[dpdk-dev] [PATCH v3] net/pcap: rx_iface_in stream type support

[ido goshen <ido@cgstowernetworks.com>]

From: ido g <ido@cgstowernetworks.com>

Support rx of in direction packets only
Useful for apps that also tx to eth_pcap ports in order to not see them
echoed back in as rx when out direction is also captured

Signed-off-by: ido g <ido@cgstowernetworks.com>
---
v3:
* merge to updated dpdk-next-net code
* pcap_ring doc update

v2:
* clean checkpatch warning

 doc/guides/nics/pcap_ring.rst   | 25 ++++++++++++++++++++++-
 drivers/net/pcap/rte_eth_pcap.c | 45 ++++++++++++++++++++++++++++++++++++++---
 2 files changed, 66 insertions(+), 4 deletions(-)

diff --git a/doc/guides/nics/pcap_ring.rst b/doc/guides/nics/pcap_ring.rst
index 7fd063c..6282be6 100644
--- a/doc/guides/nics/pcap_ring.rst
+++ b/doc/guides/nics/pcap_ring.rst
@@ -71,11 +71,19 @@ The different stream types are:
         tx_pcap=/path/to/file.pcap
 
 *   rx_iface: Defines a reception stream based on a network interface name.
-    The driver reads packets coming from the given interface using the Linux kernel driver for that interface.
+    The driver reads packets from the given interface using the Linux kernel driver for that interface.
+    The driver captures both the incoming and outgoing packets on that interface.
     The value is an interface name.
 
         rx_iface=eth0
 
+*   rx_iface_in: Defines a reception stream based on a network interface name.
+    The driver reads packets from the given interface using the Linux kernel driver for that interface.
+    The driver captures only the incoming packets on that interface.
+    The value is an interface name.
+
+        rx_iface_in=eth0
+
 *   tx_iface: Defines a transmission stream based on a network interface name.
     The driver sends packets to the given interface using the Linux kernel driver for that interface.
     The value is an interface name.
@@ -122,6 +130,21 @@ Forward packets through two network interfaces:
     $RTE_TARGET/app/testpmd -l 0-3 -n 4 \
         --vdev 'net_pcap0,iface=eth0' --vdev='net_pcap1;iface=eth1'
 
+Enable 2 tx queues on a network interface:
+
+.. code-block:: console
+
+    $RTE_TARGET/app/testpmd -l 0-3 -n 4 \
+        --vdev 'net_pcap0,rx_iface=eth1,tx_iface=eth1,tx_iface=eth1' \
+        -- --txq 2
+
+Read only incoming packets from a network interface:
+
+.. code-block:: console
+
+    $RTE_TARGET/app/testpmd -l 0-3 -n 4 \
+        --vdev 'net_pcap0,rx_iface_in=eth1,tx_iface=eth1'
+
 Using libpcap-based PMD with the testpmd Application
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
diff --git a/drivers/net/pcap/rte_eth_pcap.c b/drivers/net/pcap/rte_eth_pcap.c
index b21930b..9c31cef 100644
--- a/drivers/net/pcap/rte_eth_pcap.c
+++ b/drivers/net/pcap/rte_eth_pcap.c
@@ -26,6 +26,7 @@
 #define ETH_PCAP_RX_PCAP_ARG  "rx_pcap"
 #define ETH_PCAP_TX_PCAP_ARG  "tx_pcap"
 #define ETH_PCAP_RX_IFACE_ARG "rx_iface"
+#define ETH_PCAP_RX_IFACE_IN_ARG "rx_iface_in"
 #define ETH_PCAP_TX_IFACE_ARG "tx_iface"
 #define ETH_PCAP_IFACE_ARG    "iface"
 
@@ -83,6 +84,7 @@ struct pmd_devargs {
 	ETH_PCAP_RX_PCAP_ARG,
 	ETH_PCAP_TX_PCAP_ARG,
 	ETH_PCAP_RX_IFACE_ARG,
+	ETH_PCAP_RX_IFACE_IN_ARG,
 	ETH_PCAP_TX_IFACE_ARG,
 	ETH_PCAP_IFACE_ARG,
 	NULL
@@ -739,6 +741,26 @@ struct pmd_devargs {
 }
 
 static inline int
+set_iface_direction(const char *iface,
+		pcap_t *pcap,
+		pcap_direction_t direction)
+{
+	const char *direction_str = (direction == PCAP_D_IN) ? "IN" : "OUT";
+	if (pcap_setdirection(pcap, direction) < 0) {
+		PMD_LOG(ERR,
+				"Setting %s pcap direction %s failed - %s\n",
+				iface,
+				direction_str,
+				pcap_geterr(pcap));
+		return -1;
+	}
+	PMD_LOG(INFO, "Setting %s pcap direction %s\n",
+			iface,
+			direction_str);
+	return 0;
+}
+
+static inline int
 open_iface(const char *key, const char *value, void *extra_args)
 {
 	const char *iface = value;
@@ -761,7 +783,17 @@ struct pmd_devargs {
 static inline int
 open_rx_iface(const char *key, const char *value, void *extra_args)
 {
-	return open_iface(key, value, extra_args);
+	int ret = open_iface(key, value, extra_args);
+	if (ret < 0)
+		return ret;
+	if (strcmp(key, ETH_PCAP_RX_IFACE_IN_ARG) == 0) {
+		struct pmd_devargs *pmd = extra_args;
+		unsigned int qid = pmd->num_of_queue - 1;
+		set_iface_direction(pmd->queue[qid].name,
+				pmd->queue[qid].pcap,
+				PCAP_D_IN);
+	}
+	return 0;
 }
 
 /*
@@ -964,12 +996,18 @@ struct pmd_devargs {
 	is_rx_pcap = rte_kvargs_count(kvlist, ETH_PCAP_RX_PCAP_ARG) ? 1 : 0;
 	pcaps.num_of_queue = 0;
 
-	if (is_rx_pcap)
+	if (is_rx_pcap) {
 		ret = rte_kvargs_process(kvlist, ETH_PCAP_RX_PCAP_ARG,
 				&open_rx_pcap, &pcaps);
-	else
+	} else {
 		ret = rte_kvargs_process(kvlist, ETH_PCAP_RX_IFACE_ARG,
 				&open_rx_iface, &pcaps);
+		if (ret == 0)
+			ret = rte_kvargs_process(kvlist,
+					ETH_PCAP_RX_IFACE_IN_ARG,
+					&open_rx_iface,
+					&pcaps);
+	}
 
 	if (ret < 0)
 		goto free_kvlist;
@@ -1035,6 +1073,7 @@ struct pmd_devargs {
 	ETH_PCAP_RX_PCAP_ARG "=<string> "
 	ETH_PCAP_TX_PCAP_ARG "=<string> "
 	ETH_PCAP_RX_IFACE_ARG "=<ifc> "
+	ETH_PCAP_RX_IFACE_IN_ARG "=<ifc> "
 	ETH_PCAP_TX_IFACE_ARG "=<ifc> "
 	ETH_PCAP_IFACE_ARG "=<ifc>");
 
-- 
1.9.1