Add support for vdev tap devices

This commit adds support for the creation of tap devices.
To create a tap device, and associate it with a DPDK port,
add within the port section:
vdev=<tap_name>
local ipv4=<ip_assigned_to_port>
<tap_name> will appear as a kernel network device, with an IP <ip_assigned_to_port>

ARP packets received from the network on the DPDK interface will be forwarded to the kernel.
1st packet which needs to be generated to a new IP will cause an IP packet
to be sent to the kernel (using socket sendto) forcing the kernel to send an ARP_REQUEST.

In this commit, there is no notification from the kernel about ARP table changes.
This is subject to further commits.

Two config files, gen_tap.cfg and swap_tap.cfg have been created. They work one against each other.
*** Note however that they do not work if running within the same host
(with the port being connected back to back) ***
This is due to the fact that the kernel would bypass the ports and use local interface...

Change-Id: Iadeec0d99e3c693472ea44bdb9163a3bf97df2fa
Signed-off-by: Xavier Simonart <xavier.simonart@intel.com>

1 files changed, 65 insertions, 2 deletions

diff --git a/VNFs/DPPD-PROX/prox_port_cfg.c b/VNFs/DPPD-PROX/prox_port_cfg.c
index 74514062..9798c590 100644
--- a/VNFs/DPPD-PROX/prox_port_cfg.c
+++ b/VNFs/DPPD-PROX/prox_port_cfg.c
@@ -1,5 +1,5 @@
 /*
-// Copyright (c) 2010-2017 Intel Corporation
+// Copyright (c) 2010-2020 Intel Corporation
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -31,6 +31,9 @@
 #endif
 #endif
 
+#include <sys/ioctl.h>
+#include <net/if.h>
+
 #include "prox_port_cfg.h"
 #include "prox_globals.h"
 #include "log.h"
@@ -161,14 +164,70 @@ void prox_pktmbuf_reinit(void *arg, void *start, __attribute__((unused)) void *e
         }\
 
 
+static void set_ip_address (char *devname, uint32_t *ip)
+{
+	struct ifreq ifreq;
+	struct sockaddr_in in_addr;
+	int fd, rc;
+
+	memset(&ifreq, 0, sizeof(struct ifreq));
+	memset(&in_addr, 0, sizeof(struct sockaddr_in));
+
+	in_addr.sin_family = AF_INET;
+	in_addr.sin_addr = *(struct in_addr *)ip;
+	fd = socket(in_addr.sin_family, SOCK_DGRAM, 0);
+
+	strncpy(ifreq.ifr_name, devname, IFNAMSIZ);
+	ifreq.ifr_addr = *(struct sockaddr *)&in_addr;
+	rc = ioctl(fd, SIOCSIFADDR, &ifreq);
+	PROX_PANIC(rc < 0, "Failed to set IP address %d on device %s: error = %d\n", *ip, devname, errno);
+	close(fd);
+}
+
 /* initialize rte devices and check the number of available ports */
 void init_rte_dev(int use_dummy_devices)
 {
 	uint8_t nb_ports, port_id_max;
-	int port_id_last;
+	int port_id_last, rc = 0;
 	struct rte_eth_dev_info dev_info;
 	const struct rte_pci_device *pci_dev;
 
+	for (uint8_t port_id = 0; port_id < PROX_MAX_PORTS; ++port_id) {
+		if (!prox_port_cfg[port_id].active) {
+			continue;
+		}
+		struct prox_port_cfg* port_cfg = &prox_port_cfg[port_id];
+		if (port_cfg->vdev[0]) {
+#if (RTE_VERSION > RTE_VERSION_NUM(17,5,0,1))
+			char name[MAX_NAME_SIZE], tap[MAX_NAME_SIZE];
+			snprintf(tap, MAX_NAME_SIZE, "net_tap%d", port_id);
+			snprintf(name, MAX_NAME_SIZE, "iface=%s", port_cfg->vdev);
+			rc = rte_vdev_init(tap, name);
+#else
+			rc = eth_dev_null_create(tap, name, PROX_RTE_ETHER_MIN_LEN, 0);
+#endif
+			PROX_PANIC(rc != 0, "Unable to create device %s %s\n", "net tap", port_cfg->vdev);
+			int vdev_port_id = rte_eth_dev_count() - 1;
+			PROX_PANIC(vdev_port_id >= PROX_MAX_PORTS, "Too many port defined %d >= %d\n", vdev_port_id, PROX_MAX_PORTS);
+			plog_info("\tCreating device %s, port %d\n", port_cfg->vdev, vdev_port_id);
+			prox_port_cfg[vdev_port_id].active = 1;
+			prox_port_cfg[vdev_port_id].dpdk_mapping = port_id;
+			prox_port_cfg[vdev_port_id].n_txq = 1;
+			strncpy(prox_port_cfg[vdev_port_id].name, port_cfg->vdev, MAX_NAME_SIZE);
+			prox_port_cfg[port_id].dpdk_mapping = vdev_port_id;
+			prox_port_cfg[vdev_port_id].ip = rte_be_to_cpu_32(prox_port_cfg[port_id].ip);
+			prox_port_cfg[port_id].ip = 0;	// So only vdev has an IP associated
+			prox_port_cfg[vdev_port_id].type = prox_port_cfg[port_id].type;
+			if (prox_port_cfg[vdev_port_id].type == PROX_PORT_MAC_HW) {
+				// If DPDK port MAC set to HW, then make sure the vdev has the same MAC as DPDK port
+				prox_port_cfg[vdev_port_id].type = PROX_PORT_MAC_SET;
+				rte_eth_macaddr_get(port_id, &prox_port_cfg[vdev_port_id].eth_addr);
+				plog_info("\tDPDK port %d MAC address pre-configured to MAC from port %d: "MAC_BYTES_FMT"\n",
+					vdev_port_id, port_id, MAC_BYTES(prox_port_cfg[vdev_port_id].eth_addr.addr_bytes));
+			} else
+				memcpy(&prox_port_cfg[vdev_port_id].eth_addr, &prox_port_cfg[port_id].eth_addr, sizeof(prox_port_cfg[port_id].eth_addr));
+		}
+	}
 	nb_ports = prox_rte_eth_dev_count_avail();
 	/* get available ports configuration */
 	PROX_PANIC(use_dummy_devices && nb_ports, "Can't use dummy devices while there are also real ports\n");
@@ -681,6 +740,9 @@ static void init_port(struct prox_port_cfg *port_cfg)
 	PROX_PANIC(ret < 0, "\n\t\t\trte_eth_dev_start() failed on port %u: error %d\n", port_id, ret);
 	plog_info(" done: ");
 
+	if (prox_port_cfg[port_id].ip) {
+		set_ip_address(prox_port_cfg[port_id].name, &prox_port_cfg[port_id].ip);
+	}
 	/* Getting link status can be done without waiting if Link
 	   State Interrupt is enabled since in that case, if the link
 	   is recognized as being down, an interrupt will notify that
@@ -782,6 +844,7 @@ void init_port_addr(void)
 			prox_rte_eth_random_addr(port_cfg->eth_addr.addr_bytes);
 			break;
 		case PROX_PORT_MAC_SET:
+			plog_info("Setting MAC to "MAC_BYTES_FMT"\n", MAC_BYTES(port_cfg->eth_addr.addr_bytes));
 			if ((rc = rte_eth_dev_default_mac_addr_set(port_id, &port_cfg->eth_addr)) != 0)
 				plog_warn("port %u: failed to set mac address. Error = %d\n", port_id, rc);
 			break;