diff options
Diffstat (limited to 'gnulib/lib/pt_chown.c')
m--------- | gnulib | 0 | ||||
-rw-r--r-- | gnulib/lib/pt_chown.c | 162 |
2 files changed, 162 insertions, 0 deletions
diff --git a/gnulib b/gnulib deleted file mode 160000 -Subproject 443bc5ffcf7429e557f4a371b0661abe98ddbc1 diff --git a/gnulib/lib/pt_chown.c b/gnulib/lib/pt_chown.c new file mode 100644 index 0000000..ccc04fd --- /dev/null +++ b/gnulib/lib/pt_chown.c @@ -0,0 +1,162 @@ +/* pt_chown - helper program for `grantpt'. + Copyright (C) 1998-1999, 2009-2011 Free Software Foundation, Inc. + Contributed by C. Scott Ananian <cananian@alumni.princeton.edu>, 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 <http://www.gnu.org/licenses/>. */ + +#include <config.h> + +#include <errno.h> +#include <grp.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <unistd.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 (); + } + + /* It would be possible to drop setuid/setgid privileges here. But it is not + really needed, since the code below only calls strcmp and [f]printf. */ + + { + 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 <bug-gnulib@gnu.org>.\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; +} |