1 /*- 2 * SPDX-License-Identifier: BSD-4-Clause 3 * 4 * Copyright (c) 1995 5 * A.R. Gordon (andrew.gordon@net-tel.co.uk). All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed for the FreeBSD project 18 * 4. Neither the name of the author nor the names of any co-contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY ANDREW GORDON AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * $FreeBSD$ 35 */ 36 37 38 39 #include "sm_inter.h" 40 41 /* ------------------------------------------------------------------------- */ 42 /* 43 Data structures for recording monitored hosts 44 45 The information held by the status monitor comprises a list of hosts 46 that we have been asked to monitor, and, associated with each monitored 47 host, one or more clients to be called back if the monitored host crashes. 48 49 The list of monitored hosts must be retained over a crash, so that upon 50 re-boot we can call the SM_NOTIFY procedure in all those hosts so as to 51 cause them to start recovery processing. On the other hand, the client 52 call-backs are not required to be preserved: they are assumed (in the 53 protocol design) to be local processes which will have crashed when 54 we did, and so are discarded on restart. 55 56 We handle this by keeping the list of monitored hosts in a file 57 (/var/statd.state) which is mmap()ed and whose format is described 58 by the typedef FileLayout. The lists of client callbacks are chained 59 off this structure, but are held in normal memory and so will be 60 lost after a re-boot. Hence the actual values of MonList * pointers 61 in the copy on disc have no significance, but their NULL/non-NULL 62 status indicates whether this host is actually being monitored or if it 63 is an empty slot in the file. 64 */ 65 66 typedef struct MonList_s 67 { 68 struct MonList_s *next; /* Next in list or NULL */ 69 char notifyHost[SM_MAXSTRLEN + 1]; /* Host to notify */ 70 int notifyProg; /* RPC program number to call */ 71 int notifyVers; /* version number */ 72 int notifyProc; /* procedure number */ 73 unsigned char notifyData[16]; /* Opaque data from caller */ 74 } MonList; 75 76 typedef struct 77 { 78 char hostname[SM_MAXSTRLEN + 1]; /* Name of monitored host */ 79 int notifyReqd; /* TRUE if we've crashed and not yet */ 80 /* informed the monitored host */ 81 MonList *monList; /* List of clients to inform if we */ 82 /* hear that the monitored host has */ 83 /* crashed, NULL if no longer monitored */ 84 } HostInfo; 85 86 87 /* Overall file layout. */ 88 89 typedef struct 90 { 91 int ourState; /* State number as defined in statd protocol */ 92 int noOfHosts; /* Number of elements in hosts[] */ 93 char reserved[248]; /* Reserved for future use */ 94 HostInfo hosts[1]; /* vector of monitored hosts */ 95 } FileLayout; 96 97 #define HEADER_LEN (sizeof(FileLayout) - sizeof(HostInfo)) 98 99 /* ------------------------------------------------------------------------- */ 100 101 /* Global variables */ 102 103 extern FileLayout *status_info; /* The mmap()ed status file */ 104 105 extern int debug; /* =1 to enable diagnostics to syslog */ 106 107 /* Function prototypes */ 108 109 extern HostInfo *find_host(char * /*hostname*/, int /*create*/); 110 extern void init_file(const char * /*filename*/); 111 extern void notify_hosts(void); 112 extern void sync_file(void); 113 extern int sm_check_hostname(struct svc_req *req, char *arg); 114