| Current Path : /usr/src/usr.sbin/rpc.statd/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //usr/src/usr.sbin/rpc.statd/file.c |
/*
* Copyright (c) 1995
* A.R. Gordon (andrew.gordon@net-tel.co.uk). All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed for the FreeBSD project
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY ANDREW GORDON AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD: release/9.1.0/usr.sbin/rpc.statd/file.c 180025 2008-06-26 10:21:54Z dfr $
*
*/
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/mman.h> /* For mmap() */
#include <rpc/rpc.h>
#include <syslog.h>
#include <stdlib.h>
#include "statd.h"
FileLayout *status_info; /* Pointer to the mmap()ed status file */
static int status_fd; /* File descriptor for the open file */
static off_t status_file_len; /* Current on-disc length of file */
/* sync_file --------------------------------------------------------------- */
/*
Purpose: Packaged call of msync() to flush changes to mmap()ed file
Returns: Nothing. Errors to syslog.
*/
void sync_file(void)
{
if (msync((void *)status_info, 0, 0) < 0)
{
syslog(LOG_ERR, "msync() failed: %s", strerror(errno));
}
}
/* find_host -------------------------------------------------------------- */
/*
Purpose: Find the entry in the status file for a given host
Returns: Pointer to that entry in the mmap() region, or NULL.
Notes: Also creates entries if requested.
Failure to create also returns NULL.
*/
HostInfo *find_host(char *hostname, int create)
{
HostInfo *hp;
HostInfo *spare_slot = NULL;
HostInfo *result = NULL;
struct addrinfo *ai1, *ai2;
int i;
if (getaddrinfo(hostname, NULL, NULL, &ai1) != 0)
ai1 = NULL;
for (i = 0, hp = status_info->hosts; i < status_info->noOfHosts; i++, hp++)
{
if (!strncasecmp(hostname, hp->hostname, SM_MAXSTRLEN))
{
result = hp;
break;
}
if (hp->hostname[0] &&
getaddrinfo(hp->hostname, NULL, NULL, &ai2) != 0)
ai2 = NULL;
if (ai1 && ai2)
{
struct addrinfo *p1, *p2;
for (p1 = ai1; !result && p1; p1 = p1->ai_next)
{
for (p2 = ai2; !result && p2; p2 = p2->ai_next)
{
if (p1->ai_family == p2->ai_family
&& p1->ai_addrlen == p2->ai_addrlen
&& !memcmp(p1->ai_addr, p2->ai_addr, p1->ai_addrlen))
{
result = hp;
break;
}
}
}
if (result)
break;
}
if (ai2)
freeaddrinfo(ai2);
if (!spare_slot && !hp->monList && !hp->notifyReqd)
spare_slot = hp;
}
if (ai1)
freeaddrinfo(ai1);
/* Return if entry found, or if not asked to create one. */
if (result || !create) return (result);
/* Now create an entry, using the spare slot if one was found or */
/* adding to the end of the list otherwise, extending file if reqd */
if (!spare_slot)
{
off_t desired_size;
spare_slot = &status_info->hosts[status_info->noOfHosts];
desired_size = ((char*)spare_slot - (char*)status_info) + sizeof(HostInfo);
if (desired_size > status_file_len)
{
/* Extend file by writing 1 byte of junk at the desired end pos */
lseek(status_fd, desired_size - 1, SEEK_SET);
i = write(status_fd, &i, 1);
if (i < 1)
{
syslog(LOG_ERR, "Unable to extend status file");
return (NULL);
}
status_file_len = desired_size;
}
status_info->noOfHosts++;
}
/* Initialise the spare slot that has been found/created */
/* Note that we do not msync(), since the caller is presumed to be */
/* about to modify the entry further */
memset(spare_slot, 0, sizeof(HostInfo));
strncpy(spare_slot->hostname, hostname, SM_MAXSTRLEN);
return (spare_slot);
}
/* init_file -------------------------------------------------------------- */
/*
Purpose: Open file, create if necessary, initialise it.
Returns: Nothing - exits on error
Notes: Called before process becomes daemon, hence logs to
stderr rather than syslog.
Opens the file, then mmap()s it for ease of access.
Also performs initial clean-up of the file, zeroing
monitor list pointers, setting the notifyReqd flag in
all hosts that had a monitor list, and incrementing
the state number to the next even value.
*/
void init_file(const char *filename)
{
int new_file = FALSE;
char buf[HEADER_LEN];
int i;
/* try to open existing file - if not present, create one */
status_fd = open(filename, O_RDWR);
if ((status_fd < 0) && (errno == ENOENT))
{
status_fd = open(filename, O_RDWR | O_CREAT, 0644);
new_file = TRUE;
}
if (status_fd < 0)
errx(1, "unable to open status file %s", filename);
/* File now open. mmap() it, with a generous size to allow for */
/* later growth, where we will extend the file but not re-map it. */
status_info = (FileLayout *)
mmap(NULL, 0x10000000, PROT_READ | PROT_WRITE, MAP_SHARED, status_fd, 0);
if (status_info == (FileLayout *) MAP_FAILED)
err(1, "unable to mmap() status file");
status_file_len = lseek(status_fd, 0L, SEEK_END);
/* If the file was not newly created, validate the contents, and if */
/* defective, re-create from scratch. */
if (!new_file)
{
if ((status_file_len < HEADER_LEN) || (status_file_len
< (HEADER_LEN + sizeof(HostInfo) * status_info->noOfHosts)) )
{
warnx("status file is corrupt");
new_file = TRUE;
}
}
/* Initialisation of a new, empty file. */
if (new_file)
{
memset(buf, 0, sizeof(buf));
lseek(status_fd, 0L, SEEK_SET);
write(status_fd, buf, HEADER_LEN);
status_file_len = HEADER_LEN;
}
else
{
/* Clean-up of existing file - monitored hosts will have a pointer */
/* to a list of clients, which refers to memory in the previous */
/* incarnation of the program and so are meaningless now. These */
/* pointers are zeroed and the fact that the host was previously */
/* monitored is recorded by setting the notifyReqd flag, which will */
/* in due course cause a SM_NOTIFY to be sent. */
/* Note that if we crash twice in quick succession, some hosts may */
/* already have notifyReqd set, where we didn't manage to notify */
/* them before the second crash occurred. */
for (i = 0; i < status_info->noOfHosts; i++)
{
HostInfo *this_host = &status_info->hosts[i];
if (this_host->monList)
{
this_host->notifyReqd = TRUE;
this_host->monList = NULL;
}
}
/* Select the next higher even number for the state counter */
status_info->ourState = (status_info->ourState + 2) & 0xfffffffe;
/*???????******/ status_info->ourState++;
}
}
/* notify_one_host --------------------------------------------------------- */
/*
Purpose: Perform SM_NOTIFY procedure at specified host
Returns: TRUE if success, FALSE if failed.
*/
static int notify_one_host(char *hostname)
{
struct timeval timeout = { 20, 0 }; /* 20 secs timeout */
CLIENT *cli;
char dummy;
stat_chge arg;
char our_hostname[SM_MAXSTRLEN+1];
gethostname(our_hostname, sizeof(our_hostname));
our_hostname[SM_MAXSTRLEN] = '\0';
arg.mon_name = our_hostname;
arg.state = status_info->ourState;
if (debug) syslog (LOG_DEBUG, "Sending SM_NOTIFY to host %s from %s", hostname, our_hostname);
cli = clnt_create(hostname, SM_PROG, SM_VERS, "udp");
if (!cli)
{
syslog(LOG_ERR, "Failed to contact host %s%s", hostname,
clnt_spcreateerror(""));
return (FALSE);
}
if (clnt_call(cli, SM_NOTIFY, (xdrproc_t)xdr_stat_chge, &arg,
(xdrproc_t)xdr_void, &dummy, timeout)
!= RPC_SUCCESS)
{
syslog(LOG_ERR, "Failed to contact rpc.statd at host %s", hostname);
clnt_destroy(cli);
return (FALSE);
}
clnt_destroy(cli);
return (TRUE);
}
/* notify_hosts ------------------------------------------------------------ */
/*
Purpose: Send SM_NOTIFY to all hosts marked as requiring it
Returns: Nothing, immediately - forks a process to do the work.
Notes: Does nothing if there are no monitored hosts.
Called after all the initialisation has been done -
logs to syslog.
*/
void notify_hosts(void)
{
int i;
int attempts;
int work_to_do = FALSE;
HostInfo *hp;
pid_t pid;
/* First check if there is in fact any work to do. */
for (i = status_info->noOfHosts, hp = status_info->hosts; i ; i--, hp++)
{
if (hp->notifyReqd)
{
work_to_do = TRUE;
break;
}
}
if (!work_to_do) return; /* No work found */
pid = fork();
if (pid == -1)
{
syslog(LOG_ERR, "Unable to fork notify process - %s", strerror(errno));
return;
}
if (pid) return;
/* Here in the child process. We continue until all the hosts marked */
/* as requiring notification have been duly notified. */
/* If one of the initial attempts fails, we sleep for a while and */
/* have another go. This is necessary because when we have crashed, */
/* (eg. a power outage) it is quite possible that we won't be able to */
/* contact all monitored hosts immediately on restart, either because */
/* they crashed too and take longer to come up (in which case the */
/* notification isn't really required), or more importantly if some */
/* router etc. needed to reach the monitored host has not come back */
/* up yet. In this case, we will be a bit late in re-establishing */
/* locks (after the grace period) but that is the best we can do. */
/* We try 10 times at 5 sec intervals, 10 more times at 1 minute */
/* intervals, then 24 more times at hourly intervals, finally */
/* giving up altogether if the host hasn't come back to life after */
/* 24 hours. */
for (attempts = 0; attempts < 44; attempts++)
{
work_to_do = FALSE; /* Unless anything fails */
for (i = status_info->noOfHosts, hp = status_info->hosts; i ; i--, hp++)
{
if (hp->notifyReqd)
{
if (notify_one_host(hp->hostname))
{
hp->notifyReqd = FALSE;
sync_file();
}
else work_to_do = TRUE;
}
}
if (!work_to_do) break;
if (attempts < 10) sleep(5);
else if (attempts < 20) sleep(60);
else sleep(60*60);
}
exit(0);
}