- Added set_io_timeout(), which sets all the timeout-dependent

[rsync.git] / util.c

/*  -*- c-file-style: "linux" -*-
 *
 * Copyright (C) 1996-2000 by Andrew Tridgell
 * Copyright (C) Paul Mackerras 1996
 * Copyright (C) 2001, 2002 by Martin Pool <mbp@samba.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/**
 * @file
 *
 * Utilities used in rsync
 **/

#include "rsync.h"

extern int verbose;
extern int dry_run;
extern int module_id;
extern int modify_window;
extern char *partial_dir;
extern struct filter_list_struct server_filter_list;

int sanitize_paths = 0;



/**
 * Set a fd into nonblocking mode
 **/
void set_nonblocking(int fd)
{
        int val;

        if ((val = fcntl(fd, F_GETFL, 0)) == -1)
                return;
        if (!(val & NONBLOCK_FLAG)) {
                val |= NONBLOCK_FLAG;
                fcntl(fd, F_SETFL, val);
        }
}

/**
 * Set a fd into blocking mode
 **/
void set_blocking(int fd)
{
        int val;

        if ((val = fcntl(fd, F_GETFL, 0)) == -1)
                return;
        if (val & NONBLOCK_FLAG) {
                val &= ~NONBLOCK_FLAG;
                fcntl(fd, F_SETFL, val);
        }
}


/**
 * Create a file descriptor pair - like pipe() but use socketpair if
 * possible (because of blocking issues on pipes).
 *
 * Always set non-blocking.
 */
int fd_pair(int fd[2])
{
        int ret;

#ifdef HAVE_SOCKETPAIR
        ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fd);
#else
        ret = pipe(fd);
#endif

        if (ret == 0) {
                set_nonblocking(fd[0]);
                set_nonblocking(fd[1]);
        }

        return ret;
}


void print_child_argv(char **cmd)
{
        rprintf(FINFO, "opening connection using ");
        for (; *cmd; cmd++) {
                /* Look for characters that ought to be quoted.  This
                * is not a great quoting algorithm, but it's
                * sufficient for a log message. */
                if (strspn(*cmd, "abcdefghijklmnopqrstuvwxyz"
                           "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
                           "0123456789"
                           ",.-_=+@/") != strlen(*cmd)) {
                        rprintf(FINFO, "\"%s\" ", safe_fname(*cmd));
                } else {
                        rprintf(FINFO, "%s ", safe_fname(*cmd));
                }
        }
        rprintf(FINFO, "\n");
}


void out_of_memory(char *str)
{
        rprintf(FERROR, "ERROR: out of memory in %s\n", str);
        exit_cleanup(RERR_MALLOC);
}

void overflow(char *str)
{
        rprintf(FERROR, "ERROR: buffer overflow in %s\n", str);
        exit_cleanup(RERR_MALLOC);
}



int set_modtime(char *fname, time_t modtime)
{
        if (verbose > 2) {
                rprintf(FINFO, "set modtime of %s to (%ld) %s",
                        safe_fname(fname), (long)modtime,
                        asctime(localtime(&modtime)));
        }

        if (dry_run)
                return 0;

        {
#ifdef HAVE_UTIMBUF
                struct utimbuf tbuf;
                tbuf.actime = time(NULL);
                tbuf.modtime = modtime;
                return utime(fname,&tbuf);
#elif defined HAVE_UTIME
                time_t t[2];
                t[0] = time(NULL);
                t[1] = modtime;
                return utime(fname,t);
#else
                struct timeval t[2];
                t[0].tv_sec = time(NULL);
                t[0].tv_usec = 0;
                t[1].tv_sec = modtime;
                t[1].tv_usec = 0;
                return utimes(fname,t);
#endif
        }
}


/**
   Create any necessary directories in fname. Unfortunately we don't know
   what perms to give the directory when this is called so we need to rely
   on the umask
**/
int create_directory_path(char *fname, int base_umask)
{
        char *p;

        while (*fname == '/')
                fname++;
        while (strncmp(fname, "./", 2) == 0)
                fname += 2;

        p = fname;
        while ((p = strchr(p,'/')) != NULL) {
                *p = 0;
                do_mkdir(fname, 0777 & ~base_umask);
                *p = '/';
                p++;
        }
        return 0;
}


/**
 * Write @p len bytes at @p ptr to descriptor @p desc, retrying if
 * interrupted.
 *
 * @retval len upon success
 *
 * @retval <0 write's (negative) error code
 *
 * Derived from GNU C's cccp.c.
 */
int full_write(int desc, char *ptr, size_t len)
{
        int total_written;

        total_written = 0;
        while (len > 0) {
                int written = write(desc, ptr, len);
                if (written < 0)  {
                        if (errno == EINTR)
                                continue;
                        return written;
                }
                total_written += written;
                ptr += written;
                len -= written;
        }
        return total_written;
}


/**
 * Read @p len bytes at @p ptr from descriptor @p desc, retrying if
 * interrupted.
 *
 * @retval >0 the actual number of bytes read
 *
 * @retval 0 for EOF
 *
 * @retval <0 for an error.
 *
 * Derived from GNU C's cccp.c. */
static int safe_read(int desc, char *ptr, size_t len)
{
        int n_chars;

        if (len == 0)
                return len;

        do {
                n_chars = read(desc, ptr, len);
        } while (n_chars < 0 && errno == EINTR);

        return n_chars;
}


/** Copy a file.
 *
 * This is used in conjunction with the --temp-dir, --backup, and
 * --copy-dest options. */
int copy_file(char *source, char *dest, mode_t mode)
{
        int ifd;
        int ofd;
        char buf[1024 * 8];
        int len;   /* Number of bytes read into `buf'. */

        ifd = do_open(source, O_RDONLY, 0);
        if (ifd == -1) {
                rsyserr(FERROR, errno, "open %s", full_fname(source));
                return -1;
        }

        if (robust_unlink(dest) && errno != ENOENT) {
                rsyserr(FERROR, errno, "unlink %s", full_fname(dest));
                return -1;
        }

        ofd = do_open(dest, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, mode);
        if (ofd == -1) {
                rsyserr(FERROR, errno, "open %s", full_fname(dest));
                close(ifd);
                return -1;
        }

        while ((len = safe_read(ifd, buf, sizeof buf)) > 0) {
                if (full_write(ofd, buf, len) < 0) {
                        rsyserr(FERROR, errno, "write %s", full_fname(dest));
                        close(ifd);
                        close(ofd);
                        return -1;
                }
        }

        if (len < 0) {
                rsyserr(FERROR, errno, "read %s", full_fname(source));
                close(ifd);
                close(ofd);
                return -1;
        }

        if (close(ifd) < 0) {
                rsyserr(FINFO, errno, "close failed on %s",
                        full_fname(source));
        }

        if (close(ofd) < 0) {
                rsyserr(FERROR, errno, "close failed on %s",
                        full_fname(dest));
                return -1;
        }

        return 0;
}

/* MAX_RENAMES should be 10**MAX_RENAMES_DIGITS */
#define MAX_RENAMES_DIGITS 3
#define MAX_RENAMES 1000

/**
 * Robust unlink: some OS'es (HPUX) refuse to unlink busy files, so
 * rename to <path>/.rsyncNNN instead.
 *
 * Note that successive rsync runs will shuffle the filenames around a
 * bit as long as the file is still busy; this is because this function
 * does not know if the unlink call is due to a new file coming in, or
 * --delete trying to remove old .rsyncNNN files, hence it renames it
 * each time.
 **/
int robust_unlink(char *fname)
{
#ifndef ETXTBSY
        return do_unlink(fname);
#else
        static int counter = 1;
        int rc, pos, start;
        char path[MAXPATHLEN];

        rc = do_unlink(fname);
        if (rc == 0 || errno != ETXTBSY)
                return rc;

        if ((pos = strlcpy(path, fname, MAXPATHLEN)) >= MAXPATHLEN)
                pos = MAXPATHLEN - 1;

        while (pos > 0 && path[pos-1] != '/')
                pos--;
        pos += strlcpy(path+pos, ".rsync", MAXPATHLEN-pos);

        if (pos > (MAXPATHLEN-MAX_RENAMES_DIGITS-1)) {
                errno = ETXTBSY;
                return -1;
        }

        /* start where the last one left off to reduce chance of clashes */
        start = counter;
        do {
                sprintf(&path[pos], "%03d", counter);
                if (++counter >= MAX_RENAMES)
                        counter = 1;
        } while ((rc = access(path, 0)) == 0 && counter != start);

        if (verbose > 0) {
                rprintf(FINFO,"renaming %s to %s because of text busy\n",
                        safe_fname(fname), safe_fname(path));
        }

        /* maybe we should return rename()'s exit status? Nah. */
        if (do_rename(fname, path) != 0) {
                errno = ETXTBSY;
                return -1;
        }
        return 0;
#endif
}

/* Returns 0 on successful rename, 1 if we successfully copied the file
 * across filesystems, -2 if copy_file() failed, and -1 on other errors. */
int robust_rename(char *from, char *to, int mode)
{
        int tries = 4;

        while (tries--) {
                if (do_rename(from, to) == 0)
                        return 0;

                switch (errno) {
#ifdef ETXTBSY
                case ETXTBSY:
                        if (robust_unlink(to) != 0)
                                return -1;
                        break;
#endif
                case EXDEV:
                        if (copy_file(from, to, mode) != 0)
                                return -2;
                        do_unlink(from);
                        return 1;
                default:
                        return -1;
                }
        }
        return -1;
}


static pid_t all_pids[10];
static int num_pids;

/** Fork and record the pid of the child. **/
pid_t do_fork(void)
{
        pid_t newpid = fork();

        if (newpid != 0  &&  newpid != -1) {
                all_pids[num_pids++] = newpid;
        }
        return newpid;
}

/**
 * Kill all children.
 *
 * @todo It would be kind of nice to make sure that they are actually
 * all our children before we kill them, because their pids may have
 * been recycled by some other process.  Perhaps when we wait for a
 * child, we should remove it from this array.  Alternatively we could
 * perhaps use process groups, but I think that would not work on
 * ancient Unix versions that don't support them.
 **/
void kill_all(int sig)
{
        int i;

        for (i = 0; i < num_pids; i++) {
                /* Let's just be a little careful where we
                 * point that gun, hey?  See kill(2) for the
                 * magic caused by negative values. */
                pid_t p = all_pids[i];

                if (p == getpid())
                        continue;
                if (p <= 0)
                        continue;

                kill(p, sig);
        }
}


/** Turn a user name into a uid */
int name_to_uid(char *name, uid_t *uid)
{
        struct passwd *pass;
        if (!name || !*name)
                return 0;
        pass = getpwnam(name);
        if (pass) {
                *uid = pass->pw_uid;
                return 1;
        }
        return 0;
}

/** Turn a group name into a gid */
int name_to_gid(char *name, gid_t *gid)
{
        struct group *grp;
        if (!name || !*name)
                return 0;
        grp = getgrnam(name);
        if (grp) {
                *gid = grp->gr_gid;
                return 1;
        }
        return 0;
}


/** Lock a byte range in a open file */
int lock_range(int fd, int offset, int len)
{
        struct flock lock;

        lock.l_type = F_WRLCK;
        lock.l_whence = SEEK_SET;
        lock.l_start = offset;
        lock.l_len = len;
        lock.l_pid = 0;

        return fcntl(fd,F_SETLK,&lock) == 0;
}

static int filter_server_path(char *arg)
{
        char *s;

        if (server_filter_list.head) {
                for (s = arg; (s = strchr(s, '/')) != NULL; ) {
                        *s = '\0';
                        if (check_filter(&server_filter_list, arg, 1) < 0) {
                                /* We must leave arg truncated! */
                                return 1;
                        }
                        *s++ = '/';
                }
        }
        return 0;
}

static void glob_expand_one(char *s, char ***argv_ptr, int *argc_ptr,
                            int *maxargs_ptr)
{
        char **argv = *argv_ptr;
        int argc = *argc_ptr;
        int maxargs = *maxargs_ptr;
#if !defined HAVE_GLOB || !defined HAVE_GLOB_H
        if (argc == maxargs) {
                maxargs += MAX_ARGS;
                if (!(argv = realloc_array(argv, char *, maxargs)))
                        out_of_memory("glob_expand_one");
                *argv_ptr = argv;
                *maxargs_ptr = maxargs;
        }
        if (!*s)
                s = ".";
        s = argv[argc++] = strdup(s);
        filter_server_path(s);
#else
        glob_t globbuf;
        int i;

        if (maxargs <= argc)
                return;
        if (!*s)
                s = ".";

        if (sanitize_paths)
                s = sanitize_path(NULL, s, "", 0);
        else
                s = strdup(s);

        memset(&globbuf, 0, sizeof globbuf);
        if (!filter_server_path(s))
                glob(s, 0, NULL, &globbuf);
        if (MAX((int)globbuf.gl_pathc, 1) > maxargs - argc) {
                maxargs += globbuf.gl_pathc + MAX_ARGS;
                if (!(argv = realloc_array(argv, char *, maxargs)))
                        out_of_memory("glob_expand_one");
                *argv_ptr = argv;
                *maxargs_ptr = maxargs;
        }
        if (globbuf.gl_pathc == 0)
                argv[argc++] = s;
        else {
                int j = globbuf.gl_pathc;
                free(s);
                for (i = 0; i < j; i++) {
                        if (!(argv[argc++] = strdup(globbuf.gl_pathv[i])))
                                out_of_memory("glob_expand_one");
                }
        }
        globfree(&globbuf);
#endif
        *argc_ptr = argc;
}

/* This routine is only used in daemon mode. */
void glob_expand(char *base1, char ***argv_ptr, int *argc_ptr, int *maxargs_ptr)
{
        char *s = (*argv_ptr)[*argc_ptr];
        char *p, *q;
        char *base = base1;
        int base_len = strlen(base);

        if (!s || !*s)
                return;

        if (strncmp(s, base, base_len) == 0)
                s += base_len;

        if (!(s = strdup(s)))
                out_of_memory("glob_expand");

        if (asprintf(&base," %s/", base1) <= 0)
                out_of_memory("glob_expand");
        base_len++;

        for (q = s; *q; q = p + base_len) {
                if ((p = strstr(q, base)) != NULL)
                        *p = '\0'; /* split it at this point */
                glob_expand_one(q, argv_ptr, argc_ptr, maxargs_ptr);
                if (!p)
                        break;
        }

        free(s);
        free(base);
}

/**
 * Convert a string to lower case
 **/
void strlower(char *s)
{
        while (*s) {
                if (isupper(*(unsigned char *)s))
                        *s = tolower(*(unsigned char *)s);
                s++;
        }
}

/* Join strings p1 & p2 into "dest" with a guaranteed '/' between them.  (If
 * p1 ends with a '/', no extra '/' is inserted.)  Returns the length of both
 * strings + 1 (if '/' was inserted), regardless of whether the null-terminated
 * string fits into destsize. */
size_t pathjoin(char *dest, size_t destsize, const char *p1, const char *p2)
{
        size_t len = strlcpy(dest, p1, destsize);
        if (len < destsize - 1) {
                if (!len || dest[len-1] != '/')
                        dest[len++] = '/';
                if (len < destsize - 1)
                        len += strlcpy(dest + len, p2, destsize - len);
                else {
                        dest[len] = '\0';
                        len += strlen(p2);
                }
        }
        else
                len += strlen(p2) + 1; /* Assume we'd insert a '/'. */
        return len;
}

/* Join any number of strings together, putting them in "dest".  The return
 * value is the length of all the strings, regardless of whether the null-
 * terminated whole fits in destsize.  Your list of string pointers must end
 * with a NULL to indicate the end of the list. */
size_t stringjoin(char *dest, size_t destsize, ...)
{
        va_list ap;
        size_t len, ret = 0;
        const char *src;

        va_start(ap, destsize);
        while (1) {
                if (!(src = va_arg(ap, const char *)))
                        break;
                len = strlen(src);
                ret += len;
                if (destsize > 1) {
                        if (len >= destsize)
                                len = destsize - 1;
                        memcpy(dest, src, len);
                        destsize -= len;
                        dest += len;
                }
        }
        *dest = '\0';
        va_end(ap);

        return ret;
}

int count_dir_elements(const char *p)
{
        int cnt = 0, new_component = 1;
        while (*p) {
                if (*p++ == '/')
                        new_component = 1;
                else if (new_component) {
                        new_component = 0;
                        cnt++;
                }
        }
        return cnt;
}

/* Turns multiple adjacent slashes into a single slash, gets rid of "./"
 * elements (but not a trailing dot dir), removes a trailing slash, and
 * optionally collapses ".." elements (except for those at the start of the
 * string).  If the resulting name would be empty, change it into a ".". */
unsigned int clean_fname(char *name, BOOL collapse_dot_dot)
{
        char *limit = name - 1, *t = name, *f = name;
        int anchored;

        if (!name)
                return 0;

        if ((anchored = *f == '/') != 0)
                *t++ = *f++;
        while (*f) {
                /* discard extra slashes */
                if (*f == '/') {
                        f++;
                        continue;
                }
                if (*f == '.') {
                        /* discard "." dirs (but NOT a trailing '.'!) */
                        if (f[1] == '/') {
                                f += 2;
                                continue;
                        }
                        /* collapse ".." dirs */
                        if (collapse_dot_dot
                            && f[1] == '.' && (f[2] == '/' || !f[2])) {
                                char *s = t - 1;
                                if (s == name && anchored) {
                                        f += 2;
                                        continue;
                                }
                                while (s > limit && *--s != '/') {}
                                if (s != t - 1 && (s < name || *s == '/')) {
                                        t = s + 1;
                                        f += 2;
                                        continue;
                                }
                                limit = t + 2;
                        }
                }
                while (*f && (*t++ = *f++) != '/') {}
        }

        if (t > name+anchored && t[-1] == '/')
                t--;
        if (t == name)
                *t++ = '.';
        *t = '\0';

        return t - name;
}

/* Make path appear as if a chroot had occurred.  This handles a leading
 * "/" (either removing it or expanding it) and any leading or embedded
 * ".." components that attempt to escape past the module's top dir.
 *
 * If dest is NULL, a buffer is allocated to hold the result.  It is legal
 * to call with the dest and the path (p) pointing to the same buffer, but
 * rootdir will be ignored to avoid expansion of the string.
 *
 * The rootdir string contains a value to use in place of a leading slash.
 * Specify NULL to get the default of lp_path(module_id).
 *
 * If depth is >= 0, it is a count of how many '..'s to allow at the start
 * of the path.  Use -1 to allow unlimited depth.
 *
 * We also clean the path in a manner similar to clean_fname() but with a
 * few differences: 
 *
 * Turns multiple adjacent slashes into a single slash, gets rid of "." dir
 * elements (INCLUDING a trailing dot dir), PRESERVES a trailing slash, and
 * ALWAYS collapses ".." elements (except for those at the start of the
 * string up to "depth" deep).  If the resulting name would be empty,
 * change it into a ".". */
char *sanitize_path(char *dest, const char *p, const char *rootdir, int depth)
{
        char *start, *sanp;
        int rlen = 0;

        if (dest != p) {
                int plen = strlen(p);
                if (*p == '/') {
                        if (!rootdir)
                                rootdir = lp_path(module_id);
                        rlen = strlen(rootdir);
                        depth = 0;
                        p++;
                }
                if (dest) {
                        if (rlen + plen + 1 >= MAXPATHLEN)
                                return NULL;
                } else if (!(dest = new_array(char, rlen + plen + 1)))
                        out_of_memory("sanitize_path");
                if (rlen) {
                        memcpy(dest, rootdir, rlen);
                        if (rlen > 1)
                                dest[rlen++] = '/';
                }
        }

        start = sanp = dest + rlen;
        while (*p != '\0') {
                /* discard leading or extra slashes */
                if (*p == '/') {
                        p++;
                        continue;
                }
                /* this loop iterates once per filename component in p.
                 * both p (and sanp if the original had a slash) should
                 * always be left pointing after a slash
                 */
                if (*p == '.' && (p[1] == '/' || p[1] == '\0')) {
                        /* skip "." component */
                        p++;
                        continue;
                }
                if (*p == '.' && p[1] == '.' && (p[2] == '/' || p[2] == '\0')) {
                        /* ".." component followed by slash or end */
                        if (depth <= 0 || sanp != start) {
                                p += 2;
                                if (sanp != start) {
                                        /* back up sanp one level */
                                        --sanp; /* now pointing at slash */
                                        while (sanp > start && sanp[-1] != '/') {
                                                /* skip back up to slash */
                                                sanp--;
                                        }
                                }
                                continue;
                        }
                        /* allow depth levels of .. at the beginning */
                        depth--;
                        /* move the virtual beginning to leave the .. alone */
                        start = sanp + 3;
                }
                /* copy one component through next slash */
                while (*p && (*sanp++ = *p++) != '/') {}
        }
        if (sanp == dest) {
                /* ended up with nothing, so put in "." component */
                *sanp++ = '.';
        }
        *sanp = '\0';

        return dest;
}

char curr_dir[MAXPATHLEN];
unsigned int curr_dir_len;

/**
 * Like chdir(), but it keeps track of the current directory (in the
 * global "curr_dir"), and ensures that the path size doesn't overflow.
 * Also cleans the path using the clean_fname() function.
 **/
int push_dir(char *dir)
{
        static int initialised;
        unsigned int len;

        if (!initialised) {
                initialised = 1;
                getcwd(curr_dir, sizeof curr_dir - 1);
                curr_dir_len = strlen(curr_dir);
        }

        if (!dir)       /* this call was probably just to initialize */
                return 0;

        len = strlen(dir);
        if (len == 1 && *dir == '.')
                return 1;

        if ((*dir == '/' ? len : curr_dir_len + 1 + len) >= sizeof curr_dir)
                return 0;

        if (chdir(dir))
                return 0;

        if (*dir == '/') {
                memcpy(curr_dir, dir, len + 1);
                curr_dir_len = len;
        } else {
                curr_dir[curr_dir_len++] = '/';
                memcpy(curr_dir + curr_dir_len, dir, len + 1);
                curr_dir_len += len;
        }

        curr_dir_len = clean_fname(curr_dir, 1);

        return 1;
}

/**
 * Reverse a push_dir() call.  You must pass in an absolute path
 * that was copied from a prior value of "curr_dir".
 **/
int pop_dir(char *dir)
{
        if (chdir(dir))
                return 0;

        curr_dir_len = strlcpy(curr_dir, dir, sizeof curr_dir);
        if (curr_dir_len >= sizeof curr_dir)
                curr_dir_len = sizeof curr_dir - 1;

        return 1;
}

/* Return the filename, turning any non-printable characters into escaped
 * characters (e.g. \n -> \012, \ -> \\).  This ensures that outputting it
 * cannot generate an empty line nor corrupt the screen.  This function can
 * return only MAX_SAFE_NAMES values at a time!  The returned value can be
 * longer than MAXPATHLEN (because we may be trying to output an error about
 * a too-long filename)! */
char *safe_fname(const char *fname)
{
#define MAX_SAFE_NAMES 4
        static char fbuf[MAX_SAFE_NAMES][MAXPATHLEN*2];
        static int ndx = 0;
        int limit = sizeof fbuf / MAX_SAFE_NAMES - 1;
        char *t;

        ndx = (ndx + 1) % MAX_SAFE_NAMES;
        for (t = fbuf[ndx]; *fname; fname++) {
                if (*fname == '\\') {
                        if ((limit -= 2) < 0)
                                break;
                        *t++ = '\\';
                        *t++ = '\\';
                } else if (!isprint(*(uchar*)fname)) {
                        if ((limit -= 4) < 0)
                                break;
                        sprintf(t, "\\%03o", *(uchar*)fname);
                        t += 4;
                } else {
                        if (--limit < 0)
                                break;
                        *t++ = *fname;
                }
        }
        *t = '\0';

        return fbuf[ndx];
}

/**
 * Return a quoted string with the full pathname of the indicated filename.
 * The string " (in MODNAME)" may also be appended.  The returned pointer
 * remains valid until the next time full_fname() is called.
 **/
char *full_fname(const char *fn)
{
        static char *result = NULL;
        char *m1, *m2, *m3;
        char *p1, *p2;

        if (result)
                free(result);

        fn = safe_fname(fn);
        if (*fn == '/')
                p1 = p2 = "";
        else {
                p1 = curr_dir;
                for (p2 = p1; *p2 == '/'; p2++) {}
                if (*p2)
                        p2 = "/";
        }
        if (module_id >= 0) {
                m1 = " (in ";
                m2 = lp_name(module_id);
                m3 = ")";
                if (p1 == curr_dir) {
                        if (!lp_use_chroot(module_id)) {
                                char *p = lp_path(module_id);
                                if (*p != '/' || p[1])
                                        p1 += strlen(p);
                        }
                }
        } else
                m1 = m2 = m3 = "";

        asprintf(&result, "\"%s%s%s\"%s%s%s", p1, p2, fn, m1, m2, m3);

        return result;
}

static char partial_fname[MAXPATHLEN];

char *partial_dir_fname(const char *fname)
{
        char *t = partial_fname;
        int sz = sizeof partial_fname;
        const char *fn;

        if ((fn = strrchr(fname, '/')) != NULL) {
                fn++;
                if (*partial_dir != '/') {
                        int len = fn - fname;
                        strncpy(t, fname, len); /* safe */
                        t += len;
                        sz -= len;
                }
        } else
                fn = fname;
        if ((int)pathjoin(t, sz, partial_dir, fn) >= sz)
                return NULL;
        if (server_filter_list.head) {
                static int len;
                if (!len)
                        len = strlen(partial_dir);
                t[len] = '\0';
                if (check_filter(&server_filter_list, partial_fname, 1) < 0)
                        return NULL;
                t[len] = '/';
                if (check_filter(&server_filter_list, partial_fname, 0) < 0)
                        return NULL;
        }

        return partial_fname;
}

/* If no --partial-dir option was specified, we don't need to do anything
 * (the partial-dir is essentially '.'), so just return success. */
int handle_partial_dir(const char *fname, int create)
{
        char *fn, *dir;

        if (fname != partial_fname)
                return 1;
        if (!create && *partial_dir == '/')
                return 1;
        if (!(fn = strrchr(partial_fname, '/')))
                return 1;

        *fn = '\0';
        dir = partial_fname;
        if (create) {
                STRUCT_STAT st;
                int statret = do_lstat(dir, &st);
                if (statret == 0 && !S_ISDIR(st.st_mode)) {
                        if (do_unlink(dir) < 0)
                                return 0;
                        statret = -1;
                }
                if (statret < 0 && do_mkdir(dir, 0700) < 0)
                        return 0;
        } else
                do_rmdir(dir);
        *fn = '/';

        return 1;
}

/** We need to supply our own strcmp function for file list comparisons
   to ensure that signed/unsigned usage is consistent between machines. */
int u_strcmp(const char *cs1, const char *cs2)
{
        const uchar *s1 = (const uchar *)cs1;
        const uchar *s2 = (const uchar *)cs2;

        while (*s1 && *s2 && (*s1 == *s2)) {
                s1++; s2++;
        }

        return (int)*s1 - (int)*s2;
}



/**
 * Determine if a symlink points outside the current directory tree.
 * This is considered "unsafe" because e.g. when mirroring somebody
 * else's machine it might allow them to establish a symlink to
 * /etc/passwd, and then read it through a web server.
 *
 * Null symlinks and absolute symlinks are always unsafe.
 *
 * Basically here we are concerned with symlinks whose target contains
 * "..", because this might cause us to walk back up out of the
 * transferred directory.  We are not allowed to go back up and
 * reenter.
 *
 * @param dest Target of the symlink in question.
 *
 * @param src Top source directory currently applicable.  Basically this
 * is the first parameter to rsync in a simple invocation, but it's
 * modified by flist.c in slightly complex ways.
 *
 * @retval True if unsafe
 * @retval False is unsafe
 *
 * @sa t_unsafe.c
 **/
int unsafe_symlink(const char *dest, const char *src)
{
        const char *name, *slash;
        int depth = 0;

        /* all absolute and null symlinks are unsafe */
        if (!dest || !*dest || *dest == '/')
                return 1;

        /* find out what our safety margin is */
        for (name = src; (slash = strchr(name, '/')) != 0; name = slash+1) {
                if (strncmp(name, "../", 3) == 0) {
                        depth = 0;
                } else if (strncmp(name, "./", 2) == 0) {
                        /* nothing */
                } else {
                        depth++;
                }
        }
        if (strcmp(name, "..") == 0)
                depth = 0;

        for (name = dest; (slash = strchr(name, '/')) != 0; name = slash+1) {
                if (strncmp(name, "../", 3) == 0) {
                        /* if at any point we go outside the current directory
                           then stop - it is unsafe */
                        if (--depth < 0)
                                return 1;
                } else if (strncmp(name, "./", 2) == 0) {
                        /* nothing */
                } else {
                        depth++;
                }
        }
        if (strcmp(name, "..") == 0)
                depth--;

        return (depth < 0);
}


/**
 * Return the date and time as a string
 **/
char *timestring(time_t t)
{
        static char TimeBuf[200];
        struct tm *tm = localtime(&t);

#ifdef HAVE_STRFTIME
        strftime(TimeBuf, sizeof TimeBuf - 1, "%Y/%m/%d %H:%M:%S", tm);
#else
        strlcpy(TimeBuf, asctime(tm), sizeof TimeBuf);
#endif

        if (TimeBuf[strlen(TimeBuf)-1] == '\n') {
                TimeBuf[strlen(TimeBuf)-1] = 0;
        }

        return(TimeBuf);
}


/**
 * Sleep for a specified number of milliseconds.
 *
 * Always returns TRUE.  (In the future it might return FALSE if
 * interrupted.)
 **/
int msleep(int t)
{
        int tdiff = 0;
        struct timeval tval, t1, t2;

        gettimeofday(&t1, NULL);

        while (tdiff < t) {
                tval.tv_sec = (t-tdiff)/1000;
                tval.tv_usec = 1000*((t-tdiff)%1000);

                errno = 0;
                select(0,NULL,NULL, NULL, &tval);

                gettimeofday(&t2, NULL);
                tdiff = (t2.tv_sec - t1.tv_sec)*1000 +
                        (t2.tv_usec - t1.tv_usec)/1000;
        }

        return True;
}


/**
 * Determine if two file modification times are equivalent (either
 * exact or in the modification timestamp window established by
 * --modify-window).
 *
 * @retval 0 if the times should be treated as the same
 *
 * @retval +1 if the first is later
 *
 * @retval -1 if the 2nd is later
 **/
int cmp_modtime(time_t file1, time_t file2)
{
        if (file2 > file1) {
                if (file2 - file1 <= modify_window)
                        return 0;
                return -1;
        }
        if (file1 - file2 <= modify_window)
                return 0;
        return 1;
}


#ifdef __INSURE__XX
#include <dlfcn.h>

/**
   This routine is a trick to immediately catch errors when debugging
   with insure. A xterm with a gdb is popped up when insure catches
   a error. It is Linux specific.
**/
int _Insure_trap_error(int a1, int a2, int a3, int a4, int a5, int a6)
{
        static int (*fn)();
        int ret;
        char *cmd;

        asprintf(&cmd, "/usr/X11R6/bin/xterm -display :0 -T Panic -n Panic -e /bin/sh -c 'cat /tmp/ierrs.*.%d ; gdb /proc/%d/exe %d'",
                getpid(), getpid(), getpid());

        if (!fn) {
                static void *h;
                h = dlopen("/usr/local/parasoft/insure++lite/lib.linux2/libinsure.so", RTLD_LAZY);
                fn = dlsym(h, "_Insure_trap_error");
        }

        ret = fn(a1, a2, a3, a4, a5, a6);

        system(cmd);

        free(cmd);

        return ret;
}
#endif


#define MALLOC_MAX 0x40000000

void *_new_array(unsigned int size, unsigned long num)
{
        if (num >= MALLOC_MAX/size)
                return NULL;
        return malloc(size * num);
}

void *_realloc_array(void *ptr, unsigned int size, unsigned long num)
{
        if (num >= MALLOC_MAX/size)
                return NULL;
        /* No realloc should need this, but just in case... */
        if (!ptr)
                return malloc(size * num);
        return realloc(ptr, size * num);
}

/* Take a filename and filename length and return the most significant
 * filename suffix we can find.  This ignores suffixes such as "~",
 * ".bak", ".orig", ".~1~", etc. */
const char *find_filename_suffix(const char *fn, int fn_len, int *len_ptr)
{
        const char *suf, *s;
        BOOL had_tilde;
        int s_len;

        /* One or more dots at the start aren't a suffix. */
        while (fn_len && *fn == '.') fn++, fn_len--;

        /* Ignore the ~ in a "foo~" filename. */
        if (fn_len > 1 && fn[fn_len-1] == '~')
                fn_len--, had_tilde = True;
        else
                had_tilde = False;

        /* Assume we don't find an suffix. */
        suf = "";
        *len_ptr = 0;

        /* Find the last significant suffix. */
        for (s = fn + fn_len; fn_len > 1; ) {
                while (*--s != '.' && s != fn) {}
                if (s == fn)
                        break;
                s_len = fn_len - (s - fn);
                fn_len = s - fn;
                if (s_len == 4) {
                        if (strcmp(s+1, "bak") == 0
                         || strcmp(s+1, "old") == 0)
                                continue;
                } else if (s_len == 5) {
                        if (strcmp(s+1, "orig") == 0)
                                continue;
                } else if (s_len > 2 && had_tilde
                    && s[1] == '~' && isdigit(*(uchar*)(s+2)))
                        continue;
                *len_ptr = s_len;
                suf = s;
                if (s_len == 1)
                        break;
                /* Determine if the suffix is all digits. */
                for (s++, s_len--; s_len > 0; s++, s_len--) {
                        if (!isdigit(*(uchar*)s))
                                return suf;
                }
                /* An all-digit suffix may not be that signficant. */
                s = suf;
        }

        return suf;
}

/* This is an implementation of the Levenshtein distance algorithm.  It
 * was implemented to avoid needing a two-dimensional matrix (to save
 * memory).  It was also tweaked to try to factor in the ASCII distance
 * between changed characters as a minor distance quantity.  The normal
 * Levenshtein units of distance (each signifying a single change between
 * the two strings) are defined as a "UNIT". */

#define UNIT (1 << 16)

uint32 fuzzy_distance(const char *s1, int len1, const char *s2, int len2)
{
        uint32 a[MAXPATHLEN], diag, above, left, diag_inc, above_inc, left_inc;
        int32 cost;
        int i1, i2;

        if (!len1 || !len2) {
                if (!len1) {
                        s1 = s2;
                        len1 = len2;
                }
                for (i1 = 0, cost = 0; i1 < len1; i1++)
                        cost += s1[i1];
                return (int32)len1 * UNIT + cost;
        }

        for (i2 = 0; i2 < len2; i2++)
                a[i2] = (i2+1) * UNIT;

        for (i1 = 0; i1 < len1; i1++) {
                diag = i1 * UNIT;
                above = (i1+1) * UNIT;
                for (i2 = 0; i2 < len2; i2++) {
                        left = a[i2];
                        if ((cost = *((uchar*)s1+i1) - *((uchar*)s2+i2)) != 0) {
                                if (cost < 0)
                                        cost = UNIT - cost;
                                else
                                        cost = UNIT + cost;
                        }
                        diag_inc = diag + cost;
                        left_inc = left + UNIT + *((uchar*)s1+i1);
                        above_inc = above + UNIT + *((uchar*)s2+i2);
                        a[i2] = above = left < above
                              ? (left_inc < diag_inc ? left_inc : diag_inc)
                              : (above_inc < diag_inc ? above_inc : diag_inc);
                        diag = left;
                }
        }

        return a[len2-1];
}