static int
_elf_update_pointers(Elf *elf, char *outbuf, size_t len) {
Elf_Scn *scn;
Scn_Data *sd;
char *data, *rawdata;
elf_assert(elf);
elf_assert(elf->e_data);
elf_assert(!elf->e_parent);
elf_assert(!elf->e_unmap_data);
elf_assert(elf->e_kind == ELF_K_ELF);
elf_assert(len >= EI_NIDENT);
/* resize memory images */
if (len <= elf->e_dsize) {
/* don't shorten the memory image */
data = elf->e_data;
}
else if ((data = (char*)realloc(elf->e_data, len))) {
elf->e_dsize = len;
}
else {
seterr(ERROR_IO_2BIG);
return -1;
}
if (elf->e_rawdata == elf->e_data) {
/* update frozen raw image */
memcpy(data, outbuf, len);
elf->e_data = elf->e_rawdata = data;
/* cooked data is stored outside the raw image */
return 0;
}
if (elf->e_rawdata) {
/* update raw image */
if (!(rawdata = (char*)realloc(elf->e_rawdata, len))) {
seterr(ERROR_IO_2BIG);
return -1;
}
memcpy(rawdata, outbuf, len);
elf->e_rawdata = rawdata;
}
if (data == elf->e_data) {
/* nothing more to do */
return 0;
}
/* adjust internal pointers */
for (scn = elf->e_scn_1; scn; scn = scn->s_link) {
elf_assert(scn->s_magic == SCN_MAGIC);
elf_assert(scn->s_elf == elf);
if ((sd = scn->s_data_1)) {
elf_assert(sd->sd_magic == DATA_MAGIC);
elf_assert(sd->sd_scn == scn);
if (sd->sd_memdata && !sd->sd_free_data) {
elf_assert(ptrinside(sd->sd_memdata, elf->e_data, elf->e_dsize));
if (sd->sd_data.d_buf == sd->sd_memdata) {
newptr(sd->sd_memdata, elf->e_data, data);
sd->sd_data.d_buf = sd->sd_memdata;
}
else {
newptr(sd->sd_memdata, elf->e_data, data);
}
}
}
if ((sd = scn->s_rawdata)) {
elf_assert(sd->sd_magic == DATA_MAGIC);
elf_assert(sd->sd_scn == scn);
if (sd->sd_memdata && sd->sd_free_data) {
size_t off, len;
if (elf->e_class == ELFCLASS32) {
off = scn->s_shdr32.sh_offset;
len = scn->s_shdr32.sh_size;
}
#if __LIBELF64
else if (elf->e_class == ELFCLASS64) {
off = scn->s_shdr64.sh_offset;
len = scn->s_shdr64.sh_size;
}
#endif /* __LIBELF64 */
else {
seterr(ERROR_UNIMPLEMENTED);
return -1;
}
if (!(rawdata = (char*)realloc(sd->sd_memdata, len))) {
seterr(ERROR_IO_2BIG);
return -1;
}
memcpy(rawdata, outbuf + off, len);
if (sd->sd_data.d_buf == sd->sd_memdata) {
sd->sd_data.d_buf = rawdata;
}
sd->sd_memdata = rawdata;
}
}
}
elf->e_data = data;
return 0;
}
static off_t
_elf32_write(Elf *elf, char *outbuf, size_t len) {
Elf32_Ehdr *ehdr;
Elf32_Shdr *shdr;
Elf_Scn *scn;
Scn_Data *sd;
Elf_Data src;
Elf_Data dst;
unsigned encode;
elf_assert(len);
elf_assert(elf->e_ehdr);
ehdr = (Elf32_Ehdr*)elf->e_ehdr;
encode = ehdr->e_ident[EI_DATA];
src.d_buf = ehdr;
src.d_type = ELF_T_EHDR;
src.d_size = _msize(ELFCLASS32, _elf_version, ELF_T_EHDR);
src.d_version = _elf_version;
dst.d_buf = outbuf;
dst.d_size = ehdr->e_ehsize;
dst.d_version = ehdr->e_version;
if (!elf32_xlatetof(&dst, &src, encode)) {
return -1;
}
if (elf->e_phnum) {
src.d_buf = elf->e_phdr;
src.d_type = ELF_T_PHDR;
src.d_size = elf->e_phnum * _msize(ELFCLASS32, _elf_version, ELF_T_PHDR);
src.d_version = _elf_version;
dst.d_buf = outbuf + ehdr->e_phoff;
dst.d_size = elf->e_phnum * ehdr->e_phentsize;
dst.d_version = ehdr->e_version;
if (!elf32_xlatetof(&dst, &src, encode)) {
return -1;
}
}
for (scn = elf->e_scn_1; scn; scn = scn->s_link) {
elf_assert(scn->s_magic == SCN_MAGIC);
elf_assert(scn->s_elf == elf);
src.d_buf = &scn->s_uhdr;
src.d_type = ELF_T_SHDR;
src.d_size = _msize(ELFCLASS32, EV_CURRENT, ELF_T_SHDR);
src.d_version = EV_CURRENT;
dst.d_buf = outbuf + ehdr->e_shoff + scn->s_index * ehdr->e_shentsize;
dst.d_size = ehdr->e_shentsize;
dst.d_version = ehdr->e_version;
if (!elf32_xlatetof(&dst, &src, encode)) {
return -1;
}
if (scn->s_index == SHN_UNDEF) {
continue;
}
shdr = &scn->s_shdr32;
if (shdr->sh_type == SHT_NULL || shdr->sh_type == SHT_NOBITS) {
continue;
}
/* XXX: this is probably no longer necessary */
if (scn->s_data_1 && !elf_getdata(scn, NULL)) {
return -1;
}
for (sd = scn->s_data_1; sd; sd = sd->sd_link) {
elf_assert(sd->sd_magic == DATA_MAGIC);
elf_assert(sd->sd_scn == scn);
src = sd->sd_data;
if (!src.d_size) {
continue;
}
if (!src.d_buf) {
seterr(ERROR_NULLBUF);
return -1;
}
dst.d_buf = outbuf + shdr->sh_offset + src.d_off;
dst.d_size = src.d_size;
dst.d_version = ehdr->e_version;
if (valid_type(src.d_type)) {
size_t tmp;
tmp = _elf32_xltsize(&src, dst.d_version, ELFDATA2LSB, 1);
if (tmp == (size_t)-1) {
return -1;
}
dst.d_size = tmp;
}
else {
src.d_type = ELF_T_BYTE;
}
if (!elf32_xlatetof(&dst, &src, encode)) {
return -1;
}
}
}
/* cleanup */
if (elf->e_readable && _elf_update_pointers(elf, outbuf, len)) {
return -1;
}
/* NOTE: ehdr is no longer valid! */
ehdr = (Elf32_Ehdr*)elf->e_ehdr; elf_assert(ehdr);
elf->e_encoding = ehdr->e_ident[EI_DATA];
elf->e_version = ehdr->e_ident[EI_VERSION];
elf->e_elf_flags &= ~ELF_F_DIRTY;
elf->e_ehdr_flags &= ~ELF_F_DIRTY;
elf->e_phdr_flags &= ~ELF_F_DIRTY;
for (scn = elf->e_scn_1; scn; scn = scn->s_link) {
scn->s_scn_flags &= ~ELF_F_DIRTY;
scn->s_shdr_flags &= ~ELF_F_DIRTY;
for (sd = scn->s_data_1; sd; sd = sd->sd_link) {
sd->sd_data_flags &= ~ELF_F_DIRTY;
}
if (elf->e_readable) {
shdr = &scn->s_shdr32;
scn->s_type = shdr->sh_type;
scn->s_size = shdr->sh_size;
scn->s_offset = shdr->sh_offset;
}
}
elf->e_size = len;
return len;
}
static off_t
scn_data_layout(Elf_Scn *scn, unsigned v, unsigned type, size_t *algn, unsigned *flag) {
Elf *elf = scn->s_elf;
Elf_Data *data;
int layout = (elf->e_elf_flags & ELF_F_LAYOUT) == 0;
size_t scn_align = 1;
size_t len = 0;
Scn_Data *sd;
size_t fsize;
if (!(sd = scn->s_data_1)) {
/* no data in section */
*algn = scn_align;
return (off_t)len;
}
/* load data from file, if any */
if (!(data = elf_getdata(scn, NULL))) {
return (off_t)-1;
}
elf_assert(data == &sd->sd_data);
for (; sd; sd = sd->sd_link) {
elf_assert(sd->sd_magic == DATA_MAGIC);
elf_assert(sd->sd_scn == scn);
if (!valid_version(sd->sd_data.d_version)) {
return (off_t)-1;
}
fsize = sd->sd_data.d_size;
if (fsize && type != SHT_NOBITS && valid_type(sd->sd_data.d_type)) {
if (elf->e_class == ELFCLASS32) {
fsize = _elf32_xltsize(&sd->sd_data, v, ELFDATA2LSB, 1);
}
#if __LIBELF64
else if (elf->e_class == ELFCLASS64) {
fsize = _elf64_xltsize(&sd->sd_data, v, ELFDATA2LSB, 1);
}
#endif /* __LIBELF64 */
else {
elf_assert(valid_class(elf->e_class));
seterr(ERROR_UNIMPLEMENTED);
return (off_t)-1;
}
if (fsize == (size_t)-1) {
return (off_t)-1;
}
}
if (layout) {
align(len, sd->sd_data.d_align);
scn_align = max(scn_align, sd->sd_data.d_align);
rewrite(sd->sd_data.d_off, (off_t)len, sd->sd_data_flags);
len += fsize;
}
else {
len = max(len, sd->sd_data.d_off + fsize);
}
*flag |= sd->sd_data_flags;
}
*algn = scn_align;
return (off_t)len;
}
static off_t
_elf64_layout(Elf *elf, unsigned *flag) {
int layout = (elf->e_elf_flags & ELF_F_LAYOUT) == 0;
Elf64_Ehdr *ehdr = (Elf64_Ehdr*)elf->e_ehdr;
size_t off = 0;
unsigned version;
unsigned encoding;
size_t align_addr;
size_t entsize;
unsigned phnum;
unsigned shnum;
Elf_Scn *scn;
*flag = elf->e_elf_flags | elf->e_phdr_flags;
if ((version = ehdr->e_version) == EV_NONE) {
version = EV_CURRENT;
}
if (!valid_version(version)) {
seterr(ERROR_UNKNOWN_VERSION);
return -1;
}
if ((encoding = ehdr->e_ident[EI_DATA]) == ELFDATANONE) {
encoding = native_encoding;
}
if (!valid_encoding(encoding)) {
seterr(ERROR_UNKNOWN_ENCODING);
return -1;
}
entsize = _fsize(ELFCLASS64, version, ELF_T_EHDR);
elf_assert(entsize);
rewrite(ehdr->e_ehsize, entsize, elf->e_ehdr_flags);
off = entsize;
align_addr = _fsize(ELFCLASS64, version, ELF_T_ADDR);
elf_assert(align_addr);
if ((phnum = elf->e_phnum)) {
entsize = _fsize(ELFCLASS64, version, ELF_T_PHDR);
elf_assert(entsize);
if (layout) {
align(off, align_addr);
rewrite(ehdr->e_phoff, off, elf->e_ehdr_flags);
off += phnum * entsize;
}
else {
off = max(off, ehdr->e_phoff + phnum * entsize);
}
}
else {
entsize = 0;
if (layout) {
rewrite(ehdr->e_phoff, 0, elf->e_ehdr_flags);
}
}
if (phnum >= PN_XNUM) {
Elf_Scn *scn = elf->e_scn_1;
Elf32_Shdr *shdr = &scn->s_shdr32;
/* modify first section header, too! */
elf_assert(scn);
elf_assert(scn->s_index == 0);
rewrite(shdr->sh_info, phnum, scn->s_shdr_flags);
*flag |= scn->s_shdr_flags;
phnum = PN_XNUM;
}
rewrite(ehdr->e_phnum, phnum, elf->e_ehdr_flags);
rewrite(ehdr->e_phentsize, entsize, elf->e_ehdr_flags);
for (scn = elf->e_scn_1, shnum = 0; scn; scn = scn->s_link, ++shnum) {
Elf64_Shdr *shdr = &scn->s_shdr64;
size_t scn_align = 1;
off_t len;
elf_assert(scn->s_index == shnum);
*flag |= scn->s_scn_flags;
if (scn->s_index == SHN_UNDEF) {
rewrite(shdr->sh_entsize, 0, scn->s_shdr_flags);
if (layout) {
rewrite(shdr->sh_offset, 0, scn->s_shdr_flags);
rewrite(shdr->sh_size, 0, scn->s_shdr_flags);
rewrite(shdr->sh_addralign, 0, scn->s_shdr_flags);
}
*flag |= scn->s_shdr_flags;
continue;
}
if (shdr->sh_type == SHT_NULL) {
*flag |= scn->s_shdr_flags;
continue;
}
len = scn_data_layout(scn, version, shdr->sh_type, &scn_align, flag);
if (len == -1) {
return -1;
}
/*
* Never override the program's choice.
*/
if (shdr->sh_entsize == 0) {
entsize = scn_entsize(elf, version, shdr->sh_type);
if (entsize > 1) {
rewrite(shdr->sh_entsize, entsize, scn->s_shdr_flags);
}
}
if (layout) {
align(off, scn_align);
rewrite(shdr->sh_offset, off, scn->s_shdr_flags);
rewrite(shdr->sh_size, (size_t)len, scn->s_shdr_flags);
rewrite(shdr->sh_addralign, scn_align, scn->s_shdr_flags);
if (shdr->sh_type != SHT_NOBITS) {
off += (size_t)len;
}
}
else if ((size_t)len > shdr->sh_size) {
seterr(ERROR_SCN2SMALL);
return -1;
}
else {
Elf_Scn *scn2;
size_t end1, end2;
end1 = shdr->sh_offset;
if (shdr->sh_type != SHT_NOBITS) {
end1 += shdr->sh_size;
}
if (shdr->sh_offset < off) {
/*
* check for overlapping sections
*/
for (scn2 = elf->e_scn_1; scn2; scn2 = scn2->s_link) {
if (scn2 == scn) {
break;
}
end2 = scn2->s_shdr64.sh_offset;
if (scn2->s_shdr64.sh_type != SHT_NOBITS) {
end2 += scn2->s_shdr64.sh_size;
}
if (end1 > scn2->s_shdr64.sh_offset
&& end2 > shdr->sh_offset) {
seterr(ERROR_SCN_OVERLAP);
return -1;
}
}
}
if (off < end1) {
off = end1;
}
}
*flag |= scn->s_shdr_flags;
}
if (shnum) {
entsize = _fsize(ELFCLASS64, version, ELF_T_SHDR);
elf_assert(entsize);
if (layout) {
align(off, align_addr);
rewrite(ehdr->e_shoff, off, elf->e_ehdr_flags);
off += shnum * entsize;
}
else {
off = max(off, ehdr->e_shoff + shnum * entsize);
}
}
else {
entsize = 0;
if (layout) {
rewrite(ehdr->e_shoff, 0, elf->e_ehdr_flags);
}
}
if (shnum >= SHN_LORESERVE) {
Elf_Scn *scn = elf->e_scn_1;
Elf64_Shdr *shdr = &scn->s_shdr64;
elf_assert(scn->s_index == 0);
rewrite(shdr->sh_size, shnum, scn->s_shdr_flags);
*flag |= scn->s_shdr_flags;
shnum = 0;
}
rewrite(ehdr->e_shnum, shnum, elf->e_ehdr_flags);
rewrite(ehdr->e_shentsize, entsize, elf->e_ehdr_flags);
rewrite(ehdr->e_ident[EI_MAG0], ELFMAG0, elf->e_ehdr_flags);
rewrite(ehdr->e_ident[EI_MAG1], ELFMAG1, elf->e_ehdr_flags);
rewrite(ehdr->e_ident[EI_MAG2], ELFMAG2, elf->e_ehdr_flags);
rewrite(ehdr->e_ident[EI_MAG3], ELFMAG3, elf->e_ehdr_flags);
rewrite(ehdr->e_ident[EI_CLASS], ELFCLASS64, elf->e_ehdr_flags);
rewrite(ehdr->e_ident[EI_DATA], encoding, elf->e_ehdr_flags);
rewrite(ehdr->e_ident[EI_VERSION], version, elf->e_ehdr_flags);
rewrite(ehdr->e_version, version, elf->e_ehdr_flags);
*flag |= elf->e_ehdr_flags;
return off;
}
Elf_Data*
elf_getdata(Elf_Scn *scn, Elf_Data *data) {
Scn_Data *sd;
Elf *elf;
if (!scn) {
return NULL;
}
elf_assert(scn->s_magic == SCN_MAGIC);
if (scn->s_index == SHN_UNDEF) {
seterr(ERROR_NULLSCN);
}
else if (data) {
for (sd = scn->s_data_1; sd; sd = sd->sd_link) {
elf_assert(sd->sd_magic == DATA_MAGIC);
elf_assert(sd->sd_scn == scn);
if (data == &sd->sd_data) {
/*
* sd_link allocated by elf_newdata().
*/
return &sd->sd_link->sd_data;
}
}
seterr(ERROR_SCNDATAMISMATCH);
}
else if ((sd = scn->s_data_1)) {
elf_assert(sd->sd_magic == DATA_MAGIC);
elf_assert(sd->sd_scn == scn);
elf = scn->s_elf;
elf_assert(elf);
elf_assert(elf->e_magic == ELF_MAGIC);
if (sd->sd_freeme) {
/* allocated by elf_newdata() */
return &sd->sd_data;
}
else if (scn->s_type == SHT_NULL) {
seterr(ERROR_NULLSCN);
}
else if (sd->sd_memdata) {
/* already cooked */
return &sd->sd_data;
}
else if (scn->s_offset < 0 || scn->s_offset > elf->e_size) {
seterr(ERROR_OUTSIDE);
}
else if (scn->s_type == SHT_NOBITS || !scn->s_size) {
/* no data to read */
return &sd->sd_data;
}
else if (scn->s_offset + scn->s_size > elf->e_size) {
seterr(ERROR_TRUNC_SCN);
}
else if (valid_class(elf->e_class)) {
return _elf_cook_scn(elf, scn, sd);
}
else {
seterr(ERROR_UNKNOWN_CLASS);
}
}
return NULL;
}
static Elf_Data*
_elf_cook_scn(Elf *elf, Elf_Scn *scn, Scn_Data *sd) {
Elf_Data dst;
Elf_Data src;
int flag = 0;
size_t dlen;
elf_assert(elf->e_data);
/*
* Prepare source
*/
src = sd->sd_data;
src.d_version = elf->e_version;
if (elf->e_rawdata) {
src.d_buf = elf->e_rawdata + scn->s_offset;
}
else {
src.d_buf = elf->e_data + scn->s_offset;
}
/*
* Prepare destination (needs prepared source!)
*/
dst = sd->sd_data;
if (elf->e_class == ELFCLASS32) {
dlen = _elf32_xltsize(&src, dst.d_version, elf->e_encoding, 0);
}
#if __LIBELF64
else if (elf->e_class == ELFCLASS64) {
dlen = _elf64_xltsize(&src, dst.d_version, elf->e_encoding, 0);
}
#endif /* __LIBELF64 */
else {
elf_assert(valid_class(elf->e_class));
seterr(ERROR_UNIMPLEMENTED);
return NULL;
}
if (dlen == (size_t)-1) {
return NULL;
}
dst.d_size = dlen;
if (elf->e_rawdata != elf->e_data && dst.d_size <= src.d_size) {
dst.d_buf = elf->e_data + scn->s_offset;
}
else if (!(dst.d_buf = malloc(dst.d_size))) {
seterr(ERROR_MEM_SCNDATA);
return NULL;
}
else {
flag = 1;
}
/*
* Translate data
*/
if (_elf_xlatetom(elf, &dst, &src)) {
sd->sd_memdata = (char*)dst.d_buf;
sd->sd_data = dst;
if (!(sd->sd_free_data = flag)) {
elf->e_cooked = 1;
}
return &sd->sd_data;
}
if (flag) {
free(dst.d_buf);
}
return NULL;
}
Elf_Arsym*
elf_getarsym(Elf *elf, size_t *ptr) {
Elf_Arsym *syms;
size_t count;
size_t tmp;
size_t i;
char *s;
char *e;
if (!ptr) {
ptr = &tmp;
}
*ptr = 0;
if (!elf) {
return NULL;
}
elf_assert(elf->e_magic == ELF_MAGIC);
if (elf->e_kind != ELF_K_AR) {
seterr(ERROR_NOTARCHIVE);
return NULL;
}
if (elf->e_symtab && !elf->e_free_syms) {
if (elf->e_symlen < 4) {
seterr(ERROR_SIZE_ARSYMTAB);
return NULL;
}
count = __load_u32M(elf->e_symtab);
if (elf->e_symlen < 4 * (count + 1)) {
seterr(ERROR_SIZE_ARSYMTAB);
return NULL;
}
if (!(syms = (Elf_Arsym*)malloc((count + 1) * sizeof(*syms)))) {
seterr(ERROR_MEM_ARSYMTAB);
return NULL;
}
s = elf->e_symtab + 4 * (count + 1);
e = elf->e_symtab + elf->e_symlen;
for (i = 0; i < count; i++, s++) {
syms[i].as_name = s;
while (s < e && *s) {
s++;
}
if (s >= e) {
seterr(ERROR_SIZE_ARSYMTAB);
free(syms);
return NULL;
}
elf_assert(!*s);
syms[i].as_hash = elf_hash(syms[i].as_name);
syms[i].as_off = __load_u32M(elf->e_symtab + 4 * (i + 1));
}
syms[count].as_name = NULL;
syms[count].as_hash = ~0UL;
syms[count].as_off = 0;
elf->e_symtab = (char*)syms;
elf->e_symlen = count + 1;
elf->e_free_syms = 1;
}
*ptr = elf->e_symlen;
return (Elf_Arsym*)elf->e_symtab;
}
