[PATCH v2] pcap: support MTU set

[Stephen Hemminger <stephen@networkplumber.org>]

Support rte_eth_dev_set_mtu for pcap driver when the
pcap device is convigured to point to a network interface.

This is rebased an consolidated from earlier version.
Added support for FreeBSD.

Signed-off-by: Ido Goshen <ido@cgstowernetworks.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
v2 - fix FreeBSD part

 drivers/net/pcap/pcap_ethdev.c        | 49 ++++++++++++++++++++++++++-
 drivers/net/pcap/pcap_osdep.h         |  1 +
 drivers/net/pcap/pcap_osdep_freebsd.c | 23 +++++++++++++
 drivers/net/pcap/pcap_osdep_linux.c   | 21 ++++++++++++
 drivers/net/pcap/pcap_osdep_windows.c |  7 ++++
 5 files changed, 100 insertions(+), 1 deletion(-)

diff --git a/drivers/net/pcap/pcap_ethdev.c b/drivers/net/pcap/pcap_ethdev.c
index bfec0850456f..672f42d30d8e 100644
--- a/drivers/net/pcap/pcap_ethdev.c
+++ b/drivers/net/pcap/pcap_ethdev.c
@@ -5,6 +5,7 @@
  */
 
 #include <stdlib.h>
+#include <stdbool.h>
 #include <time.h>
 
 #include <pcap.h>
@@ -495,8 +496,13 @@ eth_pcap_tx(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
 		 */
 		ret = pcap_sendpacket(pcap,
 			rte_pktmbuf_read(mbuf, 0, len, temp_data), len);
-		if (unlikely(ret != 0))
+		if (unlikely(ret != 0)) {
+			/* Oversize packet dropped due to MTU */
+			if (errno == EMSGSIZE)
+				continue;
 			break;
+		}
+
 		num_tx++;
 		tx_bytes += len;
 		rte_pktmbuf_free(mbuf);
@@ -808,6 +814,46 @@ eth_stats_reset(struct rte_eth_dev *dev)
 	return 0;
 }
 
+static int
+eth_mtu_set(struct rte_eth_dev *dev, uint16_t mtu)
+{
+	struct pmd_internals *internals = dev->data->dev_private;
+	unsigned int i;
+	bool is_supported = false;
+	int ret;
+
+	for (i = 0; i < dev->data->nb_rx_queues; i++) {
+		struct pcap_rx_queue *queue = &internals->rx_queue[i];
+
+		if ((strcmp(queue->type, ETH_PCAP_IFACE_ARG) == 0) ||
+		    (strcmp(queue->type, ETH_PCAP_RX_IFACE_ARG) == 0) ||
+		    (strcmp(queue->type, ETH_PCAP_RX_IFACE_IN_ARG) == 0)) {
+			ret = osdep_iface_mtu_set(queue->name, mtu);
+			if (ret < 0)
+				return ret;
+			is_supported = true;
+		}
+	}
+
+	for (i = 0; i < dev->data->nb_tx_queues; i++) {
+		struct pcap_tx_queue *queue = &internals->tx_queue[i];
+
+		if ((strcmp(queue->type, ETH_PCAP_IFACE_ARG) == 0) ||
+		    (strcmp(queue->type, ETH_PCAP_TX_IFACE_ARG) == 0)) {
+			ret = osdep_iface_mtu_set(queue->name, mtu);
+			if (ret < 0)
+				return ret;
+			is_supported = true;
+		}
+	}
+
+	if (!is_supported)
+		return -ENOTSUP;
+
+	PMD_LOG(INFO, "MTU set %s %u\n", dev->device->name, mtu);
+	return 0;
+}
+
 static inline void
 infinite_rx_ring_free(struct rte_ring *pkts)
 {
@@ -1005,6 +1051,7 @@ static const struct eth_dev_ops ops = {
 	.link_update = eth_link_update,
 	.stats_get = eth_stats_get,
 	.stats_reset = eth_stats_reset,
+	.mtu_set = eth_mtu_set,
 };
 
 static int
diff --git a/drivers/net/pcap/pcap_osdep.h b/drivers/net/pcap/pcap_osdep.h
index bf41cba982ec..043677ec777d 100644
--- a/drivers/net/pcap/pcap_osdep.h
+++ b/drivers/net/pcap/pcap_osdep.h
@@ -14,5 +14,6 @@ extern int eth_pcap_logtype;
 
 int osdep_iface_index_get(const char *name);
 int osdep_iface_mac_get(const char *name, struct rte_ether_addr *mac);
+int osdep_iface_mtu_set(const char *name, uint16_t mtu);
 
 #endif
diff --git a/drivers/net/pcap/pcap_osdep_freebsd.c b/drivers/net/pcap/pcap_osdep_freebsd.c
index 20556b3e9215..de6358197391 100644
--- a/drivers/net/pcap/pcap_osdep_freebsd.c
+++ b/drivers/net/pcap/pcap_osdep_freebsd.c
@@ -6,7 +6,9 @@
 
 #include <net/if.h>
 #include <net/if_dl.h>
+#include <sys/ioctl.h>
 #include <sys/sysctl.h>
+#include <unistd.h>
 
 #include <rte_malloc.h>
 #include <rte_memcpy.h>
@@ -57,3 +59,24 @@ osdep_iface_mac_get(const char *if_name, struct rte_ether_addr *mac)
 	rte_free(buf);
 	return 0;
 }
+
+int
+osdep_iface_mtu_set(const char *if_name, uint16_t mtu)
+{
+	struct ifreq ifr = { };
+	int if_fd = socket(AF_INET, SOCK_DGRAM, 0);
+
+	if (if_fd == -1)
+		return -errno;
+
+	strlcpy(ifr.ifr_name, if_name, sizeof(ifr.ifr_name));
+	ifr.ifr_mtu = mtu;
+	if (ioctl(if_fd, SIOCSIFMTU, &ifr)) {
+		PMD_LOG(ERR, "%s mtu set to %d failed\n", if_name, mtu);
+		close(if_fd);
+		return -errno;
+	}
+
+	close(if_fd);
+	return 0;
+}
diff --git a/drivers/net/pcap/pcap_osdep_linux.c b/drivers/net/pcap/pcap_osdep_linux.c
index 97033f57c5d9..845296595f86 100644
--- a/drivers/net/pcap/pcap_osdep_linux.c
+++ b/drivers/net/pcap/pcap_osdep_linux.c
@@ -40,3 +40,24 @@ osdep_iface_mac_get(const char *if_name, struct rte_ether_addr *mac)
 	close(if_fd);
 	return 0;
 }
+
+int
+osdep_iface_mtu_set(const char *if_name, uint16_t mtu)
+{
+	struct ifreq ifr;
+	int if_fd = socket(AF_INET, SOCK_DGRAM, 0);
+
+	if (if_fd == -1)
+		return -errno;
+
+	rte_strscpy(ifr.ifr_name, if_name, sizeof(ifr.ifr_name));
+	ifr.ifr_mtu = mtu;
+	if (ioctl(if_fd, SIOCSIFMTU, &ifr)) {
+		PMD_LOG(ERR, "%s mtu set to %d failed\n", if_name, mtu);
+		close(if_fd);
+		return -errno;
+	}
+
+	close(if_fd);
+	return 0;
+}
diff --git a/drivers/net/pcap/pcap_osdep_windows.c b/drivers/net/pcap/pcap_osdep_windows.c
index 1d398dc7ed9f..db34fc49e22e 100644
--- a/drivers/net/pcap/pcap_osdep_windows.c
+++ b/drivers/net/pcap/pcap_osdep_windows.c
@@ -116,3 +116,10 @@ osdep_iface_mac_get(const char *device_name, struct rte_ether_addr *mac)
 	free(info);
 	return ret;
 }
+
+int
+osdep_iface_mtu_set(__rte_unused const char *device_name, __rte_unused uint16_t mtu)
+{
+	PMD_LOG(ERR, "mtu set not supported on Windows\n");
+	return -ENOTSUP;
+}
-- 
2.39.2