From: Christos Zoulas <christos@zoulas.com>
Date: Sat, 5 Oct 1996 18:13:09 +0000 (+0000)
Subject: Initial revision
X-Git-Tag: FILE3_27~74
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=608e4da973296ff476b70444d942b3cb6a872d92;p=file

Initial revision
---

diff --git a/src/readelf.c b/src/readelf.c
new file mode 100644
index 00000000..0d85ff07
--- /dev/null
+++ b/src/readelf.c
@@ -0,0 +1,147 @@
+
+#ifdef BUILTIN_ELF
+#include <stdio.h>
+#include <ctype.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "readelf.h"
+#include "file.h"
+
+static void
+doshn(fd, off, num, size, buf)
+	int fd;
+	off_t off;
+	int num;
+	size_t size;
+	char *buf;
+{
+	/* This works for both 32 and 64 bit elf formats */
+	Elf32_Shdr *sh = (Elf32_Shdr *) buf;
+
+	if (lseek(fd, off, SEEK_SET) == -1)
+		error("lseek failed (%s).\n", strerror(errno));
+
+	for ( ; num; num--) {
+		if (read(fd, buf, size) == -1)
+			error("read failed (%s).\n", strerror(errno));
+		if (sh->sh_type == SHT_SYMTAB)
+			return;
+	}
+	(void) printf (", stripped");
+}
+
+#ifdef notyet
+static void
+dophn(fd, off, num, size, buf)
+	int fd;
+	off_t off;
+	int num;
+	size_t size;
+	char *buf;
+{
+	Elf32_Phdr *ph = (Elf32_Phdr *) buf;
+
+	if (lseek(fd, off, SEEK_SET) == -1)
+		error("lseek failed (%s).\n", strerror(errno));
+
+	for ( ; num; num--) {
+		if (read(fd, buf, size) == -1)
+			error("read failed (%s).\n", strerror(errno));
+		printf("type:%d\n", ph->p_type);
+		if (ph->p_type != PT_NOTE)
+			continue;
+		if (lseek(fd, ph->p_offset, SEEK_SET) == -1)
+			error("lseek failed (%s).\n", strerror(errno));
+		if (size > BUFSIZ)
+			size = BUFSIZ;
+		if (read(fd, buf, size) == -1)
+			error("read failed (%s).\n", strerror(errno));
+		for (size = 0; size < BUFSIZ; size++)
+			if (isalnum(buf[size]))
+				printf("%d %c\n", size, buf[size]);
+		return;
+	}
+}
+#endif
+
+void
+tryelf(fd, buf, nbytes)
+	int fd;
+	char *buf;
+	int nbytes;
+{
+	union {
+		long l;
+		char c[sizeof (long)];
+	} u;
+
+	/*
+	 * ELF executables have multiple section headers in arbitrary
+	 * file locations and thus file(1) cannot determine it from easily.
+	 * Instead we traverse thru all section headers until a symbol table
+	 * one is found or else the binary is stripped.
+	 */
+	if (buf[EI_MAG0] != ELFMAG0 || buf[EI_MAG1] != ELFMAG1
+	    && buf[EI_MAG2] != ELFMAG2 || buf[EI_MAG3] != ELFMAG3)
+	    return;
+
+
+	if (buf[4] == ELFCLASS32) {
+		Elf32_Ehdr elfhdr;
+		if (nbytes <= sizeof (Elf32_Ehdr))
+			return;
+
+
+		u.l = 1;
+		(void) memcpy(&elfhdr, buf, sizeof elfhdr);
+
+#ifdef notyet
+		if (elfhdr.e_type == ET_CORE) 
+			dophn(fd, elfhdr.e_phoff, elfhdr.e_phnum, 
+			      elfhdr.e_phentsize, buf);
+		else 
+#endif
+		{
+			/*
+			 * If the system byteorder does not equal the
+			 * object byteorder then don't test.
+			 */
+			if ((u.c[sizeof(long) - 1] + 1) == elfhdr.e_ident[5])
+				doshn(fd, elfhdr.e_shoff, elfhdr.e_shnum,
+				      elfhdr.e_shentsize, buf);
+		}
+
+		return;
+	}
+
+        if (buf[4] == ELFCLASS64) {
+		Elf64_Ehdr elfhdr;
+		if (nbytes <= sizeof (Elf64_Ehdr))
+			return;
+
+
+		u.l = 1;
+		(void) memcpy(&elfhdr, buf, sizeof elfhdr);
+
+#ifdef notyet
+		if (elfhdr.e_type == ET_CORE) 
+			dophn(fd, elfhdr.e_phoff, elfhdr.e_phnum, 
+			      elfhdr.e_phentsize, buf);
+		else
+#endif
+		{
+			/*
+			 * If the system byteorder does not equal the
+			 * object byteorder then don't test.
+			 */
+			if ((u.c[sizeof(long) - 1] + 1) == elfhdr.e_ident[5])
+				doshn(fd, elfhdr.e_shoff, elfhdr.e_shnum,
+				      elfhdr.e_shentsize, buf);
+		}
+
+		return;
+	}
+}
+#endif