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
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
|
/*
* The Unix Channel
*
* by Michel Beaudouin-Lafon
*
* Copyright 1990-1993
* Laboratoire de Recherche en Informatique (LRI)
*
* Port server: client side
*
* $Id$
* $CurLog$
*/
#include "PortServer.h"
#include "PortServerReq.h"
#include "error.h"
#include "Datagram.h"
#include "ccu/Timer.h"
#include <stdlib.h>
#include <string.h>
// sometimes, cuserid is declared in stdio.h ...
#include <stdio.h>
#ifdef __osf__
extern "C" {
#endif
#include <netdb.h>
#ifdef __osf__
}
#endif
#ifdef __osf__
extern "C" {
unsigned short htons (unsigned short);
unsigned short ntohs (unsigned short);
int gethostname (char*, int);
}
#endif
#define DEFKEY "%s:"
// *** horrible patch
bool PortServerInquireSysError = false;
/*?class UchPortServer
The class \typ{UchPortServer} described here implements the communication with the port server.
Both servers and clients need to use this class.
The server registers its address with a well-known key in the port server,
while a client uses that key to retrieve the server's address.
?*/
/*?
Construct a link to the port server, given a service name and a host name.
The service name must be present in the service database
(usually the file \com{/etc/services} or a yellow pages map).
The host name identifies the machine on which the port server lives.
If it is the null pointer, the loopback host is assumed.
?*/
UchPortServer :: UchPortServer (const char* serv, const char* host)
: Name ()
{
/* get service name */
struct servent* service = getservbyname (serv, 0);
sword portno;
if (service) {
portno = ntohs (service->s_port);
} else {
const char* port = getenv (serv);
if (port)
portno = atoi (port);
else
portno = 3003;
// ::Error (ErrFatal, "getservbyname", "service not available");
}
/* open datagram socket */
if (host)
Serv = new UchDatagram (0, new UchInetAddress (host, portno));
else
Serv = new UchDatagram (0, new UchInetAddress (LOOPBACK, portno));
if (!Serv->Setup ())
SysError (ErrFatal, "Setup");
Name = serv;
}
/*?nodoc?*/
UchPortServer :: ~UchPortServer ()
{
delete Serv;
Serv = 0;
}
static void
SendRequest (UchDatagram* to, UchPortServerReq req)
{
UchMsgBuffer buf (256);
buf.WriteMsg (req);
to->Write (buf);
}
/*?
Register a server address in the port server.
The actual key that is stored in the port server is computed by \fun{MakeKey(key)}.
This function is to be used by servers that want to register themselves.
If the host field of \var{addr} is \var{LOOPBACK} or \var{ANYADDR}, the actual host id
is registered instead. This makes it possible to retrieve a valid address from another host.
\var{id} is used as an identication key when the server asks to be removed.
If it is 0, the process number of the server (\fun{getpid()}) is used.
?*/
void
UchPortServer :: Register (const char* key, UchInetAddress& addr, int id)
{
long host = addr.Host ();
if (host == LOOPBACK || host == ANYADDR)
host = UchInetAddress::LoopBack ();
if (! id)
id = getpid ();
UchPortServerReq req (PortServRegister, host, addr.Port (), id, MakeKey (key));
SendRequest (Serv, req);
}
/*?
Remove a registered service from the port server.
This function should be called by a server when it exits.
\var{id} authenticates the server so that any other process is unlikely
to be able to remove the service.
If it is 0, the process number of the server (\fun{getpid()}) is used.
If a server fails to remove itself, the association will stay forever in the port server,
unless it is overwritten by the registration of the same key.
?*/
void
UchPortServer :: Remove (const char* key, UchInetAddress& addr, int id)
{
long host = addr.Host ();
if (host == LOOPBACK || host == ANYADDR)
host = UchInetAddress :: LoopBack ();
if (! id)
id = getpid ();
UchPortServerReq req (PortServRemove, host, addr.Port (), id, MakeKey (key));
SendRequest (Serv, req);
}
static bool expired = false;
static void
Expire (Millisecond)
{
expired = true;
}
/*?
Get a server address from the port server.
Wait for \var{timeout} seconds before giving up:
the port server may not respond because it is not present (the communication uses datagrams).
0 is returned if the function failed (because of the timeout or because
the given key is not registered);
else a newly allocated address is returned.
If the host field of the retrieved address is the same as the host id,
it is replaced by the loopback host.
This function is to be used by clients to retrieve the address of the server they want to connect to.
?*/
UchInetAddress*
UchPortServer :: Inquire (const char* key, int timeout)
{
// *** horrible patch
PortServerInquireSysError = false;
UchPortServerReq req (PortServInquire, 0, 0, 0, MakeKey (key));
SendRequest (Serv, req);
UchMsgBuffer buf (256);
expired = false;
CcuTimer timer (timeout * 1000, Expire);
int n = Serv->Receive (buf);
if (expired) {
::Error (ErrWarn, "UchPortServer::Inquire", "timeout");
return 0;
}
if (n <= 0) {
SysError (ErrWarn, "Inquire");
// *** horrible patch
PortServerInquireSysError = true;
return 0;
}
if (! buf.ReadMsg (req)) {
::Error (ErrWarn, "UchPortServer::Inquire", "could not read answer");
return 0;
}
switch (req.Type) {
case PortServAnswer :
return new UchInetAddress (req.Host == UchInetAddress::LoopBack () ? LOOPBACK : req.Host, req.Port);
case PortServFail :
return 0;
}
::Error (ErrWarn, "UchPortServer::Inquire", "unexpected answer type");
return 0;
}
/*?
Retrieve all entries in the port server that match a given key.
The key is a regular expression in the form of \com{ed(1)}.
For each match, the function \fun{f} is called with four arguments:
the matched string, its associated host and port numbers, and the original key.
If it returns 0, \fun{Match} returns immediately.
The type \typ{^{PortServMatchFun}} is declared like this:\\
\com{typedef int (* PortServMatchFun) (const char*, lword, sword, const char*)}\\
\fun{Match} waits for \var{timeout} seconds before giving up while waiting an answer:
the port server may not respond because it is not present (the communication uses datagrams).
The function returns the total number of expected answers (it can be 0), or -1 if an error occurs.
?*/
int
UchPortServer :: Match (const char* key, PortServMatchFun f, int timeout)
{
int nb = 0;
int call = 1;
UchPortServerReq req (PortServMatch, 0, 0, 0, key);
SendRequest (Serv, req);
UchMsgBuffer buf (1024);
for (;;) {
buf.Flush ();
expired = false;
CcuTimer timer (timeout * 1000, Expire);
int n = Serv->Receive (buf);
if (expired) {
::Error (ErrWarn, "UchPortServer::Match", "timeout");
return 0;
}
if (n <= 0) {
SysError (ErrWarn, "Match");
break;
}
if (! buf.ReadMsg (req)) {
::Error (ErrWarn, "Match", "could not read message");
continue;
}
switch (req.Type) {
case PortServMatch:
if (call)
call = f (req.Key, req.Host, req.Port, key);
nb++;
break;
case PortServEndMatch:
if (nb != req.Ident)
::Error (ErrWarn, "Match", "lost answers");
return req.Ident;
default:
::Error (ErrWarn, "Match", "unexpected answer type");
return -1;
}
}
return nb;
}
/*?
Ask the port server to dump its state.
This is not normally used unless for debugging.
Note that this is different from the save feature of the port server.
\fun{Dump} uses a different formats, and always uses the standard output of the port server.
?*/
void
UchPortServer :: Dump ()
{
UchPortServerReq req (PortServDump);
SendRequest (Serv, req);
}
/*?
Ask the port server to quit.
If the port server was configured to save its state, it does so before exiting.
NOTE: because the state cannot be reloaded from a file, this function
is dangerous: it makes the port server loose its associations.
?*/
void
UchPortServer :: Quit ()
{
UchPortServerReq req (PortServQuit);
SendRequest (Serv, req);
}
/*?
Build the actual key that will be stored in the port server.
The key is made of a set of components normally separated by colons.
Each component can be a literal string or a meta-character:
\com{\%h} for hostname, \com{\%s} for service name, \com{\%u} for user name.
A sample key is ``\com{\%s:\%u:foo}''.
\com{\%u} and \com{\%h} are useful when a given service needs a different server,
and thus a different association in the port server,
for different users and/or hosts.
\com{\%s} is useful if the same port server is used for different services.
?*/
char*
UchPortServer :: MakeKey (const char* key)
{
static char buffer [256];
char* p = buffer;
for (const char* q = key; *q; q++) {
if (*q == '%') {
switch (*++q) {
case 'h' :
if (gethostname (p, sizeof (buffer) - (p - buffer)) < 0) {
SysError (ErrWarn, "UchPortServer::MakeKey");
strcpy (p, "???");
}
break;
case 'u' : {
char* l = getlogin ();
if (! l)
l = cuserid (0);
if (! l) {
::Error (ErrWarn, "UchPortServer::MakeKey", "getlogin failed");
strcpy (p, "???");
}
strcpy (p, l);
}
break;
case 's' :
strcpy (p, Name);
break;
default :
*p++ = '%';
*p++ = *q;
*p = 0;
break;
}
p += strlen (p);
} else
*p++ = *q;
}
*p = 0;
return buffer;
}
#ifdef DOC
/*?nextdoc?*/
void
PortServerRegister (const char* service, const char* name, UchAddress* addr)
{ }
#endif /* DOC */
/*?
This global function can be used for simple registration to the portserver.
The key used is ``\com{\%s:\%u:name}'', and the default identifier is the process number.
It connects to the local port server.
This function is overloaded for an easy use with \fun{UchAddress::GetAddr}
because it returns an \typ{UchAddress*}.
Be sure however that the address is an internet address (and not a Unix address for instance).
?*/
void
PortServerRegister (const char* service, const char* name, UchInetAddress& addr)
{
#if 0
UchPortServer ps (service);
#else
UchPortServer ps ("agentman");
#endif
char key [256];
#if 0
strcpy (key, DEFKEY);
#else
strcpy (key, service);
strcpy (key, name);
#endif
strcat (key, name);
ps.Register (key, addr, getpid ());
}
#ifdef DOC
/*?nextdoc?*/
void
PortServerRemove (const char* service, const char* name, UchAddress* addr)
{
}
#endif /* DOC */
/*?
This global function can be used for a simple removal from the portserver.
The key used is ``\com{\%s:\%u:name}'', and the default identifier is the process number.
It connects to the local port server.
This function is overloaded for an easy use with \fun{UchAddress::GetAddr}
because it returns an \typ{UchAddress*}.
Be sure however that the address is an internet address (and not a Unix address for instance).
?*/
void
PortServerRemove (const char* service, const char* name, UchInetAddress& addr)
{
#if 0
UchPortServer ps (service);
#else
UchPortServer ps ("agentman");
#endif
char key [256];
#if 0
strcpy (key, DEFKEY);
#else
strcpy (key, service);
strcpy (key, name);
#endif
strcat (key, name);
ps.Remove (key, addr, getpid ());
}
/*?
This global function can be used for a simple inquiry to the portserver.
The key used is ``\com{\%s:\%u:name}''.
It connects to the port server on the given host (default is local).
?*/
UchInetAddress*
PortServerInquire (const char* service, const char* name, const char* host)
{
#if 1
UchPortServer ps (service, (host && *host) ? host : 0);
#else
UchPortServer ps ("agentman", (host && *host) ? host : 0);
#endif
char key [256];
#if 0
strcpy (key, DEFKEY);
#else
strcpy (key, service);
strcpy (key, name);
#endif
strcat (key, name);
return ps.Inquire (key);
}
|