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From: Antonio Quartulli <ordex@autistici.org>
To: b.a.t.m.a.n@lists.open-mesh.org
Subject: [B.A.T.M.A.N.] [PATCHv5 9/9] batman-adv: Distributed ARP Table - use unicast_4addr_packet for DHT messages
Date: Fri, 10 Feb 2012 00:41:42 +0100	[thread overview]
Message-ID: <1328830902-11574-10-git-send-email-ordex@autistici.org> (raw)
In-Reply-To: <1328830902-11574-1-git-send-email-ordex@autistici.org>

In order to enable an higher verbosity level of the DAT debug messages, the
unicast_4addr_packet is now used to carry ARP packets generated by the DAT
internal mechanism. This packet type will enable batman-adv to recognise each
DAT related message and to print its source (this will help to track possibly
bogus ARP entries)

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
---
 distributed-arp-table.c |  129 +++++++++++++++++++++++++++++++---------------
 distributed-arp-table.h |   16 +++---
 soft-interface.c        |   15 +++--
 3 files changed, 105 insertions(+), 55 deletions(-)

diff --git a/distributed-arp-table.c b/distributed-arp-table.c
index 48e97e0..239b5c4 100644
--- a/distributed-arp-table.c
+++ b/distributed-arp-table.c
@@ -31,6 +31,7 @@
 #include "originator.h"
 #include "send.h"
 #include "soft-interface.h"
+#include "translation-table.h"
 #include "types.h"
 #include "translation-table.h"
 #include "unicast.h"
@@ -38,10 +39,44 @@
 #ifdef CONFIG_BATMAN_ADV_DEBUG
 
 static inline void bat_dbg_arp(struct bat_priv *bat_priv,
-			       struct sk_buff *skb, uint16_t type) {
+			       struct sk_buff *skb, uint16_t type,
+			       int hdr_size) {
+	struct unicast_4addr_packet *unicast_4addr_packet;
+
 	bat_dbg(DBG_ARP, bat_priv, "ARP MSG = [src: %pM-%pI4 dst: %pM-%pI4]\n",
-		ARP_HW_SRC(skb), &ARP_IP_SRC(skb), ARP_HW_DST(skb),
-		&ARP_IP_DST(skb));
+		ARP_HW_SRC(skb, hdr_size), &ARP_IP_SRC(skb, hdr_size),
+		ARP_HW_DST(skb, hdr_size), &ARP_IP_DST(skb, hdr_size));
+
+	if (hdr_size == 0)
+		return;
+
+	/* if the AP packet is encapsulated in a batman packet, let's print some
+	 * debug messages */
+	unicast_4addr_packet = (struct unicast_4addr_packet *)skb->data;
+
+	switch (unicast_4addr_packet->u.header.packet_type) {
+	case BAT_UNICAST:
+		bat_dbg(DBG_ARP, bat_priv, "encapsulated within a UNICAST "
+			"packet\n");
+		break;
+	case BAT_UNICAST_4ADDR:
+		bat_dbg(DBG_ARP, bat_priv, "encapsulated within a "
+			"UNICAST_4ADDR packet (src: %pM)\n",
+			unicast_4addr_packet->src);
+		if (unicast_4addr_packet->subtype != BAT_P_DHT_PUT ||
+		    unicast_4addr_packet->subtype != BAT_P_DHT_GET)
+			bat_dbg(DBG_ARP, bat_priv, "It's a DAT message\n");
+		break;
+	case BAT_BCAST:
+		bat_dbg(DBG_ARP, bat_priv, "encapsulated within a BCAST packet "
+			"(src: %pM)\n",
+			((struct bcast_packet *)unicast_4addr_packet)->orig);
+		break;
+	default:
+		bat_dbg(DBG_ARP, bat_priv, "encapsulated within an unknown "
+			"packet type (0x%x)\n",
+			unicast_4addr_packet->u.header.packet_type);
+	}
 }
 
 #else
@@ -184,7 +219,8 @@ static bool dht_send_data(struct bat_priv *bat_priv, struct sk_buff *skb,
 			goto free_orig;
 
 		tmp_skb = pskb_copy(skb, GFP_ATOMIC);
-		if (prepare_unicast_packet(tmp_skb, cand[i].orig_node))
+		if (prepare_unicast_4addr_packet(bat_priv, tmp_skb,
+						 cand[i].orig_node))
 			send_skb_packet(tmp_skb, neigh_node->if_incoming,
 					neigh_node->addr);
 		else
@@ -228,24 +264,28 @@ out:
 
 /* Returns arphdr->ar_op if the skb contains a valid ARP packet, otherwise
  * returns 0 */
-static uint16_t arp_get_type(struct bat_priv *bat_priv, struct sk_buff *skb)
+static uint16_t arp_get_type(struct bat_priv *bat_priv, struct sk_buff *skb,
+			     int hdr_size)
 {
 	struct arphdr *arphdr;
 	struct ethhdr *ethhdr;
 	uint16_t type = 0;
 
-	if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
+	/* pull the ethernet header */
+	if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN)))
 		goto out;
 
-	ethhdr = (struct ethhdr *)skb_mac_header(skb);
+	ethhdr = (struct ethhdr *)(skb->data + hdr_size);
 
 	if (ethhdr->h_proto != htons(ETH_P_ARP))
 		goto out;
 
-	if (unlikely(!pskb_may_pull(skb, ETH_HLEN + arp_hdr_len(skb->dev))))
+	/* pull the ARP payload */
+	if (unlikely(!pskb_may_pull(skb, hdr_size + ETH_HLEN +
+				    arp_hdr_len(skb->dev))))
 		goto out;
 
-	arphdr = (struct arphdr *)(skb->data + sizeof(struct ethhdr));
+	arphdr = (struct arphdr *)(skb->data + hdr_size + ETH_HLEN);
 
 	/* Check whether the ARP packet carries a valid
 	 * IP information */
@@ -263,10 +303,10 @@ static uint16_t arp_get_type(struct bat_priv *bat_priv, struct sk_buff *skb)
 
 	/* Check for bad reply/request. If the ARP message is not sane, DAT
 	 * will simply ignore it */
-	if (ipv4_is_loopback(ARP_IP_SRC(skb)) ||
-	    ipv4_is_multicast(ARP_IP_SRC(skb)) ||
-	    ipv4_is_loopback(ARP_IP_DST(skb)) ||
-	    ipv4_is_multicast(ARP_IP_DST(skb)))
+	if (ipv4_is_loopback(ARP_IP_SRC(skb, hdr_size)) ||
+	    ipv4_is_multicast(ARP_IP_SRC(skb, hdr_size)) ||
+	    ipv4_is_loopback(ARP_IP_DST(skb, hdr_size)) ||
+	    ipv4_is_multicast(ARP_IP_DST(skb, hdr_size)))
 		goto out;
 
 	type = ntohs(arphdr->ar_op);
@@ -288,18 +328,18 @@ bool dat_snoop_outgoing_arp_request(struct bat_priv *bat_priv,
 	struct hard_iface *primary_if = NULL;
 	struct sk_buff *skb_new;
 
-	type = arp_get_type(bat_priv, skb);
+	type = arp_get_type(bat_priv, skb, 0);
 	/* If we get an ARP_REQUEST we have to send the unicast message to the
 	 * selected DHT candidates */
 	if (type != ARPOP_REQUEST)
 		goto out;
 
 	bat_dbg(DBG_ARP, bat_priv, "Parsing outgoing ARP REQUEST\n");
-	bat_dbg_arp(bat_priv, skb, type);
+	bat_dbg_arp(bat_priv, skb, type, 0);
 
-	ip_src = ARP_IP_SRC(skb);
-	hw_src = ARP_HW_SRC(skb);
-	ip_dst = ARP_IP_DST(skb);
+	ip_src = ARP_IP_SRC(skb, 0);
+	hw_src = ARP_HW_SRC(skb, 0);
+	ip_dst = ARP_IP_DST(skb, 0);
 
 	primary_if = primary_if_get_selected(bat_priv);
 	if (!primary_if)
@@ -341,7 +381,7 @@ out:
  * into the local table. If found, an ARP reply is sent immediately, otherwise
  * the caller has to deliver the ARP request to the upper layer */
 bool dat_snoop_incoming_arp_request(struct bat_priv *bat_priv,
-				    struct sk_buff *skb)
+				    struct sk_buff *skb, int hdr_size)
 {
 	uint16_t type;
 	uint32_t ip_src, ip_dst;
@@ -351,16 +391,16 @@ bool dat_snoop_incoming_arp_request(struct bat_priv *bat_priv,
 	struct neighbour *n = NULL;
 	bool ret = false;
 
-	type = arp_get_type(bat_priv, skb);
+	type = arp_get_type(bat_priv, skb, hdr_size);
 	if (type != ARPOP_REQUEST)
 		goto out;
 
-	hw_src = ARP_HW_SRC(skb);
-	ip_src = ARP_IP_SRC(skb);
-	ip_dst = ARP_IP_DST(skb);
+	hw_src = ARP_HW_SRC(skb, hdr_size);
+	ip_src = ARP_IP_SRC(skb, hdr_size);
+	ip_dst = ARP_IP_DST(skb, hdr_size);
 
 	bat_dbg(DBG_ARP, bat_priv, "Parsing incoming ARP REQUEST\n");
-	bat_dbg_arp(bat_priv, skb, type);
+	bat_dbg_arp(bat_priv, skb, type, hdr_size);
 
 	primary_if = primary_if_get_selected(bat_priv);
 	if (!primary_if)
@@ -380,7 +420,7 @@ bool dat_snoop_incoming_arp_request(struct bat_priv *bat_priv,
 	if (!skb_new)
 		goto out;
 
-	unicast_send_skb(skb_new, bat_priv);
+	unicast_4addr_send_skb(skb_new, bat_priv);
 
 	ret = true;
 out:
@@ -404,17 +444,17 @@ bool dat_snoop_outgoing_arp_reply(struct bat_priv *bat_priv,
 	uint8_t *hw_src, *hw_dst;
 	bool ret = false;
 
-	type = arp_get_type(bat_priv, skb);
+	type = arp_get_type(bat_priv, skb, 0);
 	if (type != ARPOP_REPLY)
 		goto out;
 
 	bat_dbg(DBG_ARP, bat_priv, "Parsing outgoing ARP REPLY\n");
-	bat_dbg_arp(bat_priv, skb, type);
+	bat_dbg_arp(bat_priv, skb, type, 0);
 
-	hw_src = ARP_HW_SRC(skb);
-	ip_src = ARP_IP_SRC(skb);
-	hw_dst = ARP_HW_DST(skb);
-	ip_dst = ARP_IP_DST(skb);
+	hw_src = ARP_HW_SRC(skb, 0);
+	ip_src = ARP_IP_SRC(skb, 0);
+	hw_dst = ARP_HW_DST(skb, 0);
+	ip_dst = ARP_IP_DST(skb, 0);
 
 	arp_neigh_update(bat_priv, ip_src, hw_src);
 	arp_neigh_update(bat_priv, ip_dst, hw_dst);
@@ -431,24 +471,24 @@ out:
 /* This function has to be invoked on an ARP reply coming into the soft
  * interface from the mesh network. The local table has to be updated */
 bool dat_snoop_incoming_arp_reply(struct bat_priv *bat_priv,
-				  struct sk_buff *skb)
+				  struct sk_buff *skb, int hdr_size)
 {
 	uint16_t type;
 	uint32_t ip_src, ip_dst;
 	uint8_t *hw_src, *hw_dst;
 	bool ret = false;
 
-	type = arp_get_type(bat_priv, skb);
+	type = arp_get_type(bat_priv, skb, hdr_size);
 	if (type != ARPOP_REPLY)
 		goto out;
 
 	bat_dbg(DBG_ARP, bat_priv, "Parsing incoming ARP REPLY\n");
-	bat_dbg_arp(bat_priv, skb, type);
+	bat_dbg_arp(bat_priv, skb, type, hdr_size);
 
-	hw_src = ARP_HW_SRC(skb);
-	ip_src = ARP_IP_SRC(skb);
-	hw_dst = ARP_HW_DST(skb);
-	ip_dst = ARP_IP_DST(skb);
+	hw_src = ARP_HW_SRC(skb, hdr_size);
+	ip_src = ARP_IP_SRC(skb, hdr_size);
+	hw_dst = ARP_HW_DST(skb, hdr_size);
+	ip_dst = ARP_IP_DST(skb, hdr_size);
 
 	/* Update our internal cache with both the IP addresses we fetched from
 	 * the ARP reply */
@@ -471,20 +511,25 @@ bool arp_drop_broadcast_packet(struct bat_priv *bat_priv,
 	/* If this packet is an ARP_REQUEST and we already have the information
 	 * that it is going to ask, we can drop the packet */
 	if (!forw_packet->num_packets &&
-			(arp_get_type(bat_priv, forw_packet->skb) ==
+			(arp_get_type(bat_priv, forw_packet->skb,
+				      sizeof(struct bcast_packet)) ==
 							ARPOP_REQUEST)) {
-		n = neigh_lookup(&arp_tbl, &ARP_IP_DST(forw_packet->skb),
+		n = neigh_lookup(&arp_tbl,
+				 &ARP_IP_DST(forw_packet->skb,
+					     sizeof(struct bcast_packet)),
 				 forw_packet->if_incoming->soft_iface);
 		/* check if we already know this neigh */
 		if (n && (n->nud_state & NUD_CONNECTED)) {
 			bat_dbg(DBG_ARP, bat_priv, "ARP Request for %pI4: "
 				"fallback prevented\n",
-				&ARP_IP_DST(forw_packet->skb));
+				&ARP_IP_DST(forw_packet->skb,
+					    sizeof(struct bcast_packet)));
 			return true;
 		}
 
 		bat_dbg(DBG_ARP, bat_priv, "ARP Request for %pI4: fallback\n",
-			&ARP_IP_DST(forw_packet->skb));
+			&ARP_IP_DST(forw_packet->skb,
+				    sizeof(struct bcast_packet)));
 	}
 	return false;
 }
diff --git a/distributed-arp-table.h b/distributed-arp-table.h
index 98fc2e1..a81b021 100644
--- a/distributed-arp-table.h
+++ b/distributed-arp-table.h
@@ -41,20 +41,22 @@ struct forw_packet;
 #define dat_addr_t uint16_t
 #define DAT_ADDR_MAX biggest_unsigned_int(dat_addr_t)
 
-#define ARP_HW_SRC(skb) ((uint8_t *)(skb->data) + sizeof(struct ethhdr) + \
-		sizeof(struct arphdr))
-#define ARP_IP_SRC(skb) (*(uint32_t *)(ARP_HW_SRC(skb) + ETH_ALEN))
-#define ARP_HW_DST(skb) (ARP_HW_SRC(skb) + ETH_ALEN + 4)
-#define ARP_IP_DST(skb) (*(uint32_t *)(ARP_HW_SRC(skb) + ETH_ALEN * 2 + 4))
+#define ARP_HW_SRC(skb, hdr_size) ((uint8_t *)(skb->data + hdr_size) + \
+				sizeof(struct ethhdr) +	sizeof(struct arphdr))
+#define ARP_IP_SRC(skb, hdr_size) (*(uint32_t *)(ARP_HW_SRC(skb, hdr_size) + \
+				ETH_ALEN))
+#define ARP_HW_DST(skb, hdr_size) (ARP_HW_SRC(skb, hdr_size) + ETH_ALEN + 4)
+#define ARP_IP_DST(skb, hdr_size) (*(uint32_t *)(ARP_HW_SRC(skb, hdr_size) + \
+				ETH_ALEN * 2 + 4))
 
 bool dat_snoop_outgoing_arp_request(struct bat_priv *bat_priv,
 				    struct sk_buff *skb);
 bool dat_snoop_incoming_arp_request(struct bat_priv *bat_priv,
-				    struct sk_buff *skb);
+				    struct sk_buff *skb, int hdr_size);
 bool dat_snoop_outgoing_arp_reply(struct bat_priv *bat_priv,
 				  struct sk_buff *skb);
 bool dat_snoop_incoming_arp_reply(struct bat_priv *bat_priv,
-				  struct sk_buff *skb);
+				  struct sk_buff *skb, int hdr_size);
 bool arp_drop_broadcast_packet(struct bat_priv *bat_priv,
 			       struct forw_packet *forw_packet);
 void arp_change_timeout(struct net_device *soft_iface, const char *name);
diff --git a/soft-interface.c b/soft-interface.c
index 4426e36..b21171b 100644
--- a/soft-interface.c
+++ b/soft-interface.c
@@ -258,6 +258,7 @@ void interface_rx(struct net_device *soft_iface,
 		  int hdr_size)
 {
 	struct bat_priv *bat_priv = netdev_priv(soft_iface);
+	struct unicast_4addr_packet *unicast_4addr_packet;
 	struct ethhdr *ethhdr;
 	struct vlan_ethhdr *vhdr;
 	short vid = -1;
@@ -266,6 +267,14 @@ void interface_rx(struct net_device *soft_iface,
 	if (!pskb_may_pull(skb, hdr_size))
 		goto dropped;
 
+	unicast_4addr_packet = (struct unicast_4addr_packet *)skb->data;
+
+	if (dat_snoop_incoming_arp_request(bat_priv, skb, hdr_size))
+		goto out;
+
+	if (dat_snoop_incoming_arp_reply(bat_priv, skb, hdr_size))
+		goto out;
+
 	skb_pull_rcsum(skb, hdr_size);
 	skb_reset_mac_header(skb);
 
@@ -284,12 +293,6 @@ void interface_rx(struct net_device *soft_iface,
 		goto dropped;
 	}
 
-	if (dat_snoop_incoming_arp_request(bat_priv, skb))
-		goto out;
-
-	if (dat_snoop_incoming_arp_reply(bat_priv, skb))
-		goto out;
-
 	/* skb->dev & skb->pkt_type are set here */
 	if (unlikely(!pskb_may_pull(skb, ETH_HLEN)))
 		goto dropped;
-- 
1.7.3.4


  parent reply	other threads:[~2012-02-09 23:41 UTC|newest]

Thread overview: 27+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-02-09 23:41 [B.A.T.M.A.N.] [PATCHv5 0/9] DAT: Distributed ARP Table Antonio Quartulli
2012-02-09 23:41 ` [B.A.T.M.A.N.] [PATCHv5 1/9] batman-adv: implement an helper function to forge unicast packets Antonio Quartulli
2012-02-09 23:41 ` [B.A.T.M.A.N.] [PATCHv5 2/9] batman-adv: add a new log level for DAT/ARP debugging Antonio Quartulli
2012-02-09 23:41 ` [B.A.T.M.A.N.] [PATCHv5 3/9] batman-adv: Distributed ARP Table - create DHT helper functions Antonio Quartulli
2012-02-11 13:59   ` Marek Lindner
2012-02-13 20:33     ` Antonio Quartulli
2012-02-14  6:07       ` Marek Lindner
2012-02-14  7:47         ` Antonio Quartulli
2012-02-09 23:41 ` [B.A.T.M.A.N.] [PATCHv5 4/9] batman-adv: Distributed ARP Table - add ARP parsing functions Antonio Quartulli
2012-02-10 14:21   ` Marek Lindner
2012-02-11 14:09   ` Marek Lindner
2012-02-14 10:43     ` Antonio Quartulli
2012-02-09 23:41 ` [B.A.T.M.A.N.] [PATCHv5 5/9] batman-adv: Distributed ARP Table - add snooping functions for ARP messages Antonio Quartulli
2012-02-10 14:25   ` Marek Lindner
2012-02-09 23:41 ` [B.A.T.M.A.N.] [PATCHv5 6/9] batman-adv: Distributed ARP Table - increase default soft_iface ARP table timeout Antonio Quartulli
2012-02-09 23:41 ` [B.A.T.M.A.N.] [PATCHv5 7/9] batman-adv: Distributed ARP Table - add compile option Antonio Quartulli
2012-02-10 14:32   ` Marek Lindner
2012-02-15 19:47     ` Antonio Quartulli
2012-02-16  6:35       ` Marek Lindner
2012-02-09 23:41 ` [B.A.T.M.A.N.] [PATCHv5 8/9] batman-adv: add UNICAST_4ADDR packet type Antonio Quartulli
2012-02-10 14:42   ` Marek Lindner
2012-02-12 14:27   ` Marek Lindner
2012-02-09 23:41 ` Antonio Quartulli [this message]
2012-02-11 13:44   ` [B.A.T.M.A.N.] [PATCHv5 9/9] batman-adv: Distributed ARP Table - use unicast_4addr_packet for DHT messages Marek Lindner
2012-02-11 13:57     ` Antonio Quartulli
2012-02-09 23:52 ` [B.A.T.M.A.N.] [PATCHv5 0/9] DAT: Distributed ARP Table Antonio Quartulli
2012-02-10  9:44 ` Marek Lindner

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