add debug option to log hash failures

Makefile.am

@@ -2,7 +2,7 @@ ACLOCAL_AMFLAGS = -I m4
 
 #DISTCHECK_CONFIGURE_FLAGS = --enable-tests
 
-SUBDIRS = include/libtorrent src examples test bindings
+SUBDIRS = include/libtorrent src examples test bindings tools
 
 DOCS_IMAGES = \
   docs/arctic_thumb.png           \

src/smart_ban.cpp

@@ -61,6 +61,55 @@ POSSIBILITY OF SUCH DAMAGE.
 #include "libtorrent/peer_info.hpp"
 #include "libtorrent/random.hpp"
 
+//#define TORRENT_LOG_HASH_FAILURES
+
+#ifdef TORRENT_LOG_HASH_FAILURES
+
+#include "libtorrent/peer_id.hpp" // sha1_hash
+#include "libtorrent/escape_string.hpp" // to_hex
+
+void log_hash_block(FILE** f, libtorrent::torrent const& t, int piece, int block
+	, libtorrent::address a, char const* bytes, int len, bool corrupt)
+{
+	using namespace libtorrent;
+
+	mkdir("hash_failures", 0755);
+
+	if (*f == NULL)
+	{
+		char filename[1024];
+		snprintf(filename, sizeof(filename), "hash_failures/%s.log"
+			, to_hex(t.info_hash().to_string()).c_str());
+		*f = fopen(filename, "w");
+	}
+
+	file_storage const& fs = t.torrent_file().files();
+	std::vector<file_slice> files = fs.map_block(piece, block * 0x4000, len);
+	
+	std::string fn = fs.file_path(fs.internal_at(files[0].file_index));
+
+	char filename[4094];
+	int offset = 0;
+	for (int i = 0; i < files.size(); ++i)
+	{
+		offset += snprintf(filename+offset, sizeof(filename)-offset
+			, "%s[%"PRId64",%d]", libtorrent::filename(fn).c_str(), files[i].offset, int(files[i].size));
+		if (offset >= sizeof(filename)) break;
+	}
+
+	fprintf(*f, "%s\t%04d\t%04d\t%s\t%s\t%s\n", to_hex(t.info_hash().to_string()).c_str(), piece
+		, block, corrupt ? " bad" : "good", print_address(a).c_str(), filename);
+
+	snprintf(filename, sizeof(filename), "hash_failures/%s_%d_%d_%s.block"
+		, to_hex(t.info_hash().to_string()).c_str(), piece, block, corrupt ? "bad" : "good");
+	FILE* data = fopen(filename, "w+");
+	fwrite(bytes, 1, len, data);
+	fclose(data);
+}
+
+#endif
+
+
 namespace libtorrent {
 
 	class torrent;
@@ -74,8 +123,16 @@ namespace
 			: m_torrent(t)
 			, m_salt(random())
 		{
+#ifdef TORRENT_LOG_HASH_FAILURES
+			m_log_file = NULL;
+#endif
 		}
 
+#ifdef TORRENT_LOG_HASH_FAILURES
+		~smart_ban_plugin()
+		{ fclose(m_log_file); }
+#endif
+
 		void on_piece_pass(int p)
 		{
 #ifdef TORRENT_LOGGING
@@ -190,6 +247,11 @@ namespace
 			policy::peer* p = (*range.first);
 			block_entry e = {p, h.final()};
 
+#ifdef TORRENT_LOG_HASH_FAILURES
+			log_hash_block(&m_log_file, m_torrent, b.piece_index
+				, b.block_index, p->address(), j.buffer, j.buffer_size, true);
+#endif
+
 			std::map<piece_block, block_entry>::iterator i = m_block_hashes.lower_bound(b);
 
 			if (i != m_block_hashes.end() && i->first == b && i->second.peer == p)
@@ -263,9 +325,14 @@ namespace
 			h.update((char const*)&m_salt, sizeof(m_salt));
 			sha1_hash ok_digest = h.final();
 
+			policy::peer* p = b.second.peer;
+
 			if (b.second.digest == ok_digest) return;
 
-			policy::peer* p = b.second.peer;
+#ifdef TORRENT_LOG_HASH_FAILURES
+			log_hash_block(&m_log_file, m_torrent, b.first.piece_index
+				, b.first.block_index, p->address(), j.buffer, j.buffer_size, false);
+#endif
 
 			if (p == 0) return;
 			if (!m_torrent.get_policy().has_peer(p)) return;
@@ -302,6 +369,10 @@ namespace
 		// the salt is required to avoid attacks where bad data is sent
 		// that is forged to match the CRC of the good data.
 		int m_salt;
+
+#ifdef TORRENT_LOG_HASH_FAILURES
+		FILE* m_log_file;
+#endif
 	};
 
 } }

tools/Makefile.am

@@ -0,0 +1,20 @@
+tool_programs =  \
+  parse_hash_fails
+
+if ENABLE_EXAMPLES
+bin_PROGRAMS = $(tool_programs)
+endif
+
+EXTRA_PROGRAMS = $(tool_programs)
+EXTRA_DIST = Jamfile
+
+parse_hash_fails_SOURCES = parse_hash_fails.cpp
+#client_test_LDADD = $(top_builddir)/src/libtorrent-rasterbar.la
+
+LDADD = $(top_builddir)/src/libtorrent-rasterbar.la
+
+AM_CPPFLAGS = -ftemplate-depth-50 -I$(top_srcdir)/include @DEBUGFLAGS@
+
+#AM_LDFLAGS = ${LDLAGS} -L./ @BOOST_SYSTEM_LIB@ @OPENSSL_LDFLAGS@ @OPENSSL_LIBS@
+#AM_LDFLAGS = $(LDFLAGS) @BOOST_SYSTEM_LIB@ @OPENSSL_LDFLAGS@ @OPENSSL_LIBS@
+#AM_LDFLAGS = @OPENSSL_LDFLAGS@

tools/parse_hash_fails.cpp

@@ -0,0 +1,103 @@
+/*
+
+Copyright (c) 2012, Arvid Norberg
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions
+are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in
+      the documentation and/or other materials provided with the distribution.
+    * Neither the name of the author nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+*/
+
+#include <stdlib.h>
+#include <string>
+#include "libtorrent/file.hpp"
+
+using namespace libtorrent;
+
+void print_usage()
+{
+	fprintf(stderr, "usage: parse_hash_fails log-directory\n");
+	exit(1);
+}
+
+int main(int argc, char* argv[])
+{
+	if (argc != 2) print_usage();
+
+	error_code ec;
+	directory d(argv[1], ec);
+	if (ec)
+	{
+		fprintf(stderr, "failed to open directory: %s\n%s\n"
+			, argv[1], ec.message().c_str());
+		return 1;
+	}
+
+	for (; !d.done(); d.next(ec))
+	{
+		if (ec)
+		{
+			fprintf(stderr, "error listing directory: %s\n", ec.message().c_str());
+			return 1;
+		}
+		std::string filename = d.file();
+		char hash[41];
+		int piece;
+		int block;
+		char state[10]; // good, bad
+		if (sscanf(filename.c_str(), "%40s_%d_%d_%4s.block", hash, &piece, &block, state) != 4)
+		{
+			fprintf(stderr, "no match: %s\n", filename.c_str());
+			continue;
+		}
+
+		if (strcmp(state, "good") != 0) continue;
+
+		char target_filename[1024];
+		snprintf(target_filename, sizeof(target_filename), "%s_%d_%d.diff", hash, piece, block);
+
+		fprintf(stderr, "diffing %s\n", filename.c_str());
+		char cmdline[2048];
+		snprintf(cmdline, sizeof(cmdline), "xxd %s >temp_good", combine_path(argv[1], filename).c_str());
+		system(cmdline);
+		snprintf(cmdline, sizeof(cmdline), "xxd %s/%s_%d_%d_bad.block >temp_bad", argv[1], hash, piece, block);
+		system(cmdline);
+		snprintf(cmdline, sizeof(cmdline), "diff -y temp_good temp_bad | colordiff >%s"
+			, combine_path(argv[1], target_filename).c_str());
+		system(cmdline);
+	}
+
+	FILE* log_file = fopen(argv[1], "r");
+	if (log_file == 0)
+	{
+		fprintf(stderr, "failed to open logfile: %s\n%d: %s\n"
+			, argv[1], errno, strerror(errno));
+		return 1;
+	}
+
+	return 0;
+}
+
+