usr/src/cmd/sgs/libelf/misc/nlist.c

   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 #include "libelf.h"
  32 #include <unistd.h>
  33 #include <fcntl.h>
  34 #include <string.h>
  35 #include <nlist.h>
  36 #include "syms.h"
  37 #include "gelf.h"
  38
  39 #undef n_name           /* This undef is to handle a #define in syms.h */
  40                         /* which conflicts with the member nlist->n_name */
  41                         /* as defined in nlist.h */
  42
  43
  44 #define SPACE 100               /* number of symbols read at a time */
  45 #define ISELF (strncmp(magic_buf, ELFMAG, SELFMAG) == 0)
  46
  47
  48 int
  49 end_elf_job(int fd, Elf * elfdes)
  50 {
  51         (void) elf_end(elfdes);
  52         (void) close(fd);
  53         return (-1);
  54 }
  55
  56
  57 int
  58 _elf_nlist(int fd, struct nlist * list)
  59 {
  60         Elf        *elfdes;     /* ELF descriptor */
  61         GElf_Ehdr  ehdr;        /* ELF Ehdr */
  62         GElf_Shdr  s_buf;       /* buffer storing section header */
  63         Elf_Data   *symdata;    /* buffer points to symbol table */
  64         Elf_Scn    *secidx = 0; /* index of the section header table */
  65         GElf_Sym   sym;         /* buffer storing one symbol information */
  66         unsigned   strtab;      /* index of symbol name in string table */
  67         long       count;       /* number of symbols */
  68         long       ii;          /* loop control */
  69
  70         if (elf_version(EV_CURRENT) == EV_NONE) {
  71                 (void) close(fd);
  72                 return (-1);
  73         }
  74         elfdes = elf_begin(fd, ELF_C_READ, (Elf *)0);
  75         if (gelf_getehdr(elfdes, &ehdr) == 0)
  76                 return (end_elf_job(fd, elfdes));
  77
  78         while ((secidx = elf_nextscn(elfdes, secidx)) != 0) {
  79                 if ((gelf_getshdr(secidx, &s_buf)) == 0)
  80                         return (end_elf_job(fd, elfdes));
  81                 if (s_buf.sh_type != SHT_SYMTAB) /* not symbol table */
  82                         continue;
  83                 symdata = elf_getdata(secidx, (Elf_Data *)0);
  84                 if (symdata == 0)
  85                         return (end_elf_job(fd, elfdes));
  86                 if (symdata->d_size == 0)
  87                         break;
  88                 strtab = s_buf.sh_link;
  89                 count = symdata->d_size / s_buf.sh_entsize;
  90                 for (ii = 1; ii < count; ++ii) {
  91                         struct nlist *p;
  92                         register char *name;
  93                         /* LINTED */
  94                         (void) gelf_getsym(symdata, (int)ii, &sym);
  95                         name = elf_strptr(elfdes, strtab, (size_t)sym.st_name);
  96                         if (name == 0)
  97                                 continue;
  98                         for (p = list; p->n_name && p->n_name[0]; ++p) {
  99                                 if (strcmp(p->n_name, name))
 100                                         continue;
 101                                 p->n_value = (long)sym.st_value;
 102                                 p->n_type = GELF_ST_TYPE(sym.st_info);
 103                                 p->n_scnum = sym.st_shndx;
 104                                 break;
 105                         }
 106                 }
 107                 break;
 108                 /*
 109                  * Currently there is only one symbol table section
 110                  * in an object file, but this restriction may be
 111                  * relaxed in the future.
 112                  */
 113         }
 114         (void) elf_end(elfdes);
 115         (void) close(fd);
 116         return (0);
 117 }
 118
 119 int
 120 nlist(const char * name, struct nlist * list)
 121 {
 122         register struct nlist *p;
 123         char magic_buf[EI_NIDENT];
 124         int fd;
 125
 126         for (p = list; p->n_name && p->n_name[0]; p++) { /* n_name can be ptr */
 127                 p->n_type = 0;
 128                 p->n_value = 0L;
 129                 p->n_scnum = 0;
 130                 p->n_sclass = 0;
 131                 p->n_numaux = 0;
 132         }
 133
 134         if ((fd = open(name, O_RDONLY)) < 0)
 135                 return (-1);
 136         if (read(fd, magic_buf, EI_NIDENT) == -1) {
 137                 (void) close(fd);
 138                 return (-1);
 139         }
 140
 141         if (lseek(fd, 0L, 0) == -1L) {  /* rewind to beginning of object file */
 142                 (void) close(fd);
 143                 return (-1);
 144         }
 145
 146 #ifndef _LP64
 147         if (ISELF && (magic_buf[EI_CLASS] == ELFCLASS32))
 148 #else
 149         if (ISELF)              /* 64-bit case handles both Elf32 and Elf64 */
 150 #endif
 151                 return (_elf_nlist(fd, list));
 152         else {
 153                 (void) close(fd);
 154                 return (-1);
 155         }
 156 }