#include "symbol.h"

  #include "util.h"

  #include <errno.h>

  #include <stdio.h>
  #include <fcntl.h>
  #include <string.h>
  #include <byteswap.h>
  #include <sys/stat.h>

  
  static bool check_need_swap(int file_endian)

  {

  	const int data = 1;
  	u8 *check = (u8 *)&data;
  	int host_endian;
  
  	if (check[0] == 1)
  		host_endian = ELFDATA2LSB;
  	else
  		host_endian = ELFDATA2MSB;
  
  	return host_endian != file_endian;

  }

  #define NOTE_ALIGN(sz) (((sz) + 3) & ~3)
  
  #define NT_GNU_BUILD_ID	3
  
  static int read_build_id(void *note_data, size_t note_len, void *bf,
  			 size_t size, bool need_swap)

  {

  	struct {
  		u32 n_namesz;
  		u32 n_descsz;
  		u32 n_type;
  	} *nhdr;
  	void *ptr;
  
  	ptr = note_data;
  	while (ptr < (note_data + note_len)) {
  		const char *name;
  		size_t namesz, descsz;
  
  		nhdr = ptr;
  		if (need_swap) {
  			nhdr->n_namesz = bswap_32(nhdr->n_namesz);
  			nhdr->n_descsz = bswap_32(nhdr->n_descsz);
  			nhdr->n_type = bswap_32(nhdr->n_type);
  		}
  
  		namesz = NOTE_ALIGN(nhdr->n_namesz);
  		descsz = NOTE_ALIGN(nhdr->n_descsz);
  
  		ptr += sizeof(*nhdr);
  		name = ptr;
  		ptr += namesz;
  		if (nhdr->n_type == NT_GNU_BUILD_ID &&
  		    nhdr->n_namesz == sizeof("GNU")) {
  			if (memcmp(name, "GNU", sizeof("GNU")) == 0) {
  				size_t sz = min(size, descsz);
  				memcpy(bf, ptr, sz);
  				memset(bf + sz, 0, size - sz);
  				return 0;
  			}
  		}
  		ptr += descsz;
  	}

  	return -1;
  }

  int filename__read_debuglink(const char *filename __maybe_unused,
  			     char *debuglink __maybe_unused,
  			     size_t size __maybe_unused)

  {
  	return -1;
  }

  /*
   * Just try PT_NOTE header otherwise fails
   */
  int filename__read_build_id(const char *filename, void *bf, size_t size)
  {
  	FILE *fp;
  	int ret = -1;
  	bool need_swap = false;
  	u8 e_ident[EI_NIDENT];
  	size_t buf_size;
  	void *buf;
  	int i;
  
  	fp = fopen(filename, "r");
  	if (fp == NULL)
  		return -1;
  
  	if (fread(e_ident, sizeof(e_ident), 1, fp) != 1)
  		goto out;
  
  	if (memcmp(e_ident, ELFMAG, SELFMAG) ||
  	    e_ident[EI_VERSION] != EV_CURRENT)
  		goto out;
  
  	need_swap = check_need_swap(e_ident[EI_DATA]);
  
  	/* for simplicity */
  	fseek(fp, 0, SEEK_SET);
  
  	if (e_ident[EI_CLASS] == ELFCLASS32) {
  		Elf32_Ehdr ehdr;
  		Elf32_Phdr *phdr;
  
  		if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)
  			goto out;
  
  		if (need_swap) {
  			ehdr.e_phoff = bswap_32(ehdr.e_phoff);
  			ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);
  			ehdr.e_phnum = bswap_16(ehdr.e_phnum);
  		}
  
  		buf_size = ehdr.e_phentsize * ehdr.e_phnum;
  		buf = malloc(buf_size);
  		if (buf == NULL)
  			goto out;
  
  		fseek(fp, ehdr.e_phoff, SEEK_SET);
  		if (fread(buf, buf_size, 1, fp) != 1)
  			goto out_free;
  
  		for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
  			void *tmp;

  			long offset;

  
  			if (need_swap) {
  				phdr->p_type = bswap_32(phdr->p_type);
  				phdr->p_offset = bswap_32(phdr->p_offset);
  				phdr->p_filesz = bswap_32(phdr->p_filesz);
  			}
  
  			if (phdr->p_type != PT_NOTE)
  				continue;
  
  			buf_size = phdr->p_filesz;

  			offset = phdr->p_offset;

  			tmp = realloc(buf, buf_size);
  			if (tmp == NULL)
  				goto out_free;
  
  			buf = tmp;

  			fseek(fp, offset, SEEK_SET);

  			if (fread(buf, buf_size, 1, fp) != 1)
  				goto out_free;
  
  			ret = read_build_id(buf, buf_size, bf, size, need_swap);
  			if (ret == 0)
  				ret = size;
  			break;
  		}
  	} else {
  		Elf64_Ehdr ehdr;
  		Elf64_Phdr *phdr;
  
  		if (fread(&ehdr, sizeof(ehdr), 1, fp) != 1)
  			goto out;
  
  		if (need_swap) {
  			ehdr.e_phoff = bswap_64(ehdr.e_phoff);
  			ehdr.e_phentsize = bswap_16(ehdr.e_phentsize);
  			ehdr.e_phnum = bswap_16(ehdr.e_phnum);
  		}
  
  		buf_size = ehdr.e_phentsize * ehdr.e_phnum;
  		buf = malloc(buf_size);
  		if (buf == NULL)
  			goto out;
  
  		fseek(fp, ehdr.e_phoff, SEEK_SET);
  		if (fread(buf, buf_size, 1, fp) != 1)
  			goto out_free;
  
  		for (i = 0, phdr = buf; i < ehdr.e_phnum; i++, phdr++) {
  			void *tmp;

  			long offset;

  
  			if (need_swap) {
  				phdr->p_type = bswap_32(phdr->p_type);
  				phdr->p_offset = bswap_64(phdr->p_offset);
  				phdr->p_filesz = bswap_64(phdr->p_filesz);
  			}
  
  			if (phdr->p_type != PT_NOTE)
  				continue;
  
  			buf_size = phdr->p_filesz;

  			offset = phdr->p_offset;

  			tmp = realloc(buf, buf_size);
  			if (tmp == NULL)
  				goto out_free;
  
  			buf = tmp;

  			fseek(fp, offset, SEEK_SET);

  			if (fread(buf, buf_size, 1, fp) != 1)
  				goto out_free;
  
  			ret = read_build_id(buf, buf_size, bf, size, need_swap);
  			if (ret == 0)
  				ret = size;
  			break;
  		}
  	}
  out_free:
  	free(buf);
  out:
  	fclose(fp);
  	return ret;
  }
  
  int sysfs__read_build_id(const char *filename, void *build_id, size_t size)
  {
  	int fd;
  	int ret = -1;
  	struct stat stbuf;
  	size_t buf_size;
  	void *buf;
  
  	fd = open(filename, O_RDONLY);
  	if (fd < 0)
  		return -1;
  
  	if (fstat(fd, &stbuf) < 0)
  		goto out;
  
  	buf_size = stbuf.st_size;
  	buf = malloc(buf_size);
  	if (buf == NULL)
  		goto out;
  
  	if (read(fd, buf, buf_size) != (ssize_t) buf_size)
  		goto out_free;
  
  	ret = read_build_id(buf, buf_size, build_id, size, false);
  out_free:
  	free(buf);
  out:
  	close(fd);
  	return ret;
  }

  int symsrc__init(struct symsrc *ss, struct dso *dso, const char *name,

  	         enum dso_binary_type type)
  {
  	int fd = open(name, O_RDONLY);
  	if (fd < 0)

  		goto out_errno;

  
  	ss->name = strdup(name);
  	if (!ss->name)
  		goto out_close;

  	ss->fd = fd;

  	ss->type = type;
  
  	return 0;
  out_close:
  	close(fd);

  out_errno:
  	dso->load_errno = errno;

  	return -1;
  }

  bool symsrc__possibly_runtime(struct symsrc *ss __maybe_unused)

  {
  	/* Assume all sym sources could be a runtime image. */
  	return true;
  }

  bool symsrc__has_symtab(struct symsrc *ss __maybe_unused)

  {
  	return false;
  }

  void symsrc__destroy(struct symsrc *ss)
  {

  	zfree(&ss->name);

  	close(ss->fd);
  }

  int dso__synthesize_plt_symbols(struct dso *dso __maybe_unused,
  				struct symsrc *ss __maybe_unused,

  				struct map *map __maybe_unused)

  {
  	return 0;
  }

  static int fd__is_64_bit(int fd)
  {
  	u8 e_ident[EI_NIDENT];
  
  	if (lseek(fd, 0, SEEK_SET))
  		return -1;
  
  	if (readn(fd, e_ident, sizeof(e_ident)) != sizeof(e_ident))
  		return -1;
  
  	if (memcmp(e_ident, ELFMAG, SELFMAG) ||
  	    e_ident[EI_VERSION] != EV_CURRENT)
  		return -1;
  
  	return e_ident[EI_CLASS] == ELFCLASS64;
  }

  enum dso_type dso__type_fd(int fd)
  {
  	Elf64_Ehdr ehdr;
  	int ret;
  
  	ret = fd__is_64_bit(fd);
  	if (ret < 0)
  		return DSO__TYPE_UNKNOWN;
  
  	if (ret)
  		return DSO__TYPE_64BIT;
  
  	if (readn(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr))
  		return DSO__TYPE_UNKNOWN;
  
  	if (ehdr.e_machine == EM_X86_64)
  		return DSO__TYPE_X32BIT;
  
  	return DSO__TYPE_32BIT;
  }

  int dso__load_sym(struct dso *dso, struct map *map __maybe_unused,
  		  struct symsrc *ss,
  		  struct symsrc *runtime_ss __maybe_unused,

  		  int kmodule __maybe_unused)

  {

  	unsigned char build_id[BUILD_ID_SIZE];

  	int ret;
  
  	ret = fd__is_64_bit(ss->fd);
  	if (ret >= 0)
  		dso->is_64_bit = ret;

  	if (filename__read_build_id(ss->name, build_id, BUILD_ID_SIZE) > 0) {

  		dso__set_build_id(dso, build_id);

  	}

  	return 0;
  }

  int file__read_maps(int fd __maybe_unused, bool exe __maybe_unused,
  		    mapfn_t mapfn __maybe_unused, void *data __maybe_unused,
  		    bool *is_64_bit __maybe_unused)
  {
  	return -1;
  }

  int kcore_extract__create(struct kcore_extract *kce __maybe_unused)
  {
  	return -1;
  }
  
  void kcore_extract__delete(struct kcore_extract *kce __maybe_unused)
  {
  }

  int kcore_copy(const char *from_dir __maybe_unused,
  	       const char *to_dir __maybe_unused)
  {
  	return -1;
  }

  void symbol__elf_init(void)
  {
  }

  
  char *dso__demangle_sym(struct dso *dso __maybe_unused,
  			int kmodule __maybe_unused,
  			char *elf_name __maybe_unused)
  {
  	return NULL;
  }