrtype != AF_INET) | |
400 | die(1, "unexpected address type resolving `%s'", optarg); | |
401 | assert(h->h_length == sizeof(sin.sin_addr)); | |
402 | memcpy(&sin.sin_addr, h->h_addr, sizeof(sin.sin_addr)); | |
403 | break; | |
404 | case 'n': f |= f_notreally; break; | |
405 | case 'p': | |
406 | if ((p = strchr(optarg, '-')) == 0) | |
407 | loport = hiport = getuint(optarg, 0); | |
408 | else { | |
409 | loport = getuint(optarg, p); | |
410 | hiport = getuint(p + 1, 0); | |
411 | } | |
412 | break; | |
413 | default: f |= f_bogus; break; | |
414 | } | |
415 | } | |
416 | if (f & f_bogus) { usage(stderr); exit(1); } | |
417 | if (optind >= argc) { usage(stderr); exit(1); } | |
418 | ||
419 | /* --- Open the file systems --- */ | |
420 | ||
421 | nfs = argc - optind; | |
422 | fsname = &argv[optind]; | |
423 | fs = xmalloc(nfs*sizeof(*fs)); | |
424 | for (i = 0; i < nfs; i++) { | |
425 | if ((fs[i] = open(fsname[i], O_RDONLY)) < 0) | |
426 | die(2, "open (%s): %s", fsname[i], strerror(errno)); | |
427 | } | |
428 | ||
429 | if (f & f_notreally) { | |
430 | for (i = 0; i < nfs; i++) { | |
431 | close(fs[i]); | |
432 | fs[i] = -1; | |
433 | } | |
434 | } | |
435 | ||
436 | /* --- Generate random tokens --- */ | |
437 | ||
438 | inittoks(); | |
439 | ||
440 | /* --- Create the listening socket --- */ | |
441 | ||
442 | if ((sk = socket(PF_INET, SOCK_STREAM, 0)) < 0) | |
443 | die(2, "socket: %s", strerror(errno)); | |
444 | i = 1; | |
445 | if (setsockopt(sk, SOL_SOCKET, SO_REUSEADDR, &i, sizeof(i))) | |
446 | die(2, "setsockopt (reuseaddr): %s", strerror(errno)); | |
447 | if (fdflags(sk, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC)) | |
448 | die(2, "fdflags: %s", strerror(errno)); | |
449 | if (loport < 0 || loport == hiport) { | |
450 | if (loport >= 0) sin.sin_port = htons(loport); | |
451 | if (bind(sk, (struct sockaddr *)&sin, sizeof(sin))) | |
452 | die(2, "bind: %s", strerror(errno)); | |
453 | } else if (hiport != loport) { | |
454 | for (i = loport; i <= hiport; i++) { | |
455 | sin.sin_port = htons(i); | |
456 | if (bind(sk, (struct sockaddr *)&sin, sizeof(sin)) >= 0) break; | |
457 | else if (errno != EADDRINUSE) | |
458 | die(2, "bind: %s", strerror(errno)); | |
459 | } | |
460 | if (i > hiport) die(2, "bind: all ports in use"); | |
461 | } | |
462 | if (listen(sk, 5)) die(2, "listen: %s", strerror(errno)); | |
463 | ||
464 | /* --- Tell the caller how to connect to us, and start the timer --- */ | |
465 | ||
466 | sasz = sizeof(sin); | |
467 | if (getsockname(sk, (struct sockaddr *)&sin, &sasz)) | |
468 | die(2, "getsockname (listen): %s", strerror(errno)); | |
469 | printf("PORT %d\n", ntohs(sin.sin_port)); | |
470 | for (t = toktab; t->label; t++) | |
471 | printf("TOKEN %s %s\n", t->label, t->tok); | |
472 | printf("READY\n"); | |
473 | if (fflush(stdout) || ferror(stdout)) | |
474 | die(2, "write (stdout, rubric): %s", strerror(errno)); | |
475 | gettimeofday(&now, 0); TV_ADDL(&when, &now, TO_CONNECT, 0); | |
476 | ||
477 | /* --- Collect incoming connections, and check for the cookie --- * | |
478 | * | |
479 | * This is the tricky part. | |
480 | */ | |
481 | ||
482 | for (;;) { | |
483 | FD_ZERO(&fdin); | |
484 | FD_SET(sk, &fdin); | |
485 | maxfd = sk; | |
486 | for (c = clients; c; c = c->next) { | |
487 | FD_SET(c->fd, &fdin); | |
488 | if (c->fd > maxfd) maxfd = c->fd; | |
489 | } | |
490 | TV_SUB(&delta, &when, &now); | |
491 | if (select(maxfd + 1, &fdin, 0, 0, &delta) < 0) | |
492 | die(2, "select (accept): %s", strerror(errno)); | |
493 | gettimeofday(&now, 0); | |
494 | ||
495 | if (TV_CMP(&now, >=, &when)) die(3, "timeout (accept)"); | |
496 | ||
497 | if (FD_ISSET(sk, &fdin)) { | |
498 | sasz = sizeof(sin); | |
499 | fd = accept(sk, (struct sockaddr *)&sin, &sasz); | |
500 | if (fd >= 0) { | |
501 | if (fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC) < 0) | |
502 | die(2, "fdflags: %s", strerror(errno)); | |
503 | c = CREATE(struct client); | |
504 | c->next = clients; c->fd = fd; tokmatch_init(&c->tm); | |
505 | clients = c; | |
506 | } | |
507 | #ifdef DEBUG | |
508 | else if (errno != EAGAIN) | |
509 | moan("accept: %s", strerror(errno)); | |
510 | #endif | |
511 | } | |
512 | ||
513 | for (cc = &clients; *cc;) { | |
514 | c = *cc; | |
515 | if (!FD_ISSET(c->fd, &fdin)) goto next_client; | |
516 | n = read(c->fd, buf, sizeof(buf)); | |
517 | if (!n) goto disconn; | |
518 | else if (n < 0) { | |
519 | if (errno == EAGAIN) goto next_client; | |
520 | D( moan("read (client; auth): %s", strerror(errno)); ) | |
521 | goto disconn; | |
522 | } else { | |
523 | for (p = buf, q = p + n; p < q; p++) { | |
524 | switch (tokmatch_update(&c->tm, *p)) { | |
525 | case 0: break; | |
526 | case TF_FREEZE: goto connected; | |
527 | default: | |
528 | D( moan("bad token from client"); ) | |
529 | goto disconn; | |
530 | } | |
531 | } | |
532 | } | |
533 | ||
534 | next_client: | |
535 | cc = &c->next; | |
536 | continue; | |
537 | ||
538 | disconn: | |
539 | close(c->fd); | |
540 | *cc = c->next; | |
541 | DESTROY(c); | |
542 | continue; | |
543 | } | |
544 | } | |
545 | ||
546 | connected: | |
547 | close(sk); sk = c->fd; | |
548 | while (clients) { | |
549 | if (clients->fd != sk) close(clients->fd); | |
550 | c = clients->next; | |
551 | DESTROY(clients); | |
552 | clients = c; | |
553 | } | |
554 | ||
555 | /* --- Establish signal handlers --- * | |
556 | * | |
557 | * Hopefully this will prevent bad things happening if we have an accident. | |
558 | */ | |
559 | ||
560 | for (i = 0; i < sizeof(sigcatch)/sizeof(sigcatch[0]); i++) { | |
561 | if (signal(sigcatch[i], sigmumble) == SIG_ERR) | |
562 | die(2, "signal (%d): %s", i, strerror(errno)); | |
563 | } | |
564 | atexit(cleanup); | |
565 | ||
566 | /* --- Prevent the OOM killer from clobbering us --- */ | |
567 | ||
568 | if ((fd = open("/proc/self/oom_adj", O_WRONLY)) < 0 || | |
569 | write(fd, "-17\n", 4) < 4 || | |
570 | close(fd)) | |
571 | die(2, "set oom_adj: %s", strerror(errno)); | |
572 | ||
573 | /* --- Actually freeze the filesystem --- */ | |
574 | ||
575 | for (i = 0; i < nfs; i++) { | |
576 | if (fs[i] == -1) | |
577 | moan("not really freezing %s", fsname[i]); | |
578 | else { | |
579 | if (ioctl(fs[i], FIFREEZE, 0) < 0) { | |
580 | partial_cleanup(i); | |
581 | die(2, "ioctl (freeze %s): %s", fsname[i], strerror(errno)); | |
582 | } | |
583 | } | |
584 | } | |
585 | if (writetok(T_FROZEN, sk)) { | |
586 | cleanup(); | |
587 | die(2, "write (frozen): %s", strerror(errno)); | |
588 | } | |
589 | ||
590 | /* --- Now wait for the other end to detach --- */ | |
591 | ||
592 | tokmatch_init(&tm); | |
593 | TV_ADDL(&when, &now, TO_KEEPALIVE, 0); | |
594 | for (p++; p < q; p++) { | |
595 | switch (tokmatch_update(&tm, *p)) { | |
596 | case 0: break; | |
597 | case TF_KEEPALIVE: tokmatch_init(&tm); break; | |
598 | case TF_THAW: goto done; | |
599 | default: cleanup(); die(3, "unknown token (keepalive)"); | |
600 | } | |
601 | } | |
602 | for (;;) { | |
603 | FD_ZERO(&fdin); | |
604 | FD_SET(sk, &fdin); | |
605 | TV_SUB(&delta, &when, &now); | |
606 | if (select(sk + 1, &fdin, 0, 0, &delta) < 0) { | |
607 | cleanup(); | |
608 | die(2, "select (keepalive): %s", strerror(errno)); | |
609 | } | |
610 | ||
611 | gettimeofday(&now, 0); | |
612 | if (TV_CMP(&now, >, &when)) { | |
613 | cleanup(); die(3, "timeout (keepalive)"); | |
614 | } | |
615 | if (FD_ISSET(sk, &fdin)) { | |
616 | n = read(sk, buf, sizeof(buf)); | |
617 | if (!n) { cleanup(); die(3, "end-of-file (keepalive)"); } | |
618 | else if (n < 0) { | |
619 | if (errno == EAGAIN) ; | |
620 | else { | |
621 | cleanup(); | |
622 | die(2, "read (client, keepalive): %s", strerror(errno)); | |
623 | } | |
624 | } else { | |
625 | for (p = buf, q = p + n; p < q; p++) { | |
626 | switch (tokmatch_update(&tm, *p)) { | |
627 | case 0: break; | |
628 | case TF_KEEPALIVE: | |
629 | TV_ADDL(&when, &now, TO_KEEPALIVE, 0); | |
630 | tokmatch_init(&tm); | |
631 | break; | |
632 | case TF_THAW: | |
633 | goto done; | |
634 | default: | |
635 | cleanup(); | |
636 | die(3, "unknown token (keepalive)"); | |
637 | } | |
638 | } | |
639 | } | |
640 | } | |
641 | } | |
642 | ||
643 | done: | |
644 | cleanup(); | |
645 | if (writetok(T_THAWED, sk)) | |
646 | die(2, "write (thaw): %s", strerror(errno)); | |
647 | close(sk); | |
648 | return (0); | |
649 | } | |
650 | ||
651 | /*----- That's all, folks -------------------------------------------------*/ |