| 1 | /* |
| 2 | Copyright (C) Andrew Tridgell 1996 |
| 3 | Copyright (C) Paul Mackerras 1996 |
| 4 | |
| 5 | This program is free software; you can redistribute it and/or modify |
| 6 | it under the terms of the GNU General Public License as published by |
| 7 | the Free Software Foundation; either version 2 of the License, or |
| 8 | (at your option) any later version. |
| 9 | |
| 10 | This program is distributed in the hope that it will be useful, |
| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | GNU General Public License for more details. |
| 14 | |
| 15 | You should have received a copy of the GNU General Public License |
| 16 | along with this program; if not, write to the Free Software |
| 17 | Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 18 | */ |
| 19 | |
| 20 | /* |
| 21 | Utilities used in rsync |
| 22 | |
| 23 | tridge, June 1996 |
| 24 | */ |
| 25 | #include "rsync.h" |
| 26 | |
| 27 | /* if no timeout is specified then use a 60 second select timeout */ |
| 28 | #define SELECT_TIMEOUT 60 |
| 29 | |
| 30 | static int io_multiplexing_out; |
| 31 | static int io_multiplexing_in; |
| 32 | static int multiplex_in_fd; |
| 33 | static int multiplex_out_fd; |
| 34 | static time_t last_io; |
| 35 | static int eof_error=1; |
| 36 | extern int verbose; |
| 37 | extern int io_timeout; |
| 38 | extern struct stats stats; |
| 39 | |
| 40 | static int buffer_f_in = -1; |
| 41 | |
| 42 | void setup_readbuffer(int f_in) |
| 43 | { |
| 44 | buffer_f_in = f_in; |
| 45 | } |
| 46 | |
| 47 | static void check_timeout(void) |
| 48 | { |
| 49 | time_t t; |
| 50 | |
| 51 | if (!io_timeout) return; |
| 52 | |
| 53 | if (!last_io) { |
| 54 | last_io = time(NULL); |
| 55 | return; |
| 56 | } |
| 57 | |
| 58 | t = time(NULL); |
| 59 | |
| 60 | if (last_io && io_timeout && (t-last_io) >= io_timeout) { |
| 61 | rprintf(FERROR,"io timeout after %d second - exiting\n", |
| 62 | (int)(t-last_io)); |
| 63 | exit_cleanup(1); |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | |
| 68 | static char *read_buffer; |
| 69 | static char *read_buffer_p; |
| 70 | static int read_buffer_len; |
| 71 | static int read_buffer_size; |
| 72 | static int no_flush; |
| 73 | static int no_flush_read; |
| 74 | |
| 75 | /* read from a socket with IO timeout. return the number of |
| 76 | bytes read. If no bytes can be read then exit, never return |
| 77 | a number <= 0 */ |
| 78 | static int read_timeout(int fd, char *buf, int len) |
| 79 | { |
| 80 | int n, ret=0; |
| 81 | |
| 82 | no_flush_read++; |
| 83 | io_flush(); |
| 84 | no_flush_read--; |
| 85 | |
| 86 | while (ret == 0) { |
| 87 | fd_set fds; |
| 88 | struct timeval tv; |
| 89 | |
| 90 | FD_ZERO(&fds); |
| 91 | FD_SET(fd, &fds); |
| 92 | tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT; |
| 93 | tv.tv_usec = 0; |
| 94 | |
| 95 | if (select(fd+1, &fds, NULL, NULL, &tv) != 1) { |
| 96 | check_timeout(); |
| 97 | continue; |
| 98 | } |
| 99 | |
| 100 | n = read(fd, buf, len); |
| 101 | |
| 102 | if (n > 0) { |
| 103 | stats.total_read += n; |
| 104 | buf += n; |
| 105 | len -= n; |
| 106 | ret += n; |
| 107 | if (io_timeout) |
| 108 | last_io = time(NULL); |
| 109 | continue; |
| 110 | } |
| 111 | |
| 112 | if (n == -1 && errno == EINTR) { |
| 113 | continue; |
| 114 | } |
| 115 | |
| 116 | if (n == -1 && |
| 117 | (errno == EAGAIN || errno == EWOULDBLOCK)) { |
| 118 | /* this shouldn't happen, if it does then |
| 119 | sleep for a short time to prevent us |
| 120 | chewing too much CPU */ |
| 121 | u_sleep(100); |
| 122 | continue; |
| 123 | } |
| 124 | |
| 125 | if (n == 0) { |
| 126 | if (eof_error) { |
| 127 | rprintf(FERROR,"unexpected EOF in read_timeout\n"); |
| 128 | } |
| 129 | exit_cleanup(1); |
| 130 | } |
| 131 | |
| 132 | rprintf(FERROR,"read error: %s\n", strerror(errno)); |
| 133 | exit_cleanup(1); |
| 134 | } |
| 135 | |
| 136 | return ret; |
| 137 | } |
| 138 | |
| 139 | /* continue trying to read len bytes - don't return until len |
| 140 | has been read */ |
| 141 | static void read_loop(int fd, char *buf, int len) |
| 142 | { |
| 143 | while (len) { |
| 144 | int n = read_timeout(fd, buf, len); |
| 145 | |
| 146 | buf += n; |
| 147 | len -= n; |
| 148 | } |
| 149 | } |
| 150 | |
| 151 | /* read from the file descriptor handling multiplexing - |
| 152 | return number of bytes read |
| 153 | never return <= 0 */ |
| 154 | static int read_unbuffered(int fd, char *buf, int len) |
| 155 | { |
| 156 | static int remaining; |
| 157 | char ibuf[4]; |
| 158 | int tag, ret=0; |
| 159 | char line[1024]; |
| 160 | |
| 161 | if (!io_multiplexing_in || fd != multiplex_in_fd) |
| 162 | return read_timeout(fd, buf, len); |
| 163 | |
| 164 | while (ret == 0) { |
| 165 | if (remaining) { |
| 166 | len = MIN(len, remaining); |
| 167 | read_loop(fd, buf, len); |
| 168 | remaining -= len; |
| 169 | ret = len; |
| 170 | continue; |
| 171 | } |
| 172 | |
| 173 | read_loop(fd, ibuf, 4); |
| 174 | tag = IVAL(ibuf, 0); |
| 175 | |
| 176 | remaining = tag & 0xFFFFFF; |
| 177 | tag = tag >> 24; |
| 178 | |
| 179 | if (tag == MPLEX_BASE) continue; |
| 180 | |
| 181 | tag -= MPLEX_BASE; |
| 182 | |
| 183 | if (tag != FERROR && tag != FINFO) { |
| 184 | rprintf(FERROR,"unexpected tag %d\n", tag); |
| 185 | exit_cleanup(1); |
| 186 | } |
| 187 | |
| 188 | if (remaining > sizeof(line)-1) { |
| 189 | rprintf(FERROR,"multiplexing overflow %d\n\n", |
| 190 | remaining); |
| 191 | exit_cleanup(1); |
| 192 | } |
| 193 | |
| 194 | read_loop(fd, line, remaining); |
| 195 | line[remaining] = 0; |
| 196 | |
| 197 | rprintf(tag,"%s", line); |
| 198 | remaining = 0; |
| 199 | } |
| 200 | |
| 201 | return ret; |
| 202 | } |
| 203 | |
| 204 | |
| 205 | |
| 206 | /* This function was added to overcome a deadlock problem when using |
| 207 | * ssh. It looks like we can't allow our receive queue to get full or |
| 208 | * ssh will clag up. Uggh. */ |
| 209 | static void read_check(int f) |
| 210 | { |
| 211 | int n = 8192; |
| 212 | |
| 213 | if (f == -1) return; |
| 214 | |
| 215 | if (read_buffer_len == 0) { |
| 216 | read_buffer_p = read_buffer; |
| 217 | } |
| 218 | |
| 219 | if (n > MAX_READ_BUFFER/4) |
| 220 | n = MAX_READ_BUFFER/4; |
| 221 | |
| 222 | if (read_buffer_p != read_buffer) { |
| 223 | memmove(read_buffer,read_buffer_p,read_buffer_len); |
| 224 | read_buffer_p = read_buffer; |
| 225 | } |
| 226 | |
| 227 | if (n > (read_buffer_size - read_buffer_len)) { |
| 228 | read_buffer_size += n; |
| 229 | read_buffer = (char *)Realloc(read_buffer,read_buffer_size); |
| 230 | if (!read_buffer) out_of_memory("read check"); |
| 231 | read_buffer_p = read_buffer; |
| 232 | } |
| 233 | |
| 234 | n = read_unbuffered(f,read_buffer+read_buffer_len,n); |
| 235 | read_buffer_len += n; |
| 236 | } |
| 237 | |
| 238 | |
| 239 | /* do a buffered read from fd. don't return until all N bytes |
| 240 | have been read. If all N can't be read then exit with an error */ |
| 241 | static void readfd(int fd,char *buffer,int N) |
| 242 | { |
| 243 | int ret; |
| 244 | int total=0; |
| 245 | |
| 246 | if ((read_buffer_len < N) && (N < 1024)) { |
| 247 | read_check(buffer_f_in); |
| 248 | } |
| 249 | |
| 250 | while (total < N) { |
| 251 | if (read_buffer_len > 0 && buffer_f_in == fd) { |
| 252 | ret = MIN(read_buffer_len,N-total); |
| 253 | memcpy(buffer+total,read_buffer_p,ret); |
| 254 | read_buffer_p += ret; |
| 255 | read_buffer_len -= ret; |
| 256 | total += ret; |
| 257 | continue; |
| 258 | } |
| 259 | |
| 260 | no_flush_read++; |
| 261 | io_flush(); |
| 262 | no_flush_read--; |
| 263 | |
| 264 | ret = read_unbuffered(fd,buffer + total,N-total); |
| 265 | total += ret; |
| 266 | } |
| 267 | } |
| 268 | |
| 269 | |
| 270 | int32 read_int(int f) |
| 271 | { |
| 272 | char b[4]; |
| 273 | readfd(f,b,4); |
| 274 | return IVAL(b,0); |
| 275 | } |
| 276 | |
| 277 | int64 read_longint(int f) |
| 278 | { |
| 279 | extern int remote_version; |
| 280 | int64 ret; |
| 281 | char b[8]; |
| 282 | ret = read_int(f); |
| 283 | |
| 284 | if ((int32)ret != (int32)0xffffffff) return ret; |
| 285 | |
| 286 | #ifdef NO_INT64 |
| 287 | rprintf(FERROR,"Integer overflow - attempted 64 bit offset\n"); |
| 288 | exit_cleanup(1); |
| 289 | #else |
| 290 | if (remote_version >= 16) { |
| 291 | readfd(f,b,8); |
| 292 | ret = IVAL(b,0) | (((int64)IVAL(b,4))<<32); |
| 293 | } |
| 294 | #endif |
| 295 | |
| 296 | return ret; |
| 297 | } |
| 298 | |
| 299 | void read_buf(int f,char *buf,int len) |
| 300 | { |
| 301 | readfd(f,buf,len); |
| 302 | } |
| 303 | |
| 304 | void read_sbuf(int f,char *buf,int len) |
| 305 | { |
| 306 | read_buf(f,buf,len); |
| 307 | buf[len] = 0; |
| 308 | } |
| 309 | |
| 310 | unsigned char read_byte(int f) |
| 311 | { |
| 312 | unsigned char c; |
| 313 | read_buf(f,(char *)&c,1); |
| 314 | return c; |
| 315 | } |
| 316 | |
| 317 | |
| 318 | |
| 319 | /* write len bytes to fd, possibly reading from buffer_f_in if set |
| 320 | in order to unclog the pipe. don't return until all len |
| 321 | bytes have been written */ |
| 322 | static void writefd_unbuffered(int fd,char *buf,int len) |
| 323 | { |
| 324 | int total = 0; |
| 325 | fd_set w_fds, r_fds; |
| 326 | int fd_count, count; |
| 327 | struct timeval tv; |
| 328 | int reading=0; |
| 329 | int blocked=0; |
| 330 | |
| 331 | no_flush++; |
| 332 | |
| 333 | while (total < len) { |
| 334 | FD_ZERO(&w_fds); |
| 335 | FD_ZERO(&r_fds); |
| 336 | FD_SET(fd,&w_fds); |
| 337 | fd_count = fd+1; |
| 338 | |
| 339 | if (!no_flush_read) { |
| 340 | reading = (buffer_f_in != -1); |
| 341 | } |
| 342 | |
| 343 | if (reading) { |
| 344 | FD_SET(buffer_f_in,&r_fds); |
| 345 | if (buffer_f_in > fd) |
| 346 | fd_count = buffer_f_in+1; |
| 347 | } |
| 348 | |
| 349 | tv.tv_sec = io_timeout?io_timeout:SELECT_TIMEOUT; |
| 350 | tv.tv_usec = 0; |
| 351 | |
| 352 | count = select(fd_count, |
| 353 | reading?&r_fds:NULL, |
| 354 | &w_fds,NULL, |
| 355 | &tv); |
| 356 | |
| 357 | if (count <= 0) { |
| 358 | check_timeout(); |
| 359 | continue; |
| 360 | } |
| 361 | |
| 362 | if (reading && FD_ISSET(buffer_f_in, &r_fds)) { |
| 363 | read_check(buffer_f_in); |
| 364 | } |
| 365 | |
| 366 | if (FD_ISSET(fd, &w_fds)) { |
| 367 | int n = (len-total)>>blocked; |
| 368 | int ret = write(fd,buf+total,n?n:1); |
| 369 | |
| 370 | if (ret == -1 && errno == EINTR) { |
| 371 | continue; |
| 372 | } |
| 373 | |
| 374 | if (ret == -1 && |
| 375 | (errno == EAGAIN || errno == EWOULDBLOCK)) { |
| 376 | blocked++; |
| 377 | continue; |
| 378 | } |
| 379 | |
| 380 | if (ret <= 0) { |
| 381 | rprintf(FERROR,"erroring writing %d bytes - exiting\n", len); |
| 382 | exit_cleanup(1); |
| 383 | } |
| 384 | |
| 385 | blocked = 0; |
| 386 | total += ret; |
| 387 | stats.total_written += ret; |
| 388 | |
| 389 | if (io_timeout) |
| 390 | last_io = time(NULL); |
| 391 | } |
| 392 | } |
| 393 | |
| 394 | no_flush--; |
| 395 | } |
| 396 | |
| 397 | |
| 398 | static char *io_buffer; |
| 399 | static int io_buffer_count; |
| 400 | |
| 401 | void io_start_buffering(int fd) |
| 402 | { |
| 403 | if (io_buffer) return; |
| 404 | multiplex_out_fd = fd; |
| 405 | io_buffer = (char *)malloc(IO_BUFFER_SIZE+4); |
| 406 | if (!io_buffer) out_of_memory("writefd"); |
| 407 | io_buffer_count = 0; |
| 408 | |
| 409 | /* leave room for the multiplex header in case it's needed */ |
| 410 | io_buffer += 4; |
| 411 | } |
| 412 | |
| 413 | void io_flush(void) |
| 414 | { |
| 415 | int fd = multiplex_out_fd; |
| 416 | if (!io_buffer_count || no_flush) return; |
| 417 | |
| 418 | if (io_multiplexing_out) { |
| 419 | SIVAL(io_buffer-4, 0, (MPLEX_BASE<<24) + io_buffer_count); |
| 420 | writefd_unbuffered(fd, io_buffer-4, io_buffer_count+4); |
| 421 | } else { |
| 422 | writefd_unbuffered(fd, io_buffer, io_buffer_count); |
| 423 | } |
| 424 | io_buffer_count = 0; |
| 425 | } |
| 426 | |
| 427 | void io_end_buffering(int fd) |
| 428 | { |
| 429 | io_flush(); |
| 430 | if (!io_multiplexing_out) { |
| 431 | free(io_buffer-4); |
| 432 | io_buffer = NULL; |
| 433 | } |
| 434 | } |
| 435 | |
| 436 | static void writefd(int fd,char *buf,int len) |
| 437 | { |
| 438 | if (!io_buffer) { |
| 439 | writefd_unbuffered(fd, buf, len); |
| 440 | return; |
| 441 | } |
| 442 | |
| 443 | while (len) { |
| 444 | int n = MIN(len, IO_BUFFER_SIZE-io_buffer_count); |
| 445 | if (n > 0) { |
| 446 | memcpy(io_buffer+io_buffer_count, buf, n); |
| 447 | buf += n; |
| 448 | len -= n; |
| 449 | io_buffer_count += n; |
| 450 | } |
| 451 | |
| 452 | if (io_buffer_count == IO_BUFFER_SIZE) io_flush(); |
| 453 | } |
| 454 | } |
| 455 | |
| 456 | |
| 457 | void write_int(int f,int32 x) |
| 458 | { |
| 459 | char b[4]; |
| 460 | SIVAL(b,0,x); |
| 461 | writefd(f,b,4); |
| 462 | } |
| 463 | |
| 464 | void write_longint(int f, int64 x) |
| 465 | { |
| 466 | extern int remote_version; |
| 467 | char b[8]; |
| 468 | |
| 469 | if (remote_version < 16 || x <= 0x7FFFFFFF) { |
| 470 | write_int(f, (int)x); |
| 471 | return; |
| 472 | } |
| 473 | |
| 474 | write_int(f, -1); |
| 475 | SIVAL(b,0,(x&0xFFFFFFFF)); |
| 476 | SIVAL(b,4,((x>>32)&0xFFFFFFFF)); |
| 477 | |
| 478 | writefd(f,b,8); |
| 479 | } |
| 480 | |
| 481 | void write_buf(int f,char *buf,int len) |
| 482 | { |
| 483 | writefd(f,buf,len); |
| 484 | } |
| 485 | |
| 486 | /* write a string to the connection */ |
| 487 | static void write_sbuf(int f,char *buf) |
| 488 | { |
| 489 | write_buf(f, buf, strlen(buf)); |
| 490 | } |
| 491 | |
| 492 | |
| 493 | void write_byte(int f,unsigned char c) |
| 494 | { |
| 495 | write_buf(f,(char *)&c,1); |
| 496 | } |
| 497 | |
| 498 | int read_line(int f, char *buf, int maxlen) |
| 499 | { |
| 500 | eof_error = 0; |
| 501 | |
| 502 | while (maxlen) { |
| 503 | buf[0] = 0; |
| 504 | read_buf(f, buf, 1); |
| 505 | if (buf[0] == 0) return 0; |
| 506 | if (buf[0] == '\n') { |
| 507 | buf[0] = 0; |
| 508 | break; |
| 509 | } |
| 510 | if (buf[0] != '\r') { |
| 511 | buf++; |
| 512 | maxlen--; |
| 513 | } |
| 514 | } |
| 515 | if (maxlen == 0) { |
| 516 | *buf = 0; |
| 517 | return 0; |
| 518 | } |
| 519 | |
| 520 | eof_error = 1; |
| 521 | |
| 522 | return 1; |
| 523 | } |
| 524 | |
| 525 | |
| 526 | void io_printf(int fd, const char *format, ...) |
| 527 | { |
| 528 | va_list ap; |
| 529 | char buf[1024]; |
| 530 | int len; |
| 531 | |
| 532 | va_start(ap, format); |
| 533 | len = vslprintf(buf, sizeof(buf)-1, format, ap); |
| 534 | va_end(ap); |
| 535 | |
| 536 | if (len < 0) exit_cleanup(1); |
| 537 | |
| 538 | write_sbuf(fd, buf); |
| 539 | } |
| 540 | |
| 541 | |
| 542 | /* setup for multiplexing an error stream with the data stream */ |
| 543 | void io_start_multiplex_out(int fd) |
| 544 | { |
| 545 | multiplex_out_fd = fd; |
| 546 | io_flush(); |
| 547 | io_start_buffering(fd); |
| 548 | io_multiplexing_out = 1; |
| 549 | } |
| 550 | |
| 551 | /* setup for multiplexing an error stream with the data stream */ |
| 552 | void io_start_multiplex_in(int fd) |
| 553 | { |
| 554 | multiplex_in_fd = fd; |
| 555 | io_flush(); |
| 556 | if (read_buffer_len) { |
| 557 | fprintf(stderr,"ERROR: data in read buffer at mplx start\n"); |
| 558 | exit_cleanup(1); |
| 559 | } |
| 560 | |
| 561 | io_multiplexing_in = 1; |
| 562 | } |
| 563 | |
| 564 | /* write an message to the error stream */ |
| 565 | int io_multiplex_write(int f, char *buf, int len) |
| 566 | { |
| 567 | if (!io_multiplexing_out) return 0; |
| 568 | |
| 569 | io_flush(); |
| 570 | |
| 571 | SIVAL(io_buffer-4, 0, ((MPLEX_BASE + f)<<24) + len); |
| 572 | memcpy(io_buffer, buf, len); |
| 573 | |
| 574 | writefd_unbuffered(multiplex_out_fd, io_buffer-4, len+4); |
| 575 | return 1; |
| 576 | } |
| 577 | |
| 578 | void io_close_input(int fd) |
| 579 | { |
| 580 | buffer_f_in = -1; |
| 581 | } |