Changeset 48 for trunk/src

Timestamp:

Jun 20, 2006, 10:24:47 PM (18 years ago)

Author:

rainer

Message:

Fix compile problem with sstrip.c

File:

• trunk/src/sstrip.c (modified) (12 diffs)

trunk/src/sstrip.c

@@ -3 +3 @@
  */
 
-/* #include "config_xor.h" */ 
+/* Modified for portability and 64bit/32bit elf executables, Rainer Wichmann */
+ 
+#include "config.h" 
 
 #include        <stdio.h>
@@ -14 +16 @@
 #if !defined(__ia64)  && !defined(__ia64__)  && !defined(__itanium__) &&  \
     !defined(__alpha) && !defined(__alpha__) && \
-    (defined(__linux__) || defined(__FreeBSD__)) && \
-    (defined(__i386__)  || defined(__i386) || defined(i386))
+    (defined(HAVE_ELF_H) || defined(HAVE_LINUX_ELF_H)) && \
+    (defined(__linux__)  || defined(__FreeBSD__)) && \
+    (defined(__i386__)   || defined(__i386) || defined(i386))
 
 /* || defined(__sun) || defined(__sun__) || defined(sun) */
 
-#if defined(__linux__)
+
+#if defined(HAVE_ELF_H)
+#include        <elf.h>
+#else
 #include        <linux/elf.h>
-#else
-#include        <elf.h>
 #endif
 
@@ -30 +34 @@
 #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
+#ifndef ELFCLASS32
+#define ELFCLASS32      1               /* 32-bit objects */
+#endif
+#ifndef ELFCLASS64
+#define ELFCLASS64      2               /* 64-bit objects */
+#endif
+
+
 
 /* The name of the program.
@@ -65 +70 @@
  * munging.
  */
-static int readelfheader(int fd, Elf_Ehdr *ehdr)
+static int readelfheader_32(int fd, Elf32_Ehdr *ehdr)
 {
     errno = 0;
@@ -81 +86 @@
     /* Compare the file's class and endianness with the program's.
      */
+#ifdef ELF_DATA
     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.");
+#endif
+
+    if (ehdr->e_ident[EI_CLASS] != ELFCLASS32)
+        return FALSE;
 
     /* Check the target architecture.
      */
+#ifdef ELF_ARCH
     if (ehdr->e_machine != ELF_ARCH)
         return err("ELF file created for different architecture.");
+#endif
 
     /* Verify the sizes of the ELF header and the program segment
      * header table entries.
      */
-    if (ehdr->e_ehsize != sizeof(Elf_Ehdr))
+    if (ehdr->e_ehsize != sizeof(Elf32_Ehdr))
         return err("unrecognized ELF header size.");
-    if (ehdr->e_phentsize != sizeof(Elf_Phdr))
+    if (ehdr->e_phentsize != sizeof(Elf32_Phdr))
         return err("unrecognized program segment header size.");
 
@@ -107 +117 @@
 }
 
+static int readelfheader_64(int fd, Elf64_Ehdr *ehdr)
+{
+    errno = 0;
+
+    if (lseek(fd, 0, SEEK_SET))
+        return ferr("could not rewind file");
+
+    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.
+     */
+#ifdef ELF_DATA
+    if (ehdr->e_ident[EI_DATA] != ELF_DATA)
+        return err("ELF file has different endianness.");
+#endif
+
+    if (ehdr->e_ident[EI_CLASS] != ELFCLASS64)
+        return err("ELF file has different word size.");
+
+    /* Check the target architecture.
+     */
+#ifdef ELF_ARCH
+    if (ehdr->e_machine != ELF_ARCH)
+        return err("ELF file created for different architecture.");
+#endif
+
+    /* Verify the sizes of the ELF header and the program segment
+     * header table entries.
+     */
+    if (ehdr->e_ehsize != sizeof(Elf64_Ehdr))
+        return err("unrecognized ELF header size.");
+    if (ehdr->e_phentsize != sizeof(Elf64_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)
+static int readphdrtable_32(int fd, Elf32_Ehdr const *ehdr, Elf32_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;
+}
+
+static int readphdrtable_64(int fd, Elf64_Ehdr const *ehdr, Elf64_Phdr **phdrs)
 {
     size_t      size;
@@ -132 +211 @@
  * is executing, and thus can be safely discarded.)
  */
-static int getmemorysize(Elf_Ehdr const *ehdr, Elf_Phdr const *phdrs,
-                         unsigned long *newsize)
-{
-    Elf_Phdr   const   *phdr;
+static int getmemorysize_32(Elf32_Ehdr const *ehdr, Elf32_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;
+}
+
+static int getmemorysize_64(Elf64_Ehdr const *ehdr, Elf64_Phdr const *phdrs,
+                            unsigned long *newsize)
+{
+    Elf64_Phdr   const   *phdr;
+    unsigned long         size, n;
+    int                   i;
 
     /* Start by setting the size to include the ELF header and the
@@ -196 +304 @@
  * included truncated bytes at the end of the file.
  */
-static int modifyheaders(Elf_Ehdr *ehdr, Elf_Phdr *phdrs,
-                         unsigned long newsize)
-{
-    Elf_Phdr   *phdr;
-    int         i;
+static int modifyheaders_32(Elf32_Ehdr *ehdr, Elf32_Phdr *phdrs,
+                            unsigned long newsize)
+{
+    Elf32_Phdr   *phdr;
+    int           i;
 
     /* If the section header table is gone, then remove all references
@@ -228 +336 @@
 }
 
+static int modifyheaders_64(Elf64_Ehdr *ehdr, Elf64_Phdr *phdrs,
+                            unsigned long newsize)
+{
+    Elf64_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)
+static int commitchanges_32(int fd, Elf32_Ehdr const *ehdr, Elf32_Phdr *phdrs,
+                            unsigned long newsize)
 {
     size_t      n;
@@ -275 +415 @@
 }
 
+static int commitchanges_64(int fd, Elf64_Ehdr const *ehdr, Elf64_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.
@@ -281 +465 @@
 {
     int                 fd;
-    Elf_Ehdr            ehdr;
-    Elf_Phdr           *phdrs = NULL;
+    int                 is_32bit_elf;
+    Elf32_Ehdr          ehdr32;
+    Elf32_Phdr         *phdrs32 = NULL;
+    Elf64_Ehdr          ehdr64;
+    Elf64_Phdr         *phdrs64 = NULL;
     unsigned long       newsize;
     char              **arg;
@@ -308 +495 @@
         }
 
-        if (!(readelfheader(fd, &ehdr)                  &&
-              readphdrtable(fd, &ehdr, &phdrs)          &&
-              getmemorysize(&ehdr, phdrs, &newsize)     &&
-              truncatezeros(fd, &newsize)               &&
-              modifyheaders(&ehdr, phdrs, newsize)      &&
-              commitchanges(fd, &ehdr, phdrs, newsize)))
+        if (readelfheader_32(fd, &ehdr32)) {
+          is_32bit_elf = TRUE;
+        } 
+        else if (readelfheader_64(fd, &ehdr64)) {
+          is_32bit_elf = FALSE;
+        }
+        else {
+          close(fd);
+          return EXIT_FAILURE;
+        }
+
+        if (is_32bit_elf) {
+          if (!(readphdrtable_32(fd, &ehdr32, &phdrs32)         &&
+              getmemorysize_32(&ehdr32, phdrs32, &newsize)      &&
+              truncatezeros(fd, &newsize)                       &&
+              modifyheaders_32(&ehdr32, phdrs32, newsize)       &&
+              commitchanges_32(fd, &ehdr32, phdrs32, newsize)))
             ++failures;
+        } 
+        else {
+          if (!(readphdrtable_64(fd, &ehdr64, &phdrs64)         &&
+              getmemorysize_64(&ehdr64, phdrs64, &newsize)      &&
+              truncatezeros(fd, &newsize)                       &&
+              modifyheaders_64(&ehdr64, phdrs64, newsize)       &&
+              commitchanges_64(fd, &ehdr64, phdrs64, newsize)))
+            ++failures;
+        }
 
         close(fd);