pcap-dbus code from Jakub Zawadzki

1 files changed, 271 insertions, 0 deletions

diff --git a/pcap-dbus.c b/pcap-dbus.c
new file mode 100644
index 00000000..dd858437
--- /dev/null
+++ b/pcap-dbus.c
@@ -0,0 +1,271 @@
+/*
+ * Copyright (c) 2012 Jakub Zawadzki
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. The name of the author may not 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.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "pcap-int.h"
+
+#include <string.h>
+
+#include <time.h>
+#include <sys/time.h>
+
+#include <dbus/dbus.h>
+
+static int
+dbus_read(pcap_t *handle, int max_packets, pcap_handler callback, u_char *user)
+{
+	DBusConnection *conn = handle->md.priv;
+
+	struct pcap_pkthdr pkth;
+	DBusMessage *message;
+
+	char *raw_msg;
+	int raw_msg_len;
+
+	int count = 0;
+
+	message = dbus_connection_pop_message(conn);
+
+	while (!message) {
+		// XXX p->md.timeout = timeout_ms;
+		if (!dbus_connection_read_write(conn, 100)) {
+			snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Connection closed");
+			return -1;
+		}
+
+		if (handle->break_loop) {
+			handle->break_loop = 0;
+			return -2;
+		}
+
+		message = dbus_connection_pop_message(conn);
+	}
+
+	if (dbus_message_is_signal(message, DBUS_INTERFACE_LOCAL, "Disconnected")) {
+		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Disconnected");
+		return -1;
+	}
+
+	if (dbus_message_marshal(message, &raw_msg, &raw_msg_len)) {
+		pkth.caplen = pkth.len = raw_msg_len;
+		/* pkth.caplen = min (payload_len, handle->snapshot); */
+
+		gettimeofday(&pkth.ts, NULL);
+		if (handle->fcode.bf_insns == NULL || bpf_filter(handle->fcode.bf_insns, raw_msg, pkth.len, pkth.caplen)) {
+			handle->md.packets_read++;
+			callback(user, &pkth, raw_msg);
+			count++;
+		}
+
+		dbus_free(raw_msg);
+	}
+	return count;
+}
+
+static int
+dbus_write(pcap_t *handle, const void *buf, size_t size)
+{
+	/* XXX, not tested */
+	DBusConnection *conn = handle->md.priv;
+
+	DBusError error = DBUS_ERROR_INIT;
+	DBusMessage *msg;
+
+	if (!(msg = dbus_message_demarshal(buf, size, &error))) {
+		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "dbus_message_demarshal() failed: %s", error.message);
+		dbus_error_free(&error);
+		return -1;
+	}
+
+	dbus_connection_send(conn, msg, NULL);
+	dbus_connection_flush(conn);
+
+	dbus_message_unref(msg);
+	return 0;
+}                           
+
+static int
+dbus_stats(pcap_t *handle, struct pcap_stat *stats)
+{
+	stats->ps_recv = handle->md.packets_read;
+	stats->ps_drop = 0;
+	stats->ps_ifdrop = 0;
+	return 0;
+}
+
+static void
+dbus_cleanup(pcap_t *handle)
+{
+	DBusConnection *conn = handle->md.priv;
+
+	handle->md.priv = NULL;
+	dbus_connection_unref(conn);
+
+	pcap_live_cleanup_common(handle);
+}
+
+static int
+dbus_activate(pcap_t *handle)
+{
+#define EAVESDROPPING_RULE "eavesdrop=true,"
+
+	static const char *rules[] = {
+		EAVESDROPPING_RULE "type='signal'",
+		EAVESDROPPING_RULE "type='method_call'",
+		EAVESDROPPING_RULE "type='method_return'",
+		EAVESDROPPING_RULE "type='error'",
+	};
+
+	#define N_RULES sizeof(rules)/sizeof(rules[0])
+
+	const char *dev = handle->opt.source;
+
+	DBusError error = DBUS_ERROR_INIT;
+	DBusConnection *conn;
+	int i;
+
+	if (strcmp(dev, "dbus-system") == 0) {
+		if (!(conn = dbus_bus_get(DBUS_BUS_SYSTEM, &error))) {
+			snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to get system bus: %s", error.message);
+			dbus_error_free(&error);
+			return PCAP_ERROR;
+		}
+
+	} else if (strcmp(dev, "dbus-session") == 0) {
+		if (!(conn = dbus_bus_get(DBUS_BUS_SESSION, &error))) {
+			snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to get session bus: %s", error.message);
+			dbus_error_free(&error);
+			return PCAP_ERROR;
+		}
+
+	} else if (strncmp(dev, "dbus://", 7) == 0) {
+		const char *addr = dev + 7;
+
+		if (!(conn = dbus_connection_open(addr, &error))) {
+			snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to open connection to: %s: %s", addr, error.message);
+			dbus_error_free(&error);
+			return PCAP_ERROR;
+		}
+
+		if (!dbus_bus_register(conn, &error)) {
+			snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to register bus %s: %s\n", addr, error.message);
+			dbus_error_free(&error);
+			return PCAP_ERROR;
+		}
+
+	} else {
+		snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Can't get bus address from %s", handle->opt.source);
+		return PCAP_ERROR;
+	}
+
+	/* Initialize some components of the pcap structure. */
+	handle->bufsize = 0;
+	handle->offset = 0;
+	handle->linktype = DLT_DBUS;
+	handle->read_op = dbus_read;
+	handle->inject_op = dbus_write;
+	handle->setfilter_op = install_bpf_program; /* XXX, later add support for dbus_bus_add_match() */
+	handle->setdirection_op = NULL;
+	handle->set_datalink_op = NULL;      /* can't change data link type */
+	handle->getnonblock_op = pcap_getnonblock_fd;
+	handle->setnonblock_op = pcap_setnonblock_fd;
+	handle->stats_op = dbus_stats;
+
+	handle->selectable_fd = handle->fd = -1;
+	handle->md.priv = conn;
+
+	if (handle->opt.rfmon) {
+		/*
+		 * Monitor mode doesn't apply to dbus connections.
+		 */
+		dbus_cleanup(handle);
+		return PCAP_ERROR_RFMON_NOTSUP;
+	}
+
+	/* dbus_connection_set_max_message_size(conn, handle->snapshot); */
+	if (handle->opt.buffer_size != 0)
+		dbus_connection_set_max_received_size(conn, handle->opt.buffer_size);
+
+	for (i = 0; i < N_RULES; i++) {
+		dbus_bus_add_match(conn, rules[i], &error);
+		if (dbus_error_is_set(&error)) {
+			dbus_error_free(&error);
+
+			/* try without eavesdrop */
+			dbus_bus_add_match(conn, rules[i] + strlen(EAVESDROPPING_RULE), &error);
+			if (dbus_error_is_set(&error)) {
+				snprintf(handle->errbuf, PCAP_ERRBUF_SIZE, "Failed to add bus match: %s\n", error.message);
+				dbus_error_free(&error);
+				dbus_cleanup(handle);
+				return PCAP_ERROR;
+			}
+		}
+	}
+
+	return 0;
+}
+
+pcap_t *
+dbus_create(const char *device, char *ebuf, int *is_ours)
+{
+	pcap_t *p;
+
+	if (strcmp(device, "dbus-system") && 
+		strcmp(device, "dbus-session") && 
+		strncmp(device, "dbus://", 7))
+	{
+		*is_ours = 0;
+		return NULL;
+	}
+
+	*is_ours = 1;
+	p = pcap_create_common(device, ebuf);
+	if (p == NULL)
+		return (NULL);
+
+	p->activate_op = dbus_activate;
+	return (p);
+}
+
+int 
+dbus_findalldevs(pcap_if_t **alldevsp, char *err_str)
+{
+	pcap_if_t *found_dev = *alldevsp;
+
+	if (pcap_add_if(&found_dev, "dbus-system", 0, "D-BUS system bus", err_str) < 0)
+		return -1;
+	if (pcap_add_if(&found_dev, "dbus-session", 0, "D-BUS session bus", err_str) < 0)
+		return -1;
+	return 0;
+}
+