diff options
| -rw-r--r-- | shell/hush.c | 109 |
1 files changed, 72 insertions, 37 deletions
diff --git a/shell/hush.c b/shell/hush.c index 0fae809b3..d4101d66f 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -1454,11 +1454,11 @@ static int fcntl_F_DUPFD(int fd, int avoid_fd) return newfd; } -static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC, int avoid_fd) +static int xdup_CLOEXEC_and_close(int fd, int avoid_fd) { int newfd; repeat: - newfd = fcntl(fd, F_DUPFD_maybe_CLOEXEC, avoid_fd + 1); + newfd = fcntl(fd, F_DUPFD_CLOEXEC, avoid_fd + 1); if (newfd < 0) { if (errno == EBUSY) goto repeat; @@ -1469,6 +1469,8 @@ static int xdup_and_close(int fd, int F_DUPFD_maybe_CLOEXEC, int avoid_fd) return fd; xfunc_die(); } + if (F_DUPFD_CLOEXEC == F_DUPFD) /* if old libc (w/o F_DUPFD_CLOEXEC) */ + fcntl(newfd, F_SETFD, FD_CLOEXEC); close(fd); return newfd; } @@ -1507,7 +1509,7 @@ static int save_FILEs_on_redirect(int fd, int avoid_fd) while (fl) { if (fd == fl->fd) { /* We use it only on script files, they are all CLOEXEC */ - fl->fd = xdup_and_close(fd, F_DUPFD_CLOEXEC, avoid_fd); + fl->fd = xdup_CLOEXEC_and_close(fd, avoid_fd); debug_printf_redir("redirect_fd %d: matches a script fd, moving it to %d\n", fd, fl->fd); return 1; } @@ -6711,18 +6713,42 @@ static struct squirrel *add_squirrel(struct squirrel *sq, int fd, int avoid_fd) return append_squirrel(sq, i, fd, moved_to); } +static struct squirrel *add_squirrel_closed(struct squirrel *sq, int fd) +{ + int i; + + i = 0; + if (sq) while (sq[i].orig_fd >= 0) { + /* If we collide with an already moved fd... */ + if (fd == sq[i].orig_fd) { + /* Examples: + * "echo 3>FILE 3>&- 3>FILE" + * "echo 3>&- 3>FILE" + * No need for last redirect to insert + * another "need to close 3" indicator. + */ + debug_printf_redir("redirect_fd %d: already moved or closed\n", fd); + return sq; + } + i++; + } + + debug_printf_redir("redirect_fd %d: previous fd was closed\n", fd); + return append_squirrel(sq, i, fd, -1); +} + /* fd: redirect wants this fd to be used (e.g. 3>file). * Move all conflicting internally used fds, * and remember them so that we can restore them later. */ -static int save_fds_on_redirect(int fd, int avoid_fd, struct squirrel **sqp) +static int save_fd_on_redirect(int fd, int avoid_fd, struct squirrel **sqp) { if (avoid_fd < 9) /* the important case here is that it can be -1 */ avoid_fd = 9; #if ENABLE_HUSH_INTERACTIVE if (fd != 0 && fd == G.interactive_fd) { - G.interactive_fd = xdup_and_close(G.interactive_fd, F_DUPFD_CLOEXEC, avoid_fd); + G.interactive_fd = xdup_CLOEXEC_and_close(G.interactive_fd, avoid_fd); debug_printf_redir("redirect_fd %d: matches interactive_fd, moving it to %d\n", fd, G.interactive_fd); return 1; /* "we closed fd" */ } @@ -6748,7 +6774,6 @@ static int save_fds_on_redirect(int fd, int avoid_fd, struct squirrel **sqp) static void restore_redirects(struct squirrel *sq) { - if (sq) { int i = 0; while (sq[i].orig_fd >= 0) { @@ -6775,13 +6800,15 @@ static void restore_redirects(struct squirrel *sq) * and stderr if they are redirected. */ static int setup_redirects(struct command *prog, struct squirrel **sqp) { - int openfd, mode; struct redir_struct *redir; for (redir = prog->redirects; redir; redir = redir->next) { + int newfd; + int closed; + if (redir->rd_type == REDIRECT_HEREDOC2) { /* "rd_fd<<HERE" case */ - save_fds_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp); + save_fd_on_redirect(redir->rd_fd, /*avoid:*/ 0, sqp); /* for REDIRECT_HEREDOC2, rd_filename holds _contents_ * of the heredoc */ debug_printf_parse("set heredoc '%s'\n", @@ -6793,6 +6820,8 @@ static int setup_redirects(struct command *prog, struct squirrel **sqp) if (redir->rd_dup == REDIRFD_TO_FILE) { /* "rd_fd<*>file" case (<*> is <,>,>>,<>) */ char *p; + int mode; + if (redir->rd_filename == NULL) { /* * Examples: @@ -6804,9 +6833,9 @@ static int setup_redirects(struct command *prog, struct squirrel **sqp) } mode = redir_table[redir->rd_type].mode; p = expand_string_to_string(redir->rd_filename, /*unbackslash:*/ 1); - openfd = open_or_warn(p, mode); + newfd = open_or_warn(p, mode); free(p); - if (openfd < 0) { + if (newfd < 0) { /* Error message from open_or_warn can be lost * if stderr has been redirected, but bash * and ash both lose it as well @@ -6814,40 +6843,46 @@ static int setup_redirects(struct command *prog, struct squirrel **sqp) */ return 1; } - if (openfd == redir->rd_fd && sqp) { + if (newfd == redir->rd_fd && sqp) { /* open() gave us precisely the fd we wanted. * This means that this fd was not busy * (not opened to anywhere). * Remember to close it on restore: */ - struct squirrel *sq = *sqp; - int i = 0; - if (sq) while (sq[i].orig_fd >= 0) - i++; - *sqp = append_squirrel(sq, i, openfd, -1); /* -1 = "it was closed" */ - debug_printf_redir("redir to previously closed fd %d\n", openfd); + *sqp = add_squirrel_closed(*sqp, newfd); + debug_printf_redir("redir to previously closed fd %d\n", newfd); } } else { - /* "rd_fd<*>rd_dup" or "rd_fd<*>-" cases */ - openfd = redir->rd_dup; - } - - if (openfd != redir->rd_fd) { - int closed = save_fds_on_redirect(redir->rd_fd, /*avoid:*/ openfd, sqp); - if (openfd == REDIRFD_CLOSE) { - /* "rd_fd >&-" means "close me" */ - if (!closed) { - /* ^^^ optimization: saving may already - * have closed it. If not... */ - close(redir->rd_fd); - } - } else { - xdup2(openfd, redir->rd_fd); - if (redir->rd_dup == REDIRFD_TO_FILE) - /* "rd_fd > FILE" */ - close(openfd); - /* else: "rd_fd > rd_dup" */ - } + /* "rd_fd>&rd_dup" or "rd_fd>&-" case */ + newfd = redir->rd_dup; + } + + if (newfd == redir->rd_fd) + continue; + + /* if "N>FILE": move newfd to redir->rd_fd */ + /* if "N>&M": dup newfd to redir->rd_fd */ + /* if "N>&-": close redir->rd_fd (newfd is REDIRFD_CLOSE) */ + + closed = save_fd_on_redirect(redir->rd_fd, /*avoid:*/ newfd, sqp); + if (newfd == REDIRFD_CLOSE) { + /* "N>&-" means "close me" */ + if (!closed) { + /* ^^^ optimization: saving may already + * have closed it. If not... */ + close(redir->rd_fd); + } + /* Sometimes we do another close on restore, getting EBADF. + * Consider "echo 3>FILE 3>&-" + * first redirect remembers "need to close 3", + * and second redirect closes 3! Restore code then closes 3 again. + */ + } else { + xdup2(newfd, redir->rd_fd); + if (redir->rd_dup == REDIRFD_TO_FILE) + /* "rd_fd > FILE" */ + close(newfd); + /* else: "rd_fd > rd_dup" */ } } return 0; |