diff --git a/lib/util/term.c b/lib/util/term.c index 6545d2647..a7286b59f 100644 --- a/lib/util/term.c +++ b/lib/util/term.c @@ -1,7 +1,7 @@ /* * SPDX-License-Identifier: ISC * - * Copyright (c) 2011-2015, 2017-2020 Todd C. Miller + * Copyright (c) 2011-2015, 2017-2023 Todd C. Miller * * Permission to use, copy, modify, and distribute this software for any * purpose with or without fee is hereby granted, provided that the above @@ -82,12 +82,16 @@ #ifndef ECHOKE # define ECHOKE 0 #endif -#ifndef PENDIN -# define PENDIN 0 -#endif -static struct termios oterm; -static int changed; +/* Termios flags to copy between terminals. */ +#define INPUT_FLAGS (IGNPAR|PARMRK|INPCK|ISTRIP|INLCR|IGNCR|ICRNL|IUCLC|IXON|IXANY|IXOFF|IMAXBEL|IUTF8) +#define OUTPUT_FLAGS (OPOST|OLCUC|ONLCR|OCRNL|ONOCR|ONLRET) +#define CONTROL_FLAGS (CS7|CS8|PARENB|PARODD) +#define LOCAL_FLAGS (ISIG|ICANON|XCASE|ECHO|ECHOE|ECHOK|ECHONL|NOFLSH|TOSTOP|IEXTEN|ECHOCTL|ECHOKE) + +static struct termios orig_term; +static struct termios cur_term; +static bool changed; /* tgetpass() needs to know the erase and kill chars for cbreak mode. */ sudo_dso_public int sudo_term_eof; @@ -129,7 +133,7 @@ tcsetattr_nobg(int fd, int flags, struct termios *tp) sigaction(SIGTTOU, &sa, &osa); do { rc = tcsetattr(fd, flags, tp); - } while (rc != 0 && errno == EINTR && !got_sigttou); + } while (rc == -1 && errno == EINTR && !got_sigttou); sigaction(SIGTTOU, &osa, NULL); debug_return_int(rc); @@ -142,15 +146,75 @@ tcsetattr_nobg(int fd, int flags, struct termios *tp) bool sudo_term_restore_v1(int fd, bool flush) { + const int flags = flush ? (TCSASOFT|TCSAFLUSH) : (TCSASOFT|TCSADRAIN); + struct termios term = { 0 }; + bool ret = false; debug_decl(sudo_term_restore, SUDO_DEBUG_UTIL); - if (changed) { - const int flags = flush ? (TCSASOFT|TCSAFLUSH) : (TCSASOFT|TCSADRAIN); - if (tcsetattr_nobg(fd, flags, &oterm) != 0) - debug_return_bool(false); - changed = 0; + if (!changed) + debug_return_bool(true); + + sudo_lock_file(fd, SUDO_LOCK); + + /* Avoid changing term settings if changed out from under us. */ + if (tcgetattr(fd, &term) == -1) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO, + "%s: tcgetattr(%d)", __func__, fd); + goto unlock; } - debug_return_bool(true); + if ((term.c_iflag & INPUT_FLAGS) != (cur_term.c_iflag & INPUT_FLAGS)) { + sudo_debug_printf(SUDO_DEBUG_INFO, "%s: not restoring terminal, " + "c_iflag changed; 0x%x, expected 0x%x", __func__, + (unsigned int)term.c_iflag, (unsigned int)cur_term.c_iflag); + /* Not an error. */ + ret = true; + goto unlock; + } + if ((term.c_oflag & OUTPUT_FLAGS) != (cur_term.c_oflag & OUTPUT_FLAGS)) { + sudo_debug_printf(SUDO_DEBUG_INFO, "%s: not restoring terminal, " + "c_oflag changed; 0x%x, expected 0x%x", __func__, + (unsigned int)term.c_oflag, (unsigned int)cur_term.c_oflag); + /* Not an error. */ + ret = true; + goto unlock; + } + if ((term.c_cflag & CONTROL_FLAGS) != (cur_term.c_cflag & CONTROL_FLAGS)) { + sudo_debug_printf(SUDO_DEBUG_INFO, "%s: not restoring terminal, " + "c_cflag changed; 0x%x, expected 0x%x", __func__, + (unsigned int)term.c_cflag, (unsigned int)cur_term.c_cflag); + /* Not an error. */ + ret = true; + goto unlock; + } + if ((term.c_lflag & LOCAL_FLAGS) != (cur_term.c_lflag & LOCAL_FLAGS)) { + sudo_debug_printf(SUDO_DEBUG_INFO, "%s: not restoring terminal, " + "c_lflag changed; 0x%x, expected 0x%x", __func__, + (unsigned int)term.c_lflag, (unsigned int)cur_term.c_lflag); + /* Not an error. */ + ret = true; + goto unlock; + } + if (memcmp(term.c_cc, cur_term.c_cc, sizeof(term.c_cc)) != 0) { + sudo_debug_printf(SUDO_DEBUG_INFO, + "%s: not restoring terminal, c_cc[] changed", __func__); + /* Not an error. */ + ret = true; + goto unlock; + } + + if (tcsetattr_nobg(fd, flags, &orig_term) == -1) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO, + "%s: tcsetattr(%d)", __func__, fd); + goto unlock; + } + cur_term = orig_term; + changed = false; + ret = true; + +unlock: + sudo_lock_file(fd, SUDO_UNLOCK); + + debug_return_bool(ret); } /* @@ -160,21 +224,75 @@ sudo_term_restore_v1(int fd, bool flush) bool sudo_term_noecho_v1(int fd) { - struct termios term; + struct termios term = { 0 }; + bool ret = false; debug_decl(sudo_term_noecho, SUDO_DEBUG_UTIL); - if (!changed && tcgetattr(fd, &oterm) != 0) - debug_return_bool(false); - (void) memcpy(&term, &oterm, sizeof(term)); + sudo_lock_file(fd, SUDO_LOCK); + if (!changed && tcgetattr(fd, &orig_term) == -1) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO, + "%s: tcgetattr(%d)", __func__, fd); + goto unlock; + } + + term = orig_term; CLR(term.c_lflag, ECHO|ECHONL); #ifdef VSTATUS term.c_cc[VSTATUS] = _POSIX_VDISABLE; #endif - if (tcsetattr_nobg(fd, TCSASOFT|TCSADRAIN, &term) == 0) { - changed = 1; - debug_return_bool(true); + if (tcsetattr_nobg(fd, TCSASOFT|TCSADRAIN, &term) == -1) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO, + "%s: tcsetattr(%d)", __func__, fd); + goto unlock; } - debug_return_bool(false); + cur_term = term; + changed = true; + ret = true; + +unlock: + sudo_lock_file(fd, SUDO_UNLOCK); + debug_return_bool(ret); +} + +/* + * Returns true if term is in raw mode, else false. + */ +static bool +sudo_term_is_raw_int(struct termios *term) +{ + debug_decl(sudo_term_is_raw_int, SUDO_DEBUG_UTIL); + + if (term->c_cc[VMIN] != 1 || term->c_cc[VTIME] != 0) + debug_return_bool(false); + + if (ISSET(term->c_oflag, OPOST)) + debug_return_bool(false); + + if (ISSET(term->c_oflag, ECHO|ECHONL|ICANON)) + debug_return_bool(false); + + debug_return_bool(true); +} + +/* + * Returns true if fd refers to a tty in raw mode, else false. + */ +bool +sudo_term_is_raw_v1(int fd) +{ + struct termios term = { 0 }; + debug_decl(sudo_term_is_raw, SUDO_DEBUG_UTIL); + + sudo_lock_file(fd, SUDO_LOCK); + if (tcgetattr(fd, &term) == -1) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO, + "%s: tcgetattr(%d)", __func__, fd); + sudo_lock_file(fd, SUDO_UNLOCK); + debug_return_bool(false); + } + sudo_lock_file(fd, SUDO_UNLOCK); + + debug_return_bool(sudo_term_is_raw_int(&term)); } /* @@ -184,28 +302,48 @@ sudo_term_noecho_v1(int fd) bool sudo_term_raw_v1(int fd, unsigned int flags) { - struct termios term; + struct termios term = { 0 }; + bool ret = false; tcflag_t oflag; debug_decl(sudo_term_raw, SUDO_DEBUG_UTIL); - if (!changed && tcgetattr(fd, &oterm) != 0) - debug_return_bool(false); - (void) memcpy(&term, &oterm, sizeof(term)); + sudo_lock_file(fd, SUDO_LOCK); + if (!changed && tcgetattr(fd, &orig_term) == -1) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO, + "%s: tcgetattr(%d)", __func__, fd); + goto unlock; + } + + if (sudo_term_is_raw_int(&term)) { + sudo_debug_printf(SUDO_DEBUG_INFO, "%s: fd %d already in raw mode", + __func__, fd); + ret = true; + goto unlock; + } + /* * Set terminal to raw mode but optionally enable terminal signals * and/or preserve output flags. */ + term = orig_term; oflag = term.c_oflag; cfmakeraw(&term); if (ISSET(flags, SUDO_TERM_ISIG)) SET(term.c_lflag, ISIG); if (ISSET(flags, SUDO_TERM_OFLAG)) term.c_oflag = oflag; - if (tcsetattr_nobg(fd, TCSASOFT|TCSADRAIN, &term) == 0) { - changed = 1; - debug_return_bool(true); + if (tcsetattr_nobg(fd, TCSASOFT|TCSADRAIN, &term) == -1) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO, + "%s: tcsetattr(%d)", __func__, fd); + goto unlock; } - debug_return_bool(false); + cur_term = term; + changed = true; + ret = true; + +unlock: + sudo_lock_file(fd, SUDO_UNLOCK); + debug_return_bool(ret); } /* @@ -215,13 +353,19 @@ sudo_term_raw_v1(int fd, unsigned int flags) bool sudo_term_cbreak_v1(int fd) { - struct termios term; + struct termios term = { 0 }; + bool ret = false; debug_decl(sudo_term_cbreak, SUDO_DEBUG_UTIL); - if (!changed && tcgetattr(fd, &oterm) != 0) - debug_return_bool(false); - (void) memcpy(&term, &oterm, sizeof(term)); + sudo_lock_file(fd, SUDO_LOCK); + if (!changed && tcgetattr(fd, &orig_term) == -1) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO, + "%s: tcgetattr(%d)", __func__, fd); + goto unlock; + } + /* Set terminal to half-cooked mode */ + term = orig_term; term.c_cc[VMIN] = 1; term.c_cc[VTIME] = 0; /* cppcheck-suppress redundantAssignment */ @@ -231,21 +375,22 @@ sudo_term_cbreak_v1(int fd) #ifdef VSTATUS term.c_cc[VSTATUS] = _POSIX_VDISABLE; #endif - if (tcsetattr_nobg(fd, TCSASOFT|TCSADRAIN, &term) == 0) { - sudo_term_eof = term.c_cc[VEOF]; - sudo_term_erase = term.c_cc[VERASE]; - sudo_term_kill = term.c_cc[VKILL]; - changed = 1; - debug_return_bool(true); + if (tcsetattr_nobg(fd, TCSASOFT|TCSADRAIN, &term) == -1) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO, + "%s: tcsetattr(%d)", __func__, fd); + goto unlock; } - debug_return_bool(false); -} + sudo_term_eof = term.c_cc[VEOF]; + sudo_term_erase = term.c_cc[VERASE]; + sudo_term_kill = term.c_cc[VKILL]; + cur_term = term; + changed = true; + ret = true; -/* Termios flags to copy between terminals. */ -#define INPUT_FLAGS (IGNPAR|PARMRK|INPCK|ISTRIP|INLCR|IGNCR|ICRNL|IUCLC|IXON|IXANY|IXOFF|IMAXBEL|IUTF8) -#define OUTPUT_FLAGS (OPOST|OLCUC|ONLCR|OCRNL|ONOCR|ONLRET) -#define CONTROL_FLAGS (CS7|CS8|PARENB|PARODD) -#define LOCAL_FLAGS (ISIG|ICANON|XCASE|ECHO|ECHOE|ECHOK|ECHONL|NOFLSH|TOSTOP|IEXTEN|ECHOCTL|ECHOKE|PENDIN) +unlock: + sudo_lock_file(fd, SUDO_UNLOCK); + debug_return_bool(ret); +} /* * Copy terminal settings from one descriptor to another. @@ -260,10 +405,16 @@ sudo_term_copy_v1(int src, int dst) struct winsize wsize; speed_t speed; unsigned int i; + bool ret = false; debug_decl(sudo_term_copy, SUDO_DEBUG_UTIL); - if (tcgetattr(src, &tt_src) != 0 || tcgetattr(dst, &tt_dst) != 0) - debug_return_bool(false); + sudo_lock_file(src, SUDO_LOCK); + sudo_lock_file(dst, SUDO_LOCK); + if (tcgetattr(src, &tt_src) == -1 || tcgetattr(dst, &tt_dst) == -1) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO, + "%s: tcgetattr", __func__); + goto unlock; + } /* Clear select input, output, control and local flags. */ CLR(tt_dst.c_iflag, INPUT_FLAGS); @@ -288,35 +439,18 @@ sudo_term_copy_v1(int src, int dst) speed = cfgetispeed(&tt_src); cfsetispeed(&tt_dst, speed); - if (tcsetattr_nobg(dst, TCSASOFT|TCSAFLUSH, &tt_dst) == -1) - debug_return_bool(false); + if (tcsetattr_nobg(dst, TCSASOFT|TCSAFLUSH, &tt_dst) == -1) { + sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_ERRNO, + "%s: tcsetattr(%d)", __func__, dst); + goto unlock; + } + ret = true; if (ioctl(src, TIOCGWINSZ, &wsize) == 0) (void)ioctl(dst, IOCTL_REQ_CAST TIOCSWINSZ, &wsize); - debug_return_bool(true); -} - -/* - * Returns true if fd refers to a tty in raw mode, else false. - */ -bool -sudo_term_is_raw_v1(int fd) -{ - struct termios term; - debug_decl(sudo_term_is_raw, SUDO_DEBUG_UTIL); - - if (tcgetattr(fd, &term) != 0) - debug_return_bool(false); - - if (term.c_cc[VMIN] != 1 || term.c_cc[VTIME] != 0) - debug_return_bool(false); - - if (ISSET(term.c_oflag, OPOST)) - debug_return_bool(false); - - if (ISSET(term.c_oflag, ECHO|ECHONL|ICANON)) - debug_return_bool(false); - - debug_return_bool(true); +unlock: + sudo_lock_file(dst, SUDO_UNLOCK); + sudo_lock_file(src, SUDO_UNLOCK); + debug_return_bool(ret); }