--- rxvt-unicode/src/ptytty.C 2006/01/17 17:59:31 1.44 +++ rxvt-unicode/src/ptytty.C 2006/01/23 12:37:59 1.60 @@ -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 @@ -21,11 +25,13 @@ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. *---------------------------------------------------------------------*/ -#include "../config.h" /* NECESSARY */ -#include "rxvt.h" +#include "../config.h" + +#include "ptytty.h" #include #include +#include #include #include @@ -35,7 +41,7 @@ #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 +54,11 @@ #elif defined(HAVE_UTIL_H) # include #endif - -#include +#ifdef TTY_GID_SUPPORT #include +#endif -#include "rxvtutil.h" -#include "fdpass.h" -#include "ptytty.h" +#include ///////////////////////////////////////////////////////////////////////////// @@ -66,20 +70,18 @@ * 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 */ -static inline int -get_pty_streams (int *fd_tty, char **ttydev) +#if defined(UNIX98_PTY) +static int +get_pty (int *fd_tty, char **ttydev) { -#ifdef NO_SETOWNER_TTYDEV int pfd; -# ifdef PTYS_ARE_GETPT +# if defined(HAVE_GETPT) pfd = getpt(); -# else -# ifdef PTYS_ARE_POSIX +# elif defined(HAVE_POSIX_OPENPT) pfd = posix_openpt (O_RDWR); # else - pfd = open ("/dev/ptmx", O_RDWR | O_NOCTTY, 0); -# endif + pfd = open (CLONE_DEVICE, O_RDWR | O_NOCTTY, 0); # endif if (pfd >= 0) { @@ -89,19 +91,19 @@ *ttydev = strdup (ptsname (pfd)); /* get slave's name */ return pfd; } + close (pfd); } -#endif + return -1; } - -static inline int -get_pty_openpty (int *fd_tty, char **ttydev) +#elif defined(HAVE_OPENPTY) +static int +get_pty (int *fd_tty, char **ttydev) { -#ifdef PTYS_ARE_OPENPTY int pfd; int res; - char tty_name[sizeof "/dev/pts/????\0"]; + char tty_name[32]; res = openpty (&pfd, fd_tty, tty_name, NULL, NULL); if (res != -1) @@ -109,27 +111,25 @@ *ttydev = strdup (tty_name); return pfd; } -#endif + return -1; } - -static inline int -get_pty__getpty (int *fd_tty, char **ttydev) +#elif defined(HAVE__GETPTY) +static int +get_pty (int *fd_tty, char **ttydev) { -#ifdef PTYS_ARE__GETPTY int pfd; *ttydev = _getpty (&pfd, O_RDWR | O_NONBLOCK | O_NOCTTY, 0622, 0); if (*ttydev != NULL) return pfd; -#endif + return -1; } - -static inline int -get_pty_ptc (int *fd_tty, char **ttydev) +#elif defined(HAVE_DEV_PTC) +static int +get_pty (int *fd_tty, char **ttydev) { -#ifdef PTYS_ARE_PTC int pfd; if ((pfd = open ("/dev/ptc", O_RDWR | O_NOCTTY, 0)) >= 0) @@ -137,14 +137,13 @@ *ttydev = strdup (ttyname (pfd)); return pfd; } -#endif + return -1; } - -static inline int -get_pty_clone (int *fd_tty, char **ttydev) +#elif defined(HAVE_DEV_CLONE) +static int +get_pty (int *fd_tty, char **ttydev) { -#ifdef PTYS_ARE_CLONE int pfd; if ((pfd = open ("/dev/ptym/clone", O_RDWR | O_NOCTTY, 0)) >= 0) @@ -152,101 +151,41 @@ *ttydev = strdup (ptsname (pfd)); return pfd; } -#endif - return -1; -} -static inline int -get_pty_numeric (int *fd_tty, char **ttydev) -{ -#ifdef PTYS_ARE_NUMERIC - int pfd; - 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 - return -1; -} - -static inline int -get_pty_searched (int *fd_tty, char **ttydev) -{ -#ifdef PTYS_ARE_SEARCHED -# ifndef PTYCHAR1 -# define PTYCHAR1 "pqrstuvwxyz" -# endif -# ifndef PTYCHAR2 -# define PTYCHAR2 "0123456789abcdef" -# endif - int pfd; - const char *c1, *c2; - char pty_name[] = "/dev/pty??"; - char tty_name[] = "/dev/tty??"; - - 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; + 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; + } - if ((pfd = get_pty_streams (fd_tty, ttydev)) != -1 - || (pfd = get_pty_openpty (fd_tty, ttydev)) != -1 - || (pfd = get_pty__getpty (fd_tty, ttydev)) != -1 - || (pfd = get_pty_ptc (fd_tty, ttydev)) != -1 - || (pfd = get_pty_clone (fd_tty, ttydev)) != -1 - || (pfd = get_pty_numeric (fd_tty, ttydev)) != -1 - || (pfd = get_pty_searched (fd_tty, ttydev)) != -1) - return pfd; - return -1; + close (pfd); + } } +#endif /*----------------------------------------------------------------------*/ /* @@ -265,13 +204,9 @@ 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. @@ -289,29 +224,29 @@ * 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; @@ -321,13 +256,13 @@ } 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) @@ -353,9 +288,6 @@ #endif } -///////////////////////////////////////////////////////////////////////////// - -#ifndef NO_SETOWNER_TTYDEV static struct ttyconf { gid_t gid; mode_t mode; @@ -374,66 +306,20 @@ #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) +ptytty_unix::ptytty_unix () { - 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 () -{ - 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 (); @@ -442,14 +328,16 @@ } 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; @@ -457,7 +345,7 @@ } bool -rxvt_ptytty_unix::get () +ptytty_unix::get () { /* get master (pty) */ if ((pty = get_pty (&tty, &name)) < 0) @@ -469,7 +357,11 @@ 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) @@ -482,35 +374,53 @@ return true; } +///////////////////////////////////////////////////////////////////////////// +// helper/proxy support + #if PTYTTY_HELPER -static int sock_fd; -static int pid; +static int sock_fd = -1, lock_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); }; +#if PTYTTY_REENTRANT +# define NEED_TOKEN do { char ch; read (lock_fd, &ch, 1); } while (0) +# define GIVE_TOKEN do { char ch; write (lock_fd, &ch, 1); } while (0) +#else +# define NEED_TOKEN (void)0 +# define GIVE_TOKEN (void)0 +#endif + bool -rxvt_ptytty_proxy::get () +ptytty_proxy::get () { + NEED_TOKEN; + command cmd; cmd.type = command::get; @@ -518,21 +428,27 @@ 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; + { + GIVE_TOKEN; + 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"); + GIVE_TOKEN; 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) { + NEED_TOKEN; + command cmd; cmd.type = command::login; @@ -542,38 +458,52 @@ strncpy (cmd.hostname, hostname, sizeof (cmd.hostname)); write (sock_fd, &cmd, sizeof (cmd)); + + GIVE_TOKEN; } -rxvt_ptytty_proxy::~rxvt_ptytty_proxy () +ptytty_proxy::~ptytty_proxy () { - command cmd; + if (id) + { + NEED_TOKEN; - cmd.type = command::destroy; - cmd.id = id; + command cmd; - write (sock_fd, &cmd, sizeof (cmd)); + cmd.type = command::destroy; + cmd.id = id; + + write (sock_fd, &cmd, sizeof (cmd)); + + GIVE_TOKEN; + } } static void serve () { command cmd; - vector ptys; + vector ptys; - while (read (sock_fd, &cmd, sizeof (command)) == sizeof (command)) + for (;;) { + GIVE_TOKEN; + + if (read (sock_fd, &cmd, sizeof (command)) != sizeof (command)) + break; + 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 { @@ -585,7 +515,7 @@ else if (cmd.type == command::login) { #if UTMP_SUPPORT - if (find (ptys.begin (), ptys.end (), cmd.id)) + if (find (ptys.begin (), ptys.end (), cmd.id) != ptys.end ()) { cmd.hostname[sizeof (cmd.hostname) - 1] = 0; cmd.id->login (cmd.cmd_pid, cmd.login_shell, cmd.hostname); @@ -594,9 +524,9 @@ } 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 ()) { delete *pty; ptys.erase (pty); @@ -604,62 +534,183 @@ } else break; + + NEED_TOKEN; } // 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 () { +#ifndef PTYTTY_NO_PID_CHECK + int pid = getpid (); +#endif + + if (sock_fd >= 0 +#ifndef PTYTTY_NO_PID_CHECK + && pid == owner_pid +#endif + ) + return; + +#ifndef PTYTTY_NO_PID_CHECK + owner_pid = pid; +#endif + 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"); + +#ifdef PTYTTY_REENTRANT + int lv[2]; + + if (socketpair (AF_UNIX, SOCK_STREAM, 0, lv)) + ptytty_fatal ("could not create socket to communicate with pty/sessiondb helper, aborting.\n"); +#endif - 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); +#ifdef PTYTTY_REENTRANT + lock_fd = lv[0]; + close (lv[1]); + fcntl (lock_fd, F_SETFD, FD_CLOEXEC); +#endif } else { - setgid (getegid ()); - setuid (geteuid ()); - // server, pty-helper sock_fd = sv[1]; +#ifdef PTYTTY_REENTRANT + lock_fd = lv[1]; +#endif + + chdir ("/"); + + signal (SIGHUP, SIG_IGN); + signal (SIGTERM, SIG_IGN); + signal (SIGINT, SIG_IGN); + signal (SIGPIPE, SIG_IGN); for (int fd = 0; fd < 1023; fd++) - if (fd != sock_fd && fd != 1) + if (fd != sock_fd && fd != lock_fd) close (fd); serve (); _exit (EXIT_SUCCESS); } } + #endif -// a "factory" *g* -rxvt_ptytty * -rxvt_new_ptytty () +ptytty * +ptytty::create () { #if PTYTTY_HELPER - if (pid > 0) + if (helper_pid +# ifndef PTYTTY_NO_PID_CHECK + && getpid () == owner_pid +# endif + ) // 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 (); + } +} + +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"); +} + +///////////////////////////////////////////////////////////////////////////// +// C API + +#ifndef PTYTTY_NO_C_API + +typedef void *PTYTTY; + +#define DEFINE_METHOD(retval, name, args1, args2) \ +extern "C" retval ptytty_ ## name args1 \ +{ return ((struct ptytty *)ptytty)->name args2; } + +DEFINE_METHOD(int,pty,(PTYTTY ptytty),) +DEFINE_METHOD(int,tty,(PTYTTY ptytty),) +DEFINE_METHOD(int,get,(PTYTTY ptytty),()) +DEFINE_METHOD(void,login,(PTYTTY ptytty, int cmd_pid, bool login_shell, const char *hostname),(cmd_pid,login_shell,hostname)) + +DEFINE_METHOD(void,close_tty,(PTYTTY ptytty),()) +DEFINE_METHOD(int,make_controlling_tty,(PTYTTY ptytty),()) +DEFINE_METHOD(void,set_utf8_mode,(PTYTTY ptytty, int on),(on)) + +#define DEFINE_STATIC(retval, name, args) \ +extern "C" retval ptytty_ ## name args \ +{ return ptytty::name args; } + +DEFINE_STATIC(void,drop_privileges,()) +DEFINE_STATIC(void,use_helper,()) +DEFINE_STATIC(void,init,()) + +DEFINE_STATIC(PTYTTY ,create,()) + +void ptytty_delete (PTYTTY ptytty) +{ + delete (struct ptytty *)ptytty; } -/*----------------------- end-of-file (C source) -----------------------*/ +// send_fd, recv_fd not exposed +#endif