[134] | 1 | /* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 8 -*- |
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| 2 | * |
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| 3 | * Copyright (C) 2007 William Jon McCann <mccann@jhu.edu> |
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| 4 | * |
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| 5 | * This library is free software; you can redistribute it and/or |
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| 6 | * modify it under the terms of the GNU Library General Public |
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| 7 | * License as published by the Free Software Foundation; either |
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| 8 | * version 2 of the License, or (at your option) any later version. |
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| 9 | * |
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| 10 | * This library is distributed in the hope that it will be useful, |
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| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 13 | * Library General Public License for more details. |
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| 14 | * |
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| 15 | * You should have received a copy of the GNU Library General Public |
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| 16 | * License along with this library; if not, write to the |
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| 17 | * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
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| 18 | * Boston, MA 02111-1307, USA. |
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| 19 | */ |
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| 20 | |
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| 21 | #include "config.h" |
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| 22 | |
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| 23 | #include <string.h> |
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| 24 | #include <unistd.h> |
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| 25 | #include <stdlib.h> |
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| 26 | #include <locale.h> |
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| 27 | #include <fcntl.h> |
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| 28 | #include <sys/wait.h> |
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| 29 | |
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| 30 | #include <glib.h> |
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| 31 | #include <glib/gi18n.h> |
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| 32 | #include <glib/gstdio.h> |
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| 33 | |
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| 34 | #include "gdm-common.h" |
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| 35 | |
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| 36 | #ifndef HAVE_MKDTEMP |
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| 37 | #include "mkdtemp.h" |
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| 38 | #endif |
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| 39 | |
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| 40 | const char * |
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| 41 | gdm_make_temp_dir (char *template) |
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| 42 | { |
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| 43 | return mkdtemp (template); |
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| 44 | } |
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| 45 | |
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| 46 | gboolean |
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| 47 | gdm_is_version_unstable (void) |
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| 48 | { |
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| 49 | char **versions; |
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| 50 | gboolean unstable; |
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| 51 | |
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| 52 | unstable = FALSE; |
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| 53 | |
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| 54 | versions = g_strsplit (VERSION, ".", 3); |
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| 55 | if (versions && versions [0] && versions [1]) { |
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| 56 | int major; |
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| 57 | major = atoi (versions [1]); |
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| 58 | if ((major % 2) != 0) { |
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| 59 | unstable = TRUE; |
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| 60 | } |
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| 61 | } |
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| 62 | g_strfreev (versions); |
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| 63 | |
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| 64 | return unstable; |
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| 65 | } |
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| 66 | |
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| 67 | void |
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| 68 | gdm_set_fatal_warnings_if_unstable (void) |
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| 69 | { |
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| 70 | if (gdm_is_version_unstable ()) { |
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| 71 | g_setenv ("G_DEBUG", "fatal_criticals", FALSE); |
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| 72 | g_log_set_always_fatal (G_LOG_LEVEL_CRITICAL); |
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| 73 | } |
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| 74 | } |
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| 75 | |
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| 76 | int |
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| 77 | gdm_wait_on_pid (int pid) |
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| 78 | { |
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| 79 | int status; |
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| 80 | |
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| 81 | wait_again: |
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| 82 | errno = 0; |
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| 83 | if (waitpid (pid, &status, 0) < 0) { |
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| 84 | if (errno == EINTR) { |
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| 85 | goto wait_again; |
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| 86 | } else if (errno == ECHILD) { |
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| 87 | ; /* do nothing, child already reaped */ |
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| 88 | } else { |
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| 89 | g_debug ("GdmCommon: waitpid () should not fail"); |
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| 90 | } |
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| 91 | } |
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| 92 | |
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| 93 | g_debug ("GdmCommon: process (pid:%d) done (%s:%d)", |
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| 94 | (int) pid, |
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| 95 | WIFEXITED (status) ? "status" |
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| 96 | : WIFSIGNALED (status) ? "signal" |
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| 97 | : "unknown", |
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| 98 | WIFEXITED (status) ? WEXITSTATUS (status) |
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| 99 | : WIFSIGNALED (status) ? WTERMSIG (status) |
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| 100 | : -1); |
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| 101 | |
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| 102 | return status; |
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| 103 | } |
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| 104 | |
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| 105 | int |
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| 106 | gdm_signal_pid (int pid, |
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| 107 | int signal) |
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| 108 | { |
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| 109 | int status = -1; |
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| 110 | |
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| 111 | /* perhaps block sigchld */ |
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| 112 | g_debug ("GdmCommon: sending signal %d to process %d", signal, pid); |
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| 113 | errno = 0; |
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| 114 | status = kill (pid, signal); |
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| 115 | |
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| 116 | if (status < 0) { |
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| 117 | if (errno == ESRCH) { |
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| 118 | g_warning ("Child process %d was already dead.", |
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| 119 | (int)pid); |
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| 120 | } else { |
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| 121 | g_warning ("Couldn't kill child process %d: %s", |
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| 122 | pid, |
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| 123 | g_strerror (errno)); |
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| 124 | } |
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| 125 | } |
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| 126 | |
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| 127 | /* perhaps unblock sigchld */ |
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| 128 | |
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| 129 | return status; |
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| 130 | } |
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| 131 | |
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| 132 | /* hex conversion adapted from D-Bus */ |
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| 133 | /** |
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| 134 | * Appends a two-character hex digit to a string, where the hex digit |
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| 135 | * has the value of the given byte. |
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| 136 | * |
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| 137 | * @param str the string |
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| 138 | * @param byte the byte |
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| 139 | */ |
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| 140 | static void |
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| 141 | _gdm_string_append_byte_as_hex (GString *str, |
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| 142 | int byte) |
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| 143 | { |
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| 144 | const char hexdigits[16] = { |
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| 145 | '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', |
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| 146 | 'a', 'b', 'c', 'd', 'e', 'f' |
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| 147 | }; |
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| 148 | |
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| 149 | str = g_string_append_c (str, hexdigits[(byte >> 4)]); |
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| 150 | |
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| 151 | str = g_string_append_c (str, hexdigits[(byte & 0x0f)]); |
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| 152 | } |
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| 153 | |
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| 154 | /** |
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| 155 | * Encodes a string in hex, the way MD5 and SHA-1 are usually |
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| 156 | * encoded. (Each byte is two hex digits.) |
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| 157 | * |
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| 158 | * @param source the string to encode |
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| 159 | * @param start byte index to start encoding |
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| 160 | * @param dest string where encoded data should be placed |
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| 161 | * @param insert_at where to place encoded data |
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| 162 | * @returns #TRUE if encoding was successful, #FALSE if no memory etc. |
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| 163 | */ |
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| 164 | gboolean |
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| 165 | gdm_string_hex_encode (const GString *source, |
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| 166 | int start, |
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| 167 | GString *dest, |
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| 168 | int insert_at) |
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| 169 | { |
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| 170 | GString *result; |
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| 171 | const unsigned char *p; |
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| 172 | const unsigned char *end; |
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| 173 | gboolean retval; |
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| 174 | |
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| 175 | g_return_val_if_fail (source != NULL, FALSE); |
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| 176 | g_return_val_if_fail (dest != NULL, FALSE); |
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| 177 | g_return_val_if_fail (source != dest, FALSE); |
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| 178 | g_return_val_if_fail (start >= 0, FALSE); |
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| 179 | g_return_val_if_fail (dest >= 0, FALSE); |
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| 180 | g_assert (start <= source->len); |
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| 181 | |
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| 182 | result = g_string_new (NULL); |
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| 183 | |
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| 184 | retval = FALSE; |
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| 185 | |
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| 186 | p = (const unsigned char*) source->str; |
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| 187 | end = p + source->len; |
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| 188 | p += start; |
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| 189 | |
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| 190 | while (p != end) { |
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| 191 | _gdm_string_append_byte_as_hex (result, *p); |
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| 192 | ++p; |
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| 193 | } |
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| 194 | |
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| 195 | dest = g_string_insert (dest, insert_at, result->str); |
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| 196 | |
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| 197 | retval = TRUE; |
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| 198 | |
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| 199 | g_string_free (result, TRUE); |
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| 200 | |
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| 201 | return retval; |
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| 202 | } |
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| 203 | |
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| 204 | /** |
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| 205 | * Decodes a string from hex encoding. |
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| 206 | * |
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| 207 | * @param source the string to decode |
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| 208 | * @param start byte index to start decode |
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| 209 | * @param end_return return location of the end of the hex data, or #NULL |
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| 210 | * @param dest string where decoded data should be placed |
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| 211 | * @param insert_at where to place decoded data |
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| 212 | * @returns #TRUE if decoding was successful, #FALSE if no memory. |
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| 213 | */ |
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| 214 | gboolean |
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| 215 | gdm_string_hex_decode (const GString *source, |
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| 216 | int start, |
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| 217 | int *end_return, |
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| 218 | GString *dest, |
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| 219 | int insert_at) |
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| 220 | { |
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| 221 | GString *result; |
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| 222 | const unsigned char *p; |
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| 223 | const unsigned char *end; |
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| 224 | gboolean retval; |
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| 225 | gboolean high_bits; |
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| 226 | |
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| 227 | g_return_val_if_fail (source != NULL, FALSE); |
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| 228 | g_return_val_if_fail (dest != NULL, FALSE); |
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| 229 | g_return_val_if_fail (source != dest, FALSE); |
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| 230 | g_return_val_if_fail (start >= 0, FALSE); |
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| 231 | g_return_val_if_fail (dest >= 0, FALSE); |
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| 232 | |
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| 233 | g_assert (start <= source->len); |
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| 234 | |
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| 235 | result = g_string_new (NULL); |
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| 236 | |
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| 237 | retval = FALSE; |
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| 238 | |
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| 239 | high_bits = TRUE; |
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| 240 | p = (const unsigned char*) source->str; |
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| 241 | end = p + source->len; |
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| 242 | p += start; |
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| 243 | |
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| 244 | while (p != end) { |
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| 245 | unsigned int val; |
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| 246 | |
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| 247 | switch (*p) { |
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| 248 | case '0': |
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| 249 | val = 0; |
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| 250 | break; |
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| 251 | case '1': |
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| 252 | val = 1; |
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| 253 | break; |
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| 254 | case '2': |
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| 255 | val = 2; |
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| 256 | break; |
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| 257 | case '3': |
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| 258 | val = 3; |
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| 259 | break; |
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| 260 | case '4': |
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| 261 | val = 4; |
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| 262 | break; |
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| 263 | case '5': |
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| 264 | val = 5; |
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| 265 | break; |
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| 266 | case '6': |
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| 267 | val = 6; |
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| 268 | break; |
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| 269 | case '7': |
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| 270 | val = 7; |
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| 271 | break; |
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| 272 | case '8': |
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| 273 | val = 8; |
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| 274 | break; |
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| 275 | case '9': |
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| 276 | val = 9; |
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| 277 | break; |
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| 278 | case 'a': |
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| 279 | case 'A': |
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| 280 | val = 10; |
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| 281 | break; |
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| 282 | case 'b': |
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| 283 | case 'B': |
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| 284 | val = 11; |
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| 285 | break; |
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| 286 | case 'c': |
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| 287 | case 'C': |
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| 288 | val = 12; |
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| 289 | break; |
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| 290 | case 'd': |
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| 291 | case 'D': |
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| 292 | val = 13; |
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| 293 | break; |
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| 294 | case 'e': |
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| 295 | case 'E': |
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| 296 | val = 14; |
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| 297 | break; |
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| 298 | case 'f': |
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| 299 | case 'F': |
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| 300 | val = 15; |
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| 301 | break; |
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| 302 | default: |
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| 303 | goto done; |
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| 304 | } |
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| 305 | |
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| 306 | if (high_bits) { |
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| 307 | result = g_string_append_c (result, val << 4); |
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| 308 | } else { |
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| 309 | int len; |
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| 310 | unsigned char b; |
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| 311 | |
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| 312 | len = result->len; |
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| 313 | |
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| 314 | b = result->str[len - 1]; |
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| 315 | |
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| 316 | b |= val; |
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| 317 | |
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| 318 | result->str[len - 1] = b; |
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| 319 | } |
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| 320 | |
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| 321 | high_bits = !high_bits; |
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| 322 | |
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| 323 | ++p; |
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| 324 | } |
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| 325 | |
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| 326 | done: |
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| 327 | dest = g_string_insert (dest, insert_at, result->str); |
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| 328 | |
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| 329 | if (end_return) { |
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| 330 | *end_return = p - (const unsigned char*) source->str; |
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| 331 | } |
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| 332 | |
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| 333 | retval = TRUE; |
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| 334 | |
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| 335 | g_string_free (result, TRUE); |
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| 336 | |
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| 337 | return retval; |
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| 338 | } |
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| 339 | |
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| 340 | static gboolean |
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| 341 | _fd_is_character_device (int fd) |
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| 342 | { |
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| 343 | struct stat file_info; |
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| 344 | |
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| 345 | if (fstat (fd, &file_info) < 0) { |
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| 346 | return FALSE; |
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| 347 | } |
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| 348 | |
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| 349 | return S_ISCHR (file_info.st_mode); |
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| 350 | } |
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| 351 | |
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| 352 | static gboolean |
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| 353 | _read_bytes (int fd, |
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| 354 | char *bytes, |
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| 355 | gsize number_of_bytes, |
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| 356 | GError **error) |
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| 357 | { |
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| 358 | size_t bytes_left_to_read; |
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| 359 | size_t total_bytes_read = 0; |
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| 360 | gboolean premature_eof; |
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| 361 | |
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| 362 | bytes_left_to_read = number_of_bytes; |
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| 363 | premature_eof = FALSE; |
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| 364 | do { |
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| 365 | size_t bytes_read = 0; |
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| 366 | |
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| 367 | errno = 0; |
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| 368 | bytes_read = read (fd, ((guchar *) bytes) + total_bytes_read, |
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| 369 | bytes_left_to_read); |
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| 370 | |
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| 371 | if (bytes_read > 0) { |
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| 372 | total_bytes_read += bytes_read; |
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| 373 | bytes_left_to_read -= bytes_read; |
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| 374 | } else if (bytes_read == 0) { |
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| 375 | premature_eof = TRUE; |
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| 376 | break; |
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| 377 | } else if ((errno != EINTR)) { |
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| 378 | break; |
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| 379 | } |
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| 380 | } while (bytes_left_to_read > 0); |
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| 381 | |
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| 382 | if (premature_eof) { |
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| 383 | g_set_error (error, |
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| 384 | G_FILE_ERROR, |
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| 385 | g_file_error_from_errno (ENODATA), |
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| 386 | "%s", g_strerror (ENODATA)); |
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| 387 | |
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| 388 | return FALSE; |
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| 389 | } else if (bytes_left_to_read > 0) { |
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| 390 | g_set_error (error, |
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| 391 | G_FILE_ERROR, |
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| 392 | g_file_error_from_errno (errno), |
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| 393 | "%s", g_strerror (errno)); |
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| 394 | return FALSE; |
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| 395 | } |
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| 396 | |
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| 397 | return TRUE; |
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| 398 | } |
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| 399 | |
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| 400 | /** |
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| 401 | * Pulls a requested number of bytes from /dev/urandom |
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| 402 | * |
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| 403 | * @param size number of bytes to pull |
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| 404 | * @param error error if read fails |
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| 405 | * @returns The requested number of random bytes or #NULL if fail |
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| 406 | */ |
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| 407 | |
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| 408 | char * |
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| 409 | gdm_generate_random_bytes (gsize size, |
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| 410 | GError **error) |
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| 411 | { |
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| 412 | int fd; |
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| 413 | char *bytes; |
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| 414 | GError *read_error; |
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| 415 | |
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| 416 | /* We don't use the g_rand_* glib apis because they don't document |
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| 417 | * how much entropy they are seeded with, and it might be less |
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| 418 | * than the passed in size. |
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| 419 | */ |
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| 420 | |
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| 421 | errno = 0; |
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| 422 | fd = open ("/dev/urandom", O_RDONLY); |
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| 423 | |
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| 424 | if (fd < 0) { |
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| 425 | g_set_error (error, |
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| 426 | G_FILE_ERROR, |
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| 427 | g_file_error_from_errno (errno), |
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| 428 | "%s", g_strerror (errno)); |
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| 429 | close (fd); |
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| 430 | return NULL; |
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| 431 | } |
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| 432 | |
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| 433 | if (!_fd_is_character_device (fd)) { |
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| 434 | g_set_error (error, |
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| 435 | G_FILE_ERROR, |
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| 436 | g_file_error_from_errno (ENODEV), |
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| 437 | _("/dev/urandom is not a character device")); |
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| 438 | close (fd); |
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| 439 | return NULL; |
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| 440 | } |
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| 441 | |
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| 442 | bytes = g_malloc (size); |
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| 443 | read_error = NULL; |
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| 444 | if (!_read_bytes (fd, bytes, size, &read_error)) { |
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| 445 | g_propagate_error (error, read_error); |
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| 446 | g_free (bytes); |
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| 447 | close (fd); |
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| 448 | return NULL; |
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| 449 | } |
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| 450 | |
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| 451 | close (fd); |
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| 452 | return bytes; |
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| 453 | } |
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