usr.bin/strip/strip.c

   1 /*
   2  * Copyright (c) 1988, 1993
   3  *      The Regents of the University of California.  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  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#) Copyright (c) 1988, 1993 The Regents of the University of California.  All rights reserved.
  34  * @(#)strip.c  8.1 (Berkeley) 6/6/93
  35  * $FreeBSD: src/usr.bin/strip/strip.c,v 1.12 1999/08/28 01:05:53 peter Exp $
  36  * $DragonFly: src/usr.bin/strip/Attic/strip.c,v 1.5 2005/01/01 00:22:33 cpressey Exp $
  37  */
  38
  39 #include <sys/types.h>
  40 #include <sys/stat.h>
  41 #include <sys/mman.h>
  42
  43 #include <netinet/in.h>
  44 #include <arpa/inet.h>
  45
  46 #include <a.out.h>
  47 #include <err.h>
  48 #include <errno.h>
  49 #include <fcntl.h>
  50 #include <limits.h>
  51 #include <stdio.h>
  52 #include <stdlib.h>
  53 #include <string.h>
  54 #include <unistd.h>
  55
  56 typedef struct exec EXEC;
  57 typedef struct nlist NLIST;
  58
  59 #define strx    n_un.n_strx
  60
  61 void s_stab(const char *, int, EXEC *);
  62 void s_sym(const char *, int, EXEC *);
  63 static void usage(void);
  64
  65 int xflag = 0;
  66 int err_val = 0;
  67
  68 int
  69 main(int argc, char **argv)
  70 {
  71         register int fd, nb;
  72         EXEC head;
  73         void (*sfcn)(const char *, int, EXEC *);
  74         int ch;
  75         char *fn;
  76
  77         sfcn = s_sym;
  78         while ((ch = getopt(argc, argv, "dx")) != -1)
  79                 switch(ch) {
  80                 case 'x':
  81                         xflag = 1;
  82                         /*FALLTHROUGH*/
  83                 case 'd':
  84                         sfcn = s_stab;
  85                         break;
  86                 case '?':
  87                 default:
  88                         usage();
  89                 }
  90         argc -= optind;
  91         argv += optind;
  92
  93         while ((fn = *argv++) != NULL) {
  94                 if ((fd = open(fn, O_RDWR)) < 0 ||
  95                     (nb = read(fd, &head, sizeof(EXEC))) == -1) {
  96                         warn("%s", fn);
  97                         err_val = 1;
  98                         if (fd >= 0 && close(fd)) {
  99                                 warn("%s", fn);
 100                                 err_val = 1;
 101                         }
 102                         continue;
 103                 }
 104                 if (nb != sizeof(EXEC) || N_BADMAG(head)) {
 105                         warnx("%s: %s", fn, strerror(EFTYPE));
 106                         err_val = 1;
 107                         if (close(fd)) {
 108                                 warn("%s", fn);
 109                                 err_val = 1;
 110                         }
 111                         continue;
 112                 }
 113                 sfcn(fn, fd, &head);
 114                 if (close(fd)) {
 115                         warn("%s", fn);
 116                         err_val = 1;
 117                 }
 118         }
 119         exit(err_val);
 120 }
 121
 122 void
 123 s_sym(const char *fn, int fd, register EXEC *ep)
 124 {
 125         register off_t fsize;
 126
 127         /* If no symbols or data/text relocation info, quit. */
 128         if (!ep->a_syms && !ep->a_trsize && !ep->a_drsize)
 129                 return;
 130
 131         /*
 132          * New file size is the header plus text and data segments.
 133          */
 134         fsize = N_DATOFF(*ep) + ep->a_data;
 135
 136         /* Set symbol size and relocation info values to 0. */
 137         ep->a_syms = ep->a_trsize = ep->a_drsize = 0;
 138
 139         /* Rewrite the header and truncate the file. */
 140         if (lseek(fd, (off_t)0, SEEK_SET) == -1 ||
 141             write(fd, ep, sizeof(EXEC)) != sizeof(EXEC) ||
 142             ftruncate(fd, fsize)) {
 143                 warn("%s", fn);
 144                 err_val = 1;
 145         }
 146 }
 147
 148 void
 149 s_stab(const char *fn, int fd, EXEC *ep)
 150 {
 151         register int cnt, len;
 152         register char *nstr, *nstrbase, *p, *strbase;
 153         register NLIST *sym, *nsym;
 154         struct stat sb;
 155         NLIST *symbase;
 156
 157         /* Quit if no symbols. */
 158         if (ep->a_syms == 0)
 159                 return;
 160
 161         /* Stat the file. */
 162         if (fstat(fd, &sb) < 0) {
 163                 warn("%s", fn);
 164                 err_val = 1;
 165                 return;
 166         }
 167
 168         /* Check size. */
 169         if (sb.st_size > SIZE_T_MAX) {
 170                 warnx("%s: %s", fn, strerror(EFBIG));
 171                 err_val = 1;
 172                 return;
 173         }
 174
 175         /* Map the file. */
 176         if ((ep = (EXEC *)mmap(NULL, (size_t)sb.st_size,
 177             PROT_READ | PROT_WRITE, MAP_SHARED, fd, (off_t)0)) == (EXEC *)MAP_FAILED) {
 178                 warn("%s", fn);
 179                 err_val = 1;
 180                 return;
 181         }
 182
 183         /*
 184          * Initialize old and new symbol pointers.  They both point to the
 185          * beginning of the symbol table in memory, since we're deleting
 186          * entries.
 187          */
 188         sym = nsym = symbase = (NLIST *)((char *)ep + N_SYMOFF(*ep));
 189
 190         /*
 191          * Allocate space for the new string table, initialize old and
 192          * new string pointers.  Handle the extra long at the beginning
 193          * of the string table.
 194          */
 195         strbase = (char *)ep + N_STROFF(*ep);
 196         if ((nstrbase = malloc((size_t)*(u_long *)strbase)) == NULL) {
 197                 warn(NULL);
 198                 err_val = 1;
 199                 munmap((caddr_t)ep, sb.st_size);
 200                 return;
 201         }
 202         nstr = nstrbase + sizeof(u_long);
 203
 204         /*
 205          * Read through the symbol table.  For each non-debugging symbol,
 206          * copy it and save its string in the new string table.  Keep
 207          * track of the number of symbols.
 208          */
 209         for (cnt = ep->a_syms / sizeof(NLIST); cnt--; ++sym)
 210                 if (!(sym->n_type & N_STAB) && sym->strx) {
 211                         *nsym = *sym;
 212                         nsym->strx = nstr - nstrbase;
 213                         p = strbase + sym->strx;
 214                         if (xflag &&
 215                             (!(sym->n_type & N_EXT) ||
 216                              (sym->n_type & ~N_EXT) == N_FN ||
 217                              strcmp(p, "gcc_compiled.") == 0 ||
 218                              strcmp(p, "gcc2_compiled.") == 0 ||
 219                              strcmp(p, "___gnu_compiled_c") == 0))
 220                                 continue;
 221                         len = strlen(p) + 1;
 222                         bcopy(p, nstr, len);
 223                         nstr += len;
 224                         ++nsym;
 225                 }
 226
 227         /* Fill in new symbol table size. */
 228         ep->a_syms = (nsym - symbase) * sizeof(NLIST);
 229
 230         /* Fill in the new size of the string table. */
 231         *(u_long *)nstrbase = len = nstr - nstrbase;
 232
 233         /*
 234          * Copy the new string table into place.  Nsym should be pointing
 235          * at the address past the last symbol entry.
 236          */
 237         bcopy(nstrbase, (void *)nsym, len);
 238
 239         /* Truncate to the current length. */
 240         if (ftruncate(fd, (char *)nsym + len - (char *)ep)) {
 241                 warn("%s", fn);
 242                 err_val = 1;
 243         }
 244         munmap((caddr_t)ep, (size_t)sb.st_size);
 245 }
 246
 247 static void
 248 usage(void)
 249 {
 250         (void)fprintf(stderr, "usage: strip [-dx] file ...\n");
 251         exit(1);
 252 }