1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 1998 John D. Polstra 5 * 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 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #include <sys/param.h> 32 #include <sys/mman.h> 33 #include <sys/stat.h> 34 35 #include <ctype.h> 36 #include <dirent.h> 37 #include <elf-hints.h> 38 #include <err.h> 39 #include <errno.h> 40 #include <fcntl.h> 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <unistd.h> 45 46 #include "ldconfig.h" 47 48 #define MAXDIRS 1024 /* Maximum directories in path */ 49 #define MAXFILESIZE (16*1024) /* Maximum hints file size */ 50 51 static void add_dir(const char *, const char *, bool); 52 static void read_dirs_from_file(const char *, const char *); 53 static void read_elf_hints(const char *, bool); 54 static void write_elf_hints(const char *); 55 56 static const char *dirs[MAXDIRS]; 57 static int ndirs; 58 bool insecure; 59 60 static void 61 add_dir(const char *hintsfile, const char *name, bool trusted) 62 { 63 struct stat stbuf; 64 int i; 65 66 /* Do some security checks */ 67 if (!trusted && !insecure) { 68 if (stat(name, &stbuf) == -1) { 69 warn("%s", name); 70 return; 71 } 72 if (stbuf.st_uid != 0) { 73 warnx("%s: ignoring directory not owned by root", name); 74 return; 75 } 76 if ((stbuf.st_mode & S_IWOTH) != 0) { 77 warnx("%s: ignoring world-writable directory", name); 78 return; 79 } 80 if ((stbuf.st_mode & S_IWGRP) != 0) { 81 warnx("%s: ignoring group-writable directory", name); 82 return; 83 } 84 } 85 86 for (i = 0; i < ndirs; i++) 87 if (strcmp(dirs[i], name) == 0) 88 return; 89 if (ndirs >= MAXDIRS) 90 errx(1, "\"%s\": Too many directories in path", hintsfile); 91 dirs[ndirs++] = name; 92 } 93 94 void 95 list_elf_hints(const char *hintsfile) 96 { 97 int i; 98 int nlibs; 99 100 read_elf_hints(hintsfile, 1); 101 printf("%s:\n", hintsfile); 102 printf("\tsearch directories:"); 103 for (i = 0; i < ndirs; i++) 104 printf("%c%s", i == 0 ? ' ' : ':', dirs[i]); 105 printf("\n"); 106 107 nlibs = 0; 108 for (i = 0; i < ndirs; i++) { 109 DIR *dirp; 110 struct dirent *dp; 111 112 if ((dirp = opendir(dirs[i])) == NULL) 113 continue; 114 while ((dp = readdir(dirp)) != NULL) { 115 int len; 116 int namelen; 117 const char *name; 118 const char *vers; 119 120 /* Name can't be shorter than "libx.so.0" */ 121 if ((len = strlen(dp->d_name)) < 9 || 122 strncmp(dp->d_name, "lib", 3) != 0) 123 continue; 124 name = dp->d_name + 3; 125 vers = dp->d_name + len; 126 while (vers > dp->d_name && isdigit(*(vers-1))) 127 vers--; 128 if (vers == dp->d_name + len) 129 continue; 130 if (vers < dp->d_name + 4 || 131 strncmp(vers - 4, ".so.", 4) != 0) 132 continue; 133 134 /* We have a valid shared library name. */ 135 namelen = (vers - 4) - name; 136 printf("\t%d:-l%.*s.%s => %s/%s\n", nlibs, 137 namelen, name, vers, dirs[i], dp->d_name); 138 nlibs++; 139 } 140 closedir(dirp); 141 } 142 } 143 144 static void 145 read_dirs_from_file(const char *hintsfile, const char *listfile) 146 { 147 FILE *fp; 148 char buf[MAXPATHLEN]; 149 int linenum; 150 151 if ((fp = fopen(listfile, "r")) == NULL) 152 err(1, "%s", listfile); 153 154 linenum = 0; 155 while (fgets(buf, sizeof buf, fp) != NULL) { 156 char *cp, *sp; 157 158 linenum++; 159 cp = buf; 160 /* Skip leading white space. */ 161 while (isspace(*cp)) 162 cp++; 163 if (*cp == '#' || *cp == '\0') 164 continue; 165 sp = cp; 166 /* Advance over the directory name. */ 167 while (!isspace(*cp) && *cp != '\0') 168 cp++; 169 /* Terminate the string and skip trailing white space. */ 170 if (*cp != '\0') { 171 *cp++ = '\0'; 172 while (isspace(*cp)) 173 cp++; 174 } 175 /* Now we had better be at the end of the line. */ 176 if (*cp != '\0') 177 warnx("%s:%d: trailing characters ignored", 178 listfile, linenum); 179 180 if ((sp = strdup(sp)) == NULL) 181 errx(1, "Out of memory"); 182 add_dir(hintsfile, sp, 0); 183 } 184 185 fclose(fp); 186 } 187 188 static void 189 read_elf_hints(const char *hintsfile, bool must_exist) 190 { 191 int fd; 192 struct stat s; 193 void *mapbase; 194 struct elfhints_hdr *hdr; 195 char *strtab; 196 char *dirlist; 197 char *p; 198 199 if ((fd = open(hintsfile, O_RDONLY)) == -1) { 200 if (errno == ENOENT && !must_exist) 201 return; 202 err(1, "Cannot open \"%s\"", hintsfile); 203 } 204 if (fstat(fd, &s) == -1) 205 err(1, "Cannot stat \"%s\"", hintsfile); 206 if (s.st_size > MAXFILESIZE) 207 errx(1, "\"%s\" is unreasonably large", hintsfile); 208 /* 209 * We use a read-write, private mapping so that we can null-terminate 210 * some strings in it without affecting the underlying file. 211 */ 212 mapbase = mmap(NULL, s.st_size, PROT_READ|PROT_WRITE, 213 MAP_PRIVATE, fd, 0); 214 if (mapbase == MAP_FAILED) 215 err(1, "Cannot mmap \"%s\"", hintsfile); 216 close(fd); 217 218 hdr = (struct elfhints_hdr *)mapbase; 219 if (hdr->magic != ELFHINTS_MAGIC) 220 errx(1, "\"%s\": invalid file format", hintsfile); 221 if (hdr->version != 1) 222 errx(1, "\"%s\": unrecognized file version (%d)", hintsfile, 223 hdr->version); 224 225 strtab = (char *)mapbase + hdr->strtab; 226 dirlist = strtab + hdr->dirlist; 227 228 if (*dirlist != '\0') 229 while ((p = strsep(&dirlist, ":")) != NULL) 230 add_dir(hintsfile, p, 1); 231 } 232 233 void 234 update_elf_hints(const char *hintsfile, int argc, char **argv, bool merge) 235 { 236 struct stat s; 237 int i; 238 239 if (merge) 240 read_elf_hints(hintsfile, false); 241 for (i = 0; i < argc; i++) { 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