commit 22fda9910920d7465d1558bd6cf2741177b3b908 Author: David Goulet dgoulet@efficios.com Date: Sat Jul 6 22:33:14 2013 -0400

Add close(2) support

Signed-off-by: David Goulet dgoulet@efficios.com --- src/lib/Makefile.am | 2 +- src/lib/close.c | 64 +++++++++++++++++++++++++++++++++++++++++++++++++++ src/lib/torsocks.c | 2 ++ src/lib/torsocks.h | 14 +++++++++++ 4 files changed, 81 insertions(+), 1 deletion(-)

diff --git a/src/lib/Makefile.am b/src/lib/Makefile.am index bf9237e..ec9ef0f 100644 --- a/src/lib/Makefile.am +++ b/src/lib/Makefile.am @@ -11,7 +11,7 @@ EXTRA_DIST = torsocks.in usewithtor.in lib_LTLIBRARIES = libtorsocks.la

libtorsocks_la_SOURCES = torsocks.c torsocks.h \ - connect.c gethostbyname.c getaddrinfo.c + connect.c gethostbyname.c getaddrinfo.c close.c

libtorsocks_la_LIBADD = \ $(top_builddir)/src/common/libcommon.la \ diff --git a/src/lib/close.c b/src/lib/close.c new file mode 100644 index 0000000..699b93c --- /dev/null +++ b/src/lib/close.c @@ -0,0 +1,64 @@ +/* + * Copyright (C) 2013 - David Goulet dgoulet@ev0ke.net + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License, version 2 only, as + * published by the Free Software Foundation. + * + * This program 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 General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., 51 + * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <common/connection.h> +#include <common/log.h> + +#include "torsocks.h" + +/* + * Torsocks call for close(2). + */ +LIBC_CLOSE_RET_TYPE tsocks_close(LIBC_CLOSE_SIG) +{ + struct connection *conn; + + DBG("Close catched for fd %d", __fd); + + connection_registry_lock(); + conn = connection_find(__fd); + if (conn) { + /* + * Remove from the registry so it's not visible anymore and thus using + * it without lock. + */ + connection_remove(conn); + } + connection_registry_unlock(); + + /* + * Put back the connection reference. If the refcount get to 0, the + * connection pointer is destroyed. + */ + if (conn) { + DBG("Close connection putting back ref"); + connection_put_ref(conn); + } + + /* Return the original libc close. */ + return tsocks_libc_close(__fd); +} + +/* + * Libc hijacked symbol close(2). + */ +LIBC_CLOSE_DECL +{ + tsocks_libc_close = tsocks_find_libc_symbol(LIBC_CLOSE_NAME_STR, + TSOCKS_SYM_EXIT_NOT_FOUND); + return tsocks_close(LIBC_CLOSE_ARGS); +} diff --git a/src/lib/torsocks.c b/src/lib/torsocks.c index f40de3c..cf287d9 100644 --- a/src/lib/torsocks.c +++ b/src/lib/torsocks.c @@ -121,6 +121,8 @@ static void init_libc_symbols(void) { tsocks_libc_connect = tsocks_find_libc_symbol(LIBC_CONNECT_NAME_STR, TSOCKS_SYM_EXIT_NOT_FOUND); + tsocks_libc_close = tsocks_find_libc_symbol(LIBC_CLOSE_NAME_STR, + TSOCKS_SYM_EXIT_NOT_FOUND); }

/* diff --git a/src/lib/torsocks.h b/src/lib/torsocks.h index 2d40470..4acacff 100644 --- a/src/lib/torsocks.h +++ b/src/lib/torsocks.h @@ -45,6 +45,15 @@ #define LIBC_CONNECT_ARGS \ __sockfd, __addr, __addrlen

+/* close(2) */ +#include <unistd.h> + +#define LIBC_CLOSE_NAME close +#define LIBC_CLOSE_NAME_STR XSTR(LIBC_CLOSE_NAME) +#define LIBC_CLOSE_RET_TYPE int +#define LIBC_CLOSE_SIG int __fd +#define LIBC_CLOSE_ARGS __fd + /* gethostbyname(3) - DEPRECATED in glibc. */ #include <netdb.h>

@@ -106,6 +115,11 @@ TSOCKS_LIBC_DECL(connect, LIBC_CONNECT_RET_TYPE, LIBC_CONNECT_SIG) #define LIBC_CONNECT_DECL \ LIBC_CONNECT_RET_TYPE LIBC_CONNECT_NAME(LIBC_CONNECT_SIG)

+/* close(2) */ +TSOCKS_LIBC_DECL(close, LIBC_CLOSE_RET_TYPE, LIBC_CLOSE_SIG) +#define LIBC_CLOSE_DECL \ + LIBC_CLOSE_RET_TYPE LIBC_CLOSE_NAME(LIBC_CLOSE_SIG) + /* gethostbyname(3) */ TSOCKS_LIBC_DECL(gethostbyname, LIBC_GETHOSTBYNAME_RET_TYPE, LIBC_GETHOSTBYNAME_SIG)