commit 7dee92c5f0e29222258dd10074bbdf8a008bc749 Author: David Goulet dgoulet@ev0ke.net Date: Sat Mar 8 11:20:07 2014 -0500

Add fclose() support

Fixes #29

Signed-off-by: David Goulet dgoulet@ev0ke.net --- src/lib/Makefile.am | 2 +- src/lib/fclose.c | 85 +++++++++++++++++++++++++++++++++++++++++++++++++++ src/lib/torsocks.h | 15 +++++++++ 3 files changed, 101 insertions(+), 1 deletion(-)

diff --git a/src/lib/Makefile.am b/src/lib/Makefile.am index cccecf1..d64b3f6 100644 --- a/src/lib/Makefile.am +++ b/src/lib/Makefile.am @@ -9,6 +9,6 @@ lib_LTLIBRARIES = libtorsocks.la libtorsocks_la_SOURCES = torsocks.c torsocks.h \ connect.c gethostbyname.c getaddrinfo.c close.c \ getpeername.c socket.c syscall.c socketpair.c recv.c \ - exit.c accept.c listen.c + exit.c accept.c listen.c fclose.c

libtorsocks_la_LIBADD = $(top_builddir)/src/common/libcommon.la diff --git a/src/lib/fclose.c b/src/lib/fclose.c new file mode 100644 index 0000000..8d371cd --- /dev/null +++ b/src/lib/fclose.c @@ -0,0 +1,85 @@ +/* + * Copyright (C) 2014 - 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" + +/* fclose(3) */ +TSOCKS_LIBC_DECL(fclose, LIBC_FCLOSE_RET_TYPE, LIBC_FCLOSE_SIG) + +/* + * Torsocks call for fclose(3). + */ +LIBC_FCLOSE_RET_TYPE tsocks_fclose(LIBC_FCLOSE_SIG) +{ + int fd; + struct connection *conn; + + if (!fp) { + errno = EBADF; + goto error; + } + + fd = fileno(fp); + if (fd < 0) { + /* errno is set to EBADF here by fileno(). */ + goto error; + } + + DBG("[fclose] 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 fclose. */ + return tsocks_libc_fclose(fp); + +error: + return -1; +} + +/* + * Libc hijacked symbol fclose(3). + */ +LIBC_FCLOSE_DECL +{ + if (!tsocks_libc_fclose) { + tsocks_libc_fclose = tsocks_find_libc_symbol( + LIBC_FCLOSE_NAME_STR, TSOCKS_SYM_EXIT_NOT_FOUND); + } + + return tsocks_fclose(LIBC_FCLOSE_ARGS); +} diff --git a/src/lib/torsocks.h b/src/lib/torsocks.h index 1b95cb9..057a32e 100644 --- a/src/lib/torsocks.h +++ b/src/lib/torsocks.h @@ -74,6 +74,15 @@ #define LIBC_CLOSE_SIG int fd #define LIBC_CLOSE_ARGS fd

+/* fclose(3) */ +#include <stdio.h> + +#define LIBC_FCLOSE_NAME fclose +#define LIBC_FCLOSE_NAME_STR XSTR(LIBC_FCLOSE_NAME) +#define LIBC_FCLOSE_RET_TYPE int +#define LIBC_FCLOSE_SIG FILE *fp +#define LIBC_FCLOSE_ARGS fp + /* gethostbyname(3) - DEPRECATED in glibc. */ #include <netdb.h>

@@ -297,6 +306,12 @@ TSOCKS_DECL(close, LIBC_CLOSE_RET_TYPE, LIBC_CLOSE_SIG) #define LIBC_CLOSE_DECL \ LIBC_CLOSE_RET_TYPE LIBC_CLOSE_NAME(LIBC_CLOSE_SIG)

+/* fclose(3) */ +extern TSOCKS_LIBC_DECL(fclose, LIBC_FCLOSE_RET_TYPE, LIBC_FCLOSE_SIG) +TSOCKS_DECL(fclose, LIBC_FCLOSE_RET_TYPE, LIBC_FCLOSE_SIG) +#define LIBC_FCLOSE_DECL \ + LIBC_FCLOSE_RET_TYPE LIBC_FCLOSE_NAME(LIBC_FCLOSE_SIG) + /* gethostbyname(3) */ extern TSOCKS_LIBC_DECL(gethostbyname, LIBC_GETHOSTBYNAME_RET_TYPE, LIBC_GETHOSTBYNAME_SIG)