still need to fix dynamic linling string table

Author: SravanthiSinha

0x06-readelf/Makefile

@@ -1,5 +1,5 @@
-CC 	= 	gcc-4.8
-CFLAGS 	= 	-Wall -Werror -Wextra -pedantic -g
+# CC 	= 	gcc-4.8
+# CFLAGS 	= 	-Wall -Werror -Wextra -pedantic -g
 
 _SRC 	= 	0-hreadelf.c \
 		validate_elf.c \
@@ -25,12 +25,24 @@ _SRC2 	= 	2-hreadelf.c \
 			process_elf_section_header.c \
 			process_elf_program_header.c
 
+_SRC3 	= 	100-hreadelf.c \
+			validate_elf.c \
+			elf_utils.c \
+			elf_utils2.c \
+			elf_utils3.c \
+			elf_utils4.c \
+			process_elf_header.c \
+			process_elf_section_header.c \
+			process_elf_symbol_tables.c
+
 SRC 	= 	$(patsubst %,$(SDIR)/%,$(_SRC))
 
 SRC1 	= 	$(patsubst %,$(SDIR)/%,$(_SRC1))
 
 SRC2 	= 	$(patsubst %,$(SDIR)/%,$(_SRC2))
 
+SRC3 	= 	$(patsubst %,$(SDIR)/%,$(_SRC3))
+
 _OBJ 	= 	$(_SRC:.c=.o)
 OBJECTS 	= 	$(patsubst %,$(ODIR)/%,$(_OBJ))
 
@@ -40,6 +52,9 @@ OBJECTS1 	= 	$(patsubst %,$(ODIR)/%,$(_OBJ1))
 _OBJ2 	= 	$(_SRC2:.c=.o)
 OBJECTS2 	= 	$(patsubst %,$(ODIR)/%,$(_OBJ2))
 
+_OBJ3 	= 	$(_SRC3:.c=.o)
+OBJECTS3 	= 	$(patsubst %,$(ODIR)/%,$(_OBJ3))
+
 _DEPS 	=	readelf.h
 DEPS 	= 	$(patsubst %,$(IDIR)/%,$(_DEPS))
 
@@ -50,11 +65,12 @@ ODIR 	= 	.
 OUTPUT 	= 	0-hreadelf
 OUTPUT1 	= 	1-hreadelf
 OUTPUT2 	= 	2-hreadelf
+OUTPUT3 	= 	100-hreadelf
 
 $(ODIR)/%.o : $(SDIR)/%.c
 	$(CC) $(CFLAGS) -c -o $@ $< -I$(IDIR)
 
-all : $(OUTPUT1) $(OUTPUT) $(OUTPUT2)
+all : $(OUTPUT1) $(OUTPUT) $(OUTPUT2) $(OUTPUT3)
 
 $(OUTPUT) : $(OBJECTS)
 	$(CC) -o $@ $^ $(LINKS)
@@ -64,9 +80,13 @@ $(OUTPUT1) : $(OBJECTS1)
 
 $(OUTPUT2) : $(OBJECTS2)
 	$(CC) -o $@ $^ $(LINKS)
+
+$(OUTPUT3) : $(OBJECTS3)
+	$(CC) -o $@ $^ $(LINKS)
+
 .PHONY : clean
 
 clean :
-	rm -f $(OUTPUT) $(OUTPUT1) $(OBJECTS) $(OBJECTS1) $(OUTPUT2) $(OBJECTS2)
+	rm -f $(OUTPUT) $(OUTPUT1) $(OUTPUT3) $(OBJECTS) $(OBJECTS1) $(OUTPUT2) $(OBJECTS2) $(OBJECTS3)
 
-re: $(OBJ) $(OBJ1) $(OBJ2)
+re: $(OBJ) $(OBJ1) $(OBJ2) $(OBJ3)

0x06-readelf/README.md

@@ -19,6 +19,12 @@ Usage: 2-hreadelf elf_filename
 ```
 standard output, error output and status are the exact same as readelf -W -l
 
+100-hreadelf - a program that displays the information contained in the ELF symbol tables of an ELF file.
+```
+Usage: 100-hreadelf elf_filename
+```
+standard output, error output and status are the exact same as readelf -W -s
+
 ## Useful Resources:
 * man elf(5), man readelf(1)
 * See also /usr/include/elf.h

0x06-readelf/inc/readelf.h

@@ -111,10 +111,30 @@ typedef struct phdr
 	uint64_t p_align;
 } ElfN_Phdr;
 
+/**
+ * struct symtab-  Symbol table entry
+ * @st_name : Symbol name, index in string tbl
+ * @st_info : Type and binding attributes
+ * @st_other :  No defined meaning, 0
+ * @st_shndx : Associated section index
+ * @st_value : Value of the symbol
+ * @st_size : Associated symbol size
+ */
+typedef struct symtab
+{
+	uint64_t st_name;
+	unsigned char st_info;
+	unsigned char st_other;
+	uint16_t st_shndx;
+	uint64_t st_value;
+	uint64_t st_size;
+} ElfN_Sym;
+
 #define SHF_X86_64_LARGE 0x10000000
 #define GET_BYTE(field) get_byte(field, sizeof(field))
 #define E "Error: Not an ELF file - it has the wrong magic bytes at the start"
-
+#define ELF_ST_BIND(x)		((x) >> 4)
+#define ELF_ST_TYPE(x)		(((unsigned int) x) & 0xf)
 #define ELF_SECTION_SIZE(sec_hdr, segment)			\
 	(((sec_hdr.sh_flags & SHF_TLS) == 0			\
 	  || sec_hdr.sh_type != SHT_NOBITS			\
@@ -147,6 +167,10 @@ char *get_elf_class(unsigned int elf_class);
 char *get_section_type_name(unsigned int sh_type);
 char *get_elf_section_flags(ElfN_Ehdr elf_header, unsigned long sh_flags);
 char *get_segment_type(unsigned long p_type);
+char *get_symbol_binding(unsigned int binding);
+char *get_symbol_type(unsigned int type);
+char *get_symbol_visibility(unsigned int visibility);
+char *get_symbol_index_type(unsigned int type);
 
 char *get_vma(unsigned int no, char format, char end);
 uint64_t get_byte_big_endian(uint64_t data, int size);
@@ -165,8 +189,13 @@ void read_elf_program_header_N(ElfN_Ehdr *ehdr, FILE *file, int arch);
 void read_elf_program_header_32(ElfN_Ehdr eh, ElfN_Phdr *phdr_tbl, int fd);
 void read_elf_program_header_64(ElfN_Ehdr eh, ElfN_Phdr *phdr_tbl, int fd);
 
+void read_elf_symbol_table_N(ElfN_Ehdr *ehdr, FILE *file, int arch);
+
 void print_elf_header(ElfN_Ehdr ehdr);
 void print_elf_section_header(ElfN_Shdr *shdr_tbl, ElfN_Ehdr eh, int fd);
 void print_elf_program_header(ElfN_Phdr ph_tbl[], ElfN_Shdr sh_tbl[],
 			      ElfN_Ehdr ehdr, FILE *file);
+void print_elf_symbol_table(ElfN_Shdr sh_tbl[], ElfN_Sym sym_tbl[],
+			    ElfN_Ehdr ehdr, int sym_tbl_indx, uint64_t count,
+			    int fd);
 #endif

0x06-readelf/src/1-hreadelf.c

@@ -2,7 +2,7 @@
 
 /**
  * main - A program that takes the name of a elf file as a parameter and
- * displays the information contained in the ELF file header of an ELF file.
+ * displays the information contained in section headers of an  ELF file.
  * @argc: no of inputs.
  * @argv: inputs.
  *

0x06-readelf/src/100-hreadelf.c

@@ -0,0 +1,43 @@
+#include "readelf.h"
+
+/**
+ * main - A program that takes the name of a elf file as a parameter and
+ * displays the information contained in Symbol tables of an ELF file.
+ * @argc: no of inputs.
+ * @argv: inputs.
+ *
+ * Return: on success:  0 , on Failure: 1.
+ */
+int main(int argc, char *argv[])
+{
+	ElfN_Ehdr ehdr;
+	int exit_status = 0, arch = 0;
+	FILE *file;
+
+	/* validate user input */
+	if (argc < 2)
+	{
+		printf("Usage: %s elf_filename\n", argv[0]);
+		exit(1);
+	}
+	/* open the elf file */
+	file = fopen(argv[1], "rb");
+	if (file)
+	{
+		if (fread(ehdr.e_ident, EI_NIDENT, 1, file) &&
+		    elf_check_file(ehdr.e_ident))
+		{
+			get_architecture(ehdr.e_ident[EI_CLASS], &arch);
+			read_elf_symbol_table_N(&ehdr, file, arch);
+		} else
+			printf("%s: %s\n", E, argv[0]);
+		exit_status = 1;
+		/* finally close the file*/
+		fclose(file);
+	} else
+	{
+		printf("%s: Error: '%s': No such file\n", argv[0], argv[1]);
+		exit_status = 1;
+	}
+	return (exit_status);
+}

0x06-readelf/src/2-hreadelf.c

@@ -2,7 +2,7 @@
 
 /**
  * main - A program that takes the name of a elf file as a parameter and
- * displays the information contained in the ELF file header of an ELF file.
+ * displays the information contained in the program header of an ELF file.
  * @argc: no of inputs.
  * @argv: inputs.
  *

0x06-readelf/src/elf_utils4.c

@@ -0,0 +1,108 @@
+#include "readelf.h"
+
+/**
+ * get_symbol_type - gets the symbol type
+ * @type: symbol type of elf
+ * Return: symbol type of elf
+ */
+char *get_symbol_type(unsigned int type)
+{
+	char buff[32];
+
+	switch (type)
+	{
+	case STT_NOTYPE:
+		return ("NOTYPE");
+	case STT_OBJECT:
+		return ("OBJECT");
+	case STT_FUNC:
+		return ("FUNC");
+	case STT_SECTION:
+		return ("SECTION");
+	case STT_FILE:
+		return ("FILE");
+	case STT_COMMON:
+		return ("COMMON");
+	case STT_TLS:
+		return ("TLS");
+	default:
+		return ("NOTYPE");
+	}
+}
+
+/**
+ * get_symbol_binding - gets the binding type
+ * @binding: binding type of elf
+ * Return: binding type of elf
+ */
+char *get_symbol_binding(unsigned int binding)
+{
+	char buff[32];
+
+	switch (binding)
+	{
+	case STB_LOCAL:
+		return ("LOCAL");
+	case STB_GLOBAL:
+		return ("GLOBAL");
+	case STB_WEAK:
+		return ("WEAK");
+	default:
+		snprintf(buff, sizeof(buff), ("<unknown>: %d"), binding);
+		return (strdup(buff));
+	}
+}
+
+/**
+ * get_symbol_visibility - gets the visibility type
+ * @visibility: visibility type of elf
+ * Return: visibility type of elf
+ */
+char *get_symbol_visibility(unsigned int visibility)
+{
+	switch (visibility)
+	{
+	case STV_DEFAULT:
+		return ("DEFAULT");
+	case STV_INTERNAL:
+		return ("INTERNAL");
+	case STV_HIDDEN:
+		return ("HIDDEN");
+	case STV_PROTECTED:
+		return ("PROTECTED");
+	default:
+		abort();
+	}
+}
+
+/**
+ * get_symbol_index_type - gets the symbol index type
+ * @type: type of symbol
+ * Return: symbol index type
+ */
+char *get_symbol_index_type(unsigned int type)
+{
+	char buff[32];
+
+	switch (type)
+	{
+	case SHN_UNDEF:
+		return ("UND");
+	case SHN_ABS:
+		return ("ABS");
+	case SHN_COMMON:
+		return ("COM");
+	default:
+		if (type >= SHN_LOPROC && type <= SHN_HIPROC)
+			sprintf(buff, "PRC[0x%04x]", type);
+		else if (type >= SHN_LOOS && type <= SHN_HIOS)
+			sprintf(buff, "OS [0x%04x]", type);
+		else if (type >= SHN_LORESERVE && type <= SHN_HIRESERVE)
+			sprintf(buff, "RSV[0x%04x]", type);
+		else
+			sprintf(buff, "%3d", type);
+		break;
+	}
+
+	return (strdup(buff));
+}