1 /*
2 * $Header$
3 * $Source$
4 * $Locker$
5 *
6 * Copyright 1987 by the Student Information Processing Board
7 * of the Massachusetts Institute of Technology
8 *
9 * Permission to use, copy, modify, and distribute this software and
10 * its documentation for any purpose is hereby granted, provided that
11 * the names of M.I.T. and the M.I.T. S.I.P.B. not be used in
12 * advertising or publicity pertaining to distribution of the software
13 * without specific, written prior permission. M.I.T. and the
14 * M.I.T. S.I.P.B. make no representations about the suitability of
15 * this software for any purpose. It is provided "as is" without
16 * express or implied warranty.
17 */
18
19 #if HAVE_SECURE_GETENV
20 #define _GNU_SOURCE
21 #endif
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 #include <errno.h>
26 #ifdef HAVE_SYS_PRCTL_H
27 #include <sys/prctl.h>
28 #else
29 #define PR_GET_DUMPABLE 3
30 #endif
31 #if (!defined(HAVE_PRCTL) && defined(linux))
32 #include <sys/syscall.h>
33 #endif
34 #ifdef HAVE_SEMAPHORE_H
35 #include <semaphore.h>
36 #endif
37 #if HAVE_UNISTD_H
38 #include <unistd.h>
39 #endif
40 #include <fcntl.h>
41 #if HAVE_SYS_TYPES_H
42 #include <sys/types.h>
43 #endif
44 #include "com_err.h"
45 #include "error_table.h"
46 #include "internal.h"
47
48 #ifdef TLS
49 #define THREAD_LOCAL static TLS
50 #else
51 #define THREAD_LOCAL static
52 #endif
53
54 THREAD_LOCAL char buffer[25];
55
56 struct et_list * _et_list = (struct et_list *) NULL;
57 struct et_list * _et_dynamic_list = (struct et_list *) NULL;
58
59 #ifdef __GNUC__
60 #define COMERR_ATTR(x) __attribute__(x)
61 #else
62 #define COMERR_ATTR(x)
63 #endif
64
65 #ifdef HAVE_SEM_INIT
66 static sem_t _et_lock;
67 static int _et_lock_initialized;
68
setup_et_lock(void)69 static void COMERR_ATTR((constructor)) setup_et_lock(void)
70 {
71 sem_init(&_et_lock, 0, 1);
72 _et_lock_initialized = 1;
73 }
74
fini_et_lock(void)75 static void COMERR_ATTR((destructor)) fini_et_lock(void)
76 {
77 sem_destroy(&_et_lock);
78 _et_lock_initialized = 0;
79 }
80 #endif
81
82
et_list_lock(void)83 int et_list_lock(void)
84 {
85 #ifdef HAVE_SEM_INIT
86 if (!_et_lock_initialized)
87 setup_et_lock();
88 return sem_wait(&_et_lock);
89 #else
90 return 0;
91 #endif
92 }
93
et_list_unlock(void)94 int et_list_unlock(void)
95 {
96 #ifdef HAVE_SEM_INIT
97 if (_et_lock_initialized)
98 return sem_post(&_et_lock);
99 #endif
100 return 0;
101 }
102
103 typedef char *(*gettextf) (const char *);
104
105 static gettextf com_err_gettext = NULL;
106
set_com_err_gettext(gettextf new_proc)107 gettextf set_com_err_gettext(gettextf new_proc)
108 {
109 gettextf x = com_err_gettext;
110
111 com_err_gettext = new_proc;
112
113 return x;
114 }
115
116
error_message(errcode_t code)117 const char * error_message (errcode_t code)
118 {
119 int offset;
120 struct et_list *et;
121 errcode_t table_num;
122 int started = 0;
123 char *cp;
124
125 offset = (int) (code & ((1<<ERRCODE_RANGE)-1));
126 table_num = code - offset;
127 if (!table_num) {
128 #ifdef HAS_SYS_ERRLIST
129 if (offset < sys_nerr)
130 return(sys_errlist[offset]);
131 else
132 goto oops;
133 #else
134 cp = strerror(offset);
135 if (cp)
136 return(cp);
137 else
138 goto oops;
139 #endif
140 }
141 et_list_lock();
142 for (et = _et_list; et; et = et->next) {
143 if ((et->table->base & 0xffffffL) == (table_num & 0xffffffL)) {
144 /* This is the right table */
145 if (et->table->n_msgs <= offset) {
146 break;
147 } else {
148 const char *msg = et->table->msgs[offset];
149 et_list_unlock();
150 if (com_err_gettext)
151 return (*com_err_gettext)(msg);
152 else
153 return msg;
154 }
155 }
156 }
157 for (et = _et_dynamic_list; et; et = et->next) {
158 if ((et->table->base & 0xffffffL) == (table_num & 0xffffffL)) {
159 /* This is the right table */
160 if (et->table->n_msgs <= offset) {
161 break;
162 } else {
163 const char *msg = et->table->msgs[offset];
164 et_list_unlock();
165 if (com_err_gettext)
166 return (*com_err_gettext)(msg);
167 else
168 return msg;
169 }
170 }
171 }
172 et_list_unlock();
173 oops:
174 strcpy (buffer, "Unknown code ");
175 if (table_num) {
176 strcat (buffer, error_table_name (table_num));
177 strcat (buffer, " ");
178 }
179 for (cp = buffer; *cp; cp++)
180 ;
181 if (offset >= 100) {
182 *cp++ = '0' + offset / 100;
183 offset %= 100;
184 started++;
185 }
186 if (started || offset >= 10) {
187 *cp++ = '0' + offset / 10;
188 offset %= 10;
189 }
190 *cp++ = '0' + offset;
191 *cp = '\0';
192 return(buffer);
193 }
194
195 /*
196 * This routine will only return a value if the we are not running as
197 * a privileged process.
198 */
safe_getenv(const char * arg)199 static char *safe_getenv(const char *arg)
200 {
201 if ((getuid() != geteuid()) || (getgid() != getegid()))
202 return NULL;
203 #if HAVE_PRCTL
204 if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
205 return NULL;
206 #else
207 #if (defined(linux) && defined(SYS_prctl))
208 if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
209 return NULL;
210 #endif
211 #endif
212
213 #if defined(HAVE_SECURE_GETENV)
214 return secure_getenv(arg);
215 #elif defined(HAVE___SECURE_GETENV)
216 return __secure_getenv(arg);
217 #else
218 return getenv(arg);
219 #endif
220 }
221
222 #define DEBUG_INIT 0x8000
223 #define DEBUG_ADDREMOVE 0x0001
224
225 static int debug_mask = 0;
226 static FILE *debug_f = 0;
227
init_debug(void)228 static void init_debug(void)
229 {
230 char *dstr, *fn, *tmp;
231 int fd, flags;
232
233 if (debug_mask & DEBUG_INIT)
234 return;
235
236 dstr = getenv("COMERR_DEBUG");
237 if (dstr) {
238 debug_mask = strtoul(dstr, &tmp, 0);
239 if (*tmp || errno)
240 debug_mask = 0;
241 }
242
243 debug_mask |= DEBUG_INIT;
244 if (debug_mask == DEBUG_INIT)
245 return;
246
247 fn = safe_getenv("COMERR_DEBUG_FILE");
248 if (fn)
249 debug_f = fopen(fn, "a");
250 if (!debug_f)
251 debug_f = fopen("/dev/tty", "a");
252 if (debug_f) {
253 fd = fileno(debug_f);
254 if (fd >= 0) {
255 flags = fcntl(fd, F_GETFD);
256 if (flags >= 0)
257 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
258 }
259 } else
260 debug_mask = DEBUG_INIT;
261
262 }
263
264 /*
265 * New interface provided by krb5's com_err library
266 */
add_error_table(const struct error_table * et)267 errcode_t add_error_table(const struct error_table * et)
268 {
269 struct et_list *el;
270
271 if (!(el = (struct et_list *) malloc(sizeof(struct et_list))))
272 return ENOMEM;
273
274 if (et_list_lock() != 0) {
275 free(el);
276 return errno;
277 }
278
279 el->table = et;
280 el->next = _et_dynamic_list;
281 _et_dynamic_list = el;
282
283 init_debug();
284 if (debug_mask & DEBUG_ADDREMOVE)
285 fprintf(debug_f, "add_error_table: %s (0x%p)\n",
286 error_table_name(et->base),
287 (const void *) et);
288
289 et_list_unlock();
290 return 0;
291 }
292
293 /*
294 * New interface provided by krb5's com_err library
295 */
remove_error_table(const struct error_table * et)296 errcode_t remove_error_table(const struct error_table * et)
297 {
298 struct et_list *el;
299 struct et_list *el2 = 0;
300
301 if (et_list_lock() != 0)
302 return ENOENT;
303
304 el = _et_dynamic_list;
305 init_debug();
306 while (el) {
307 if (el->table->base == et->base) {
308 if (el2) /* Not the beginning of the list */
309 el2->next = el->next;
310 else
311 _et_dynamic_list = el->next;
312 (void) free(el);
313 if (debug_mask & DEBUG_ADDREMOVE)
314 fprintf(debug_f,
315 "remove_error_table: %s (0x%p)\n",
316 error_table_name(et->base),
317 (const void *) et);
318 et_list_unlock();
319 return 0;
320 }
321 el2 = el;
322 el = el->next;
323 }
324 if (debug_mask & DEBUG_ADDREMOVE)
325 fprintf(debug_f, "remove_error_table FAILED: %s (0x%p)\n",
326 error_table_name(et->base),
327 (const void *) et);
328 et_list_unlock();
329 return ENOENT;
330 }
331
332 /*
333 * Variant of the interface provided by Heimdal's com_err library
334 */
335 void
add_to_error_table(struct et_list * new_table)336 add_to_error_table(struct et_list *new_table)
337 {
338 add_error_table(new_table->table);
339 }
340