summaryrefslogtreecommitdiffstats
path: root/source3/smbd/connection.c
blob: af74e40f6a5608ed69a5a6a244cdbbef90fe5eff (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
/* 
   Unix SMB/Netbios implementation.
   Version 1.9.
   connection claim routines
   Copyright (C) Andrew Tridgell 1998
   
   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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"


extern fstring remote_machine;

extern int DEBUGLEVEL;

/****************************************************************************
simple routines to do connection counting
****************************************************************************/
BOOL yield_connection(connection_struct *conn,char *name,int max_connections)
{
	struct connect_record crec;
	pstring fname;
	int fd;
	int mypid = getpid();
	int i;

	DEBUG(3,("Yielding connection to %s\n",name));

	if (max_connections <= 0)
		return(True);

	bzero(&crec,sizeof(crec));

	pstrcpy(fname,lp_lockdir());
	trim_string(fname,"","/");

	pstrcat(fname,"/");
	pstrcat(fname,name);
	pstrcat(fname,".LCK");

	fd = open(fname,O_RDWR);
	if (fd == -1) {
		DEBUG(2,("Couldn't open lock file %s (%s)\n",fname,strerror(errno)));
		return(False);
	}

	if (fcntl_lock(fd,SMB_F_SETLKW,0,1,F_WRLCK)==False) {
		DEBUG(0,("ERROR: can't get lock on %s\n", fname));
		return False;
	}

	/* find the right spot */
	for (i=0;i<max_connections;i++) {
		if (read(fd, &crec,sizeof(crec)) != sizeof(crec)) {
			DEBUG(2,("Entry not found in lock file %s\n",fname));
			if (fcntl_lock(fd,SMB_F_SETLKW,0,1,F_UNLCK)==False) {
				DEBUG(0,("ERROR: can't release lock on %s\n", fname));
			}
			close(fd);
			return(False);
		}
		if (crec.pid == mypid && crec.cnum == conn->cnum)
			break;
	}

	if (crec.pid != mypid || crec.cnum != conn->cnum) {
		if (fcntl_lock(fd,SMB_F_SETLKW,0,1,F_UNLCK)==False) {
			DEBUG(0,("ERROR: can't release lock on %s\n", fname));
		}
		close(fd);
		DEBUG(2,("Entry not found in lock file %s\n",fname));
		return(False);
	}

	bzero((void *)&crec,sizeof(crec));
  
	/* remove our mark */
	if (sys_lseek(fd,i*sizeof(crec),SEEK_SET) != i*sizeof(crec) ||
	    write(fd, &crec,sizeof(crec)) != sizeof(crec)) {
		DEBUG(2,("Couldn't update lock file %s (%s)\n",fname,strerror(errno)));
		if (fcntl_lock(fd,SMB_F_SETLKW,0,1,F_UNLCK)==False) {
			DEBUG(0,("ERROR: can't release lock on %s\n", fname));
		}
		close(fd);
		return(False);
	}

	if (fcntl_lock(fd,SMB_F_SETLKW,0,1,F_UNLCK)==False) {
		DEBUG(0,("ERROR: can't release lock on %s\n", fname));
	}

	DEBUG(3,("Yield successful\n"));

	close(fd);
	return(True);
}


/****************************************************************************
simple routines to do connection counting
****************************************************************************/
BOOL claim_connection(connection_struct *conn,char *name,int max_connections,BOOL Clear)
{
	extern int Client;
	struct connect_record crec;
	pstring fname;
	int fd=-1;
	int i,foundi= -1;
	int total_recs;
	
	if (max_connections <= 0)
		return(True);
	
	DEBUG(5,("trying claim %s %s %d\n",lp_lockdir(),name,max_connections));
	
	pstrcpy(fname,lp_lockdir());
	trim_string(fname,"","/");
	
	if (!directory_exist(fname,NULL))
		mkdir(fname,0755);
	
	pstrcat(fname,"/");
	pstrcat(fname,name);
	pstrcat(fname,".LCK");
	
	if (!file_exist(fname,NULL)) {
		fd = open(fname,O_RDWR|O_CREAT|O_EXCL, 0644);
	}

	if (fd == -1) {
		fd = open(fname,O_RDWR);
	}
	
	if (fd == -1) {
		DEBUG(1,("couldn't open lock file %s\n",fname));
		return(False);
	}

	if (fcntl_lock(fd,SMB_F_SETLKW,0,1,F_WRLCK)==False) {
		DEBUG(0,("ERROR: can't get lock on %s\n", fname));
		return False;
	}

	total_recs = file_size(fname) / sizeof(crec);
			
	/* find a free spot */
	for (i=0;i<max_connections;i++) {
		if (i>=total_recs || 
		    sys_lseek(fd,i*sizeof(crec),SEEK_SET) != i*sizeof(crec) ||
		    read(fd,&crec,sizeof(crec)) != sizeof(crec)) {
			if (foundi < 0) foundi = i;
			break;
		}
		
		if (Clear && crec.pid && !process_exists(crec.pid)) {
			if(sys_lseek(fd,i*sizeof(crec),SEEK_SET) != i*sizeof(crec)) {
              DEBUG(0,("claim_connection: ERROR: sys_lseek failed to seek \
to %d\n", i*sizeof(crec) ));
              continue;
            }
			bzero((void *)&crec,sizeof(crec));
			write(fd, &crec,sizeof(crec));
			if (foundi < 0) foundi = i;
			continue;
		}
		if (foundi < 0 && (!crec.pid || !process_exists(crec.pid))) {
			foundi=i;
			if (!Clear) break;
		}
	}  
	
	if (foundi < 0) {
		DEBUG(3,("no free locks in %s\n",fname));
		if (fcntl_lock(fd,SMB_F_SETLKW,0,1,F_UNLCK)==False) {
			DEBUG(0,("ERROR: can't release lock on %s\n", fname));
		}
		close(fd);
		return(False);
	}      
	
	/* fill in the crec */
	bzero((void *)&crec,sizeof(crec));
	crec.magic = 0x280267;
	crec.pid = getpid();
	if (conn) {
		crec.cnum = conn->cnum;
		crec.uid = conn->uid;
		crec.gid = conn->gid;
		StrnCpy(crec.name,
			lp_servicename(SNUM(conn)),sizeof(crec.name)-1);
	} else {
		crec.cnum = -1;
	}
	crec.start = time(NULL);
	
	StrnCpy(crec.machine,remote_machine,sizeof(crec.machine)-1);
	StrnCpy(crec.addr,client_addr(Client),sizeof(crec.addr)-1);
	
	/* make our mark */
	if (sys_lseek(fd,foundi*sizeof(crec),SEEK_SET) != foundi*sizeof(crec) ||
	    write(fd, &crec,sizeof(crec)) != sizeof(crec)) {
		if (fcntl_lock(fd,SMB_F_SETLKW,0,1,F_UNLCK)==False) {
			DEBUG(0,("ERROR: can't release lock on %s\n", fname));
		}
		close(fd);
		return(False);
	}

	if (fcntl_lock(fd,SMB_F_SETLKW,0,1,F_UNLCK)==False) {
		DEBUG(0,("ERROR: can't release lock on %s\n", fname));
	}
	
	close(fd);
	return(True);
}