xref: /netbsd/lib/libc/gen/nlist_coff.c (revision bf9ec67e)
1 /* $NetBSD: nlist_coff.c,v 1.4 2000/06/14 17:25:01 cgd Exp $ */
2 
3 /*
4  * Copyright (c) 1996 Christopher G. Demetriou
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *          This product includes software developed for the
18  *          NetBSD Project.  See http://www.netbsd.org/ for
19  *          information about NetBSD.
20  * 4. The name of the author may not be used to endorse or promote products
21  *    derived from this software without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
24  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
25  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
26  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
27  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
28  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
29  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
30  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
31  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
32  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
33  *
34  * <<Id: LICENSE,v 1.2 2000/06/14 15:57:33 cgd Exp>>
35  */
36 
37 #include <sys/cdefs.h>
38 #if defined(LIBC_SCCS) && !defined(lint)
39 __RCSID("$NetBSD: nlist_coff.c,v 1.4 2000/06/14 17:25:01 cgd Exp $");
40 #endif /* LIBC_SCCS and not lint */
41 
42 #include "namespace.h"
43 #include <sys/param.h>
44 #include <sys/mman.h>
45 #include <sys/stat.h>
46 #include <sys/file.h>
47 
48 #include <assert.h>
49 #include <errno.h>
50 #include <stdio.h>
51 #include <string.h>
52 #include <unistd.h>
53 #include <a.out.h>			/* for 'struct nlist' declaration */
54 
55 #include "nlist_private.h"
56 #ifdef NLIST_COFF
57 #include <sys/exec_coff.h>
58 #endif
59 
60 #ifdef NLIST_COFF
61 #define	check(off, size)	((off < 0) || (off + size > mappedsize))
62 #define	BAD			do { rv = -1; goto out; } while (/*CONSTCOND*/0)
63 #define	BADUNMAP		do { rv = -1; goto unmap; } while (/*CONSTCOND*/0)
64 
65 #define ES_LEN 18
66 struct coff_extsym {
67 	union {
68 		char u_name[8];
69 		struct {
70 			int u_zero;
71 			int u_offset;
72 		} s;
73 	} u;
74 	int32_t es_value;
75 	int16_t es_scnum;
76 	int16_t es_type;
77 	int8_t es_class;
78 	int8_t es_numaux;
79 };
80 #define es_name u.u_name
81 #define es_zero u.s.u_zero
82 #define es_offset u.s.u_offset
83 
84 int
85 __fdnlist_coff(fd, list)
86 	int fd;
87 	struct nlist *list;
88 {
89 	struct nlist *p;
90 	struct coff_filehdr *filehdrp;
91 	struct stat st;
92 	char *mappedfile;
93 	size_t mappedsize;
94 	u_long symoff, extstroff;
95 	int rv, nent;
96 	long i, nesyms;
97 
98 	_DIAGASSERT(fd != -1);
99 	_DIAGASSERT(list != NULL);
100 
101 	rv = -1;
102 
103 	/*
104 	 * If we can't fstat() the file, something bad is going on.
105 	 */
106 	if (fstat(fd, &st) < 0)
107 		BAD;
108 
109 	/*
110 	 * Map the file in its entirety.
111 	 */
112 	if (st.st_size > SIZE_T_MAX) {
113 		errno = EFBIG;
114 		BAD;
115 	}
116 	mappedsize = st.st_size;
117 	mappedfile = mmap(NULL, mappedsize, PROT_READ, MAP_PRIVATE|MAP_FILE,
118 	    fd, 0);
119 	if (mappedfile == (char *)-1)
120 		BAD;
121 
122 	/*
123 	 * Make sure we can access the executable's header
124 	 * directly, and make sure the recognize the executable
125 	 * as an COFF binary.
126 	 */
127 	if (check(0, sizeof *filehdrp))
128 		BADUNMAP;
129 	filehdrp = (struct coff_filehdr *)&mappedfile[0];
130 
131 	if (COFF_BADMAG(filehdrp))
132 		BADUNMAP;
133 
134 	/*
135 	 * Find the symbol list.
136 	 */
137 	symoff = filehdrp->f_symptr;
138 	nesyms = filehdrp->f_nsyms;
139 
140 	if (check(symoff, ES_LEN * nesyms))
141 		BADUNMAP;
142 	extstroff = symoff + ES_LEN * nesyms;
143 
144 	nent = 0;
145 	for (p = list; !ISLAST(p); ++p) {
146 		p->n_type = 0;
147 		p->n_other = 0;
148 		p->n_desc = 0;
149 		p->n_value = 0;
150 		++nent;
151 	}
152 
153 	for (i = 0; i < nesyms; i++) {
154 		char *symtabname;
155 		char *nlistname;
156 		struct coff_extsym esym;
157 		char name[10];
158 
159 		memcpy(&esym, &mappedfile[symoff + ES_LEN * i], ES_LEN);
160 		if (esym.es_numaux != 0) {
161 			i += esym.es_numaux;	/* XXX Skip aux entry */
162 			continue;
163 		}
164 
165 		if (esym.es_zero != 0) {
166 			memcpy(name, esym.es_name, 8);
167 			name[8] = 0;
168 			symtabname = name;
169 		} else if (esym.es_offset != 0)
170 			symtabname = &mappedfile[extstroff + esym.es_offset];
171 		else
172 			continue;
173 
174 		for (p = list; !ISLAST(p); p++) {
175 			nlistname = p->n_un.n_name;
176 			if (!strcmp(symtabname, nlistname)) {
177 				/*
178 				 * Translate (roughly) from COFF to nlist
179 				 */
180 				p->n_value = esym.es_value;
181 				p->n_type = N_EXT;		/* XXX */
182 				p->n_desc = 0;			/* XXX */
183 				p->n_other = 0;			/* XXX */
184 
185 				if (--nent <= 0)
186 					goto done;
187 				break;	/* into next run of outer loop */
188 			}
189 		}
190 	}
191 
192 done:
193 	rv = nent;
194 unmap:
195 	munmap(mappedfile, mappedsize);
196 out:
197 	return (rv);
198 }
199 
200 #endif /* NLIST_COFF */
201