| 1 | /* -*- c-file-style: "linux" -*- |
| 2 | * |
| 3 | * Copyright (C) 1996-2001 by Andrew Tridgell |
| 4 | * Copyright (C) Paul Mackerras 1996 |
| 5 | * Copyright (C) 2001, 2002 by Martin Pool <mbp@samba.org> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 20 | */ |
| 21 | |
| 22 | /** |
| 23 | * @file io.c |
| 24 | * |
| 25 | * Socket and pipe IO utilities used in rsync. |
| 26 | * |
| 27 | * rsync provides its own multiplexing system, which is used to send |
| 28 | * stderr and stdout over a single socket. We need this because |
| 29 | * stdout normally carries the binary data stream, and stderr all our |
| 30 | * error messages. |
| 31 | * |
| 32 | * For historical reasons this is off during the start of the |
| 33 | * connection, but it's switched on quite early using |
| 34 | * io_start_multiplex_out() and io_start_multiplex_in(). |
| 35 | **/ |
| 36 | |
| 37 | #include "rsync.h" |
| 38 | |
| 39 | /** If no timeout is specified then use a 60 second select timeout */ |
| 40 | #define SELECT_TIMEOUT 60 |
| 41 | |
| 42 | static int io_multiplexing_out; |
| 43 | static int io_multiplexing_in; |
| 44 | static int multiplex_in_fd = -1; |
| 45 | static int multiplex_out_fd = -1; |
| 46 | static time_t last_io; |
| 47 | static int no_flush; |
| 48 | |
| 49 | extern int bwlimit; |
| 50 | extern int verbose; |
| 51 | extern int io_timeout; |
| 52 | extern struct stats stats; |
| 53 | |
| 54 | |
| 55 | const char phase_unknown[] = "unknown"; |
| 56 | |
| 57 | /** |
| 58 | * The connection might be dropped at some point; perhaps because the |
| 59 | * remote instance crashed. Just giving the offset on the stream is |
| 60 | * not very helpful. So instead we try to make io_phase_name point to |
| 61 | * something useful. |
| 62 | * |
| 63 | * For buffered/multiplexed IO these names will be somewhat |
| 64 | * approximate; perhaps for ease of support we would rather make the |
| 65 | * buffer always flush when a single application-level IO finishes. |
| 66 | * |
| 67 | * @todo Perhaps we want some simple stack functionality, but there's |
| 68 | * no need to overdo it. |
| 69 | **/ |
| 70 | const char *io_write_phase = phase_unknown; |
| 71 | const char *io_read_phase = phase_unknown; |
| 72 | |
| 73 | /** Ignore EOF errors while reading a module listing if the remote |
| 74 | version is 24 or less. */ |
| 75 | int kludge_around_eof = False; |
| 76 | |
| 77 | |
| 78 | static int io_error_fd = -1; |
| 79 | static int io_filesfrom_f_in = -1; |
| 80 | static int io_filesfrom_f_out = -1; |
| 81 | static char io_filesfrom_buf[2048]; |
| 82 | static char *io_filesfrom_bp; |
| 83 | static char io_filesfrom_lastchar; |
| 84 | static int io_filesfrom_buflen; |
| 85 | |
| 86 | static void read_loop(int fd, char *buf, size_t len); |
| 87 | |
| 88 | static void check_timeout(void) |
| 89 | { |
| 90 | extern int am_server, am_daemon; |
| 91 | time_t t; |
| 92 | |
| 93 | err_list_push(); |
| 94 | |
| 95 | if (!io_timeout) return; |
| 96 | |
| 97 | if (!last_io) { |
| 98 | last_io = time(NULL); |
| 99 | return; |
| 100 | } |
| 101 | |
| 102 | t = time(NULL); |
| 103 | |
| 104 | if (last_io && io_timeout && (t-last_io) >= io_timeout) { |
| 105 | if (!am_server && !am_daemon) { |
| 106 | rprintf(FERROR,"io timeout after %d seconds - exiting\n", |
| 107 | (int)(t-last_io)); |
| 108 | } |
| 109 | exit_cleanup(RERR_TIMEOUT); |
| 110 | } |
| 111 | } |
| 112 | |
| 113 | /** Setup the fd used to propagate errors */ |
| 114 | void io_set_error_fd(int fd) |
| 115 | { |
| 116 | io_error_fd = fd; |
| 117 | } |
| 118 | |
| 119 | /** Read some data from the error fd and write it to the write log code */ |
| 120 | static void read_error_fd(void) |
| 121 | { |
| 122 | char buf[200]; |
| 123 | size_t n; |
| 124 | int fd = io_error_fd; |
| 125 | int tag, len; |
| 126 | |
| 127 | /* io_error_fd is temporarily disabled -- is this meant to |
| 128 | * prevent indefinite recursion? */ |
| 129 | io_error_fd = -1; |
| 130 | |
| 131 | read_loop(fd, buf, 4); |
| 132 | tag = IVAL(buf, 0); |
| 133 | |
| 134 | len = tag & 0xFFFFFF; |
| 135 | tag = tag >> 24; |
| 136 | tag -= MPLEX_BASE; |
| 137 | |
| 138 | while (len) { |
| 139 | n = len; |
| 140 | if (n > (sizeof buf - 1)) |
| 141 | n = sizeof buf - 1; |
| 142 | read_loop(fd, buf, n); |
| 143 | rwrite((enum logcode)tag, buf, n); |
| 144 | len -= n; |
| 145 | } |
| 146 | |
| 147 | io_error_fd = fd; |
| 148 | } |
| 149 | |
| 150 | /** |
| 151 | * When we're the receiver and we have a local --files-from list of names |
| 152 | * that needs to be sent over the socket to the sender, we have to do two |
| 153 | * things at the same time: send the sender a list of what files we're |
| 154 | * processing and read the incoming file+info list from the sender. We do |
| 155 | * this by augmenting the read_timeout() function to copy this data. It |
| 156 | * uses the io_filesfrom_buf to read a block of data from f_in (when it is |
| 157 | * ready, since it might be a pipe) and then blast it out f_out (when it |
| 158 | * is ready to receive more data). |
| 159 | */ |
| 160 | void io_set_filesfrom_fds(int f_in, int f_out) |
| 161 | { |
| 162 | io_filesfrom_f_in = f_in; |
| 163 | io_filesfrom_f_out = f_out; |
| 164 | io_filesfrom_bp = io_filesfrom_buf; |
| 165 | io_filesfrom_lastchar = '\0'; |
| 166 | io_filesfrom_buflen = 0; |
| 167 | } |
| 168 | |
| 169 | /** |
| 170 | * It's almost always an error to get an EOF when we're trying to read |
| 171 | * from the network, because the protocol is self-terminating. |
| 172 | * |
| 173 | * However, there is one unfortunate cases where it is not, which is |
| 174 | * rsync <2.4.6 sending a list of modules on a server, since the list |
| 175 | * is terminated by closing the socket. So, for the section of the |
| 176 | * program where that is a problem (start_socket_client), |
| 177 | * kludge_around_eof is True and we just exit. |
| 178 | */ |
| 179 | static void whine_about_eof(void) |
| 180 | { |
| 181 | if (kludge_around_eof) |
| 182 | exit_cleanup(0); |
| 183 | else { |
| 184 | rprintf(FERROR, |
| 185 | "%s: connection unexpectedly closed " |
| 186 | "(%.0f bytes read so far)\n", |
| 187 | RSYNC_NAME, (double)stats.total_read); |
| 188 | |
| 189 | exit_cleanup(RERR_STREAMIO); |
| 190 | } |
| 191 | } |
| 192 | |
| 193 | |
| 194 | static void die_from_readerr(int err) |
| 195 | { |
| 196 | /* this prevents us trying to write errors on a dead socket */ |
| 197 | io_multiplexing_close(); |
| 198 | |
| 199 | rprintf(FERROR, "%s: read error: %s\n", |
| 200 | RSYNC_NAME, strerror(err)); |
| 201 | exit_cleanup(RERR_STREAMIO); |
| 202 | } |
| 203 | |
| 204 | |
| 205 | /** |
| 206 | * Read from a socket with IO timeout. return the number of bytes |
| 207 | * read. If no bytes can be read then exit, never return a number <= 0. |
| 208 | * |
| 209 | * TODO: If the remote shell connection fails, then current versions |
| 210 | * actually report an "unexpected EOF" error here. Since it's a |
| 211 | * fairly common mistake to try to use rsh when ssh is required, we |
| 212 | * should trap that: if we fail to read any data at all, we should |
| 213 | * give a better explanation. We can tell whether the connection has |
| 214 | * started by looking e.g. at whether the remote version is known yet. |
| 215 | */ |
| 216 | static int read_timeout(int fd, char *buf, size_t len) |
| 217 | { |
| 218 | int n, ret=0; |
| 219 | |
| 220 | io_flush(); |
| 221 | |
| 222 | while (ret == 0) { |
| 223 | /* until we manage to read *something* */ |
| 224 | fd_set r_fds, w_fds; |
| 225 | struct timeval tv; |
| 226 | int fd_count = fd+1; |
| 227 | int count; |
| 228 | |
| 229 | FD_ZERO(&r_fds); |
| 230 | FD_SET(fd, &r_fds); |
| 231 | if (io_error_fd >= 0) { |
| 232 | FD_SET(io_error_fd, &r_fds); |
| 233 | if (io_error_fd >= fd_count) fd_count = io_error_fd+1; |
| 234 | } |
| 235 | if (io_filesfrom_f_out >= 0) { |
| 236 | int new_fd; |
| 237 | if (io_filesfrom_buflen == 0) { |
| 238 | if (io_filesfrom_f_in >= 0) { |
| 239 | FD_SET(io_filesfrom_f_in, &r_fds); |
| 240 | new_fd = io_filesfrom_f_in; |
| 241 | } else { |
| 242 | io_filesfrom_f_out = -1; |
| 243 | new_fd = -1; |
| 244 | } |
| 245 | } else { |
| 246 | FD_ZERO(&w_fds); |
| 247 | FD_SET(io_filesfrom_f_out, &w_fds); |
| 248 | new_fd = io_filesfrom_f_out; |
| 249 | } |
| 250 | if (new_fd >= fd_count) fd_count = new_fd+1; |
| 251 | } |
| 252 | |
| 253 | tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT; |
| 254 | tv.tv_usec = 0; |
| 255 | |
| 256 | errno = 0; |
| 257 | |
| 258 | count = select(fd_count, &r_fds, |
| 259 | io_filesfrom_buflen? &w_fds : NULL, |
| 260 | NULL, &tv); |
| 261 | |
| 262 | if (count == 0) { |
| 263 | check_timeout(); |
| 264 | } |
| 265 | |
| 266 | if (count <= 0) { |
| 267 | if (errno == EBADF) { |
| 268 | exit_cleanup(RERR_SOCKETIO); |
| 269 | } |
| 270 | continue; |
| 271 | } |
| 272 | |
| 273 | if (io_error_fd >= 0 && FD_ISSET(io_error_fd, &r_fds)) { |
| 274 | read_error_fd(); |
| 275 | } |
| 276 | |
| 277 | if (io_filesfrom_f_out >= 0) { |
| 278 | if (io_filesfrom_buflen) { |
| 279 | if (FD_ISSET(io_filesfrom_f_out, &w_fds)) { |
| 280 | int l = write(io_filesfrom_f_out, |
| 281 | io_filesfrom_bp, |
| 282 | io_filesfrom_buflen); |
| 283 | if (l > 0) { |
| 284 | if (!(io_filesfrom_buflen -= l)) |
| 285 | io_filesfrom_bp = io_filesfrom_buf; |
| 286 | else |
| 287 | io_filesfrom_bp += l; |
| 288 | } else { |
| 289 | /* XXX should we complain? */ |
| 290 | io_filesfrom_f_out = -1; |
| 291 | } |
| 292 | } |
| 293 | } else if (io_filesfrom_f_in >= 0) { |
| 294 | if (FD_ISSET(io_filesfrom_f_in, &r_fds)) { |
| 295 | int l = read(io_filesfrom_f_in, |
| 296 | io_filesfrom_buf, |
| 297 | sizeof io_filesfrom_buf); |
| 298 | if (l <= 0) { |
| 299 | /* Send end-of-file marker */ |
| 300 | io_filesfrom_buf[0] = '\0'; |
| 301 | io_filesfrom_buf[1] = '\0'; |
| 302 | io_filesfrom_buflen = io_filesfrom_lastchar? 2 : 1; |
| 303 | io_filesfrom_f_in = -1; |
| 304 | } else { |
| 305 | extern int eol_nulls; |
| 306 | if (!eol_nulls) { |
| 307 | char *s = io_filesfrom_buf + l; |
| 308 | /* Transform CR and/or LF into '\0' */ |
| 309 | while (s-- > io_filesfrom_buf) { |
| 310 | if (*s == '\n' || *s == '\r') |
| 311 | *s = '\0'; |
| 312 | } |
| 313 | } |
| 314 | if (!io_filesfrom_lastchar) { |
| 315 | /* Last buf ended with a '\0', so don't |
| 316 | * let this buf start with one. */ |
| 317 | while (l && !*io_filesfrom_bp) |
| 318 | io_filesfrom_bp++, l--; |
| 319 | } |
| 320 | if (!l) |
| 321 | io_filesfrom_bp = io_filesfrom_buf; |
| 322 | else { |
| 323 | char *f = io_filesfrom_bp; |
| 324 | char *t = f; |
| 325 | char *eob = f + l; |
| 326 | /* Eliminate any multi-'\0' runs. */ |
| 327 | while (f != eob) { |
| 328 | if (!(*t++ = *f++)) { |
| 329 | while (f != eob && !*f) |
| 330 | f++, l--; |
| 331 | } |
| 332 | } |
| 333 | io_filesfrom_lastchar = f[-1]; |
| 334 | } |
| 335 | io_filesfrom_buflen = l; |
| 336 | } |
| 337 | } |
| 338 | } |
| 339 | } |
| 340 | |
| 341 | if (!FD_ISSET(fd, &r_fds)) continue; |
| 342 | |
| 343 | n = read(fd, buf, len); |
| 344 | |
| 345 | if (n > 0) { |
| 346 | buf += n; |
| 347 | len -= n; |
| 348 | ret += n; |
| 349 | if (io_timeout) |
| 350 | last_io = time(NULL); |
| 351 | continue; |
| 352 | } else if (n == 0) { |
| 353 | whine_about_eof(); |
| 354 | return -1; /* doesn't return */ |
| 355 | } else if (n < 0) { |
| 356 | if (errno == EINTR || errno == EWOULDBLOCK || |
| 357 | errno == EAGAIN) |
| 358 | continue; |
| 359 | die_from_readerr(errno); |
| 360 | } |
| 361 | } |
| 362 | |
| 363 | return ret; |
| 364 | } |
| 365 | |
| 366 | /** |
| 367 | * Read a line into the "fname" buffer (which must be at least MAXPATHLEN |
| 368 | * characters long). |
| 369 | */ |
| 370 | int read_filesfrom_line(int fd, char *fname) |
| 371 | { |
| 372 | char ch, *s, *eob = fname + MAXPATHLEN - 1; |
| 373 | int cnt; |
| 374 | extern int io_timeout; |
| 375 | extern int eol_nulls; |
| 376 | extern char *remote_filesfrom_file; |
| 377 | int reading_remotely = remote_filesfrom_file != NULL; |
| 378 | int nulls = eol_nulls || reading_remotely; |
| 379 | |
| 380 | start: |
| 381 | s = fname; |
| 382 | while (1) { |
| 383 | cnt = read(fd, &ch, 1); |
| 384 | if (cnt < 0 && (errno == EWOULDBLOCK |
| 385 | || errno == EINTR || errno == EAGAIN)) { |
| 386 | struct timeval tv; |
| 387 | fd_set fds; |
| 388 | FD_ZERO(&fds); |
| 389 | FD_SET(fd, &fds); |
| 390 | tv.tv_sec = io_timeout? io_timeout : SELECT_TIMEOUT; |
| 391 | tv.tv_usec = 0; |
| 392 | if (!select(fd+1, &fds, NULL, NULL, &tv)) |
| 393 | check_timeout(); |
| 394 | continue; |
| 395 | } |
| 396 | if (cnt != 1) |
| 397 | break; |
| 398 | if (nulls? !ch : (ch == '\r' || ch == '\n')) { |
| 399 | /* Skip empty lines if reading locally. */ |
| 400 | if (!reading_remotely && s == fname) |
| 401 | continue; |
| 402 | break; |
| 403 | } |
| 404 | if (s < eob) |
| 405 | *s++ = ch; |
| 406 | } |
| 407 | *s = '\0'; |
| 408 | |
| 409 | /* Dump comments. */ |
| 410 | if (*fname == '#' || *fname == ';') |
| 411 | goto start; |
| 412 | |
| 413 | return s - fname; |
| 414 | } |
| 415 | |
| 416 | |
| 417 | /** |
| 418 | * Continue trying to read len bytes - don't return until len has been |
| 419 | * read. |
| 420 | **/ |
| 421 | static void read_loop(int fd, char *buf, size_t len) |
| 422 | { |
| 423 | while (len) { |
| 424 | int n = read_timeout(fd, buf, len); |
| 425 | |
| 426 | buf += n; |
| 427 | len -= n; |
| 428 | } |
| 429 | } |
| 430 | |
| 431 | |
| 432 | /** |
| 433 | * Read from the file descriptor handling multiplexing - return number |
| 434 | * of bytes read. |
| 435 | * |
| 436 | * Never returns <= 0. |
| 437 | */ |
| 438 | static int read_unbuffered(int fd, char *buf, size_t len) |
| 439 | { |
| 440 | static size_t remaining; |
| 441 | int tag, ret = 0; |
| 442 | char line[1024]; |
| 443 | static char *buffer; |
| 444 | static size_t bufferIdx = 0; |
| 445 | static size_t bufferSz; |
| 446 | |
| 447 | if (fd != multiplex_in_fd) |
| 448 | return read_timeout(fd, buf, len); |
| 449 | |
| 450 | if (!io_multiplexing_in && remaining == 0) { |
| 451 | if (!buffer) { |
| 452 | bufferSz = 2 * IO_BUFFER_SIZE; |
| 453 | buffer = new_array(char, bufferSz); |
| 454 | if (!buffer) out_of_memory("read_unbuffered"); |
| 455 | } |
| 456 | remaining = read_timeout(fd, buffer, bufferSz); |
| 457 | bufferIdx = 0; |
| 458 | } |
| 459 | |
| 460 | while (ret == 0) { |
| 461 | if (remaining) { |
| 462 | len = MIN(len, remaining); |
| 463 | memcpy(buf, buffer + bufferIdx, len); |
| 464 | bufferIdx += len; |
| 465 | remaining -= len; |
| 466 | ret = len; |
| 467 | break; |
| 468 | } |
| 469 | |
| 470 | read_loop(fd, line, 4); |
| 471 | tag = IVAL(line, 0); |
| 472 | |
| 473 | remaining = tag & 0xFFFFFF; |
| 474 | tag = tag >> 24; |
| 475 | |
| 476 | if (tag == MPLEX_BASE) { |
| 477 | if (!buffer || remaining > bufferSz) { |
| 478 | buffer = realloc_array(buffer, char, remaining); |
| 479 | if (!buffer) out_of_memory("read_unbuffered"); |
| 480 | bufferSz = remaining; |
| 481 | } |
| 482 | read_loop(fd, buffer, remaining); |
| 483 | bufferIdx = 0; |
| 484 | continue; |
| 485 | } |
| 486 | |
| 487 | tag -= MPLEX_BASE; |
| 488 | |
| 489 | if (tag != FERROR && tag != FINFO) { |
| 490 | rprintf(FERROR, "unexpected tag %d\n", tag); |
| 491 | exit_cleanup(RERR_STREAMIO); |
| 492 | } |
| 493 | |
| 494 | if (remaining > sizeof line - 1) { |
| 495 | rprintf(FERROR, "multiplexing overflow %ld\n\n", |
| 496 | (long)remaining); |
| 497 | exit_cleanup(RERR_STREAMIO); |
| 498 | } |
| 499 | |
| 500 | read_loop(fd, line, remaining); |
| 501 | line[remaining] = 0; |
| 502 | |
| 503 | rprintf((enum logcode) tag, "%s", line); |
| 504 | remaining = 0; |
| 505 | } |
| 506 | |
| 507 | if (remaining == 0) |
| 508 | io_flush(); |
| 509 | |
| 510 | return ret; |
| 511 | } |
| 512 | |
| 513 | |
| 514 | |
| 515 | /** |
| 516 | * Do a buffered read from @p fd. Don't return until all @p n bytes |
| 517 | * have been read. If all @p n can't be read then exit with an |
| 518 | * error. |
| 519 | **/ |
| 520 | static void readfd(int fd, char *buffer, size_t N) |
| 521 | { |
| 522 | int ret; |
| 523 | size_t total=0; |
| 524 | |
| 525 | while (total < N) { |
| 526 | ret = read_unbuffered(fd, buffer + total, N-total); |
| 527 | total += ret; |
| 528 | } |
| 529 | |
| 530 | stats.total_read += total; |
| 531 | } |
| 532 | |
| 533 | |
| 534 | int32 read_int(int f) |
| 535 | { |
| 536 | char b[4]; |
| 537 | int32 ret; |
| 538 | |
| 539 | readfd(f,b,4); |
| 540 | ret = IVAL(b,0); |
| 541 | if (ret == (int32)0xffffffff) return -1; |
| 542 | return ret; |
| 543 | } |
| 544 | |
| 545 | int64 read_longint(int f) |
| 546 | { |
| 547 | int64 ret; |
| 548 | char b[8]; |
| 549 | ret = read_int(f); |
| 550 | |
| 551 | if ((int32)ret != (int32)0xffffffff) { |
| 552 | return ret; |
| 553 | } |
| 554 | |
| 555 | #ifdef NO_INT64 |
| 556 | rprintf(FERROR,"Integer overflow - attempted 64 bit offset\n"); |
| 557 | exit_cleanup(RERR_UNSUPPORTED); |
| 558 | #else |
| 559 | readfd(f,b,8); |
| 560 | ret = IVAL(b,0) | (((int64)IVAL(b,4))<<32); |
| 561 | #endif |
| 562 | |
| 563 | return ret; |
| 564 | } |
| 565 | |
| 566 | void read_buf(int f,char *buf,size_t len) |
| 567 | { |
| 568 | readfd(f,buf,len); |
| 569 | } |
| 570 | |
| 571 | void read_sbuf(int f,char *buf,size_t len) |
| 572 | { |
| 573 | read_buf(f,buf,len); |
| 574 | buf[len] = 0; |
| 575 | } |
| 576 | |
| 577 | unsigned char read_byte(int f) |
| 578 | { |
| 579 | unsigned char c; |
| 580 | read_buf(f, (char *)&c, 1); |
| 581 | return c; |
| 582 | } |
| 583 | |
| 584 | |
| 585 | /** |
| 586 | * Sleep after writing to limit I/O bandwidth usage. |
| 587 | * |
| 588 | * @todo Rather than sleeping after each write, it might be better to |
| 589 | * use some kind of averaging. The current algorithm seems to always |
| 590 | * use a bit less bandwidth than specified, because it doesn't make up |
| 591 | * for slow periods. But arguably this is a feature. In addition, we |
| 592 | * ought to take the time used to write the data into account. |
| 593 | **/ |
| 594 | static void sleep_for_bwlimit(int bytes_written) |
| 595 | { |
| 596 | struct timeval tv; |
| 597 | |
| 598 | if (!bwlimit) |
| 599 | return; |
| 600 | |
| 601 | assert(bytes_written > 0); |
| 602 | assert(bwlimit > 0); |
| 603 | |
| 604 | tv.tv_usec = bytes_written * 1000 / bwlimit; |
| 605 | tv.tv_sec = tv.tv_usec / 1000000; |
| 606 | tv.tv_usec = tv.tv_usec % 1000000; |
| 607 | |
| 608 | select(0, NULL, NULL, NULL, &tv); |
| 609 | } |
| 610 | |
| 611 | |
| 612 | /** |
| 613 | * Write len bytes to the file descriptor @p fd. |
| 614 | * |
| 615 | * This function underlies the multiplexing system. The body of the |
| 616 | * application never calls this function directly. |
| 617 | **/ |
| 618 | static void writefd_unbuffered(int fd,char *buf,size_t len) |
| 619 | { |
| 620 | size_t total = 0; |
| 621 | fd_set w_fds, r_fds; |
| 622 | int fd_count, count; |
| 623 | struct timeval tv; |
| 624 | |
| 625 | err_list_push(); |
| 626 | |
| 627 | no_flush++; |
| 628 | |
| 629 | while (total < len) { |
| 630 | FD_ZERO(&w_fds); |
| 631 | FD_SET(fd,&w_fds); |
| 632 | fd_count = fd; |
| 633 | |
| 634 | if (io_error_fd >= 0) { |
| 635 | FD_ZERO(&r_fds); |
| 636 | FD_SET(io_error_fd,&r_fds); |
| 637 | if (io_error_fd > fd_count) |
| 638 | fd_count = io_error_fd; |
| 639 | } |
| 640 | |
| 641 | tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT; |
| 642 | tv.tv_usec = 0; |
| 643 | |
| 644 | errno = 0; |
| 645 | |
| 646 | count = select(fd_count+1, |
| 647 | io_error_fd >= 0?&r_fds:NULL, |
| 648 | &w_fds,NULL, |
| 649 | &tv); |
| 650 | |
| 651 | if (count == 0) { |
| 652 | check_timeout(); |
| 653 | } |
| 654 | |
| 655 | if (count <= 0) { |
| 656 | if (errno == EBADF) { |
| 657 | exit_cleanup(RERR_SOCKETIO); |
| 658 | } |
| 659 | continue; |
| 660 | } |
| 661 | |
| 662 | if (io_error_fd >= 0 && FD_ISSET(io_error_fd, &r_fds)) { |
| 663 | read_error_fd(); |
| 664 | } |
| 665 | |
| 666 | if (FD_ISSET(fd, &w_fds)) { |
| 667 | int ret; |
| 668 | size_t n = len-total; |
| 669 | ret = write(fd,buf+total,n); |
| 670 | |
| 671 | if (ret < 0) { |
| 672 | if (errno == EINTR) |
| 673 | continue; |
| 674 | if (errno == EWOULDBLOCK || errno == EAGAIN) { |
| 675 | msleep(1); |
| 676 | continue; |
| 677 | } |
| 678 | } |
| 679 | |
| 680 | if (ret <= 0) { |
| 681 | /* Don't try to write errors back |
| 682 | * across the stream */ |
| 683 | io_multiplexing_close(); |
| 684 | rprintf(FERROR, RSYNC_NAME |
| 685 | ": writefd_unbuffered failed to write %ld bytes: phase \"%s\": %s\n", |
| 686 | (long) len, io_write_phase, |
| 687 | strerror(errno)); |
| 688 | exit_cleanup(RERR_STREAMIO); |
| 689 | } |
| 690 | |
| 691 | sleep_for_bwlimit(ret); |
| 692 | |
| 693 | total += ret; |
| 694 | |
| 695 | if (io_timeout) |
| 696 | last_io = time(NULL); |
| 697 | } |
| 698 | } |
| 699 | |
| 700 | no_flush--; |
| 701 | } |
| 702 | |
| 703 | |
| 704 | static char *io_buffer; |
| 705 | static int io_buffer_count; |
| 706 | |
| 707 | void io_start_buffering_out(int fd) |
| 708 | { |
| 709 | if (io_buffer) return; |
| 710 | multiplex_out_fd = fd; |
| 711 | io_buffer = new_array(char, IO_BUFFER_SIZE); |
| 712 | if (!io_buffer) out_of_memory("writefd"); |
| 713 | io_buffer_count = 0; |
| 714 | } |
| 715 | |
| 716 | void io_start_buffering_in(int fd) |
| 717 | { |
| 718 | multiplex_in_fd = fd; |
| 719 | } |
| 720 | |
| 721 | /** |
| 722 | * Write an message to a multiplexed stream. If this fails then rsync |
| 723 | * exits. |
| 724 | **/ |
| 725 | static void mplex_write(int fd, enum logcode code, char *buf, size_t len) |
| 726 | { |
| 727 | char buffer[4096]; |
| 728 | size_t n = len; |
| 729 | |
| 730 | SIVAL(buffer, 0, ((MPLEX_BASE + (int)code)<<24) + len); |
| 731 | |
| 732 | if (n > (sizeof buffer - 4)) { |
| 733 | n = sizeof buffer - 4; |
| 734 | } |
| 735 | |
| 736 | memcpy(&buffer[4], buf, n); |
| 737 | writefd_unbuffered(fd, buffer, n+4); |
| 738 | |
| 739 | len -= n; |
| 740 | buf += n; |
| 741 | |
| 742 | if (len) { |
| 743 | writefd_unbuffered(fd, buf, len); |
| 744 | } |
| 745 | } |
| 746 | |
| 747 | |
| 748 | void io_flush(void) |
| 749 | { |
| 750 | int fd = multiplex_out_fd; |
| 751 | |
| 752 | err_list_push(); |
| 753 | |
| 754 | if (!io_buffer_count || no_flush) return; |
| 755 | |
| 756 | if (io_multiplexing_out) { |
| 757 | mplex_write(fd, FNONE, io_buffer, io_buffer_count); |
| 758 | } else { |
| 759 | writefd_unbuffered(fd, io_buffer, io_buffer_count); |
| 760 | } |
| 761 | io_buffer_count = 0; |
| 762 | } |
| 763 | |
| 764 | |
| 765 | void io_end_buffering(void) |
| 766 | { |
| 767 | io_flush(); |
| 768 | if (!io_multiplexing_out) { |
| 769 | free(io_buffer); |
| 770 | io_buffer = NULL; |
| 771 | } |
| 772 | } |
| 773 | |
| 774 | static void writefd(int fd,char *buf,size_t len) |
| 775 | { |
| 776 | stats.total_written += len; |
| 777 | |
| 778 | err_list_push(); |
| 779 | |
| 780 | if (!io_buffer || fd != multiplex_out_fd) { |
| 781 | writefd_unbuffered(fd, buf, len); |
| 782 | return; |
| 783 | } |
| 784 | |
| 785 | while (len) { |
| 786 | int n = MIN((int) len, IO_BUFFER_SIZE-io_buffer_count); |
| 787 | if (n > 0) { |
| 788 | memcpy(io_buffer+io_buffer_count, buf, n); |
| 789 | buf += n; |
| 790 | len -= n; |
| 791 | io_buffer_count += n; |
| 792 | } |
| 793 | |
| 794 | if (io_buffer_count == IO_BUFFER_SIZE) io_flush(); |
| 795 | } |
| 796 | } |
| 797 | |
| 798 | |
| 799 | void write_int(int f,int32 x) |
| 800 | { |
| 801 | char b[4]; |
| 802 | SIVAL(b,0,x); |
| 803 | writefd(f,b,4); |
| 804 | } |
| 805 | |
| 806 | |
| 807 | void write_int_named(int f, int32 x, const char *phase) |
| 808 | { |
| 809 | io_write_phase = phase; |
| 810 | write_int(f, x); |
| 811 | io_write_phase = phase_unknown; |
| 812 | } |
| 813 | |
| 814 | |
| 815 | /* |
| 816 | * Note: int64 may actually be a 32-bit type if ./configure couldn't find any |
| 817 | * 64-bit types on this platform. |
| 818 | */ |
| 819 | void write_longint(int f, int64 x) |
| 820 | { |
| 821 | char b[8]; |
| 822 | |
| 823 | if (x <= 0x7FFFFFFF) { |
| 824 | write_int(f, (int)x); |
| 825 | return; |
| 826 | } |
| 827 | |
| 828 | #ifdef NO_INT64 |
| 829 | rprintf(FERROR,"Integer overflow - attempted 64 bit offset\n"); |
| 830 | exit_cleanup(RERR_UNSUPPORTED); |
| 831 | #else |
| 832 | write_int(f, (int32)0xFFFFFFFF); |
| 833 | SIVAL(b,0,(x&0xFFFFFFFF)); |
| 834 | SIVAL(b,4,((x>>32)&0xFFFFFFFF)); |
| 835 | |
| 836 | writefd(f,b,8); |
| 837 | #endif |
| 838 | } |
| 839 | |
| 840 | void write_buf(int f,char *buf,size_t len) |
| 841 | { |
| 842 | writefd(f,buf,len); |
| 843 | } |
| 844 | |
| 845 | /** Write a string to the connection */ |
| 846 | static void write_sbuf(int f,char *buf) |
| 847 | { |
| 848 | write_buf(f, buf, strlen(buf)); |
| 849 | } |
| 850 | |
| 851 | |
| 852 | void write_byte(int f,unsigned char c) |
| 853 | { |
| 854 | write_buf(f,(char *)&c,1); |
| 855 | } |
| 856 | |
| 857 | |
| 858 | |
| 859 | /** |
| 860 | * Read a line of up to @p maxlen characters into @p buf. Does not |
| 861 | * contain a trailing newline or carriage return. |
| 862 | * |
| 863 | * @return 1 for success; 0 for io error or truncation. |
| 864 | **/ |
| 865 | int read_line(int f, char *buf, size_t maxlen) |
| 866 | { |
| 867 | while (maxlen) { |
| 868 | buf[0] = 0; |
| 869 | read_buf(f, buf, 1); |
| 870 | if (buf[0] == 0) |
| 871 | return 0; |
| 872 | if (buf[0] == '\n') { |
| 873 | buf[0] = 0; |
| 874 | break; |
| 875 | } |
| 876 | if (buf[0] != '\r') { |
| 877 | buf++; |
| 878 | maxlen--; |
| 879 | } |
| 880 | } |
| 881 | if (maxlen == 0) { |
| 882 | *buf = 0; |
| 883 | return 0; |
| 884 | } |
| 885 | |
| 886 | return 1; |
| 887 | } |
| 888 | |
| 889 | |
| 890 | void io_printf(int fd, const char *format, ...) |
| 891 | { |
| 892 | va_list ap; |
| 893 | char buf[1024]; |
| 894 | int len; |
| 895 | |
| 896 | va_start(ap, format); |
| 897 | len = vsnprintf(buf, sizeof buf, format, ap); |
| 898 | va_end(ap); |
| 899 | |
| 900 | if (len < 0) exit_cleanup(RERR_STREAMIO); |
| 901 | |
| 902 | write_sbuf(fd, buf); |
| 903 | } |
| 904 | |
| 905 | |
| 906 | /** Setup for multiplexing an error stream with the data stream */ |
| 907 | void io_start_multiplex_out(int fd) |
| 908 | { |
| 909 | multiplex_out_fd = fd; |
| 910 | io_flush(); |
| 911 | io_start_buffering_out(fd); |
| 912 | io_multiplexing_out = 1; |
| 913 | } |
| 914 | |
| 915 | /** Setup for multiplexing an error stream with the data stream */ |
| 916 | void io_start_multiplex_in(int fd) |
| 917 | { |
| 918 | multiplex_in_fd = fd; |
| 919 | io_flush(); |
| 920 | io_multiplexing_in = 1; |
| 921 | } |
| 922 | |
| 923 | /** Write an message to the multiplexed error stream */ |
| 924 | int io_multiplex_write(enum logcode code, char *buf, size_t len) |
| 925 | { |
| 926 | if (!io_multiplexing_out) return 0; |
| 927 | |
| 928 | io_flush(); |
| 929 | stats.total_written += (len+4); |
| 930 | mplex_write(multiplex_out_fd, code, buf, len); |
| 931 | return 1; |
| 932 | } |
| 933 | |
| 934 | /** Stop output multiplexing */ |
| 935 | void io_multiplexing_close(void) |
| 936 | { |
| 937 | io_multiplexing_out = 0; |
| 938 | } |
| 939 | |