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-rw-r--r--usr.sbin/rpc.statd/file.c356
1 files changed, 356 insertions, 0 deletions
diff --git a/usr.sbin/rpc.statd/file.c b/usr.sbin/rpc.statd/file.c
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+++ b/usr.sbin/rpc.statd/file.c
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+/*
+ * 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.
+ *
+ */
+
+#include <stdio.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/mman.h> /* For mmap() */
+#include <rpc/rpc.h>
+#include <syslog.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;
+ int i;
+
+ for (i = 0, hp = status_info->hosts; i < status_info->noOfHosts; i++, hp++)
+ {
+ if (!strncasecmp(hostname, hp->hostname, SM_MAXSTRLEN))
+ {
+ result = hp;
+ break;
+ }
+ if (!spare_slot && !hp->monList && !hp->notifyReqd)
+ spare_slot = hp;
+ }
+
+ /* 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(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)
+ {
+ perror("rpc.statd");
+ fprintf(stderr, "Unable to open status file %s\n", filename);
+ exit(1);
+ }
+
+ /* 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 *) -1)
+ {
+ perror("rpc.statd");
+ fprintf(stderr, "Unable to mmap() status file\n");
+ }
+
+ 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)) )
+ {
+ fprintf(stderr, "rpc.statd: status file is corrupt\n");
+ 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++;
+ }
+}
+
+/* xdr_stat_chge ----------------------------------------------------------- */
+/*
+ Purpose: XDR-encode structure of type stat_chge
+ Returns: TRUE if successful
+ Notes: This function is missing from librpcsvc, because the
+ sm_inter.x distributed by Sun omits the SM_NOTIFY
+ procedure used between co-operating statd's
+*/
+
+bool_t xdr_stat_chge(XDR *xdrs, stat_chge *objp)
+{
+ if (!xdr_string(xdrs, &objp->mon_name, SM_MAXSTRLEN))
+ {
+ return (FALSE);
+ }
+ if (!xdr_int(xdrs, &objp->state))
+ {
+ return (FALSE);
+ }
+ return (TRUE);
+}
+
+
+/* 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, xdr_stat_chge, &arg, 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);
+}
+
+
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