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
|
/* omusrmsg.c
* This is the implementation of the build-in output module for sending
* user messages.
*
* File begun on 2007-07-20 by RGerhards (extracted from syslogd.c)
* This file is under development and has not yet arrived at being fully
* self-contained and a real object. So far, it is mostly an excerpt
* of the "old" message code without any modifications. However, it
* helps to have things at the right place one we go to the meat of it.
*
* Copyright 2007 Rainer Gerhards and Adiscon GmbH.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* A copy of the GPL can be found in the file "COPYING" in this distribution.
*/
#include "config.h"
#include "rsyslog.h"
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <signal.h>
#include <sys/param.h>
#include <utmp.h>
#include <unistd.h>
#include <sys/uio.h>
#include <sys/stat.h>
#include <setjmp.h>
#if HAVE_FCNTL_H
#include <fcntl.h>
#else
#include <sys/msgbuf.h>
#endif
#include "srUtils.h"
#include "stringbuf.h"
#include "syslogd-types.h"
#include "syslogd.h"
#include "omusrmsg.h"
jmp_buf ttybuf;
static void endtty()
{
longjmp(ttybuf, 1);
}
/**
* BSD setutent/getutent() replacement routines
* The following routines emulate setutent() and getutent() under
* BSD because they are not available there. We only emulate what we actually
* need! rgerhards 2005-03-18
*/
#ifdef BSD
static FILE *BSD_uf = NULL;
void setutent(void)
{
assert(BSD_uf == NULL);
if ((BSD_uf = fopen(_PATH_UTMP, "r")) == NULL) {
logerror(_PATH_UTMP);
return;
}
}
struct utmp* getutent(void)
{
static struct utmp st_utmp;
if(fread((char *)&st_utmp, sizeof(st_utmp), 1, BSD_uf) != 1)
return NULL;
return(&st_utmp);
}
void endutent(void)
{
fclose(BSD_uf);
BSD_uf = NULL;
}
#endif
/*
* WALLMSG -- Write a message to the world at large
*
* Write the specified message to either the entire
* world, or a list of approved users.
*
* rgerhards, 2005-10-19: applying the following sysklogd patch:
* Tue May 4 16:52:01 CEST 2004: Solar Designer <solar@openwall.com>
* Adjust the size of a variable to prevent a buffer overflow
* should _PATH_DEV ever contain something different than "/dev/".
*/
static void wallmsg(selector_t *f)
{
char p[sizeof(_PATH_DEV) + UNAMESZ];
register int i;
int ttyf;
static int reenter = 0;
struct utmp ut;
struct utmp *uptr;
assert(f != NULL);
if (reenter++)
return;
iovCreate(f); /* init the iovec */
/* open the user login file */
setutent();
/*
* Might as well fork instead of using nonblocking I/O
* and doing notty().
*/
if (fork() == 0) {
signal(SIGTERM, SIG_DFL);
alarm(0);
# ifdef SIGTTOU
signal(SIGTTOU, SIG_IGN);
# endif
sigsetmask(0);
/* TODO: find a way to limit the max size of the message. hint: this
* should go into the template!
*/
/* rgerhards 2005-10-24: HINT: this code might be run in a seperate thread
* instead of a seperate process once we have multithreading...
*/
/* scan the user login file */
while ((uptr = getutent())) {
memcpy(&ut, uptr, sizeof(ut));
/* is this slot used? */
if (ut.ut_name[0] == '\0')
continue;
#ifndef BSD
if (ut.ut_type != USER_PROCESS)
continue;
#endif
if (!(strncmp (ut.ut_name,"LOGIN", 6))) /* paranoia */
continue;
/* should we send the message to this user? */
if (f->f_type == F_USERS) {
for (i = 0; i < MAXUNAMES; i++) {
if (!f->f_un.f_uname[i][0]) {
i = MAXUNAMES;
break;
}
if (strncmp(f->f_un.f_uname[i],
ut.ut_name, UNAMESZ) == 0)
break;
}
if (i >= MAXUNAMES)
continue;
}
/* compute the device name */
strcpy(p, _PATH_DEV);
strncat(p, ut.ut_line, UNAMESZ);
if (setjmp(ttybuf) == 0) {
(void) signal(SIGALRM, endtty);
(void) alarm(15);
/* open the terminal */
ttyf = open(p, O_WRONLY|O_NOCTTY);
if (ttyf >= 0) {
struct stat statb;
if (fstat(ttyf, &statb) == 0 &&
(statb.st_mode & S_IWRITE)) {
(void) writev(ttyf, f->f_iov, f->f_iIovUsed);
}
close(ttyf);
ttyf = -1;
}
}
(void) alarm(0);
}
exit(0); /* "good" exit - this terminates the child forked just for message delivery */
}
/* close the user login file */
endutent();
reenter = 0;
}
/* call the shell action
* returns 0 if it succeeds, something else otherwise
*/
int doActionUsrMsg(selector_t *f)
{
assert(f != NULL);
dprintf("\n");
wallmsg(f);
return 0;
}
/*
* vi:set ai:
*/
|
