1 /* $NetBSD: binpatch.c,v 1.5 2009/03/14 21:04:07 dsl Exp $ */ 2 3 /* 4 * Copyright (c) 1994 Christian E. Hopps 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 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Christian E. Hopps. 18 * 4. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 #include <sys/types.h> 34 #include <a.out.h> 35 #include <stdio.h> 36 #include <stdlib.h> 37 38 extern char *optarg; 39 extern int optind; 40 41 void error (char *) __attribute__((__noreturn__)); 42 43 int test = 1; 44 int testbss; 45 char foo = 23; 46 47 48 int 49 main(int argc, char *argv[]) 50 { 51 struct exec e; 52 int c; 53 u_long addr = 0, offset = 0; 54 u_long replace = 0, do_replace = 0; 55 char *symbol = 0; 56 char size = 4; /* default to long */ 57 char *fname; 58 int fd; 59 int type, off; 60 u_long lval; 61 u_short sval; 62 u_char cval; 63 64 65 while ((c = getopt (argc, argv, "a:bwlr:s:o:")) != -1) 66 switch (c) 67 { 68 case 'a': 69 if (addr || symbol) 70 error ("only one address/symbol allowed"); 71 if (! strncmp (optarg, "0x", 2)) 72 sscanf (optarg, "%x", &addr); 73 else 74 addr = atoi (optarg); 75 if (! addr) 76 error ("invalid address"); 77 break; 78 79 case 'b': 80 size = 1; 81 break; 82 83 case 'w': 84 size = 2; 85 break; 86 87 case 'l': 88 size = 4; 89 break; 90 91 case 'r': 92 do_replace = 1; 93 if (! strncmp (optarg, "0x", 2)) 94 sscanf (optarg, "%x", &replace); 95 else 96 replace = atoi (optarg); 97 break; 98 99 case 's': 100 if (addr || symbol) 101 error ("only one address/symbol allowed"); 102 symbol = optarg; 103 break; 104 105 case 'o': 106 if (offset) 107 error ("only one offset allowed"); 108 if (! strncmp (optarg, "0x", 2)) 109 sscanf (optarg, "%x", &offset); 110 else 111 offset = atoi (optarg); 112 break; 113 } 114 115 argv += optind; 116 argc -= optind; 117 118 119 if (argc < 1) 120 error ("No file to patch."); 121 122 fname = argv[0]; 123 if ((fd = open (fname, 0)) < 0) 124 error ("Can't open file"); 125 126 if (read (fd, &e, sizeof (e)) != sizeof (e) 127 || N_BADMAG (e)) 128 error ("Not a valid executable."); 129 130 /* fake mid, so the N_ macros work on the amiga.. */ 131 e.a_midmag |= 127 << 16; 132 133 if (symbol) 134 { 135 struct nlist nl[2]; 136 nl[0].n_un.n_name = symbol; 137 nl[1].n_un.n_name = 0; 138 if (nlist (fname, nl) != 0) 139 error ("Symbol not found."); 140 addr = nl[0].n_value; 141 type = nl[0].n_type & N_TYPE; 142 } 143 else 144 { 145 type = N_UNDF; 146 if (addr >= N_TXTADDR(e) && addr < N_DATADDR(e)) 147 type = N_TEXT; 148 else if (addr >= N_DATADDR(e) && addr < N_DATADDR(e) + e.a_data) 149 type = N_DATA; 150 } 151 addr += offset; 152 153 /* if replace-mode, have to reopen the file for writing. 154 Can't do that from the beginning, or nlist() will not 155 work (at least not under AmigaDOS) */ 156 if (do_replace) 157 { 158 close (fd); 159 if ((fd = open (fname, 2)) == -1) 160 error ("Can't reopen file for writing."); 161 } 162 163 if (type != N_TEXT && type != N_DATA) 164 error ("address/symbol is not in text or data section."); 165 166 if (type == N_TEXT) 167 off = addr - N_TXTADDR(e) + N_TXTOFF(e); 168 else 169 off = addr - N_DATADDR(e) + N_DATOFF(e); 170 171 if (lseek (fd, off, 0) == -1) 172 error ("lseek"); 173 174 /* not beautiful, but works on big and little endian machines */ 175 switch (size) 176 { 177 case 1: 178 if (read (fd, &cval, 1) != 1) 179 error ("cread"); 180 lval = cval; 181 break; 182 183 case 2: 184 if (read (fd, &sval, 2) != 2) 185 error ("sread"); 186 lval = sval; 187 break; 188 189 case 4: 190 if (read (fd, &lval, 4) != 4) 191 error ("lread"); 192 break; 193 } 194 195 196 if (symbol) 197 printf ("%s(0x%x): %d (0x%x)\n", symbol, addr, lval, lval); 198 else 199 printf ("0x%x: %d (0x%x)\n", addr, lval, lval); 200 201 if (do_replace) 202 { 203 if (lseek (fd, off, 0) == -1) 204 error ("write-lseek"); 205 switch (size) 206 { 207 case 1: 208 cval = replace; 209 if (cval != replace) 210 error ("byte-value overflow."); 211 if (write (fd, &cval, 1) != 1) 212 error ("cwrite"); 213 break; 214 215 case 2: 216 sval = replace; 217 if (sval != replace) 218 error ("word-value overflow."); 219 if (write (fd, &sval, 2) != 2) 220 error ("swrite"); 221 break; 222 223 case 4: 224 if (write (fd, &replace, 4) != 4) 225 error ("lwrite"); 226 break; 227 } 228 } 229 230 close (fd); 231 } 232 233 234 235 void error (str) 236 char *str; 237 { 238 fprintf (stderr, "%s\n", str); 239 exit (1); 240 } 241