aboutsummaryrefslogtreecommitdiff
path: root/sysdeps/generic/readelflib.c
diff options
context:
space:
mode:
Diffstat (limited to 'sysdeps/generic/readelflib.c')
-rw-r--r--sysdeps/generic/readelflib.c220
1 files changed, 220 insertions, 0 deletions
diff --git a/sysdeps/generic/readelflib.c b/sysdeps/generic/readelflib.c
new file mode 100644
index 0000000..26444ad
--- /dev/null
+++ b/sysdeps/generic/readelflib.c
@@ -0,0 +1,220 @@
+/* Copyright (C) 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+ Contributed by Andreas Jaeger <aj@suse.de>, 1999 and
+ Jakub Jelinek <jakub@redhat.com>, 1999.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+/* This code is a heavily simplified version of the readelf program
+ that's part of the current binutils development version. For architectures
+ which need to handle both 32bit and 64bit ELF libraries, this file is
+ included twice for each arch size. */
+
+/* check_ptr checks that a pointer is in the mmaped file and doesn't
+ point outside it. */
+#undef check_ptr
+#define check_ptr(ptr) \
+do \
+ { \
+ if ((void *)(ptr) < file_contents \
+ || (void *)(ptr) > (file_contents+file_length)) \
+ { \
+ error (0, 0, _("file %s is truncated\n"), file_name); \
+ return 1; \
+ } \
+ } \
+ while (0);
+
+/* Returns 0 if everything is ok, != 0 in case of error. */
+int
+process_elf_file (const char *file_name, const char *lib, int *flag,
+ unsigned int *osversion, char **soname, void *file_contents,
+ size_t file_length)
+{
+ int i;
+ unsigned int j;
+ ElfW(Addr) loadaddr;
+ unsigned int dynamic_addr;
+ size_t dynamic_size;
+ char *program_interpreter;
+
+ ElfW(Ehdr) *elf_header;
+ ElfW(Phdr) *elf_pheader, *segment;
+ ElfW(Dyn) *dynamic_segment, *dyn_entry;
+ char *dynamic_strings;
+
+ elf_header = (ElfW(Ehdr) *) file_contents;
+ *osversion = 0;
+
+ if (elf_header->e_ident [EI_CLASS] != ElfW (CLASS))
+ {
+ if (opt_verbose)
+ {
+ if (elf_header->e_ident [EI_CLASS] == ELFCLASS32)
+ error (0, 0, _("%s is a 32 bit ELF file.\n"), file_name);
+ else if (elf_header->e_ident [EI_CLASS] == ELFCLASS64)
+ error (0, 0, _("%s is a 64 bit ELF file.\n"), file_name);
+ else
+ error (0, 0, _("Unknown ELFCLASS in file %s.\n"), file_name);
+ }
+ return 1;
+ }
+
+ if (elf_header->e_type != ET_DYN)
+ {
+ error (0, 0, _("%s is not a shared object file (Type: %d).\n"), file_name,
+ elf_header->e_type);
+ return 1;
+ }
+
+ /* Get information from elf program header. */
+ elf_pheader = (ElfW(Phdr) *) (elf_header->e_phoff + file_contents);
+ check_ptr (elf_pheader);
+
+ /* The library is an elf library, now search for soname and
+ libc5/libc6. */
+ *flag = FLAG_ELF;
+
+ loadaddr = -1;
+ dynamic_addr = 0;
+ dynamic_size = 0;
+ program_interpreter = NULL;
+ for (i = 0, segment = elf_pheader;
+ i < elf_header->e_phnum; i++, segment++)
+ {
+ check_ptr (segment);
+
+ switch (segment->p_type)
+ {
+ case PT_LOAD:
+ if (loadaddr == (ElfW(Addr)) -1)
+ loadaddr = segment->p_vaddr - segment->p_offset;
+ break;
+
+ case PT_DYNAMIC:
+ if (dynamic_addr)
+ error (0, 0, _("more than one dynamic segment\n"));
+
+ dynamic_addr = segment->p_offset;
+ dynamic_size = segment->p_filesz;
+ break;
+
+ case PT_INTERP:
+ program_interpreter = (char *) (file_contents + segment->p_offset);
+ check_ptr (program_interpreter);
+
+ /* Check if this is enough to classify the binary. */
+ for (j = 0; j < sizeof (interpreters) / sizeof (interpreters [0]);
+ ++j)
+ if (strcmp (program_interpreter, interpreters[j].soname) == 0)
+ {
+ *flag = interpreters[j].flag;
+ break;
+ }
+ break;
+
+ case PT_NOTE:
+ if (!*osversion && segment->p_filesz == 32 && segment->p_align >= 4)
+ {
+ ElfW(Word) *abi_note = (ElfW(Word) *) (file_contents
+ + segment->p_offset);
+ if (abi_note [0] == 4 && abi_note [1] == 16 && abi_note [2] == 1
+ && memcmp (abi_note + 3, "GNU", 4) == 0)
+ *osversion = (abi_note [4] << 24) |
+ ((abi_note [5] & 0xff) << 16) |
+ ((abi_note [6] & 0xff) << 8) |
+ (abi_note [7] & 0xff);
+ }
+ break;
+
+ default:
+ break;
+ }
+
+ }
+ if (loadaddr == (ElfW(Addr)) -1)
+ {
+ /* Very strange. */
+ loadaddr = 0;
+ }
+
+ /* Now we can read the dynamic sections. */
+ if (dynamic_size == 0)
+ return 1;
+
+ dynamic_segment = (ElfW(Dyn) *) (file_contents + dynamic_addr);
+ check_ptr (dynamic_segment);
+
+ /* Find the string table. */
+ dynamic_strings = NULL;
+ for (dyn_entry = dynamic_segment; dyn_entry->d_tag != DT_NULL;
+ ++dyn_entry)
+ {
+ check_ptr (dyn_entry);
+ if (dyn_entry->d_tag == DT_STRTAB)
+ {
+ dynamic_strings = (char *) (file_contents + dyn_entry->d_un.d_val - loadaddr);
+ check_ptr (dynamic_strings);
+ break;
+ }
+ }
+
+ if (dynamic_strings == NULL)
+ return 1;
+
+ /* Now read the DT_NEEDED and DT_SONAME entries. */
+ for (dyn_entry = dynamic_segment; dyn_entry->d_tag != DT_NULL;
+ ++dyn_entry)
+ {
+ if (dyn_entry->d_tag == DT_NEEDED || dyn_entry->d_tag == DT_SONAME)
+ {
+ char *name = dynamic_strings + dyn_entry->d_un.d_val;
+ check_ptr (name);
+
+ if (dyn_entry->d_tag == DT_NEEDED)
+ {
+
+ if (*flag == FLAG_ELF)
+ {
+ /* Check if this is enough to classify the binary. */
+ for (j = 0;
+ j < sizeof (known_libs) / sizeof (known_libs [0]);
+ ++j)
+ if (strcmp (name, known_libs [j].soname) == 0)
+ {
+ *flag = known_libs [j].flag;
+ break;
+ }
+ }
+ }
+
+ else if (dyn_entry->d_tag == DT_SONAME)
+ *soname = xstrdup (name);
+
+ /* Do we have everything we need? */
+ if (*soname && *flag != FLAG_ELF)
+ return 0;
+ }
+ }
+
+ /* We reach this point only if the file doesn't contain a DT_SONAME
+ or if we can't classify the library. If it doesn't have a
+ soname, return the name of the library. */
+ if (*soname == NULL)
+ *soname = xstrdup (lib);
+
+ return 0;
+}
generated by cgit v1.1 at 2024-11-03 16:46:39 +0000