1 /*- 2 * Copyright (c) 1998 John D. Polstra 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 * $FreeBSD: src/sbin/ldconfig/elfhints.c,v 1.3.2.3 2001/07/11 23:59:10 obrien Exp $ 27 * $DragonFly: src/sbin/ldconfig/elfhints.c,v 1.2 2003/06/17 04:27:33 dillon Exp $ 28 */ 29 30 #include <sys/param.h> 31 #include <sys/mman.h> 32 #include <sys/stat.h> 33 34 #include <ctype.h> 35 #include <dirent.h> 36 #include <elf-hints.h> 37 #include <err.h> 38 #include <errno.h> 39 #include <fcntl.h> 40 #include <stdio.h> 41 #include <stdlib.h> 42 #include <string.h> 43 #include <unistd.h> 44 45 #include "ldconfig.h" 46 47 #define MAXDIRS 1024 /* Maximum directories in path */ 48 #define MAXFILESIZE (16*1024) /* Maximum hints file size */ 49 50 static void add_dir(const char *, const char *, int); 51 static void read_dirs_from_file(const char *, const char *); 52 static void read_elf_hints(const char *, int); 53 static void write_elf_hints(const char *); 54 55 static const char *dirs[MAXDIRS]; 56 static int ndirs; 57 int insecure; 58 59 static void 60 add_dir(const char *hintsfile, const char *name, int trusted) 61 { 62 struct stat stbuf; 63 int i; 64 65 /* Do some security checks */ 66 if (!trusted && !insecure) { 67 if (stat(name, &stbuf) == -1) { 68 warn("%s", name); 69 return; 70 } 71 if (stbuf.st_uid != 0) { 72 warnx("%s: ignoring directory not owned by root", name); 73 return; 74 } 75 if ((stbuf.st_mode & S_IWOTH) != 0) { 76 warnx("%s: ignoring world-writable directory", name); 77 return; 78 } 79 if ((stbuf.st_mode & S_IWGRP) != 0) { 80 warnx("%s: ignoring group-writable directory", name); 81 return; 82 } 83 } 84 85 for (i = 0; i < ndirs; i++) 86 if (strcmp(dirs[i], name) == 0) 87 return; 88 if (ndirs >= MAXDIRS) 89 errx(1, "\"%s\": Too many directories in path", hintsfile); 90 dirs[ndirs++] = name; 91 } 92 93 void 94 list_elf_hints(const char *hintsfile) 95 { 96 int i; 97 int nlibs; 98 99 read_elf_hints(hintsfile, 1); 100 printf("%s:\n", hintsfile); 101 printf("\tsearch directories:"); 102 for (i = 0; i < ndirs; i++) 103 printf("%c%s", i == 0 ? ' ' : ':', dirs[i]); 104 printf("\n"); 105 106 nlibs = 0; 107 for (i = 0; i < ndirs; i++) { 108 DIR *dirp; 109 struct dirent *dp; 110 111 if ((dirp = opendir(dirs[i])) == NULL) 112 continue; 113 while ((dp = readdir(dirp)) != NULL) { 114 int len; 115 int namelen; 116 const char *name; 117 const char *vers; 118 119 /* Name can't be shorter than "libx.so.0" */ 120 if ((len = strlen(dp->d_name)) < 9 || 121 strncmp(dp->d_name, "lib", 3) != 0) 122 continue; 123 name = dp->d_name + 3; 124 vers = dp->d_name + len; 125 while (vers > dp->d_name && isdigit(*(vers-1))) 126 vers--; 127 if (vers == dp->d_name + len) 128 continue; 129 if (vers < dp->d_name + 4 || 130 strncmp(vers - 4, ".so.", 4) != 0) 131 continue; 132 133 /* We have a valid shared library name. */ 134 namelen = (vers - 4) - name; 135 printf("\t%d:-l%.*s.%s => %s/%s\n", nlibs, 136 namelen, name, vers, dirs[i], dp->d_name); 137 nlibs++; 138 } 139 closedir(dirp); 140 } 141 } 142 143 static void 144 read_dirs_from_file(const char *hintsfile, const char *listfile) 145 { 146 FILE *fp; 147 char buf[MAXPATHLEN]; 148 int linenum; 149 150 if ((fp = fopen(listfile, "r")) == NULL) 151 err(1, "%s", listfile); 152 153 linenum = 0; 154 while (fgets(buf, sizeof buf, fp) != NULL) { 155 char *cp, *sp; 156 157 linenum++; 158 cp = buf; 159 /* Skip leading white space. */ 160 while (isspace(*cp)) 161 cp++; 162 if (*cp == '#' || *cp == '\0') 163 continue; 164 sp = cp; 165 /* Advance over the directory name. */ 166 while (!isspace(*cp) && *cp != '\0') 167 cp++; 168 /* Terminate the string and skip trailing white space. */ 169 if (*cp != '\0') { 170 *cp++ = '\0'; 171 while (isspace(*cp)) 172 cp++; 173 } 174 /* Now we had better be at the end of the line. */ 175 if (*cp != '\0') 176 warnx("%s:%d: trailing characters ignored", 177 listfile, linenum); 178 179 if ((sp = strdup(sp)) == NULL) 180 errx(1, "Out of memory"); 181 add_dir(hintsfile, sp, 0); 182 } 183 184 fclose(fp); 185 } 186 187 static void 188 read_elf_hints(const char *hintsfile, int must_exist) 189 { 190 int fd; 191 struct stat s; 192 void *mapbase; 193 struct elfhints_hdr *hdr; 194 char *strtab; 195 char *dirlist; 196 char *p; 197 198 if ((fd = open(hintsfile, O_RDONLY)) == -1) { 199 if (errno == ENOENT && !must_exist) 200 return; 201 err(1, "Cannot open \"%s\"", hintsfile); 202 } 203 if (fstat(fd, &s) == -1) 204 err(1, "Cannot stat \"%s\"", hintsfile); 205 if (s.st_size > MAXFILESIZE) 206 errx(1, "\"%s\" is unreasonably large", hintsfile); 207 /* 208 * We use a read-write, private mapping so that we can null-terminate 209 * some strings in it without affecting the underlying file. 210 */ 211 mapbase = mmap(NULL, s.st_size, PROT_READ|PROT_WRITE, 212 MAP_PRIVATE, fd, 0); 213 if (mapbase == MAP_FAILED) 214 err(1, "Cannot mmap \"%s\"", hintsfile); 215 close(fd); 216 217 hdr = (struct elfhints_hdr *)mapbase; 218 if (hdr->magic != ELFHINTS_MAGIC) 219 errx(1, "\"%s\": invalid file format", hintsfile); 220 if (hdr->version != 1) 221 errx(1, "\"%s\": unrecognized file version (%d)", hintsfile, 222 hdr->version); 223 224 strtab = (char *)mapbase + hdr->strtab; 225 dirlist = strtab + hdr->dirlist; 226 227 if (*dirlist != '\0') 228 while ((p = strsep(&dirlist, ":")) != NULL) 229 add_dir(hintsfile, p, 1); 230 } 231 232 void 233 update_elf_hints(const char *hintsfile, int argc, char **argv, int merge) 234 { 235 int i; 236 237 if (merge) 238 read_elf_hints(hintsfile, 0); 239 for (i = 0; i < argc; i++) { 240 struct stat s; 241 242 if (stat(argv[i], &s) == -1) 243 warn("warning: %s", argv[i]); 244 else if (S_ISREG(s.st_mode)) 245 read_dirs_from_file(hintsfile, argv[i]); 246 else 247 add_dir(hintsfile, argv[i], 0); 248 } 249 write_elf_hints(hintsfile); 250 } 251 252 static void 253 write_elf_hints(const char *hintsfile) 254 { 255 struct elfhints_hdr hdr; 256 char *tempname; 257 int fd; 258 FILE *fp; 259 int i; 260 261 if (asprintf(&tempname, "%s.XXXXXX", hintsfile) == -1) 262 errx(1, "Out of memory"); 263 if ((fd = mkstemp(tempname)) == -1) 264 err(1, "mkstemp(%s)", tempname); 265 if (fchmod(fd, 0444) == -1) 266 err(1, "fchmod(%s)", tempname); 267 if ((fp = fdopen(fd, "wb")) == NULL) 268 err(1, "fdopen(%s)", tempname); 269 270 hdr.magic = ELFHINTS_MAGIC; 271 hdr.version = 1; 272 hdr.strtab = sizeof hdr; 273 hdr.strsize = 0; 274 hdr.dirlist = 0; 275 memset(hdr.spare, 0, sizeof hdr.spare); 276 277 /* Count up the size of the string table. */ 278 if (ndirs > 0) { 279 hdr.strsize += strlen(dirs[0]); 280 for (i = 1; i < ndirs; i++) 281 hdr.strsize += 1 + strlen(dirs[i]); 282 } 283 hdr.dirlistlen = hdr.strsize; 284 hdr.strsize++; /* For the null terminator */ 285 286 /* Write the header. */ 287 if (fwrite(&hdr, 1, sizeof hdr, fp) != sizeof hdr) 288 err(1, "%s: write error", tempname); 289 /* Write the strings. */ 290 if (ndirs > 0) { 291 if (fputs(dirs[0], fp) == EOF) 292 err(1, "%s: write error", tempname); 293 for (i = 1; i < ndirs; i++) 294 if (fprintf(fp, ":%s", dirs[i]) < 0) 295 err(1, "%s: write error", tempname); 296 } 297 if (putc('\0', fp) == EOF || fclose(fp) == EOF) 298 err(1, "%s: write error", tempname); 299 300 if (rename(tempname, hintsfile) == -1) 301 err(1, "rename %s to %s", tempname, hintsfile); 302 free(tempname); 303 } 304