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 <stdio.h>
20 #include <stdlib.h>
21 #include <string.h>
22 #include <errno.h>
23 #ifdef HAVE_SYS_PRCTL_H
24 #include <sys/prctl.h>
25 #else
26 #define PR_GET_DUMPABLE 3
27 #endif
28 #if (!defined(HAVE_PRCTL) && defined(linux))
29 #include <sys/syscall.h>
30 #endif
31 #ifdef HAVE_SEMAPHORE_H
32 #include <semaphore.h>
33 #endif
34 #if HAVE_UNISTD_H
35 #include <unistd.h>
36 #endif
37 #include <fcntl.h>
38 #if HAVE_SYS_TYPES_H
39 #include <sys/types.h>
40 #endif
41 #include "com_err.h"
42 #include "error_table.h"
43 #include "internal.h"
44
45 #ifdef TLS
46 #define THREAD_LOCAL static TLS
47 #else
48 #define THREAD_LOCAL static
49 #endif
50
51 THREAD_LOCAL char buffer[25];
52
53 struct et_list * _et_list = (struct et_list *) NULL;
54 struct et_list * _et_dynamic_list = (struct et_list *) NULL;
55
56 #ifdef __GNUC__
57 #define COMERR_ATTR(x) __attribute__(x)
58 #else
59 #define COMERR_ATTR(x)
60 #endif
61
62 #ifdef HAVE_SEM_INIT
63 static sem_t _et_lock;
64 static int _et_lock_initialized;
65
setup_et_lock(void)66 static void COMERR_ATTR((constructor)) setup_et_lock(void)
67 {
68 sem_init(&_et_lock, 0, 1);
69 _et_lock_initialized = 1;
70 }
71
fini_et_lock(void)72 static void COMERR_ATTR((destructor)) fini_et_lock(void)
73 {
74 sem_destroy(&_et_lock);
75 _et_lock_initialized = 0;
76 }
77 #endif
78
79
et_list_lock(void)80 int et_list_lock(void)
81 {
82 #ifdef HAVE_SEM_INIT
83 if (!_et_lock_initialized)
84 setup_et_lock();
85 return sem_wait(&_et_lock);
86 #else
87 return 0;
88 #endif
89 }
90
et_list_unlock(void)91 int et_list_unlock(void)
92 {
93 #ifdef HAVE_SEM_INIT
94 if (_et_lock_initialized)
95 return sem_post(&_et_lock);
96 #endif
97 return 0;
98 }
99
error_message(errcode_t code)100 const char * error_message (errcode_t code)
101 {
102 int offset;
103 struct et_list *et;
104 errcode_t table_num;
105 int started = 0;
106 char *cp;
107
108 offset = (int) (code & ((1<<ERRCODE_RANGE)-1));
109 table_num = code - offset;
110 if (!table_num) {
111 #ifdef HAS_SYS_ERRLIST
112 if (offset < sys_nerr)
113 return(sys_errlist[offset]);
114 else
115 goto oops;
116 #else
117 cp = strerror(offset);
118 if (cp)
119 return(cp);
120 else
121 goto oops;
122 #endif
123 }
124 et_list_lock();
125 for (et = _et_list; et; et = et->next) {
126 if ((et->table->base & 0xffffffL) == (table_num & 0xffffffL)) {
127 /* This is the right table */
128 if (et->table->n_msgs <= offset) {
129 break;
130 } else {
131 const char *msg = et->table->msgs[offset];
132 et_list_unlock();
133 return msg;
134 }
135 }
136 }
137 for (et = _et_dynamic_list; et; et = et->next) {
138 if ((et->table->base & 0xffffffL) == (table_num & 0xffffffL)) {
139 /* This is the right table */
140 if (et->table->n_msgs <= offset) {
141 break;
142 } else {
143 const char *msg = et->table->msgs[offset];
144 et_list_unlock();
145 return msg;
146 }
147 }
148 }
149 et_list_unlock();
150 oops:
151 strcpy (buffer, "Unknown code ");
152 if (table_num) {
153 strcat (buffer, error_table_name (table_num));
154 strcat (buffer, " ");
155 }
156 for (cp = buffer; *cp; cp++)
157 ;
158 if (offset >= 100) {
159 *cp++ = '0' + offset / 100;
160 offset %= 100;
161 started++;
162 }
163 if (started || offset >= 10) {
164 *cp++ = '0' + offset / 10;
165 offset %= 10;
166 }
167 *cp++ = '0' + offset;
168 *cp = '\0';
169 return(buffer);
170 }
171
172 /*
173 * This routine will only return a value if the we are not running as
174 * a privileged process.
175 */
safe_getenv(const char * arg)176 static char *safe_getenv(const char *arg)
177 {
178 if ((getuid() != geteuid()) || (getgid() != getegid()))
179 return NULL;
180 #if HAVE_PRCTL
181 if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
182 return NULL;
183 #else
184 #if (defined(linux) && defined(SYS_prctl))
185 if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
186 return NULL;
187 #endif
188 #endif
189
190 #ifdef HAVE___SECURE_GETENV
191 return __secure_getenv(arg);
192 #else
193 return getenv(arg);
194 #endif
195 }
196
197 #define DEBUG_INIT 0x8000
198 #define DEBUG_ADDREMOVE 0x0001
199
200 static int debug_mask = 0;
201 static FILE *debug_f = 0;
202
init_debug(void)203 static void init_debug(void)
204 {
205 char *dstr, *fn, *tmp;
206 int fd, flags;
207
208 if (debug_mask & DEBUG_INIT)
209 return;
210
211 dstr = getenv("COMERR_DEBUG");
212 if (dstr) {
213 debug_mask = strtoul(dstr, &tmp, 0);
214 if (*tmp || errno)
215 debug_mask = 0;
216 }
217
218 debug_mask |= DEBUG_INIT;
219 if (debug_mask == DEBUG_INIT)
220 return;
221
222 fn = safe_getenv("COMERR_DEBUG_FILE");
223 if (fn)
224 debug_f = fopen(fn, "a");
225 if (!debug_f)
226 debug_f = fopen("/dev/tty", "a");
227 if (debug_f) {
228 fd = fileno(debug_f);
229 if (fd >= 0) {
230 flags = fcntl(fd, F_GETFD);
231 if (flags >= 0)
232 fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
233 }
234 } else
235 debug_mask = DEBUG_INIT;
236
237 }
238
239 /*
240 * New interface provided by krb5's com_err library
241 */
add_error_table(const struct error_table * et)242 errcode_t add_error_table(const struct error_table * et)
243 {
244 struct et_list *el;
245
246 if (!(el = (struct et_list *) malloc(sizeof(struct et_list))))
247 return ENOMEM;
248
249 if (et_list_lock() != 0) {
250 free(el);
251 return errno;
252 }
253
254 el->table = et;
255 el->next = _et_dynamic_list;
256 _et_dynamic_list = el;
257
258 init_debug();
259 if (debug_mask & DEBUG_ADDREMOVE)
260 fprintf(debug_f, "add_error_table: %s (0x%p)\n",
261 error_table_name(et->base),
262 (const void *) et);
263
264 et_list_unlock();
265 return 0;
266 }
267
268 /*
269 * New interface provided by krb5's com_err library
270 */
remove_error_table(const struct error_table * et)271 errcode_t remove_error_table(const struct error_table * et)
272 {
273 struct et_list *el;
274 struct et_list *el2 = 0;
275
276 if (et_list_lock() != 0)
277 return ENOENT;
278
279 el = _et_dynamic_list;
280 init_debug();
281 while (el) {
282 if (el->table->base == et->base) {
283 if (el2) /* Not the beginning of the list */
284 el2->next = el->next;
285 else
286 _et_dynamic_list = el->next;
287 (void) free(el);
288 if (debug_mask & DEBUG_ADDREMOVE)
289 fprintf(debug_f,
290 "remove_error_table: %s (0x%p)\n",
291 error_table_name(et->base),
292 (const void *) et);
293 et_list_unlock();
294 return 0;
295 }
296 el2 = el;
297 el = el->next;
298 }
299 if (debug_mask & DEBUG_ADDREMOVE)
300 fprintf(debug_f, "remove_error_table FAILED: %s (0x%p)\n",
301 error_table_name(et->base),
302 (const void *) et);
303 et_list_unlock();
304 return ENOENT;
305 }
306
307 /*
308 * Variant of the interface provided by Heimdal's com_err library
309 */
310 void
add_to_error_table(struct et_list * new_table)311 add_to_error_table(struct et_list *new_table)
312 {
313 add_error_table(new_table->table);
314 }
315