1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
|
/*
* Copyright (c) 1999-2004, 2006 Sendmail, Inc. and its suppliers.
* All rights reserved.
*
* By using this file, you agree to the terms and conditions set
* forth in the LICENSE file which can be found at the top level of
* the sendmail distribution.
*
*/
#include <sm/gen.h>
SM_RCSID("@(#)$Sendmail: signal.c,v 8.44 2006/03/03 03:42:04 ca Exp $")
#include "libmilter.h"
/*
** thread to handle signals
*/
static smutex_t M_Mutex;
static int MilterStop = MILTER_CONT;
static void *mi_signal_thread __P((void *));
static int mi_spawn_signal_thread __P((char *));
/*
** MI_STOP -- return value of MilterStop
**
** Parameters:
** none.
**
** Returns:
** value of MilterStop
*/
int
mi_stop()
{
return MilterStop;
}
/*
** MI_STOP_MILTERS -- set value of MilterStop
**
** Parameters:
** v -- new value for MilterStop.
**
** Returns:
** none.
*/
void
mi_stop_milters(v)
int v;
{
(void) smutex_lock(&M_Mutex);
if (MilterStop < v)
MilterStop = v;
/* close listen socket */
mi_closener();
(void) smutex_unlock(&M_Mutex);
}
/*
** MI_CLEAN_SIGNALS -- clean up signal handler thread
**
** Parameters:
** none.
**
** Returns:
** none.
*/
void
mi_clean_signals()
{
(void) smutex_destroy(&M_Mutex);
}
/*
** MI_SIGNAL_THREAD -- thread to deal with signals
**
** Parameters:
** name -- name of milter
**
** Returns:
** NULL
*/
static void *
mi_signal_thread(name)
void *name;
{
int sig, errs, sigerr;
sigset_t set;
(void) sigemptyset(&set);
(void) sigaddset(&set, SIGHUP);
(void) sigaddset(&set, SIGTERM);
/* Handle Ctrl-C gracefully for debugging */
(void) sigaddset(&set, SIGINT);
errs = 0;
for (;;)
{
sigerr = sig = 0;
#if defined(SOLARIS) || defined(__svr5__)
if ((sig = sigwait(&set)) < 0)
#else /* defined(SOLARIS) || defined(__svr5__) */
if ((sigerr = sigwait(&set, &sig)) != 0)
#endif /* defined(SOLARIS) || defined(__svr5__) */
{
/* some OS return -1 and set errno: copy it */
if (sigerr <= 0)
sigerr = errno;
/* this can happen on OSF/1 (at least) */
if (sigerr == EINTR)
continue;
smi_log(SMI_LOG_ERR,
"%s: sigwait returned error: %d",
(char *)name, sigerr);
if (++errs > MAX_FAILS_T)
{
mi_stop_milters(MILTER_ABRT);
return NULL;
}
continue;
}
errs = 0;
switch (sig)
{
case SIGHUP:
case SIGTERM:
mi_stop_milters(MILTER_STOP);
return NULL;
case SIGINT:
mi_stop_milters(MILTER_ABRT);
return NULL;
default:
smi_log(SMI_LOG_ERR,
"%s: sigwait returned unmasked signal: %d",
(char *)name, sig);
break;
}
}
/* NOTREACHED */
}
/*
** MI_SPAWN_SIGNAL_THREAD -- spawn thread to handle signals
**
** Parameters:
** name -- name of milter
**
** Returns:
** MI_SUCCESS/MI_FAILURE
*/
static int
mi_spawn_signal_thread(name)
char *name;
{
sthread_t tid;
int r;
sigset_t set;
/* Mask HUP and KILL signals */
(void) sigemptyset(&set);
(void) sigaddset(&set, SIGHUP);
(void) sigaddset(&set, SIGTERM);
(void) sigaddset(&set, SIGINT);
if (pthread_sigmask(SIG_BLOCK, &set, NULL) != 0)
{
smi_log(SMI_LOG_ERR,
"%s: Couldn't mask HUP and KILL signals", name);
return MI_FAILURE;
}
r = thread_create(&tid, mi_signal_thread, (void *)name);
if (r != 0)
{
smi_log(SMI_LOG_ERR,
"%s: Couldn't start signal thread: %d",
name, r);
return MI_FAILURE;
}
return MI_SUCCESS;
}
/*
** MI_CONTROL_STARTUP -- startup for thread to handle signals
**
** Parameters:
** name -- name of milter
**
** Returns:
** MI_SUCCESS/MI_FAILURE
*/
int
mi_control_startup(name)
char *name;
{
if (!smutex_init(&M_Mutex))
{
smi_log(SMI_LOG_ERR,
"%s: Couldn't initialize control pipe mutex", name);
return MI_FAILURE;
}
/*
** spawn_signal_thread must happen before other threads are spawned
** off so that it can mask the right signals and other threads
** will inherit that mask.
*/
if (mi_spawn_signal_thread(name) == MI_FAILURE)
{
smi_log(SMI_LOG_ERR,
"%s: Couldn't spawn signal thread", name);
(void) smutex_destroy(&M_Mutex);
return MI_FAILURE;
}
return MI_SUCCESS;
}
|
