[tor-commits] [torsocks/master] Add torsocks.c/.h with logging initialization

[dgoulet at torproject.org]

commit 7a2244dd3d03767f78d73e4d62d2cf54ca67ff2d
Author: David Goulet <dgoulet at ev0ke.net>
Date:   Mon Jun 3 21:04:22 2013 -0400

    Add torsocks.c/.h with logging initialization
    
    Signed-off-by: David Goulet <dgoulet at ev0ke.net>
---
 src/lib/Makefile.am |    7 +++--
 src/lib/torsocks.c  |   87 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/lib/torsocks.h  |   25 +++++++++++++++
 3 files changed, 116 insertions(+), 3 deletions(-)

diff --git a/src/lib/Makefile.am b/src/lib/Makefile.am
index 4a4fbea..f578d3f 100644
--- a/src/lib/Makefile.am
+++ b/src/lib/Makefile.am
@@ -3,12 +3,13 @@ AM_CPPFLAGS = -I$(top_srcdir)/include -I$(top_srcdir)/src -I$(builddir)
 libdir = @libdir@/torsocks
 
 # Install invocation scripts
-bin_SCRIPTS = torsocks usewithtor
-INSTALL_SCRIPT = $(install_sh) -c -m 755
+#bin_SCRIPTS = torsocks usewithtor
+#INSTALL_SCRIPT = $(install_sh) -c -m 755
+EXTRA_DIST = torsocks.in usewithtor.in
 
 lib_LTLIBRARIES = libtorsocks.la
 
-libtorsocks_la_SOURCES =
+libtorsocks_la_SOURCES = torsocks.c torsocks.h
 
 libtorsocks_la_LDFLAGS = $(TORSOCKSLDFLAGS)
 
diff --git a/src/lib/torsocks.c b/src/lib/torsocks.c
new file mode 100644
index 0000000..c0450ad
--- /dev/null
+++ b/src/lib/torsocks.c
@@ -0,0 +1,87 @@
+/*
+ * Copyright (C) 2000-2008 - Shaun Clowes <delius at progsoc.org> 
+ * 				 2008-2011 - Robert Hogan <robert at roberthogan.net>
+ * 				 	  2013 - David Goulet <dgoulet at 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 <stdlib.h>
+
+#include <common/defaults.h>
+#include <common/log.h>
+
+#include "torsocks.h"
+
+/*
+ * Set to 1 if the binary is set with suid or 0 if not. This is set once during
+ * initialization so after that it can be read without any protection.
+ */
+static int is_suid;
+
+/*
+ * Initialize logging subsytem using either the default values or the one given
+ * by the environment variables.
+ */
+static void init_logging(void)
+{
+	int level;
+	const char *filepath = NULL, *level_str, *time_status_str;
+	enum log_time_status t_status;
+
+	/* Get log level from user or use default. */
+	level_str = getenv(DEFAULT_LOG_LEVEL_ENV);
+	if (level_str) {
+		level = atoi(level_str);
+	} else {
+		/* Set to the default loglevel. */
+		level = tsocks_loglevel;
+	}
+
+	/* Get time status from user or use default. */
+	time_status_str = getenv(DEFAULT_LOG_TIME_ENV);
+	if (time_status_str) {
+		t_status = atoi(time_status_str);
+	} else {
+		t_status = DEFAULT_LOG_TIME_STATUS;
+	}
+
+	/* NULL value is valid which will set the output to stderr. */
+	if (!is_suid) {
+		filepath = getenv(DEFAULT_LOG_FILEPATH_ENV);
+	}
+
+	/*
+	 * The return value is not important because this call will output the
+	 * errors to the user if needed. Worst case, there is no logging.
+	 */
+	(void) log_init(level, filepath, t_status);
+
+	/* After this, it is safe to call any logging macros. */
+
+	DBG("Logging subsytem initialized. Level %d, file %s, time %d",
+			level, filepath, t_status);
+}
+
+/*
+ * Lib constructor. Initialize torsocks here before the main execution of the
+ * binary we are preloading.
+ */
+static void __attribute__((constructor)) init()
+{
+	/* UID and effective UID MUST be the same or else we are SUID. */
+	is_suid = (getuid() != geteuid());
+
+	init_logging();
+}
diff --git a/src/lib/torsocks.h b/src/lib/torsocks.h
new file mode 100644
index 0000000..7e6eec1
--- /dev/null
+++ b/src/lib/torsocks.h
@@ -0,0 +1,25 @@
+/*
+ * Copyright (C) 2000-2008 - Shaun Clowes <delius at progsoc.org> 
+ * 				 2008-2011 - Robert Hogan <robert at roberthogan.net>
+ * 				 	  2013 - David Goulet <dgoulet at 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.
+ */
+
+#ifndef TORSOCKS_H
+#define TORSOCKS_H
+
+#include <common/compat.h>
+
+#endif /* TORSOCKS_H */