1331722Seadler/* 214125Speter * Copyright (c) 1995 314125Speter * A.R. Gordon (andrew.gordon@net-tel.co.uk). All rights reserved. 414125Speter * 514125Speter * Redistribution and use in source and binary forms, with or without 614125Speter * modification, are permitted provided that the following conditions 714125Speter * are met: 814125Speter * 1. Redistributions of source code must retain the above copyright 914125Speter * notice, this list of conditions and the following disclaimer. 1014125Speter * 2. Redistributions in binary form must reproduce the above copyright 1114125Speter * notice, this list of conditions and the following disclaimer in the 1214125Speter * documentation and/or other materials provided with the distribution. 1314125Speter * 3. All advertising materials mentioning features or use of this software 1414125Speter * must display the following acknowledgement: 1514125Speter * This product includes software developed for the FreeBSD project 1614125Speter * 4. Neither the name of the author nor the names of any co-contributors 1714125Speter * may be used to endorse or promote products derived from this software 1814125Speter * without specific prior written permission. 1914125Speter * 2014125Speter * THIS SOFTWARE IS PROVIDED BY ANDREW GORDON AND CONTRIBUTORS ``AS IS'' AND 2114125Speter * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2214125Speter * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 2314125Speter * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 2414125Speter * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 2514125Speter * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 2614125Speter * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 2714125Speter * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 2814125Speter * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 2914125Speter * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3014125Speter * SUCH DAMAGE. 3114125Speter * 3274499Salfred * $FreeBSD$ 3374499Salfred * 3414125Speter */ 3514125Speter 3630376Scharnier#include <err.h> 3730376Scharnier#include <errno.h> 3830376Scharnier#include <fcntl.h> 39180025Sdfr#include <netdb.h> 4014125Speter#include <stdio.h> 4130376Scharnier#include <string.h> 4214125Speter#include <unistd.h> 4314125Speter#include <sys/types.h> 4414125Speter#include <sys/mman.h> /* For mmap() */ 4514125Speter#include <rpc/rpc.h> 4614125Speter#include <syslog.h> 4799786Salfred#include <stdlib.h> 4814125Speter 4914125Speter#include "statd.h" 5014125Speter 5114125SpeterFileLayout *status_info; /* Pointer to the mmap()ed status file */ 5214125Speterstatic int status_fd; /* File descriptor for the open file */ 5314125Speterstatic off_t status_file_len; /* Current on-disc length of file */ 5414125Speter 5514125Speter/* sync_file --------------------------------------------------------------- */ 5614125Speter/* 5714125Speter Purpose: Packaged call of msync() to flush changes to mmap()ed file 5814125Speter Returns: Nothing. Errors to syslog. 5914125Speter*/ 6014125Speter 6114125Spetervoid sync_file(void) 6214125Speter{ 6314125Speter if (msync((void *)status_info, 0, 0) < 0) 6414125Speter { 6514125Speter syslog(LOG_ERR, "msync() failed: %s", strerror(errno)); 6614125Speter } 6714125Speter} 6814125Speter 6914125Speter/* find_host -------------------------------------------------------------- */ 7014125Speter/* 7114125Speter Purpose: Find the entry in the status file for a given host 7214125Speter Returns: Pointer to that entry in the mmap() region, or NULL. 7314125Speter Notes: Also creates entries if requested. 7414125Speter Failure to create also returns NULL. 7514125Speter*/ 7614125Speter 7714125SpeterHostInfo *find_host(char *hostname, int create) 7814125Speter{ 7914125Speter HostInfo *hp; 8014125Speter HostInfo *spare_slot = NULL; 8114125Speter HostInfo *result = NULL; 82180025Sdfr struct addrinfo *ai1, *ai2; 8314125Speter int i; 8414125Speter 85299988Struckman ai2 = NULL; 86180025Sdfr if (getaddrinfo(hostname, NULL, NULL, &ai1) != 0) 87180025Sdfr ai1 = NULL; 8814125Speter for (i = 0, hp = status_info->hosts; i < status_info->noOfHosts; i++, hp++) 8914125Speter { 9014125Speter if (!strncasecmp(hostname, hp->hostname, SM_MAXSTRLEN)) 9114125Speter { 9214125Speter result = hp; 9314125Speter break; 9414125Speter } 95299988Struckman if (hp->hostname[0] != '\0' && 96180025Sdfr getaddrinfo(hp->hostname, NULL, NULL, &ai2) != 0) 97180025Sdfr ai2 = NULL; 98180025Sdfr if (ai1 && ai2) 99180025Sdfr { 100180025Sdfr struct addrinfo *p1, *p2; 101180025Sdfr for (p1 = ai1; !result && p1; p1 = p1->ai_next) 102180025Sdfr { 103180025Sdfr for (p2 = ai2; !result && p2; p2 = p2->ai_next) 104180025Sdfr { 105180025Sdfr if (p1->ai_family == p2->ai_family 106180025Sdfr && p1->ai_addrlen == p2->ai_addrlen 107180025Sdfr && !memcmp(p1->ai_addr, p2->ai_addr, p1->ai_addrlen)) 108180025Sdfr { 109180025Sdfr result = hp; 110180025Sdfr break; 111180025Sdfr } 112180025Sdfr } 113180025Sdfr } 114180025Sdfr if (result) 115180025Sdfr break; 116180025Sdfr } 117299988Struckman if (ai2) { 118180025Sdfr freeaddrinfo(ai2); 119299988Struckman ai2 = NULL; 120299988Struckman } 12114125Speter if (!spare_slot && !hp->monList && !hp->notifyReqd) 12214125Speter spare_slot = hp; 12314125Speter } 124180025Sdfr if (ai1) 125180025Sdfr freeaddrinfo(ai1); 12614125Speter 12714125Speter /* Return if entry found, or if not asked to create one. */ 12814125Speter if (result || !create) return (result); 12914125Speter 13014125Speter /* Now create an entry, using the spare slot if one was found or */ 13114125Speter /* adding to the end of the list otherwise, extending file if reqd */ 13214125Speter if (!spare_slot) 13314125Speter { 13414125Speter off_t desired_size; 13514125Speter spare_slot = &status_info->hosts[status_info->noOfHosts]; 13614125Speter desired_size = ((char*)spare_slot - (char*)status_info) + sizeof(HostInfo); 13714125Speter if (desired_size > status_file_len) 13814125Speter { 13914125Speter /* Extend file by writing 1 byte of junk at the desired end pos */ 140299988Struckman if (lseek(status_fd, desired_size - 1, SEEK_SET) == -1 || 141299988Struckman write(status_fd, "\0", 1) < 0) 14214125Speter { 14314125Speter syslog(LOG_ERR, "Unable to extend status file"); 14414125Speter return (NULL); 14514125Speter } 14614125Speter status_file_len = desired_size; 14714125Speter } 14814125Speter status_info->noOfHosts++; 14914125Speter } 15014125Speter 15114125Speter /* Initialise the spare slot that has been found/created */ 15214125Speter /* Note that we do not msync(), since the caller is presumed to be */ 15314125Speter /* about to modify the entry further */ 15414125Speter memset(spare_slot, 0, sizeof(HostInfo)); 15514125Speter strncpy(spare_slot->hostname, hostname, SM_MAXSTRLEN); 15614125Speter return (spare_slot); 15714125Speter} 15814125Speter 15914125Speter/* init_file -------------------------------------------------------------- */ 16014125Speter/* 16114125Speter Purpose: Open file, create if necessary, initialise it. 16214125Speter Returns: Nothing - exits on error 16314125Speter Notes: Called before process becomes daemon, hence logs to 16414125Speter stderr rather than syslog. 16514125Speter Opens the file, then mmap()s it for ease of access. 16614125Speter Also performs initial clean-up of the file, zeroing 16714125Speter monitor list pointers, setting the notifyReqd flag in 16814125Speter all hosts that had a monitor list, and incrementing 16914125Speter the state number to the next even value. 17014125Speter*/ 17114125Speter 17299798Salfredvoid init_file(const char *filename) 17314125Speter{ 17414125Speter int new_file = FALSE; 17514125Speter char buf[HEADER_LEN]; 17614125Speter int i; 17714125Speter 17814125Speter /* try to open existing file - if not present, create one */ 17914125Speter status_fd = open(filename, O_RDWR); 18014125Speter if ((status_fd < 0) && (errno == ENOENT)) 18114125Speter { 18214125Speter status_fd = open(filename, O_RDWR | O_CREAT, 0644); 18314125Speter new_file = TRUE; 18414125Speter } 18514125Speter if (status_fd < 0) 18630376Scharnier errx(1, "unable to open status file %s", filename); 18714125Speter 18814125Speter /* File now open. mmap() it, with a generous size to allow for */ 18914125Speter /* later growth, where we will extend the file but not re-map it. */ 19014125Speter status_info = (FileLayout *) 19114125Speter mmap(NULL, 0x10000000, PROT_READ | PROT_WRITE, MAP_SHARED, status_fd, 0); 19214125Speter 19321786Salex if (status_info == (FileLayout *) MAP_FAILED) 194171816Struckman err(1, "unable to mmap() status file"); 19514125Speter 19614125Speter status_file_len = lseek(status_fd, 0L, SEEK_END); 19714125Speter 19814125Speter /* If the file was not newly created, validate the contents, and if */ 19914125Speter /* defective, re-create from scratch. */ 20014125Speter if (!new_file) 20114125Speter { 20214125Speter if ((status_file_len < HEADER_LEN) || (status_file_len 20314125Speter < (HEADER_LEN + sizeof(HostInfo) * status_info->noOfHosts)) ) 20414125Speter { 20530376Scharnier warnx("status file is corrupt"); 20614125Speter new_file = TRUE; 20714125Speter } 20814125Speter } 20914125Speter 21014125Speter /* Initialisation of a new, empty file. */ 21114125Speter if (new_file) 21214125Speter { 21314125Speter memset(buf, 0, sizeof(buf)); 21414125Speter lseek(status_fd, 0L, SEEK_SET); 21514125Speter write(status_fd, buf, HEADER_LEN); 21614125Speter status_file_len = HEADER_LEN; 21714125Speter } 21814125Speter else 21914125Speter { 22014125Speter /* Clean-up of existing file - monitored hosts will have a pointer */ 22114125Speter /* to a list of clients, which refers to memory in the previous */ 22214125Speter /* incarnation of the program and so are meaningless now. These */ 22314125Speter /* pointers are zeroed and the fact that the host was previously */ 22414125Speter /* monitored is recorded by setting the notifyReqd flag, which will */ 22514125Speter /* in due course cause a SM_NOTIFY to be sent. */ 22614125Speter /* Note that if we crash twice in quick succession, some hosts may */ 22714125Speter /* already have notifyReqd set, where we didn't manage to notify */ 22814125Speter /* them before the second crash occurred. */ 22914125Speter for (i = 0; i < status_info->noOfHosts; i++) 23014125Speter { 23114125Speter HostInfo *this_host = &status_info->hosts[i]; 23214125Speter 23314125Speter if (this_host->monList) 23414125Speter { 23514125Speter this_host->notifyReqd = TRUE; 23614125Speter this_host->monList = NULL; 23714125Speter } 23814125Speter } 23914125Speter /* Select the next higher even number for the state counter */ 24014125Speter status_info->ourState = (status_info->ourState + 2) & 0xfffffffe; 24114125Speter/*???????******/ status_info->ourState++; 24214125Speter } 24314125Speter} 24414125Speter 24514125Speter/* notify_one_host --------------------------------------------------------- */ 24614125Speter/* 24714125Speter Purpose: Perform SM_NOTIFY procedure at specified host 24814125Speter Returns: TRUE if success, FALSE if failed. 24914125Speter*/ 25014125Speter 25114125Speterstatic int notify_one_host(char *hostname) 25214125Speter{ 25314125Speter struct timeval timeout = { 20, 0 }; /* 20 secs timeout */ 25414125Speter CLIENT *cli; 25514125Speter char dummy; 25614125Speter stat_chge arg; 25714125Speter char our_hostname[SM_MAXSTRLEN+1]; 25814125Speter 25914125Speter gethostname(our_hostname, sizeof(our_hostname)); 26014125Speter our_hostname[SM_MAXSTRLEN] = '\0'; 26114125Speter arg.mon_name = our_hostname; 26214125Speter arg.state = status_info->ourState; 26314125Speter 26414125Speter if (debug) syslog (LOG_DEBUG, "Sending SM_NOTIFY to host %s from %s", hostname, our_hostname); 26514125Speter 26614125Speter cli = clnt_create(hostname, SM_PROG, SM_VERS, "udp"); 26714125Speter if (!cli) 26814125Speter { 26914125Speter syslog(LOG_ERR, "Failed to contact host %s%s", hostname, 27014125Speter clnt_spcreateerror("")); 27114125Speter return (FALSE); 27214125Speter } 27314125Speter 274121560Speter if (clnt_call(cli, SM_NOTIFY, (xdrproc_t)xdr_stat_chge, &arg, 275121560Speter (xdrproc_t)xdr_void, &dummy, timeout) 27614125Speter != RPC_SUCCESS) 27714125Speter { 27814125Speter syslog(LOG_ERR, "Failed to contact rpc.statd at host %s", hostname); 27914125Speter clnt_destroy(cli); 28014125Speter return (FALSE); 28114125Speter } 28214125Speter 28314125Speter clnt_destroy(cli); 28414125Speter return (TRUE); 28514125Speter} 28614125Speter 28714125Speter/* notify_hosts ------------------------------------------------------------ */ 28814125Speter/* 28914125Speter Purpose: Send SM_NOTIFY to all hosts marked as requiring it 29014125Speter Returns: Nothing, immediately - forks a process to do the work. 29114125Speter Notes: Does nothing if there are no monitored hosts. 29214125Speter Called after all the initialisation has been done - 29314125Speter logs to syslog. 29414125Speter*/ 29514125Speter 29614125Spetervoid notify_hosts(void) 29714125Speter{ 29814125Speter int i; 29914125Speter int attempts; 30014125Speter int work_to_do = FALSE; 30114125Speter HostInfo *hp; 30214125Speter pid_t pid; 30314125Speter 30414125Speter /* First check if there is in fact any work to do. */ 30514125Speter for (i = status_info->noOfHosts, hp = status_info->hosts; i ; i--, hp++) 30614125Speter { 30714125Speter if (hp->notifyReqd) 30814125Speter { 30914125Speter work_to_do = TRUE; 31014125Speter break; 31114125Speter } 31214125Speter } 31314125Speter 31414125Speter if (!work_to_do) return; /* No work found */ 31514125Speter 31614125Speter pid = fork(); 31714125Speter if (pid == -1) 31814125Speter { 31914125Speter syslog(LOG_ERR, "Unable to fork notify process - %s", strerror(errno)); 32014125Speter return; 32114125Speter } 32214125Speter if (pid) return; 32314125Speter 32414125Speter /* Here in the child process. We continue until all the hosts marked */ 32514125Speter /* as requiring notification have been duly notified. */ 32614125Speter /* If one of the initial attempts fails, we sleep for a while and */ 32714125Speter /* have another go. This is necessary because when we have crashed, */ 32814125Speter /* (eg. a power outage) it is quite possible that we won't be able to */ 32914125Speter /* contact all monitored hosts immediately on restart, either because */ 33014125Speter /* they crashed too and take longer to come up (in which case the */ 33114125Speter /* notification isn't really required), or more importantly if some */ 33214125Speter /* router etc. needed to reach the monitored host has not come back */ 33314125Speter /* up yet. In this case, we will be a bit late in re-establishing */ 33414125Speter /* locks (after the grace period) but that is the best we can do. */ 33514125Speter /* We try 10 times at 5 sec intervals, 10 more times at 1 minute */ 33614125Speter /* intervals, then 24 more times at hourly intervals, finally */ 33714125Speter /* giving up altogether if the host hasn't come back to life after */ 33814125Speter /* 24 hours. */ 33914125Speter 34014125Speter for (attempts = 0; attempts < 44; attempts++) 34114125Speter { 34214125Speter work_to_do = FALSE; /* Unless anything fails */ 34314125Speter for (i = status_info->noOfHosts, hp = status_info->hosts; i ; i--, hp++) 34414125Speter { 34514125Speter if (hp->notifyReqd) 34614125Speter { 34714125Speter if (notify_one_host(hp->hostname)) 34814125Speter { 34914125Speter hp->notifyReqd = FALSE; 35014125Speter sync_file(); 35114125Speter } 35214125Speter else work_to_do = TRUE; 35314125Speter } 35414125Speter } 35514125Speter if (!work_to_do) break; 35614125Speter if (attempts < 10) sleep(5); 35714125Speter else if (attempts < 20) sleep(60); 35814125Speter else sleep(60*60); 35914125Speter } 36014125Speter exit(0); 36114125Speter} 36214125Speter 36314125Speter 364