usr/src/bin/cp/utils.c

#include <stdio.h>
#include <fts.h>
#include <stdlib.h>


void
copy_file(fs, dne)
        struct stat *fs;
        int dne;
{
        static char buf[MAXBSIZE];
        register int from_fd, to_fd, rcount, wcount;
        struct stat to_stat;
        char *p;

        if ((from_fd = open(from.p_path, O_RDONLY, 0)) == -1) {
                err("%s: %s", from.p_path, strerror(errno));
                return;
        }

        /*
         * If the file exists and we're interactive, verify with the user.
         * If the file DNE, set the mode to be the from file, minus setuid
         * bits, modified by the umask; arguably wrong, but it makes copying
         * executables work right and it's been that way forever.  (The
         * other choice is 666 or'ed with the execute bits on the from file
         * modified by the umask.)
         */
        if (!dne) {
                if (iflag) {
                        int checkch, ch;

                        (void)fprintf(stderr, "overwrite %s? ", to.p_path);
                        checkch = ch = getchar();
                        while (ch != '\n' && ch != EOF)
                                ch = getchar();
                        if (checkch != 'y') {
                                (void)close(from_fd);
                                return;
                        }
                }
                to_fd = open(to.p_path, O_WRONLY|O_TRUNC, 0);
        } else
                to_fd = open(to.p_path, O_WRONLY|O_CREAT|O_TRUNC,
                    fs->st_mode & ~(S_ISUID|S_ISGID));

        if (to_fd == -1) {
                err("%s: %s", to.p_path, strerror(errno));
                (void)close(from_fd);
                return;
        }

        /*
         * Mmap and write if less than 8M (the limit is so we don't totally
         * trash memory on big files.  This is really a minor hack, but it
         * wins some CPU back.
         */
        if (fs->st_size <= 8 * 1048576) {
                if ((p = mmap(NULL, fs->st_size, PROT_READ,
                    MAP_FILE, from_fd, (off_t)0)) == (char *)-1)
                        err("%s: %s", from.p_path, strerror(errno));
                if (write(to_fd, p, fs->st_size) != fs->st_size)
                        err("%s: %s", to.p_path, strerror(errno));
        } else {
                while ((rcount = read(from_fd, buf, MAXBSIZE)) > 0) {
                        wcount = write(to_fd, buf, rcount);
                        if (rcount != wcount || wcount == -1) {
                                err("%s: %s", to.p_path, strerror(errno));
                                break;
                        }
                }
                if (rcount < 0)
                        err("%s: %s", from.p_path, strerror(errno));
        }
        if (pflag)
                setfile(fs, to_fd);
        /*
         * If the source was setuid or setgid, lose the bits unless the
         * copy is owned by the same user and group.
         */
        else if (fs->st_mode & (S_ISUID|S_ISGID) && fs->st_uid == myuid)
                if (fstat(to_fd, &to_stat))
                        err("%s: %s", to.p_path, strerror(errno));
#define RETAINBITS      (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO)
                else if (fs->st_gid == to_stat.st_gid && fchmod(to_fd,
                    fs->st_mode & RETAINBITS & ~myumask))
                        err("%s: %s", to.p_path, strerror(errno));
        (void)close(from_fd);
        if (close(to_fd))
                err("%s: %s", to.p_path, strerror(errno));
}

void
copy_dir()
{
        struct stat from_stat;
        struct dirent *dp, **dir_list;
        register int dir_cnt, i;
        char *old_from, *old_to;

        register FTS *ftsp;
        register FTSENT *p;

        dir_cnt = scandir(from.p_path, &dir_list, NULL, NULL);
        if (dir_cnt == -1) {
                (void)fprintf(stderr, "%s: can't read directory %s.\n",
                    progname, from.p_path);
                exit_val = 1;
        }

        /*
         * Instead of handling directory entries in the order they appear
         * on disk, do non-directory files before directory files.
         * There are two reasons to do directories last.  The first is
         * efficiency.  Files tend to be in the same cylinder group as
         * their parent, whereas directories tend not to be.  Copying files
         * all at once reduces seeking.  Second, deeply nested tree's
         * could use up all the file descriptors if we didn't close one
         * directory before recursivly starting on the next.
         */
        /* copy files */
        for (i = 0; i < dir_cnt; ++i) {
                dp = dir_list[i];
                if (dp->d_namlen <= 2 && dp->d_name[0] == '.'
                    && (dp->d_name[1] == NULL || dp->d_name[1] == '.'))
                        goto done;
                if (!(old_from =
                    path_append(&from, dp->d_name, (int)dp->d_namlen)))
                        goto done;

                if (statfcn(from.p_path, &from_stat) < 0) {
                        err("%s: %s", dp->d_name, strerror(errno));
                        path_restore(&from, old_from);
                        goto done;
                }
                if (S_ISDIR(from_stat.st_mode)) {
                        path_restore(&from, old_from);
                        continue;
                }
                if (old_to = path_append(&to, dp->d_name, (int)dp->d_namlen)) {
                        copy();
                        path_restore(&to, old_to);
                }
                path_restore(&from, old_from);
done:           dir_list[i] = NULL;
                free(dp);
        }

        /* copy directories */
        for (i = 0; i < dir_cnt; ++i) {
                dp = dir_list[i];
                if (!dp)
                        continue;
                if (!(old_from =
                    path_append(&from, dp->d_name, (int)dp->d_namlen))) {
                        free(dp);
                        continue;
                }
                if (!(old_to =
                    path_append(&to, dp->d_name, (int)dp->d_namlen))) {
                        free(dp);
                        path_restore(&from, old_from);
                        continue;
                }
                copy();
                free(dp);
                path_restore(&from, old_from);
                path_restore(&to, old_to);
        }
        free(dir_list);
}

void
copy_link(exists)
        int exists;
{
        int len;
        char link[MAXPATHLEN];

        if ((len = readlink(from.p_path, link, sizeof(link))) == -1) {
                err("readlink: %s: %s", from.p_path, strerror(errno));
                return;
        }
        link[len] = '\0';
        if (exists && unlink(to.p_path)) {
                err("unlink: %s: %s", to.p_path, strerror(errno));
                return;
        }
        if (symlink(link, to.p_path)) {
                err("symlink: %s: %s", link, strerror(errno));
                return;
        }
}

void
copy_fifo(from_stat, exists)
        struct stat *from_stat;
        int exists;
{
        if (exists && unlink(to.p_path)) {
                err("unlink: %s: %s", to.p_path, strerror(errno));
                return;
        }
        if (mkfifo(to.p_path, from_stat->st_mode)) {
                err("mkfifo: %s: %s", to.p_path, strerror(errno));
                return;
        }
        if (pflag)
                setfile(from_stat, 0);
}

void
copy_special(from_stat, exists)
        struct stat *from_stat;
        int exists;
{
        if (exists && unlink(to.p_path)) {
                err("unlink: %s: %s", to.p_path, strerror(errno));
                return;
        }
        if (mknod(to.p_path, from_stat->st_mode,  from_stat->st_rdev)) {
                err("mknod: %s: %s", to.p_path, strerror(errno));
                return;
        }
        if (pflag)
                setfile(from_stat, 0);
}


void
setfile(fs, fd)
        register struct stat *fs;
        int fd;
{
        static struct timeval tv[2];

        fs->st_mode &= S_ISUID|S_ISGID|S_IRWXU|S_IRWXG|S_IRWXO;

        tv[0].tv_sec = fs->st_atime;
        tv[1].tv_sec = fs->st_mtime;
        if (utimes(to.p_path, tv))
                err("utimes: %s: %s", to.p_path, strerror(errno));
        /*
         * Changing the ownership probably won't succeed, unless we're root
         * or POSIX_CHOWN_RESTRICTED is not set.  Set uid/gid before setting
         * the mode; current BSD behavior is to remove all setuid bits on
         * chown.  If chown fails, lose setuid/setgid bits.
         */
        if (fd ? fchown(fd, fs->st_uid, fs->st_gid) :
            chown(to.p_path, fs->st_uid, fs->st_gid)) {
                if (errno != EPERM)
                        err("chown: %s: %s", to.p_path, strerror(errno));
                fs->st_mode &= ~(S_ISUID|S_ISGID);
        }
        if (fd ? fchmod(fd, fs->st_mode) : chmod(to.p_path, fs->st_mode))
                err("chown: %s: %s", to.p_path, strerror(errno));
}

void
usage()
{
        (void)fprintf(stderr,
"usage: cp [-Rfhip] src target;\n       cp [-Rfhip] src1 ... srcN directory\n");
        exit(1);
}

#if __STDC__
#include <stdarg.h>
#else
#include <varargs.h>
#endif

void
#if __STDC__
err(const char *fmt, ...)
#else
err(fmt, va_alist)
        char *fmt;
        va_dcl
#endif
{
        va_list ap;
#if __STDC__
        va_start(ap, fmt);
#else
        va_start(ap);
#endif
        (void)fprintf(stderr, "%s: ", progname);
        (void)vfprintf(stderr, fmt, ap);
        va_end(ap);
        (void)fprintf(stderr, "\n");
        exit_val = 1;
}