1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License, Version 1.0 only
6 * (the "License"). You may not use this file except in compliance
7 * with the License.
8 *
9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10 * or http://www.opensolaris.org/os/licensing.
11 * See the License for the specific language governing permissions
12 * and limitations under the License.
13 *
14 * When distributing Covered Code, include this CDDL HEADER in each
15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16 * If applicable, add the following below this CDDL HEADER, with the
17 * fields enclosed by brackets "[]" replaced with your own identifying
18 * information: Portions Copyright [yyyy] [name of copyright owner]
19 *
20 * CDDL HEADER END
21 */
22 /* Copyright (c) 1988 AT&T */
23 /* All Rights Reserved */
24
25
26 /*
27 * Copyright (c) 1998 by Sun Microsystems, Inc.
28 * All rights reserved.
29 */
30
31 #pragma ident "%Z%%M% %I% %E% SMI" /* SVr4.0 1.13 */
32
33 #include "libelf.h"
34 #include <unistd.h>
35 #include <fcntl.h>
36 #include <string.h>
37 #include <nlist.h>
38 #include <note.h>
39 #include "syms.h"
40 #include "gelf.h"
41
42 #undef n_name /* This undef is to handle a #define in syms.h */
43 /* which conflicts with the member nlist->n_name */
44 /* as defined in nlist.h */
45
46
47 #define SPACE 100 /* number of symbols read at a time */
48 #define ISELF (strncmp(magic_buf, ELFMAG, SELFMAG) == 0)
49
50
51 int
end_elf_job(int fd,Elf * elfdes)52 end_elf_job(int fd, Elf * elfdes)
53 {
54 (void) elf_end(elfdes);
55 (void) close(fd);
56 return (-1);
57 }
58
59
60 int
_elf_nlist(int fd,struct nlist * list)61 _elf_nlist(int fd, struct nlist * list)
62 {
63 Elf *elfdes; /* ELF descriptor */
64 GElf_Ehdr ehdr; /* ELF Ehdr */
65 GElf_Shdr s_buf; /* buffer storing section header */
66 Elf_Data *symdata; /* buffer points to symbol table */
67 Elf_Scn *secidx = 0; /* index of the section header table */
68 GElf_Sym sym; /* buffer storing one symbol information */
69 unsigned strtab; /* index of symbol name in string table */
70 long count; /* number of symbols */
71 long ii; /* loop control */
72
73 if (elf_version(EV_CURRENT) == EV_NONE) {
74 (void) close(fd);
75 return (-1);
76 }
77 elfdes = elf_begin(fd, ELF_C_READ, (Elf *)0);
78 if (gelf_getehdr(elfdes, &ehdr) == 0)
79 return (end_elf_job(fd, elfdes));
80
81 while ((secidx = elf_nextscn(elfdes, secidx)) != 0) {
82 if ((gelf_getshdr(secidx, &s_buf)) == 0)
83 return (end_elf_job(fd, elfdes));
84 if (s_buf.sh_type != SHT_SYMTAB) /* not symbol table */
85 continue;
86 symdata = elf_getdata(secidx, (Elf_Data *)0);
87 if (symdata == 0)
88 return (end_elf_job(fd, elfdes));
89 if (symdata->d_size == 0)
90 break;
91 strtab = s_buf.sh_link;
92 count = symdata->d_size / s_buf.sh_entsize;
93 for (ii = 1; ii < count; ++ii) {
94 struct nlist *p;
95 register char *name;
96 /* LINTED */
97 (void) gelf_getsym(symdata, (int)ii, &sym);
98 name = elf_strptr(elfdes, strtab, (size_t)sym.st_name);
99 if (name == 0)
100 continue;
101 for (p = list; p->n_name && p->n_name[0]; ++p) {
102 if (strcmp(p->n_name, name))
103 continue;
104 p->n_value = (long)sym.st_value;
105 p->n_type = GELF_ST_TYPE(sym.st_info);
106 p->n_scnum = sym.st_shndx;
107 break;
108 }
109 }
110 break;
111 /*
112 * Currently there is only one symbol table section
113 * in an object file, but this restriction may be
114 * relaxed in the future.
115 */
116 }
117 (void) elf_end(elfdes);
118 (void) close(fd);
119 return (0);
120 }
121
122
123 NOTE(SCHEME_PROTECTS_DATA("user provides buffers", nlist))
124
125 int
nlist(const char * name,struct nlist * list)126 nlist(const char * name, struct nlist * list)
127 {
128 register struct nlist *p;
129 char magic_buf[EI_NIDENT];
130 int fd;
131
132 for (p = list; p->n_name && p->n_name[0]; p++) { /* n_name can be ptr */
133 p->n_type = 0;
134 p->n_value = 0L;
135 p->n_scnum = 0;
136 p->n_sclass = 0;
137 p->n_numaux = 0;
138 }
139
140 if ((fd = open(name, 0)) < 0)
141 return (-1);
142 if (read(fd, magic_buf, EI_NIDENT) == -1) {
143 (void) close(fd);
144 return (-1);
145 }
146
147 if (lseek(fd, 0L, 0) == -1L) { /* rewind to beginning of object file */
148 (void) close(fd);
149 return (-1);
150 }
151
152 #ifndef _LP64
153 if (ISELF && (magic_buf[EI_CLASS] == ELFCLASS32))
154 #else
155 if (ISELF) /* 64-bit case handles both Elf32 and Elf64 */
156 #endif
157 return (_elf_nlist(fd, list));
158 else {
159 (void) close(fd);
160 return (-1);
161 }
162 }
163