xref: /netbsd-src/lib/libc/gen/nlist_coff.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /* $NetBSD: nlist_coff.c,v 1.8 2009/08/21 08:42:02 he 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 1.8 2009/08/21 08:42:02 he 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 <nlist.h>
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	BAD		do { rv = -1; goto out; } while (/*CONSTCOND*/0)
62 #define	BADUNMAP	do { rv = -1; goto unmap; } while (/*CONSTCOND*/0)
63 
64 #define ES_LEN 18
65 struct coff_extsym {
66 	union {
67 		char u_name[8];
68 		struct {
69 			int u_zero;
70 			int u_offset;
71 		} s;
72 	} u;
73 	int32_t es_value;
74 	int16_t es_scnum;
75 	int16_t es_type;
76 	int8_t es_class;
77 	int8_t es_numaux;
78 };
79 #define es_name u.u_name
80 #define es_zero u.s.u_zero
81 #define es_offset u.s.u_offset
82 
83 int
84 __fdnlist_coff(fd, list)
85 	int fd;
86 	struct nlist *list;
87 {
88 	struct nlist *p;
89 	struct coff_filehdr *filehdrp;
90 	struct stat st;
91 	char *mappedfile;
92 	size_t mappedsize;
93 	u_long symoff, extstroff;
94 	int rv, nent;
95 	long i, nesyms;
96 
97 	_DIAGASSERT(fd != -1);
98 	_DIAGASSERT(list != NULL);
99 
100 	rv = -1;
101 
102 	/*
103 	 * If we can't fstat() the file, something bad is going on.
104 	 */
105 	if (fstat(fd, &st) < 0)
106 		BAD;
107 
108 	/*
109 	 * Map the file in its entirety.
110 	 */
111 	if ((uintmax_t)st.st_size > (uintmax_t)SIZE_T_MAX) {
112 		errno = EFBIG;
113 		BAD;
114 	}
115 	mappedsize = st.st_size;
116 	mappedfile = mmap(NULL, mappedsize, PROT_READ, MAP_PRIVATE|MAP_FILE,
117 	    fd, 0);
118 	if (mappedfile == (char *)-1)
119 		BAD;
120 
121 	/*
122 	 * Make sure we can access the executable's header
123 	 * directly, and make sure we recognize the executable
124 	 * as an COFF binary.
125 	 */
126 	if (mappedsize < sizeof (struct coff_filehdr))
127 		BADUNMAP;
128 	filehdrp = (struct coff_filehdr *)&mappedfile[0];
129 
130 	if (COFF_BADMAG(filehdrp))
131 		BADUNMAP;
132 
133 	/*
134 	 * Find the symbol list.
135 	 */
136 	symoff = filehdrp->f_symptr;
137 	nesyms = filehdrp->f_nsyms;
138 
139 	if (symoff + ES_LEN * nesyms > mappedsize)
140 		BADUNMAP;
141 	extstroff = symoff + ES_LEN * nesyms;
142 
143 	nent = 0;
144 	for (p = list; !ISLAST(p); ++p) {
145 		p->n_type = 0;
146 		p->n_other = 0;
147 		p->n_desc = 0;
148 		p->n_value = 0;
149 		++nent;
150 	}
151 
152 	for (i = 0; i < nesyms; i++) {
153 		char *symtabname;
154 		const char *nlistname;
155 		struct coff_extsym esym;
156 		char name[10];
157 
158 		memcpy(&esym, &mappedfile[symoff + ES_LEN * i], ES_LEN);
159 		if (esym.es_numaux != 0) {
160 			i += esym.es_numaux;	/* XXX Skip aux entry */
161 			continue;
162 		}
163 
164 		if (esym.es_zero != 0) {
165 			memcpy(name, esym.es_name, 8);
166 			name[8] = 0;
167 			symtabname = name;
168 		} else if (esym.es_offset != 0)
169 			symtabname = &mappedfile[extstroff + esym.es_offset];
170 		else
171 			continue;
172 
173 		for (p = list; !ISLAST(p); p++) {
174 			nlistname = N_NAME(p);
175 			if (!strcmp(symtabname, nlistname)) {
176 				/*
177 				 * Translate (roughly) from COFF to nlist
178 				 */
179 				p->n_value = esym.es_value;
180 				p->n_type = N_EXT;		/* XXX */
181 				p->n_desc = 0;			/* XXX */
182 				p->n_other = 0;			/* XXX */
183 
184 				if (--nent <= 0)
185 					goto done;
186 				break;	/* into next run of outer loop */
187 			}
188 		}
189 	}
190 
191 done:
192 	rv = nent;
193 unmap:
194 	munmap(mappedfile, mappedsize);
195 out:
196 	return (rv);
197 }
198 
199 #endif /* NLIST_COFF */
200