xref: /netbsd-src/lib/libc/gen/nlist_aout.c (revision bada23909e740596d0a3785a73bd3583a9807fb8)
1 /*	$NetBSD: nlist_aout.c,v 1.8 1998/11/13 10:26:19 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 1.8 1998/11/13 10:26:19 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 <errno.h>
53 #include <stdio.h>
54 #include <string.h>
55 #include <unistd.h>
56 #include <a.out.h>			/* for 'struct nlist' declaration */
57 
58 #include "nlist_private.h"
59 
60 #ifdef NLIST_AOUT
61 int
62 __fdnlist_aout(fd, list)
63 	int fd;
64 	struct nlist *list;
65 {
66 	struct nlist *p, *s;
67 	char *strtab;
68 	off_t stroff, symoff;
69 	int nent;
70 	size_t strsize, symsize, cc;
71 	struct nlist nbuf[1024];
72 	struct exec exec;
73 	struct stat st;
74 
75 	if (pread(fd, &exec, sizeof(exec), (off_t)0) != sizeof(exec) ||
76 	    N_BADMAG(exec) || fstat(fd, &st) < 0)
77 		return (-1);
78 
79 	symoff = N_SYMOFF(exec);
80 	symsize = (size_t)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 = (size_t)(st.st_size - stroff);
95 	strtab = mmap(NULL, strsize, PROT_READ, MAP_COPY|MAP_FILE,
96 	    fd, stroff);
97 	if (strtab == (char *)-1)
98 		return (-1);
99 	/*
100 	 * clean out any left-over information for all valid entries.
101 	 * Type and value defined to be 0 if not found; historical
102 	 * versions cleared other and desc as well.  Also figure out
103 	 * the largest string length so don't read any more of the
104 	 * string table than we have to.
105 	 *
106 	 * XXX clearing anything other than n_type and n_value violates
107 	 * the semantics given in the man page.
108 	 */
109 	nent = 0;
110 	for (p = list; !ISLAST(p); ++p) {
111 		p->n_type = 0;
112 		p->n_other = 0;
113 		p->n_desc = 0;
114 		p->n_value = 0;
115 		++nent;
116 	}
117 	if (lseek(fd, symoff, SEEK_SET) == -1)
118 		return (-1);
119 
120 	while (symsize > 0) {
121 		cc = MIN(symsize, sizeof(nbuf));
122 		if (read(fd, nbuf, cc) != cc)
123 			break;
124 		symsize -= cc;
125 		for (s = nbuf; cc > 0; ++s, cc -= sizeof(*s)) {
126 			long soff = s->n_un.n_strx;
127 
128 			if (soff == 0 || (s->n_type & N_STAB) != 0)
129 				continue;
130 			for (p = list; !ISLAST(p); p++)
131 				if (!strcmp(&strtab[(size_t)soff],
132 				    p->n_un.n_name)) {
133 					p->n_value = s->n_value;
134 					p->n_type = s->n_type;
135 					p->n_desc = s->n_desc;
136 					p->n_other = s->n_other;
137 					if (--nent <= 0)
138 						break;
139 				}
140 		}
141 	}
142 	munmap(strtab, strsize);
143 	return (nent);
144 }
145 #endif /* NLIST_AOUT */
146