3 * A.R. Gordon (andrew.gordon@net-tel.co.uk). All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed for the FreeBSD project
16 * 4. Neither the name of the author nor the names of any co-contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
20 * THIS SOFTWARE IS PROVIDED BY ANDREW GORDON AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * $DragonFly: src/usr.sbin/rpc.statd/file.c,v 1.3 2007/11/25 01:28:24 swildner Exp $
42 #include <sys/types.h>
43 #include <sys/mman.h> /* For mmap() */
49 FileLayout
*status_info
; /* Pointer to the mmap()ed status file */
50 static int status_fd
; /* File descriptor for the open file */
51 static off_t status_file_len
; /* Current on-disc length of file */
53 /* sync_file --------------------------------------------------------------- */
55 Purpose: Packaged call of msync() to flush changes to mmap()ed file
56 Returns: Nothing. Errors to syslog.
62 if (msync((void *)status_info
, 0, 0) < 0)
64 syslog(LOG_ERR
, "msync() failed: %s", strerror(errno
));
68 /* find_host -------------------------------------------------------------- */
70 Purpose: Find the entry in the status file for a given host
71 Returns: Pointer to that entry in the mmap() region, or NULL.
72 Notes: Also creates entries if requested.
73 Failure to create also returns NULL.
77 find_host(char *hostname
, int create
)
80 HostInfo
*spare_slot
= NULL
;
81 HostInfo
*result
= NULL
;
84 for (i
= 0, hp
= status_info
->hosts
; i
< status_info
->noOfHosts
; i
++, hp
++)
86 if (!strncasecmp(hostname
, hp
->hostname
, SM_MAXSTRLEN
))
91 if (!spare_slot
&& !hp
->monList
&& !hp
->notifyReqd
)
95 /* Return if entry found, or if not asked to create one. */
96 if (result
|| !create
) return (result
);
98 /* Now create an entry, using the spare slot if one was found or */
99 /* adding to the end of the list otherwise, extending file if reqd */
103 spare_slot
= &status_info
->hosts
[status_info
->noOfHosts
];
104 desired_size
= ((char*)spare_slot
- (char*)status_info
) + sizeof(HostInfo
);
105 if (desired_size
> status_file_len
)
107 /* Extend file by writing 1 byte of junk at the desired end pos */
108 lseek(status_fd
, desired_size
- 1, SEEK_SET
);
109 i
= write(status_fd
, &i
, 1);
112 syslog(LOG_ERR
, "Unable to extend status file");
115 status_file_len
= desired_size
;
117 status_info
->noOfHosts
++;
120 /* Initialise the spare slot that has been found/created */
121 /* Note that we do not msync(), since the caller is presumed to be */
122 /* about to modify the entry further */
123 memset(spare_slot
, 0, sizeof(HostInfo
));
124 strncpy(spare_slot
->hostname
, hostname
, SM_MAXSTRLEN
);
128 /* init_file -------------------------------------------------------------- */
130 Purpose: Open file, create if necessary, initialise it.
131 Returns: Nothing - exits on error
132 Notes: Called before process becomes daemon, hence logs to
133 stderr rather than syslog.
134 Opens the file, then mmap()s it for ease of access.
135 Also performs initial clean-up of the file, zeroing
136 monitor list pointers, setting the notifyReqd flag in
137 all hosts that had a monitor list, and incrementing
138 the state number to the next even value.
142 init_file(char *filename
)
144 int new_file
= FALSE
;
145 char buf
[HEADER_LEN
];
148 /* try to open existing file - if not present, create one */
149 status_fd
= open(filename
, O_RDWR
);
150 if ((status_fd
< 0) && (errno
== ENOENT
))
152 status_fd
= open(filename
, O_RDWR
| O_CREAT
, 0644);
156 errx(1, "unable to open status file %s", filename
);
158 /* File now open. mmap() it, with a generous size to allow for */
159 /* later growth, where we will extend the file but not re-map it. */
160 status_info
= (FileLayout
*)
161 mmap(NULL
, 0x10000000, PROT_READ
| PROT_WRITE
, MAP_SHARED
, status_fd
, 0);
163 if (status_info
== (FileLayout
*) MAP_FAILED
)
164 warn("unable to mmap() status file");
166 status_file_len
= lseek(status_fd
, 0L, SEEK_END
);
168 /* If the file was not newly created, validate the contents, and if */
169 /* defective, re-create from scratch. */
172 if ((status_file_len
< HEADER_LEN
) || (status_file_len
173 < (HEADER_LEN
+ sizeof(HostInfo
) * status_info
->noOfHosts
)) )
175 warnx("status file is corrupt");
180 /* Initialisation of a new, empty file. */
183 memset(buf
, 0, sizeof(buf
));
184 lseek(status_fd
, 0L, SEEK_SET
);
185 write(status_fd
, buf
, HEADER_LEN
);
186 status_file_len
= HEADER_LEN
;
190 /* Clean-up of existing file - monitored hosts will have a pointer */
191 /* to a list of clients, which refers to memory in the previous */
192 /* incarnation of the program and so are meaningless now. These */
193 /* pointers are zeroed and the fact that the host was previously */
194 /* monitored is recorded by setting the notifyReqd flag, which will */
195 /* in due course cause a SM_NOTIFY to be sent. */
196 /* Note that if we crash twice in quick succession, some hosts may */
197 /* already have notifyReqd set, where we didn't manage to notify */
198 /* them before the second crash occurred. */
199 for (i
= 0; i
< status_info
->noOfHosts
; i
++)
201 HostInfo
*this_host
= &status_info
->hosts
[i
];
203 if (this_host
->monList
)
205 this_host
->notifyReqd
= TRUE
;
206 this_host
->monList
= NULL
;
209 /* Select the next higher even number for the state counter */
210 status_info
->ourState
= (status_info
->ourState
+ 2) & 0xfffffffe;
211 /*???????******/ status_info
->ourState
++;
215 /* xdr_stat_chge ----------------------------------------------------------- */
217 Purpose: XDR-encode structure of type stat_chge
218 Returns: TRUE if successful
219 Notes: This function is missing from librpcsvc, because the
220 sm_inter.x distributed by Sun omits the SM_NOTIFY
221 procedure used between co-operating statd's
225 xdr_stat_chge(XDR
*xdrs
, stat_chge
*objp
)
227 if (!xdr_string(xdrs
, &objp
->mon_name
, SM_MAXSTRLEN
))
231 if (!xdr_int(xdrs
, &objp
->state
))
239 /* notify_one_host --------------------------------------------------------- */
241 Purpose: Perform SM_NOTIFY procedure at specified host
242 Returns: TRUE if success, FALSE if failed.
246 notify_one_host(char *hostname
)
248 struct timeval timeout
= { 20, 0 }; /* 20 secs timeout */
252 char our_hostname
[SM_MAXSTRLEN
+1];
254 gethostname(our_hostname
, sizeof(our_hostname
));
255 our_hostname
[SM_MAXSTRLEN
] = '\0';
256 arg
.mon_name
= our_hostname
;
257 arg
.state
= status_info
->ourState
;
259 if (debug
) syslog (LOG_DEBUG
, "Sending SM_NOTIFY to host %s from %s", hostname
, our_hostname
);
261 cli
= clnt_create(hostname
, SM_PROG
, SM_VERS
, "udp");
264 syslog(LOG_ERR
, "Failed to contact host %s%s", hostname
,
265 clnt_spcreateerror(""));
269 if (clnt_call(cli
, SM_NOTIFY
, (xdrproc_t
)xdr_stat_chge
, &arg
,
270 (xdrproc_t
)xdr_void
, &dummy
, timeout
)
273 syslog(LOG_ERR
, "Failed to contact rpc.statd at host %s", hostname
);
282 /* notify_hosts ------------------------------------------------------------ */
284 Purpose: Send SM_NOTIFY to all hosts marked as requiring it
285 Returns: Nothing, immediately - forks a process to do the work.
286 Notes: Does nothing if there are no monitored hosts.
287 Called after all the initialisation has been done -
296 int work_to_do
= FALSE
;
300 /* First check if there is in fact any work to do. */
301 for (i
= status_info
->noOfHosts
, hp
= status_info
->hosts
; i
; i
--, hp
++)
310 if (!work_to_do
) return; /* No work found */
315 syslog(LOG_ERR
, "Unable to fork notify process - %s", strerror(errno
));
320 /* Here in the child process. We continue until all the hosts marked */
321 /* as requiring notification have been duly notified. */
322 /* If one of the initial attempts fails, we sleep for a while and */
323 /* have another go. This is necessary because when we have crashed, */
324 /* (eg. a power outage) it is quite possible that we won't be able to */
325 /* contact all monitored hosts immediately on restart, either because */
326 /* they crashed too and take longer to come up (in which case the */
327 /* notification isn't really required), or more importantly if some */
328 /* router etc. needed to reach the monitored host has not come back */
329 /* up yet. In this case, we will be a bit late in re-establishing */
330 /* locks (after the grace period) but that is the best we can do. */
331 /* We try 10 times at 5 sec intervals, 10 more times at 1 minute */
332 /* intervals, then 24 more times at hourly intervals, finally */
333 /* giving up altogether if the host hasn't come back to life after */
336 for (attempts
= 0; attempts
< 44; attempts
++)
338 work_to_do
= FALSE
; /* Unless anything fails */
339 for (i
= status_info
->noOfHosts
, hp
= status_info
->hosts
; i
; i
--, hp
++)
343 if (notify_one_host(hp
->hostname
))
345 hp
->notifyReqd
= FALSE
;
348 else work_to_do
= TRUE
;
351 if (!work_to_do
) break;
352 if (attempts
< 10) sleep(5);
353 else if (attempts
< 20) sleep(60);