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

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;
+}