/* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*- * * Copyright (c) 2008 Apple Inc. All rights reserved. * * @APPLE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this * file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_LICENSE_HEADER_END@ */ #include <vector> #include "MachOFileAbstraction.hpp" #include "MachOTrie.hpp" #include "prune_trie.h" /* * prune_trie() is a C vended function that is used by strip(1) to prune out * defined exported symbols from the export trie. It is passed a pointer to * the start of bytes of the the trie and the size. The prune() funciton * passed is called with each symbol name in the trie to determine if it is * to be pruned (retuning 1) or not (returning 0). It writes the new trie * back into the trie buffer and returns the new size in trie_new_size. * If the pruning succeeds, NULL is returned. If there was an error processing * the trie (e.f. it is malformed), then an error message string is returned. * The error string can be freed. */ const char* prune_trie( uint8_t* trie_start, uint32_t trie_start_size, int (*prune)(const char *name), uint32_t* trie_new_size) { // convert trie to vector of entries std::vector<mach_o::trie::Entry> originalExports; try { parseTrie(trie_start, trie_start+trie_start_size, originalExports); } catch (const char* msg) { return strdup(msg); } catch (...) { return strdup("unexpected exception processing trie"); } // prune entries into new vector of entries std::vector<mach_o::trie::Entry> newExports; newExports.reserve(originalExports.size()); for(std::vector<mach_o::trie::Entry>::iterator it = originalExports.begin(); it != originalExports.end(); ++it) { if ( prune(it->name) == 0 ) newExports.push_back(*it); } // create new export trie std::vector<uint8_t> newExportTrieBytes; newExportTrieBytes.reserve(trie_start_size); mach_o::trie::makeTrie(newExports, newExportTrieBytes); // Need to align trie to 8 or 4 bytes. We don't know the arch, but if the incoming trie // was not 8-byte aligned, then it can't be a 64-bit arch, so use 4-byte alignement. if ( (trie_start_size % 8) != 0 ) { // 4-byte align while ( (newExportTrieBytes.size() % 4 ) != 0) newExportTrieBytes.push_back(0); } else { // 8-byte align while ( (newExportTrieBytes.size() % 8 ) != 0) newExportTrieBytes.push_back(0); } // copy into place, zero pad *trie_new_size = newExportTrieBytes.size(); if ( *trie_new_size > trie_start_size ) { char* msg; asprintf(&msg, "new trie is larger (%d) than original (%d)", *trie_new_size, trie_start_size); return msg; } memcpy(trie_start, &newExportTrieBytes[0], *trie_new_size); bzero(trie_start+*trie_new_size, trie_start_size - *trie_new_size); // success return NULL; }