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nlist_aout.c revision 1.2 
      1 /*	$NetBSD: nlist_aout.c,v 1.2 1996/09/30 23:49:28 cgd Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1996 Christopher G. Demetriou.  All rights reserved.
      5  * Copyright (c) 1989, 1993
      6  *	The Regents of the University of California.  All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  */
     36 
     37 #if defined(LIBC_SCCS) && !defined(lint)
     38 #if 0
     39 static char sccsid[] = "@(#)nlist.c	8.1 (Berkeley) 6/4/93";
     40 #else
     41 static char rcsid[] = "$NetBSD: nlist_aout.c,v 1.2 1996/09/30 23:49:28 cgd Exp $";
     42 #endif
     43 #endif /* LIBC_SCCS and not lint */
     44 
     45 #include <sys/param.h>
     46 #include <sys/mman.h>
     47 #include <sys/stat.h>
     48 #include <sys/file.h>
     49 
     50 #include <errno.h>
     51 #include <stdio.h>
     52 #include <string.h>
     53 #include <unistd.h>
     54 #include <a.out.h>			/* for 'struct nlist' declaration */
     55 
     56 #include "nlist_private.h"
     57 
     58 #ifdef NLIST_AOUT
     59 int
     60 __fdnlist_aout(fd, list)
     61 	register int fd;
     62 	register struct nlist *list;
     63 {
     64 	register struct nlist *p, *s;
     65 	register caddr_t strtab;
     66 	register off_t stroff, symoff;
     67 	register u_long symsize;
     68 	register int nent, cc;
     69 	size_t strsize;
     70 	struct nlist nbuf[1024];
     71 	struct exec exec;
     72 	struct stat st;
     73 
     74 	if (lseek(fd, (off_t)0, SEEK_SET) == -1 ||
     75 	    read(fd, &exec, sizeof(exec)) != sizeof(exec) ||
     76 	    N_BADMAG(exec) || fstat(fd, &st) < 0)
     77 		return (-1);
     78 
     79 	symoff = N_SYMOFF(exec);
     80 	symsize = exec.a_syms;
     81 	stroff = symoff + symsize;
     82 
     83 	/* Check for files too large to mmap. */
     84 	if (st.st_size - stroff > SIZE_T_MAX) {
     85 		errno = EFBIG;
     86 		return (-1);
     87 	}
     88 	/*
     89 	 * Map string table into our address space.  This gives us
     90 	 * an easy way to randomly access all the strings, without
     91 	 * making the memory allocation permanent as with malloc/free
     92 	 * (i.e., munmap will return it to the system).
     93 	 */
     94 	strsize = st.st_size - stroff;
     95 	strtab = mmap(NULL, (size_t)strsize, PROT_READ, 0, fd, stroff);
     96 	if (strtab == (char *)-1)
     97 		return (-1);
     98 	/*
     99 	 * clean out any left-over information for all valid entries.
    100 	 * Type and value defined to be 0 if not found; historical
    101 	 * versions cleared other and desc as well.  Also figure out
    102 	 * the largest string length so don't read any more of the
    103 	 * string table than we have to.
    104 	 *
    105 	 * XXX clearing anything other than n_type and n_value violates
    106 	 * the semantics given in the man page.
    107 	 */
    108 	nent = 0;
    109 	for (p = list; !ISLAST(p); ++p) {
    110 		p->n_type = 0;
    111 		p->n_other = 0;
    112 		p->n_desc = 0;
    113 		p->n_value = 0;
    114 		++nent;
    115 	}
    116 	if (lseek(fd, symoff, SEEK_SET) == -1)
    117 		return (-1);
    118 
    119 	while (symsize > 0) {
    120 		cc = MIN(symsize, sizeof(nbuf));
    121 		if (read(fd, nbuf, cc) != cc)
    122 			break;
    123 		symsize -= cc;
    124 		for (s = nbuf; cc > 0; ++s, cc -= sizeof(*s)) {
    125 			register int soff = s->n_un.n_strx;
    126 
    127 			if (soff == 0 || (s->n_type & N_STAB) != 0)
    128 				continue;
    129 			for (p = list; !ISLAST(p); p++)
    130 				if (!strcmp(&strtab[soff], p->n_un.n_name)) {
    131 					p->n_value = s->n_value;
    132 					p->n_type = s->n_type;
    133 					p->n_desc = s->n_desc;
    134 					p->n_other = s->n_other;
    135 					if (--nent <= 0)
    136 						break;
    137 				}
    138 		}
    139 	}
    140 	munmap(strtab, strsize);
    141 	return (nent);
    142 }
    143 #endif /* NLIST_AOUT */
    144