Added a small libcharon wrapper intended to directly host the nm plugin.

For this reason it reclaims the --enable-nm configure option.
2012-05-03 13:38:14 +02:00
parent 94b48e071a
commit 1c7a733e36
4 changed files with 382 additions and 46 deletions
@@ -0,0 +1,20 @@
+ipsec_PROGRAMS = charon-nm
+
+charon_nm_SOURCES = \
+charon-nm.c
+
+INCLUDES = \
+	-I$(top_srcdir)/src/libstrongswan \
+	-I$(top_srcdir)/src/libhydra \
+	-I$(top_srcdir)/src/libcharon
+
+AM_CFLAGS = \
+	-DIPSEC_DIR=\"${ipsecdir}\" \
+	-DIPSEC_PIDDIR=\"${piddir}\" \
+	-DPLUGINS=\""${nm_plugins}\""
+
+charon_nm_LDADD = \
+	$(top_builddir)/src/libstrongswan/libstrongswan.la \
+	$(top_builddir)/src/libhydra/libhydra.la \
+	$(top_builddir)/src/libcharon/libcharon.la \
+	-lm $(PTHREADLIB) $(DLLIB)
@@ -0,0 +1,308 @@
+/*
+ * Copyright (C) 2012 Tobias Brunner
+ * Hochschule fuer Technik Rapperswil
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#include <stdio.h>
+#include <syslog.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <pwd.h>
+#include <grp.h>
+#ifdef HAVE_PRCTL
+#include <sys/prctl.h>
+#endif
+
+#include <hydra.h>
+#include <daemon.h>
+
+#include <library.h>
+#include <utils/backtrace.h>
+#include <threading/thread.h>
+
+/**
+ * Hook in library for debugging messages
+ */
+extern void (*dbg) (debug_t group, level_t level, char *fmt, ...);
+
+/**
+ * Simple logging hook for library logs, using syslog output
+ */
+static void dbg_syslog(debug_t group, level_t level, char *fmt, ...)
+{
+	if (level <= 1)
+	{
+		char buffer[8192], groupstr[4];
+		va_list args;
+
+		va_start(args, fmt);
+		/* write in memory buffer first */
+		vsnprintf(buffer, sizeof(buffer), fmt, args);
+		/* cache group name */
+		snprintf(groupstr, sizeof(groupstr), "%N", debug_names, group);
+		syslog(LOG_DAEMON|LOG_INFO, "00[%s] %s", groupstr, buffer);
+		va_end(args);
+	}
+}
+
+/**
+ * Run the daemon and handle unix signals
+ */
+static void run()
+{
+	sigset_t set;
+
+	/* handle SIGINT and SIGTERM in this handler */
+	sigemptyset(&set);
+	sigaddset(&set, SIGINT);
+	sigaddset(&set, SIGTERM);
+	sigprocmask(SIG_BLOCK, &set, NULL);
+
+	while (TRUE)
+	{
+		int sig;
+		int error;
+
+		error = sigwait(&set, &sig);
+		if (error)
+		{
+			DBG1(DBG_DMN, "error %d while waiting for a signal", error);
+			return;
+		}
+		switch (sig)
+		{
+			case SIGINT:
+			{
+				DBG1(DBG_DMN, "signal of type SIGINT received. Shutting down");
+				charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
+				return;
+			}
+			case SIGTERM:
+			{
+				DBG1(DBG_DMN, "signal of type SIGTERM received. Shutting down");
+				charon->bus->alert(charon->bus, ALERT_SHUTDOWN_SIGNAL, sig);
+				return;
+			}
+			default:
+			{
+				DBG1(DBG_DMN, "unknown signal %d received. Ignored", sig);
+				break;
+			}
+		}
+	}
+}
+
+/**
+ * Handle SIGSEGV/SIGILL signals raised by threads
+ */
+static void segv_handler(int signal)
+{
+	backtrace_t *backtrace;
+
+	DBG1(DBG_DMN, "thread %u received %d", thread_current_id(), signal);
+	backtrace = backtrace_create(2);
+	backtrace->log(backtrace, stderr, TRUE);
+	backtrace->destroy(backtrace);
+
+	DBG1(DBG_DMN, "killing ourself, received critical signal");
+	abort();
+}
+
+/**
+ * Initialize logging to syslog
+ */
+static void initialize_logger()
+{
+	sys_logger_t *sys_logger;
+	debug_t group;
+	level_t def;
+
+	sys_logger = sys_logger_create(LOG_DAEMON, FALSE);
+	def = lib->settings->get_int(lib->settings,
+								 "charon-nm.syslog.default", 1);
+	for (group = 0; group < DBG_MAX; group++)
+	{
+		sys_logger->set_level(sys_logger, group,
+			lib->settings->get_int(lib->settings, "charon-nm.syslog.%N", def,
+								   debug_lower_names, group));
+	}
+	charon->sys_loggers->insert_last(charon->sys_loggers, sys_logger);
+	charon->bus->add_logger(charon->bus, &sys_logger->logger);
+}
+
+/**
+ * Lookup UID and GID
+ */
+static bool lookup_uid_gid()
+{
+#ifdef IPSEC_USER
+	{
+		char buf[1024];
+		struct passwd passwd, *pwp;
+
+		if (getpwnam_r(IPSEC_USER, &passwd, buf, sizeof(buf), &pwp) != 0 ||
+			pwp == NULL)
+		{
+			DBG1(DBG_DMN, "resolving user '"IPSEC_USER"' failed");
+			return FALSE;
+		}
+		charon->uid = pwp->pw_uid;
+	}
+#endif
+#ifdef IPSEC_GROUP
+	{
+		char buf[1024];
+		struct group group, *grp;
+
+		if (getgrnam_r(IPSEC_GROUP, &group, buf, sizeof(buf), &grp) != 0 ||
+			grp == NULL)
+		{
+			DBG1(DBG_DMN, "resolving group '"IPSEC_GROUP"' failed");
+			return FALSE;
+		}
+		charon->gid = grp->gr_gid;
+	}
+#endif
+	return TRUE;
+}
+
+/**
+ * Drop process capabilities
+ */
+static bool drop_capabilities()
+{
+#ifdef HAVE_PRCTL
+	prctl(PR_SET_KEEPCAPS, 1, 0, 0, 0);
+#endif
+
+	if (setgid(charon->gid) != 0)
+	{
+		DBG1(DBG_DMN, "change to unprivileged group failed");
+		return FALSE;
+	}
+	if (setuid(charon->uid) != 0)
+	{
+		DBG1(DBG_DMN, "change to unprivileged user failed");
+		return FALSE;
+	}
+	if (!charon->drop_capabilities(charon))
+	{
+		DBG1(DBG_DMN, "unable to drop daemon capabilities");
+		return FALSE;
+	}
+	return TRUE;
+}
+
+/**
+ * Main function, starts NetworkManager backend.
+ */
+int main(int argc, char *argv[])
+{
+	struct sigaction action;
+	int status = SS_RC_INITIALIZATION_FAILED;
+
+	/* logging for library during initialization, as we have no bus yet */
+	dbg = dbg_syslog;
+
+	/* initialize library */
+	if (!library_init(NULL))
+	{
+		library_deinit();
+		exit(SS_RC_LIBSTRONGSWAN_INTEGRITY);
+	}
+
+	if (lib->integrity &&
+		!lib->integrity->check_file(lib->integrity, "charon-nm", argv[0]))
+	{
+		dbg_syslog(DBG_DMN, 1, "integrity check of charon-nm failed");
+		library_deinit();
+		exit(SS_RC_DAEMON_INTEGRITY);
+	}
+
+	if (!libhydra_init("charon-nm"))
+	{
+		dbg_syslog(DBG_DMN, 1, "initialization failed - aborting charon-nm");
+		libhydra_deinit();
+		library_deinit();
+		exit(SS_RC_INITIALIZATION_FAILED);
+	}
+
+	if (!libcharon_init())
+	{
+		dbg_syslog(DBG_DMN, 1, "initialization failed - aborting charon-nm");
+		goto deinit;
+	}
+
+	if (!lookup_uid_gid())
+	{
+		dbg_syslog(DBG_DMN, 1, "invalid uid/gid - aborting charon-nm");
+		goto deinit;
+	}
+
+	initialize_logger();
+
+	DBG1(DBG_DMN, "Starting charon NetworkManager backend (strongSwan "VERSION")");
+	if (lib->integrity)
+	{
+		DBG1(DBG_DMN, "integrity tests enabled:");
+		DBG1(DBG_DMN, "lib    'libstrongswan': passed file and segment integrity tests");
+		DBG1(DBG_DMN, "lib    'libhydra': passed file and segment integrity tests");
+		DBG1(DBG_DMN, "lib    'libcharon': passed file and segment integrity tests");
+		DBG1(DBG_DMN, "daemon 'charon-nm': passed file integrity test");
+	}
+
+	/* initialize daemon */
+	if (!charon->initialize(charon,
+			lib->settings->get_str(lib->settings, "charon-nm.load", PLUGINS)))
+	{
+		DBG1(DBG_DMN, "initialization failed - aborting charon-nm");
+		goto deinit;
+	}
+
+	if (!drop_capabilities())
+	{
+		DBG1(DBG_DMN, "capability dropping failed - aborting charon-nm");
+		goto deinit;
+	}
+
+	/* add handler for SEGV and ILL,
+	 * INT and TERM are handled by sigwait() in run() */
+	action.sa_handler = segv_handler;
+	action.sa_flags = 0;
+	sigemptyset(&action.sa_mask);
+	sigaddset(&action.sa_mask, SIGINT);
+	sigaddset(&action.sa_mask, SIGTERM);
+	sigaction(SIGSEGV, &action, NULL);
+	sigaction(SIGILL, &action, NULL);
+	sigaction(SIGBUS, &action, NULL);
+	action.sa_handler = SIG_IGN;
+	sigaction(SIGPIPE, &action, NULL);
+
+	pthread_sigmask(SIG_SETMASK, &action.sa_mask, NULL);
+
+	/* start daemon (i.e. the threads in the thread-pool) */
+	charon->start(charon);
+
+	/* main thread goes to run loop */
+	run();
+
+	status = 0;
+
+deinit:
+	libcharon_deinit();
+	libhydra_deinit();
+	library_deinit();
+	return status;
+}
+