Allow basic connectivity check via rrsync

[rsync.git] / receiver.c

/*
 * Routines only used by the receiving process.
 *
 * Copyright (C) 1996-2000 Andrew Tridgell
 * Copyright (C) 1996 Paul Mackerras
 * Copyright (C) 2003-2023 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"
#include "inums.h"

extern int dry_run;
extern int do_xfers;
extern int am_root;
extern int am_server;
extern int inc_recurse;
extern int log_before_transfer;
extern int stdout_format_has_i;
extern int logfile_format_has_i;
extern int want_xattr_optim;
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 write_devices;
extern int preserve_xattrs;
extern int do_fsync;
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 preallocate_files;
extern int keep_partial;
extern int checksum_seed;
extern int whole_file;
extern int inplace;
extern int inplace_partial;
extern int allowed_lull;
extern int delay_updates;
extern BOOL want_progress_now;
extern mode_t orig_umask;
extern struct stats stats;
extern char *tmpdir;
extern char *partial_dir;
extern char *basis_dir[MAX_BASIS_DIRS+1];
extern char sender_file_sum[MAX_DIGEST_LEN];
extern struct file_list *cur_flist, *first_flist, *dir_flist;
extern filter_rule_list daemon_filter_list;
extern OFF_T preallocated_len;

extern struct name_num_item *xfer_sum_nni;
extern int xfer_sum_len;

static struct bitbag *delayed_bits = NULL;
static int phase = 0, redoing = 0;
static flist_ndx_list batch_redo_list;
/* This is non-0 when we are updating the basis file or an identical copy: */
static int updating_basis_or_equiv;

#define TMPNAME_SUFFIX ".XXXXXX"
#define TMPNAME_SUFFIX_LEN ((int)sizeof TMPNAME_SUFFIX - 1)
#define MAX_UNIQUE_NUMBER 999999
#define MAX_UNIQUE_LOOP 100

/* 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).  We take care
 * to not exceed either the MAXPATHLEN or NAME_MAX, especially the last, as
 * the basename basically becomes 8 characters longer.  In such a case, the
 * original name is shortened sufficiently to make it all fit.
 *
 * If the make_unique arg is True, the XXXXXX string is replaced with a unique
 * string that doesn't exist at the time of the check.  This is intended to be
 * used for creating hard links, symlinks, devices, and special files, since
 * normal files should be handled by mkstemp() for safety.
 *
 * Of course, the only reason the file is based on the original name is to
 * make it easier to figure out what purpose a temp file is serving when a
 * transfer is in progress. */
int get_tmpname(char *fnametmp, const char *fname, BOOL make_unique)
{
        int maxname, length = 0;
        const char *f;
        char *suf;

        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;

        if (!tmpdir) { /* using a tmpdir avoids the leading dot on our temp names */
                if (*f == '.') /* avoid an extra leading dot for OS X's sake */
                        f++;
                fnametmp[length++] = '.';
        }

        /* The maxname value is bufsize, and includes space for the '\0'.
         * NAME_MAX needs an extra -1 for the name's leading dot. */
        maxname = MIN(MAXPATHLEN - length - TMPNAME_SUFFIX_LEN,
                      NAME_MAX - 1 - TMPNAME_SUFFIX_LEN);

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

        if (maxname) {
                int added = strlcpy(fnametmp + length, f, maxname);
                if (added >= maxname)
                        added = maxname - 1;
                suf = fnametmp + length + added;

                /* Trim any dangling high-bit chars if the first-trimmed char (if any) is
                 * also a high-bit char, just in case we cut into a multi-byte sequence.
                 * We are guaranteed to stop because of the leading '.' we added. */
                if ((int)f[added] & 0x80) {
                        while ((int)suf[-1] & 0x80)
                                suf--;
                }
                /* trim one trailing dot before our suffix's dot */
                if (suf[-1] == '.')
                        suf--;
        } else
                suf = fnametmp + length - 1; /* overwrite the leading dot with suffix's dot */

        if (make_unique) {
                static unsigned counter_limit;
                unsigned counter;

                if (!counter_limit) {
                        counter_limit = (unsigned)getpid() + MAX_UNIQUE_LOOP;
                        if (counter_limit > MAX_UNIQUE_NUMBER || counter_limit < MAX_UNIQUE_LOOP)
                                counter_limit = MAX_UNIQUE_LOOP;
                }
                counter = counter_limit - MAX_UNIQUE_LOOP;

                /* This doesn't have to be very good because we don't need
                 * to worry about someone trying to guess the values:  all
                 * a conflict will do is cause a device, special file, hard
                 * link, or symlink to fail to be created.  Also: avoid
                 * using mktemp() due to gcc's annoying warning. */
                while (1) {
                        snprintf(suf, TMPNAME_SUFFIX_LEN+1, ".%d", counter);
                        if (access(fnametmp, 0) < 0)
                                break;
                        if (++counter >= counter_limit)
                                return 0;
                }
        } else
                memcpy(suf, TMPNAME_SUFFIX, TMPNAME_SUFFIX_LEN+1);

        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;
        mode_t added_perms;

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

        if (am_root < 0) {
                /* For --fake-super, the file must be useable by the copying
                 * user, just like it would be for root. */
                added_perms = S_IRUSR|S_IWUSR;
        } else {
                /* For a normal copy, we need to be able to tweak things like xattrs. */
                added_perms = S_IWUSR;
        }

        /* 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 snabb@epipe.fi for pointing this out.) */
        fd = do_mkstemp(fnametmp, (file->mode|added_perms) & 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
         && make_path(fnametmp, MKP_SKIP_SLASH | MKP_DROP_NAME) == 0) {
                /* Get back to name with XXXXXX in it. */
                get_tmpname(fnametmp, fname, False);
                fd = do_mkstemp(fnametmp, (file->mode|added_perms) & 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, struct file_struct *file, int inplace_sizing)
{
        static char file_sum1[MAX_DIGEST_LEN];
        struct map_struct *mapbuf;
        struct sum_struct sum;
        int32 len;
        OFF_T total_size = F_LENGTH(file);
        OFF_T offset = 0;
        OFF_T offset2;
        char *data;
        int32 i;
        char *map = NULL;

#ifdef SUPPORT_PREALLOCATION
        if (preallocate_files && fd != -1 && total_size > 0 && (!inplace_sizing || total_size > size_r)) {
                /* Try to preallocate enough space for file's eventual length.  Can
                 * reduce fragmentation on filesystems like ext4, xfs, and NTFS. */
                if ((preallocated_len = do_fallocate(fd, 0, total_size)) < 0)
                        rsyserr(FWARNING, errno, "do_fallocate %s", full_fname(fname));
        } else
#endif
        if (inplace_sizing) {
#ifdef HAVE_FTRUNCATE
                /* The most compatible way to create a sparse file is to start with no length. */
                if (sparse_files > 0 && whole_file && fd >= 0 && do_ftruncate(fd, 0) == 0)
                        preallocated_len = 0;
                else
#endif
                        preallocated_len = size_r;
        } else
                preallocated_len = 0;

        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 (DEBUG_GTE(DELTASUM, 2)) {
                        rprintf(FINFO, "recv mapped %s of size %s\n",
                                fname_r, big_num(size_r));
                }
        } else
                mapbuf = NULL;

        sum_init(xfer_sum_nni, 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 && mapbuf) {
                        for (j = CHUNK_SIZE; j < sum.flength; j += CHUNK_SIZE) {
                                if (INFO_GTE(PROGRESS, 1))
                                        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 (INFO_GTE(PROGRESS, 1))
                                        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 %s, not %s",
                                full_fname(fname), big_num(j), big_num(offset));
                        exit_cleanup(RERR_FILEIO);
                }
        }

        while ((i = recv_token(f_in, &data)) != 0) {
                if (INFO_GTE(PROGRESS, 1))
                        show_progress(offset, total_size);

                if (allowed_lull)
                        maybe_send_keepalive(time(NULL), MSK_ALLOW_FLUSH | MSK_ACTIVE_RECEIVER);

                if (i > 0) {
                        if (DEBUG_GTE(DELTASUM, 3)) {
                                rprintf(FINFO,"data recv %d at %s\n",
                                        i, big_num(offset));
                        }

                        stats.literal_data += i;
                        cleanup_got_literal = 1;

                        sum_update(data, i);

                        if (fd != -1 && write_file(fd, 0, offset, 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 (DEBUG_GTE(DELTASUM, 3)) {
                        rprintf(FINFO,
                                "chunk[%d] of size %ld at %s offset=%s%s\n",
                                i, (long)len, big_num(offset2), big_num(offset),
                                updating_basis_or_equiv && offset == offset2 ? " (seek)" : "");
                }

                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) {
                                if (skip_matched(fd, offset, map, len) < 0)
                                        goto report_write_error;
                                offset += len;
                                continue;
                        }
                }
                if (fd != -1 && map && write_file(fd, 0, offset, map, len) != (int)len)
                        goto report_write_error;
                offset += len;
        }

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

#ifdef HAVE_FTRUNCATE
        /* inplace: New data could be shorter than old data.
         * preallocate_files: total_size could have been an overestimate.
         *     Cut off any extra preallocated zeros from dest file. */
        if ((inplace_sizing || preallocated_len > offset) && fd != -1 && !IS_DEVICE(file->mode)) {
                if (do_ftruncate(fd, offset) < 0)
                        rsyserr(FERROR_XFER, errno, "ftruncate failed on %s", full_fname(fname));
        }
#endif

        if (INFO_GTE(PROGRESS, 1))
                end_progress(total_size);

        sum_end(file_sum1);

        if (do_fsync && fd != -1 && fsync(fd) != 0) {
                rsyserr(FERROR, errno, "fsync failed on %s", full_fname(fname));
                exit_cleanup(RERR_FILEIO);
        }

        if (mapbuf)
                unmap_file(mapbuf);

        read_buf(f_in, sender_file_sum, xfer_sum_len);
        if (DEBUG_GTE(DELTASUM, 2))
                rprintf(FINFO,"got file_sum\n");
        if (fd != -1 && memcmp(file_sum1, sender_file_sum, xfer_sum_len) != 0)
                return 0;
        return 1;
}


static void discard_receive_data(int f_in, struct file_struct *file)
{
        receive_data(f_in, NULL, -1, 0, NULL, -1, file, 0);
}

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, False))
                                continue;
                        if (DEBUG_GTE(RECV, 1)) {
                                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_success(fname, 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 && !dry_run)
                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, int flist_num)
{
        static int next_ndx = -1;
        static int done_cnt = 0;
        static BOOL got_eof = False;

        if (got_eof)
                return 0;

        /* TODO: integrate gen-reading I/O into perform_io() so this is not needed? */
        io_flush(FULL_FLUSH);

        while (next_ndx < desired_ndx) {
                if (inc_recurse && flist_num <= done_cnt)
                        return 0;
                if (next_ndx >= 0)
                        no_batched_update(next_ndx, False);
                if ((next_ndx = read_int(batch_gen_fd)) < 0) {
                        if (inc_recurse) {
                                done_cnt++;
                                continue;
                        }
                        got_eof = True;
                        return 0;
                }
        }

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

        return 0;
}

/**
 * main routine for receiver process.
 *
 * Receiver process runs on the same host as the generator process. */
int recv_files(int f_in, int f_out, char *local_name)
{
        int fd1,fd2;
        STRUCT_STAT st;
        int iflags, xlen;
        char *fname, fbuf[MAXPATHLEN];
        char xname[MAXPATHLEN];
        char *fnametmp, fnametmpbuf[MAXPATHLEN];
        char *fnamecmp, *partialptr;
        char fnamecmpbuf[MAXPATHLEN];
        uchar fnamecmp_type;
        struct file_struct *file;
        int itemizing = am_server ? logfile_format_has_i : stdout_format_has_i;
        enum logcode log_code = log_before_transfer ? FLOG : FINFO;
        int max_phase = protocol_version >= 29 ? 2 : 1;
        int dflt_perms = (ACCESSPERMS & ~orig_umask);
#ifdef SUPPORT_ACLS
        const char *parent_dirname = "";
#endif
        int ndx, recv_ok, one_inplace;

        if (DEBUG_GTE(RECV, 1))
                rprintf(FINFO, "recv_files(%d) starting\n", cur_flist->used);

        if (delay_updates)
                delayed_bits = bitbag_create(cur_flist->used + 1);

        if (whole_file < 0)
                whole_file = 0;

        progress_init();

        while (1) {
                cleanup_disable();

                /* This call also sets cur_flist. */
                ndx = read_ndx_and_attrs(f_in, f_out, &iflags, &fnamecmp_type,
                                         xname, &xlen);
                if (ndx == NDX_DONE) {
                        if (!am_server && cur_flist) {
                                set_current_file_index(NULL, 0);
                                if (INFO_GTE(PROGRESS, 2))
                                        end_progress(0);
                        }
                        if (inc_recurse && first_flist) {
                                if (read_batch) {
                                        ndx = first_flist->used + first_flist->ndx_start;
                                        gen_wants_ndx(ndx, first_flist->flist_num);
                                }
                                flist_free(first_flist);
                                if (first_flist)
                                        continue;
                        } else if (read_batch && first_flist) {
                                ndx = first_flist->used;
                                gen_wants_ndx(ndx, first_flist->flist_num);
                        }
                        if (++phase > max_phase)
                                break;
                        if (DEBUG_GTE(RECV, 1))
                                rprintf(FINFO, "recv_files phase=%d\n", phase);
                        if (phase == 2 && delay_updates)
                                handle_delayed_updates(local_name);
                        write_int(f_out, NDX_DONE);
                        continue;
                }

                if (ndx - cur_flist->ndx_start >= 0)
                        file = cur_flist->files[ndx - cur_flist->ndx_start];
                else
                        file = dir_flist->files[cur_flist->parent_ndx];
                fname = local_name ? local_name : f_name(file, fbuf);

                if (DEBUG_GTE(RECV, 1))
                        rprintf(FINFO, "recv_files(%s)\n", fname);

                if (daemon_filter_list.head && (*fname != '.' || fname[1] != '\0')) {
                        int filt_flags = S_ISDIR(file->mode) ? NAME_IS_DIR : NAME_IS_FILE;
                        if (check_filter(&daemon_filter_list, FLOG, fname, filt_flags) < 0) {
                                rprintf(FERROR, "ERROR: rejecting file transfer request for daemon excluded file: %s\n",
                                        fname);
                                exit_cleanup(RERR_PROTOCOL);
                        }
                }

#ifdef SUPPORT_XATTRS
                if (preserve_xattrs && iflags & ITEM_REPORT_XATTR && do_xfers
                 && !(want_xattr_optim && BITS_SET(iflags, ITEM_XNAME_FOLLOWS|ITEM_LOCAL_CHANGE)))
                        recv_xattr_request(file, f_in);
#endif

                if (!(iflags & ITEM_TRANSFER)) {
                        maybe_log_item(file, iflags, itemizing, xname);
#ifdef SUPPORT_XATTRS
                        if (preserve_xattrs && iflags & ITEM_REPORT_XATTR && do_xfers
                         && !BITS_SET(iflags, ITEM_XNAME_FOLLOWS|ITEM_LOCAL_CHANGE))
                                set_file_attrs(fname, file, NULL, fname, 0);
#endif
                        if (iflags & ITEM_IS_NEW) {
                                stats.created_files++;
                                if (S_ISREG(file->mode)) {
                                        /* Nothing further to count. */
                                } else if (S_ISDIR(file->mode))
                                        stats.created_dirs++;
#ifdef SUPPORT_LINKS
                                else if (S_ISLNK(file->mode))
                                        stats.created_symlinks++;
#endif
                                else if (IS_DEVICE(file->mode))
                                        stats.created_devices++;
                                else
                                        stats.created_specials++;
                        }
                        continue;
                }
                if (phase == 2) {
                        rprintf(FERROR,
                                "got transfer request in phase 2 [%s]\n",
                                who_am_i());
                        exit_cleanup(RERR_PROTOCOL);
                }

                if (file->flags & FLAG_FILE_SENT) {
                        if (csum_length == SHORT_SUM_LENGTH) {
                                if (keep_partial && !partial_dir)
                                        make_backups = -make_backups; /* prevents double backup */
                                if (append_mode)
                                        sparse_files = -sparse_files;
                                append_mode = -append_mode;
                                csum_length = SUM_LENGTH;
                                redoing = 1;
                        }
                } else {
                        if (csum_length != SHORT_SUM_LENGTH) {
                                if (keep_partial && !partial_dir)
                                        make_backups = -make_backups;
                                if (append_mode)
                                        sparse_files = -sparse_files;
                                append_mode = -append_mode;
                                csum_length = SHORT_SUM_LENGTH;
                                redoing = 0;
                        }
                        if (iflags & ITEM_IS_NEW)
                                stats.created_files++;
                }

                if (!am_server)
                        set_current_file_index(file, ndx);
                stats.xferred_files++;
                stats.total_transferred_size += F_LENGTH(file);

                cleanup_got_literal = 0;

                if (read_batch) {
                        int wanted = redoing
                                   ? we_want_redo(ndx)
                                   : gen_wants_ndx(ndx, cur_flist->flist_num);
                        if (!wanted) {
                                rprintf(FINFO,
                                        "(Skipping batched update for%s \"%s\")\n",
                                        redoing ? " resend of" : "",
                                        fname);
                                discard_receive_data(f_in, file);
                                file->flags |= FLAG_FILE_SENT;
                                continue;
                        }
                }

                remember_initial_stats();

                if (!do_xfers) { /* log the transfer */
                        log_item(FCLIENT, file, iflags, NULL);
                        if (read_batch)
                                discard_receive_data(f_in, file);
                        continue;
                }
                if (write_batch < 0) {
                        log_item(FCLIENT, file, iflags, NULL);
                        if (!am_server)
                                discard_receive_data(f_in, file);
                        if (inc_recurse)
                                send_msg_success(fname, ndx);
                        continue;
                }

                partialptr = partial_dir ? partial_dir_fname(fname) : fname;

                if (protocol_version >= 29) {
                        switch (fnamecmp_type) {
                        case FNAMECMP_FNAME:
                                fnamecmp = fname;
                                break;
                        case FNAMECMP_PARTIAL_DIR:
                                fnamecmp = partialptr;
                                break;
                        case FNAMECMP_BACKUP:
                                fnamecmp = get_backup_name(fname);
                                break;
                        case FNAMECMP_FUZZY:
                                if (file->dirname) {
                                        pathjoin(fnamecmpbuf, sizeof fnamecmpbuf, file->dirname, xname);
                                        fnamecmp = fnamecmpbuf;
                                } else
                                        fnamecmp = xname;
                                break;
                        default:
                                if (fnamecmp_type > FNAMECMP_FUZZY && fnamecmp_type-FNAMECMP_FUZZY <= basis_dir_cnt) {
                                        fnamecmp_type -= FNAMECMP_FUZZY + 1;
                                        if (file->dirname) {
                                                stringjoin(fnamecmpbuf, sizeof fnamecmpbuf,
                                                           basis_dir[fnamecmp_type], "/", file->dirname, "/", xname, NULL);
                                        } else
                                                pathjoin(fnamecmpbuf, sizeof fnamecmpbuf, basis_dir[fnamecmp_type], xname);
                                } else if (fnamecmp_type >= basis_dir_cnt) {
                                        rprintf(FERROR,
                                                "invalid basis_dir index: %d.\n",
                                                fnamecmp_type);
                                        exit_cleanup(RERR_PROTOCOL);
                                } else
                                        pathjoin(fnamecmpbuf, sizeof fnamecmpbuf, basis_dir[fnamecmp_type], fname);
                                fnamecmp = fnamecmpbuf;
                                break;
                        }
                        if (!fnamecmp || (daemon_filter_list.head
                          && check_filter(&daemon_filter_list, FLOG, fnamecmp, 0) < 0)) {
                                fnamecmp = fname;
                                fnamecmp_type = FNAMECMP_FNAME;
                        }
                } else {
                        /* Reminder: --inplace && --partial-dir are never
                         * enabled at the same time. */
                        if (inplace && make_backups > 0) {
                                if (!(fnamecmp = get_backup_name(fname)))
                                        fnamecmp = fname;
                                else
                                        fnamecmp_type = FNAMECMP_BACKUP;
                        } else if (partial_dir && partialptr)
                                fnamecmp = partialptr;
                        else
                                fnamecmp = fname;
                }

                /* open the file */
                fd1 = do_open(fnamecmp, O_RDONLY, 0);

                if (fd1 == -1 && protocol_version < 29) {
                        if (fnamecmp != fname) {
                                fnamecmp = fname;
                                fnamecmp_type = FNAMECMP_FNAME;
                                fd1 = do_open(fnamecmp, O_RDONLY, 0);
                        }

                        if (fd1 == -1 && basis_dir[0]) {
                                /* pre-29 allowed only one alternate basis */
                                pathjoin(fnamecmpbuf, sizeof fnamecmpbuf,
                                         basis_dir[0], fname);
                                fnamecmp = fnamecmpbuf;
                                fnamecmp_type = FNAMECMP_BASIS_DIR_LOW;
                                fd1 = do_open(fnamecmp, O_RDONLY, 0);
                        }
                }

                one_inplace = inplace_partial && fnamecmp_type == FNAMECMP_PARTIAL_DIR;
                updating_basis_or_equiv = one_inplace
                    || (inplace && (fnamecmp == fname || fnamecmp_type == FNAMECMP_BACKUP));

                if (fd1 == -1) {
                        st.st_mode = 0;
                        st.st_size = 0;
                } else if (do_fstat(fd1,&st) != 0) {
                        rsyserr(FERROR_XFER, errno, "fstat %s failed",
                                full_fname(fnamecmp));
                        discard_receive_data(f_in, file);
                        close(fd1);
                        if (inc_recurse)
                                send_msg_int(MSG_NO_SEND, ndx);
                        continue;
                }

                if (fd1 != -1 && S_ISDIR(st.st_mode) && fnamecmp == fname) {
                        /* this special handling for directories
                         * wouldn't be necessary if robust_rename()
                         * and the underlying robust_unlink could cope
                         * with directories
                         */
                        rprintf(FERROR_XFER, "recv_files: %s is a directory\n",
                                full_fname(fnamecmp));
                        discard_receive_data(f_in, file);
                        close(fd1);
                        if (inc_recurse)
                                send_msg_int(MSG_NO_SEND, ndx);
                        continue;
                }

                if (write_devices && IS_DEVICE(st.st_mode)) {
                        if (fd1 != -1 && st.st_size == 0)
                                st.st_size = get_device_size(fd1, fname);
                        /* Mark the file entry as a device so that we don't try to truncate it later on. */
                        file->mode = S_IFBLK | (file->mode & ACCESSPERMS);
                } else if (fd1 != -1 && !(S_ISREG(st.st_mode))) {
                        close(fd1);
                        fd1 = -1;
                }

                /* If we're not preserving permissions, change the file-list's
                 * mode based on the local permissions and some heuristics. */
                if (!preserve_perms) {
                        int exists = fd1 != -1;
#ifdef SUPPORT_ACLS
                        const char *dn = file->dirname ? file->dirname : ".";
                        if (parent_dirname != dn
                         && strcmp(parent_dirname, dn) != 0) {
                                dflt_perms = default_perms_for_dir(dn);
                                parent_dirname = dn;
                        }
#endif
                        file->mode = dest_mode(file->mode, st.st_mode, dflt_perms, exists);
                }

                /* We now check to see if we are writing the file "inplace" */
                if (inplace || one_inplace)  {
                        fnametmp = one_inplace ? partialptr : fname;
                        fd2 = do_open(fnametmp, O_WRONLY|O_CREAT, 0600);
#ifdef linux
                        if (fd2 == -1 && errno == EACCES) {
                                /* Maybe the error was due to protected_regular setting? */
                                fd2 = do_open(fname, O_WRONLY, 0600);
                        }
#endif
                        if (fd2 == -1) {
                                rsyserr(FERROR_XFER, errno, "open %s failed",
                                        full_fname(fnametmp));
                        } else if (updating_basis_or_equiv)
                                cleanup_set(NULL, NULL, file, fd1, fd2);
                } else {
                        fnametmp = fnametmpbuf;
                        fd2 = open_tmpfile(fnametmp, fname, file);
                        if (fd2 != -1)
                                cleanup_set(fnametmp, partialptr, file, fd1, fd2);
                }

                if (fd2 == -1) {
                        discard_receive_data(f_in, file);
                        if (fd1 != -1)
                                close(fd1);
                        if (inc_recurse)
                                send_msg_int(MSG_NO_SEND, ndx);
                        continue;
                }

                /* log the transfer */
                if (log_before_transfer)
                        log_item(FCLIENT, file, iflags, NULL);
                else if (!am_server && INFO_GTE(NAME, 1) && INFO_EQ(PROGRESS, 1))
                        rprintf(FINFO, "%s\n", fname);

                /* recv file data */
                recv_ok = receive_data(f_in, fnamecmp, fd1, st.st_size, fname, fd2, file, inplace || one_inplace);

                log_item(log_code, file, iflags, NULL);
                if (want_progress_now)
                        instant_progress(fname);

                if (fd1 != -1)
                        close(fd1);
                if (close(fd2) < 0) {
                        rsyserr(FERROR, errno, "close failed on %s",
                                full_fname(fnametmp));
                        exit_cleanup(RERR_FILEIO);
                }

                if ((recv_ok && (!delay_updates || !partialptr)) || inplace) {
                        if (partialptr == fname)
                                partialptr = NULL;
                        if (!finish_transfer(fname, fnametmp, fnamecmp, partialptr, file, recv_ok, 1))
                                recv_ok = -1;
                        else if (fnamecmp == partialptr) {
                                if (!one_inplace)
                                        do_unlink(partialptr);
                                handle_partial_dir(partialptr, PDIR_DELETE);
                        }
                } else if (keep_partial && partialptr && (!one_inplace || delay_updates)) {
                        if (!handle_partial_dir(partialptr, PDIR_CREATE)) {
                                rprintf(FERROR,
                                        "Unable to create partial-dir for %s -- discarding %s.\n",
                                        local_name ? local_name : f_name(file, NULL),
                                        recv_ok ? "completed file" : "partial file");
                                do_unlink(fnametmp);
                                recv_ok = -1;
                        } else if (!finish_transfer(partialptr, fnametmp, fnamecmp, NULL,
                                                    file, recv_ok, !partial_dir))
                                recv_ok = -1;
                        else if (delay_updates && recv_ok) {
                                bitbag_set_bit(delayed_bits, ndx);
                                recv_ok = 2;
                        } else
                                partialptr = NULL;
                } else if (!one_inplace)
                        do_unlink(fnametmp);

                cleanup_disable();

                if (read_batch)
                        file->flags |= FLAG_FILE_SENT;

                switch (recv_ok) {
                case 2:
                        break;
                case 1:
                        if (remove_source_files || inc_recurse || (preserve_hard_links && F_IS_HLINKED(file)))
                                send_msg_success(fname, ndx);
                        break;
                case 0: {
                        enum logcode msgtype = redoing ? FERROR_XFER : FWARNING;
                        if (msgtype == FERROR_XFER || INFO_GTE(NAME, 1) || stdout_format_has_i) {
                                char *errstr, *redostr, *keptstr;
                                if (!(keep_partial && partialptr) && !inplace)
                                        keptstr = "discarded";
                                else if (partial_dir)
                                        keptstr = "put into partial-dir";
                                else
                                        keptstr = "retained";
                                if (msgtype == FERROR_XFER) {
                                        errstr = "ERROR";
                                        redostr = "";
                                } else {
                                        errstr = "WARNING";
                                        redostr = read_batch ? " (may try again)"
                                                             : " (will try again)";
                                }
                                rprintf(msgtype,
                                        "%s: %s failed verification -- update %s%s.\n",
                                        errstr, local_name ? f_name(file, NULL) : fname,
                                        keptstr, redostr);
                        }
                        if (!redoing) {
                                if (read_batch)
                                        flist_ndx_push(&batch_redo_list, ndx);
                                send_msg_int(MSG_REDO, ndx);
                                file->flags |= FLAG_FILE_SENT;
                        } else if (inc_recurse)
                                send_msg_int(MSG_NO_SEND, ndx);
                        break;
                }
                case -1:
                        if (inc_recurse)
                                send_msg_int(MSG_NO_SEND, ndx);
                        break;
                }
        }
        if (make_backups < 0)
                make_backups = -make_backups;

        if (phase == 2 && delay_updates) /* for protocol_version < 29 */
                handle_delayed_updates(local_name);

        if (DEBUG_GTE(RECV, 1))
                rprintf(FINFO,"recv_files finished\n");

        return 0;
}