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authormbm <mbm@3c298f89-4303-0410-b956-a3cf2f4a3e73>2004-08-17 23:00:52 +0000
committermbm <mbm@3c298f89-4303-0410-b956-a3cf2f4a3e73>2004-08-17 23:00:52 +0000
commitb46fe1c707bc971ac7c06b7545b21c666349f7f9 (patch)
tree84ebc770984bae282956c67d6b0b2234b2a56a70 /obsolete-buildroot/sources/openwrt/tools/sstrip.c
parente2784f3bce41605cdae551531a6621ae9c1c043d (diff)
sstrip, nas support, mppe support, mac os x patches, syslogd on bootup, inittab correction
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@136 3c298f89-4303-0410-b956-a3cf2f4a3e73
Diffstat (limited to 'obsolete-buildroot/sources/openwrt/tools/sstrip.c')
-rw-r--r--obsolete-buildroot/sources/openwrt/tools/sstrip.c327
1 files changed, 327 insertions, 0 deletions
diff --git a/obsolete-buildroot/sources/openwrt/tools/sstrip.c b/obsolete-buildroot/sources/openwrt/tools/sstrip.c
new file mode 100644
index 000000000..32769fff6
--- /dev/null
+++ b/obsolete-buildroot/sources/openwrt/tools/sstrip.c
@@ -0,0 +1,327 @@
+/* http://www.muppetlabs.com/~breadbox/software/elfkickers.html */
+
+/* sstrip: Copyright (C) 1999-2001 by Brian Raiter, under the GNU
+ * General Public License. No warranty. See COPYING for details.
+ */
+
+#define __MIPSEL__ 1
+#define _MIPS_SZLONG 32
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <elf.h>
+#include <linux/bitops.h>
+
+typedef signed char s8;
+typedef unsigned char u8;
+
+typedef signed short s16;
+typedef unsigned short u16;
+
+typedef signed int s32;
+typedef unsigned int u32;
+
+typedef signed long long s64;
+typedef unsigned long long u64;
+
+#include <asm/elf.h>
+
+#ifndef TRUE
+#define TRUE 1
+#define FALSE 0
+#endif
+
+#if ELF_CLASS == ELFCLASS32
+#define Elf_Ehdr Elf32_Ehdr
+#define Elf_Phdr Elf32_Phdr
+#else
+#define Elf_Ehdr Elf64_Ehdr
+#define Elf_Phdr Elf64_Phdr
+#endif
+
+/* The name of the program.
+ */
+static char const *progname;
+
+/* The name of the current file.
+ */
+static char const *filename;
+
+
+/* A simple error-handling function. FALSE is always returned for the
+ * convenience of the caller.
+ */
+static int err(char const *errmsg)
+{
+ fprintf(stderr, "%s: %s: %s\n", progname, filename, errmsg);
+ return FALSE;
+}
+
+/* A macro for I/O errors: The given error message is used only when
+ * errno is not set.
+ */
+#define ferr(msg) (err(errno ? strerror(errno) : (msg)))
+
+/* readelfheader() reads the ELF header into our global variable, and
+ * checks to make sure that this is in fact a file that we should be
+ * munging.
+ */
+static int readelfheader(int fd, Elf_Ehdr *ehdr)
+{
+ errno = 0;
+ if (read(fd, ehdr, sizeof *ehdr) != sizeof *ehdr)
+ return ferr("missing or incomplete ELF header.");
+
+ /* Check the ELF signature.
+ */
+ if (!(ehdr->e_ident[EI_MAG0] == ELFMAG0 &&
+ ehdr->e_ident[EI_MAG1] == ELFMAG1 &&
+ ehdr->e_ident[EI_MAG2] == ELFMAG2 &&
+ ehdr->e_ident[EI_MAG3] == ELFMAG3))
+ return err("missing ELF signature.");
+
+ /* Compare the file's class and endianness with the program's.
+ */
+ if (ehdr->e_ident[EI_DATA] != ELF_DATA)
+ return err("ELF file has different endianness.");
+ if (ehdr->e_ident[EI_CLASS] != ELF_CLASS)
+ return err("ELF file has different word size.");
+
+ /* Check the target architecture.
+ */
+ if (ehdr->e_machine != ELF_ARCH)
+ return err("ELF file created for different architecture.");
+ /* Verify the sizes of the ELF header and the program segment
+ * header table entries.
+ */
+ if (ehdr->e_ehsize != sizeof(Elf_Ehdr))
+ return err("unrecognized ELF header size.");
+ if (ehdr->e_phentsize != sizeof(Elf_Phdr))
+ return err("unrecognized program segment header size.");
+
+ /* Finally, check the file type.
+ */
+ if (ehdr->e_type != ET_EXEC && ehdr->e_type != ET_DYN)
+ return err("not an executable or shared-object library.");
+
+ return TRUE;
+}
+
+/* readphdrtable() loads the program segment header table into memory.
+ */
+static int readphdrtable(int fd, Elf_Ehdr const *ehdr, Elf_Phdr **phdrs)
+{
+ size_t size;
+
+ if (!ehdr->e_phoff || !ehdr->e_phnum)
+ return err("ELF file has no program header table.");
+
+ size = ehdr->e_phnum * sizeof **phdrs;
+ if (!(*phdrs = malloc(size)))
+ return err("Out of memory!");
+
+ errno = 0;
+ if (read(fd, *phdrs, size) != (ssize_t)size)
+ return ferr("missing or incomplete program segment header table.");
+
+ return TRUE;
+}
+
+/* getmemorysize() determines the offset of the last byte of the file
+ * that is referenced by an entry in the program segment header table.
+ * (Anything in the file after that point is not used when the program
+ * is executing, and thus can be safely discarded.)
+ */
+static int getmemorysize(Elf_Ehdr const *ehdr, Elf_Phdr const *phdrs,
+ unsigned long *newsize)
+{
+ Elf32_Phdr const *phdr;
+ unsigned long size, n;
+ int i;
+
+ /* Start by setting the size to include the ELF header and the
+ * complete program segment header table.
+ */
+ size = ehdr->e_phoff + ehdr->e_phnum * sizeof *phdrs;
+ if (size < sizeof *ehdr)
+ size = sizeof *ehdr;
+
+ /* Then keep extending the size to include whatever data the
+ * program segment header table references.
+ */
+ for (i = 0, phdr = phdrs ; i < ehdr->e_phnum ; ++i, ++phdr) {
+ if (phdr->p_type != PT_NULL) {
+ n = phdr->p_offset + phdr->p_filesz;
+ if (n > size)
+ size = n;
+ }
+ }
+
+ *newsize = size;
+ return TRUE;
+}
+
+/* truncatezeros() examines the bytes at the end of the file's
+ * size-to-be, and reduces the size to exclude any trailing zero
+ * bytes.
+ */
+static int truncatezeros(int fd, unsigned long *newsize)
+{
+ unsigned char contents[1024];
+ unsigned long size, n;
+
+ size = *newsize;
+ do {
+ n = sizeof contents;
+ if (n > size)
+ n = size;
+ if (lseek(fd, size - n, SEEK_SET) == (off_t)-1)
+ return ferr("cannot seek in file.");
+ if (read(fd, contents, n) != (ssize_t)n)
+ return ferr("cannot read file contents");
+ while (n && !contents[--n])
+ --size;
+ } while (size && !n);
+
+ /* Sanity check.
+ */
+ if (!size)
+ return err("ELF file is completely blank!");
+
+ *newsize = size;
+ return TRUE;
+}
+
+/* modifyheaders() removes references to the section header table if
+ * it was stripped, and reduces program header table entries that
+ * included truncated bytes at the end of the file.
+ */
+static int modifyheaders(Elf_Ehdr *ehdr, Elf_Phdr *phdrs,
+ unsigned long newsize)
+{
+ Elf32_Phdr *phdr;
+ int i;
+
+ /* If the section header table is gone, then remove all references
+ * to it in the ELF header.
+ */
+ if (ehdr->e_shoff >= newsize) {
+ ehdr->e_shoff = 0;
+ ehdr->e_shnum = 0;
+ ehdr->e_shentsize = 0;
+ ehdr->e_shstrndx = 0;
+ }
+
+ /* The program adjusts the file size of any segment that was
+ * truncated. The case of a segment being completely stripped out
+ * is handled separately.
+ */
+ for (i = 0, phdr = phdrs ; i < ehdr->e_phnum ; ++i, ++phdr) {
+ if (phdr->p_offset >= newsize) {
+ phdr->p_offset = newsize;
+ phdr->p_filesz = 0;
+ } else if (phdr->p_offset + phdr->p_filesz > newsize) {
+ phdr->p_filesz = newsize - phdr->p_offset;
+ }
+ }
+
+ return TRUE;
+}
+
+/* commitchanges() writes the new headers back to the original file
+ * and sets the file to its new size.
+ */
+static int commitchanges(int fd, Elf_Ehdr const *ehdr, Elf_Phdr *phdrs,
+ unsigned long newsize)
+{
+ size_t n;
+
+ /* Save the changes to the ELF header, if any.
+ */
+ if (lseek(fd, 0, SEEK_SET))
+ return ferr("could not rewind file");
+ errno = 0;
+ if (write(fd, ehdr, sizeof *ehdr) != sizeof *ehdr)
+ return err("could not modify file");
+
+ /* Save the changes to the program segment header table, if any.
+ */
+ if (lseek(fd, ehdr->e_phoff, SEEK_SET) == (off_t)-1) {
+ err("could not seek in file.");
+ goto warning;
+ }
+ n = ehdr->e_phnum * sizeof *phdrs;
+ if (write(fd, phdrs, n) != (ssize_t)n) {
+ err("could not write to file");
+ goto warning;
+ }
+
+ /* Eleventh-hour sanity check: don't truncate before the end of
+ * the program segment header table.
+ */
+ if (newsize < ehdr->e_phoff + n)
+ newsize = ehdr->e_phoff + n;
+
+ /* Chop off the end of the file.
+ */
+ if (ftruncate(fd, newsize)) {
+ err("could not resize file");
+ goto warning;
+ }
+
+ return TRUE;
+
+ warning:
+ return err("ELF file may have been corrupted!");
+}
+
+/* main() loops over the cmdline arguments, leaving all the real work
+ * to the other functions.
+ */
+int main(int argc, char *argv[])
+{
+ int fd;
+ Elf_Ehdr ehdr;
+ Elf_Phdr *phdrs;
+ unsigned long newsize;
+ char **arg;
+ int failures = 0;
+
+ if (argc < 2 || argv[1][0] == '-') {
+ printf("Usage: sstrip FILE...\n"
+ "sstrip discards all nonessential bytes from an executable.\n\n"
+ "Version 2.0 Copyright (C) 2000,2001 Brian Raiter.\n"
+ "This program is free software, licensed under the GNU\n"
+ "General Public License. There is absolutely no warranty.\n");
+ return EXIT_SUCCESS;
+ }
+
+ progname = argv[0];
+
+ for (arg = argv + 1 ; *arg != NULL ; ++arg) {
+ filename = *arg;
+
+ fd = open(*arg, O_RDWR);
+ if (fd < 0) {
+ ferr("can't open");
+ ++failures;
+ continue;
+ }
+
+ if (!(readelfheader(fd, &ehdr) &&
+ readphdrtable(fd, &ehdr, &phdrs) &&
+ getmemorysize(&ehdr, phdrs, &newsize) &&
+ truncatezeros(fd, &newsize) &&
+ modifyheaders(&ehdr, phdrs, newsize) &&
+ commitchanges(fd, &ehdr, phdrs, newsize)))
+ ++failures;
+
+ close(fd);
+ }
+
+ return failures ? EXIT_FAILURE : EXIT_SUCCESS;
+}