size_t
gelf_fsize(Elf *e, Elf_Type t, size_t c, unsigned int v)
{
if (e == NULL) {
LIBELF_SET_ERROR(ARGUMENT, 0);
return (0);
}
if (e->e_class == ELFCLASS32 || e->e_class == ELFCLASS64)
return (_libelf_fsize(t, e->e_class, v, c));
LIBELF_SET_ERROR(ARGUMENT, 0);
return (0);
}
/*
* Retrieve counts for sections, phdrs and the section string table index
* from section header #0 of the ELF object.
*/
static int
_libelf_load_extended(Elf *e, int ec, uint64_t shoff, uint16_t phnum,
uint16_t strndx)
{
Elf_Scn *scn;
size_t fsz;
int (*xlator)(unsigned char *_d, size_t _dsz, unsigned char *_s,
size_t _c, int _swap);
uint32_t shtype;
assert(STAILQ_EMPTY(&e->e_u.e_elf.e_scn));
fsz = _libelf_fsize(ELF_T_SHDR, ec, e->e_version, 1);
assert(fsz > 0);
if (e->e_rawsize < shoff + fsz) { /* raw file too small */
LIBELF_SET_ERROR(HEADER, 0);
return (0);
}
if ((scn = _libelf_allocate_scn(e, (size_t) 0)) == NULL)
return (0);
xlator = _libelf_get_translator(ELF_T_SHDR, ELF_TOMEMORY, ec);
(*xlator)((unsigned char *) &scn->s_shdr, sizeof(scn->s_shdr),
(unsigned char *) e->e_rawfile + shoff, (size_t) 1,
e->e_byteorder != LIBELF_PRIVATE(byteorder));
#define GET_SHDR_MEMBER(M) ((ec == ELFCLASS32) ? scn->s_shdr.s_shdr32.M : \
scn->s_shdr.s_shdr64.M)
if ((shtype = GET_SHDR_MEMBER(sh_type)) != SHT_NULL) {
LIBELF_SET_ERROR(SECTION, 0);
return (0);
}
e->e_u.e_elf.e_nscn = (size_t) GET_SHDR_MEMBER(sh_size);
e->e_u.e_elf.e_nphdr = (phnum != PN_XNUM) ? phnum :
GET_SHDR_MEMBER(sh_info);
e->e_u.e_elf.e_strndx = (strndx != SHN_XINDEX) ? strndx :
GET_SHDR_MEMBER(sh_link);
#undef GET_SHDR_MEMBER
return (1);
}
void *
_libelf_ehdr(Elf *e, int ec, int allocate)
{
void *ehdr;
size_t fsz, msz;
uint16_t phnum, shnum, strndx;
uint64_t shoff;
int (*xlator)(unsigned char *_d, size_t _dsz, unsigned char *_s,
size_t _c, int _swap);
assert(ec == ELFCLASS32 || ec == ELFCLASS64);
if (e == NULL || e->e_kind != ELF_K_ELF) {
LIBELF_SET_ERROR(ARGUMENT, 0);
return (NULL);
}
if (e->e_class != ELFCLASSNONE && e->e_class != ec) {
LIBELF_SET_ERROR(CLASS, 0);
return (NULL);
}
if (e->e_version != EV_CURRENT) {
LIBELF_SET_ERROR(VERSION, 0);
return (NULL);
}
if (e->e_class == ELFCLASSNONE)
e->e_class = ec;
if (ec == ELFCLASS32)
ehdr = (void *) e->e_u.e_elf.e_ehdr.e_ehdr32;
else
ehdr = (void *) e->e_u.e_elf.e_ehdr.e_ehdr64;
if (ehdr != NULL) /* already have a translated ehdr */
return (ehdr);
fsz = _libelf_fsize(ELF_T_EHDR, ec, e->e_version, (size_t) 1);
assert(fsz > 0);
if (e->e_cmd != ELF_C_WRITE && e->e_rawsize < fsz) {
LIBELF_SET_ERROR(HEADER, 0);
return (NULL);
}
msz = _libelf_msize(ELF_T_EHDR, ec, EV_CURRENT);
assert(msz > 0);
if ((ehdr = calloc((size_t) 1, msz)) == NULL) {
LIBELF_SET_ERROR(RESOURCE, 0);
return (NULL);
}
if (ec == ELFCLASS32) {
e->e_u.e_elf.e_ehdr.e_ehdr32 = ehdr;
EHDR_INIT(ehdr,32);
} else {
e->e_u.e_elf.e_ehdr.e_ehdr64 = ehdr;
EHDR_INIT(ehdr,64);
}
if (allocate)
e->e_flags |= ELF_F_DIRTY;
if (e->e_cmd == ELF_C_WRITE)
return (ehdr);
xlator = _libelf_get_translator(ELF_T_EHDR, ELF_TOMEMORY, ec);
(*xlator)((unsigned char*) ehdr, msz, e->e_rawfile, (size_t) 1,
e->e_byteorder != LIBELF_PRIVATE(byteorder));
if (ec == ELFCLASS32) {
phnum = ((Elf32_Ehdr *) ehdr)->e_phnum;
shnum = ((Elf32_Ehdr *) ehdr)->e_shnum;
shoff = ((Elf32_Ehdr *) ehdr)->e_shoff;
strndx = ((Elf32_Ehdr *) ehdr)->e_shstrndx;
} else {
phnum = ((Elf64_Ehdr *) ehdr)->e_phnum;
shnum = ((Elf64_Ehdr *) ehdr)->e_shnum;
shoff = ((Elf64_Ehdr *) ehdr)->e_shoff;
strndx = ((Elf64_Ehdr *) ehdr)->e_shstrndx;
}
if (shnum >= SHN_LORESERVE ||
(shoff == 0LL && (shnum != 0 || phnum == PN_XNUM ||
strndx == SHN_XINDEX))) {
LIBELF_SET_ERROR(HEADER, 0);
return (NULL);
}
/*
* If extended numbering is being used, read the correct
* number of sections and program header entries.
*/
if ((shnum == 0 && shoff != 0) || phnum == PN_XNUM || strndx == SHN_XINDEX) {
if (_libelf_load_extended(e, ec, shoff, phnum, strndx) == 0)
return (NULL);
} else {
/* not using extended numbering */
e->e_u.e_elf.e_nphdr = phnum;
e->e_u.e_elf.e_nscn = shnum;
e->e_u.e_elf.e_strndx = strndx;
}
return (ehdr);
}
size_t
elf64_fsize(Elf_Type t, size_t c, unsigned int v)
{
return (_libelf_fsize(t, ELFCLASS64, v, c));
}
/*
* Load an ELF section table and create a list of Elf_Scn structures.
*/
static int
_libelf_load_scn(Elf *e, void *ehdr)
{
int ec, swapbytes;
size_t fsz, i, shnum;
uint64_t shoff;
char *src;
Elf32_Ehdr *eh32;
Elf64_Ehdr *eh64;
Elf_Scn *scn;
void (*xlator)(char *_d, char *_s, size_t _c, int _swap);
assert(e != NULL);
assert(ehdr != NULL);
assert((e->e_flags & LIBELF_F_SHDRS_LOADED) == 0);
#define CHECK_EHDR(E,EH) do { \
if (fsz != (EH)->e_shentsize || \
shoff + fsz * shnum > e->e_rawsize) { \
LIBELF_SET_ERROR(HEADER, 0); \
return (0); \
} \
} while (0)
ec = e->e_class;
fsz = _libelf_fsize(ELF_T_SHDR, ec, e->e_version, (size_t) 1);
assert(fsz > 0);
shnum = e->e_u.e_elf.e_nscn;
if (ec == ELFCLASS32) {
eh32 = (Elf32_Ehdr *) ehdr;
shoff = (uint64_t) eh32->e_shoff;
CHECK_EHDR(e, eh32);
} else {
eh64 = (Elf64_Ehdr *) ehdr;
shoff = eh64->e_shoff;
CHECK_EHDR(e, eh64);
}
xlator = _libelf_get_translator(ELF_T_SHDR, ELF_TOMEMORY, ec);
swapbytes = e->e_byteorder != LIBELF_PRIVATE(byteorder);
src = e->e_rawfile + shoff;
/*
* If the file is using extended numbering then section #0
* would have already been read in.
*/
i = 0;
if (!STAILQ_EMPTY(&e->e_u.e_elf.e_scn)) {
assert(STAILQ_FIRST(&e->e_u.e_elf.e_scn) ==
STAILQ_LAST(&e->e_u.e_elf.e_scn, _Elf_Scn, s_next));
i = 1;
src += fsz;
}
for (; i < shnum; i++, src += fsz) {
if ((scn = _libelf_allocate_scn(e, i)) == NULL)
return (0);
(*xlator)((char *) &scn->s_shdr, src, (size_t) 1, swapbytes);
if (ec == ELFCLASS32) {
scn->s_offset = scn->s_rawoff =
scn->s_shdr.s_shdr32.sh_offset;
scn->s_size = scn->s_shdr.s_shdr32.sh_size;
} else {
scn->s_offset = scn->s_rawoff =
scn->s_shdr.s_shdr64.sh_offset;
scn->s_size = scn->s_shdr.s_shdr64.sh_size;
}
}
e->e_flags |= LIBELF_F_SHDRS_LOADED;
return (1);
}
