io.c

   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 static int64 total_written;
  28 static int64 total_read;
  29
  30 extern int verbose;
  31 extern int sparse_files;
  32 extern int io_timeout;
  33
  34 int64 write_total(void)
  35 {
  36   return total_written;
  37 }
  38
  39 int64 read_total(void)
  40 {
  41   return total_read;
  42 }
  43
  44 static int buffer_f_in = -1;
  45
  46 void setup_nonblocking(int f_in,int f_out)
  47 {
  48         set_blocking(f_out,0);
  49         buffer_f_in = f_in;
  50 }
  51
  52
  53 static char *read_buffer;
  54 static char *read_buffer_p;
  55 static int read_buffer_len;
  56 static int read_buffer_size;
  57
  58
  59 /* This function was added to overcome a deadlock problem when using
  60  * ssh.  It looks like we can't allow our receive queue to get full or
  61  * ssh will clag up. Uggh.  */
  62 static void read_check(int f)
  63 {
  64         int n;
  65
  66         if (f == -1) return;
  67
  68         if (read_buffer_len == 0) {
  69                 read_buffer_p = read_buffer;
  70         }
  71
  72         if ((n=num_waiting(f)) <= 0)
  73                 return;
  74
  75         /* things could deteriorate if we read in really small chunks */
  76         if (n < 10) n = 1024;
  77
  78         if (n > MAX_READ_BUFFER/4)
  79                 n = MAX_READ_BUFFER/4;
  80
  81         if (read_buffer_p != read_buffer) {
  82                 memmove(read_buffer,read_buffer_p,read_buffer_len);
  83                 read_buffer_p = read_buffer;
  84         }
  85
  86         if (n > (read_buffer_size - read_buffer_len)) {
  87                 read_buffer_size += n;
  88                 if (!read_buffer)
  89                         read_buffer = (char *)malloc(read_buffer_size);
  90                 else
  91                         read_buffer = (char *)realloc(read_buffer,read_buffer_size);
  92                 if (!read_buffer) out_of_memory("read check");
  93                 read_buffer_p = read_buffer;
  94         }
  95
  96         n = read(f,read_buffer+read_buffer_len,n);
  97         if (n > 0) {
  98                 read_buffer_len += n;
  99         }
 100 }
 101
 102 static time_t last_io;
 103
 104
 105 static void check_timeout(void)
 106 {
 107         time_t t;
 108
 109         if (!io_timeout) return;
 110
 111         if (!last_io) {
 112                 last_io = time(NULL);
 113                 return;
 114         }
 115
 116         t = time(NULL);
 117
 118         if (last_io && io_timeout && (t-last_io)>io_timeout) {
 119                 rprintf(FERROR,"read timeout after %d second - exiting\n",
 120                         (int)(t-last_io));
 121                 exit_cleanup(1);
 122         }
 123 }
 124
 125 static int readfd(int fd,char *buffer,int N)
 126 {
 127         int  ret;
 128         int total=0;
 129         struct timeval tv;
 130
 131         if (read_buffer_len < N)
 132                 read_check(buffer_f_in);
 133
 134         while (total < N) {
 135                 if (read_buffer_len > 0 && buffer_f_in == fd) {
 136                         ret = MIN(read_buffer_len,N-total);
 137                         memcpy(buffer+total,read_buffer_p,ret);
 138                         read_buffer_p += ret;
 139                         read_buffer_len -= ret;
 140                         total += ret;
 141                         continue;
 142                 }
 143
 144                 while ((ret = read(fd,buffer + total,N-total)) == -1) {
 145                         fd_set fds;
 146
 147                         if (errno != EAGAIN && errno != EWOULDBLOCK)
 148                                 return -1;
 149                         FD_ZERO(&fds);
 150                         FD_SET(fd, &fds);
 151                         tv.tv_sec = io_timeout;
 152                         tv.tv_usec = 0;
 153
 154                         if (select(fd+1, &fds, NULL, NULL,
 155                                    io_timeout?&tv:NULL) != 1) {
 156                                 check_timeout();
 157                         }
 158                 }
 159
 160                 if (ret <= 0)
 161                         return total;
 162                 total += ret;
 163         }
 164
 165         if (io_timeout)
 166                 last_io = time(NULL);
 167         return total;
 168 }
 169
 170
 171 int32 read_int(int f)
 172 {
 173   int ret;
 174   char b[4];
 175   if ((ret=readfd(f,b,4)) != 4) {
 176     if (verbose > 1)
 177       rprintf(FERROR,"(%d) Error reading %d bytes : %s\n",
 178               getpid(),4,ret==-1?strerror(errno):"EOF");
 179     exit_cleanup(1);
 180   }
 181   total_read += 4;
 182   return IVAL(b,0);
 183 }
 184
 185 int64 read_longint(int f)
 186 {
 187         extern int remote_version;
 188         int64 ret;
 189         char b[8];
 190         ret = read_int(f);
 191
 192         if ((int32)ret != (int32)0xffffffff) return ret;
 193
 194 #ifdef NO_INT64
 195         rprintf(FERROR,"Integer overflow - attempted 64 bit offset\n");
 196         exit_cleanup(1);
 197 #else
 198         if (remote_version >= 16) {
 199                 if ((ret=readfd(f,b,8)) != 8) {
 200                         if (verbose > 1)
 201                                 rprintf(FERROR,"(%d) Error reading %d bytes : %s\n",
 202                                         getpid(),8,ret==-1?strerror(errno):"EOF");
 203                         exit_cleanup(1);
 204                 }
 205                 total_read += 8;
 206                 ret = IVAL(b,0) | (((int64)IVAL(b,4))<<32);
 207         }
 208 #endif
 209
 210         return ret;
 211 }
 212
 213 void read_buf(int f,char *buf,int len)
 214 {
 215   int ret;
 216   if ((ret=readfd(f,buf,len)) != len) {
 217     if (verbose > 1)
 218       rprintf(FERROR,"(%d) Error reading %d bytes : %s\n",
 219               getpid(),len,ret==-1?strerror(errno):"EOF");
 220     exit_cleanup(1);
 221   }
 222   total_read += len;
 223 }
 224
 225 void read_sbuf(int f,char *buf,int len)
 226 {
 227         read_buf(f,buf,len);
 228         buf[len] = 0;
 229 }
 230
 231 unsigned char read_byte(int f)
 232 {
 233   unsigned char c;
 234   read_buf(f,(char *)&c,1);
 235   return c;
 236 }
 237
 238
 239 static char last_byte;
 240 static int last_sparse;
 241
 242 int sparse_end(int f)
 243 {
 244         if (last_sparse) {
 245                 do_lseek(f,-1,SEEK_CUR);
 246                 return (write(f,&last_byte,1) == 1 ? 0 : -1);
 247         }
 248         last_sparse = 0;
 249         return 0;
 250 }
 251
 252
 253 static int write_sparse(int f,char *buf,int len)
 254 {
 255         int l1=0,l2=0;
 256         int ret;
 257
 258         for (l1=0;l1<len && buf[l1]==0;l1++) ;
 259         for (l2=0;l2<(len-l1) && buf[len-(l2+1)]==0;l2++) ;
 260
 261         last_byte = buf[len-1];
 262
 263         if (l1 == len || l2 > 0)
 264                 last_sparse=1;
 265
 266         if (l1 > 0)
 267                 do_lseek(f,l1,SEEK_CUR);
 268
 269         if (l1 == len)
 270                 return len;
 271
 272         if ((ret=write(f,buf+l1,len-(l1+l2))) != len-(l1+l2)) {
 273                 if (ret == -1 || ret == 0) return ret;
 274                 return (l1+ret);
 275         }
 276
 277         if (l2 > 0)
 278                 do_lseek(f,l2,SEEK_CUR);
 279
 280         return len;
 281 }
 282
 283
 284
 285 int write_file(int f,char *buf,int len)
 286 {
 287         int ret = 0;
 288
 289         if (!sparse_files)
 290                 return write(f,buf,len);
 291
 292         while (len>0) {
 293                 int len1 = MIN(len, SPARSE_WRITE_SIZE);
 294                 int r1 = write_sparse(f, buf, len1);
 295                 if (r1 <= 0) {
 296                         if (ret > 0) return ret;
 297                         return r1;
 298                 }
 299                 len -= r1;
 300                 buf += r1;
 301                 ret += r1;
 302         }
 303         return ret;
 304 }
 305
 306
 307 static int writefd_unbuffered(int fd,char *buf,int len)
 308 {
 309   int total = 0;
 310   fd_set w_fds, r_fds;
 311   int fd_count, count, got_select=0;
 312   struct timeval tv;
 313
 314   if (buffer_f_in == -1)
 315     return write(fd,buf,len);
 316
 317   while (total < len) {
 318     int ret = write(fd,buf+total,len-total);
 319
 320     if (ret == 0) return total;
 321
 322     if (ret == -1 && !(errno == EWOULDBLOCK || errno == EAGAIN))
 323       return -1;
 324
 325     if (ret == -1 && got_select) {
 326             /* hmmm, we got a write select on the fd and then failed to write.
 327                Why doesn't that mean that the fd is dead? It doesn't on some
 328                systems it seems (eg. IRIX) */
 329             u_sleep(1000);
 330 #if 0
 331             rprintf(FERROR,"write exception\n");
 332             exit_cleanup(1);
 333 #endif
 334     }
 335
 336     got_select = 0;
 337
 338
 339     if (ret == -1) {
 340             if (read_buffer_len < MAX_READ_BUFFER)
 341                     read_check(buffer_f_in);
 342
 343             fd_count = fd+1;
 344             FD_ZERO(&w_fds);
 345             FD_ZERO(&r_fds);
 346             FD_SET(fd,&w_fds);
 347             if (buffer_f_in != -1) {
 348                     FD_SET(buffer_f_in,&r_fds);
 349                     if (buffer_f_in > fd)
 350                             fd_count = buffer_f_in+1;
 351             }
 352
 353             tv.tv_sec = BLOCKING_TIMEOUT;
 354             tv.tv_usec = 0;
 355             count = select(fd_count,buffer_f_in == -1? NULL: &r_fds,
 356                            &w_fds,NULL,&tv);
 357
 358             if (count == -1 && errno != EINTR) {
 359                     if (verbose > 1)
 360                             rprintf(FERROR,"select error: %s\n", strerror(errno));
 361                     exit_cleanup(1);
 362             }
 363
 364             if (count == 0) {
 365                     check_timeout();
 366                     continue;
 367             }
 368
 369             if (FD_ISSET(fd, &w_fds)) {
 370                     got_select = 1;
 371             }
 372     } else {
 373             total += ret;
 374     }
 375   }
 376
 377   if (io_timeout)
 378           last_io = time(NULL);
 379
 380   return total;
 381 }
 382
 383 static char *io_buffer;
 384 static int io_buffer_count;
 385
 386 void io_start_buffering(int fd)
 387 {
 388         io_buffer = (char *)malloc(IO_BUFFER_SIZE);
 389         if (!io_buffer) out_of_memory("writefd");
 390         io_buffer_count = 0;
 391 }
 392
 393 void io_end_buffering(int fd)
 394 {
 395         if (io_buffer_count) {
 396                 if (writefd_unbuffered(fd, io_buffer,
 397                                        io_buffer_count) !=
 398                     io_buffer_count) {
 399                         rprintf(FERROR,"write failed\n");
 400                         exit_cleanup(1);
 401                 }
 402                 io_buffer_count = 0;
 403         }
 404         free(io_buffer);
 405         io_buffer = NULL;
 406 }
 407
 408 static int writefd(int fd,char *buf,int len1)
 409 {
 410         int len = len1;
 411
 412         if (!io_buffer) return writefd_unbuffered(fd, buf, len);
 413
 414         while (len) {
 415                 int n = MIN(len, IO_BUFFER_SIZE-io_buffer_count);
 416                 if (n > 0) {
 417                         memcpy(io_buffer+io_buffer_count, buf, n);
 418                         buf += n;
 419                         len -= n;
 420                         io_buffer_count += n;
 421                 }
 422
 423                 if (io_buffer_count == IO_BUFFER_SIZE) {
 424                         if (writefd_unbuffered(fd, io_buffer,
 425                                                io_buffer_count) !=
 426                             io_buffer_count) {
 427                                 return -1;
 428                         }
 429                         io_buffer_count = 0;
 430                 }
 431         }
 432
 433         return len1;
 434 }
 435
 436
 437 void write_int(int f,int32 x)
 438 {
 439   int ret;
 440   char b[4];
 441   SIVAL(b,0,x);
 442   if ((ret=writefd(f,b,4)) != 4) {
 443     rprintf(FERROR,"write_int failed : %s\n",
 444             ret==-1?strerror(errno):"EOF");
 445     exit_cleanup(1);
 446   }
 447   total_written += 4;
 448 }
 449
 450 void write_longint(int f, int64 x)
 451 {
 452         extern int remote_version;
 453         char b[8];
 454         int ret;
 455
 456         if (remote_version < 16 || x <= 0x7FFFFFFF) {
 457                 write_int(f, (int)x);
 458                 return;
 459         }
 460
 461         write_int(f, -1);
 462         SIVAL(b,0,(x&0xFFFFFFFF));
 463         SIVAL(b,4,((x>>32)&0xFFFFFFFF));
 464
 465         if ((ret=writefd(f,b,8)) != 8) {
 466                 rprintf(FERROR,"write_longint failed : %s\n",
 467                         ret==-1?strerror(errno):"EOF");
 468                 exit_cleanup(1);
 469         }
 470         total_written += 8;
 471 }
 472
 473 void write_buf(int f,char *buf,int len)
 474 {
 475   int ret;
 476   if ((ret=writefd(f,buf,len)) != len) {
 477     rprintf(FERROR,"write_buf failed : %s\n",
 478             ret==-1?strerror(errno):"EOF");
 479     exit_cleanup(1);
 480   }
 481   total_written += len;
 482 }
 483
 484 /* write a string to the connection */
 485 void write_sbuf(int f,char *buf)
 486 {
 487         write_buf(f, buf, strlen(buf));
 488 }
 489
 490
 491 void write_byte(int f,unsigned char c)
 492 {
 493         write_buf(f,(char *)&c,1);
 494 }
 495
 496 void write_flush(int f)
 497 {
 498 }
 499
 500
 501 int read_line(int f, char *buf, int maxlen)
 502 {
 503         while (maxlen) {
 504                 read_buf(f, buf, 1);
 505                 if (buf[0] == '\n') {
 506                         buf[0] = 0;
 507                         break;
 508                 }
 509                 if (buf[0] != '\r') {
 510                         buf++;
 511                         maxlen--;
 512                 }
 513         }
 514         if (maxlen == 0) {
 515                 *buf = 0;
 516                 return 0;
 517         }
 518         return 1;
 519 }
 520
 521
 522 void io_printf(int fd, const char *format, ...)
 523 {
 524         va_list ap;
 525         char buf[1024];
 526         int len;
 527
 528         va_start(ap, format);
 529         len = vslprintf(buf, sizeof(buf)-1, format, ap);
 530         va_end(ap);
 531
 532         if (len < 0) exit_cleanup(1);
 533
 534         write_sbuf(fd, buf);
 535 }