1 /* $OpenBSD: db.c,v 1.15 2016/02/06 23:50:10 krw Exp $ */ 2 3 /* 4 * Persistent database management routines for DHCPD. 5 */ 6 7 /* 8 * Copyright (c) 1995, 1996 The Internet Software Consortium. 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of The Internet Software Consortium nor the names 21 * of its contributors may be used to endorse or promote products derived 22 * from this software without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE INTERNET SOFTWARE CONSORTIUM AND 25 * CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, 26 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 27 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 28 * DISCLAIMED. IN NO EVENT SHALL THE INTERNET SOFTWARE CONSORTIUM OR 29 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF 32 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 33 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 34 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT 35 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 * 38 * This software has been written for the Internet Software Consortium 39 * by Ted Lemon <mellon@fugue.com> in cooperation with Vixie 40 * Enterprises. To learn more about the Internet Software Consortium, 41 * see ``http://www.vix.com/isc''. To learn more about Vixie 42 * Enterprises, see ``http://www.vix.com''. 43 */ 44 45 #include <sys/types.h> 46 #include <sys/socket.h> 47 48 #include <net/if.h> 49 50 #include <netinet/in.h> 51 52 #include <fcntl.h> 53 #include <stdio.h> 54 #include <unistd.h> 55 56 #include "dhcp.h" 57 #include "tree.h" 58 #include "dhcpd.h" 59 60 FILE *db_file; 61 62 static int counting = 0; 63 static int count = 0; 64 time_t write_time; 65 66 /* 67 * Write the specified lease to the current lease database file. 68 */ 69 int 70 write_lease(struct lease *lease) 71 { 72 char tbuf[26]; /* "w yyyy/mm/dd hh:mm:ss UTC" */ 73 size_t rsltsz; 74 int errors = 0; 75 int i; 76 77 if (counting) 78 ++count; 79 if (fprintf(db_file, "lease %s {\n", piaddr(lease->ip_addr)) == -1) 80 ++errors; 81 82 rsltsz = strftime(tbuf, sizeof(tbuf), DB_TIMEFMT, 83 gmtime(&lease->starts)); 84 if (rsltsz == 0 || fprintf(db_file, "\tstarts %s;\n", tbuf) == -1) 85 errors++; 86 87 rsltsz = strftime(tbuf, sizeof(tbuf), DB_TIMEFMT, 88 gmtime(&lease->ends)); 89 if (rsltsz == 0 || fprintf(db_file, "\tends %s;\n", tbuf) == -1) 90 errors++; 91 92 if (lease->hardware_addr.hlen) { 93 if (fprintf(db_file, "\thardware %s %s;", 94 hardware_types[lease->hardware_addr.htype], 95 print_hw_addr(lease->hardware_addr.htype, 96 lease->hardware_addr.hlen, 97 lease->hardware_addr.haddr)) == -1) 98 ++errors; 99 } 100 101 if (lease->uid_len) { 102 int j; 103 104 if (fprintf(db_file, "\n\tuid %2.2x", lease->uid[0]) == -1) 105 ++errors; 106 107 for (j = 1; j < lease->uid_len; j++) { 108 if (fprintf(db_file, ":%2.2x", lease->uid[j]) == -1) 109 ++errors; 110 } 111 if (fputc(';', db_file) == EOF) 112 ++errors; 113 } 114 115 if (lease->flags & BOOTP_LEASE) { 116 if (fprintf(db_file, "\n\tdynamic-bootp;") == -1) 117 ++errors; 118 } 119 120 if (lease->flags & ABANDONED_LEASE) { 121 if (fprintf(db_file, "\n\tabandoned;") == -1) 122 ++errors; 123 } 124 125 if (lease->client_hostname) { 126 for (i = 0; lease->client_hostname[i]; i++) 127 if (lease->client_hostname[i] < 33 || 128 lease->client_hostname[i] > 126) 129 goto bad_client_hostname; 130 if (fprintf(db_file, "\n\tclient-hostname \"%s\";", 131 lease->client_hostname) == -1) 132 ++errors; 133 } 134 135 bad_client_hostname: 136 if (lease->hostname) { 137 for (i = 0; lease->hostname[i]; i++) 138 if (lease->hostname[i] < 33 || 139 lease->hostname[i] > 126) 140 goto bad_hostname; 141 if (fprintf(db_file, "\n\thostname \"%s\";", 142 lease->hostname) == -1) 143 ++errors; 144 } 145 146 bad_hostname: 147 if (fputs("\n}\n", db_file) == EOF) 148 ++errors; 149 150 if (errors) 151 note("write_lease: unable to write lease %s", 152 piaddr(lease->ip_addr)); 153 154 return (!errors); 155 } 156 157 /* 158 * Commit any leases that have been written out... 159 */ 160 int 161 commit_leases(void) 162 { 163 /* 164 * Commit any outstanding writes to the lease database file. We need to 165 * do this even if we're rewriting the file below, just in case the 166 * rewrite fails. 167 */ 168 if (fflush(db_file) == EOF) { 169 note("commit_leases: unable to commit: %m"); 170 return (0); 171 } 172 173 if (fsync(fileno(db_file)) == -1) { 174 note("commit_leases: unable to commit: %m"); 175 return (0); 176 } 177 178 /* 179 * If we've written more than a thousand leases or if we haven't 180 * rewritten the lease database in over an hour, rewrite it now. 181 */ 182 if (count > 1000 || (count && cur_time - write_time > 3600)) { 183 count = 0; 184 write_time = cur_time; 185 new_lease_file(); 186 } 187 188 return (1); 189 } 190 191 void 192 db_startup(void) 193 { 194 int db_fd; 195 196 /* open lease file. once we dropped privs it has to stay open */ 197 db_fd = open(path_dhcpd_db, O_WRONLY|O_CREAT, 0640); 198 if (db_fd == -1) 199 error("Can't create new lease file: %m"); 200 if ((db_file = fdopen(db_fd, "w")) == NULL) 201 error("Can't fdopen new lease file!"); 202 203 /* Read in the existing lease file... */ 204 read_leases(); 205 time(&write_time); 206 207 new_lease_file(); 208 } 209 210 void 211 new_lease_file(void) 212 { 213 fflush(db_file); 214 rewind(db_file); 215 216 /* Write out all the leases that we know of... */ 217 counting = 0; 218 write_leases(); 219 220 fflush(db_file); 221 ftruncate(fileno(db_file), ftello(db_file)); 222 fsync(fileno(db_file)); 223 224 counting = 1; 225 } 226