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 #if HAVE_UNISTD_H
32 #include <unistd.h>
33 #endif
34 #if HAVE_SYS_TYPES_H
35 #include <sys/types.h>
36 #endif
37 #include "com_err.h"
38 #include "error_table.h"
39 #include "internal.h"
40
41 #ifdef TLS
42 #define THREAD_LOCAL static TLS
43 #else
44 #define THREAD_LOCAL static
45 #endif
46
47 THREAD_LOCAL char buffer[25];
48
49 struct et_list * _et_list = (struct et_list *) NULL;
50 struct et_list * _et_dynamic_list = (struct et_list *) NULL;
51
52
error_message(errcode_t code)53 const char * error_message (errcode_t code)
54 {
55 int offset;
56 struct et_list *et;
57 errcode_t table_num;
58 int started = 0;
59 char *cp;
60
61 offset = (int) (code & ((1<<ERRCODE_RANGE)-1));
62 table_num = code - offset;
63 if (!table_num) {
64 #ifdef HAS_SYS_ERRLIST
65 if (offset < sys_nerr)
66 return(sys_errlist[offset]);
67 else
68 goto oops;
69 #else
70 cp = strerror(offset);
71 if (cp)
72 return(cp);
73 else
74 goto oops;
75 #endif
76 }
77 for (et = _et_list; et; et = et->next) {
78 if ((et->table->base & 0xffffffL) == (table_num & 0xffffffL)) {
79 /* This is the right table */
80 if (et->table->n_msgs <= offset)
81 goto oops;
82 return(et->table->msgs[offset]);
83 }
84 }
85 for (et = _et_dynamic_list; et; et = et->next) {
86 if ((et->table->base & 0xffffffL) == (table_num & 0xffffffL)) {
87 /* This is the right table */
88 if (et->table->n_msgs <= offset)
89 goto oops;
90 return(et->table->msgs[offset]);
91 }
92 }
93 oops:
94 strcpy (buffer, "Unknown code ");
95 if (table_num) {
96 strcat (buffer, error_table_name (table_num));
97 strcat (buffer, " ");
98 }
99 for (cp = buffer; *cp; cp++)
100 ;
101 if (offset >= 100) {
102 *cp++ = '0' + offset / 100;
103 offset %= 100;
104 started++;
105 }
106 if (started || offset >= 10) {
107 *cp++ = '0' + offset / 10;
108 offset %= 10;
109 }
110 *cp++ = '0' + offset;
111 *cp = '\0';
112 return(buffer);
113 }
114
115 /*
116 * This routine will only return a value if the we are not running as
117 * a privileged process.
118 */
safe_getenv(const char * arg)119 static char *safe_getenv(const char *arg)
120 {
121 if ((getuid() != geteuid()) || (getgid() != getegid()))
122 return NULL;
123 #if HAVE_PRCTL
124 if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
125 return NULL;
126 #else
127 #if (defined(linux) && defined(SYS_prctl))
128 if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
129 return NULL;
130 #endif
131 #endif
132
133 #ifdef HAVE___SECURE_GETENV
134 return __secure_getenv(arg);
135 #else
136 return getenv(arg);
137 #endif
138 }
139
140 #define DEBUG_INIT 0x8000
141 #define DEBUG_ADDREMOVE 0x0001
142
143 static int debug_mask = 0;
144 static FILE *debug_f = 0;
145
init_debug(void)146 static void init_debug(void)
147 {
148 char *dstr;
149 char *fn;
150
151 if (debug_mask & DEBUG_INIT)
152 return;
153
154 dstr = getenv("COMERR_DEBUG");
155 if (dstr)
156 debug_mask = strtoul(dstr, 0, 0);
157
158 fn = safe_getenv("COMERR_DEBUG_FILE");
159 if (fn)
160 debug_f = fopen(fn, "a");
161 if (!debug_f)
162 debug_f = fopen("/dev/tty", "a");
163 if (!debug_f)
164 debug_mask = 0;
165
166 debug_mask |= DEBUG_INIT;
167 }
168
169 /*
170 * New interface provided by krb5's com_err library
171 */
add_error_table(const struct error_table * et)172 errcode_t add_error_table(const struct error_table * et)
173 {
174 struct et_list *el;
175
176 if (!(el = (struct et_list *) malloc(sizeof(struct et_list))))
177 return ENOMEM;
178
179 el->table = et;
180 el->next = _et_dynamic_list;
181 _et_dynamic_list = el;
182
183 init_debug();
184 if (debug_mask & DEBUG_ADDREMOVE)
185 fprintf(debug_f, "add_error_table: %s (0x%p)\n",
186 error_table_name(et->base),
187 (const void *) et);
188
189 return 0;
190 }
191
192 /*
193 * New interface provided by krb5's com_err library
194 */
remove_error_table(const struct error_table * et)195 errcode_t remove_error_table(const struct error_table * et)
196 {
197 struct et_list *el = _et_dynamic_list;
198 struct et_list *el2 = 0;
199
200 init_debug();
201 while (el) {
202 if (el->table->base == et->base) {
203 if (el2) /* Not the beginning of the list */
204 el2->next = el->next;
205 else
206 _et_dynamic_list = el->next;
207 (void) free(el);
208 if (debug_mask & DEBUG_ADDREMOVE)
209 fprintf(debug_f,
210 "remove_error_table: %s (0x%p)\n",
211 error_table_name(et->base),
212 (const void *) et);
213 return 0;
214 }
215 el2 = el;
216 el = el->next;
217 }
218 if (debug_mask & DEBUG_ADDREMOVE)
219 fprintf(debug_f, "remove_error_table FAILED: %s (0x%p)\n",
220 error_table_name(et->base),
221 (const void *) et);
222 return ENOENT;
223 }
224
225 /*
226 * Variant of the interface provided by Heimdal's com_err library
227 */
228 void
add_to_error_table(struct et_list * new_table)229 add_to_error_table(struct et_list *new_table)
230 {
231 add_error_table(new_table->table);
232 }
233