xref: /netbsd-src/lib/libc/gen/nlist_aout.c (revision d710132b4b8ce7f7cccaaf660cb16aa16b4077a0)
1 /* $NetBSD: nlist_aout.c,v 1.14 2003/04/20 21:08:11 christos 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 #include <sys/cdefs.h>
38 #if defined(LIBC_SCCS) && !defined(lint)
39 #if 0
40 static char sccsid[] = "@(#)nlist.c	8.1 (Berkeley) 6/4/93";
41 #else
42 __RCSID("$NetBSD: nlist_aout.c,v 1.14 2003/04/20 21:08:11 christos Exp $");
43 #endif
44 #endif /* LIBC_SCCS and not lint */
45 
46 #include "namespace.h"
47 #include <sys/param.h>
48 #include <sys/mman.h>
49 #include <sys/stat.h>
50 #include <sys/file.h>
51 
52 #include <assert.h>
53 #include <errno.h>
54 #include <stdio.h>
55 #include <string.h>
56 #include <unistd.h>
57 #include <stdlib.h>
58 #include <a.out.h>			/* for 'struct nlist' declaration */
59 
60 #include "nlist_private.h"
61 
62 #ifdef NLIST_AOUT
63 int
64 __fdnlist_aout(fd, list)
65 	int fd;
66 	struct nlist *list;
67 {
68 	struct nlist *p, *s;
69 	char *strtab;
70 	off_t stroff, symoff;
71 	int nent;
72 	size_t strsize, symsize, cc;
73 	struct nlist nbuf[1024];
74 	struct exec exec;
75 	struct stat st;
76 	char *scoreboard, *scored;
77 
78 	_DIAGASSERT(fd != -1);
79 	_DIAGASSERT(list != NULL);
80 
81 	if (pread(fd, &exec, sizeof(exec), (off_t)0) != sizeof(exec) ||
82 	    N_BADMAG(exec) || fstat(fd, &st) < 0)
83 		return (-1);
84 
85 	symoff = N_SYMOFF(exec);
86 	symsize = (size_t)exec.a_syms;
87 	stroff = symoff + symsize;
88 
89 	/* Check for files too large to mmap. */
90 	if (st.st_size - stroff > SIZE_T_MAX) {
91 		errno = EFBIG;
92 		return (-1);
93 	}
94 	/*
95 	 * Map string table into our address space.  This gives us
96 	 * an easy way to randomly access all the strings, without
97 	 * making the memory allocation permanent as with malloc/free
98 	 * (i.e., munmap will return it to the system).
99 	 */
100 	strsize = (size_t)(st.st_size - stroff);
101 	strtab = mmap(NULL, strsize, PROT_READ, MAP_PRIVATE|MAP_FILE,
102 	    fd, stroff);
103 	if (strtab == (char *)-1)
104 		return (-1);
105 	/*
106 	 * clean out any left-over information for all valid entries.
107 	 * Type and value defined to be 0 if not found; historical
108 	 * versions cleared other and desc as well.  Also figure out
109 	 * the largest string length so don't read any more of the
110 	 * string table than we have to.
111 	 *
112 	 * XXX clearing anything other than n_type and n_value violates
113 	 * the semantics given in the man page.
114 	 */
115 	nent = 0;
116 	for (p = list; !ISLAST(p); ++p) {
117 		p->n_type = 0;
118 		p->n_other = 0;
119 		p->n_desc = 0;
120 		p->n_value = 0;
121 		++nent;
122 	}
123 	if (lseek(fd, symoff, SEEK_SET) == -1)
124 		return (-1);
125 	if ((scoreboard = alloca((size_t)nent)) == NULL)
126 		return (-1);
127 	(void)memset(scoreboard, 0, (size_t)nent);
128 
129 	while (symsize > 0) {
130 		cc = MIN(symsize, sizeof(nbuf));
131 		if (read(fd, nbuf, cc) != (ssize_t) cc)
132 			break;
133 		symsize -= cc;
134 		for (s = nbuf; cc > 0; ++s, cc -= sizeof(*s)) {
135 			long soff = s->n_un.n_strx;
136 
137 			if (soff == 0 || (s->n_type & N_STAB) != 0)
138 				continue;
139 			for (p = list, scored = scoreboard; !ISLAST(p);
140 			    p++, scored++)
141 				if (*scored == 0 &&
142 				    !strcmp(&strtab[(size_t)soff],
143 				    p->n_un.n_name)) {
144 					p->n_value = s->n_value;
145 					p->n_type = s->n_type;
146 					p->n_desc = s->n_desc;
147 					p->n_other = s->n_other;
148 					*scored = 1;
149 					if (--nent <= 0)
150 						break;
151 				}
152 		}
153 	}
154 	munmap(strtab, strsize);
155 	return (nent);
156 }
157 #endif /* NLIST_AOUT */
158