The close_all() function was missing its "void" prototype.

[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;

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;

#if 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\" ", *cmd);
                } else {
                        rprintf(FINFO, "%s ", *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)
{
        extern int dry_run;
        if (dry_run)
                return 0;

        if (verbose > 2) {
                rprintf(FINFO, "set modtime of %s to (%ld) %s",
                        fname, (long) modtime,
                        asctime(localtime(&modtime)));
        }
        
        {
#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,'/'))) {
                *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.
 */
static 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)  {
#ifdef EINTR
                        if (errno == EINTR)
                                continue;
#endif
                        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;
 
#ifdef EINTR
        do {
                n_chars = read(desc, ptr, len);
        } while (n_chars < 0 && errno == EINTR);
#else
        n_chars = read(desc, ptr, len);
#endif
 
        return n_chars;
}


/** Copy a file.
 *
 * This is used in conjunction with the --temp-dir option */
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) {
                rprintf(FERROR,"open %s: %s\n",
                        source,strerror(errno));
                return -1;
        }

        if (robust_unlink(dest) && errno != ENOENT) {
                rprintf(FERROR,"unlink %s: %s\n",
                        dest,strerror(errno));
                return -1;
        }

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

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

        close(ifd);
        close(ofd);

        if (len < 0) {
                rprintf(FERROR,"read %s: %s\n",
                        source,strerror(errno));
                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;

        strlcpy(path, fname, MAXPATHLEN);

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

        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",
                                            fname, path);

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

int robust_rename(char *from, char *to)
{
#ifndef ETXTBSY
        return do_rename(from, to);
#else
        int rc = do_rename(from, to);
        if ((rc == 0) || (errno != ETXTBSY))
                return rc;
        if (robust_unlink(to) != 0)
                return -1;
        return do_rename(from, to);
#endif
}


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 void glob_expand_one(char *s, char **argv, int *argc, int maxargs)
{
#if !(defined(HAVE_GLOB) && defined(HAVE_GLOB_H))
        if (!*s) s = ".";
        argv[*argc] = strdup(s);
        (*argc)++;
        return;
#else
        extern int sanitize_paths;
        glob_t globbuf;
        int i;

        if (!*s) s = ".";

        argv[*argc] = strdup(s);
        if (sanitize_paths) {
                sanitize_path(argv[*argc], NULL);
        }

        memset(&globbuf, 0, sizeof(globbuf));
        glob(argv[*argc], 0, NULL, &globbuf);
        if (globbuf.gl_pathc == 0) {
                (*argc)++;
                globfree(&globbuf);
                return;
        }
        for (i=0; i<(maxargs - (*argc)) && i < (int) globbuf.gl_pathc;i++) {
                if (i == 0) free(argv[*argc]);
                argv[(*argc) + i] = strdup(globbuf.gl_pathv[i]);
                if (!argv[(*argc) + i]) out_of_memory("glob_expand");
        }
        globfree(&globbuf);
        (*argc) += i;
#endif
}

void glob_expand(char *base1, char **argv, int *argc, int maxargs)
{
        char *s = argv[*argc];
        char *p, *q;
        char *base = base1;

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

        if (strncmp(s, base, strlen(base)) == 0) {
                s += strlen(base);
        }

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

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

        q = s;
        while ((p = strstr(q,base)) && ((*argc) < maxargs)) {
                /* split it at this point */
                *p = 0;
                glob_expand_one(q, argv, argc, maxargs);
                q = p+strlen(base);
        }

        if (*q && (*argc < maxargs)) glob_expand_one(q, argv, argc, maxargs);

        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++;
        }
}

void *Realloc(void *p, int size)
{
        if (!p) return (void *)malloc(size);
        return (void *)realloc(p, size);
}


void clean_fname(char *name)
{
        char *p;
        int l;
        int modified = 1;

        if (!name) return;

        while (modified) {
                modified = 0;

                if ((p=strstr(name,"/./"))) {
                        modified = 1;
                        while (*p) {
                                p[0] = p[2];
                                p++;
                        }
                }

                if ((p=strstr(name,"//"))) {
                        modified = 1;
                        while (*p) {
                                p[0] = p[1];
                                p++;
                        }
                }

                if (strncmp(p=name,"./",2) == 0) {      
                        modified = 1;
                        do {
                                p[0] = p[2];
                        } while (*p++);
                }

                l = strlen(p=name);
                if (l > 1 && p[l-1] == '/') {
                        modified = 1;
                        p[l-1] = 0;
                }
        }
}

/**
 * Make path appear as if a chroot had occurred:
 *
 * @li 1. remove leading "/" (or replace with "." if at end)
 *
 * @li 2. remove leading ".." components (except those allowed by @p reldir)
 *
 * @li 3. delete any other "<dir>/.." (recursively)
 *
 * Can only shrink paths, so sanitizes in place.
 *
 * While we're at it, remove double slashes and "." components like
 *   clean_fname() does, but DON'T remove a trailing slash because that
 *   is sometimes significant on command line arguments.
 *
 * If @p reldir is non-null, it is a sanitized directory that the path will be
 *    relative to, so allow as many ".." at the beginning of the path as
 *    there are components in reldir.  This is used for symbolic link targets.
 *    If reldir is non-null and the path began with "/", to be completely like
 *    a chroot we should add in depth levels of ".." at the beginning of the
 *    path, but that would blow the assumption that the path doesn't grow and
 *    it is not likely to end up being a valid symlink anyway, so just do
 *    the normal removal of the leading "/" instead.
 *
 * Contributed by Dave Dykstra <dwd@bell-labs.com>
 */
void sanitize_path(char *p, char *reldir)
{
        char *start, *sanp;
        int depth = 0;
        int allowdotdot = 0;

        if (reldir) {
                depth++;
                while (*reldir) {
                        if (*reldir++ == '/') {
                                depth++;
                        }
                }
        }
        start = p;
        sanp = p;
        while (*p == '/') {
                /* remove leading slashes */
                p++;
        }
        while (*p != '\0') {
                /* 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 */
                        while (*++p == '/') {
                                /* skip following slashes */
                                ;
                        }
                        continue;
                }
                allowdotdot = 0;
                if ((*p == '.') && (*(p+1) == '.') &&
                            ((*(p+2) == '/') || (*(p+2) == '\0'))) {
                        /* ".." component followed by slash or end */
                        if ((depth > 0) && (sanp == start)) {
                                /* allow depth levels of .. at the beginning */
                                --depth;
                                allowdotdot = 1;
                        } else {
                                p += 2;
                                if (*p == '/')
                                        p++;
                                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;
                        }
                }
                while (1) {
                        /* copy one component through next slash */
                        *sanp++ = *p++;
                        if ((*p == '\0') || (*(p-1) == '/')) {
                                while (*p == '/') {
                                        /* skip multiple slashes */
                                        p++;
                                }
                                break;
                        }
                }
                if (allowdotdot) {
                        /* move the virtual beginning to leave the .. alone */
                        start = sanp;
                }
        }
        if ((sanp == start) && !allowdotdot) {
                /* ended up with nothing, so put in "." component */
                /*
                 * note that the !allowdotdot doesn't prevent this from
                 *  happening in all allowed ".." situations, but I didn't
                 *  think it was worth putting in an extra variable to ensure
                 *  it since an extra "." won't hurt in those situations.
                 */
                *sanp++ = '.';
        }
        *sanp = '\0';
}


static char curr_dir[MAXPATHLEN];

/**
 * Like chdir() but can be reversed with pop_dir() if @p save is set.
 * It is also much faster as it remembers where we have been.
 **/
char *push_dir(char *dir, int save)
{
        char *ret = curr_dir;
        static int initialised;

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

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

        if (chdir(dir)) return NULL;

        if (save) {
                ret = strdup(curr_dir);
        }

        if (*dir == '/') {
                strlcpy(curr_dir, dir, sizeof(curr_dir));
        } else {
                strlcat(curr_dir,"/", sizeof(curr_dir));
                strlcat(curr_dir,dir, sizeof(curr_dir));
        }

        clean_fname(curr_dir);

        return ret;
}

/** Reverse a push_dir() call */
int pop_dir(char *dir)
{
        int ret;

        ret = chdir(dir);
        if (ret) {
                free(dir);
                return ret;
        }

        strlcpy(curr_dir, dir, sizeof(curr_dir));

        free(dir);

        return 0;
}

/** 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 %T",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);
        gettimeofday(&t2, 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)
{
        extern int modify_window;

        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