From 21806562ca6350c78a14a89c22f985900ce96ade Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Fri, 1 Nov 2019 14:16:07 +0100 Subject: hush: restore redirected stdin function old new delta restore_redirects 52 95 +43 save_fd_on_redirect 243 253 +10 hfopen 90 99 +9 fgetc_interactive 259 261 +2 builtin_type 117 115 -2 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 4/1 up/down: 64/-2) Total: 62 bytes Signed-off-by: Denys Vlasenko --- shell/hush.c | 29 ++++++++++++++++++++++------- 1 file changed, 22 insertions(+), 7 deletions(-) (limited to 'shell/hush.c') diff --git a/shell/hush.c b/shell/hush.c index 96a935875..25e5fb906 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -573,7 +573,6 @@ typedef struct HFILE { char *cur; char *end; struct HFILE *next_hfile; - int is_stdin; int fd; char buf[1024]; } HFILE; @@ -973,6 +972,7 @@ struct globals { unsigned execute_lineno; #endif HFILE *HFILE_list; + HFILE *HFILE_stdin; /* Which signals have non-DFL handler (even with no traps set)? * Set at the start to: * (SIGQUIT + maybe SPECIAL_INTERACTIVE_SIGS + maybe SPECIAL_JOBSTOP_SIGS) @@ -1603,7 +1603,8 @@ static HFILE *hfopen(const char *name) } fp = xmalloc(sizeof(*fp)); - fp->is_stdin = (name == NULL); + if (name == NULL) + G.HFILE_stdin = fp; fp->fd = fd; fp->cur = fp->end = fp->buf; fp->next_hfile = G.HFILE_list; @@ -2666,7 +2667,7 @@ static int fgetc_interactive(struct in_str *i) { int ch; /* If it's interactive stdin, get new line. */ - if (G_interactive_fd && i->file->is_stdin) { + if (G_interactive_fd && i->file == G.HFILE_stdin) { /* Returns first char (or EOF), the rest is in i->p[] */ ch = get_user_input(i); G.promptmode = 1; /* PS2 */ @@ -7605,7 +7606,9 @@ static int save_fd_on_redirect(int fd, int avoid_fd, struct squirrel **sqp) avoid_fd = 9; #if ENABLE_HUSH_INTERACTIVE - if (fd == G_interactive_fd) { + if (fd != 0 /* don't trigger for G_interactive_fd == 0 (that's "not interactive" flag) */ + && fd == G_interactive_fd + ) { /* Testcase: "ls -l /proc/$$/fd 255>&-" should work */ 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); @@ -7619,7 +7622,7 @@ static int save_fd_on_redirect(int fd, int avoid_fd, struct squirrel **sqp) /* No need to move script fds. * For NOMMU case, it's actively wrong: we'd change ->fd * fields in memory for the parent, but parent's fds - * aren't be moved, it would use wrong fd! + * aren't moved, it would use wrong fd! * Reproducer: "cmd 3>FILE" in script. * If we would call move_HFILEs_on_redirect(), child would: * fcntl64(3, F_DUPFD_CLOEXEC, 10) = 10 @@ -7683,6 +7686,20 @@ static void restore_redirects(struct squirrel *sq) } free(sq); } + if (G.HFILE_stdin + && G.HFILE_stdin->fd != STDIN_FILENO + ) { + /* Testcase: interactive "read r fd to e.g. 10, + * and it is not restored above (we do not restore script fds + * after redirects, we just use new, "moved" fds). + * However for stdin, get_user_input() -> read_line_input(), + * and read builtin, depend on fd == STDIN_FILENO. + */ + debug_printf_redir("restoring %d to stdin\n", G.HFILE_stdin->fd); + xmove_fd(G.HFILE_stdin->fd, STDIN_FILENO); + G.HFILE_stdin->fd = STDIN_FILENO; + } /* If moved, G_interactive_fd stays on new fd, not restoring it */ } @@ -10214,8 +10231,6 @@ int hush_main(int argc, char **argv) G_saved_tty_pgrp = 0; } } -// TODO: track & disallow any attempts of user -// to (inadvertently) close/redirect G_interactive_fd } debug_printf("interactive_fd:%d\n", G_interactive_fd); if (G_interactive_fd) { -- cgit v1.2.3