Elf *
elf_memory(char *image, size_t sz)
{
Elf *e;
if (LIBELF_PRIVATE(version) == EV_NONE) {
LIBELF_SET_ERROR(SEQUENCE, 0);
return (NULL);
}
if (image == NULL || sz == 0) {
LIBELF_SET_ERROR(ARGUMENT, 0);
return (NULL);
}
if ((e = _libelf_allocate_elf()) == NULL)
return (NULL);
e->e_cmd = ELF_C_READ;
e->e_rawfile = image;
e->e_rawsize = sz;
#undef LIBELF_IS_ELF
#define LIBELF_IS_ELF(P) ((P)[EI_MAG0] == ELFMAG0 && \
(P)[EI_MAG1] == ELFMAG1 && (P)[EI_MAG2] == ELFMAG2 && \
(P)[EI_MAG3] == ELFMAG3)
if (sz > EI_NIDENT && LIBELF_IS_ELF(image)) {
_libelf_init_elf(e, ELF_K_ELF);
e->e_class = image[EI_CLASS];
e->e_byteorder = image[EI_DATA];
e->e_version = image[EI_VERSION];
if (e->e_version > EV_CURRENT) {
e = _libelf_release_elf(e);
LIBELF_SET_ERROR(VERSION, 0);
return (NULL);
}
if ((e->e_byteorder != ELFDATA2LSB && e->e_byteorder !=
ELFDATA2MSB) || (e->e_class != ELFCLASS32 && e->e_class !=
ELFCLASS64)) {
e = _libelf_release_elf(e);
LIBELF_SET_ERROR(HEADER, 0);
return (NULL);
}
} else if (sz >= SARMAG &&
strncmp(image, ARMAG, (size_t) SARMAG) == 0) {
_libelf_init_elf(e, ELF_K_AR);
e = _libelf_ar_open(e);
} else
_libelf_init_elf(e, ELF_K_NONE);
return (e);
}
Elf *
_libelf_memory(char *image, size_t sz, int reporterror)
{
Elf *e;
int e_class;
enum Elf_Error error;
unsigned int e_byteorder, e_version;
assert(image != NULL);
assert(sz > 0);
if ((e = _libelf_allocate_elf()) == NULL)
return (NULL);
e->e_cmd = ELF_C_READ;
e->e_rawfile = image;
e->e_rawsize = sz;
#undef LIBELF_IS_ELF
#define LIBELF_IS_ELF(P) ((P)[EI_MAG0] == ELFMAG0 && \
(P)[EI_MAG1] == ELFMAG1 && (P)[EI_MAG2] == ELFMAG2 && \
(P)[EI_MAG3] == ELFMAG3)
if (sz > EI_NIDENT && LIBELF_IS_ELF(image)) {
e_byteorder = image[EI_DATA];
e_class = image[EI_CLASS];
e_version = image[EI_VERSION];
error = ELF_E_NONE;
if (e_version > EV_CURRENT)
error = ELF_E_VERSION;
else if ((e_byteorder != ELFDATA2LSB && e_byteorder !=
ELFDATA2MSB) || (e_class != ELFCLASS32 && e_class !=
ELFCLASS64))
error = ELF_E_HEADER;
if (error != ELF_E_NONE) {
if (reporterror) {
LIBELF_PRIVATE(error) = LIBELF_ERROR(error, 0);
(void) _libelf_release_elf(e);
return (NULL);
}
} else {
_libelf_init_elf(e, ELF_K_ELF);
e->e_byteorder = e_byteorder;
e->e_class = e_class;
e->e_version = e_version;
}
} else if (sz >= SARMAG &&
strncmp(image, ARMAG, (size_t) SARMAG) == 0)
return (_libelf_ar_open(e, reporterror));
return (e);
}
Elf *
elf_begin(int fd, Elf_Cmd c, Elf *a)
{
Elf *e;
e = NULL;
if (LIBELF_PRIVATE(version) == EV_NONE) {
LIBELF_SET_ERROR(SEQUENCE, 0);
return (NULL);
}
switch (c) {
case ELF_C_NULL:
return (NULL);
case ELF_C_WRITE:
if (a != NULL) { /* not allowed for ar(1) archives. */
LIBELF_SET_ERROR(ARGUMENT, 0);
return (NULL);
}
/*
* Check writeability of `fd' immediately and fail if
* not writeable.
*/
if (ftruncate(fd, (off_t) 0) < 0) {
LIBELF_SET_ERROR(IO, errno);
return (NULL);
}
if ((e = _libelf_allocate_elf()) != NULL) {
_libelf_init_elf(e, ELF_K_ELF);
e->e_byteorder = LIBELF_PRIVATE(byteorder);
e->e_fd = fd;
e->e_cmd = c;
}
return (e);
case ELF_C_RDWR:
if (a != NULL) { /* not allowed for ar(1) archives. */
LIBELF_SET_ERROR(ARGUMENT, 0);
return (NULL);
}
/*FALLTHROUGH*/
case ELF_C_READ:
/*
* Descriptor `a' could be for a regular ELF file, or
* for an ar(1) archive.
*/
if (a && (a->e_fd != fd || c != a->e_cmd)) {
LIBELF_SET_ERROR(ARGUMENT, 0);
return (NULL);
}
break;
default:
LIBELF_SET_ERROR(ARGUMENT, 0);
return (NULL);
}
if (a == NULL)
e = _libelf_open_object(fd, c);
else if (a->e_kind == ELF_K_AR)
e = _libelf_ar_open_member(fd, c, a);
else
(e = a)->e_activations++;
return (e);
}
Elf *
_libelf_open_object(int fd, Elf_Cmd c, int reporterror)
{
Elf *e;
void *m;
mode_t mode;
size_t fsize;
struct stat sb;
unsigned int flags;
assert(c == ELF_C_READ || c == ELF_C_RDWR || c == ELF_C_WRITE);
if (fstat(fd, &sb) < 0) {
LIBELF_SET_ERROR(IO, errno);
return (NULL);
}
mode = sb.st_mode;
fsize = (size_t) sb.st_size;
/*
* Reject unsupported file types.
*/
if (!S_ISREG(mode) && !S_ISCHR(mode) && !S_ISFIFO(mode) &&
!S_ISSOCK(mode)) {
LIBELF_SET_ERROR(ARGUMENT, 0);
return (NULL);
}
/*
* For ELF_C_WRITE mode, allocate and return a descriptor.
*/
if (c == ELF_C_WRITE) {
if ((e = _libelf_allocate_elf()) != NULL) {
_libelf_init_elf(e, ELF_K_ELF);
e->e_byteorder = LIBELF_PRIVATE(byteorder);
e->e_fd = fd;
e->e_cmd = c;
if (!S_ISREG(mode))
e->e_flags |= LIBELF_F_SPECIAL_FILE;
}
return (e);
}
/*
* ELF_C_READ and ELF_C_RDWR mode.
*/
m = NULL;
flags = 0;
if (S_ISREG(mode)) {
/*
* Reject zero length files.
*/
if (fsize == 0) {
LIBELF_SET_ERROR(ARGUMENT, 0);
return (NULL);
}
#if ELFTC_HAVE_MMAP
/*
* Always map regular files in with 'PROT_READ'
* permissions.
*
* For objects opened in ELF_C_RDWR mode, when
* elf_update(3) is called, we remove this mapping,
* write file data out using write(2), and map the new
* contents back.
*/
m = mmap(NULL, fsize, PROT_READ, MAP_PRIVATE, fd, (off_t) 0);
if (m == MAP_FAILED)
m = NULL;
else
flags = LIBELF_F_RAWFILE_MMAP;
#endif
/*
* Fallback to a read() if the call to mmap() failed,
* or if mmap() is not available.
*/
if (m == NULL) {
if ((m = malloc(fsize)) == NULL) {
LIBELF_SET_ERROR(RESOURCE, 0);
return (NULL);
}
if (read(fd, m, fsize) != (ssize_t) fsize) {
LIBELF_SET_ERROR(IO, errno);
free(m);
return (NULL);
}
flags = LIBELF_F_RAWFILE_MALLOC;
}
} else if ((m = _libelf_read_special_file(fd, &fsize)) != NULL)
flags = LIBELF_F_RAWFILE_MALLOC | LIBELF_F_SPECIAL_FILE;
else
return (NULL);
if ((e = _libelf_memory(m, fsize, reporterror)) == NULL) {
assert((flags & LIBELF_F_RAWFILE_MALLOC) ||
(flags & LIBELF_F_RAWFILE_MMAP));
if (flags & LIBELF_F_RAWFILE_MALLOC)
free(m);
#if ELFTC_HAVE_MMAP
else
(void) munmap(m, fsize);
#endif
return (NULL);
}
/* ar(1) archives aren't supported in RDWR mode. */
if (c == ELF_C_RDWR && e->e_kind == ELF_K_AR) {
(void) elf_end(e);
LIBELF_SET_ERROR(ARGUMENT, 0);
return (NULL);
}
e->e_flags |= flags;
e->e_fd = fd;
e->e_cmd = c;
return (e);
}
