--- rxvt-unicode/src/ptytty.C 2006/01/17 15:41:33 1.41 +++ rxvt-unicode/src/ptytty.C 2006/01/22 12:21:47 1.57 @@ -1,10 +1,14 @@ -/*--------------------------------*-C-*---------------------------------* +// This file is part of libptytty. Do not make local modifications. +// http://software.schmorp.de/pkg/libptytty + +/*----------------------------------------------------------------------* * File: ptytty.C *----------------------------------------------------------------------* * * All portions of code are copyright by their respective author/s. * Copyright (c) 1999-2001 Geoff Wing * Copyright (c) 2004-2006 Marc Lehmann + * Copyright (c) 2006 Emanuele Giaquinta * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -21,8 +25,9 @@ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. *---------------------------------------------------------------------*/ -#include "../config.h" /* NECESSARY */ -#include "rxvt.h" +#include "../config.h" + +#include "ptytty.h" #include #include @@ -35,7 +40,7 @@ #ifdef HAVE_SYS_IOCTL_H # include #endif -#if defined(PTYS_ARE_PTMX) && defined(HAVE_SYS_STROPTS_H) +#if defined(HAVE_DEV_PTMX) && defined(HAVE_SYS_STROPTS_H) # include /* for I_PUSH */ #endif #ifdef HAVE_ISASTREAM @@ -48,13 +53,11 @@ #elif defined(HAVE_UTIL_H) # include #endif - -#include +#ifdef TTY_GID_SUPPORT #include +#endif -#include "rxvtutil.h" -#include "fdpass.h" -#include "ptytty.h" +#include ///////////////////////////////////////////////////////////////////////////// @@ -66,144 +69,122 @@ * If successful, ttydev is set to the name of the slave device. * fd_tty _may_ also be set to an open fd to the slave device */ +#if defined(UNIX98_PTY) static int get_pty (int *fd_tty, char **ttydev) { int pfd; -#ifdef PTYS_ARE_OPENPTY - char tty_name[sizeof "/dev/pts/????\0"]; +# if defined(HAVE_GETPT) + pfd = getpt(); +# elif defined(HAVE_POSIX_OPENPT) + pfd = posix_openpt (O_RDWR); +# else + pfd = open (CLONE_DEVICE, O_RDWR | O_NOCTTY, 0); +# endif + if (pfd >= 0) + { + if (grantpt (pfd) == 0 /* change slave permissions */ + && unlockpt (pfd) == 0) + { /* slave now unlocked */ + *ttydev = strdup (ptsname (pfd)); /* get slave's name */ + return pfd; + } - int res = openpty (&pfd, fd_tty, tty_name, NULL, NULL); + close (pfd); + } + return -1; +} +#elif defined(HAVE_OPENPTY) +static int +get_pty (int *fd_tty, char **ttydev) +{ + int pfd; + int res; + char tty_name[32]; + + res = openpty (&pfd, fd_tty, tty_name, NULL, NULL); if (res != -1) { *ttydev = strdup (tty_name); return pfd; } -#endif -#ifdef PTYS_ARE__GETPTY + return -1; +} +#elif defined(HAVE__GETPTY) +static int +get_pty (int *fd_tty, char **ttydev) +{ + int pfd; + *ttydev = _getpty (&pfd, O_RDWR | O_NONBLOCK | O_NOCTTY, 0622, 0); if (*ttydev != NULL) return pfd; -#endif -#if defined(HAVE_GRANTPT) && defined(HAVE_UNLOCKPT) -# if defined(PTYS_ARE_GETPT) || defined(PTYS_ARE_POSIX) || defined(PTYS_ARE_PTMX) - - { -# ifdef PTYS_ARE_GETPT - pfd = getpt(); -# else -# ifdef PTYS_ARE_POSIX - pfd = posix_openpt (O_RDWR); -# else - pfd = open ("/dev/ptmx", O_RDWR | O_NOCTTY, 0); -# endif -# endif - - if (pfd >= 0) - { - if (grantpt (pfd) == 0 /* change slave permissions */ - && unlockpt (pfd) == 0) - { /* slave now unlocked */ - *ttydev = strdup (ptsname (pfd)); /* get slave's name */ - return pfd; - } - close (pfd); - } - } -# endif -#endif + return -1; +} +#elif defined(HAVE_DEV_PTC) +static int +get_pty (int *fd_tty, char **ttydev) +{ + int pfd; -#ifdef PTYS_ARE_PTC if ((pfd = open ("/dev/ptc", O_RDWR | O_NOCTTY, 0)) >= 0) { *ttydev = strdup (ttyname (pfd)); return pfd; } -#endif -#ifdef PTYS_ARE_CLONE + return -1; +} +#elif defined(HAVE_DEV_CLONE) +static int +get_pty (int *fd_tty, char **ttydev) +{ + int pfd; + if ((pfd = open ("/dev/ptym/clone", O_RDWR | O_NOCTTY, 0)) >= 0) { *ttydev = strdup (ptsname (pfd)); return pfd; } -#endif - -#ifdef PTYS_ARE_NUMERIC - { - int idx; - char *c1, *c2; - char pty_name[] = "/dev/ptyp???"; - char tty_name[] = "/dev/ttyp???"; - - c1 = &(pty_name[sizeof (pty_name) - 4]); - c2 = &(tty_name[sizeof (tty_name) - 4]); - for (idx = 0; idx < 256; idx++) - { - sprintf (c1, "%d", idx); - sprintf (c2, "%d", idx); - if (access (tty_name, F_OK) < 0) - { - idx = 256; - break; - } - - if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) >= 0) - { - if (access (tty_name, R_OK | W_OK) == 0) - { - *ttydev = strdup (tty_name); - return pfd; - } - - close (pfd); - } - } - } -#endif - -#ifdef PTYS_ARE_SEARCHED - { - const char *c1, *c2; - char pty_name[] = "/dev/pty??"; - char tty_name[] = "/dev/tty??"; - -# ifndef PTYCHAR1 -# define PTYCHAR1 "pqrstuvwxyz" -# endif -# ifndef PTYCHAR2 -# define PTYCHAR2 "0123456789abcdef" -# endif - - for (c1 = PTYCHAR1; *c1; c1++) - { - pty_name[ (sizeof (pty_name) - 3)] = - tty_name[ (sizeof (pty_name) - 3)] = *c1; - for (c2 = PTYCHAR2; *c2; c2++) - { - pty_name[ (sizeof (pty_name) - 2)] = - tty_name[ (sizeof (pty_name) - 2)] = *c2; - if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) >= 0) - { - if (access (tty_name, R_OK | W_OK) == 0) - { - *ttydev = strdup (tty_name); - return pfd; - } - - close (pfd); - } - } - } - } -#endif return -1; } +#else +/* Based on the code in openssh/openbsd-compat/bsd-openpty.c */ +static int +get_pty (int *fd_tty, char **ttydev) +{ + int pfd; + int i; + char pty_name[32]; + char tty_name[32]; + const char *majors = "pqrstuvwxyzabcde"; + const char *minors = "0123456789abcdef"; + for (i = 0; i < 256; i++) + { + snprintf(pty_name, 32, "/dev/pty%c%c", majors[i / 16], minors[i % 16]); + snprintf(tty_name, 32, "/dev/tty%c%c", majors[i / 16], minors[i % 16]); + if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) == -1) + { + snprintf(pty_name, 32, "/dev/ptyp%d", i); + snprintf(tty_name, 32, "/dev/ttyp%d", i); + if ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) == -1) + continue; + } + if (access (tty_name, R_OK | W_OK) == 0) + { + *ttydev = strdup (tty_name); + return pfd; + } + + close (pfd); + } +} +#endif /*----------------------------------------------------------------------*/ /* @@ -222,13 +203,9 @@ static int control_tty (int fd_tty) { - int fd; - - /* ---------------------------------------- */ setsid (); - /* ---------------------------------------- */ -# if defined(PTYS_ARE_PTMX) && defined(I_PUSH) +#if defined(HAVE_DEV_PTMX) && defined(I_PUSH) /* * Push STREAMS modules: * ptem: pseudo-terminal hardware emulation module. @@ -246,29 +223,29 @@ * close () - on the master side which causes a hang up to be sent * through - Geoff Wing */ -# ifdef HAVE_ISASTREAM +# ifdef HAVE_ISASTREAM if (isastream (fd_tty) == 1) -# endif +# endif { ioctl (fd_tty, I_PUSH, "ptem"); ioctl (fd_tty, I_PUSH, "ldterm"); ioctl (fd_tty, I_PUSH, "ttcompat"); } -# endif - /* ---------------------------------------- */ - fd = ioctl (fd_tty, TIOCSCTTY, NULL); - /* ---------------------------------------- */ - fd = open ("/dev/tty", O_WRONLY); +#endif + + ioctl (fd_tty, TIOCSCTTY, NULL); + + int fd = open ("/dev/tty", O_WRONLY); if (fd < 0) - return -1; /* fatal */ + return -1; /* fatal */ + close (fd); - /* ---------------------------------------- */ return 0; } void -rxvt_ptytty::close_tty () +ptytty::close_tty () { if (tty < 0) return; @@ -278,13 +255,13 @@ } bool -rxvt_ptytty::make_controlling_tty () +ptytty::make_controlling_tty () { return control_tty (tty) >= 0; } void -rxvt_ptytty::set_utf8_mode (bool on) +ptytty::set_utf8_mode (bool on) { #ifdef IUTF8 if (pty < 0) @@ -310,9 +287,6 @@ #endif } -///////////////////////////////////////////////////////////////////////////// - -#ifndef NO_SETOWNER_TTYDEV static struct ttyconf { gid_t gid; mode_t mode; @@ -331,80 +305,38 @@ #endif /* TTY_GID_SUPPORT */ { mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH; - gid = getgid (); + gid = 0; } } } ttyconf; -///////////////////////////////////////////////////////////////////////////// - -void -rxvt_ptytty_unix::privileges (rxvt_privaction action) -{ - if (!name || !*name) - return; - - if (action == SAVE) - { -# ifndef RESET_TTY_TO_COMMON_DEFAULTS - /* store original tty status for restoration rxvt_clean_exit () -- rgg 04/12/95 */ - if (lstat (name, &savestat) < 0) /* you lose out */ - ; - else -# endif - { - saved = true; - chown (name, getuid (), ttyconf.gid); /* fail silently */ - chmod (name, ttyconf.mode); -# ifdef HAVE_REVOKE - revoke (name); -# endif - } - } - else - { /* action == RESTORE */ -# ifndef RESET_TTY_TO_COMMON_DEFAULTS - if (saved) - { - chmod (name, savestat.st_mode); - chown (name, savestat.st_uid, savestat.st_gid); - } -# else - chmod (name, (S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH)); - chown (name, 0, 0); -# endif - - } -} -#endif - -rxvt_ptytty_unix::rxvt_ptytty_unix () +ptytty_unix::ptytty_unix () { - pty = tty = -1; name = 0; -#ifndef NO_SETOWNER_TTYDEV - saved = false; -#endif #if UTMP_SUPPORT cmd_pid = 0; #endif } -rxvt_ptytty_unix::~rxvt_ptytty_unix () +ptytty_unix::~ptytty_unix () { +#if UTMP_SUPPORT logout (); +#endif put (); } void -rxvt_ptytty_unix::put () +ptytty_unix::put () { -#ifndef NO_SETOWNER_TTYDEV - privileges (RESTORE); -#endif + chmod (name, RESTORE_TTY_MODE); + chown (name, 0, ttyconf.gid); - if (pty >= 0) close (pty); close_tty (); + + if (pty >= 0) + close (pty); + free (name); pty = tty = -1; @@ -412,7 +344,7 @@ } bool -rxvt_ptytty_unix::get () +ptytty_unix::get () { /* get master (pty) */ if ((pty = get_pty (&tty, &name)) < 0) @@ -424,7 +356,11 @@ if (tty < 0) { #ifndef NO_SETOWNER_TTYDEV - privileges (SAVE); + chown (name, getuid (), ttyconf.gid); /* fail silently */ + chmod (name, ttyconf.mode); +# ifdef HAVE_REVOKE + revoke (name); +# endif #endif if ((tty = get_tty (name)) < 0) @@ -439,32 +375,37 @@ #if PTYTTY_HELPER -static int sock_fd; -static int pid; +static int sock_fd = -1; +static int helper_pid, owner_pid; struct command { enum { get, login, destroy } type; - rxvt_ptytty *id; + ptytty *id; bool login_shell; int cmd_pid; char hostname[512]; // arbitrary, but should be plenty }; -struct rxvt_ptytty_proxy : zero_initialized, rxvt_ptytty +struct ptytty_proxy : ptytty { - rxvt_ptytty *id; + ptytty *id; + + ptytty_proxy () + : id(0) + { + } - ~rxvt_ptytty_proxy (); + ~ptytty_proxy (); bool get (); void login (int cmd_pid, bool login_shell, const char *hostname); }; bool -rxvt_ptytty_proxy::get () +ptytty_proxy::get () { command cmd; @@ -473,20 +414,20 @@ write (sock_fd, &cmd, sizeof (cmd)); if (read (sock_fd, &id, sizeof (id)) != sizeof (id)) - rxvt_fatal ("protocol error while creating pty using helper process, aborting.\n"); + ptytty_fatal ("protocol error while creating pty using helper process, aborting.\n"); if (!id) return false; - if ((pty = rxvt_recv_fd (sock_fd)) < 0 - || (tty = rxvt_recv_fd (sock_fd)) < 0) - rxvt_fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n"); + if ((pty = recv_fd (sock_fd)) < 0 + || (tty = recv_fd (sock_fd)) < 0) + ptytty_fatal ("protocol error while reading pty/tty fds from helper process, aborting.\n"); return true; } void -rxvt_ptytty_proxy::login (int cmd_pid, bool login_shell, const char *hostname) +ptytty_proxy::login (int cmd_pid, bool login_shell, const char *hostname) { command cmd; @@ -499,36 +440,39 @@ write (sock_fd, &cmd, sizeof (cmd)); } -rxvt_ptytty_proxy::~rxvt_ptytty_proxy () +ptytty_proxy::~ptytty_proxy () { - command cmd; + if (id) + { + command cmd; - cmd.type = command::destroy; - cmd.id = id; + cmd.type = command::destroy; + cmd.id = id; - write (sock_fd, &cmd, sizeof (cmd)); + write (sock_fd, &cmd, sizeof (cmd)); + } } static void serve () { command cmd; - vector ptys; + vector ptys; while (read (sock_fd, &cmd, sizeof (command)) == sizeof (command)) { if (cmd.type == command::get) { // -> id ptyfd ttyfd - cmd.id = new rxvt_ptytty_unix; + cmd.id = new ptytty_unix; if (cmd.id->get ()) { write (sock_fd, &cmd.id, sizeof (cmd.id)); ptys.push_back (cmd.id); - rxvt_send_fd (sock_fd, cmd.id->pty); - rxvt_send_fd (sock_fd, cmd.id->tty); + ptytty::send_fd (sock_fd, cmd.id->pty); + ptytty::send_fd (sock_fd, cmd.id->tty); } else { @@ -539,20 +483,22 @@ } else if (cmd.type == command::login) { +#if UTMP_SUPPORT if (find (ptys.begin (), ptys.end (), cmd.id)) { cmd.hostname[sizeof (cmd.hostname) - 1] = 0; cmd.id->login (cmd.cmd_pid, cmd.login_shell, cmd.hostname); } +#endif } else if (cmd.type == command::destroy) { - rxvt_ptytty **pty = find (ptys.begin (), ptys.end (), cmd.id); + vector::iterator pty = find (ptys.begin (), ptys.end (), cmd.id); - if (*pty) + if (pty != ptys.end ()) { - ptys.erase (pty); delete *pty; + ptys.erase (pty); } } else @@ -560,37 +506,44 @@ } // destroy all ptys - for (rxvt_ptytty **i = ptys.end (); i-- > ptys.begin (); ) + for (vector::iterator i = ptys.end (); i-- > ptys.begin (); ) delete *i; } -void rxvt_ptytty_server () +void +ptytty::use_helper () { + int pid = getpid (); + + if (sock_fd >= 0 && pid == owner_pid) + return; + + owner_pid = pid; + int sv[2]; if (socketpair (AF_UNIX, SOCK_STREAM, 0, sv)) - rxvt_fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n"); + ptytty_fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n"); - pid = fork (); + helper_pid = fork (); - if (pid < 0) - rxvt_fatal ("could not create pty/sessiondb helper process, aborting.\n"); + if (helper_pid < 0) + ptytty_fatal ("could not create pty/sessiondb helper process, aborting.\n"); - if (pid) + if (helper_pid) { - // client, urxvt + // client, process sock_fd = sv[0]; close (sv[1]); fcntl (sock_fd, F_SETFD, FD_CLOEXEC); } else { - setgid (getegid ()); - setuid (geteuid ()); - // server, pty-helper sock_fd = sv[1]; + chdir ("/"); + for (int fd = 0; fd < 1023; fd++) if (fd != sock_fd) close (fd); @@ -599,20 +552,62 @@ _exit (EXIT_SUCCESS); } } + #endif -// a "factory" *g* -rxvt_ptytty * -rxvt_new_ptytty () +ptytty * +ptytty::create () { #if PTYTTY_HELPER - if (pid > 0) + if (helper_pid && getpid () == owner_pid) // use helper process - return new rxvt_ptytty_proxy; + return new ptytty_proxy; else #endif - return new rxvt_ptytty_unix; + return new ptytty_unix; +} + +void +ptytty::init () +{ + uid_t uid = getuid (); + gid_t gid = getgid (); + + // before doing anything else, check for setuid/setgid operation, + // start the helper process and drop privileges + if (uid != geteuid () + || gid != getegid ()) + { +#if PTYTTY_HELPER + use_helper (); +#else + ptytty_warn ("running setuid/setgid without pty helper compiled in, continuing unprivileged.\n"); +#endif + + drop_privileges (); + } } -/*----------------------- end-of-file (C source) -----------------------*/ +void +ptytty::drop_privileges () +{ + uid_t uid = getuid (); + gid_t gid = getgid (); + + // drop privileges +#if HAVE_SETRESUID + setresgid (gid, gid, gid); + setresuid (uid, uid, uid); +#elif HAVE_SETREUID + setregid (gid, gid); + setreuid (uid, uid); +#elif HAVE_SETUID + setgid (gid); + setuid (uid); +#endif + + if (uid != geteuid () + || gid != getegid ()) + ptytty_fatal ("unable to drop privileges, aborting.\n"); +}