From: Bruno Haible Date: Sun, 21 Mar 2010 15:53:56 +0000 (+0100) Subject: New module 'pt_chown'. X-Git-Tag: v0.1~4460 X-Git-Url: http://erislabs.org.uk/gitweb/?a=commitdiff_plain;h=eae8e44ccfca3e367df3be11c3f5de48c4302093;p=gnulib.git New module 'pt_chown'. --- diff --git a/ChangeLog b/ChangeLog index 60f1da741..a1db0b37c 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,5 +1,13 @@ 2010-03-21 Bruno Haible + New module 'pt_chown'. + * lib/pt_chown.c: New file, from glibc with modifications. + * lib/pty-private.h: New file, from glibc with modifications. + * modules/pt_chown: New file. + * config/srclist.txt: Add pt_chown.c, pty-private.h (commented). + +2010-03-21 Bruno Haible + Tests for module 'ptsname'. * modules/ptsname-tests: New file. * tests/test-ptsname.c: New file. diff --git a/config/srclist.txt b/config/srclist.txt index a91eb0f57..c7e41ef64 100644 --- a/config/srclist.txt +++ b/config/srclist.txt @@ -174,6 +174,8 @@ $LIBCSRC/stdlib/strtoul.c lib gpl #$LIBCSRC/locale/programs/xmalloc.c lib gpl #$LIBCSRC/locale/programs/xstrdup.c lib gpl # +#$LIBCSRC/login/programs/pt_chown.c lib gpl +# # http://sources.redhat.com/bugzilla/show_bug.cgi?id=321 #$LIBCSRC/malloc/obstack.c lib gpl # @@ -209,6 +211,7 @@ $LIBCSRC/stdlib/strtoul.c lib gpl #$LIBCSRC/string/strcspn.c lib gpl #$LIBCSRC/string/strpbrk.c lib gpl #$LIBCSRC/string/strstr.c lib gpl +#$LIBCSRC/sysdeps/generic/pty-private.h lib gpl #$LIBCSRC/sysdeps/posix/dup2.c lib gpl #$LIBCSRC/sysdeps/posix/euidaccess.c lib gpl #$LIBCSRC/sysdeps/posix/tempname.c lib gpl diff --git a/lib/pt_chown.c b/lib/pt_chown.c new file mode 100644 index 000000000..d79ad3a87 --- /dev/null +++ b/lib/pt_chown.c @@ -0,0 +1,164 @@ +/* pt_chown - helper program for `grantpt'. + Copyright (C) 1998, 1999, 2009, 2010 Free Software Foundation, Inc. + Contributed by C. Scott Ananian , 1998. + + 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 + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . */ + +#include + +#include +#include +#include +#include +#include +#include +#include + +#include "idpriv.h" +#include "pty-private.h" + +/* For security reasons, we try to minimize the dependencies on libraries + outside libc. This means, in particular: + - No use of gettext(), since it's usually implemented in libintl. + - No use of error() or argp, since they rely on gettext by default. */ + + +static int +do_pt_chown (void) +{ + char *pty; + struct stat st; + struct group *p; + gid_t gid; + + /* Check that PTY_FILENO is a valid master pseudo terminal. */ + pty = ptsname (PTY_FILENO); + if (pty == NULL) + return errno == EBADF ? FAIL_EBADF : FAIL_EINVAL; + + /* Check that the returned slave pseudo terminal is a + character device. */ + if (stat (pty, &st) < 0 || !S_ISCHR (st.st_mode)) + return FAIL_EINVAL; + + /* Get the group ID of the special `tty' group. */ + p = getgrnam (TTY_GROUP); + gid = p ? p->gr_gid : getgid (); + + /* Set the owner to the real user ID, and the group to that special + group ID. */ + if (st.st_gid != gid && chown (pty, getuid (), gid) < 0) + return FAIL_EACCES; + + /* Set the permission mode to readable and writable by the owner, + and writable by the group. */ + if ((st.st_mode & (S_IRWXU|S_IRWXG|S_IRWXO)) != (S_IRUSR|S_IWUSR|S_IWGRP) + && chmod (pty, S_IRUSR|S_IWUSR|S_IWGRP) < 0) + return FAIL_EACCES; + + return 0; +} + + +int +main (int argc, char *argv[]) +{ + uid_t euid = geteuid (); + + if (argc == 1 && euid == 0) + { + /* Normal invocation of this program is with no arguments and + with privileges. */ + return do_pt_chown (); + } + + /* We aren't going to be using privileges, so drop them right now. */ + if (idpriv_drop () < 0) + return EXIT_FAILURE; + + { + int do_help = 0; + int do_version = 0; + int remaining; + + for (remaining = 1; remaining < argc; remaining++) + { + const char *arg = argv[remaining]; + + if (arg[0] == '-') + { + if (strcmp (arg, "--") == 0) + { + remaining++; + break; + } + else if (strcmp (arg, "--help") == 0) + do_help = 1; + else if (strcmp (arg, "--version") == 0) + do_version = 1; + else + { + fprintf (stderr, "pt_chown: invalid option: %s\n", arg); + return EXIT_FAILURE; + } + } + else + break; + } + + if (remaining < argc) + { + fprintf (stderr, "pt_chown: too many arguments\n"); + return EXIT_FAILURE; + } + + if (do_help) + { + printf ("Usage: pt_chown [OPTION...]\n"); + printf ("Set the owner, group and access permission of the slave pseudo terminal\n" + "corresponding to the master pseudo terminal passed on file descriptor %d.\n" + "This is the helper program for the 'grantpt' function. It is not intended\n" + "to be run directly from the command line.\n", + PTY_FILENO); + printf ("\n"); + printf (" --help Give this help list\n"); + printf (" --version Print program version\n"); + printf ("\n"); + printf ("The owner is set to the current user, the group is set to '%s', and the\n" + "access permission is set to '%o'.\n", + TTY_GROUP, S_IRUSR|S_IWUSR|S_IWGRP); + printf ("Please report bugs to .\n"); + return EXIT_SUCCESS; + } + + if (do_version) + { + printf ("pt_chown (GNU %s) %s\n", "libc", "2.11"); + printf ("Copyright (C) %s Free Software Foundation, Inc.\n" + "This is free software; see the source for copying conditions. There is NO\n" + "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n", + "1999"); + return EXIT_SUCCESS; + } + } + + /* Check if we are properly installed. */ + if (euid != 0) + { + fprintf (stderr, "pt_chown: needs to be installed setuid 'root'\n"); + return FAIL_EXEC; + } + + return EXIT_SUCCESS; +} diff --git a/lib/pty-private.h b/lib/pty-private.h new file mode 100644 index 000000000..32596cf32 --- /dev/null +++ b/lib/pty-private.h @@ -0,0 +1,46 @@ +/* Interface to the pt_chown program. + Copyright (C) 1998, 1999, 2009, 2010 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Zack Weinberg , 1998. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#ifndef _PTY_PRIVATE_H +#define _PTY_PRIVATE_H 1 + +/* The group slave pseudo terminals belong to. */ +#define TTY_GROUP "tty" + +/* The file descriptor connected to the master pseudo terminal. */ +#define PTY_FILENO 3 + +/* Path to the helper program that implements `grantpt' in user space. */ +#define _PATH_PT_CHOWN PKGLIBEXECDIR "/pt_chown" + +/* Test whether given TTY is really a Unix98 pseudo terminal. */ +/* #define unix98_pseudo_p(Dev) ... */ + +/* Exit codes for the helper program. */ +enum /* failure modes */ +{ + FAIL_EBADF = 1, + FAIL_EINVAL, + FAIL_EACCES, + FAIL_EXEC, + FAIL_ENOMEM +}; + +#endif /* pty-private.h */ diff --git a/modules/pt_chown b/modules/pt_chown new file mode 100644 index 000000000..8cae3d148 --- /dev/null +++ b/modules/pt_chown @@ -0,0 +1,25 @@ +Description: +Helper program for setting the owner of the slave side of a pseudo-terminal. + +Files: +lib/pt_chown.c +lib/pty-private.h + +Depends-on: +idpriv-drop +ptsname + +configure.ac: + +Makefile.am: +# TODO: Add rules for installing as setuid root (chown root, chmod a=rx,u+s). +pkglibexec_PROGRAMS = pt_chown +pt_chown_LDADD = libgnu.a + +Include: + +License: +LGPL + +Maintainer: +glibc