| 1 | /* -*- c-file-style: "linux" -*- |
| 2 | |
| 3 | Copyright (C) 1996-2001 by Andrew Tridgell |
| 4 | Copyright (C) Paul Mackerras 1996 |
| 5 | |
| 6 | This program is free software; you can redistribute it and/or modify |
| 7 | it under the terms of the GNU General Public License as published by |
| 8 | the Free Software Foundation; either version 2 of the License, or |
| 9 | (at your option) any later version. |
| 10 | |
| 11 | This program is distributed in the hope that it will be useful, |
| 12 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 13 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 14 | GNU General Public License for more details. |
| 15 | |
| 16 | You should have received a copy of the GNU General Public License |
| 17 | along with this program; if not, write to the Free Software |
| 18 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 19 | */ |
| 20 | |
| 21 | /* |
| 22 | socket and pipe IO utilities used in rsync |
| 23 | |
| 24 | tridge, June 1996 |
| 25 | */ |
| 26 | #include "rsync.h" |
| 27 | |
| 28 | /* if no timeout is specified then use a 60 second select timeout */ |
| 29 | #define SELECT_TIMEOUT 60 |
| 30 | |
| 31 | extern int bwlimit; |
| 32 | |
| 33 | static int io_multiplexing_out; |
| 34 | static int io_multiplexing_in; |
| 35 | static int multiplex_in_fd; |
| 36 | static int multiplex_out_fd; |
| 37 | static time_t last_io; |
| 38 | static int eof_error=1; |
| 39 | extern int verbose; |
| 40 | extern int io_timeout; |
| 41 | extern struct stats stats; |
| 42 | |
| 43 | static int io_error_fd = -1; |
| 44 | |
| 45 | static void read_loop(int fd, char *buf, int len); |
| 46 | |
| 47 | static void check_timeout(void) |
| 48 | { |
| 49 | extern int am_server, am_daemon; |
| 50 | time_t t; |
| 51 | |
| 52 | if (!io_timeout) return; |
| 53 | |
| 54 | if (!last_io) { |
| 55 | last_io = time(NULL); |
| 56 | return; |
| 57 | } |
| 58 | |
| 59 | t = time(NULL); |
| 60 | |
| 61 | if (last_io && io_timeout && (t-last_io) >= io_timeout) { |
| 62 | if (!am_server && !am_daemon) { |
| 63 | rprintf(FERROR,"io timeout after %d seconds - exiting\n", |
| 64 | (int)(t-last_io)); |
| 65 | } |
| 66 | exit_cleanup(RERR_TIMEOUT); |
| 67 | } |
| 68 | } |
| 69 | |
| 70 | /* setup the fd used to propogate errors */ |
| 71 | void io_set_error_fd(int fd) |
| 72 | { |
| 73 | io_error_fd = fd; |
| 74 | } |
| 75 | |
| 76 | /* read some data from the error fd and write it to the write log code */ |
| 77 | static void read_error_fd(void) |
| 78 | { |
| 79 | char buf[200]; |
| 80 | int n; |
| 81 | int fd = io_error_fd; |
| 82 | int tag, len; |
| 83 | |
| 84 | io_error_fd = -1; |
| 85 | |
| 86 | read_loop(fd, buf, 4); |
| 87 | tag = IVAL(buf, 0); |
| 88 | |
| 89 | len = tag & 0xFFFFFF; |
| 90 | tag = tag >> 24; |
| 91 | tag -= MPLEX_BASE; |
| 92 | |
| 93 | while (len) { |
| 94 | n = len; |
| 95 | if (n > (sizeof(buf)-1)) n = sizeof(buf)-1; |
| 96 | read_loop(fd, buf, n); |
| 97 | rwrite((enum logcode)tag, buf, n); |
| 98 | len -= n; |
| 99 | } |
| 100 | |
| 101 | io_error_fd = fd; |
| 102 | } |
| 103 | |
| 104 | |
| 105 | static int no_flush; |
| 106 | |
| 107 | /* |
| 108 | * Read from a socket with IO timeout. return the number of bytes |
| 109 | * read. If no bytes can be read then exit, never return a number <= 0. |
| 110 | * |
| 111 | * TODO: If the remote shell connection fails, then current versions actually |
| 112 | * report an "unexpected EOF" error here. Since it's a fairly common mistake |
| 113 | * to try to use rsh when ssh is required, we should trap that: if we fail |
| 114 | * to read any data at all, we should give a better explanation. |
| 115 | */ |
| 116 | static int read_timeout(int fd, char *buf, int len) |
| 117 | { |
| 118 | int n, ret=0; |
| 119 | |
| 120 | io_flush(); |
| 121 | |
| 122 | while (ret == 0) { |
| 123 | fd_set fds; |
| 124 | struct timeval tv; |
| 125 | int fd_count = fd+1; |
| 126 | |
| 127 | FD_ZERO(&fds); |
| 128 | FD_SET(fd, &fds); |
| 129 | if (io_error_fd != -1) { |
| 130 | FD_SET(io_error_fd, &fds); |
| 131 | if (io_error_fd > fd) fd_count = io_error_fd+1; |
| 132 | } |
| 133 | |
| 134 | tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT; |
| 135 | tv.tv_usec = 0; |
| 136 | |
| 137 | errno = 0; |
| 138 | |
| 139 | if (select(fd_count, &fds, NULL, NULL, &tv) < 1) { |
| 140 | if (errno == EBADF) { |
| 141 | exit_cleanup(RERR_SOCKETIO); |
| 142 | } |
| 143 | check_timeout(); |
| 144 | continue; |
| 145 | } |
| 146 | |
| 147 | if (io_error_fd != -1 && FD_ISSET(io_error_fd, &fds)) { |
| 148 | read_error_fd(); |
| 149 | } |
| 150 | |
| 151 | if (!FD_ISSET(fd, &fds)) continue; |
| 152 | |
| 153 | n = read(fd, buf, len); |
| 154 | |
| 155 | if (n > 0) { |
| 156 | buf += n; |
| 157 | len -= n; |
| 158 | ret += n; |
| 159 | if (io_timeout) |
| 160 | last_io = time(NULL); |
| 161 | continue; |
| 162 | } |
| 163 | |
| 164 | if (n == -1 && errno == EINTR) { |
| 165 | continue; |
| 166 | } |
| 167 | |
| 168 | if (n == -1 && |
| 169 | (errno == EWOULDBLOCK || errno == EAGAIN)) { |
| 170 | continue; |
| 171 | } |
| 172 | |
| 173 | |
| 174 | if (n == 0) { |
| 175 | if (eof_error) { |
| 176 | rprintf(FERROR,"unexpected EOF in read_timeout\n"); |
| 177 | } |
| 178 | exit_cleanup(RERR_STREAMIO); |
| 179 | } |
| 180 | |
| 181 | /* this prevents us trying to write errors on a dead socket */ |
| 182 | io_multiplexing_close(); |
| 183 | |
| 184 | rprintf(FERROR,"read error: %s\n", strerror(errno)); |
| 185 | exit_cleanup(RERR_STREAMIO); |
| 186 | } |
| 187 | |
| 188 | return ret; |
| 189 | } |
| 190 | |
| 191 | /* continue trying to read len bytes - don't return until len |
| 192 | has been read */ |
| 193 | static void read_loop(int fd, char *buf, int len) |
| 194 | { |
| 195 | while (len) { |
| 196 | int n = read_timeout(fd, buf, len); |
| 197 | |
| 198 | buf += n; |
| 199 | len -= n; |
| 200 | } |
| 201 | } |
| 202 | |
| 203 | /* read from the file descriptor handling multiplexing - |
| 204 | return number of bytes read |
| 205 | never return <= 0 */ |
| 206 | static int read_unbuffered(int fd, char *buf, int len) |
| 207 | { |
| 208 | static int remaining; |
| 209 | int tag, ret=0; |
| 210 | char line[1024]; |
| 211 | |
| 212 | if (!io_multiplexing_in || fd != multiplex_in_fd) |
| 213 | return read_timeout(fd, buf, len); |
| 214 | |
| 215 | while (ret == 0) { |
| 216 | if (remaining) { |
| 217 | len = MIN(len, remaining); |
| 218 | read_loop(fd, buf, len); |
| 219 | remaining -= len; |
| 220 | ret = len; |
| 221 | continue; |
| 222 | } |
| 223 | |
| 224 | read_loop(fd, line, 4); |
| 225 | tag = IVAL(line, 0); |
| 226 | |
| 227 | remaining = tag & 0xFFFFFF; |
| 228 | tag = tag >> 24; |
| 229 | |
| 230 | if (tag == MPLEX_BASE) continue; |
| 231 | |
| 232 | tag -= MPLEX_BASE; |
| 233 | |
| 234 | if (tag != FERROR && tag != FINFO) { |
| 235 | rprintf(FERROR,"unexpected tag %d\n", tag); |
| 236 | exit_cleanup(RERR_STREAMIO); |
| 237 | } |
| 238 | |
| 239 | if (remaining > sizeof(line)-1) { |
| 240 | rprintf(FERROR,"multiplexing overflow %d\n\n", |
| 241 | remaining); |
| 242 | exit_cleanup(RERR_STREAMIO); |
| 243 | } |
| 244 | |
| 245 | read_loop(fd, line, remaining); |
| 246 | line[remaining] = 0; |
| 247 | |
| 248 | rprintf((enum logcode)tag,"%s", line); |
| 249 | remaining = 0; |
| 250 | } |
| 251 | |
| 252 | return ret; |
| 253 | } |
| 254 | |
| 255 | |
| 256 | /* do a buffered read from fd. don't return until all N bytes |
| 257 | have been read. If all N can't be read then exit with an error */ |
| 258 | static void readfd(int fd,char *buffer,int N) |
| 259 | { |
| 260 | int ret; |
| 261 | int total=0; |
| 262 | |
| 263 | while (total < N) { |
| 264 | io_flush(); |
| 265 | |
| 266 | ret = read_unbuffered(fd,buffer + total,N-total); |
| 267 | total += ret; |
| 268 | } |
| 269 | |
| 270 | stats.total_read += total; |
| 271 | } |
| 272 | |
| 273 | |
| 274 | int32 read_int(int f) |
| 275 | { |
| 276 | char b[4]; |
| 277 | int32 ret; |
| 278 | |
| 279 | readfd(f,b,4); |
| 280 | ret = IVAL(b,0); |
| 281 | if (ret == (int32)0xffffffff) return -1; |
| 282 | return ret; |
| 283 | } |
| 284 | |
| 285 | int64 read_longint(int f) |
| 286 | { |
| 287 | extern int remote_version; |
| 288 | int64 ret; |
| 289 | char b[8]; |
| 290 | ret = read_int(f); |
| 291 | |
| 292 | if ((int32)ret != (int32)0xffffffff) { |
| 293 | return ret; |
| 294 | } |
| 295 | |
| 296 | #ifdef NO_INT64 |
| 297 | rprintf(FERROR,"Integer overflow - attempted 64 bit offset\n"); |
| 298 | exit_cleanup(RERR_UNSUPPORTED); |
| 299 | #else |
| 300 | if (remote_version >= 16) { |
| 301 | readfd(f,b,8); |
| 302 | ret = IVAL(b,0) | (((int64)IVAL(b,4))<<32); |
| 303 | } |
| 304 | #endif |
| 305 | |
| 306 | return ret; |
| 307 | } |
| 308 | |
| 309 | void read_buf(int f,char *buf,int len) |
| 310 | { |
| 311 | readfd(f,buf,len); |
| 312 | } |
| 313 | |
| 314 | void read_sbuf(int f,char *buf,int len) |
| 315 | { |
| 316 | read_buf(f,buf,len); |
| 317 | buf[len] = 0; |
| 318 | } |
| 319 | |
| 320 | unsigned char read_byte(int f) |
| 321 | { |
| 322 | unsigned char c; |
| 323 | read_buf(f,(char *)&c,1); |
| 324 | return c; |
| 325 | } |
| 326 | |
| 327 | /* write len bytes to fd */ |
| 328 | static void writefd_unbuffered(int fd,char *buf,int len) |
| 329 | { |
| 330 | int total = 0; |
| 331 | fd_set w_fds, r_fds; |
| 332 | int fd_count, count; |
| 333 | struct timeval tv; |
| 334 | |
| 335 | no_flush++; |
| 336 | |
| 337 | while (total < len) { |
| 338 | FD_ZERO(&w_fds); |
| 339 | FD_ZERO(&r_fds); |
| 340 | FD_SET(fd,&w_fds); |
| 341 | fd_count = fd; |
| 342 | |
| 343 | if (io_error_fd != -1) { |
| 344 | FD_SET(io_error_fd,&r_fds); |
| 345 | if (io_error_fd > fd_count) |
| 346 | fd_count = io_error_fd; |
| 347 | } |
| 348 | |
| 349 | tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT; |
| 350 | tv.tv_usec = 0; |
| 351 | |
| 352 | errno = 0; |
| 353 | |
| 354 | count = select(fd_count+1, |
| 355 | io_error_fd != -1?&r_fds:NULL, |
| 356 | &w_fds,NULL, |
| 357 | &tv); |
| 358 | |
| 359 | if (count <= 0) { |
| 360 | if (errno == EBADF) { |
| 361 | exit_cleanup(RERR_SOCKETIO); |
| 362 | } |
| 363 | check_timeout(); |
| 364 | continue; |
| 365 | } |
| 366 | |
| 367 | if (io_error_fd != -1 && FD_ISSET(io_error_fd, &r_fds)) { |
| 368 | read_error_fd(); |
| 369 | } |
| 370 | |
| 371 | if (FD_ISSET(fd, &w_fds)) { |
| 372 | int ret, n = len-total; |
| 373 | |
| 374 | ret = write(fd,buf+total,n); |
| 375 | |
| 376 | if (ret == -1 && errno == EINTR) { |
| 377 | continue; |
| 378 | } |
| 379 | |
| 380 | if (ret == -1 && |
| 381 | (errno == EWOULDBLOCK || errno == EAGAIN)) { |
| 382 | msleep(1); |
| 383 | continue; |
| 384 | } |
| 385 | |
| 386 | if (ret <= 0) { |
| 387 | rprintf(FERROR, |
| 388 | "error writing %d unbuffered bytes" |
| 389 | " - exiting: %s\n", len, |
| 390 | strerror(errno)); |
| 391 | exit_cleanup(RERR_STREAMIO); |
| 392 | } |
| 393 | |
| 394 | /* Sleep after writing to limit I/O bandwidth */ |
| 395 | if (bwlimit) |
| 396 | { |
| 397 | tv.tv_sec = 0; |
| 398 | tv.tv_usec = ret * 1000 / bwlimit; |
| 399 | while (tv.tv_usec > 1000000) |
| 400 | { |
| 401 | tv.tv_sec++; |
| 402 | tv.tv_usec -= 1000000; |
| 403 | } |
| 404 | select(0, NULL, NULL, NULL, &tv); |
| 405 | } |
| 406 | |
| 407 | total += ret; |
| 408 | |
| 409 | if (io_timeout) |
| 410 | last_io = time(NULL); |
| 411 | } |
| 412 | } |
| 413 | |
| 414 | no_flush--; |
| 415 | } |
| 416 | |
| 417 | |
| 418 | static char *io_buffer; |
| 419 | static int io_buffer_count; |
| 420 | |
| 421 | void io_start_buffering(int fd) |
| 422 | { |
| 423 | if (io_buffer) return; |
| 424 | multiplex_out_fd = fd; |
| 425 | io_buffer = (char *)malloc(IO_BUFFER_SIZE); |
| 426 | if (!io_buffer) out_of_memory("writefd"); |
| 427 | io_buffer_count = 0; |
| 428 | } |
| 429 | |
| 430 | /* write an message to a multiplexed stream. If this fails then rsync |
| 431 | exits */ |
| 432 | static void mplex_write(int fd, enum logcode code, char *buf, int len) |
| 433 | { |
| 434 | char buffer[4096]; |
| 435 | int n = len; |
| 436 | |
| 437 | SIVAL(buffer, 0, ((MPLEX_BASE + (int)code)<<24) + len); |
| 438 | |
| 439 | if (n > (sizeof(buffer)-4)) { |
| 440 | n = sizeof(buffer)-4; |
| 441 | } |
| 442 | |
| 443 | memcpy(&buffer[4], buf, n); |
| 444 | writefd_unbuffered(fd, buffer, n+4); |
| 445 | |
| 446 | len -= n; |
| 447 | buf += n; |
| 448 | |
| 449 | if (len) { |
| 450 | writefd_unbuffered(fd, buf, len); |
| 451 | } |
| 452 | } |
| 453 | |
| 454 | |
| 455 | void io_flush(void) |
| 456 | { |
| 457 | int fd = multiplex_out_fd; |
| 458 | if (!io_buffer_count || no_flush) return; |
| 459 | |
| 460 | if (io_multiplexing_out) { |
| 461 | mplex_write(fd, FNONE, io_buffer, io_buffer_count); |
| 462 | } else { |
| 463 | writefd_unbuffered(fd, io_buffer, io_buffer_count); |
| 464 | } |
| 465 | io_buffer_count = 0; |
| 466 | } |
| 467 | |
| 468 | |
| 469 | /* XXX: fd is ignored, which seems a little strange. */ |
| 470 | void io_end_buffering(int fd) |
| 471 | { |
| 472 | io_flush(); |
| 473 | if (!io_multiplexing_out) { |
| 474 | free(io_buffer); |
| 475 | io_buffer = NULL; |
| 476 | } |
| 477 | } |
| 478 | |
| 479 | /* some OSes have a bug where an exit causes the pending writes on |
| 480 | a socket to be flushed. Do an explicit shutdown to try to prevent this */ |
| 481 | void io_shutdown(void) |
| 482 | { |
| 483 | if (multiplex_out_fd != -1) close(multiplex_out_fd); |
| 484 | if (io_error_fd != -1) close(io_error_fd); |
| 485 | multiplex_out_fd = -1; |
| 486 | io_error_fd = -1; |
| 487 | } |
| 488 | |
| 489 | |
| 490 | static void writefd(int fd,char *buf,int len) |
| 491 | { |
| 492 | stats.total_written += len; |
| 493 | |
| 494 | if (!io_buffer || fd != multiplex_out_fd) { |
| 495 | writefd_unbuffered(fd, buf, len); |
| 496 | return; |
| 497 | } |
| 498 | |
| 499 | while (len) { |
| 500 | int n = MIN(len, IO_BUFFER_SIZE-io_buffer_count); |
| 501 | if (n > 0) { |
| 502 | memcpy(io_buffer+io_buffer_count, buf, n); |
| 503 | buf += n; |
| 504 | len -= n; |
| 505 | io_buffer_count += n; |
| 506 | } |
| 507 | |
| 508 | if (io_buffer_count == IO_BUFFER_SIZE) io_flush(); |
| 509 | } |
| 510 | } |
| 511 | |
| 512 | |
| 513 | void write_int(int f,int32 x) |
| 514 | { |
| 515 | char b[4]; |
| 516 | SIVAL(b,0,x); |
| 517 | writefd(f,b,4); |
| 518 | } |
| 519 | |
| 520 | |
| 521 | /* |
| 522 | * Note: int64 may actually be a 32-bit type if ./configure couldn't find any |
| 523 | * 64-bit types on this platform. |
| 524 | */ |
| 525 | void write_longint(int f, int64 x) |
| 526 | { |
| 527 | extern int remote_version; |
| 528 | char b[8]; |
| 529 | |
| 530 | if (remote_version < 16 || x <= 0x7FFFFFFF) { |
| 531 | write_int(f, (int)x); |
| 532 | return; |
| 533 | } |
| 534 | |
| 535 | write_int(f, (int32)0xFFFFFFFF); |
| 536 | SIVAL(b,0,(x&0xFFFFFFFF)); |
| 537 | SIVAL(b,4,((x>>32)&0xFFFFFFFF)); |
| 538 | |
| 539 | writefd(f,b,8); |
| 540 | } |
| 541 | |
| 542 | void write_buf(int f,char *buf,int len) |
| 543 | { |
| 544 | writefd(f,buf,len); |
| 545 | } |
| 546 | |
| 547 | /* write a string to the connection */ |
| 548 | static void write_sbuf(int f,char *buf) |
| 549 | { |
| 550 | write_buf(f, buf, strlen(buf)); |
| 551 | } |
| 552 | |
| 553 | |
| 554 | void write_byte(int f,unsigned char c) |
| 555 | { |
| 556 | write_buf(f,(char *)&c,1); |
| 557 | } |
| 558 | |
| 559 | int read_line(int f, char *buf, int maxlen) |
| 560 | { |
| 561 | eof_error = 0; |
| 562 | |
| 563 | while (maxlen) { |
| 564 | buf[0] = 0; |
| 565 | read_buf(f, buf, 1); |
| 566 | if (buf[0] == 0) return 0; |
| 567 | if (buf[0] == '\n') { |
| 568 | buf[0] = 0; |
| 569 | break; |
| 570 | } |
| 571 | if (buf[0] != '\r') { |
| 572 | buf++; |
| 573 | maxlen--; |
| 574 | } |
| 575 | } |
| 576 | if (maxlen == 0) { |
| 577 | *buf = 0; |
| 578 | return 0; |
| 579 | } |
| 580 | |
| 581 | eof_error = 1; |
| 582 | |
| 583 | return 1; |
| 584 | } |
| 585 | |
| 586 | |
| 587 | void io_printf(int fd, const char *format, ...) |
| 588 | { |
| 589 | va_list ap; |
| 590 | char buf[1024]; |
| 591 | int len; |
| 592 | |
| 593 | va_start(ap, format); |
| 594 | len = vslprintf(buf, sizeof(buf), format, ap); |
| 595 | va_end(ap); |
| 596 | |
| 597 | if (len < 0) exit_cleanup(RERR_STREAMIO); |
| 598 | |
| 599 | write_sbuf(fd, buf); |
| 600 | } |
| 601 | |
| 602 | |
| 603 | /* setup for multiplexing an error stream with the data stream */ |
| 604 | void io_start_multiplex_out(int fd) |
| 605 | { |
| 606 | multiplex_out_fd = fd; |
| 607 | io_flush(); |
| 608 | io_start_buffering(fd); |
| 609 | io_multiplexing_out = 1; |
| 610 | } |
| 611 | |
| 612 | /* setup for multiplexing an error stream with the data stream */ |
| 613 | void io_start_multiplex_in(int fd) |
| 614 | { |
| 615 | multiplex_in_fd = fd; |
| 616 | io_flush(); |
| 617 | io_multiplexing_in = 1; |
| 618 | } |
| 619 | |
| 620 | /* write an message to the multiplexed error stream */ |
| 621 | int io_multiplex_write(enum logcode code, char *buf, int len) |
| 622 | { |
| 623 | if (!io_multiplexing_out) return 0; |
| 624 | |
| 625 | io_flush(); |
| 626 | stats.total_written += (len+4); |
| 627 | mplex_write(multiplex_out_fd, code, buf, len); |
| 628 | return 1; |
| 629 | } |
| 630 | |
| 631 | /* write a message to the special error fd */ |
| 632 | int io_error_write(int f, enum logcode code, char *buf, int len) |
| 633 | { |
| 634 | if (f == -1) return 0; |
| 635 | mplex_write(f, code, buf, len); |
| 636 | return 1; |
| 637 | } |
| 638 | |
| 639 | /* stop output multiplexing */ |
| 640 | void io_multiplexing_close(void) |
| 641 | { |
| 642 | io_multiplexing_out = 0; |
| 643 | } |
| 644 | |