xref: /netbsd-src/lib/libc/gen/nlist_aout.c (revision 76dfffe33547c37f8bdd446e3e4ab0f3c16cea4b)
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