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 #include "config.h"
20 #include <stdio.h>
21 #include <stdlib.h>
22 #include <string.h>
23 #include <errno.h>
24 #ifdef HAVE_SYS_PRCTL_H
25 #include <sys/prctl.h>
26 #else
27 #define PR_GET_DUMPABLE 3
28 #endif
29 #if (!defined(HAVE_PRCTL) && defined(linux))
30 #include <sys/syscall.h>
31 #endif
32 #ifdef HAVE_SEMAPHORE_H
33 #include <semaphore.h>
34 #endif
35 #if HAVE_UNISTD_H
36 #include <unistd.h>
37 #endif
38 #if HAVE_FCNTL
39 #include <fcntl.h>
40 #endif
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 #ifdef __GNU__
117 #define SYS_ERR_BASE 0x40000000
118 #else
119 #define SYS_ERR_BASE 0
120 #endif
121
error_message(errcode_t code)122 const char * error_message (errcode_t code)
123 {
124 int offset;
125 struct et_list *et;
126 errcode_t table_num;
127 int started = 0;
128 char *cp;
129
130 offset = (int) (code & ((1<<ERRCODE_RANGE)-1));
131 table_num = code - offset;
132 if (table_num == SYS_ERR_BASE) {
133 #ifdef HAS_SYS_ERRLIST
134 if (code < sys_nerr)
135 return(sys_errlist[code]);
136 else
137 goto oops;
138 #else
139 cp = strerror(code);
140 if (cp)
141 return(cp);
142 else
143 goto oops;
144 #endif
145 }
146 et_list_lock();
147 for (et = _et_list; et; et = et->next) {
148 if ((et->table->base & 0xffffffL) == (table_num & 0xffffffL)) {
149 /* This is the right table */
150 if (et->table->n_msgs <= offset) {
151 break;
152 } else {
153 const char *msg = et->table->msgs[offset];
154 et_list_unlock();
155 if (com_err_gettext)
156 return (*com_err_gettext)(msg);
157 else
158 return msg;
159 }
160 }
161 }
162 for (et = _et_dynamic_list; et; et = et->next) {
163 if ((et->table->base & 0xffffffL) == (table_num & 0xffffffL)) {
164 /* This is the right table */
165 if (et->table->n_msgs <= offset) {
166 break;
167 } else {
168 const char *msg = et->table->msgs[offset];
169 et_list_unlock();
170 if (com_err_gettext)
171 return (*com_err_gettext)(msg);
172 else
173 return msg;
174 }
175 }
176 }
177 et_list_unlock();
178 oops:
179 strcpy (buffer, "Unknown code ");
180 if (table_num) {
181 strcat (buffer, error_table_name (table_num));
182 strcat (buffer, " ");
183 }
184 for (cp = buffer; *cp; cp++)
185 ;
186 if (offset >= 100) {
187 *cp++ = '0' + offset / 100;
188 offset %= 100;
189 started++;
190 }
191 if (started || offset >= 10) {
192 *cp++ = '0' + offset / 10;
193 offset %= 10;
194 }
195 *cp++ = '0' + offset;
196 *cp = '\0';
197 return(buffer);
198 }
199
200 /*
201 * This routine will only return a value if the we are not running as
202 * a privileged process.
203 */
safe_getenv(const char * arg)204 static char *safe_getenv(const char *arg)
205 {
206 #if !defined(_WIN32)
207 if ((getuid() != geteuid()) || (getgid() != getegid()))
208 return NULL;
209 #endif
210 #if HAVE_PRCTL
211 if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
212 return NULL;
213 #else
214 #if (defined(linux) && defined(SYS_prctl))
215 if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
216 return NULL;
217 #endif
218 #endif
219
220 #if defined(HAVE_SECURE_GETENV)
221 return secure_getenv(arg);
222 #elif defined(HAVE___SECURE_GETENV)
223 return __secure_getenv(arg);
224 #else
225 return getenv(arg);
226 #endif
227 }
228
229 #define DEBUG_INIT 0x8000
230 #define DEBUG_ADDREMOVE 0x0001
231
232 static int debug_mask = 0;
233 static FILE *debug_f = 0;
234
init_debug(void)235 static void init_debug(void)
236 {
237 char *dstr, *fn, *tmp;
238 int fd, flags;
239
240 if (debug_mask & DEBUG_INIT)
241 return;
242
243 dstr = getenv("COMERR_DEBUG");
244 if (dstr) {
245 debug_mask = strtoul(dstr, &tmp, 0);
246 if (*tmp || errno)
247 debug_mask = 0;
248 }
249
250 debug_mask |= DEBUG_INIT;
251 if (debug_mask == DEBUG_INIT)
252 return;
253
254 fn = safe_getenv("COMERR_DEBUG_FILE");
255 if (fn)
256 debug_f = fopen(fn, "a");
257 if (!debug_f)
258 debug_f = fopen("/dev/tty", "a");
259 if (debug_f) {
260 fd = fileno(debug_f);
261 #if defined(HAVE_FCNTL)
262 if (fd >= 0) {
263 flags = fcntl(fd, F_GETFD);
264 if (flags >= 0)
265 flags = fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
266 if (flags < 0) {
267 fprintf(debug_f, "Couldn't set FD_CLOEXEC "
268 "on debug FILE: %s\n", strerror(errno));
269 fclose(debug_f);
270 debug_f = NULL;
271 debug_mask = DEBUG_INIT;
272 }
273 }
274 #endif
275 } else
276 debug_mask = DEBUG_INIT;
277
278 }
279
280 /*
281 * New interface provided by krb5's com_err library
282 */
add_error_table(const struct error_table * et)283 errcode_t add_error_table(const struct error_table * et)
284 {
285 struct et_list *el;
286
287 if (!(el = (struct et_list *) malloc(sizeof(struct et_list))))
288 return ENOMEM;
289
290 if (et_list_lock() != 0) {
291 free(el);
292 return errno;
293 }
294
295 el->table = et;
296 el->next = _et_dynamic_list;
297 _et_dynamic_list = el;
298
299 init_debug();
300 if (debug_mask & DEBUG_ADDREMOVE)
301 fprintf(debug_f, "add_error_table: %s (0x%p)\n",
302 error_table_name(et->base),
303 (const void *) et);
304
305 et_list_unlock();
306 return 0;
307 }
308
309 /*
310 * New interface provided by krb5's com_err library
311 */
remove_error_table(const struct error_table * et)312 errcode_t remove_error_table(const struct error_table * et)
313 {
314 struct et_list *el;
315 struct et_list *el2 = 0;
316
317 if (et_list_lock() != 0)
318 return ENOENT;
319
320 el = _et_dynamic_list;
321 init_debug();
322 while (el) {
323 if (el->table->base == et->base) {
324 if (el2) /* Not the beginning of the list */
325 el2->next = el->next;
326 else
327 _et_dynamic_list = el->next;
328 (void) free(el);
329 if (debug_mask & DEBUG_ADDREMOVE)
330 fprintf(debug_f,
331 "remove_error_table: %s (0x%p)\n",
332 error_table_name(et->base),
333 (const void *) et);
334 et_list_unlock();
335 return 0;
336 }
337 el2 = el;
338 el = el->next;
339 }
340 if (debug_mask & DEBUG_ADDREMOVE)
341 fprintf(debug_f, "remove_error_table FAILED: %s (0x%p)\n",
342 error_table_name(et->base),
343 (const void *) et);
344 et_list_unlock();
345 return ENOENT;
346 }
347
348 /*
349 * Variant of the interface provided by Heimdal's com_err library
350 */
351 void
add_to_error_table(struct et_list * new_table)352 add_to_error_table(struct et_list *new_table)
353 {
354 add_error_table(new_table->table);
355 }
356