ttl: track ttl value to decrase it or drop pkt if value exceeded

Signed-off-by: hanen mizouni <[email protected]>

include/packetgraph/packetgraph.h

@@ -50,5 +50,6 @@
 #include <packetgraph/tap.h>
 #include <packetgraph/pmtud.h>
 #include <packetgraph/ip-fragment.h>
+#include <packetgraph/ttl.h>
 
 #endif /* _PG_PACKETGRAPH_H */

include/packetgraph/ttl.h

@@ -0,0 +1,38 @@
+/* Copyright 2015 Outscale SAS
+ *
+ * This file is part of Packetgraph.
+ *
+ * Packetgraph is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as published
+ * by the Free Software Foundation.
+ *
+ * Packetgraph 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 Packetgraph.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _PG_TTL_H
+#define _PG_TTL_H
+
+#include <packetgraph/common.h>
+#include <packetgraph/errors.h>
+//#include <rte_mbuf.h>
+
+/**
+ * Create a new ttl brick
+ *
+ * @param   name brick's name
+ * @param   errp is set in case of an error
+ * @return  a pointer to a brick structure on success, NULL on error
+ */
+PG_WARN_UNUSED
+
+struct pg_brick *pg_ttl_new(const char *name, struct pg_error **errp);
+void pg_ttl_handle(struct pg_brick *brick, struct rte_mbuf *pkt,
+		struct pg_error **errp);
+
+#endif  /* _PG_TTL_H */

src/ttl.c

@@ -0,0 +1,112 @@
+/* Copyright 2015 Outscale SAS
+ *
+ * This file is part of Packetgraph.
+ *
+ * Packetgraph is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as published
+ * by the Free Software Foundation.
+ *
+ * Packetgraph 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 Packetgraph.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <packetgraph/packetgraph.h>
+#include "brick-int.h"
+#include "utlis/network.h"
+#include "packets.h"
+#include "utils/mempool.h"
+#include "utils/bitmask.h"
+#include <errno.h>
+#include <rte_mbuf.h>
+
+struct pg_ttl_state {
+	struct pg_brick brick;
+	struct rte_mbuf *pkts[PG_MAX_PKTS_BURST];
+	uint16_t ttl;
+};
+
+static inline void pg_ttl_get_value(struct pg_brick *brick,
+		struct rte_mbuf *pkt, struct pg_error **errp)
+{
+	struct ether_hdr *hdr;
+	uint16_t ttl = pg_brick_get_state(brick, struct pg_ttl_state)->ttl;
+
+	hdr = rte_pktmbuf_mtod(pkt, struct ether_hdr *);
+	switch (rte_cpu_to_be_16(hdr->ethernet.ether_type)) {
+	case ETHER_TYPE_IPv4 :
+		ttl = hdr->ipv4.time_to_live;
+		break;
+	case ETHER_TYPE_IPv6 :
+		ttl = hdr->ipv6.hop_limits;
+		break;
+	default :
+		*errp = pg_error_new("error occured in ethernet.ether_type");
+		return;
+	}
+}
+
+void pg_ttl_handle(struct pg_brick *brick, struct rte_mbuf *pkt,
+			struct pg_error **errp)
+{
+	pg_ttl_get_value(brick, pkt, errp);
+	struct pg_tap_state *state =
+		pg_brick_get_state(brick, struct pg_ttl_state);
+	uint16_t ttl = pg_brick_get_state(brick, struct pg_ttl_state)->ttl;
+
+	if (ttl == 0) {
+	//drop pkt and ICMP msg
+		pg_packets_free(state->pkts, pg_mask_firsts(PG_MAX_PKTS_BURST));
+	} else {
+		ttl--;
+	}
+}
+
+static int ttl_init(struct pg_brick *brick,
+			    struct pg_brick_config *config,
+			    struct pg_error **errp)
+{
+	struct pg_ttl_state *state;
+	struct pg_ttl_config *ttl_config;
+	struct rte_mempool *pool = pg_get_mempool();
+
+	state = pg_brick_get_state(brick, struct pg_ttl_state);
+
+	ttl_config =
+		(struct pg_ttl_config *) config->brick_config;
+
+	/* pre-allocate packets */
+	if (rte_pktmbuf_alloc_bulk(pool, state->pkts,
+				PG_MAX_PKTS_BURST) != 0) {
+		*errp = pg_error_new("packet allocation failed");
+		return -1;
+	}
+	state->ttl = 64;
+
+	return 0;
+}
+struct pg_brick *pg_ttl_new(const char *name, struct pg_error **errp)
+{
+	struct pg_brick_config *config;
+	struct pg_brick *ret;
+
+	config = pg_brick_config_new(name, 1, 1, PG_MONOPOLE);
+	ret = pg_brick_new("ttl", config, errp);
+
+	pg_brick_config_free(config);
+	return ret;
+}
+static struct pg_brick_ops ttl_ops = {
+	.name           = "ttl",
+	.state_size     = sizeof(struct pg_ttl_state),
+
+	.init           = ttl_init,
+
+	.unlink         = pg_brick_generic_unlink,
+};
+
+pg_brick_register(ttl, &ttl_ops);