summaryrefslogtreecommitdiffstats
path: root/runtime/netstrm.c
blob: bdd2636c15cd416288c1dd8eb4b57df8477edbc7 (plain)
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
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
/* netstrmstrm.c
 * 
 * This class implements a generic netstrmwork stream class. It supports
 * sending and receiving data streams over a netstrmwork. The class abstracts
 * the transport, though it is a safe assumption that TCP is being used.
 * The class has a number of properties, among which are also ones to
 * select privacy settings, eg by enabling TLS and/or GSSAPI. In the 
 * long run, this class shall provide all stream-oriented netstrmwork
 * functionality inside rsyslog.
 *
 * It is a high-level class, which uses a number of helper objects
 * to carry out its work (including, and most importantly, transport
 * drivers).
 *
 * Work on this module begun 2008-04-17 by Rainer Gerhards. This code
 * borrows from librelp's tcp.c/.h code. librelp is dual licensed and
 * Rainer Gerhards and Adiscon GmbH have agreed to permit using the code
 * under the terms of the GNU Lesser General Public License.
 *
 * Copyright 2007, 2008 Rainer Gerhards and Adiscon GmbH.
 *
 * This file is part of the rsyslog runtime library.
 *
 * The rsyslog runtime library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * The rsyslog runtime library 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with the rsyslog runtime library.  If not, see <http://www.gnu.org/licenses/>.
 *
 * A copy of the GPL can be found in the file "COPYING" in this distribution.
 * A copy of the LGPL can be found in the file "COPYING.LESSER" in this distribution.
 */
#include "config.h"

#include "rsyslog.h"
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <assert.h>
#include <errno.h>
#include <string.h>
#include <signal.h>
#include <ctype.h>
#include <netdb.h>
#include <fnmatch.h>
#include <fcntl.h>
#include <unistd.h>

#include "syslogd-types.h"
#include "module-template.h"
#include "parse.h"
#include "srUtils.h"
#include "obj.h"
#include "errmsg.h"
#include "net.h"
#include "nsd.h"
#include "netstrm.h"

MODULE_TYPE_LIB

/* static data */
DEFobjStaticHelpers
DEFobjCurrIf(errmsg)
DEFobjCurrIf(glbl)
DEFobjCurrIf(net)


/* load our low-level driver. This must be done before any
 * driver-specific functions (allmost all...) can be carried
 * out. Note that the driver's .ifIsLoaded is correctly
 * initialized by calloc() and we depend on that.
 * rgerhards, 2008-04-18
 */
static rsRetVal
loadDrvr(netstrm_t *pThis)
{
	uchar *pDrvrName;
	DEFiRet;

	pDrvrName = pThis->pDrvrName;
	if(pDrvrName == NULL) /* if no drvr name is set, use system default */
		pDrvrName = glbl.GetDfltNetstrmDrvr();

	pThis->Drvr.ifVersion = nsdCURR_IF_VERSION;
	/* The pDrvrName+2 below is a hack to obtain the object name. It 
	 * safes us to have yet another variable with the name without "lm" in
	 * front of it. If we change the module load interface, we may re-think
	 * about this hack, but for the time being it is efficient and clean
	 * enough. -- rgerhards, 2008-04-18
	 */
	CHKiRet(obj.UseObj(__FILE__, pDrvrName+2, pDrvrName, (void*) &pThis->Drvr));
finalize_it:
	RETiRet;
}


/* Standard-Constructor */
BEGINobjConstruct(netstrm) /* be sure to specify the object type also in END macro! */
ENDobjConstruct(netstrm)


/* destructor for the netstrm object */
BEGINobjDestruct(netstrm) /* be sure to specify the object type also in END and CODESTART macros! */
CODESTARTobjDestruct(netstrm)
	if(pThis->pDrvrData != NULL)
		iRet = pThis->Drvr.Destruct(&pThis->pDrvrData);
ENDobjDestruct(netstrm)


/* ConstructionFinalizer */
static rsRetVal
netstrmConstructFinalize(netstrm_t *pThis)
{
	DEFiRet;
	ISOBJ_TYPE_assert(pThis, netstrm);
	CHKiRet(loadDrvr(pThis));
	CHKiRet(pThis->Drvr.Construct(&pThis->pDrvrData));
finalize_it:
	RETiRet;
}

/* abort a connection. This is much like Destruct(), but tries
 * to discard any unsent data. -- rgerhards, 2008-03-24
 */
static rsRetVal
AbortDestruct(netstrm_t **ppThis)
{
	DEFiRet;
	assert(ppThis != NULL);
	ISOBJ_TYPE_assert((*ppThis), netstrm);

	/* we do NOT exit on error, because that would make things worse */
	(*ppThis)->Drvr.Abort((*ppThis)->pDrvrData);
	iRet = netstrmDestruct(ppThis);

	RETiRet;
}


/* accept an incoming connection request
 * The netstrm instance that had the incoming request must be provided. If
 * the connection request succeeds, a new netstrm object is created and 
 * passed back to the caller. The caller is responsible for destructing it.
 * pReq is the nsd_t obj that has the accept request.
 * rgerhards, 2008-04-21
 */
static rsRetVal
AcceptConnReq(netstrm_t *pThis, nsd_t *pReqNsd, netstrm_t **ppNew)
{
	netstrm_t *pNew = NULL;
	nsd_t *pNewNsd = NULL;
	DEFiRet;

	ISOBJ_TYPE_assert(pThis, netstrm);
	assert(pReqNsd != NULL);
	assert(ppNew != NULL);

	/* accept the new connection */
	CHKiRet(pThis->Drvr.AcceptConnReq(pReqNsd, &pNewNsd));

	/* construct our object so that we can use it... */
	CHKiRet(netstrmConstruct(&pNew));

	pNew->pDrvrData = pNewNsd;
	if(pThis->pDrvrName == NULL) {
		pNew->pDrvrName = NULL;
	} else {
		CHKmalloc(pNew->pDrvrName = (uchar*) strdup((char*)pThis->pDrvrName));
	}
	CHKiRet(loadDrvr(pNew));

	*ppNew = pNew;

finalize_it:
	if(iRet != RS_RET_OK) {
		if(pNew != NULL)
			netstrmDestruct(&pNew);
		/* the close may be redundant, but that doesn't hurt... */
		if(pNewNsd != NULL)
			pThis->Drvr.Destruct(&pNewNsd);
	}
	RETiRet;
}


/* make the netstrm listen to specified port and IP.
 * pLstnIP points to the port to listen to (NULL means "all"),
 * iMaxSess has the maximum number of sessions permitted (this ist just a hint).
 * pLstnPort must point to a port name or number. NULL is NOT permitted.
 * rgerhards, 2008-04-22
 */
static rsRetVal
LstnInit(netstrm_t *pThis, uchar *pLstnPort, uchar *pLstnIP, int iSessMax)
{
	DEFiRet;
	ISOBJ_TYPE_assert(pThis, netstrm);
	assert(pLstnPort != NULL);
	CHKiRet(pThis->Drvr.LstnInit(&pThis->parrLstn, &pThis->isizeLstnArr, pLstnPort, pLstnIP, iSessMax));

finalize_it:
	RETiRet;
}


/* receive data from a tcp socket
 * The lenBuf parameter must contain the max buffer size on entry and contains
 * the number of octets read (or -1 in case of error) on exit. This function
 * never blocks, not even when called on a blocking socket. That is important
 * for client sockets, which are set to block during send, but should not
 * block when trying to read data. If *pLenBuf is -1, an error occured and
 * errno holds the exact error cause.
 * rgerhards, 2008-03-17
 */
static rsRetVal
Rcv(netstrm_t *pThis, uchar *pBuf, ssize_t *pLenBuf)
{
	DEFiRet;
	ISOBJ_TYPE_assert(pThis, netstrm);
	iRet = pThis->Drvr.Rcv(pThis->pDrvrData, pBuf, pLenBuf);
	RETiRet;
}


/* send a buffer. On entry, pLenBuf contains the number of octets to
 * write. On exit, it contains the number of octets actually written.
 * If this number is lower than on entry, only a partial buffer has
 * been written.
 * rgerhards, 2008-03-19
 */
static rsRetVal
Send(netstrm_t *pThis, uchar *pBuf, ssize_t *pLenBuf)
{
	DEFiRet;
	ISOBJ_TYPE_assert(pThis, netstrm);
	iRet = pThis->Drvr.Send(pThis->pDrvrData, pBuf, pLenBuf);
	RETiRet;
}


/* open a connection to a remote host (server).
 * rgerhards, 2008-03-19
 */
static rsRetVal
Connect(netstrm_t *pThis, int family, uchar *port, uchar *host)
{
	DEFiRet;
	ISOBJ_TYPE_assert(pThis, netstrm);
	assert(port != NULL);
	assert(host != NULL);
	iRet = pThis->Drvr.Connect(pThis->pDrvrData, family, port, host);
	RETiRet;
}


/* queryInterface function
 */
BEGINobjQueryInterface(netstrm)
CODESTARTobjQueryInterface(netstrm)
	if(pIf->ifVersion != netstrmCURR_IF_VERSION) {/* check for current version, increment on each change */
		ABORT_FINALIZE(RS_RET_INTERFACE_NOT_SUPPORTED);
	}

	/* ok, we have the right interface, so let's fill it
	 * Please note that we may also do some backwards-compatibility
	 * work here (if we can support an older interface version - that,
	 * of course, also affects the "if" above).
	 */
	pIf->Construct = netstrmConstruct;
	pIf->ConstructFinalize = netstrmConstructFinalize;
	pIf->Destruct = netstrmDestruct;
	pIf->AbortDestruct = AbortDestruct;
	pIf->Rcv = Rcv;
	pIf->Send = Send;
	pIf->Connect = Connect;
	pIf->LstnInit = LstnInit;
	pIf->AcceptConnReq = AcceptConnReq;
finalize_it:
ENDobjQueryInterface(netstrm)


/* exit our class
 */
BEGINObjClassExit(netstrm, OBJ_IS_LOADABLE_MODULE) /* CHANGE class also in END MACRO! */
CODESTARTObjClassExit(netstrm)
	/* release objects we no longer need */
	objRelease(net, CORE_COMPONENT);
	objRelease(glbl, CORE_COMPONENT);
	objRelease(errmsg, CORE_COMPONENT);
ENDObjClassExit(netstrm)


/* Initialize the netstrm class. Must be called as the very first method
 * before anything else is called inside this class.
 * rgerhards, 2008-02-19
 */
BEGINAbstractObjClassInit(netstrm, 1, OBJ_IS_CORE_MODULE) /* class, version */
	/* request objects we use */
	CHKiRet(objUse(errmsg, CORE_COMPONENT));
	CHKiRet(objUse(glbl, CORE_COMPONENT));
	CHKiRet(objUse(net, CORE_COMPONENT));

	/* set our own handlers */
ENDObjClassInit(netstrm)


/* --------------- here now comes the plumbing that makes as a library module --------------- */


BEGINmodExit
CODESTARTmodExit
	netstrmClassExit();
ENDmodExit


BEGINqueryEtryPt
CODESTARTqueryEtryPt
CODEqueryEtryPt_STD_LIB_QUERIES
ENDqueryEtryPt


BEGINmodInit()
CODESTARTmodInit
	*ipIFVersProvided = CURR_MOD_IF_VERSION; /* we only support the current interface specification */

	/* Initialize all classes that are in our module - this includes ourselfs */
	CHKiRet(netstrmClassInit(pModInfo)); /* must be done after tcps_sess, as we use it */
ENDmodInit
/* vi:set ai:
 */