sftp-server.c

   1 /* $OpenBSD: sftp-server.c,v 1.63 2006/07/17 01:31:09 stevesk Exp $ */
   2 /*
   3  * Copyright (c) 2000-2004 Markus Friedl.  All rights reserved.
   4  *
   5  * Permission to use, copy, modify, and distribute this software for any
   6  * purpose with or without fee is hereby granted, provided that the above
   7  * copyright notice and this permission notice appear in all copies.
   8  *
   9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
  10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  16  */
  17 #include "includes.h"
  18
  19 #include <sys/types.h>
  20 #include <sys/stat.h>
  21
  22 #include <dirent.h>
  23 #include <errno.h>
  24 #include <fcntl.h>
  25 #include <pwd.h>
  26 #include <unistd.h>
  27
  28 #include "buffer.h"
  29 #include "bufaux.h"
  30 #include "log.h"
  31 #include "xmalloc.h"
  32 #include "misc.h"
  33 #include "uidswap.h"
  34
  35 #include "sftp.h"
  36 #include "sftp-common.h"
  37
  38 /* helper */
  39 #define get_int64()                     buffer_get_int64(&iqueue);
  40 #define get_int()                       buffer_get_int(&iqueue);
  41 #define get_string(lenp)                buffer_get_string(&iqueue, lenp);
  42
  43 /* Our verbosity */
  44 LogLevel log_level = SYSLOG_LEVEL_ERROR;
  45
  46 /* Our client */
  47 struct passwd *pw = NULL;
  48 char *client_addr = NULL;
  49
  50 /* input and output queue */
  51 Buffer iqueue;
  52 Buffer oqueue;
  53
  54 /* Version of client */
  55 int version;
  56
  57 /* portable attributes, etc. */
  58
  59 typedef struct Stat Stat;
  60
  61 struct Stat {
  62         char *name;
  63         char *long_name;
  64         Attrib attrib;
  65 };
  66
  67 static int
  68 errno_to_portable(int unixerrno)
  69 {
  70         int ret = 0;
  71
  72         switch (unixerrno) {
  73         case 0:
  74                 ret = SSH2_FX_OK;
  75                 break;
  76         case ENOENT:
  77         case ENOTDIR:
  78         case EBADF:
  79         case ELOOP:
  80                 ret = SSH2_FX_NO_SUCH_FILE;
  81                 break;
  82         case EPERM:
  83         case EACCES:
  84         case EFAULT:
  85                 ret = SSH2_FX_PERMISSION_DENIED;
  86                 break;
  87         case ENAMETOOLONG:
  88         case EINVAL:
  89                 ret = SSH2_FX_BAD_MESSAGE;
  90                 break;
  91         default:
  92                 ret = SSH2_FX_FAILURE;
  93                 break;
  94         }
  95         return ret;
  96 }
  97
  98 static int
  99 flags_from_portable(int pflags)
 100 {
 101         int flags = 0;
 102
 103         if ((pflags & SSH2_FXF_READ) &&
 104             (pflags & SSH2_FXF_WRITE)) {
 105                 flags = O_RDWR;
 106         } else if (pflags & SSH2_FXF_READ) {
 107                 flags = O_RDONLY;
 108         } else if (pflags & SSH2_FXF_WRITE) {
 109                 flags = O_WRONLY;
 110         }
 111         if (pflags & SSH2_FXF_CREAT)
 112                 flags |= O_CREAT;
 113         if (pflags & SSH2_FXF_TRUNC)
 114                 flags |= O_TRUNC;
 115         if (pflags & SSH2_FXF_EXCL)
 116                 flags |= O_EXCL;
 117         return flags;
 118 }
 119
 120 static const char *
 121 string_from_portable(int pflags)
 122 {
 123         static char ret[128];
 124
 125         *ret = '\0';
 126
 127 #define PAPPEND(str)    {                               \
 128                 if (*ret != '\0')                       \
 129                         strlcat(ret, ",", sizeof(ret)); \
 130                 strlcat(ret, str, sizeof(ret));         \
 131         }
 132
 133         if (pflags & SSH2_FXF_READ)
 134                 PAPPEND("READ")
 135         if (pflags & SSH2_FXF_WRITE)
 136                 PAPPEND("WRITE")
 137         if (pflags & SSH2_FXF_CREAT)
 138                 PAPPEND("CREATE")
 139         if (pflags & SSH2_FXF_TRUNC)
 140                 PAPPEND("TRUNCATE")
 141         if (pflags & SSH2_FXF_EXCL)
 142                 PAPPEND("EXCL")
 143
 144         return ret;
 145 }
 146
 147 static Attrib *
 148 get_attrib(void)
 149 {
 150         return decode_attrib(&iqueue);
 151 }
 152
 153 /* handle handles */
 154
 155 typedef struct Handle Handle;
 156 struct Handle {
 157         int use;
 158         DIR *dirp;
 159         int fd;
 160         char *name;
 161         u_int64_t bytes_read, bytes_write;
 162 };
 163
 164 enum {
 165         HANDLE_UNUSED,
 166         HANDLE_DIR,
 167         HANDLE_FILE
 168 };
 169
 170 Handle  handles[100];
 171
 172 static void
 173 handle_init(void)
 174 {
 175         u_int i;
 176
 177         for (i = 0; i < sizeof(handles)/sizeof(Handle); i++)
 178                 handles[i].use = HANDLE_UNUSED;
 179 }
 180
 181 static int
 182 handle_new(int use, const char *name, int fd, DIR *dirp)
 183 {
 184         u_int i;
 185
 186         for (i = 0; i < sizeof(handles)/sizeof(Handle); i++) {
 187                 if (handles[i].use == HANDLE_UNUSED) {
 188                         handles[i].use = use;
 189                         handles[i].dirp = dirp;
 190                         handles[i].fd = fd;
 191                         handles[i].name = xstrdup(name);
 192                         handles[i].bytes_read = handles[i].bytes_write = 0;
 193                         return i;
 194                 }
 195         }
 196         return -1;
 197 }
 198
 199 static int
 200 handle_is_ok(int i, int type)
 201 {
 202         return i >= 0 && (u_int)i < sizeof(handles)/sizeof(Handle) &&
 203             handles[i].use == type;
 204 }
 205
 206 static int
 207 handle_to_string(int handle, char **stringp, int *hlenp)
 208 {
 209         if (stringp == NULL || hlenp == NULL)
 210                 return -1;
 211         *stringp = xmalloc(sizeof(int32_t));
 212         put_u32(*stringp, handle);
 213         *hlenp = sizeof(int32_t);
 214         return 0;
 215 }
 216
 217 static int
 218 handle_from_string(const char *handle, u_int hlen)
 219 {
 220         int val;
 221
 222         if (hlen != sizeof(int32_t))
 223                 return -1;
 224         val = get_u32(handle);
 225         if (handle_is_ok(val, HANDLE_FILE) ||
 226             handle_is_ok(val, HANDLE_DIR))
 227                 return val;
 228         return -1;
 229 }
 230
 231 static char *
 232 handle_to_name(int handle)
 233 {
 234         if (handle_is_ok(handle, HANDLE_DIR)||
 235             handle_is_ok(handle, HANDLE_FILE))
 236                 return handles[handle].name;
 237         return NULL;
 238 }
 239
 240 static DIR *
 241 handle_to_dir(int handle)
 242 {
 243         if (handle_is_ok(handle, HANDLE_DIR))
 244                 return handles[handle].dirp;
 245         return NULL;
 246 }
 247
 248 static int
 249 handle_to_fd(int handle)
 250 {
 251         if (handle_is_ok(handle, HANDLE_FILE))
 252                 return handles[handle].fd;
 253         return -1;
 254 }
 255
 256 static void
 257 handle_update_read(int handle, ssize_t bytes)
 258 {
 259         if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
 260                 handles[handle].bytes_read += bytes;
 261 }
 262
 263 static void
 264 handle_update_write(int handle, ssize_t bytes)
 265 {
 266         if (handle_is_ok(handle, HANDLE_FILE) && bytes > 0)
 267                 handles[handle].bytes_write += bytes;
 268 }
 269
 270 static u_int64_t
 271 handle_bytes_read(int handle)
 272 {
 273         if (handle_is_ok(handle, HANDLE_FILE))
 274                 return (handles[handle].bytes_read);
 275         return 0;
 276 }
 277
 278 static u_int64_t
 279 handle_bytes_write(int handle)
 280 {
 281         if (handle_is_ok(handle, HANDLE_FILE))
 282                 return (handles[handle].bytes_write);
 283         return 0;
 284 }
 285
 286 static int
 287 handle_close(int handle)
 288 {
 289         int ret = -1;
 290
 291         if (handle_is_ok(handle, HANDLE_FILE)) {
 292                 ret = close(handles[handle].fd);
 293                 handles[handle].use = HANDLE_UNUSED;
 294                 xfree(handles[handle].name);
 295         } else if (handle_is_ok(handle, HANDLE_DIR)) {
 296                 ret = closedir(handles[handle].dirp);
 297                 handles[handle].use = HANDLE_UNUSED;
 298                 xfree(handles[handle].name);
 299         } else {
 300                 errno = ENOENT;
 301         }
 302         return ret;
 303 }
 304
 305 static void
 306 handle_log_close(int handle, char *emsg)
 307 {
 308         if (handle_is_ok(handle, HANDLE_FILE)) {
 309                 logit("%s%sclose \"%s\" bytes read %llu written %llu",
 310                     emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
 311                     handle_to_name(handle),
 312                     handle_bytes_read(handle), handle_bytes_write(handle));
 313         } else {
 314                 logit("%s%sclosedir \"%s\"",
 315                     emsg == NULL ? "" : emsg, emsg == NULL ? "" : " ",
 316                     handle_to_name(handle));
 317         }
 318 }
 319
 320 static void
 321 handle_log_exit(void)
 322 {
 323         u_int i;
 324
 325         for (i = 0; i < sizeof(handles)/sizeof(Handle); i++)
 326                 if (handles[i].use != HANDLE_UNUSED)
 327                         handle_log_close(i, "forced");
 328 }
 329
 330 static int
 331 get_handle(void)
 332 {
 333         char *handle;
 334         int val = -1;
 335         u_int hlen;
 336
 337         handle = get_string(&hlen);
 338         if (hlen < 256)
 339                 val = handle_from_string(handle, hlen);
 340         xfree(handle);
 341         return val;
 342 }
 343
 344 /* send replies */
 345
 346 static void
 347 send_msg(Buffer *m)
 348 {
 349         int mlen = buffer_len(m);
 350
 351         buffer_put_int(&oqueue, mlen);
 352         buffer_append(&oqueue, buffer_ptr(m), mlen);
 353         buffer_consume(m, mlen);
 354 }
 355
 356 static const char *
 357 status_to_message(u_int32_t status)
 358 {
 359         const char *status_messages[] = {
 360                 "Success",                      /* SSH_FX_OK */
 361                 "End of file",                  /* SSH_FX_EOF */
 362                 "No such file",                 /* SSH_FX_NO_SUCH_FILE */
 363                 "Permission denied",            /* SSH_FX_PERMISSION_DENIED */
 364                 "Failure",                      /* SSH_FX_FAILURE */
 365                 "Bad message",                  /* SSH_FX_BAD_MESSAGE */
 366                 "No connection",                /* SSH_FX_NO_CONNECTION */
 367                 "Connection lost",              /* SSH_FX_CONNECTION_LOST */
 368                 "Operation unsupported",        /* SSH_FX_OP_UNSUPPORTED */
 369                 "Unknown error"                 /* Others */
 370         };
 371         return (status_messages[MIN(status,SSH2_FX_MAX)]);
 372 }
 373
 374 static void
 375 send_status(u_int32_t id, u_int32_t status)
 376 {
 377         Buffer msg;
 378
 379         debug3("request %u: sent status %u", id, status);
 380         if (log_level > SYSLOG_LEVEL_VERBOSE ||
 381             (status != SSH2_FX_OK && status != SSH2_FX_EOF))
 382                 logit("sent status %s", status_to_message(status));
 383         buffer_init(&msg);
 384         buffer_put_char(&msg, SSH2_FXP_STATUS);
 385         buffer_put_int(&msg, id);
 386         buffer_put_int(&msg, status);
 387         if (version >= 3) {
 388                 buffer_put_cstring(&msg, status_to_message(status));
 389                 buffer_put_cstring(&msg, "");
 390         }
 391         send_msg(&msg);
 392         buffer_free(&msg);
 393 }
 394 static void
 395 send_data_or_handle(char type, u_int32_t id, const char *data, int dlen)
 396 {
 397         Buffer msg;
 398
 399         buffer_init(&msg);
 400         buffer_put_char(&msg, type);
 401         buffer_put_int(&msg, id);
 402         buffer_put_string(&msg, data, dlen);
 403         send_msg(&msg);
 404         buffer_free(&msg);
 405 }
 406
 407 static void
 408 send_data(u_int32_t id, const char *data, int dlen)
 409 {
 410         debug("request %u: sent data len %d", id, dlen);
 411         send_data_or_handle(SSH2_FXP_DATA, id, data, dlen);
 412 }
 413
 414 static void
 415 send_handle(u_int32_t id, int handle)
 416 {
 417         char *string;
 418         int hlen;
 419
 420         handle_to_string(handle, &string, &hlen);
 421         debug("request %u: sent handle handle %d", id, handle);
 422         send_data_or_handle(SSH2_FXP_HANDLE, id, string, hlen);
 423         xfree(string);
 424 }
 425
 426 static void
 427 send_names(u_int32_t id, int count, const Stat *stats)
 428 {
 429         Buffer msg;
 430         int i;
 431
 432         buffer_init(&msg);
 433         buffer_put_char(&msg, SSH2_FXP_NAME);
 434         buffer_put_int(&msg, id);
 435         buffer_put_int(&msg, count);
 436         debug("request %u: sent names count %d", id, count);
 437         for (i = 0; i < count; i++) {
 438                 buffer_put_cstring(&msg, stats[i].name);
 439                 buffer_put_cstring(&msg, stats[i].long_name);
 440                 encode_attrib(&msg, &stats[i].attrib);
 441         }
 442         send_msg(&msg);
 443         buffer_free(&msg);
 444 }
 445
 446 static void
 447 send_attrib(u_int32_t id, const Attrib *a)
 448 {
 449         Buffer msg;
 450
 451         debug("request %u: sent attrib have 0x%x", id, a->flags);
 452         buffer_init(&msg);
 453         buffer_put_char(&msg, SSH2_FXP_ATTRS);
 454         buffer_put_int(&msg, id);
 455         encode_attrib(&msg, a);
 456         send_msg(&msg);
 457         buffer_free(&msg);
 458 }
 459
 460 /* parse incoming */
 461
 462 static void
 463 process_init(void)
 464 {
 465         Buffer msg;
 466
 467         version = get_int();
 468         verbose("received client version %d", version);
 469         buffer_init(&msg);
 470         buffer_put_char(&msg, SSH2_FXP_VERSION);
 471         buffer_put_int(&msg, SSH2_FILEXFER_VERSION);
 472         send_msg(&msg);
 473         buffer_free(&msg);
 474 }
 475
 476 static void
 477 process_open(void)
 478 {
 479         u_int32_t id, pflags;
 480         Attrib *a;
 481         char *name;
 482         int handle, fd, flags, mode, status = SSH2_FX_FAILURE;
 483
 484         id = get_int();
 485         name = get_string(NULL);
 486         pflags = get_int();             /* portable flags */
 487         debug3("request %u: open flags %d", id, pflags);
 488         a = get_attrib();
 489         flags = flags_from_portable(pflags);
 490         mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ? a->perm : 0666;
 491         logit("open \"%s\" flags %s mode 0%o",
 492             name, string_from_portable(pflags), mode);
 493         fd = open(name, flags, mode);
 494         if (fd < 0) {
 495                 status = errno_to_portable(errno);
 496         } else {
 497                 handle = handle_new(HANDLE_FILE, name, fd, NULL);
 498                 if (handle < 0) {
 499                         close(fd);
 500                 } else {
 501                         send_handle(id, handle);
 502                         status = SSH2_FX_OK;
 503                 }
 504         }
 505         if (status != SSH2_FX_OK)
 506                 send_status(id, status);
 507         xfree(name);
 508 }
 509
 510 static void
 511 process_close(void)
 512 {
 513         u_int32_t id;
 514         int handle, ret, status = SSH2_FX_FAILURE;
 515
 516         id = get_int();
 517         handle = get_handle();
 518         debug3("request %u: close handle %u", id, handle);
 519         handle_log_close(handle, NULL);
 520         ret = handle_close(handle);
 521         status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
 522         send_status(id, status);
 523 }
 524
 525 static void
 526 process_read(void)
 527 {
 528         char buf[64*1024];
 529         u_int32_t id, len;
 530         int handle, fd, ret, status = SSH2_FX_FAILURE;
 531         u_int64_t off;
 532
 533         id = get_int();
 534         handle = get_handle();
 535         off = get_int64();
 536         len = get_int();
 537
 538         debug("request %u: read \"%s\" (handle %d) off %llu len %d",
 539             id, handle_to_name(handle), handle, (unsigned long long)off, len);
 540         if (len > sizeof buf) {
 541                 len = sizeof buf;
 542                 debug2("read change len %d", len);
 543         }
 544         fd = handle_to_fd(handle);
 545         if (fd >= 0) {
 546                 if (lseek(fd, off, SEEK_SET) < 0) {
 547                         error("process_read: seek failed");
 548                         status = errno_to_portable(errno);
 549                 } else {
 550                         ret = read(fd, buf, len);
 551                         if (ret < 0) {
 552                                 status = errno_to_portable(errno);
 553                         } else if (ret == 0) {
 554                                 status = SSH2_FX_EOF;
 555                         } else {
 556                                 send_data(id, buf, ret);
 557                                 status = SSH2_FX_OK;
 558                                 handle_update_read(handle, ret);
 559                         }
 560                 }
 561         }
 562         if (status != SSH2_FX_OK)
 563                 send_status(id, status);
 564 }
 565
 566 static void
 567 process_write(void)
 568 {
 569         u_int32_t id;
 570         u_int64_t off;
 571         u_int len;
 572         int handle, fd, ret, status = SSH2_FX_FAILURE;
 573         char *data;
 574
 575         id = get_int();
 576         handle = get_handle();
 577         off = get_int64();
 578         data = get_string(&len);
 579
 580         debug("request %u: write \"%s\" (handle %d) off %llu len %d",
 581             id, handle_to_name(handle), handle, (unsigned long long)off, len);
 582         fd = handle_to_fd(handle);
 583         if (fd >= 0) {
 584                 if (lseek(fd, off, SEEK_SET) < 0) {
 585                         status = errno_to_portable(errno);
 586                         error("process_write: seek failed");
 587                 } else {
 588 /* XXX ATOMICIO ? */
 589                         ret = write(fd, data, len);
 590                         if (ret < 0) {
 591                                 error("process_write: write failed");
 592                                 status = errno_to_portable(errno);
 593                         } else if ((size_t)ret == len) {
 594                                 status = SSH2_FX_OK;
 595                                 handle_update_write(handle, ret);
 596                         } else {
 597                                 debug2("nothing at all written");
 598                         }
 599                 }
 600         }
 601         send_status(id, status);
 602         xfree(data);
 603 }
 604
 605 static void
 606 process_do_stat(int do_lstat)
 607 {
 608         Attrib a;
 609         struct stat st;
 610         u_int32_t id;
 611         char *name;
 612         int ret, status = SSH2_FX_FAILURE;
 613
 614         id = get_int();
 615         name = get_string(NULL);
 616         debug3("request %u: %sstat", id, do_lstat ? "l" : "");
 617         verbose("%sstat name \"%s\"", do_lstat ? "l" : "", name);
 618         ret = do_lstat ? lstat(name, &st) : stat(name, &st);
 619         if (ret < 0) {
 620                 status = errno_to_portable(errno);
 621         } else {
 622                 stat_to_attrib(&st, &a);
 623                 send_attrib(id, &a);
 624                 status = SSH2_FX_OK;
 625         }
 626         if (status != SSH2_FX_OK)
 627                 send_status(id, status);
 628         xfree(name);
 629 }
 630
 631 static void
 632 process_stat(void)
 633 {
 634         process_do_stat(0);
 635 }
 636
 637 static void
 638 process_lstat(void)
 639 {
 640         process_do_stat(1);
 641 }
 642
 643 static void
 644 process_fstat(void)
 645 {
 646         Attrib a;
 647         struct stat st;
 648         u_int32_t id;
 649         int fd, ret, handle, status = SSH2_FX_FAILURE;
 650
 651         id = get_int();
 652         handle = get_handle();
 653         debug("request %u: fstat \"%s\" (handle %u)",
 654             id, handle_to_name(handle), handle);
 655         fd = handle_to_fd(handle);
 656         if (fd  >= 0) {
 657                 ret = fstat(fd, &st);
 658                 if (ret < 0) {
 659                         status = errno_to_portable(errno);
 660                 } else {
 661                         stat_to_attrib(&st, &a);
 662                         send_attrib(id, &a);
 663                         status = SSH2_FX_OK;
 664                 }
 665         }
 666         if (status != SSH2_FX_OK)
 667                 send_status(id, status);
 668 }
 669
 670 static struct timeval *
 671 attrib_to_tv(const Attrib *a)
 672 {
 673         static struct timeval tv[2];
 674
 675         tv[0].tv_sec = a->atime;
 676         tv[0].tv_usec = 0;
 677         tv[1].tv_sec = a->mtime;
 678         tv[1].tv_usec = 0;
 679         return tv;
 680 }
 681
 682 static void
 683 process_setstat(void)
 684 {
 685         Attrib *a;
 686         u_int32_t id;
 687         char *name;
 688         int status = SSH2_FX_OK, ret;
 689
 690         id = get_int();
 691         name = get_string(NULL);
 692         a = get_attrib();
 693         debug("request %u: setstat name \"%s\"", id, name);
 694         if (a->flags & SSH2_FILEXFER_ATTR_SIZE) {
 695                 logit("set \"%s\" size %llu", name, a->size);
 696                 ret = truncate(name, a->size);
 697                 if (ret == -1)
 698                         status = errno_to_portable(errno);
 699         }
 700         if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
 701                 logit("set \"%s\" mode %04o", name, a->perm);
 702                 ret = chmod(name, a->perm & 0777);
 703                 if (ret == -1)
 704                         status = errno_to_portable(errno);
 705         }
 706         if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
 707                 char buf[64];
 708                 time_t t = a->mtime;
 709
 710                 strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
 711                     localtime(&t));
 712                 logit("set \"%s\" modtime %s", name, buf);
 713                 ret = utimes(name, attrib_to_tv(a));
 714                 if (ret == -1)
 715                         status = errno_to_portable(errno);
 716         }
 717         if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) {
 718                 logit("set \"%s\" owner %lu group %lu", name,
 719                     (u_long)a->uid, (u_long)a->gid);
 720                 ret = chown(name, a->uid, a->gid);
 721                 if (ret == -1)
 722                         status = errno_to_portable(errno);
 723         }
 724         send_status(id, status);
 725         xfree(name);
 726 }
 727
 728 static void
 729 process_fsetstat(void)
 730 {
 731         Attrib *a;
 732         u_int32_t id;
 733         int handle, fd, ret;
 734         int status = SSH2_FX_OK;
 735
 736         id = get_int();
 737         handle = get_handle();
 738         a = get_attrib();
 739         debug("request %u: fsetstat handle %d", id, handle);
 740         fd = handle_to_fd(handle);
 741         if (fd < 0) {
 742                 status = SSH2_FX_FAILURE;
 743         } else {
 744                 char *name = handle_to_name(handle);
 745
 746                 if (a->flags & SSH2_FILEXFER_ATTR_SIZE) {
 747                         logit("set \"%s\" size %llu", name, a->size);
 748                         ret = ftruncate(fd, a->size);
 749                         if (ret == -1)
 750                                 status = errno_to_portable(errno);
 751                 }
 752                 if (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) {
 753                         logit("set \"%s\" mode %04o", name, a->perm);
 754 #ifdef HAVE_FCHMOD
 755                         ret = fchmod(fd, a->perm & 0777);
 756 #else
 757                         ret = chmod(name, a->perm & 0777);
 758 #endif
 759                         if (ret == -1)
 760                                 status = errno_to_portable(errno);
 761                 }
 762                 if (a->flags & SSH2_FILEXFER_ATTR_ACMODTIME) {
 763                         char buf[64];
 764                         time_t t = a->mtime;
 765
 766                         strftime(buf, sizeof(buf), "%Y%m%d-%H:%M:%S",
 767                             localtime(&t));
 768                         logit("set \"%s\" modtime %s", name, buf);
 769 #ifdef HAVE_FUTIMES
 770                         ret = futimes(fd, attrib_to_tv(a));
 771 #else
 772                         ret = utimes(name, attrib_to_tv(a));
 773 #endif
 774                         if (ret == -1)
 775                                 status = errno_to_portable(errno);
 776                 }
 777                 if (a->flags & SSH2_FILEXFER_ATTR_UIDGID) {
 778                         logit("set \"%s\" owner %lu group %lu", name,
 779                             (u_long)a->uid, (u_long)a->gid);
 780 #ifdef HAVE_FCHOWN
 781                         ret = fchown(fd, a->uid, a->gid);
 782 #else
 783                         ret = chown(name, a->uid, a->gid);
 784 #endif
 785                         if (ret == -1)
 786                                 status = errno_to_portable(errno);
 787                 }
 788         }
 789         send_status(id, status);
 790 }
 791
 792 static void
 793 process_opendir(void)
 794 {
 795         DIR *dirp = NULL;
 796         char *path;
 797         int handle, status = SSH2_FX_FAILURE;
 798         u_int32_t id;
 799
 800         id = get_int();
 801         path = get_string(NULL);
 802         debug3("request %u: opendir", id);
 803         logit("opendir \"%s\"", path);
 804         dirp = opendir(path);
 805         if (dirp == NULL) {
 806                 status = errno_to_portable(errno);
 807         } else {
 808                 handle = handle_new(HANDLE_DIR, path, 0, dirp);
 809                 if (handle < 0) {
 810                         closedir(dirp);
 811                 } else {
 812                         send_handle(id, handle);
 813                         status = SSH2_FX_OK;
 814                 }
 815
 816         }
 817         if (status != SSH2_FX_OK)
 818                 send_status(id, status);
 819         xfree(path);
 820 }
 821
 822 static void
 823 process_readdir(void)
 824 {
 825         DIR *dirp;
 826         struct dirent *dp;
 827         char *path;
 828         int handle;
 829         u_int32_t id;
 830
 831         id = get_int();
 832         handle = get_handle();
 833         debug("request %u: readdir \"%s\" (handle %d)", id,
 834             handle_to_name(handle), handle);
 835         dirp = handle_to_dir(handle);
 836         path = handle_to_name(handle);
 837         if (dirp == NULL || path == NULL) {
 838                 send_status(id, SSH2_FX_FAILURE);
 839         } else {
 840                 struct stat st;
 841                 char pathname[MAXPATHLEN];
 842                 Stat *stats;
 843                 int nstats = 10, count = 0, i;
 844
 845                 stats = xcalloc(nstats, sizeof(Stat));
 846                 while ((dp = readdir(dirp)) != NULL) {
 847                         if (count >= nstats) {
 848                                 nstats *= 2;
 849                                 stats = xrealloc(stats, nstats, sizeof(Stat));
 850                         }
 851 /* XXX OVERFLOW ? */
 852                         snprintf(pathname, sizeof pathname, "%s%s%s", path,
 853                             strcmp(path, "/") ? "/" : "", dp->d_name);
 854                         if (lstat(pathname, &st) < 0)
 855                                 continue;
 856                         stat_to_attrib(&st, &(stats[count].attrib));
 857                         stats[count].name = xstrdup(dp->d_name);
 858                         stats[count].long_name = ls_file(dp->d_name, &st, 0);
 859                         count++;
 860                         /* send up to 100 entries in one message */
 861                         /* XXX check packet size instead */
 862                         if (count == 100)
 863                                 break;
 864                 }
 865                 if (count > 0) {
 866                         send_names(id, count, stats);
 867                         for (i = 0; i < count; i++) {
 868                                 xfree(stats[i].name);
 869                                 xfree(stats[i].long_name);
 870                         }
 871                 } else {
 872                         send_status(id, SSH2_FX_EOF);
 873                 }
 874                 xfree(stats);
 875         }
 876 }
 877
 878 static void
 879 process_remove(void)
 880 {
 881         char *name;
 882         u_int32_t id;
 883         int status = SSH2_FX_FAILURE;
 884         int ret;
 885
 886         id = get_int();
 887         name = get_string(NULL);
 888         debug3("request %u: remove", id);
 889         logit("remove name \"%s\"", name);
 890         ret = unlink(name);
 891         status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
 892         send_status(id, status);
 893         xfree(name);
 894 }
 895
 896 static void
 897 process_mkdir(void)
 898 {
 899         Attrib *a;
 900         u_int32_t id;
 901         char *name;
 902         int ret, mode, status = SSH2_FX_FAILURE;
 903
 904         id = get_int();
 905         name = get_string(NULL);
 906         a = get_attrib();
 907         mode = (a->flags & SSH2_FILEXFER_ATTR_PERMISSIONS) ?
 908             a->perm & 0777 : 0777;
 909         debug3("request %u: mkdir", id);
 910         logit("mkdir name \"%s\" mode 0%o", name, mode);
 911         ret = mkdir(name, mode);
 912         status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
 913         send_status(id, status);
 914         xfree(name);
 915 }
 916
 917 static void
 918 process_rmdir(void)
 919 {
 920         u_int32_t id;
 921         char *name;
 922         int ret, status;
 923
 924         id = get_int();
 925         name = get_string(NULL);
 926         debug3("request %u: rmdir", id);
 927         logit("rmdir name \"%s\"", name);
 928         ret = rmdir(name);
 929         status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
 930         send_status(id, status);
 931         xfree(name);
 932 }
 933
 934 static void
 935 process_realpath(void)
 936 {
 937         char resolvedname[MAXPATHLEN];
 938         u_int32_t id;
 939         char *path;
 940
 941         id = get_int();
 942         path = get_string(NULL);
 943         if (path[0] == '\0') {
 944                 xfree(path);
 945                 path = xstrdup(".");
 946         }
 947         debug3("request %u: realpath", id);
 948         verbose("realpath \"%s\"", path);
 949         if (realpath(path, resolvedname) == NULL) {
 950                 send_status(id, errno_to_portable(errno));
 951         } else {
 952                 Stat s;
 953                 attrib_clear(&s.attrib);
 954                 s.name = s.long_name = resolvedname;
 955                 send_names(id, 1, &s);
 956         }
 957         xfree(path);
 958 }
 959
 960 static void
 961 process_rename(void)
 962 {
 963         u_int32_t id;
 964         char *oldpath, *newpath;
 965         int status;
 966         struct stat sb;
 967
 968         id = get_int();
 969         oldpath = get_string(NULL);
 970         newpath = get_string(NULL);
 971         debug3("request %u: rename", id);
 972         logit("rename old \"%s\" new \"%s\"", oldpath, newpath);
 973         status = SSH2_FX_FAILURE;
 974         if (lstat(oldpath, &sb) == -1)
 975                 status = errno_to_portable(errno);
 976         else if (S_ISREG(sb.st_mode)) {
 977                 /* Race-free rename of regular files */
 978                 if (link(oldpath, newpath) == -1) {
 979                         if (errno == EOPNOTSUPP
 980 #ifdef LINK_OPNOTSUPP_ERRNO
 981                             || errno == LINK_OPNOTSUPP_ERRNO
 982 #endif
 983                             ) {
 984                                 struct stat st;
 985
 986                                 /*
 987                                  * fs doesn't support links, so fall back to
 988                                  * stat+rename.  This is racy.
 989                                  */
 990                                 if (stat(newpath, &st) == -1) {
 991                                         if (rename(oldpath, newpath) == -1)
 992                                                 status =
 993                                                     errno_to_portable(errno);
 994                                         else
 995                                                 status = SSH2_FX_OK;
 996                                 }
 997                         } else {
 998                                 status = errno_to_portable(errno);
 999                         }
1000                 } else if (unlink(oldpath) == -1) {
1001                         status = errno_to_portable(errno);
1002                         /* clean spare link */
1003                         unlink(newpath);
1004                 } else
1005                         status = SSH2_FX_OK;
1006         } else if (stat(newpath, &sb) == -1) {
1007                 if (rename(oldpath, newpath) == -1)
1008                         status = errno_to_portable(errno);
1009                 else
1010                         status = SSH2_FX_OK;
1011         }
1012         send_status(id, status);
1013         xfree(oldpath);
1014         xfree(newpath);
1015 }
1016
1017 static void
1018 process_readlink(void)
1019 {
1020         u_int32_t id;
1021         int len;
1022         char buf[MAXPATHLEN];
1023         char *path;
1024
1025         id = get_int();
1026         path = get_string(NULL);
1027         debug3("request %u: readlink", id);
1028         verbose("readlink \"%s\"", path);
1029         if ((len = readlink(path, buf, sizeof(buf) - 1)) == -1)
1030                 send_status(id, errno_to_portable(errno));
1031         else {
1032                 Stat s;
1033
1034                 buf[len] = '\0';
1035                 attrib_clear(&s.attrib);
1036                 s.name = s.long_name = buf;
1037                 send_names(id, 1, &s);
1038         }
1039         xfree(path);
1040 }
1041
1042 static void
1043 process_symlink(void)
1044 {
1045         u_int32_t id;
1046         char *oldpath, *newpath;
1047         int ret, status;
1048
1049         id = get_int();
1050         oldpath = get_string(NULL);
1051         newpath = get_string(NULL);
1052         debug3("request %u: symlink", id);
1053         logit("symlink old \"%s\" new \"%s\"", oldpath, newpath);
1054         /* this will fail if 'newpath' exists */
1055         ret = symlink(oldpath, newpath);
1056         status = (ret == -1) ? errno_to_portable(errno) : SSH2_FX_OK;
1057         send_status(id, status);
1058         xfree(oldpath);
1059         xfree(newpath);
1060 }
1061
1062 static void
1063 process_extended(void)
1064 {
1065         u_int32_t id;
1066         char *request;
1067
1068         id = get_int();
1069         request = get_string(NULL);
1070         send_status(id, SSH2_FX_OP_UNSUPPORTED);                /* MUST */
1071         xfree(request);
1072 }
1073
1074 /* stolen from ssh-agent */
1075
1076 static void
1077 process(void)
1078 {
1079         u_int msg_len;
1080         u_int buf_len;
1081         u_int consumed;
1082         u_int type;
1083         u_char *cp;
1084
1085         buf_len = buffer_len(&iqueue);
1086         if (buf_len < 5)
1087                 return;         /* Incomplete message. */
1088         cp = buffer_ptr(&iqueue);
1089         msg_len = get_u32(cp);
1090         if (msg_len > SFTP_MAX_MSG_LENGTH) {
1091                 error("bad message from %s local user %s",
1092                     client_addr, pw->pw_name);
1093                 cleanup_exit(11);
1094         }
1095         if (buf_len < msg_len + 4)
1096                 return;
1097         buffer_consume(&iqueue, 4);
1098         buf_len -= 4;
1099         type = buffer_get_char(&iqueue);
1100         switch (type) {
1101         case SSH2_FXP_INIT:
1102                 process_init();
1103                 break;
1104         case SSH2_FXP_OPEN:
1105                 process_open();
1106                 break;
1107         case SSH2_FXP_CLOSE:
1108                 process_close();
1109                 break;
1110         case SSH2_FXP_READ:
1111                 process_read();
1112                 break;
1113         case SSH2_FXP_WRITE:
1114                 process_write();
1115                 break;
1116         case SSH2_FXP_LSTAT:
1117                 process_lstat();
1118                 break;
1119         case SSH2_FXP_FSTAT:
1120                 process_fstat();
1121                 break;
1122         case SSH2_FXP_SETSTAT:
1123                 process_setstat();
1124                 break;
1125         case SSH2_FXP_FSETSTAT:
1126                 process_fsetstat();
1127                 break;
1128         case SSH2_FXP_OPENDIR:
1129                 process_opendir();
1130                 break;
1131         case SSH2_FXP_READDIR:
1132                 process_readdir();
1133                 break;
1134         case SSH2_FXP_REMOVE:
1135                 process_remove();
1136                 break;
1137         case SSH2_FXP_MKDIR:
1138                 process_mkdir();
1139                 break;
1140         case SSH2_FXP_RMDIR:
1141                 process_rmdir();
1142                 break;
1143         case SSH2_FXP_REALPATH:
1144                 process_realpath();
1145                 break;
1146         case SSH2_FXP_STAT:
1147                 process_stat();
1148                 break;
1149         case SSH2_FXP_RENAME:
1150                 process_rename();
1151                 break;
1152         case SSH2_FXP_READLINK:
1153                 process_readlink();
1154                 break;
1155         case SSH2_FXP_SYMLINK:
1156                 process_symlink();
1157                 break;
1158         case SSH2_FXP_EXTENDED:
1159                 process_extended();
1160                 break;
1161         default:
1162                 error("Unknown message %d", type);
1163                 break;
1164         }
1165         /* discard the remaining bytes from the current packet */
1166         if (buf_len < buffer_len(&iqueue))
1167                 fatal("iqueue grew unexpectedly");
1168         consumed = buf_len - buffer_len(&iqueue);
1169         if (msg_len < consumed)
1170                 fatal("msg_len %d < consumed %d", msg_len, consumed);
1171         if (msg_len > consumed)
1172                 buffer_consume(&iqueue, msg_len - consumed);
1173 }
1174
1175 /* Cleanup handler that logs active handles upon normal exit */
1176 void
1177 cleanup_exit(int i)
1178 {
1179         if (pw != NULL && client_addr != NULL) {
1180                 handle_log_exit();
1181                 logit("session closed for local user %s from [%s]",
1182                     pw->pw_name, client_addr);
1183         }
1184         _exit(i);
1185 }
1186
1187 static void
1188 usage(void)
1189 {
1190         extern char *__progname;
1191
1192         fprintf(stderr,
1193             "usage: %s [-he] [-l log_level] [-f log_facility]\n", __progname);
1194         exit(1);
1195 }
1196
1197 int
1198 main(int argc, char **argv)
1199 {
1200         fd_set *rset, *wset;
1201         int in, out, max, ch, skipargs = 0, log_stderr = 0;
1202         ssize_t len, olen, set_size;
1203         SyslogFacility log_facility = SYSLOG_FACILITY_AUTH;
1204         char *cp;
1205
1206         extern char *optarg;
1207         extern char *__progname;
1208
1209         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1210         sanitise_stdfd();
1211
1212         __progname = ssh_get_progname(argv[0]);
1213         log_init(__progname, log_level, log_facility, log_stderr);
1214
1215         while (!skipargs && (ch = getopt(argc, argv, "C:f:l:che")) != -1) {
1216                 switch (ch) {
1217                 case 'c':
1218                         /*
1219                          * Ignore all arguments if we are invoked as a
1220                          * shell using "sftp-server -c command"
1221                          */
1222                         skipargs = 1;
1223                         break;
1224                 case 'e':
1225                         log_stderr = 1;
1226                         break;
1227                 case 'l':
1228                         log_level = log_level_number(optarg);
1229                         if (log_level == SYSLOG_LEVEL_NOT_SET)
1230                                 error("Invalid log level \"%s\"", optarg);
1231                         break;
1232                 case 'f':
1233                         log_facility = log_facility_number(optarg);
1234                         if (log_level == SYSLOG_FACILITY_NOT_SET)
1235                                 error("Invalid log facility \"%s\"", optarg);
1236                         break;
1237                 case 'h':
1238                 default:
1239                         usage();
1240                 }
1241         }
1242
1243         log_init(__progname, log_level, log_facility, log_stderr);
1244
1245         if ((cp = getenv("SSH_CONNECTION")) != NULL) {
1246                 client_addr = xstrdup(cp);
1247                 if ((cp = strchr(client_addr, ' ')) == NULL)
1248                         fatal("Malformed SSH_CONNECTION variable: \"%s\"",
1249                             getenv("SSH_CONNECTION"));
1250                 *cp = '\0';
1251         } else
1252                 client_addr = xstrdup("UNKNOWN");
1253
1254         if ((pw = getpwuid(getuid())) == NULL)
1255                 fatal("No user found for uid %lu", (u_long)getuid());
1256         pw = pwcopy(pw);
1257
1258         logit("session opened for local user %s from [%s]",
1259             pw->pw_name, client_addr);
1260
1261         handle_init();
1262
1263         in = dup(STDIN_FILENO);
1264         out = dup(STDOUT_FILENO);
1265
1266 #ifdef HAVE_CYGWIN
1267         setmode(in, O_BINARY);
1268         setmode(out, O_BINARY);
1269 #endif
1270
1271         max = 0;
1272         if (in > max)
1273                 max = in;
1274         if (out > max)
1275                 max = out;
1276
1277         buffer_init(&iqueue);
1278         buffer_init(&oqueue);
1279
1280         set_size = howmany(max + 1, NFDBITS) * sizeof(fd_mask);
1281         rset = (fd_set *)xmalloc(set_size);
1282         wset = (fd_set *)xmalloc(set_size);
1283
1284         for (;;) {
1285                 memset(rset, 0, set_size);
1286                 memset(wset, 0, set_size);
1287
1288                 FD_SET(in, rset);
1289                 olen = buffer_len(&oqueue);
1290                 if (olen > 0)
1291                         FD_SET(out, wset);
1292
1293                 if (select(max+1, rset, wset, NULL, NULL) < 0) {
1294                         if (errno == EINTR)
1295                                 continue;
1296                         error("select: %s", strerror(errno));
1297                         cleanup_exit(2);
1298                 }
1299
1300                 /* copy stdin to iqueue */
1301                 if (FD_ISSET(in, rset)) {
1302                         char buf[4*4096];
1303                         len = read(in, buf, sizeof buf);
1304                         if (len == 0) {
1305                                 debug("read eof");
1306                                 cleanup_exit(0);
1307                         } else if (len < 0) {
1308                                 error("read: %s", strerror(errno));
1309                                 cleanup_exit(1);
1310                         } else {
1311                                 buffer_append(&iqueue, buf, len);
1312                         }
1313                 }
1314                 /* send oqueue to stdout */
1315                 if (FD_ISSET(out, wset)) {
1316                         len = write(out, buffer_ptr(&oqueue), olen);
1317                         if (len < 0) {
1318                                 error("write: %s", strerror(errno));
1319                                 cleanup_exit(1);
1320                         } else {
1321                                 buffer_consume(&oqueue, len);
1322                         }
1323                 }
1324                 /* process requests from client */
1325                 process();
1326         }
1327 }