receiver.c

Rsync 3.0.5 source code

/*
 * Routines only used by the receiving process.
 *
 * Copyright (C) 1996-2000 Andrew Tridgell
 * Copyright (C) 1996 Paul Mackerras
 * Copyright (C) 2003-2008 Wayne Davison
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, visit the http://fsf.org website.
 */

#include "rsync.h"

extern int verbose;
extern int dry_run;
extern int do_xfers;
extern int am_server;
extern int do_progress;
extern int inc_recurse;
extern int log_before_transfer;
extern int stdout_format_has_i;
extern int logfile_format_has_i;
extern int csum_length;
extern int read_batch;
extern int write_batch;
extern int batch_gen_fd;
extern int protocol_version;
extern int relative_paths;
extern int preserve_hard_links;
extern int preserve_perms;
extern int preserve_xattrs;
extern int basis_dir_cnt;
extern int make_backups;
extern int cleanup_got_literal;
extern int remove_source_files;
extern int append_mode;
extern int sparse_files;
extern int keep_partial;
extern int checksum_seed;
extern int inplace;
extern int delay_updates;
extern mode_t orig_umask;
extern struct stats stats;
extern char *tmpdir;
extern char *partial_dir;
extern char *basis_dir[];
extern struct file_list *cur_flist, *first_flist, *dir_flist;
extern struct filter_list_struct daemon_filter_list;

static struct bitbag *delayed_bits = NULL;
static int phase = 0, redoing = 0;
static flist_ndx_list batch_redo_list;
/* We're either updating the basis file or an identical copy: */
static int updating_basis_or_equiv;

/*
 * get_tmpname() - create a tmp filename for a given filename
 *
 *   If a tmpdir is defined, use that as the directory to
 *   put it in.  Otherwise, the tmp filename is in the same
 *   directory as the given name.  Note that there may be no
 *   directory at all in the given name!
 *
 *   The tmp filename is basically the given filename with a
 *   dot prepended, and .XXXXXX appended (for mkstemp() to
 *   put its unique gunk in).  Take care to not exceed
 *   either the MAXPATHLEN or NAME_MAX, esp. the last, as
 *   the basename basically becomes 8 chars longer. In that
 *   case, the original name is shortened sufficiently to
 *   make it all fit.
 *
 *   Of course, there's no real reason for the tmp name to
 *   look like the original, except to satisfy us humans.
 *   As long as it's unique, rsync will work.
 */

int get_tmpname(char *fnametmp, const char *fname)
{
	int maxname, added, length = 0;
	const char *f;

	if (tmpdir) {
		/* Note: this can't overflow, so the return value is safe */
		length = strlcpy(fnametmp, tmpdir, MAXPATHLEN - 2);
		fnametmp[length++] = '/';
	}

	if ((f = strrchr(fname, '/')) != NULL) {
		++f;
		if (!tmpdir) {
			length = f - fname;
			/* copy up to and including the slash */
			strlcpy(fnametmp, fname, length + 1);
		}
	} else
		f = fname;
	fnametmp[length++] = '.';

	/* The maxname value is bufsize, and includes space for the '\0'.
	 * (Note that NAME_MAX get -8 for the leading '.' above.) */
	maxname = MIN(MAXPATHLEN - 7 - length, NAME_MAX - 8);

	if (maxname < 1) {
		rprintf(FERROR_XFER, "temporary filename too long: %s\n", fname);
		fnametmp[0] = '\0';
		return 0;
	}

	added = strlcpy(fnametmp + length, f, maxname);
	if (added >= maxname)
		added = maxname - 1;
	memcpy(fnametmp + length + added, ".XXXXXX", 8);

	return 1;
}

/* Opens a temporary file for writing.
 * Success: Writes name into fnametmp, returns fd.
 * Failure: Clobbers fnametmp, returns -1.
 * Calling cleanup_set() is the caller's job. */
int open_tmpfile(char *fnametmp, const char *fname, struct file_struct *file)
{
	int fd;

	if (!get_tmpname(fnametmp, fname))
		return -1;

	/* We initially set the perms without the setuid/setgid bits or group
	 * access to ensure that there is no race condition.  They will be
	 * correctly updated after the right owner and group info is set.
	 * (Thanks to [e-mail] for pointing this out.) */
	fd = do_mkstemp(fnametmp, file->mode & INITACCESSPERMS);

#if 0
	/* In most cases parent directories will already exist because their
	 * information should have been previously transferred, but that may
	 * not be the case with -R */
	if (fd == -1 && relative_paths && errno == ENOENT
	    && create_directory_path(fnametmp) == 0) {
		/* Get back to name with XXXXXX in it. */
		get_tmpname(fnametmp, fname);
		fd = do_mkstemp(fnametmp, file->mode & INITACCESSPERMS);
	}
#endif

	if (fd == -1) {
		rsyserr(FERROR_XFER, errno, "mkstemp %s failed",
			full_fname(fnametmp));
		return -1;
	}

	return fd;
}

static int receive_data(int f_in, char *fname_r, int fd_r, OFF_T size_r,
			const char *fname, int fd, OFF_T total_size)
{
	static char file_sum1[MAX_DIGEST_LEN];
	static char file_sum2[MAX_DIGEST_LEN];
	struct map_struct *mapbuf;
	struct sum_struct sum;
	int32 len, sum_len;
	OFF_T offset = 0;
	OFF_T offset2;
	char *data;
	int32 i;
	char *map = NULL;

	read_sum_head(f_in, &sum);

	if (fd_r >= 0 && size_r > 0) {
		int32 read_size = MAX(sum.blength * 2, 16*1024);
		mapbuf = map_file(fd_r, size_r, read_size, sum.blength);
		if (verbose > 2) {
			rprintf(FINFO, "recv mapped %s of size %.0f\n",
				fname_r, (double)size_r);
		}
	} else
		mapbuf = NULL;

	sum_init(checksum_seed);

	if (append_mode > 0) {
		OFF_T j;
		sum.flength = (OFF_T)sum.count * sum.blength;
		if (sum.remainder)
			sum.flength -= sum.blength - sum.remainder;
		if (append_mode == 2) {
			for (j = CHUNK_SIZE; j < sum.flength; j += CHUNK_SIZE) {
				if (do_progress)
					show_progress(offset, total_size);
				sum_update(map_ptr(mapbuf, offset, CHUNK_SIZE),
					   CHUNK_SIZE);
				offset = j;
			}
			if (offset < sum.flength) {
				int32 len = (int32)(sum.flength - offset);
				if (do_progress)
					show_progress(offset, total_size);
				sum_update(map_ptr(mapbuf, offset, len), len);
			}
		}
		offset = sum.flength;
		if (fd != -1 && (j = do_lseek(fd, offset, SEEK_SET)) != offset) {
			rsyserr(FERROR_XFER, errno, "lseek of %s returned %.0f, not %.0f",
				full_fname(fname), (double)j, (double)offset);
			exit_cleanup(RERR_FILEIO);
		}
	}

	while ((i = recv_token(f_in, &data)) != 0) {
		if (do_progress)
			show_progress(offset, total_size);

		if (i > 0) {
			if (verbose > 3) {
				rprintf(FINFO,"data recv %d at %.0f\n",
					i,(double)offset);
			}

			stats.literal_data += i;
			cleanup_got_literal = 1;

			sum_update(data, i);

			if (fd != -1 && write_file(fd,data,i) != i)
				goto report_write_error;
			offset += i;
			continue;
		}

		i = -(i+1);
		offset2 = i * (OFF_T)sum.blength;
		len = sum.blength;
		if (i == (int)sum.count-1 && sum.remainder != 0)
			len = sum.remainder;

		stats.matched_data += len;

		if (verbose > 3) {
			rprintf(FINFO,
				"chunk[%d] of size %ld at %.0f offset=%.0f\n",
				i, (long)len, (double)offset2, (double)offset);
		}

		if (mapbuf) {
			map = map_ptr(mapbuf,offset2,len);

			see_token(map, len);
			sum_update(map, len);
		}

		if (updating_basis_or_equiv) {
			if (offset == offset2 && fd != -1) {
				OFF_T pos;
				if (flush_write_file(fd) < 0)
					goto report_write_error;
				offset += len;
				if ((pos = do_lseek(fd, len, SEEK_CUR)) != offset) {
					rsyserr(FERROR_XFER, errno,
						"lseek of %s returned %.0f, not %.0f",
						full_fname(fname),
						(double)pos, (double)offset);
					exit_cleanup(RERR_FILEIO);
				}
				continue;
			}
		}
		if (fd != -1 && map && write_file(fd, map, len) != (int)len)
			goto report_write_error;
		offset += len;
	}

	if (flush_write_file(fd) < 0)
		goto report_write_error;

#ifdef HAVE_FTRUNCATE
	if (inplace && fd != -1
	 && ftruncate(fd, offset) < 0) {
		rsyserr(FERROR_XFER, errno, "ftruncate failed on %s",
			full_fname(fname));
	}
#endif

	if (do_progress)
		end_progress(total_size);

	if (fd != -1 && offset > 0 && sparse_end(fd) != 0) {
	    report_write_error:
		rsyserr(FERROR_XFER, errno, "write failed on %s",
			full_fname(fname));
		exit_cleanup(RERR_FILEIO);
	}

	sum_len = sum_end(file_sum1);

	if (mapbuf)
		unmap_file(mapbuf);

	read_buf(f_in, file_sum2, sum_len);
	if (verbose > 2)
		rprintf(FINFO,"got file_sum\n");
	if (fd != -1 && memcmp(file_sum1, file_sum2, sum_len) != 0)
		return 0;
	return 1;
}


static void discard_receive_data(int f_in, OFF_T length)
{
	receive_data(f_in, NULL, -1, 0, NULL, -1, length);
}

static void handle_delayed_updates(char *local_name)
{
	char *fname, *partialptr;
	int ndx;

	for (ndx = -1; (ndx = bitbag_next_bit(delayed_bits, ndx)) >= 0; ) {
		struct file_struct *file = cur_flist->files[ndx];
		fname = local_name ? local_name : f_name(file, NULL);
		if ((partialptr = partial_dir_fname(fname)) != NULL) {
			if (make_backups > 0 && !make_backup(fname))
				continue;
			if (verbose > 2) {
				rprintf(FINFO, "renaming %s to %s\n",
					partialptr, fname);
			}
			/* We don't use robust_rename() here because the
			 * partial-dir must be on the same drive. */
			if (do_rename(partialptr, fname) < 0) {
				rsyserr(FERROR_XFER, errno,
					"rename failed for %s (from %s)",
					full_fname(fname), partialptr);
			} else {
				if (remove_source_files
				 || (preserve_hard_links && F_IS_HLINKED(file)))
					send_msg_int(MSG_SUCCESS, ndx);
				handle_partial_dir(partialptr, PDIR_DELETE);
			}
		}
	}
}

static void no_batched_update(int ndx, BOOL is_redo)
{
	struct file_list *flist = flist_for_ndx(ndx, "no_batched_update");
	struct file_struct *file = flist->files[ndx - flist->ndx_start];

	rprintf(FERROR_XFER, "(No batched update for%s \"%s\")\n",
		is_redo ? " resend of" : "", f_name(file, NULL));

	if (inc_recurse)
		send_msg_int(MSG_NO_SEND, ndx);
}

static int we_want_redo(int desired_ndx)
{
	static int redo_ndx = -1;

	while (redo_ndx < desired_ndx) {
		if (redo_ndx >= 0)
			no_batched_update(redo_ndx, True);
		if ((redo_ndx = flist_ndx_pop(&batch_redo_list)) < 0)
			return 0;
	}

	if (redo_ndx == desired_ndx) {
		redo_ndx = -1;
		return 1;
	}

	return 0;
}

static int gen_wants_ndx(int desired_ndx)
{
	static int next_ndx = -1;
	static BOOL got_eof = 0;

	if (got_eof)
		return 0;

	while (next_ndx < desired_ndx) {
		if (next_ndx >= 0)
			no_batched_update(next_ndx, False);
		if ((next_ndx = read_int(batch_gen_fd)) < 0) {
			got_eof = True;
			return 0;
		}
	}

	if (next_ndx == desired_ndx) {
		next_ndx = -1;
		return 1;
	}