/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*      Copyright (c) 1988 AT&T */
/*        All Rights Reserved   */


/*
 * Copyright (c) 1998 by Sun Microsystems, Inc.
 * All rights reserved.
 */

#include "libelf.h"
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <nlist.h>
#include "syms.h"
#include "gelf.h"

#undef n_name           /* This undef is to handle a #define in syms.h */
                        /* which conflicts with the member nlist->n_name */
                        /* as defined in nlist.h */


#define SPACE 100               /* number of symbols read at a time */
#define ISELF (strncmp(magic_buf, ELFMAG, SELFMAG) == 0)


int
end_elf_job(int fd, Elf * elfdes)
{
        (void) elf_end(elfdes);
        (void) close(fd);
        return (-1);
}


int
_elf_nlist(int fd, struct nlist * list)
{
        Elf        *elfdes;     /* ELF descriptor */
        GElf_Ehdr  ehdr;        /* ELF Ehdr */
        GElf_Shdr  s_buf;       /* buffer storing section header */
        Elf_Data   *symdata;    /* buffer points to symbol table */
        Elf_Scn    *secidx = 0; /* index of the section header table */
        GElf_Sym   sym;         /* buffer storing one symbol information */
        unsigned   strtab;      /* index of symbol name in string table */
        long       count;       /* number of symbols */
        long       ii;          /* loop control */

        if (elf_version(EV_CURRENT) == EV_NONE) {
                (void) close(fd);
                return (-1);
        }
        elfdes = elf_begin(fd, ELF_C_READ, (Elf *)0);
        if (gelf_getehdr(elfdes, &ehdr) == 0)
                return (end_elf_job(fd, elfdes));

        while ((secidx = elf_nextscn(elfdes, secidx)) != 0) {
                if ((gelf_getshdr(secidx, &s_buf)) == 0)
                        return (end_elf_job(fd, elfdes));
                if (s_buf.sh_type != SHT_SYMTAB) /* not symbol table */
                        continue;
                symdata = elf_getdata(secidx, (Elf_Data *)0);
                if (symdata == 0)
                        return (end_elf_job(fd, elfdes));
                if (symdata->d_size == 0)
                        break;
                strtab = s_buf.sh_link;
                count = symdata->d_size / s_buf.sh_entsize;
                for (ii = 1; ii < count; ++ii) {
                        struct nlist *p;
                        register char *name;
                        /* LINTED */
                        (void) gelf_getsym(symdata, (int)ii, &sym);
                        name = elf_strptr(elfdes, strtab, (size_t)sym.st_name);
                        if (name == 0)
                                continue;
                        for (p = list; p->n_name && p->n_name[0]; ++p) {
                                if (strcmp(p->n_name, name))
                                        continue;
                                p->n_value = (long)sym.st_value;
                                p->n_type = GELF_ST_TYPE(sym.st_info);
                                p->n_scnum = sym.st_shndx;
                                break;
                        }
                }
                break;
                /*
                 * Currently there is only one symbol table section
                 * in an object file, but this restriction may be
                 * relaxed in the future.
                 */
        }
        (void) elf_end(elfdes);
        (void) close(fd);
        return (0);
}

int
nlist(const char * name, struct nlist * list)
{
        register struct nlist *p;
        char magic_buf[EI_NIDENT];
        int fd;

        for (p = list; p->n_name && p->n_name[0]; p++) { /* n_name can be ptr */
                p->n_type = 0;
                p->n_value = 0L;
                p->n_scnum = 0;
                p->n_sclass = 0;
                p->n_numaux = 0;
        }

        if ((fd = open(name, 0)) < 0)
                return (-1);
        if (read(fd, magic_buf, EI_NIDENT) == -1) {
                (void) close(fd);
                return (-1);
        }

        if (lseek(fd, 0L, 0) == -1L) {  /* rewind to beginning of object file */
                (void) close(fd);
                return (-1);
        }

#ifndef _LP64
        if (ISELF && (magic_buf[EI_CLASS] == ELFCLASS32))
#else
        if (ISELF)              /* 64-bit case handles both Elf32 and Elf64 */
#endif
                return (_elf_nlist(fd, list));
        else {
                (void) close(fd);
                return (-1);
        }
}