Switch the checking of preserve_[ug]id var to checking [ug]id_ndx var

[rsync/rsync.git] / flist.c

/*
 * Generate and receive file lists.
 *
 * Copyright (C) 1996 Andrew Tridgell
 * Copyright (C) 1996 Paul Mackerras
 * Copyright (C) 2001, 2002 Martin Pool <mbp@samba.org>
 * Copyright (C) 2002-2007 Wayne Davison
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include "rsync.h"
#include "rounding.h"
#include "io.h"

extern int verbose;
extern int list_only;
extern int am_root;
extern int am_server;
extern int am_daemon;
extern int am_sender;
extern int am_generator;
extern int inc_recurse;
extern int do_progress;
extern int always_checksum;
extern int module_id;
extern int ignore_errors;
extern int numeric_ids;
extern int recurse;
extern int use_qsort;
extern int xfer_dirs;
extern int filesfrom_fd;
extern int one_file_system;
extern int copy_dirlinks;
extern int keep_dirlinks;
extern int preserve_acls;
extern int preserve_xattrs;
extern int preserve_links;
extern int preserve_hard_links;
extern int preserve_devices;
extern int preserve_specials;
extern int uid_ndx;
extern int gid_ndx;
extern int relative_paths;
extern int implied_dirs;
extern int file_extra_cnt;
extern int ignore_perishable;
extern int non_perishable_cnt;
extern int prune_empty_dirs;
extern int copy_links;
extern int copy_unsafe_links;
extern int protocol_version;
extern int sanitize_paths;
extern struct stats stats;

extern char curr_dir[MAXPATHLEN];

extern struct chmod_mode_struct *chmod_modes;

extern struct filter_list_struct filter_list;
extern struct filter_list_struct server_filter_list;

#ifdef ICONV_OPTION
extern int ic_ndx;
extern int need_unsorted_flist;
extern iconv_t ic_send, ic_recv;
#endif

#define PTR_SIZE (sizeof (struct file_struct *))

int io_error;
int checksum_len;
dev_t filesystem_dev; /* used to implement -x */

struct file_list *cur_flist, *first_flist, *dir_flist;
int send_dir_ndx = -1, send_dir_depth = 0;
int flist_cnt = 0; /* how many (non-tmp) file list objects exist */
int file_total = 0; /* total of all active items over all file-lists */
int flist_eof = 0; /* all the file-lists are now known */

/* The tmp_* vars are used as a cache area by make_file() to store data
 * that the sender doesn't need to remember in its file list.  The data
 * will survive just long enough to be used by send_file_entry(). */
static dev_t tmp_rdev;
#ifdef SUPPORT_HARD_LINKS
static int64 tmp_dev, tmp_ino;
#endif
static char tmp_sum[MAX_DIGEST_LEN];

static char empty_sum[MAX_DIGEST_LEN];
static int flist_count_offset; /* for --delete --progress */
static int dir_count = 0;

static void clean_flist(struct file_list *flist, int strip_root);
static void output_flist(struct file_list *flist);

void init_flist(void)
{
        if (verbose > 4) {
                rprintf(FINFO, "FILE_STRUCT_LEN=%d, EXTRA_LEN=%d\n",
                        (int)FILE_STRUCT_LEN, (int)EXTRA_LEN);
        }
        checksum_len = protocol_version < 21 ? 2
                     : protocol_version < 30 ? MD4_DIGEST_LEN
                     : MD5_DIGEST_LEN;
}

static int show_filelist_p(void)
{
        return verbose && xfer_dirs && !am_server && !inc_recurse;
}

static void start_filelist_progress(char *kind)
{
        rprintf(FCLIENT, "%s ... ", kind);
        if (verbose > 1 || do_progress)
                rprintf(FCLIENT, "\n");
        rflush(FINFO);
}

static void emit_filelist_progress(int count)
{
        rprintf(FCLIENT, " %d files...\r", count);
}

static void maybe_emit_filelist_progress(int count)
{
        if (do_progress && show_filelist_p() && (count % 100) == 0)
                emit_filelist_progress(count);
}

static void finish_filelist_progress(const struct file_list *flist)
{
        if (do_progress) {
                /* This overwrites the progress line */
                rprintf(FINFO, "%d file%sto consider\n",
                        flist->count, flist->count == 1 ? " " : "s ");
        } else
                rprintf(FINFO, "done\n");
}

void show_flist_stats(void)
{
        /* Nothing yet */
}

static void list_file_entry(struct file_struct *f)
{
        char permbuf[PERMSTRING_SIZE];
        double len;

        if (!F_IS_ACTIVE(f)) {
                /* this can happen if duplicate names were removed */
                return;
        }

        permstring(permbuf, f->mode);
        len = F_LENGTH(f);

        /* TODO: indicate '+' if the entry has an ACL. */

#ifdef SUPPORT_LINKS
        if (preserve_links && S_ISLNK(f->mode)) {
                rprintf(FINFO, "%s %11.0f %s %s -> %s\n",
                        permbuf, len, timestring(f->modtime),
                        f_name(f, NULL), F_SYMLINK(f));
        } else
#endif
        {
                rprintf(FINFO, "%s %11.0f %s %s\n",
                        permbuf, len, timestring(f->modtime),
                        f_name(f, NULL));
        }
}

/* Stat either a symlink or its referent, depending on the settings of
 * copy_links, copy_unsafe_links, etc.  Returns -1 on error, 0 on success.
 *
 * If path is the name of a symlink, then the linkbuf buffer (which must hold
 * MAXPATHLEN chars) will be set to the symlink's target string.
 *
 * The stat structure pointed to by stp will contain information about the
 * link or the referent as appropriate, if they exist. */
static int readlink_stat(const char *path, STRUCT_STAT *stp, char *linkbuf)
{
#ifdef SUPPORT_LINKS
        if (link_stat(path, stp, copy_dirlinks) < 0)
                return -1;
        if (S_ISLNK(stp->st_mode)) {
                int llen = readlink(path, linkbuf, MAXPATHLEN - 1);
                if (llen < 0)
                        return -1;
                linkbuf[llen] = '\0';
                if (copy_unsafe_links && unsafe_symlink(linkbuf, path)) {
                        if (verbose > 1) {
                                rprintf(FINFO,"copying unsafe symlink \"%s\" -> \"%s\"\n",
                                        path, linkbuf);
                        }
                        return x_stat(path, stp, NULL);
                }
        }
        return 0;
#else
        return x_stat(path, stp, NULL);
#endif
}

int link_stat(const char *path, STRUCT_STAT *stp, int follow_dirlinks)
{
#ifdef SUPPORT_LINKS
        if (copy_links)
                return x_stat(path, stp, NULL);
        if (x_lstat(path, stp, NULL) < 0)
                return -1;
        if (follow_dirlinks && S_ISLNK(stp->st_mode)) {
                STRUCT_STAT st;
                if (x_stat(path, &st, NULL) == 0 && S_ISDIR(st.st_mode))
                        *stp = st;
        }
        return 0;
#else
        return x_stat(path, stp, NULL);
#endif
}

/* This function is used to check if a file should be included/excluded
 * from the list of files based on its name and type etc.  The value of
 * filter_level is set to either SERVER_FILTERS or ALL_FILTERS. */
static int is_excluded(char *fname, int is_dir, int filter_level)
{
#if 0 /* This currently never happens, so avoid a useless compare. */
        if (filter_level == NO_FILTERS)
                return 0;
#endif
        if (fname) {
                /* never exclude '.', even if somebody does --exclude '*' */
                if (fname[0] == '.' && !fname[1])
                        return 0;
                /* Handle the -R version of the '.' dir. */
                if (fname[0] == '/') {
                        int len = strlen(fname);
                        if (fname[len-1] == '.' && fname[len-2] == '/')
                                return 0;
                }
        }
        if (server_filter_list.head
            && check_filter(&server_filter_list, fname, is_dir) < 0)
                return 1;
        if (filter_level != ALL_FILTERS)
                return 0;
        if (filter_list.head
            && check_filter(&filter_list, fname, is_dir) < 0)
                return 1;
        return 0;
}

static void send_directory(int f, struct file_list *flist,
                           char *fbuf, int len, int flags);

static const char *pathname, *orig_dir;
static int pathname_len;


/* Make sure flist can hold at least flist->count + extra entries. */
static void flist_expand(struct file_list *flist, int extra)
{
        struct file_struct **new_ptr;

        if (flist->count + extra <= flist->malloced)
                return;

        if (flist->malloced < FLIST_START)
                flist->malloced = FLIST_START;
        else if (flist->malloced >= FLIST_LINEAR)
                flist->malloced += FLIST_LINEAR;
        else
                flist->malloced *= 2;

        /* In case count jumped or we are starting the list
         * with a known size just set it. */
        if (flist->malloced < flist->count + extra)
                flist->malloced = flist->count + extra;

        new_ptr = realloc_array(flist->files, struct file_struct *,
                                flist->malloced);

        if (verbose >= 2 && flist->malloced != FLIST_START) {
                rprintf(FCLIENT, "[%s] expand file_list to %.0f bytes, did%s move\n",
                    who_am_i(),
                    (double)sizeof flist->files[0] * flist->malloced,
                    (new_ptr == flist->files) ? " not" : "");
        }

        flist->files = new_ptr;

        if (!flist->files)
                out_of_memory("flist_expand");
}

static void flist_done_allocating(struct file_list *flist)
{
        void *ptr = pool_boundary(flist->file_pool, 8*1024);
        if (flist->pool_boundary == ptr)
                flist->pool_boundary = NULL; /* list didn't use any pool memory */
        else
                flist->pool_boundary = ptr;
}

int push_pathname(const char *dir, int len)
{
        if (dir == pathname)
                return 1;

        if (!orig_dir)
                orig_dir = strdup(curr_dir);

        if (pathname && !pop_dir(orig_dir)) {
                rsyserr(FERROR, errno, "pop_dir %s failed",
                        full_fname(orig_dir));
                exit_cleanup(RERR_FILESELECT);
        }

        if (dir && !push_dir(dir, 0)) {
                io_error |= IOERR_GENERAL;
                rsyserr(FERROR, errno, "push_dir %s failed in %s",
                        full_fname(dir), curr_dir);
                return 0;
        }

        pathname = dir;
        pathname_len = len >= 0 ? len : dir ? (int)strlen(dir) : 0;

        return 1;
}

static void send_file_entry(int f, struct file_struct *file, int ndx)
{
        static time_t modtime;
        static mode_t mode;
        static int64 dev;
        static dev_t rdev;
        static uint32 rdev_major;
        static uid_t uid;
        static gid_t gid;
        static char *user_name, *group_name;
        static char lastname[MAXPATHLEN];
        char fname[MAXPATHLEN];
        int first_hlink_ndx = -1;
        int l1, l2;
        int flags;

#ifdef ICONV_OPTION
        if (ic_send != (iconv_t)-1) {
                ICONV_CONST char *ibuf;
                char *obuf = fname;
                size_t ocnt = MAXPATHLEN, icnt;

                iconv(ic_send, NULL,0, NULL,0);
                if ((ibuf = (ICONV_CONST char *)file->dirname) != NULL) {
                    icnt = strlen(ibuf);
                    ocnt--; /* pre-subtract the space for the '/' */
                    if (iconv(ic_send, &ibuf,&icnt, &obuf,&ocnt) == (size_t)-1)
                        goto convert_error;
                    *obuf++ = '/';
                }

                ibuf = (ICONV_CONST char *)file->basename;
                icnt = strlen(ibuf);
                if (iconv(ic_send, &ibuf,&icnt, &obuf,&ocnt) == (size_t)-1) {
                  convert_error:
                        io_error |= IOERR_GENERAL;
                        rprintf(FINFO,
                            "[%s] cannot convert filename: %s (%s)\n",
                            who_am_i(), f_name(file, fname), strerror(errno));
                        return;
                }
                *obuf = '\0';
        } else
#endif
                f_name(file, fname);

        flags = file->flags & FLAG_TOP_DIR; /* FLAG_TOP_DIR == XMIT_TOP_DIR */

        if (file->mode == mode)
                flags |= XMIT_SAME_MODE;
        else
                mode = file->mode;
        if ((preserve_devices && IS_DEVICE(mode))
         || (preserve_specials && IS_SPECIAL(mode))) {
                if (protocol_version < 28) {
                        if (tmp_rdev == rdev)
                                flags |= XMIT_SAME_RDEV_pre28;
                        else
                                rdev = tmp_rdev;
                } else {
                        rdev = tmp_rdev;
                        if ((uint32)major(rdev) == rdev_major)
                                flags |= XMIT_SAME_RDEV_MAJOR;
                        else
                                rdev_major = major(rdev);
                        if (protocol_version < 30 && (uint32)minor(rdev) <= 0xFFu)
                                flags |= XMIT_RDEV_MINOR_8_pre30;
                }
        } else if (protocol_version < 28)
                rdev = MAKEDEV(0, 0);
        if (uid_ndx) {
                if ((uid_t)F_OWNER(file) == uid && *lastname)
                        flags |= XMIT_SAME_UID;
                else {
                        uid = F_OWNER(file);
                        if (uid_ndx && !numeric_ids) {
                                user_name = add_uid(uid);
                                if (inc_recurse && user_name)
                                        flags |= XMIT_USER_NAME_FOLLOWS;
                        }
                }
        }
        if (gid_ndx) {
                if ((gid_t)F_GROUP(file) == gid && *lastname)
                        flags |= XMIT_SAME_GID;
                else {
                        gid = F_GROUP(file);
                        if (gid_ndx && !numeric_ids) {
                                group_name = add_gid(gid);
                                if (inc_recurse && group_name)
                                        flags |= XMIT_GROUP_NAME_FOLLOWS;
                        }
                }
        }
        if (file->modtime == modtime)
                flags |= XMIT_SAME_TIME;
        else
                modtime = file->modtime;

#ifdef SUPPORT_HARD_LINKS
        if (tmp_dev != 0) {
                if (protocol_version >= 30) {
                        struct idev_node *np = idev_node(tmp_dev, tmp_ino);
                        first_hlink_ndx = (int32)(long)np->data - 1;
                        if (first_hlink_ndx < 0) {
                                np->data = (void*)(long)(ndx + 1);
                                flags |= XMIT_HLINK_FIRST;
                        }
                        flags |= XMIT_HLINKED;
                } else {
                        if (tmp_dev == dev) {
                                if (protocol_version >= 28)
                                        flags |= XMIT_SAME_DEV_pre30;
                        } else
                                dev = tmp_dev;
                        flags |= XMIT_HLINKED;
                }
        }
#endif

        for (l1 = 0;
            lastname[l1] && (fname[l1] == lastname[l1]) && (l1 < 255);
            l1++) {}
        l2 = strlen(fname+l1);

        if (l1 > 0)
                flags |= XMIT_SAME_NAME;
        if (l2 > 255)
                flags |= XMIT_LONG_NAME;

        /* We must make sure we don't send a zero flag byte or the
         * other end will terminate the flist transfer.  Note that
         * the use of XMIT_TOP_DIR on a non-dir has no meaning, so
         * it's harmless way to add a bit to the first flag byte. */
        if (protocol_version >= 28) {
                if (!flags && !S_ISDIR(mode))
                        flags |= XMIT_TOP_DIR;
                if ((flags & 0xFF00) || !flags) {
                        flags |= XMIT_EXTENDED_FLAGS;
                        write_shortint(f, flags);
                } else
                        write_byte(f, flags);
        } else {
                if (!(flags & 0xFF))
                        flags |= S_ISDIR(mode) ? XMIT_LONG_NAME : XMIT_TOP_DIR;
                write_byte(f, flags);
        }
        if (flags & XMIT_SAME_NAME)
                write_byte(f, l1);
        if (flags & XMIT_LONG_NAME)
                write_varint30(f, l2);
        else
                write_byte(f, l2);
        write_buf(f, fname + l1, l2);

        if (first_hlink_ndx >= 0) {
                write_varint30(f, first_hlink_ndx);
                goto the_end;
        }

        write_varlong30(f, F_LENGTH(file), 3);
        if (!(flags & XMIT_SAME_TIME)) {
                if (protocol_version >= 30)
                        write_varlong(f, modtime, 4);
                else
                        write_int(f, modtime);
        }
        if (!(flags & XMIT_SAME_MODE))
                write_int(f, to_wire_mode(mode));
        if (uid_ndx && !(flags & XMIT_SAME_UID)) {
                if (protocol_version < 30)
                        write_int(f, uid);
                else {
                        write_varint(f, uid);
                        if (flags & XMIT_USER_NAME_FOLLOWS) {
                                int len = strlen(user_name);
                                write_byte(f, len);
                                write_buf(f, user_name, len);
                        }
                }
        }
        if (gid_ndx && !(flags & XMIT_SAME_GID)) {
                if (protocol_version < 30)
                        write_int(f, gid);
                else {
                        write_varint(f, gid);
                        if (flags & XMIT_GROUP_NAME_FOLLOWS) {
                                int len = strlen(group_name);
                                write_byte(f, len);
                                write_buf(f, group_name, len);
                        }
                }
        }
        if ((preserve_devices && IS_DEVICE(mode))
         || (preserve_specials && IS_SPECIAL(mode))) {
                if (protocol_version < 28) {
                        if (!(flags & XMIT_SAME_RDEV_pre28))
                                write_int(f, (int)rdev);
                } else {
                        if (!(flags & XMIT_SAME_RDEV_MAJOR))
                                write_varint30(f, major(rdev));
                        if (protocol_version >= 30)
                                write_varint(f, minor(rdev));
                        else if (flags & XMIT_RDEV_MINOR_8_pre30)
                                write_byte(f, minor(rdev));
                        else
                                write_int(f, minor(rdev));
                }
        }

#ifdef SUPPORT_LINKS
        if (preserve_links && S_ISLNK(mode)) {
                const char *sl = F_SYMLINK(file);
                int len = strlen(sl);
                write_varint30(f, len);
                write_buf(f, sl, len);
        }
#endif

#ifdef SUPPORT_HARD_LINKS
        if (tmp_dev != 0 && protocol_version < 30) {
                if (protocol_version < 26) {
                        /* 32-bit dev_t and ino_t */
                        write_int(f, (int32)dev);
                        write_int(f, (int32)tmp_ino);
                } else {
                        /* 64-bit dev_t and ino_t */
                        if (!(flags & XMIT_SAME_DEV_pre30))
                                write_longint(f, dev);
                        write_longint(f, tmp_ino);
                }
        }
#endif

        if (always_checksum && (S_ISREG(mode) || protocol_version < 28)) {
                const char *sum;
                if (S_ISREG(mode))
                        sum = tmp_sum;
                else {
                        /* Prior to 28, we sent a useless set of nulls. */
                        sum = empty_sum;
                }
                write_buf(f, sum, checksum_len);
        }

  the_end:
        strlcpy(lastname, fname, MAXPATHLEN);

        if (S_ISREG(mode) || S_ISLNK(mode))
                stats.total_size += F_LENGTH(file);
}

static struct file_struct *recv_file_entry(struct file_list *flist,
                                           int xflags, int f)
{
        static int64 modtime;
        static mode_t mode;
        static int64 dev;
        static dev_t rdev;
        static uint32 rdev_major;
        static uid_t uid;
        static gid_t gid;
        static uint16 gid_flags;
        static char lastname[MAXPATHLEN], *lastdir;
        static int lastdir_depth, lastdir_len = -1;
        static unsigned int del_hier_name_len = 0;
        static int in_del_hier = 0;
        char thisname[MAXPATHLEN];
        unsigned int l1 = 0, l2 = 0;
        int alloc_len, basename_len, linkname_len;
        int extra_len = file_extra_cnt * EXTRA_LEN;
        int first_hlink_ndx = -1;
        OFF_T file_length;
        const char *basename;
        struct file_struct *file;
        alloc_pool_t *pool;
        char *bp;

        if (xflags & XMIT_SAME_NAME)
                l1 = read_byte(f);

        if (xflags & XMIT_LONG_NAME)
                l2 = read_varint30(f);
        else
                l2 = read_byte(f);

        if (l2 >= MAXPATHLEN - l1) {
                rprintf(FERROR,
                        "overflow: xflags=0x%x l1=%d l2=%d lastname=%s [%s]\n",
                        xflags, l1, l2, lastname, who_am_i());
                overflow_exit("recv_file_entry");
        }

        strlcpy(thisname, lastname, l1 + 1);
        read_sbuf(f, &thisname[l1], l2);
        thisname[l1 + l2] = 0;

        /* Abuse basename_len for a moment... */
        basename_len = strlcpy(lastname, thisname, MAXPATHLEN);

#ifdef ICONV_OPTION
        if (ic_recv != (iconv_t)-1) {
                char *obuf = thisname;
                ICONV_CONST char *ibuf = (ICONV_CONST char *)lastname;
                size_t ocnt = MAXPATHLEN, icnt = basename_len;

                if (icnt >= MAXPATHLEN) {
                        errno = E2BIG;
                        goto convert_error;
                }

                iconv(ic_recv, NULL,0, NULL,0);
                if (iconv(ic_recv, &ibuf,&icnt, &obuf,&ocnt) == (size_t)-1) {
                  convert_error:
                        io_error |= IOERR_GENERAL;
                        rprintf(FINFO,
                            "[%s] cannot convert filename: %s (%s)\n",
                            who_am_i(), lastname, strerror(errno));
                        obuf = thisname;
                }
                *obuf = '\0';
        }
#endif

        clean_fname(thisname, 0);

        if (sanitize_paths)
                sanitize_path(thisname, thisname, "", 0, NULL);

        if ((basename = strrchr(thisname, '/')) != NULL) {
                int len = basename++ - thisname;
                if (len != lastdir_len || memcmp(thisname, lastdir, len) != 0) {
                        lastdir = new_array(char, len + 1);
                        memcpy(lastdir, thisname, len);
                        lastdir[len] = '\0';
                        lastdir_len = len;
                        lastdir_depth = count_dir_elements(lastdir);
                }
        } else
                basename = thisname;
        basename_len = strlen(basename) + 1; /* count the '\0' */

#ifdef SUPPORT_HARD_LINKS
        if (protocol_version >= 30
         && BITS_SETnUNSET(xflags, XMIT_HLINKED, XMIT_HLINK_FIRST)) {
                struct file_struct *first;
                first_hlink_ndx = read_varint30(f);
                if (first_hlink_ndx < 0 || first_hlink_ndx >= flist->count) {
                        rprintf(FERROR,
                                "hard-link reference out of range: %d (%d)\n",
                                first_hlink_ndx, flist->count);
                        exit_cleanup(RERR_PROTOCOL);
                }
                first = flist->files[first_hlink_ndx];
                file_length = F_LENGTH(first);
                modtime = first->modtime;
                mode = first->mode;
                if (uid_ndx)
                        uid = F_OWNER(first);
                if (gid_ndx)
                        gid = F_GROUP(first);
                if ((preserve_devices && IS_DEVICE(mode))
                 || (preserve_specials && IS_SPECIAL(mode))) {
                        uint32 *devp = F_RDEV_P(first);
                        rdev = MAKEDEV(DEV_MAJOR(devp), DEV_MINOR(devp));
                        extra_len += 2 * EXTRA_LEN;
                }
                if (preserve_links && S_ISLNK(mode))
                        linkname_len = strlen(F_SYMLINK(first)) + 1;
                else
                        linkname_len = 0;
                goto create_object;
        }
#endif

        file_length = read_varlong30(f, 3);
        if (!(xflags & XMIT_SAME_TIME)) {
                if (protocol_version >= 30) {
                        modtime = read_varlong(f, 4);
#if SIZEOF_TIME_T < SIZEOF_INT64
                        if ((modtime > INT_MAX || modtime < INT_MIN) && !am_generator) {
                                rprintf(FERROR,
                                    "Time value of %s truncated on receiver.\n",
                                    lastname);
                        }
#endif
                } else
                        modtime = read_int(f);
        }
        if (!(xflags & XMIT_SAME_MODE))
                mode = from_wire_mode(read_int(f));

        if (chmod_modes && !S_ISLNK(mode))
                mode = tweak_mode(mode, chmod_modes);

        if (uid_ndx && !(xflags & XMIT_SAME_UID)) {
                if (protocol_version < 30)
                        uid = (uid_t)read_int(f);
                else {
                        uid = (uid_t)read_varint(f);
                        if (xflags & XMIT_USER_NAME_FOLLOWS)
                                uid = recv_user_name(f, uid);
                        else if (inc_recurse && am_root && !numeric_ids)
                                uid = match_uid(uid);
                }
        }
        if (gid_ndx && !(xflags & XMIT_SAME_GID)) {
                if (protocol_version < 30)
                        gid = (gid_t)read_int(f);
                else {
                        gid = (gid_t)read_varint(f);
                        gid_flags = 0;
                        if (xflags & XMIT_GROUP_NAME_FOLLOWS)
                                gid = recv_group_name(f, gid, &gid_flags);
                        else if (inc_recurse && (!am_root || !numeric_ids))
                                gid = match_gid(gid, &gid_flags);
                }
        }

        if ((preserve_devices && IS_DEVICE(mode))
         || (preserve_specials && IS_SPECIAL(mode))) {
                if (protocol_version < 28) {
                        if (!(xflags & XMIT_SAME_RDEV_pre28))
                                rdev = (dev_t)read_int(f);
                } else {
                        uint32 rdev_minor;
                        if (!(xflags & XMIT_SAME_RDEV_MAJOR))
                                rdev_major = read_varint30(f);
                        if (protocol_version >= 30)
                                rdev_minor = read_varint(f);
                        else if (xflags & XMIT_RDEV_MINOR_8_pre30)
                                rdev_minor = read_byte(f);
                        else
                                rdev_minor = read_int(f);
                        rdev = MAKEDEV(rdev_major, rdev_minor);
                }
                extra_len += 2 * EXTRA_LEN;
                file_length = 0;
        } else if (protocol_version < 28)
                rdev = MAKEDEV(0, 0);

#ifdef SUPPORT_LINKS
        if (preserve_links && S_ISLNK(mode)) {
                linkname_len = read_varint30(f) + 1; /* count the '\0' */
                if (linkname_len <= 0 || linkname_len > MAXPATHLEN) {
                        rprintf(FERROR, "overflow: linkname_len=%d\n",
                                linkname_len - 1);
                        overflow_exit("recv_file_entry");
                }
        }
        else
#endif
                linkname_len = 0;

#ifdef SUPPORT_HARD_LINKS
  create_object:
        if (preserve_hard_links) {
                if (protocol_version < 28 && S_ISREG(mode))
                        xflags |= XMIT_HLINKED;
                if (xflags & XMIT_HLINKED)
                        extra_len += EXTRA_LEN;
        }
#endif

#ifdef SUPPORT_ACLS
        /* We need one or two index int32s when we're preserving ACLs. */
        if (preserve_acls)
                extra_len += (S_ISDIR(mode) ? 2 : 1) * EXTRA_LEN;
#endif

        if (always_checksum && S_ISREG(mode))
                extra_len += SUM_EXTRA_CNT * EXTRA_LEN;

        if (file_length > 0xFFFFFFFFu && S_ISREG(mode))
                extra_len += EXTRA_LEN;

#if EXTRA_ROUNDING > 0
        if (extra_len & (EXTRA_ROUNDING * EXTRA_LEN))
                extra_len = (extra_len | (EXTRA_ROUNDING * EXTRA_LEN)) + EXTRA_LEN;
#endif

        if (inc_recurse && S_ISDIR(mode)) {
                if (one_file_system) {
                        /* Room to save the dir's device for -x */
                        extra_len += 2 * EXTRA_LEN;
                }
                pool = dir_flist->file_pool;
        } else
                pool = flist->file_pool;

        alloc_len = FILE_STRUCT_LEN + extra_len + basename_len
                  + linkname_len;
        bp = pool_alloc(pool, alloc_len, "recv_file_entry");

        memset(bp, 0, extra_len + FILE_STRUCT_LEN);
        bp += extra_len;
        file = (struct file_struct *)bp;
        bp += FILE_STRUCT_LEN;

        memcpy(bp, basename, basename_len);
        bp += basename_len + linkname_len; /* skip space for symlink too */

#ifdef SUPPORT_HARD_LINKS
        if (xflags & XMIT_HLINKED)
                file->flags |= FLAG_HLINKED;
#endif
        file->modtime = (time_t)modtime;
        file->len32 = (uint32)file_length;
        if (file_length > 0xFFFFFFFFu && S_ISREG(mode)) {
                file->flags |= FLAG_LENGTH64;
                OPT_EXTRA(file, 0)->unum = (uint32)(file_length >> 32);
        }
        file->mode = mode;
        if (uid_ndx)
                F_OWNER(file) = uid;
        if (gid_ndx) {
                F_GROUP(file) = gid;
                file->flags |= gid_flags;
        }
#ifdef ICONV_OPTION
        if (ic_ndx)
                F_NDX(file) = flist->count + flist->ndx_start;
#endif

        if (basename != thisname) {
                file->dirname = lastdir;
                F_DEPTH(file) = lastdir_depth + 1;
        } else
                F_DEPTH(file) = 1;

        if (S_ISDIR(mode)) {
                if (basename_len == 1+1 && *basename == '.') /* +1 for '\0' */
                        F_DEPTH(file)--;
                if (xflags & XMIT_TOP_DIR) {
                        in_del_hier = recurse;
                        del_hier_name_len = F_DEPTH(file) == 0 ? 0 : l1 + l2;
                        if (relative_paths && del_hier_name_len > 2
                            && lastname[del_hier_name_len-1] == '.'
                            && lastname[del_hier_name_len-2] == '/')
                                del_hier_name_len -= 2;
                        file->flags |= FLAG_TOP_DIR | FLAG_XFER_DIR;
                } else if (in_del_hier) {
                        if (!relative_paths || !del_hier_name_len
                         || (l1 >= del_hier_name_len
                          && lastname[del_hier_name_len] == '/'))
                                file->flags |= FLAG_XFER_DIR;
                        else
                                in_del_hier = 0;
                }
        }

        if ((preserve_devices && IS_DEVICE(mode))
         || (preserve_specials && IS_SPECIAL(mode))) {
                uint32 *devp = F_RDEV_P(file);
                DEV_MAJOR(devp) = major(rdev);
                DEV_MINOR(devp) = minor(rdev);
        }

#ifdef SUPPORT_LINKS
        if (linkname_len) {
                bp = (char*)file->basename + basename_len;
                if (first_hlink_ndx >= 0) {
                        struct file_struct *first = flist->files[first_hlink_ndx];
                        memcpy(bp, F_SYMLINK(first), linkname_len);
                } else
                        read_sbuf(f, bp, linkname_len - 1);
                if (sanitize_paths)
                        sanitize_path(bp, bp, "", lastdir_depth, NULL);
        }
#endif

#ifdef SUPPORT_HARD_LINKS
        if (preserve_hard_links && xflags & XMIT_HLINKED) {
                if (protocol_version >= 30) {
                        F_HL_GNUM(file) = xflags & XMIT_HLINK_FIRST
                                        ? flist->count : first_hlink_ndx;
                } else {
                        static int32 cnt = 0;
                        struct idev_node *np;
                        int64 ino;
                        int32 ndx;
                        if (protocol_version < 26) {
                                dev = read_int(f);
                                ino = read_int(f);
                        } else {
                                if (!(xflags & XMIT_SAME_DEV_pre30))
                                        dev = read_longint(f);
                                ino = read_longint(f);
                        }
                        np = idev_node(dev, ino);
                        ndx = (int32)(long)np->data - 1;
                        if (ndx < 0) {
                                ndx = cnt++;
                                np->data = (void*)(long)cnt;
                        }
                        F_HL_GNUM(file) = ndx;
                }
        }
#endif

        if (always_checksum && (S_ISREG(mode) || protocol_version < 28)) {
                if (S_ISREG(mode))
                        bp = (char*)F_SUM(file);
                else {
                        /* Prior to 28, we get a useless set of nulls. */
                        bp = tmp_sum;
                }
                if (first_hlink_ndx >= 0) {
                        struct file_struct *first = flist->files[first_hlink_ndx];
                        memcpy(bp, F_SUM(first), checksum_len);
                } else
                        read_buf(f, bp, checksum_len);
        }

#ifdef SUPPORT_ACLS
        if (preserve_acls && !S_ISLNK(mode))
                receive_acl(file, f);
#endif
#ifdef SUPPORT_XATTRS
        if (preserve_xattrs)
                receive_xattr(file, f );
#endif

        if (S_ISREG(mode) || S_ISLNK(mode))
                stats.total_size += file_length;

        return file;
}

/**
 * Create a file_struct for a named file by reading its stat()
 * information and performing extensive checks against global
 * options.
 *
 * @return the new file, or NULL if there was an error or this file
 * should be excluded.
 *
 * @todo There is a small optimization opportunity here to avoid
 * stat()ing the file in some circumstances, which has a certain cost.
 * We are called immediately after doing readdir(), and so we may
 * already know the d_type of the file.  We could for example avoid
 * statting directories if we're not recursing, but this is not a very
 * important case.  Some systems may not have d_type.
 **/
struct file_struct *make_file(const char *fname, struct file_list *flist,
                              STRUCT_STAT *stp, int flags, int filter_level)
{
        static char *lastdir;
        static int lastdir_len = -1;
        struct file_struct *file;
        STRUCT_STAT st;
        char thisname[MAXPATHLEN];
        char linkname[MAXPATHLEN];
        int alloc_len, basename_len, linkname_len;
        int extra_len = file_extra_cnt * EXTRA_LEN;
        const char *basename;
        alloc_pool_t *pool;
        char *bp;

        if (strlcpy(thisname, fname, sizeof thisname)
            >= sizeof thisname - pathname_len) {
                rprintf(FINFO, "skipping overly long name: %s\n", fname);
                return NULL;
        }
        clean_fname(thisname, 0);
        if (sanitize_paths)
                sanitize_path(thisname, thisname, "", 0, NULL);

        if (stp && S_ISDIR(stp->st_mode)) {
                st = *stp; /* Needed for "symlink/." with --relative. */
                *linkname = '\0'; /* make IBM code checker happy */
        } else if (readlink_stat(thisname, &st, linkname) != 0) {
                int save_errno = errno;
                /* See if file is excluded before reporting an error. */
                if (filter_level != NO_FILTERS
                 && (is_excluded(thisname, 0, filter_level)
                  || is_excluded(thisname, 1, filter_level))) {
                        if (ignore_perishable && save_errno != ENOENT)
                                non_perishable_cnt++;
                        return NULL;
                }
                if (save_errno == ENOENT) {
#ifdef SUPPORT_LINKS
                        /* Avoid "vanished" error if symlink points nowhere. */
                        if (copy_links && x_lstat(thisname, &st, NULL) == 0
                            && S_ISLNK(st.st_mode)) {
                                io_error |= IOERR_GENERAL;
                                rprintf(FERROR, "symlink has no referent: %s\n",
                                        full_fname(thisname));
                        } else
#endif
                        {
                                enum logcode c = am_daemon && protocol_version < 28
                                    ? FERROR : FINFO;
                                io_error |= IOERR_VANISHED;
                                rprintf(c, "file has vanished: %s\n",
                                        full_fname(thisname));
                        }
                } else {
                        io_error |= IOERR_GENERAL;
                        rsyserr(FERROR, save_errno, "readlink %s failed",
                                full_fname(thisname));
                }
                return NULL;
        }

        /* backup.c calls us with filter_level set to NO_FILTERS. */
        if (filter_level == NO_FILTERS)
                goto skip_filters;

        if (S_ISDIR(st.st_mode) && !xfer_dirs) {
                rprintf(FINFO, "skipping directory %s\n", thisname);
                return NULL;
        }

        /* -x only affects directories because we need to avoid recursing
         * into a mount-point directory, not to avoid copying a symlinked
         * file if -L (or similar) was specified. */
        if (one_file_system && st.st_dev != filesystem_dev
         && S_ISDIR(st.st_mode)) {
                if (one_file_system > 1) {
                        if (verbose > 2) {
                                rprintf(FINFO, "skipping mount-point dir %s\n",
                                        thisname);
                        }
                        return NULL;
                }
                flags |= FLAG_MOUNT_DIR;
        }

        if (is_excluded(thisname, S_ISDIR(st.st_mode) != 0, filter_level)) {
                if (ignore_perishable)
                        non_perishable_cnt++;
                return NULL;
        }

        if (lp_ignore_nonreadable(module_id)) {
#ifdef SUPPORT_LINKS
                if (!S_ISLNK(st.st_mode))
#endif
                        if (access(thisname, R_OK) != 0)
                                return NULL;
        }

  skip_filters:

        /* Only divert a directory in the main transfer. */
        if (flist) {
                if (flist->prev && S_ISDIR(st.st_mode)
                 && flags & FLAG_DIVERT_DIRS) {
                        /* Room for parent/sibling/next-child info. */
                        extra_len += 3 * EXTRA_LEN;
                        dir_count++;
                        pool = dir_flist->file_pool;
                } else
                        pool = flist->file_pool;
        } else
                pool = NULL;

        if (verbose > 2) {
                rprintf(FINFO, "[%s] make_file(%s,*,%d)\n",
                        who_am_i(), thisname, filter_level);
        }

        if ((basename = strrchr(thisname, '/')) != NULL) {
                int len = basename++ - thisname;
                if (len != lastdir_len || memcmp(thisname, lastdir, len) != 0) {
                        lastdir = new_array(char, len + 1);
                        memcpy(lastdir, thisname, len);
                        lastdir[len] = '\0';
                        lastdir_len = len;
                }
        } else
                basename = thisname;
        basename_len = strlen(basename) + 1; /* count the '\0' */

#ifdef SUPPORT_LINKS
        linkname_len = S_ISLNK(st.st_mode) ? strlen(linkname) + 1 : 0;
#else
        linkname_len = 0;
#endif

        if (st.st_size > 0xFFFFFFFFu && S_ISREG(st.st_mode))
                extra_len += EXTRA_LEN;

#if EXTRA_ROUNDING > 0
        if (extra_len & (EXTRA_ROUNDING * EXTRA_LEN))
                extra_len = (extra_len | (EXTRA_ROUNDING * EXTRA_LEN)) + EXTRA_LEN;
#endif

        alloc_len = FILE_STRUCT_LEN + extra_len + basename_len
                  + linkname_len;
        if (pool)
                bp = pool_alloc(pool, alloc_len, "make_file");
        else {
                if (!(bp = new_array(char, alloc_len)))
                        out_of_memory("make_file");
        }

        memset(bp, 0, extra_len + FILE_STRUCT_LEN);
        bp += extra_len;
        file = (struct file_struct *)bp;
        bp += FILE_STRUCT_LEN;

        memcpy(bp, basename, basename_len);
        bp += basename_len + linkname_len; /* skip space for symlink too */

#ifdef SUPPORT_HARD_LINKS
        if (preserve_hard_links && flist && flist->prev) {
                if (protocol_version >= 28
                 ? (!S_ISDIR(st.st_mode) && st.st_nlink > 1)
                 : S_ISREG(st.st_mode)) {
                        tmp_dev = st.st_dev;
                        tmp_ino = st.st_ino;
                } else
                        tmp_dev = 0;
        }
#endif

#ifdef HAVE_STRUCT_STAT_ST_RDEV
        if (IS_DEVICE(st.st_mode) || IS_SPECIAL(st.st_mode)) {
                tmp_rdev = st.st_rdev;
                st.st_size = 0;
        }
#endif

        file->flags = flags;
        file->modtime = st.st_mtime;
        file->len32 = (uint32)st.st_size;
        if (st.st_size > 0xFFFFFFFFu && S_ISREG(st.st_mode)) {
                file->flags |= FLAG_LENGTH64;
                OPT_EXTRA(file, 0)->unum = (uint32)(st.st_size >> 32);
        }
        file->mode = st.st_mode;
        if (uid_ndx)
                F_OWNER(file) = st.st_uid;
        if (gid_ndx)
                F_GROUP(file) = st.st_gid;

        if (basename != thisname)
                file->dirname = lastdir;

#ifdef SUPPORT_LINKS
        if (linkname_len) {
                bp = (char*)file->basename + basename_len;
                memcpy(bp, linkname, linkname_len);
        }
#endif

        if (always_checksum && am_sender && S_ISREG(st.st_mode))
                file_checksum(thisname, tmp_sum, st.st_size);

        F_PATHNAME(file) = pathname;

        /* This code is only used by the receiver when it is building
         * a list of files for a delete pass. */
        if (keep_dirlinks && linkname_len && flist) {
                STRUCT_STAT st2;
                int save_mode = file->mode;
                file->mode = S_IFDIR; /* Find a directory with our name. */
                if (flist_find(dir_flist, file) >= 0
                 && x_stat(thisname, &st2, NULL) == 0 && S_ISDIR(st2.st_mode)) {
                        file->modtime = st2.st_mtime;
                        file->len32 = 0;
                        file->mode = st2.st_mode;
                        if (uid_ndx)
                                F_OWNER(file) = st2.st_uid;
                        if (gid_ndx)
                                F_GROUP(file) = st2.st_gid;
                } else
                        file->mode = save_mode;
        }

        if (basename_len == 0+1)
                return NULL;

#ifdef ICONV_OPTION
        if (ic_ndx)
                F_NDX(file) = dir_count - 1;
#endif

        return file;
}

/* Only called for temporary file_struct entries created by make_file(). */
void unmake_file(struct file_struct *file)
{
        int extra_cnt = file_extra_cnt + LEN64_BUMP(file);
#if EXTRA_ROUNDING > 0
        if (extra_cnt & EXTRA_ROUNDING)
                extra_cnt = (extra_cnt | EXTRA_ROUNDING) + 1;
#endif
        free(REQ_EXTRA(file, extra_cnt));
}

static struct file_struct *send_file_name(int f, struct file_list *flist,
                                          char *fname, STRUCT_STAT *stp,
                                          int flags, int filter_flags)
{
        struct file_struct *file;
#if defined SUPPORT_ACLS || defined SUPPORT_XATTRS
        statx sx;
#endif

        file = make_file(fname, flist, stp, flags, filter_flags);
        if (!file)
                return NULL;

        if (chmod_modes && !S_ISLNK(file->mode))
                file->mode = tweak_mode(file->mode, chmod_modes);

#ifdef SUPPORT_ACLS
        if (preserve_acls && !S_ISLNK(file->mode) && f >= 0) {
                sx.st.st_mode = file->mode;
                sx.acc_acl = sx.def_acl = NULL;
                if (get_acl(fname, &sx) < 0)
                        return NULL;
        }
#endif
#ifdef SUPPORT_XATTRS
        if (preserve_xattrs && f >= 0) {
                sx.xattr = NULL;
                if (get_xattr(fname, &sx) < 0)
                        return NULL;
        }
#endif

        maybe_emit_filelist_progress(flist->count + flist_count_offset);

        flist_expand(flist, 1);
        flist->files[flist->count++] = file;
        if (f >= 0) {
                send_file_entry(f, file, flist->count - 1);
#ifdef SUPPORT_ACLS
                if (preserve_acls && !S_ISLNK(file->mode)) {
                        send_acl(&sx, f);
                        free_acl(&sx);
                }
#endif
#ifdef SUPPORT_XATTRS
                if (preserve_xattrs) {
                        F_XATTR(file) = send_xattr(&sx, f);
                        free_xattr(&sx);
                }
#endif
        }
        return file;
}

static void send_if_directory(int f, struct file_list *flist,
                              struct file_struct *file,
                              char *fbuf, unsigned int ol,
                              int flags)
{
        char is_dot_dir = fbuf[ol-1] == '.' && (ol == 1 || fbuf[ol-2] == '/');

        if (S_ISDIR(file->mode)
            && !(file->flags & FLAG_MOUNT_DIR) && f_name(file, fbuf)) {
                void *save_filters;
                unsigned int len = strlen(fbuf);
                if (len > 1 && fbuf[len-1] == '/')
                        fbuf[--len] = '\0';
                if (len >= MAXPATHLEN - 1) {
                        io_error |= IOERR_GENERAL;
                        rprintf(FERROR, "skipping long-named directory: %s\n",
                                full_fname(fbuf));
                        return;
                }
                save_filters = push_local_filters(fbuf, len);
                send_directory(f, flist, fbuf, len, flags);
                pop_local_filters(save_filters);
                fbuf[ol] = '\0';
                if (is_dot_dir)
                        fbuf[ol-1] = '.';
        }
}

static int file_compare(const void *file1, const void *file2)
{
        return f_name_cmp(*(struct file_struct **)file1,
                          *(struct file_struct **)file2);
}

/* The guts of a merge-sort algorithm.  This was derived from the glibc
 * version, but I (Wayne) changed the merge code to do less copying and
 * to require only half the amount of temporary memory. */
static void fsort_tmp(struct file_struct **fp, size_t num,
                      struct file_struct **tmp)
{
        struct file_struct **f1, **f2, **t;
        size_t n1, n2;

        n1 = num / 2;
        n2 = num - n1;
        f1 = fp;
        f2 = fp + n1;

        if (n1 > 1)
                fsort_tmp(f1, n1, tmp);
        if (n2 > 1)
                fsort_tmp(f2, n2, tmp);

        while (f_name_cmp(*f1, *f2) <= 0) {
                if (!--n1)
                        return;
                f1++;
        }

        t = tmp;
        memcpy(t, f1, n1 * PTR_SIZE);

        *f1++ = *f2++, n2--;

        while (n1 > 0 && n2 > 0) {
                if (f_name_cmp(*t, *f2) <= 0)
                        *f1++ = *t++, n1--;
                else
                        *f1++ = *f2++, n2--;
        }

        if (n1 > 0)
                memcpy(f1, t, n1 * PTR_SIZE);
}

/* This file-struct sorting routine makes sure that any identical names in
 * the file list stay in the same order as they were in the original list.
 * This is particularly vital in inc_recurse mode where we expect a sort
 * on the flist to match the exact order of a sort on the dir_flist. */
static void fsort(struct file_struct **fp, size_t num)
{
        if (num <= 1)
                return;

        if (use_qsort)
                qsort(fp, num, PTR_SIZE, file_compare);
        else {
                struct file_struct **tmp = new_array(struct file_struct *,
                                                     (num+1) / 2);
                fsort_tmp(fp, num, tmp);
                free(tmp);
        }
}

/* We take an entire set of sibling dirs from the sorted flist and link them
 * into the tree, setting the appropriate parent/child/sibling pointers. */
static void add_dirs_to_tree(int parent_ndx, struct file_list *from_flist,
                             int dir_cnt)
{
        int i;
        int32 *dp = NULL;
        int32 *parent_dp = parent_ndx < 0 ? NULL
                         : F_DIRNODE_P(dir_flist->sorted[parent_ndx]);

        flist_expand(dir_flist, dir_cnt);
        dir_flist->sorted = dir_flist->files;

        for (i = 0; dir_cnt; i++) {
                struct file_struct *file = from_flist->sorted[i];

                if (!S_ISDIR(file->mode))
                        continue;

                dir_flist->files[dir_flist->count++] = file;
                dir_cnt--;

                if (!(file->flags & FLAG_XFER_DIR)
                 || file->flags & FLAG_MOUNT_DIR)
                        continue;

                if (dp)
                        DIR_NEXT_SIBLING(dp) = dir_flist->count - 1;
                else if (parent_dp)
                        DIR_FIRST_CHILD(parent_dp) = dir_flist->count - 1;
                else
                        send_dir_ndx = dir_flist->count - 1;

                dp = F_DIRNODE_P(file);
                DIR_PARENT(dp) = parent_ndx;
                DIR_FIRST_CHILD(dp) = -1;
        }
        if (dp)
                DIR_NEXT_SIBLING(dp) = -1;
}

/* This function is normally called by the sender, but the receiving side also
 * calls it from get_dirlist() with f set to -1 so that we just construct the
 * file list in memory without sending it over the wire.  Also, get_dirlist()
 * might call this with f set to -2, which also indicates that local filter
 * rules should be ignored. */
static void send_directory(int f, struct file_list *flist, char *fbuf, int len,
                           int flags)
{
        struct dirent *di;
        unsigned remainder;
        char *p;
        DIR *d;
        int divert_dirs = (flags & FLAG_DIVERT_DIRS) != 0;
        int start = flist->count;
        int filter_flags = f == -2 ? SERVER_FILTERS : ALL_FILTERS;

        assert(flist != NULL);

        if (!(d = opendir(fbuf))) {
                io_error |= IOERR_GENERAL;
                rsyserr(FERROR, errno, "opendir %s failed", full_fname(fbuf));
                return;
        }

        p = fbuf + len;
        if (len != 1 || *fbuf != '/')
                *p++ = '/';
        *p = '\0';
        remainder = MAXPATHLEN - (p - fbuf);

        for (errno = 0, di = readdir(d); di; errno = 0, di = readdir(d)) {
                char *dname = d_name(di);
                if (dname[0] == '.' && (dname[1] == '\0'
                    || (dname[1] == '.' && dname[2] == '\0')))
                        continue;
                if (strlcpy(p, dname, remainder) >= remainder) {
                        io_error |= IOERR_GENERAL;
                        rprintf(FINFO,
                                "cannot send long-named file %s\n",
                                full_fname(fbuf));
                        continue;
                }

                send_file_name(f, flist, fbuf, NULL, flags, filter_flags);
        }

        fbuf[len] = '\0';

        if (errno) {
                io_error |= IOERR_GENERAL;
                rsyserr(FERROR, errno, "readdir(%s)", full_fname(fbuf));
        }

        closedir(d);

        if (f >= 0 && recurse && !divert_dirs) {
                int i, end = flist->count - 1;
                /* send_if_directory() bumps flist->count, so use "end". */
                for (i = start; i <= end; i++)
                        send_if_directory(f, flist, flist->files[i], fbuf, len, flags);
        }
}

static void send1extra(int f, struct file_struct *file, struct file_list *flist)
{
        char fbuf[MAXPATHLEN];
        int dlen;

        f_name(file, fbuf);
        dlen = strlen(fbuf);

        if (F_PATHNAME(file) != pathname) {
                if (!push_pathname(F_PATHNAME(file), -1))
                        exit_cleanup(RERR_FILESELECT);
        }

        change_local_filter_dir(fbuf, dlen, send_dir_depth);

        send_directory(f, flist, fbuf, dlen, FLAG_DIVERT_DIRS | FLAG_XFER_DIR);
}

void send_extra_file_list(int f, int at_least)
{
        struct file_list *flist;
        int64 start_write;
        int future_cnt, save_io_error = io_error;

        if (flist_eof)
                return;

        /* Keep sending data until we have the requested number of
         * files in the upcoming file-lists. */
        if (cur_flist->next) {
                flist = first_flist->prev; /* the newest flist */
                future_cnt = flist->count + flist->ndx_start
                           - cur_flist->next->ndx_start;
        } else
                future_cnt = 0;
        while (future_cnt < at_least) {
                struct file_struct *file = dir_flist->sorted[send_dir_ndx];
                int dir_ndx, dstart = dir_count;
                int32 *dp;

                flist = flist_new(0, "send_extra_file_list");
                start_write = stats.total_written;

#ifdef ICONV_OPTION
                if (ic_ndx)
                        dir_ndx = F_NDX(file);
                else
#endif
                        dir_ndx = send_dir_ndx;
                write_ndx(f, NDX_FLIST_OFFSET - dir_ndx);

                send1extra(f, file, flist);
                dp = F_DIRNODE_P(file);

                /* If there are any duplicate directory names that follow, we
                 * send all the dirs together in one file-list.  The dir_flist
                 * tree links all the child subdirs onto the last dup dir. */
                while ((dir_ndx = DIR_NEXT_SIBLING(dp)) >= 0
                    && dir_flist->sorted[dir_ndx]->flags & FLAG_DUPLICATE) {
                        send_dir_ndx = dir_ndx;
                        file = dir_flist->sorted[dir_ndx];
                        send1extra(f, file, flist);
                        dp = F_DIRNODE_P(file);
                }

                write_byte(f, 0);

#ifdef ICONV_OPTION
                if (need_unsorted_flist) {
                        if (!(flist->sorted = new_array(struct file_struct *, flist->count)))
                                out_of_memory("send_extra_file_list");
                        memcpy(flist->sorted, flist->files,
                               flist->count * sizeof (struct file_struct*));
                } else
#endif
                        flist->sorted = flist->files;

                clean_flist(flist, 0);

                add_dirs_to_tree(send_dir_ndx, flist, dir_count - dstart);
                flist_done_allocating(flist);

                file_total += flist->count;
                future_cnt += flist->count;
                stats.flist_size += stats.total_written - start_write;
                stats.num_files += flist->count;
                if (verbose > 3)
                        output_flist(flist);

                if (DIR_FIRST_CHILD(dp) >= 0) {
                        send_dir_ndx = DIR_FIRST_CHILD(dp);
                        send_dir_depth++;
                } else {
                        while (DIR_NEXT_SIBLING(dp) < 0) {
                                if ((send_dir_ndx = DIR_PARENT(dp)) < 0) {
                                        write_ndx(f, NDX_FLIST_EOF);
                                        flist_eof = 1;
                                        change_local_filter_dir(NULL, 0, 0);
                                        goto finish;
                                }
                                send_dir_depth--;
                                file = dir_flist->sorted[send_dir_ndx];
                                dp = F_DIRNODE_P(file);
                        }
                        send_dir_ndx = DIR_NEXT_SIBLING(dp);
                }
        }

  finish:
        if (io_error != save_io_error && !ignore_errors)
                send_msg_int(MSG_IO_ERROR, io_error);
}

struct file_list *send_file_list(int f, int argc, char *argv[])
{
        static const char *lastdir;
        static int lastdir_len = -1;
        int len, dirlen;
        STRUCT_STAT st;
        char *p, *dir;
        char lastpath[MAXPATHLEN] = "";
        struct file_list *flist;
        struct timeval start_tv, end_tv;
        int64 start_write;
        int use_ff_fd = 0;
        int flags, disable_buffering;

        rprintf(FLOG, "building file list\n");
        if (show_filelist_p())
                start_filelist_progress("building file list");
        else if (inc_recurse && verbose && !am_server)
                rprintf(FCLIENT, "sending incremental file list\n");

        start_write = stats.total_written;
        gettimeofday(&start_tv, NULL);

#ifdef SUPPORT_HARD_LINKS
        if (preserve_hard_links && protocol_version >= 30 && !cur_flist)
                init_hard_links();
#endif

        flist = cur_flist = flist_new(0, "send_file_list");
        if (inc_recurse) {
                dir_flist = flist_new(FLIST_TEMP, "send_file_list");
                flags = FLAG_DIVERT_DIRS;
        } else {
                dir_flist = cur_flist;
                flags = 0;
        }

        disable_buffering = io_start_buffering_out(f);
        if (filesfrom_fd >= 0) {
                if (argv[0] && !push_dir(argv[0], 0)) {
                        rsyserr(FERROR, errno, "push_dir %s failed in %s",
                                full_fname(argv[0]), curr_dir);
                        exit_cleanup(RERR_FILESELECT);
                }
                use_ff_fd = 1;
        }

        while (1) {
                char fbuf[MAXPATHLEN];
                char *fn;
                int is_dot_dir;

                if (use_ff_fd) {
                        if (read_filesfrom_line(filesfrom_fd, fbuf) == 0)
                                break;
                        sanitize_path(fbuf, fbuf, "", 0, NULL);
                } else {
                        if (argc-- == 0)
                                break;
                        strlcpy(fbuf, *argv++, MAXPATHLEN);
                        if (sanitize_paths)
                                sanitize_path(fbuf, fbuf, "", 0, NULL);
                }

                len = strlen(fbuf);
                if (relative_paths) {
                        /* We clean up fbuf below. */
                        is_dot_dir = 0;
                } else if (!len || fbuf[len - 1] == '/') {
                        if (len == 2 && fbuf[0] == '.') {
                                /* Turn "./" into just "." rather than "./." */
                                fbuf[1] = '\0';
                        } else {
                                if (len + 1 >= MAXPATHLEN)
                                        overflow_exit("send_file_list");
                                fbuf[len++] = '.';
                                fbuf[len] = '\0';
                        }
                        is_dot_dir = 1;
                } else if (len > 1 && fbuf[len-1] == '.' && fbuf[len-2] == '.'
                    && (len == 2 || fbuf[len-3] == '/')) {
                        if (len + 2 >= MAXPATHLEN)
                                overflow_exit("send_file_list");
                        fbuf[len++] = '/';
                        fbuf[len++] = '.';
                        fbuf[len] = '\0';
                        is_dot_dir = 1;
                } else {
                        is_dot_dir = fbuf[len-1] == '.'
                                   && (len == 1 || fbuf[len-2] == '/');
                }

                dir = NULL;

                if (!relative_paths) {
                        p = strrchr(fbuf, '/');
                        if (p) {
                                *p = '\0';
                                if (p == fbuf)
                                        dir = "/";
                                else
                                        dir = fbuf;
                                len -= p - fbuf + 1;
                                fn = p + 1;
                        } else
                                fn = fbuf;
                } else {
                        if ((p = strstr(fbuf, "/./")) != NULL) {
                                *p = '\0';
                                if (p == fbuf)
                                        dir = "/";
                                else
                                        dir = fbuf;
                                len -= p - fbuf + 3;
                                fn = p + 3;
                        } else
                                fn = fbuf;
                        /* Get rid of trailing "/" and "/.". */
                        while (len) {
                                if (fn[len - 1] == '/') {
                                        is_dot_dir = 1;
                                        if (!--len && !dir) {
                                                len++;
                                                break;
                                        }
                                }
                                else if (len >= 2 && fn[len - 1] == '.'
                                                  && fn[len - 2] == '/') {
                                        is_dot_dir = 1;
                                        if (!(len -= 2) && !dir) {
                                                len++;
                                                break;
                                        }
                                } else
                                        break;
                        }
                        if (len == 1 && fn[0] == '/')
                                fn[len++] = '.';
                        fn[len] = '\0';
                        /* Reject a ".." dir in the active part of the path. */
                        for (p = fn; (p = strstr(p, "..")) != NULL; p += 2) {
                                if ((p[2] == '/' || p[2] == '\0')
                                 && (p == fn || p[-1] == '/')) {
                                        rprintf(FERROR,
                                            "found \"..\" dir in relative path: %s\n",
                                            fbuf);
                                        exit_cleanup(RERR_SYNTAX);
                                }
                        }
                }

                if (!*fn) {
                        len = 1;
                        fn = ".";
                }

                dirlen = dir ? strlen(dir) : 0;
                if (dirlen != lastdir_len || memcmp(lastdir, dir, dirlen) != 0) {
                        if (!push_pathname(dir ? strdup(dir) : NULL, dirlen))
                                goto push_error;
                        lastdir = pathname;
                        lastdir_len = pathname_len;
                } else if (!push_pathname(lastdir, lastdir_len)) {
                  push_error:
                        io_error |= IOERR_GENERAL;
                        rsyserr(FERROR, errno, "push_dir %s failed in %s",
                                full_fname(dir), curr_dir);
                        continue;
                }

                if (fn != fbuf)
                        memmove(fbuf, fn, len + 1);

                if (link_stat(fbuf, &st, copy_dirlinks) != 0) {
                        io_error |= IOERR_GENERAL;
                        rsyserr(FERROR, errno, "link_stat %s failed",
                                full_fname(fbuf));
                        continue;
                }

                if (S_ISDIR(st.st_mode) && !xfer_dirs) {
                        rprintf(FINFO, "skipping directory %s\n", fbuf);
                        continue;
                }

                if (implied_dirs && (p=strrchr(fbuf,'/')) && p != fbuf) {
                        /* Send the implied directories at the start of the
                         * source spec, so we get their permissions right. */
                        char *lp = lastpath, *slash = fbuf;
                        *p = '\0';
                        /* Skip any initial directories in our path that we
                         * have in common with lastpath. */
                        for (fn = fbuf; *fn && *lp == *fn; lp++, fn++) {
                                if (*fn == '/')
                                        slash = fn;
                        }
                        *p = '/';
                        if (fn != p || (*lp && *lp != '/')) {
                                int save_copy_links = copy_links;
                                int save_xfer_dirs = xfer_dirs;
                                int dir_flags = inc_recurse ? FLAG_DIVERT_DIRS : 0;
                                copy_links |= copy_unsafe_links;
                                xfer_dirs = 1;
                                while ((slash = strchr(slash+1, '/')) != 0) {
                                        *slash = '\0';
                                        send_file_name(f, flist, fbuf, NULL,
                                                       dir_flags, ALL_FILTERS);
                                        *slash = '/';
                                }
                                copy_links = save_copy_links;
                                xfer_dirs = save_xfer_dirs;
                                *p = '\0';
                                strlcpy(lastpath, fbuf, sizeof lastpath);
                                *p = '/';
                        }
                }

                if (one_file_system)
                        filesystem_dev = st.st_dev;

                if (recurse || (xfer_dirs && is_dot_dir)) {
                        struct file_struct *file;
                        int top_flags = FLAG_TOP_DIR | FLAG_XFER_DIR | flags;
                        file = send_file_name(f, flist, fbuf, &st,
                                              top_flags, ALL_FILTERS);
                        if (file && !inc_recurse)
                                send_if_directory(f, flist, file, fbuf, len, flags);
                } else
                        send_file_name(f, flist, fbuf, &st, flags, ALL_FILTERS);
        }

        gettimeofday(&end_tv, NULL);
        stats.flist_buildtime = (int64)(end_tv.tv_sec - start_tv.tv_sec) * 1000
                              + (end_tv.tv_usec - start_tv.tv_usec) / 1000;
        if (stats.flist_buildtime == 0)
                stats.flist_buildtime = 1;
        start_tv = end_tv;

        write_byte(f, 0); /* Indicate end of file list */

#ifdef SUPPORT_HARD_LINKS
        if (preserve_hard_links && protocol_version >= 30 && !inc_recurse)
                idev_destroy();
#endif

        if (show_filelist_p())
                finish_filelist_progress(flist);

        gettimeofday(&end_tv, NULL);
        stats.flist_xfertime = (int64)(end_tv.tv_sec - start_tv.tv_sec) * 1000
                             + (end_tv.tv_usec - start_tv.tv_usec) / 1000;

        /* When converting names, both sides keep an unsorted file-list array
         * because the names will differ on the sending and receiving sides
         * (both sides will use the unsorted index number for each item). */

        /* Sort the list without removing any duplicates.  This allows the
         * receiving side to ask for whatever name it kept.  For incremental
         * recursion mode, the sender marks duplicate dirs so that it can
         * send them together in a single file-list. */
#ifdef ICONV_OPTION
        if (need_unsorted_flist) {
                if (inc_recurse) {
                        if (!(flist->sorted = new_array(struct file_struct *, flist->count)))
                                out_of_memory("send_file_list");
                        memcpy(flist->sorted, flist->files,
                               flist->count * sizeof (struct file_struct*));
                        clean_flist(flist, 0);
                } else
                        flist->sorted = flist->files;
        } else
#endif
        {
                flist->sorted = flist->files;
                clean_flist(flist, 0);
        }
        file_total += flist->count;

        if (!numeric_ids && !inc_recurse)
                send_id_list(f);

        /* send the io_error flag */
        if (protocol_version < 30)
                write_int(f, ignore_errors ? 0 : io_error);
        else if (io_error && !ignore_errors)
                send_msg_int(MSG_IO_ERROR, io_error);

        if (disable_buffering)
                io_end_buffering_out();

        stats.flist_size = stats.total_written - start_write;
        stats.num_files = flist->count;

        if (verbose > 3)
                output_flist(flist);

        if (verbose > 2)
                rprintf(FINFO, "send_file_list done\n");

        if (inc_recurse) {
                add_dirs_to_tree(-1, flist, dir_count);
                flist_done_allocating(flist);
                if (send_dir_ndx < 0) {
                        write_ndx(f, NDX_FLIST_EOF);
                        flist_eof = 1;
                }
                else if (file_total == 1) {
                        /* If we're creating incremental file-lists and there
                         * was just 1 item in the first file-list, send 1 more
                         * file-list to check if this is a 1-file xfer. */
                        send_extra_file_list(f, 1);
                }
        }

        return flist;
}

struct file_list *recv_file_list(int f)
{
        struct file_list *flist;
        int dstart, flags;
        int64 start_read;

        if (!first_flist)
                rprintf(FLOG, "receiving file list\n");
        if (show_filelist_p())
                start_filelist_progress("receiving file list");
        else if (inc_recurse && verbose && !am_server && !first_flist)
                rprintf(FCLIENT, "receiving incremental file list\n");

        start_read = stats.total_read;

        flist = flist_new(0, "recv_file_list");

#ifdef SUPPORT_HARD_LINKS
        if (preserve_hard_links && protocol_version < 30)
                init_hard_links();
#endif

        if (inc_recurse) {
                if (flist->ndx_start == 0)
                        dir_flist = flist_new(FLIST_TEMP, "recv_file_list");
                dstart = dir_flist->count;
        } else {
                dir_flist = flist;
                dstart = 0;
        }

        while ((flags = read_byte(f)) != 0) {
                struct file_struct *file;

                flist_expand(flist, 1);

                if (protocol_version >= 28 && (flags & XMIT_EXTENDED_FLAGS))
                        flags |= read_byte(f) << 8;
                file = recv_file_entry(flist, flags, f);

                if (inc_recurse && S_ISDIR(file->mode)) {
                        flist_expand(dir_flist, 1);
                        dir_flist->files[dir_flist->count++] = file;
                }

                flist->files[flist->count++] = file;

                maybe_emit_filelist_progress(flist->count);

                if (verbose > 2) {
                        rprintf(FINFO, "recv_file_name(%s)\n",
                                f_name(file, NULL));
                }
        }
        file_total += flist->count;

        if (verbose > 2)
                rprintf(FINFO, "received %d names\n", flist->count);

        if (show_filelist_p())
                finish_filelist_progress(flist);

#ifdef ICONV_OPTION
        if (need_unsorted_flist) {
                /* Create an extra array of index pointers that we can sort for
                 * the generator's use (for wading through the files in sorted
                 * order and for calling flist_find()).  We keep the "files"
                 * list unsorted for our exchange of index numbers with the
                 * other side (since their names may not sort the same). */
                if (!(flist->sorted = new_array(struct file_struct *, flist->count)))
                        out_of_memory("recv_file_list");
                memcpy(flist->sorted, flist->files,
                       flist->count * sizeof (struct file_struct*));
                if (inc_recurse && dir_flist->count > dstart) {
                        dir_flist->sorted = realloc_array(dir_flist->sorted,
                                                struct file_struct *,
                                                dir_flist->count);
                        memcpy(dir_flist->sorted + dstart, dir_flist->files + dstart,
                               (dir_flist->count - dstart) * sizeof (struct file_struct*));
                        fsort(dir_flist->sorted + dstart, dir_flist->count - dstart);
                }
        } else
#endif
        {
                flist->sorted = flist->files;
                if (inc_recurse && dir_flist->count > dstart) {
                        dir_flist->sorted = dir_flist->files;
                        fsort(dir_flist->sorted + dstart, dir_flist->count - dstart);
                }
        }

        if (inc_recurse)
                flist_done_allocating(flist);
        else if (f >= 0)
                recv_id_list(f, flist);

        clean_flist(flist, relative_paths);

        if (protocol_version < 30) {
                /* Recv the io_error flag */
                if (ignore_errors)
                        read_int(f);
                else
                        io_error |= read_int(f);
        }

        if (verbose > 3)
                output_flist(flist);

        if (list_only) {
                int i;
                for (i = 0; i < flist->count; i++)
                        list_file_entry(flist->files[i]);
        }

        if (verbose > 2)
                rprintf(FINFO, "recv_file_list done\n");

        stats.flist_size += stats.total_read - start_read;
        stats.num_files += flist->count;

        return flist;
}

/* This is only used once by the receiver if the very first file-list
 * has exactly one item in it. */
void recv_additional_file_list(int f)
{
        struct file_list *flist;
        int ndx = read_ndx(f);
        if (ndx == NDX_FLIST_EOF) {
                flist_eof = 1;
                change_local_filter_dir(NULL, 0, 0);
        } else {
                ndx = NDX_FLIST_OFFSET - ndx;
                if (ndx < 0 || ndx >= dir_flist->count) {
                        ndx = NDX_FLIST_OFFSET - ndx;
                        rprintf(FERROR,
                                "[%s] Invalid dir index: %d (%d - %d)\n",
                                who_am_i(), ndx, NDX_FLIST_OFFSET,
                                NDX_FLIST_OFFSET - dir_flist->count + 1);
                        exit_cleanup(RERR_PROTOCOL);
                }
                if (verbose > 3) {
                        rprintf(FINFO, "[%s] receiving flist for dir %d\n",
                                who_am_i(), ndx);
                }
                flist = recv_file_list(f);
                flist->parent_ndx = ndx;
        }
}

/* Search for an identically-named item in the file list.  Note that the
 * items must agree in their directory-ness, or no match is returned. */
int flist_find(struct file_list *flist, struct file_struct *f)
{
        int low = flist->low, high = flist->high;
        int diff, mid, mid_up;

        while (low <= high) {
                mid = (low + high) / 2;
                if (F_IS_ACTIVE(flist->sorted[mid]))
                        mid_up = mid;
                else {
                        /* Scan for the next non-empty entry using the cached
                         * distance values.  If the value isn't fully up-to-
                         * date, update it. */
                        mid_up = mid + F_DEPTH(flist->sorted[mid]);
                        if (!F_IS_ACTIVE(flist->sorted[mid_up])) {
                                do {
                                    mid_up += F_DEPTH(flist->sorted[mid_up]);
                                } while (!F_IS_ACTIVE(flist->sorted[mid_up]));
                                F_DEPTH(flist->sorted[mid]) = mid_up - mid;
                        }
                        if (mid_up > high) {
                                /* If there's nothing left above us, set high to
                                 * a non-empty entry below us and continue. */
                                high = mid - (int)flist->sorted[mid]->len32;
                                if (!F_IS_ACTIVE(flist->sorted[high])) {
                                        do {
                                            high -= (int)flist->sorted[high]->len32;
                                        } while (!F_IS_ACTIVE(flist->sorted[high]));
                                        flist->sorted[mid]->len32 = mid - high;
                                }
                                continue;
                        }
                }
                diff = f_name_cmp(flist->sorted[mid_up], f);
                if (diff == 0) {
                        if (protocol_version < 29
                            && S_ISDIR(flist->sorted[mid_up]->mode)
                            != S_ISDIR(f->mode))
                                return -1;
                        return mid_up;
                }
                if (diff < 0)
                        low = mid_up + 1;
                else
                        high = mid - 1;
        }
        return -1;
}

/*
 * Free up any resources a file_struct has allocated
 * and clear the file.
 */
void clear_file(struct file_struct *file)
{
        /* The +1 zeros out the first char of the basename. */
        memset(file, 0, FILE_STRUCT_LEN + 1);
        /* In an empty entry, F_DEPTH() is an offset to the next non-empty
         * entry.  Likewise for len32 in the opposite direction.  We assume
         * that we're alone for now since flist_find() will adjust the counts
         * it runs into that aren't up-to-date. */
        file->len32 = F_DEPTH(file) = 1;
}

/* Allocate a new file list. */
struct file_list *flist_new(int flags, char *msg)
{
        struct file_list *flist;

        flist = new(struct file_list);
        if (!flist)
                out_of_memory(msg);

        memset(flist, 0, sizeof flist[0]);

        if (flags & FLIST_TEMP) {
                if (!(flist->file_pool = pool_create(SMALL_EXTENT, 0,
                                                out_of_memory, POOL_INTERN)))
                        out_of_memory(msg);
        } else {
                /* This is a doubly linked list with prev looping back to
                 * the end of the list, but the last next pointer is NULL. */
                if (!first_flist) {
                        flist->file_pool = pool_create(NORMAL_EXTENT, 0,
                                                out_of_memory, POOL_INTERN);
                        if (!flist->file_pool)
                                out_of_memory(msg);

                        first_flist = cur_flist = flist->prev = flist;
                } else {
                        flist->file_pool = first_flist->file_pool;

                        flist->ndx_start = first_flist->prev->ndx_start
                                         + first_flist->prev->count;

                        flist->prev = first_flist->prev;
                        flist->prev->next = first_flist->prev = flist;
                }
                flist->pool_boundary = pool_boundary(flist->file_pool, 0);
                flist_cnt++;
        }

        return flist;
}

/* Free up all elements in a flist. */
void flist_free(struct file_list *flist)
{
        if (!flist->prev) {
                /* Was FLIST_TEMP dir-list. */
        } else if (flist == flist->prev) {
                first_flist = cur_flist = NULL;
                file_total = 0;
                flist_cnt = 0;
        } else {
                if (flist == cur_flist)
                        cur_flist = flist->next;
                if (flist == first_flist)
                        first_flist = first_flist->next;
                else {
                        flist->prev->next = flist->next;
                        if (!flist->next)
                                flist->next = first_flist;
                }
                flist->next->prev = flist->prev;
                file_total -= flist->count;
                flist_cnt--;
        }

        if (!flist->prev || !flist_cnt)
                pool_destroy(flist->file_pool);
        else
                pool_free_old(flist->file_pool, flist->pool_boundary);

        if (flist->sorted && flist->sorted != flist->files)
                free(flist->sorted);
        free(flist->files);
        free(flist);
}

/* This routine ensures we don't have any duplicate names in our file list.
 * duplicate names can cause corruption because of the pipelining. */
static void clean_flist(struct file_list *flist, int strip_root)
{
        char fbuf[MAXPATHLEN];
        int i, prev_i;

        if (!flist)
                return;
        if (flist->count == 0) {
                flist->high = -1;
                return;
        }

        fsort(flist->sorted, flist->count);

        if (!am_sender || inc_recurse) {
                for (i = prev_i = 0; i < flist->count; i++) {
                        if (F_IS_ACTIVE(flist->sorted[i])) {
                                prev_i = i;
                                break;
                        }
                }
                flist->low = prev_i;
        } else {
                i = prev_i = flist->count - 1;
                flist->low = 0;
        }

        while (++i < flist->count) {
                int j;
                struct file_struct *file = flist->sorted[i];

                if (!F_IS_ACTIVE(file))
                        continue;
                if (f_name_cmp(file, flist->sorted[prev_i]) == 0)
                        j = prev_i;
                else if (protocol_version >= 29 && S_ISDIR(file->mode)) {
                        int save_mode = file->mode;
                        /* Make sure that this directory doesn't duplicate a
                         * non-directory earlier in the list. */
                        flist->high = prev_i;
                        file->mode = S_IFREG;
                        j = flist_find(flist, file);
                        file->mode = save_mode;
                } else
                        j = -1;
                if (j >= 0) {
                        int keep, drop;
                        /* If one is a dir and the other is not, we want to
                         * keep the dir because it might have contents in the
                         * list. */
                        if (S_ISDIR(file->mode)) {
                                struct file_struct *fp = flist->sorted[j];
                                if (!S_ISDIR(fp->mode))
                                        keep = i, drop = j;
                                else
                                        keep = j, drop = i;
                        } else
                                keep = j, drop = i;

                        if (am_sender)
                                flist->sorted[drop]->flags |= FLAG_DUPLICATE;
                        else {
                                if (verbose > 1) {
                                        rprintf(FINFO,
                                            "removing duplicate name %s from file list (%d)\n",
                                            f_name(file, fbuf), drop + flist->ndx_start);
                                }
                                /* Make sure we don't lose track of a user-specified
                                 * top directory. */
                                flist->sorted[keep]->flags |= flist->sorted[drop]->flags
                                                           & (FLAG_TOP_DIR|FLAG_XFER_DIR);

                                clear_file(flist->sorted[drop]);
                        }

                        if (keep == i) {
                                if (flist->low == drop) {
                                        for (j = drop + 1;
                                             j < i && !F_IS_ACTIVE(flist->sorted[j]);
                                             j++) {}
                                        flist->low = j;
                                }
                                prev_i = i;
                        }
                } else
                        prev_i = i;
        }
        flist->high = prev_i;

        if (strip_root) {
                /* We need to strip off the leading slashes for relative
                 * paths, but this must be done _after_ the sorting phase. */
                for (i = flist->low; i <= flist->high; i++) {
                        struct file_struct *file = flist->sorted[i];

                        if (!file->dirname)
                                continue;
                        while (*file->dirname == '/')
                                file->dirname++;
                        if (!*file->dirname)
                                file->dirname = NULL;
                }
        }

        if (prune_empty_dirs && !am_sender) {
                int j, prev_depth = 0;

                prev_i = 0; /* It's OK that this isn't really true. */

                for (i = flist->low; i <= flist->high; i++) {
                        struct file_struct *fp, *file = flist->sorted[i];

                        /* This temporarily abuses the F_DEPTH() value for a
                         * directory that is in a chain that might get pruned.
                         * We restore the old value if it gets a reprieve. */
                        if (S_ISDIR(file->mode) && F_DEPTH(file)) {
                                /* Dump empty dirs when coming back down. */
                                for (j = prev_depth; j >= F_DEPTH(file); j--) {
                                        fp = flist->sorted[prev_i];
                                        if (F_DEPTH(fp) >= 0)
                                                break;
                                        prev_i = -F_DEPTH(fp)-1;
                                        clear_file(fp);
                                }
                                prev_depth = F_DEPTH(file);
                                if (is_excluded(f_name(file, fbuf), 1,
                                                       ALL_FILTERS)) {
                                        /* Keep dirs through this dir. */
                                        for (j = prev_depth-1; ; j--) {
                                                fp = flist->sorted[prev_i];
                                                if (F_DEPTH(fp) >= 0)
                                                        break;
                                                prev_i = -F_DEPTH(fp)-1;
                                                F_DEPTH(fp) = j;
                                        }
                                } else
                                        F_DEPTH(file) = -prev_i-1;
                                prev_i = i;
                        } else {
                                /* Keep dirs through this non-dir. */
                                for (j = prev_depth; ; j--) {
                                        fp = flist->sorted[prev_i];
                                        if (F_DEPTH(fp) >= 0)
                                                break;
                                        prev_i = -F_DEPTH(fp)-1;
                                        F_DEPTH(fp) = j;
                                }
                        }
                }
                /* Dump all remaining empty dirs. */
                while (1) {
                        struct file_struct *fp = flist->sorted[prev_i];
                        if (F_DEPTH(fp) >= 0)
                                break;
                        prev_i = -F_DEPTH(fp)-1;
                        clear_file(fp);
                }

                for (i = flist->low; i <= flist->high; i++) {
                        if (F_IS_ACTIVE(flist->sorted[i]))
                                break;
                }
                flist->low = i;
                for (i = flist->high; i >= flist->low; i--) {
                        if (F_IS_ACTIVE(flist->sorted[i]))
                                break;
                }
                flist->high = i;
        }
}

static void output_flist(struct file_list *flist)
{
        char uidbuf[16], gidbuf[16], depthbuf[16];
        struct file_struct *file;
        const char *root, *dir, *slash, *name, *trail;
        const char *who = who_am_i();
        int i;

        rprintf(FINFO, "[%s] flist start=%d, count=%d, low=%d, high=%d\n",
                who, flist->ndx_start, flist->count, flist->low, flist->high);
        for (i = 0; i < flist->count; i++) {
                file = flist->sorted[i];
                if ((am_root || am_sender) && uid_ndx) {
                        snprintf(uidbuf, sizeof uidbuf, " uid=%u",
                                 F_OWNER(file));
                } else
                        *uidbuf = '\0';
                if (gid_ndx) {
                        static char parens[] = "(\0)\0\0\0";
                        char *pp = parens + (file->flags & FLAG_SKIP_GROUP ? 0 : 3);
                        snprintf(gidbuf, sizeof gidbuf, " gid=%s%u%s",
                                 pp, F_GROUP(file), pp + 2);
                } else
                        *gidbuf = '\0';
                if (!am_sender)
                        snprintf(depthbuf, sizeof depthbuf, "%d", F_DEPTH(file));
                if (F_IS_ACTIVE(file)) {
                        root = am_sender ? NS(F_PATHNAME(file)) : depthbuf;
                        if ((dir = file->dirname) == NULL)
                                dir = slash = "";
                        else
                                slash = "/";
                        name = file->basename;
                        trail = S_ISDIR(file->mode) ? "/" : "";
                } else
                        root = dir = slash = name = trail = "";
                rprintf(FINFO,
                        "[%s] i=%d %s %s%s%s%s mode=0%o len=%.0f%s%s flags=%x\n",
                        who, i + flist->ndx_start,
                        root, dir, slash, name, trail,
                        (int)file->mode, (double)F_LENGTH(file),
                        uidbuf, gidbuf, file->flags);
        }
}

enum fnc_state { s_DIR, s_SLASH, s_BASE, s_TRAILING };
enum fnc_type { t_PATH, t_ITEM };

/* Compare the names of two file_struct entities, similar to how strcmp()
 * would do if it were operating on the joined strings.
 *
 * Some differences beginning with protocol_version 29: (1) directory names
 * are compared with an assumed trailing slash so that they compare in a
 * way that would cause them to sort immediately prior to any content they
 * may have; (2) a directory of any name compares after a non-directory of
 * any name at the same depth; (3) a directory with name "." compares prior
 * to anything else.  These changes mean that a directory and a non-dir
 * with the same name will not compare as equal (protocol_version >= 29).
 *
 * The dirname component can be an empty string, but the basename component
 * cannot (and never is in the current codebase).  The basename component
 * may be NULL (for a removed item), in which case it is considered to be
 * after any existing item. */
int f_name_cmp(struct file_struct *f1, struct file_struct *f2)
{
        int dif;
        const uchar *c1, *c2;
        enum fnc_state state1, state2;
        enum fnc_type type1, type2;
        enum fnc_type t_path = protocol_version >= 29 ? t_PATH : t_ITEM;

        if (!f1 || !F_IS_ACTIVE(f1)) {
                if (!f2 || !F_IS_ACTIVE(f2))
                        return 0;
                return -1;
        }
        if (!f2 || !F_IS_ACTIVE(f2))
                return 1;

        c1 = (uchar*)f1->dirname;
        c2 = (uchar*)f2->dirname;
        if (c1 == c2)
                c1 = c2 = NULL;
        if (!c1) {
                type1 = S_ISDIR(f1->mode) ? t_path : t_ITEM;
                c1 = (const uchar*)f1->basename;
                if (type1 == t_PATH && *c1 == '.' && !c1[1]) {
                        type1 = t_ITEM;
                        state1 = s_TRAILING;
                        c1 = (uchar*)"";
                } else
                        state1 = s_BASE;
        } else {
                type1 = t_path;
                state1 = s_DIR;
        }
        if (!c2) {
                type2 = S_ISDIR(f2->mode) ? t_path : t_ITEM;
                c2 = (const uchar*)f2->basename;
                if (type2 == t_PATH && *c2 == '.' && !c2[1]) {
                        type2 = t_ITEM;
                        state2 = s_TRAILING;
                        c2 = (uchar*)"";
                } else
                        state2 = s_BASE;
        } else {
                type2 = t_path;
                state2 = s_DIR;
        }

        if (type1 != type2)
                return type1 == t_PATH ? 1 : -1;

        do {
                if (!*c1) {
                        switch (state1) {
                        case s_DIR:
                                state1 = s_SLASH;
                                c1 = (uchar*)"/";
                                break;
                        case s_SLASH:
                                type1 = S_ISDIR(f1->mode) ? t_path : t_ITEM;
                                c1 = (const uchar*)f1->basename;
                                if (type1 == t_PATH && *c1 == '.' && !c1[1]) {
                                        type1 = t_ITEM;
                                        state1 = s_TRAILING;
                                        c1 = (uchar*)"";
                                } else
                                        state1 = s_BASE;
                                break;
                        case s_BASE:
                                state1 = s_TRAILING;
                                if (type1 == t_PATH) {
                                        c1 = (uchar*)"/";
                                        break;
                                }
                                /* FALL THROUGH */
                        case s_TRAILING:
                                type1 = t_ITEM;
                                break;
                        }
                        if (*c2 && type1 != type2)
                                return type1 == t_PATH ? 1 : -1;
                }
                if (!*c2) {
                        switch (state2) {
                        case s_DIR:
                                state2 = s_SLASH;
                                c2 = (uchar*)"/";
                                break;
                        case s_SLASH:
                                type2 = S_ISDIR(f2->mode) ? t_path : t_ITEM;
                                c2 = (const uchar*)f2->basename;
                                if (type2 == t_PATH && *c2 == '.' && !c2[1]) {
                                        type2 = t_ITEM;
                                        state2 = s_TRAILING;
                                        c2 = (uchar*)"";
                                } else
                                        state2 = s_BASE;
                                break;
                        case s_BASE:
                                state2 = s_TRAILING;
                                if (type2 == t_PATH) {
                                        c2 = (uchar*)"/";
                                        break;
                                }
                                /* FALL THROUGH */
                        case s_TRAILING:
                                if (!*c1)
                                        return 0;
                                type2 = t_ITEM;
                                break;
                        }
                        if (type1 != type2)
                                return type1 == t_PATH ? 1 : -1;
                }
        } while ((dif = (int)*c1++ - (int)*c2++) == 0);

        return dif;
}

char *f_name_buf(void)
{
        static char names[5][MAXPATHLEN];
        static unsigned int n;

        n = (n + 1) % (sizeof names / sizeof names[0]);

        return names[n];
}

/* Return a copy of the full filename of a flist entry, using the indicated
 * buffer or one of 5 static buffers if fbuf is NULL.  No size-checking is
 * done because we checked the size when creating the file_struct entry.
 */
char *f_name(struct file_struct *f, char *fbuf)
{
        if (!f || !F_IS_ACTIVE(f))
                return NULL;

        if (!fbuf)
                fbuf = f_name_buf();

        if (f->dirname) {
                int len = strlen(f->dirname);
                memcpy(fbuf, f->dirname, len);
                fbuf[len] = '/';
                strlcpy(fbuf + len + 1, f->basename, MAXPATHLEN - (len + 1));
        } else
                strlcpy(fbuf, f->basename, MAXPATHLEN);

        return fbuf;
}

/* Do a non-recursive scan of the named directory, possibly ignoring all
 * exclude rules except for the daemon's.  If "dlen" is >=0, it is the length
 * of the dirname string, and also indicates that "dirname" is a MAXPATHLEN
 * buffer (the functions we call will append names onto the end, but the old
 * dir value will be restored on exit). */
struct file_list *get_dirlist(char *dirname, int dlen, int ignore_filter_rules)
{
        struct file_list *dirlist;
        char dirbuf[MAXPATHLEN];
        int save_recurse = recurse;
        int save_xfer_dirs = xfer_dirs;

        if (dlen < 0) {
                dlen = strlcpy(dirbuf, dirname, MAXPATHLEN);
                if (dlen >= MAXPATHLEN)
                        return NULL;
                dirname = dirbuf;
        }

        dirlist = flist_new(FLIST_TEMP, "get_dirlist");

        recurse = 0;
        xfer_dirs = 1;
        send_directory(ignore_filter_rules ? -2 : -1, dirlist, dirname, dlen, 0);
        xfer_dirs = save_xfer_dirs;
        recurse = save_recurse;
        if (do_progress)
                flist_count_offset += dirlist->count;

        dirlist->sorted = dirlist->files;
        clean_flist(dirlist, 0);

        if (verbose > 3)
                output_flist(dirlist);

        return dirlist;
}