xref: /netbsd-src/lib/libc/gen/nlist.c (revision 81b108b45f75f89f1e3ffad9fb6f074e771c0935)
1 /*	$NetBSD: nlist.c,v 1.7 1996/05/16 20:49:20 cgd Exp $	*/
2 
3 /*
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  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 by the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #if defined(LIBC_SCCS) && !defined(lint)
37 #if 0
38 static char sccsid[] = "@(#)nlist.c	8.1 (Berkeley) 6/4/93";
39 #else
40 static char rcsid[] = "$NetBSD: nlist.c,v 1.7 1996/05/16 20:49:20 cgd Exp $";
41 #endif
42 #endif /* LIBC_SCCS and not lint */
43 
44 #ifdef __alpha__
45 #define		DO_ECOFF
46 #else
47 #define		DO_AOUT
48 #endif
49 
50 #if defined(DO_AOUT) + defined(DO_ECOFF) != 1
51 	ERROR: NOT PROPERLY CONFIGURED
52 #endif
53 
54 #include <sys/param.h>
55 #include <sys/mman.h>
56 #include <sys/stat.h>
57 #include <sys/file.h>
58 
59 #include <errno.h>
60 #include <a.out.h>
61 #ifdef DO_ECOFF
62 #include <sys/exec_ecoff.h>
63 #endif
64 #include <stdio.h>
65 #include <string.h>
66 #include <unistd.h>
67 
68 int
69 nlist(name, list)
70 	const char *name;
71 	struct nlist *list;
72 {
73 	int fd, n;
74 
75 	fd = open(name, O_RDONLY, 0);
76 	if (fd < 0)
77 		return (-1);
78 	n = __fdnlist(fd, list);
79 	(void)close(fd);
80 	return (n);
81 }
82 
83 #define	ISLAST(p)	(p->n_un.n_name == 0 || p->n_un.n_name[0] == 0)
84 
85 #ifdef DO_AOUT
86 int
87 __fdnlist(fd, list)
88 	register int fd;
89 	register struct nlist *list;
90 {
91 	register struct nlist *p, *s;
92 	register caddr_t strtab;
93 	register off_t stroff, symoff;
94 	register u_long symsize;
95 	register int nent, cc;
96 	size_t strsize;
97 	struct nlist nbuf[1024];
98 	struct exec exec;
99 	struct stat st;
100 
101 	if (lseek(fd, (off_t)0, SEEK_SET) == -1 ||
102 	    read(fd, &exec, sizeof(exec)) != sizeof(exec) ||
103 	    N_BADMAG(exec) || fstat(fd, &st) < 0)
104 		return (-1);
105 
106 	symoff = N_SYMOFF(exec);
107 	symsize = exec.a_syms;
108 	stroff = symoff + symsize;
109 
110 	/* Check for files too large to mmap. */
111 	if (st.st_size - stroff > SIZE_T_MAX) {
112 		errno = EFBIG;
113 		return (-1);
114 	}
115 	/*
116 	 * Map string table into our address space.  This gives us
117 	 * an easy way to randomly access all the strings, without
118 	 * making the memory allocation permanent as with malloc/free
119 	 * (i.e., munmap will return it to the system).
120 	 */
121 	strsize = st.st_size - stroff;
122 	strtab = mmap(NULL, (size_t)strsize, PROT_READ, 0, fd, stroff);
123 	if (strtab == (char *)-1)
124 		return (-1);
125 	/*
126 	 * clean out any left-over information for all valid entries.
127 	 * Type and value defined to be 0 if not found; historical
128 	 * versions cleared other and desc as well.  Also figure out
129 	 * the largest string length so don't read any more of the
130 	 * string table than we have to.
131 	 *
132 	 * XXX clearing anything other than n_type and n_value violates
133 	 * the semantics given in the man page.
134 	 */
135 	nent = 0;
136 	for (p = list; !ISLAST(p); ++p) {
137 		p->n_type = 0;
138 		p->n_other = 0;
139 		p->n_desc = 0;
140 		p->n_value = 0;
141 		++nent;
142 	}
143 	if (lseek(fd, symoff, SEEK_SET) == -1)
144 		return (-1);
145 
146 	while (symsize > 0) {
147 		cc = MIN(symsize, sizeof(nbuf));
148 		if (read(fd, nbuf, cc) != cc)
149 			break;
150 		symsize -= cc;
151 		for (s = nbuf; cc > 0; ++s, cc -= sizeof(*s)) {
152 			register int soff = s->n_un.n_strx;
153 
154 			if (soff == 0 || (s->n_type & N_STAB) != 0)
155 				continue;
156 			for (p = list; !ISLAST(p); p++)
157 				if (!strcmp(&strtab[soff], p->n_un.n_name)) {
158 					p->n_value = s->n_value;
159 					p->n_type = s->n_type;
160 					p->n_desc = s->n_desc;
161 					p->n_other = s->n_other;
162 					if (--nent <= 0)
163 						break;
164 				}
165 		}
166 	}
167 	munmap(strtab, strsize);
168 	return (nent);
169 }
170 #endif /* DO_AOUT */
171 
172 #ifdef DO_ECOFF
173 #define check(off, size)	((off < 0) || (off + size > mappedsize))
174 #define	BAD			do { rv = -1; goto out; } while (0)
175 #define	BADUNMAP		do { rv = -1; goto unmap; } while (0)
176 
177 int
178 __fdnlist(fd, list)
179 	register int fd;
180 	register struct nlist *list;
181 {
182 	struct nlist *p;
183 	struct ecoff_exechdr *exechdrp;
184 	struct ecoff_symhdr *symhdrp;
185 	struct ecoff_extsym *esyms;
186 	struct stat st;
187 	char *mappedfile;
188 	size_t mappedsize;
189 	u_long symhdroff, extstroff;
190 	u_int symhdrsize;
191 	int rv, nent;
192 	long i, nesyms;
193 
194 	rv = -3;
195 
196 	if (fstat(fd, &st) < 0)
197 		BAD;
198 	if (st.st_size > SIZE_T_MAX) {
199 		errno = EFBIG;
200 		BAD;
201 	}
202 	mappedsize = st.st_size;
203 	mappedfile = mmap(NULL, mappedsize, PROT_READ, 0, fd, 0);
204 	if (mappedfile == (char *)-1)
205 		BAD;
206 
207 	if (check(0, sizeof *exechdrp))
208 		BADUNMAP;
209 	exechdrp = (struct ecoff_exechdr *)&mappedfile[0];
210 
211 	if (ECOFF_BADMAG(exechdrp))
212 		BADUNMAP;
213 
214 	symhdroff = exechdrp->f.f_symptr;
215 	symhdrsize = exechdrp->f.f_nsyms;
216 
217 	if (check(symhdroff, sizeof *symhdrp) ||
218 	    sizeof *symhdrp != symhdrsize)
219 		BADUNMAP;
220 	symhdrp = (struct ecoff_symhdr *)&mappedfile[symhdroff];
221 
222 	nesyms = symhdrp->esymMax;
223 	if (check(symhdrp->cbExtOffset, nesyms * sizeof *esyms))
224 		BADUNMAP;
225 	esyms = (struct ecoff_extsym *)&mappedfile[symhdrp->cbExtOffset];
226 	extstroff = symhdrp->cbSsExtOffset;
227 
228 	/*
229 	 * clean out any left-over information for all valid entries.
230 	 * Type and value defined to be 0 if not found; historical
231 	 * versions cleared other and desc as well.
232 	 *
233 	 * XXX clearing anything other than n_type and n_value violates
234 	 * the semantics given in the man page.
235 	 */
236 	nent = 0;
237 	for (p = list; !ISLAST(p); ++p) {
238 		p->n_type = 0;
239 		p->n_other = 0;
240 		p->n_desc = 0;
241 		p->n_value = 0;
242 		++nent;
243 	}
244 
245 	for (i = 0; i < nesyms; i++) {
246 		for (p = list; !ISLAST(p); p++) {
247 			char *nlistname;
248 			char *symtabname;
249 
250 			nlistname = p->n_un.n_name;
251 			if (*nlistname == '_')
252 				nlistname++;
253 			symtabname =
254 			    &mappedfile[extstroff + esyms[i].es_strindex];
255 
256 			if (!strcmp(symtabname, nlistname)) {
257 				p->n_value = esyms[i].es_value;
258 				p->n_type = N_EXT;		/* XXX */
259 				p->n_desc = 0;			/* XXX */
260 				p->n_other = 0;			/* XXX */
261 				if (--nent <= 0)
262 					break;
263 			}
264 		}
265 	}
266 	rv = nent;
267 
268 unmap:
269 	munmap(mappedfile, mappedsize);
270 out:
271 	return (rv);
272 }
273 #endif /* DO_ECOFF */
274