minix/commands/swifi/read_nlist.c
2008-10-02 13:45:46 +00:00

329 lines
7.2 KiB
C

/*
read_nlist.c
Read the symbol table of an executable into memory.
Created: Mar 6, 1992 by Philip Homburg
*/
#include <sys/types.h>
#include <assert.h>
#include <a.out.h>
#include <errno.h>
#include <fcntl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "extra.h"
#define USE_OLD_NLIST 1
static u16_t le16 _ARGS(( u16_t *word_p ));
static u32_t le32 _ARGS(( u32_t *word_p ));
static u16_t be16 _ARGS(( u16_t *word_p ));
static u32_t be32 _ARGS(( u32_t *word_p ));
static u16_t le16(word_p)
u16_t *word_p;
{
return (((u8_t *)word_p)[0] << 0) | (((u8_t *)word_p)[1] << 8);
}
static u16_t be16(word_p)
u16_t *word_p;
{
return (((u8_t *)word_p)[1] << 0) | (((u8_t *)word_p)[0] << 8);
}
static u32_t le32(dword_p)
u32_t *dword_p;
{
return le16(&((u16_t *)dword_p)[0]) |
((u32_t)le16(&((u16_t *)dword_p)[1]) << 16);
}
static u32_t be32(dword_p)
u32_t *dword_p;
{
return be16(&((u16_t *)dword_p)[1]) |
((u32_t)be16(&((u16_t *)dword_p)[0]) << 16);
}
#ifndef USE_OLD_NLIST
struct old_nlist
{
char n_name[8];
long n_value;
unsigned char n_sclass;
unsigned char n_numaux;
unsigned char n_type;
};
/* Low bits of storage class (section). */
#define O_N_SECT 07 /* section mask */
#define O_N_UNDF 00 /* undefined */
#define O_N_ABS 01 /* absolute */
#define O_N_TEXT 02 /* text */
#define O_N_DATA 03 /* data */
#define O_N_BSS 04 /* bss */
#define O_N_COMM 05 /* (common) */
/* High bits of storage class. */
#define O_N_CLASS 0370 /* storage class mask */
#define O_C_NULL
#define O_C_EXT 0020 /* external symbol */
#define O_C_STAT 0030 /* static */
#endif
int read_nlist(filename, nlist_table)
const char *filename;
struct nlist **nlist_table;
{
int r, n_entries, save_err;
u32_t (*cnv32) _ARGS(( u32_t *addr ));
u16_t (*cnv16) _ARGS(( u16_t *addr ));
struct nlist *nlist_p, *nlist_ptr;
int exec_fd;
struct exec exec_header;
#ifndef USE_OLD_NLIST
struct old_nlist *old_nlist, *old_nlist_p;
void *old_nlist_end;
#endif
char *str_tab, *str_base, *str_null;
u32_t string_siz;
exec_fd= open(filename, O_RDONLY);
if (exec_fd == -1) /* No executable present */
{
return -1;
}
r= read(exec_fd, (char *)&exec_header, A_MINHDR);
if (r != A_MINHDR)
{
if (r != -1)
errno= ENOEXEC;
return -1;
}
if (BADMAG(exec_header))
{
errno= ENOEXEC;
return -1;
}
switch(exec_header.a_cpu & 3)
{
case 0: /* little endian */
cnv32= le32;
cnv16= le16;
break;
case 3: /* big endian */
cnv32= be32;
cnv16= be16;
break;
default:
errno= ENOEXEC;
return -1;
}
exec_header.a_version= cnv16((u16_t *)&exec_header.a_version);
exec_header.a_text= cnv32((u32_t *)&exec_header.a_text);
exec_header.a_data= cnv32((u32_t *)&exec_header.a_data);
exec_header.a_bss= cnv32((u32_t *)&exec_header.a_bss);
exec_header.a_entry= cnv32((u32_t *)&exec_header.a_entry);
exec_header.a_total= cnv32((u32_t *)&exec_header.a_total);
exec_header.a_syms= cnv32((u32_t *)&exec_header.a_syms);
exec_header.a_trsize= cnv32((u32_t *)&exec_header.a_trsize);
exec_header.a_drsize= cnv32((u32_t *)&exec_header.a_drsize);
exec_header.a_tbase= cnv32((u32_t *)&exec_header.a_tbase);
exec_header.a_dbase= cnv32((u32_t *)&exec_header.a_dbase);
if (!exec_header.a_syms)
return 0;
if (exec_header.a_flags & A_NSYM)
{
#if USE_OLD_NLIST
errno= EINVAL;
return -1;
#else
r= lseek(exec_fd, A_SYMPOS(exec_header)+exec_header.a_syms,
SEEK_SET);
if (r == -1)
{
return -1;
}
r= read(exec_fd, (char *)&string_siz, 4);
if (r != 4)
return -1;
string_siz= cnv32(&string_siz)-4;
nlist_p= malloc(exec_header.a_syms + string_siz+1);
if (!nlist_p)
{
errno= ENOMEM;
return -1;
}
r= lseek(exec_fd, A_SYMPOS(exec_header)+exec_header.a_syms+4,
SEEK_SET);
if (r == -1)
{
save_err= errno;
free(nlist_p);
errno= save_err;
return -1;
}
r= read(exec_fd, ((char *)nlist_p)+exec_header.a_syms,
string_siz);
if (r != string_siz)
{
save_err= errno;
free(nlist_p);
errno= save_err;
return -1;
}
r= lseek(exec_fd, A_SYMPOS(exec_header), SEEK_SET);
if (r == -1)
{
save_err= errno;
free(nlist_p);
errno= save_err;
return -1;
}
r= read(exec_fd, ((char *)nlist_p), exec_header.a_syms);
if (r != exec_header.a_syms)
{
save_err= errno;
free(nlist_p);
errno= save_err;
return -1;
}
str_base= ((char *)nlist_p) + exec_header.a_syms -4;
str_null= (char *)nlist_p + exec_header.a_syms + string_siz;
*str_null= '\0';
for (nlist_ptr= nlist_p; (char *)nlist_ptr+1 <= str_base+4;
nlist_ptr++)
{
nlist_ptr->n_desc= le16((u16_t *)&nlist_ptr->n_desc);
nlist_ptr->n_value= le32(&nlist_ptr->n_value);
if (nlist_ptr->n_un.n_strx)
nlist_ptr->n_un.n_name= str_base+
cnv32((u32_t *)&nlist_ptr->n_un.n_strx);
else
nlist_ptr->n_un.n_name= str_null;
}
*nlist_table= nlist_p;
return nlist_ptr-nlist_p;
#endif
}
else
{
r= lseek(exec_fd, A_SYMPOS(exec_header), SEEK_SET);
if (r == -1)
{
return -1;
}
#if USE_OLD_NLIST
n_entries= exec_header.a_syms/sizeof(struct nlist);
nlist_p= malloc(exec_header.a_syms);
if (!nlist_p)
{
free(nlist_p);
errno= ENOMEM;
return -1;
}
r= read(exec_fd, (char *)nlist_p, exec_header.a_syms);
if (r != exec_header.a_syms)
{
save_err= errno;
free(nlist_p);
errno= save_err;
return -1;
}
*nlist_table= nlist_p;
return n_entries;
#else
n_entries= exec_header.a_syms/sizeof(struct old_nlist)+1;
nlist_p= NULL;
old_nlist= NULL;
nlist_p= malloc(n_entries * (sizeof(struct nlist)+
sizeof(old_nlist->n_name)+1));
old_nlist= malloc(exec_header.a_syms);
if (!old_nlist || !nlist_p)
{
if (nlist_p)
free(nlist_p);
if (old_nlist)
free(old_nlist);
errno= ENOMEM;
return -1;
}
r= read(exec_fd, (char *)old_nlist, exec_header.a_syms);
if (r != exec_header.a_syms)
{
save_err= errno;
free(nlist_p);
free(old_nlist);
errno= save_err;
return -1;
}
old_nlist_end= (char *)old_nlist+exec_header.a_syms;
str_tab= (char *)&nlist_p[n_entries];
n_entries= 0;
for (old_nlist_p= old_nlist;
(void *)(old_nlist_p+1)<=old_nlist_end; old_nlist_p++)
{
switch(old_nlist_p->n_sclass & O_N_SECT)
{
case O_N_UNDF:
nlist_p[n_entries].n_type= N_UNDF;
break;
case O_N_ABS:
nlist_p[n_entries].n_type= N_ABS;
break;
case O_N_TEXT:
nlist_p[n_entries].n_type= N_TEXT;
break;
case O_N_DATA:
nlist_p[n_entries].n_type= N_DATA;
break;
case O_N_BSS:
nlist_p[n_entries].n_type= N_BSS;
break;
case O_N_COMM:
nlist_p[n_entries].n_type= N_COMM;
break;
default:
continue;
}
switch(old_nlist_p->n_sclass & O_N_CLASS)
{
case O_C_EXT:
nlist_p[n_entries].n_type |= N_EXT;
case O_C_STAT:
break;
default:
continue;
}
nlist_p[n_entries].n_value=
cnv32((u32_t *)&old_nlist_p->n_value);
nlist_p[n_entries].n_un.n_name= str_tab;
memcpy(str_tab, old_nlist_p->n_name,
sizeof(old_nlist_p->n_name));
str_tab += sizeof(old_nlist_p->n_name);
*str_tab++= '\0';
n_entries++;
}
free(old_nlist);
nlist_p= realloc(nlist_p, str_tab-(char *)nlist_p);
*nlist_table= nlist_p;
return n_entries;
#endif
}
}
/*
* $PchId: read_nlist.c,v 1.5 1996/04/11 07:47:38 philip Exp $
*/