--- rxvt-unicode/src/ptytty.C 2006/01/19 16:43:36 1.50 +++ 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 ///////////////////////////////////////////////////////////////////////////// @@ -66,19 +69,18 @@ * 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) { -#if defined(HAVE_GRANTPT) && defined(HAVE_UNLOCKPT) -# if defined(PTYS_ARE_GETPT) || defined(PTYS_ARE_POSIX) || defined(PTYS_ARE_PTMX) int pfd; -# if defined(PTYS_ARE_GETPT) +# if defined(HAVE_GETPT) pfd = getpt(); -# elif defined(PTYS_ARE_POSIX) +# elif defined(HAVE_POSIX_OPENPT) pfd = posix_openpt (O_RDWR); # else - pfd = open ("/dev/ptmx", O_RDWR | O_NOCTTY, 0); + pfd = open (CLONE_DEVICE, O_RDWR | O_NOCTTY, 0); # endif if (pfd >= 0) { @@ -91,19 +93,16 @@ close (pfd); } -# endif -#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) @@ -111,29 +110,25 @@ *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) @@ -141,15 +136,13 @@ *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) @@ -157,109 +150,41 @@ *ttydev = strdup (ptsname (pfd)); return pfd; } -#endif return -1; } - -static inline int -get_pty_numeric (int *fd_tty, char **ttydev) +#else +/* Based on the code in openssh/openbsd-compat/bsd-openpty.c */ +static int +get_pty (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) + 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) { - idx = 256; - break; + 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 ((pfd = open (pty_name, O_RDWR | O_NOCTTY, 0)) >= 0) + if (access (tty_name, R_OK | W_OK) == 0) { - if (access (tty_name, R_OK | W_OK) == 0) - { - *ttydev = strdup (tty_name); - return pfd; - } - - close (pfd); + *ttydev = strdup (tty_name); + return 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); - } - } + close (pfd); } -#endif - - return -1; -} - -static int -get_pty (int *fd_tty, char **ttydev) -{ - int 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; } +#endif /*----------------------------------------------------------------------*/ /* @@ -280,7 +205,7 @@ { 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. @@ -312,7 +237,7 @@ int fd = open ("/dev/tty", O_WRONLY); if (fd < 0) - return -1; /* fatal */ + return -1; /* fatal */ close (fd); @@ -320,7 +245,7 @@ } void -rxvt_ptytty::close_tty () +ptytty::close_tty () { if (tty < 0) return; @@ -330,13 +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) @@ -385,16 +310,15 @@ } } ttyconf; -rxvt_ptytty_unix::rxvt_ptytty_unix () +ptytty_unix::ptytty_unix () { - pty = tty = -1; name = 0; #if UTMP_SUPPORT cmd_pid = 0; #endif } -rxvt_ptytty_unix::~rxvt_ptytty_unix () +ptytty_unix::~ptytty_unix () { #if UTMP_SUPPORT logout (); @@ -403,7 +327,7 @@ } void -rxvt_ptytty_unix::put () +ptytty_unix::put () { chmod (name, RESTORE_TTY_MODE); chown (name, 0, ttyconf.gid); @@ -420,7 +344,7 @@ } bool -rxvt_ptytty_unix::get () +ptytty_unix::get () { /* get master (pty) */ if ((pty = get_pty (&tty, &name)) < 0) @@ -451,32 +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; @@ -485,20 +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; @@ -511,36 +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 { @@ -561,9 +493,9 @@ } 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); @@ -574,25 +506,33 @@ } // 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); @@ -602,6 +542,8 @@ // server, pty-helper sock_fd = sv[1]; + chdir ("/"); + for (int fd = 0; fd < 1023; fd++) if (fd != sock_fd) close (fd); @@ -613,18 +555,59 @@ #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"); +}