1 /* $OpenBSD: kvm_mkdb.c,v 1.33 2021/10/24 21:24:18 deraadt Exp $ */ 2 3 /*- 4 * Copyright (c) 1990, 1993 5 * The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29 * SUCH DAMAGE. 30 */ 31 32 #include <sys/stat.h> 33 #include <sys/types.h> 34 #include <sys/time.h> 35 #include <sys/resource.h> 36 37 #include <db.h> 38 #include <err.h> 39 #include <errno.h> 40 #include <fcntl.h> 41 #include <libgen.h> 42 #include <paths.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <unistd.h> 47 #include <grp.h> 48 49 #include "extern.h" 50 51 __dead void usage(void); 52 int kvm_mkdb(int, const char *, char *, char *, gid_t, int); 53 54 HASHINFO openinfo = { 55 4096, /* bsize */ 56 128, /* ffactor */ 57 1024, /* nelem */ 58 2048 * 1024, /* cachesize */ 59 NULL, /* hash() */ 60 0 /* lorder */ 61 }; 62 63 int 64 main(int argc, char *argv[]) 65 { 66 struct rlimit rl; 67 struct group *gr; 68 gid_t kvm_gid = -1; 69 int fd, rval, ch, verbose = 0; 70 char *nlistpath, *nlistname; 71 char dbdir[PATH_MAX]; 72 73 if (pledge("stdio rpath wpath cpath fattr getpw flock id unveil", NULL) == -1) 74 err(1, "pledge"); 75 76 /* Try to use the kmem group to be able to fchown() in kvm_mkdb(). */ 77 if ((gr = getgrnam("kmem")) == NULL) { 78 warn("can't find kmem group"); 79 } else { 80 kvm_gid = gr->gr_gid; 81 if (setresgid(kvm_gid, kvm_gid, kvm_gid) == -1) 82 err(1, "setresgid"); 83 } 84 85 /* Increase our data size to the max if we can. */ 86 if (getrlimit(RLIMIT_DATA, &rl) == 0) { 87 rl.rlim_cur = rl.rlim_max; 88 if (setrlimit(RLIMIT_DATA, &rl) == -1) 89 warn("can't set rlimit data size"); 90 } 91 92 if (pledge("stdio rpath wpath cpath fattr flock unveil", NULL) == -1) 93 err(1, "pledge"); 94 95 strlcpy(dbdir, _PATH_VARDB, sizeof(dbdir)); 96 while ((ch = getopt(argc, argv, "vo:")) != -1) 97 switch (ch) { 98 case 'v': 99 verbose = 1; 100 break; 101 case 'o': 102 rval = strlcpy(dbdir, optarg, sizeof(dbdir)); 103 if (rval == 0 || rval + 1 >= sizeof(dbdir)) 104 errx(1, "Invalid directory"); 105 /* Make sure there is a '/' at the end of the path */ 106 if (dbdir[strlen(dbdir) - 1] != '/') 107 strlcat(dbdir, "/", sizeof(dbdir)); 108 break; 109 default: 110 usage(); 111 } 112 argc -= optind; 113 argv += optind; 114 115 if (argc > 1) 116 usage(); 117 118 if (argc > 0) { 119 if (unveil(argv[0], "r") == -1) 120 err(1, "unveil %s", argv[0]); 121 } else { 122 if (unveil(_PATH_UNIX, "r") == -1) 123 err(1, "unveil %s", _PATH_UNIX); 124 if (unveil(_PATH_KSYMS, "r") == -1) 125 err(1, "unveil %s", _PATH_KSYMS); 126 } 127 if (unveil(dbdir, "rwc") == -1) 128 err(1, "unveil %s", dbdir); 129 if (pledge("stdio rpath wpath cpath fattr flock", NULL) == -1) 130 err(1, "pledge"); 131 132 /* If no kernel specified use _PATH_KSYMS and fall back to _PATH_UNIX */ 133 if (argc > 0) { 134 nlistpath = argv[0]; 135 nlistname = basename(nlistpath); 136 if ((fd = open(nlistpath, O_RDONLY)) == -1) 137 err(1, "can't open %s", nlistpath); 138 rval = kvm_mkdb(fd, dbdir, nlistpath, nlistname, kvm_gid, 139 verbose); 140 } else { 141 nlistname = basename(_PATH_UNIX); 142 if ((fd = open((nlistpath = _PATH_KSYMS), O_RDONLY)) == -1 || 143 (rval = kvm_mkdb(fd, dbdir, nlistpath, nlistname, kvm_gid, 144 verbose)) != 0) { 145 if (fd == -1) 146 warnx("can't open %s", _PATH_KSYMS); 147 else 148 warnx("will try again using %s instead", _PATH_UNIX); 149 if ((fd = open((nlistpath = _PATH_UNIX), O_RDONLY)) == -1) 150 err(1, "can't open %s", nlistpath); 151 rval = kvm_mkdb(fd, dbdir, nlistpath, nlistname, 152 kvm_gid, verbose); 153 } 154 } 155 exit(rval); 156 } 157 158 int 159 kvm_mkdb(int fd, const char *dbdir, char *nlistpath, char *nlistname, gid_t gid, 160 int verbose) 161 { 162 DB *db; 163 char dbtemp[PATH_MAX], dbname[PATH_MAX]; 164 int r; 165 166 r = snprintf(dbtemp, sizeof(dbtemp), "%skvm_%s.tmp", 167 dbdir, nlistname); 168 if (r < 0 || r >= sizeof(dbtemp)) { 169 warnx("Directory name too long"); 170 return (1); 171 } 172 r = snprintf(dbname, sizeof(dbname), "%skvm_%s.db", 173 dbdir, nlistname); 174 if (r < 0 || r >= sizeof(dbtemp)) { 175 warnx("Directory name too long"); 176 return (1); 177 } 178 179 /* If the existing db file matches the currently running kernel, exit */ 180 if (testdb(dbname)) { 181 if (verbose) 182 warnx("%s already up to date", dbname); 183 return(0); 184 } else if (verbose) 185 warnx("rebuilding %s", dbname); 186 187 (void)umask(0); 188 db = dbopen(dbtemp, O_CREAT | O_EXLOCK | O_TRUNC | O_RDWR, 189 S_IRUSR | S_IWUSR | S_IRGRP, DB_HASH, &openinfo); 190 if (db == NULL) { 191 warn("can't dbopen %s", dbtemp); 192 return(1); 193 } 194 195 if (gid != -1 && fchown(db->fd(db), -1, gid) == -1) { 196 warn("can't chown %s", dbtemp); 197 (void)unlink(dbtemp); 198 return(1); 199 } 200 201 if (create_knlist(nlistpath, fd, db) != 0) { 202 warn("cannot determine executable type of %s", nlistpath); 203 (void)unlink(dbtemp); 204 return(1); 205 } 206 if (db->close(db)) { 207 warn("can't dbclose %s", dbtemp); 208 (void)unlink(dbtemp); 209 return(1); 210 } 211 212 if (rename(dbtemp, dbname)) { 213 warn("rename %s to %s", dbtemp, dbname); 214 (void)unlink(dbtemp); 215 return(1); 216 } 217 218 return(0); 219 } 220 221 __dead void 222 usage(void) 223 { 224 (void)fprintf(stderr, "usage: kvm_mkdb [-v] [-o directory] [file]\n"); 225 exit(1); 226 } 227