X-Git-Url: https://git.brokenzipper.com/gitweb?a=blobdiff_plain;f=src%2Fextract.c;h=aaea56ed3abcfcfb2bfde356715f6133e22e4fae;hb=649b747913d2b289e904b5f1d222af886acd209c;hp=2730a03ab7129c824e42e316a66652ce6affb056;hpb=4bde4f39d08f000f7e63a832b08a2525c1262f84;p=chaz%2Ftar diff --git a/src/extract.c b/src/extract.c index 2730a03..aaea56e 100644 --- a/src/extract.c +++ b/src/extract.c @@ -375,7 +375,7 @@ mark_after_links (struct delayed_set_stat *head) struct stat st; h->after_links = 1; - if (fstatat (chdir_fd, h->file_name, &st, 0) != 0) + if (deref_stat (h->file_name, &st) != 0) stat_error (h->file_name); else { @@ -478,20 +478,20 @@ repair_delayed_set_stat (char const *dir, /* After a file/link/directory creation has failed, see if it's because some required directory was not present, and if so, - create all required directories. Return non-zero if a directory - was created. */ + create all required directories. Return zero if all the required + directories were created, nonzero (issuing a diagnostic) otherwise. + Set *INTERDIR_MADE if at least one directory was created. */ static int -make_directories (char *file_name) +make_directories (char *file_name, bool *interdir_made) { char *cursor0 = file_name + FILE_SYSTEM_PREFIX_LEN (file_name); char *cursor; /* points into the file name */ - int did_something = 0; /* did we do anything yet? */ - int status; for (cursor = cursor0; *cursor; cursor++) { mode_t mode; mode_t desired_mode; + int status; if (! ISSLASH (*cursor)) continue; @@ -524,51 +524,60 @@ make_directories (char *file_name) desired_mode, AT_SYMLINK_NOFOLLOW); print_for_mkdir (file_name, cursor - file_name, desired_mode); - did_something = 1; - - *cursor = '/'; - continue; + *interdir_made = true; + } + else if (errno == EEXIST) + status = 0; + else + { + /* Check whether the desired file exists. Even when the + file exists, mkdir can fail with some errno value E other + than EEXIST, so long as E describes an error condition + that also applies. */ + int e = errno; + struct stat st; + status = fstatat (chdir_fd, file_name, &st, 0); + if (status) + { + errno = e; + mkdir_error (file_name); + } } *cursor = '/'; - - if (errno == EEXIST) - continue; /* Directory already exists. */ - else if ((errno == ENOSYS /* Automounted dirs on Solaris return - this. Reported by Warren Hyde - */ - || ERRNO_IS_EACCES) /* Turbo C mkdir gives a funny errno. */ - && faccessat (chdir_fd, file_name, W_OK, AT_EACCESS) == 0) - continue; - - /* Some other error in the mkdir. We return to the caller. */ - break; + if (status) + return status; } - return did_something; /* tell them to retry if we made one */ + return 0; } +/* Return true if FILE_NAME (with status *STP, if STP) is not a + directory, and has a time stamp newer than (or equal to) that of + TAR_STAT. */ static bool -file_newer_p (const char *file_name, struct tar_stat_info *tar_stat) +file_newer_p (const char *file_name, struct stat const *stp, + struct tar_stat_info *tar_stat) { struct stat st; - if (fstatat (chdir_fd, file_name, &st, 0)) + if (!stp) { - if (errno != ENOENT) + if (deref_stat (file_name, &st) != 0) { - stat_warn (file_name); - /* Be on the safe side: if the file does exist assume it is newer */ - return true; + if (errno != ENOENT) + { + stat_warn (file_name); + /* Be safer: if the file exists, assume it is newer. */ + return true; + } + return false; } - return false; - } - if (!S_ISDIR (st.st_mode) - && tar_timespec_cmp (tar_stat->mtime, get_stat_mtime (&st)) <= 0) - { - return true; + stp = &st; } - return false; + + return (! S_ISDIR (stp->st_mode) + && tar_timespec_cmp (tar_stat->mtime, get_stat_mtime (stp)) <= 0); } #define RECOVER_NO 0 @@ -580,18 +589,51 @@ file_newer_p (const char *file_name, struct tar_stat_info *tar_stat) Return RECOVER_OK if we somewhat increased our chances at a successful extraction, RECOVER_NO if there are no chances, and RECOVER_SKIP if the caller should skip extraction of that member. The value of errno is - properly restored on returning RECOVER_NO. */ + properly restored on returning RECOVER_NO. + + If REGULAR, the caller was trying to extract onto a regular file. + + Set *INTERDIR_MADE if an intermediate directory is made as part of + the recovery process. */ static int -maybe_recoverable (char *file_name, bool *interdir_made) +maybe_recoverable (char *file_name, bool regular, bool *interdir_made) { int e = errno; + struct stat st; + struct stat const *stp = 0; if (*interdir_made) return RECOVER_NO; - switch (errno) + switch (e) { + case ELOOP: + + /* With open ("symlink", O_NOFOLLOW|...), POSIX says errno == ELOOP, + but some operating systems do not conform to the standard. */ +#ifdef EFTYPE + /* NetBSD uses errno == EFTYPE; see . */ + case EFTYPE: +#endif + /* FreeBSD 8.1 uses errno == EMLINK. */ + case EMLINK: + /* Tru64 5.1B uses errno == ENOTSUP. */ + case ENOTSUP: + + if (! regular + || old_files_option != OVERWRITE_OLD_FILES || dereference_option) + break; + if (strchr (file_name, '/')) + { + if (deref_stat (file_name, &st) != 0) + break; + stp = &st; + } + + /* The caller tried to open a symbolic link with O_NOFOLLOW. + Fall through, treating it as an already-existing file. */ + case EEXIST: /* Remove an old file, if the options allow this. */ @@ -601,21 +643,16 @@ maybe_recoverable (char *file_name, bool *interdir_made) return RECOVER_SKIP; case KEEP_NEWER_FILES: - if (file_newer_p (file_name, ¤t_stat_info)) - { - errno = e; - return RECOVER_NO; - } + if (file_newer_p (file_name, stp, ¤t_stat_info)) + break; /* FALL THROUGH */ case DEFAULT_OLD_FILES: case NO_OVERWRITE_DIR_OLD_FILES: case OVERWRITE_OLD_FILES: - { - int r = remove_any_file (file_name, ORDINARY_REMOVE_OPTION); - errno = EEXIST; - return r > 0 ? RECOVER_OK : RECOVER_NO; - } + if (0 < remove_any_file (file_name, ORDINARY_REMOVE_OPTION)) + return RECOVER_OK; + break; case UNLINK_FIRST_OLD_FILES: break; @@ -623,19 +660,17 @@ maybe_recoverable (char *file_name, bool *interdir_made) case ENOENT: /* Attempt creating missing intermediate directories. */ - if (! make_directories (file_name)) - { - errno = ENOENT; - return RECOVER_NO; - } - *interdir_made = true; - return RECOVER_OK; + if (make_directories (file_name, interdir_made) == 0 && *interdir_made) + return RECOVER_OK; + break; default: /* Just say we can't do anything about it... */ - - return RECOVER_NO; + break; } + + errno = e; + return RECOVER_NO; } /* Fix the statuses of all directories whose statuses need fixing, and @@ -754,7 +789,7 @@ extract_dir (char *file_name, int typeflag) for (;;) { - status = mkdir (file_name, mode); + status = mkdirat (chdir_fd, file_name, mode); if (status == 0) { current_mode = mode & ~ current_umask; @@ -769,7 +804,7 @@ extract_dir (char *file_name, int typeflag) || old_files_option == OVERWRITE_OLD_FILES)) { struct stat st; - if (fstatat (chdir_fd, file_name, &st, 0) == 0) + if (deref_stat (file_name, &st) == 0) { current_mode = st.st_mode; current_mode_mask = ALL_MODE_BITS; @@ -787,7 +822,7 @@ extract_dir (char *file_name, int typeflag) errno = EEXIST; } - switch (maybe_recoverable (file_name, &interdir_made)) + switch (maybe_recoverable (file_name, false, &interdir_made)) { case RECOVER_OK: continue; @@ -823,8 +858,11 @@ open_output_file (char const *file_name, int typeflag, mode_t mode, { int fd; bool overwriting_old_files = old_files_option == OVERWRITE_OLD_FILES; - int openflag = (O_WRONLY | O_BINARY | O_CREAT - | (overwriting_old_files ? O_TRUNC : O_EXCL)); + int openflag = (O_WRONLY | O_BINARY | O_CLOEXEC | O_NOCTTY | O_NONBLOCK + | O_CREAT + | (overwriting_old_files + ? O_TRUNC | (dereference_option ? 0 : O_NOFOLLOW) + : O_EXCL)); if (typeflag == CONTTYPE) { @@ -838,6 +876,20 @@ open_output_file (char const *file_name, int typeflag, mode_t mode, } } + /* If O_NOFOLLOW is needed but does not work, check for a symlink + separately. There's a race condition, but that cannot be avoided + on hosts lacking O_NOFOLLOW. */ + if (! O_NOFOLLOW && overwriting_old_files && ! dereference_option) + { + struct stat st; + if (fstatat (chdir_fd, file_name, &st, AT_SYMLINK_NOFOLLOW) == 0 + && S_ISLNK (st.st_mode)) + { + errno = ELOOP; + return -1; + } + } + fd = openat (chdir_fd, file_name, openflag, mode); if (0 <= fd) { @@ -898,21 +950,19 @@ extract_file (char *file_name, int typeflag) } else { - int recover = RECOVER_NO; - do - fd = open_output_file (file_name, typeflag, mode, - ¤t_mode, ¤t_mode_mask); - while (fd < 0 - && (recover = maybe_recoverable (file_name, &interdir_made)) - == RECOVER_OK); - - if (fd < 0) + while ((fd = open_output_file (file_name, typeflag, mode, + ¤t_mode, ¤t_mode_mask)) + < 0) { - skip_member (); - if (recover == RECOVER_SKIP) - return 0; - open_error (file_name); - return 1; + int recover = maybe_recoverable (file_name, true, &interdir_made); + if (recover != RECOVER_OK) + { + skip_member (); + if (recover == RECOVER_SKIP) + return 0; + open_error (file_name); + return 1; + } } } @@ -994,7 +1044,7 @@ create_placeholder_file (char *file_name, bool is_symlink, bool *interdir_made) while ((fd = openat (chdir_fd, file_name, O_WRONLY | O_CREAT | O_EXCL, 0)) < 0) { - switch (maybe_recoverable (file_name, interdir_made)) + switch (maybe_recoverable (file_name, false, interdir_made)) { case RECOVER_OK: continue; @@ -1106,7 +1156,8 @@ extract_link (char *file_name, int typeflag) errno = e; } - while ((rc = maybe_recoverable (file_name, &interdir_made)) == RECOVER_OK); + while ((rc = maybe_recoverable (file_name, false, &interdir_made)) + == RECOVER_OK); if (rc == RECOVER_SKIP) return 0; @@ -1130,7 +1181,7 @@ extract_symlink (char *file_name, int typeflag) return create_placeholder_file (file_name, true, &interdir_made); while (symlinkat (current_stat_info.link_name, chdir_fd, file_name) != 0) - switch (maybe_recoverable (file_name, &interdir_made)) + switch (maybe_recoverable (file_name, false, &interdir_made)) { case RECOVER_OK: continue; @@ -1166,12 +1217,12 @@ static int extract_node (char *file_name, int typeflag) { bool interdir_made = false; - mode_t mode = (current_stat_info.stat.st_mode & MODE_RWX + mode_t mode = (current_stat_info.stat.st_mode & (MODE_RWX | S_IFBLK | S_IFCHR) & ~ (0 < same_owner_option ? S_IRWXG | S_IRWXO : 0)); while (mknodat (chdir_fd, file_name, mode, current_stat_info.stat.st_rdev) != 0) - switch (maybe_recoverable (file_name, &interdir_made)) + switch (maybe_recoverable (file_name, false, &interdir_made)) { case RECOVER_OK: continue; @@ -1200,7 +1251,7 @@ extract_fifo (char *file_name, int typeflag) & ~ (0 < same_owner_option ? S_IRWXG | S_IRWXO : 0)); while (mkfifoat (chdir_fd, file_name, mode) != 0) - switch (maybe_recoverable (file_name, &interdir_made)) + switch (maybe_recoverable (file_name, false, &interdir_made)) { case RECOVER_OK: continue; @@ -1348,7 +1399,7 @@ prepare_to_extract (char const *file_name, int typeflag, tar_extractor_t *fun) break; case KEEP_NEWER_FILES: - if (file_newer_p (file_name, ¤t_stat_info)) + if (file_newer_p (file_name, 0, ¤t_stat_info)) { WARNOPT (WARN_IGNORE_NEWER, (0, 0, _("Current %s is newer or same age"), @@ -1520,11 +1571,12 @@ rename_directory (char *src, char *dst) if (renameat (chdir_fd, src, chdir_fd, dst) != 0) { int e = errno; + bool interdir_made; switch (e) { case ENOENT: - if (make_directories (dst)) + if (make_directories (dst, &interdir_made) == 0) { if (renameat (chdir_fd, src, chdir_fd, dst) == 0) return true;