xref: /netbsd/lib/libc/gen/nlist_aout.c (revision c4a72b64)
1 /* $NetBSD: nlist_aout.c,v 1.13 2002/11/11 19:26:49 thorpej 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 1.13 2002/11/11 19:26:49 thorpej 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 <a.out.h>			/* for 'struct nlist' declaration */
58 
59 #include "nlist_private.h"
60 
61 #ifdef NLIST_AOUT
62 int
63 __fdnlist_aout(fd, list)
64 	int fd;
65 	struct nlist *list;
66 {
67 	struct nlist *p, *s;
68 	char *strtab;
69 	off_t stroff, symoff;
70 	int nent;
71 	size_t strsize, symsize, cc;
72 	struct nlist nbuf[1024];
73 	struct exec exec;
74 	struct stat st;
75 
76 	_DIAGASSERT(fd != -1);
77 	_DIAGASSERT(list != NULL);
78 
79 	if (pread(fd, &exec, sizeof(exec), (off_t)0) != sizeof(exec) ||
80 	    N_BADMAG(exec) || fstat(fd, &st) < 0)
81 		return (-1);
82 
83 	symoff = N_SYMOFF(exec);
84 	symsize = (size_t)exec.a_syms;
85 	stroff = symoff + symsize;
86 
87 	/* Check for files too large to mmap. */
88 	if (st.st_size - stroff > SIZE_T_MAX) {
89 		errno = EFBIG;
90 		return (-1);
91 	}
92 	/*
93 	 * Map string table into our address space.  This gives us
94 	 * an easy way to randomly access all the strings, without
95 	 * making the memory allocation permanent as with malloc/free
96 	 * (i.e., munmap will return it to the system).
97 	 */
98 	strsize = (size_t)(st.st_size - stroff);
99 	strtab = mmap(NULL, strsize, PROT_READ, MAP_PRIVATE|MAP_FILE,
100 	    fd, stroff);
101 	if (strtab == (char *)-1)
102 		return (-1);
103 	/*
104 	 * clean out any left-over information for all valid entries.
105 	 * Type and value defined to be 0 if not found; historical
106 	 * versions cleared other and desc as well.  Also figure out
107 	 * the largest string length so don't read any more of the
108 	 * string table than we have to.
109 	 *
110 	 * XXX clearing anything other than n_type and n_value violates
111 	 * the semantics given in the man page.
112 	 */
113 	nent = 0;
114 	for (p = list; !ISLAST(p); ++p) {
115 		p->n_type = 0;
116 		p->n_other = 0;
117 		p->n_desc = 0;
118 		p->n_value = 0;
119 		++nent;
120 	}
121 	if (lseek(fd, symoff, SEEK_SET) == -1)
122 		return (-1);
123 
124 	while (symsize > 0) {
125 		cc = MIN(symsize, sizeof(nbuf));
126 		if (read(fd, nbuf, cc) != (ssize_t) cc)
127 			break;
128 		symsize -= cc;
129 		for (s = nbuf; cc > 0; ++s, cc -= sizeof(*s)) {
130 			long soff = s->n_un.n_strx;
131 
132 			if (soff == 0 || (s->n_type & N_STAB) != 0)
133 				continue;
134 			for (p = list; !ISLAST(p); p++)
135 				if (!strcmp(&strtab[(size_t)soff],
136 				    p->n_un.n_name)) {
137 					p->n_value = s->n_value;
138 					p->n_type = s->n_type;
139 					p->n_desc = s->n_desc;
140 					p->n_other = s->n_other;
141 					if (--nent <= 0)
142 						break;
143 				}
144 		}
145 	}
146 	munmap(strtab, strsize);
147 	return (nent);
148 }
149 #endif /* NLIST_AOUT */
150