Re: [dpdk-dev] [PATCH v3] net/tap: perform proto field update for tun only

["Wiles, Keith" <keith.wiles@intel.com>]

> On May 22, 2018, at 5:47 AM, Varghese, Vipin <vipin.varghese@intel.com> wrote:
> 
> The TX function is shared between TAP and TUN PMD. Checking TUN-TAP
> type field will ensure the TAP PMD will always have protocol field
> as 0.
> 
> Signed-off-by: Vipin Varghese <vipin.varghese@intel.com>
> Suggested-by: Ferruh Yigit <ferruh.yigit@intel.com>
> ---
> Changes in V3:
> - remove type field from rx struct - Ophir Munk
> - add space for comment in struct - Ophir Munk
> - pass type field into eth_dev_tap_create - Ophir Munk
> - replace with enum value for type - Ophir Munk
> - return as 'not supported' for mac_set - Vipin Varghese
> 
> Changes in V2:
> - updated in comment wording - Keith Wiles
> - remove debug print from tx code - Keith Wiles
> —

Sorry, I did not catch the problem below before :-(

> drivers/net/tap/rte_eth_tap.c | 61 +++++++++++++++++++++++++------------------
> drivers/net/tap/rte_eth_tap.h |  9 +++++++
> 2 files changed, 45 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
> index 01552fa..8d8f67b 100644
> --- a/drivers/net/tap/rte_eth_tap.c
> +++ b/drivers/net/tap/rte_eth_tap.c
> @@ -68,7 +68,6 @@ static const char *valid_arguments[] = {
> static int tap_unit;
> static unsigned int tun_unit;
> 
> -static int tap_type;
> static char tuntap_name[8];
> 
> static volatile uint32_t tap_trigger;	/* Rx trigger */
> @@ -116,7 +115,8 @@ tun_alloc(struct pmd_internals *pmd)
> 	 * Do not set IFF_NO_PI as packet information header will be needed
> 	 * to check if a received packet has been truncated.
> 	 */
> -	ifr.ifr_flags = (tap_type) ? IFF_TAP : IFF_TUN | IFF_POINTOPOINT;
> +	ifr.ifr_flags = (pmd->type == ETH_TUNTAP_TYPE_TAP) ?
> +		IFF_TAP : IFF_TUN | IFF_POINTOPOINT;
> 	snprintf(ifr.ifr_name, IFNAMSIZ, "%s", pmd->name);
> 
> 	TAP_LOG(DEBUG, "ifr_name '%s'", ifr.ifr_name);
> @@ -472,20 +472,22 @@ pmd_tx_burst(void *queue, struct rte_mbuf **bufs, uint16_t nb_pkts)
> 		if (rte_pktmbuf_pkt_len(mbuf) > max_size)
> 			break;
> 
> -		/*
> -		 * TUN and TAP are created with IFF_NO_PI disabled.
> -		 * For TUN PMD this mandatory as fields are used by
> -		 * Kernel tun.c to determine whether its IP or non IP
> -		 * packets.
> -		 *
> -		 * The logic fetches the first byte of data from mbuf.
> -		 * compares whether its v4 or v6. If none matches default
> -		 * value 0x00 is taken for protocol field.
> -		 */
> -		char *buff_data = rte_pktmbuf_mtod(seg, void *);
> -		j = (*buff_data & 0xf0);
> -		pi.proto = (j == 0x40) ? 0x0008 :
> +		if (txq->type == ETH_TUNTAP_TYPE_TUN) {
> +			/*
> +			 * TUN and TAP are created with IFF_NO_PI disabled.
> +			 * For TUN PMD this mandatory as fields are used by
> +			 * Kernel tun.c to determine whether its IP or non IP
> +			 * packets.
> +			 *
> +			 * The logic fetches the first byte of data from mbuf
> +			 * then compares whether its v4 or v6. If first byte
> +			 * is 4 or 6, then protocol field is updated.
> +			 */
> +			char *buff_data = rte_pktmbuf_mtod(seg, void *);
> +			j = (*buff_data & 0xf0);
> +			pi.proto = (j == 0x40) ? 0x0008 :
> 				(j == 0x60) ? 0xdd86 : 0x00;

Warning Will Robinson: Magic numbers :-)

Can we use the correct values here ETHERTYPE_IPV6 and ETHERTYPE_IP and then use htons() on the values please.

> +		}
> 
> 		iovecs[0].iov_base = &pi;
> 		iovecs[0].iov_len = sizeof(pi);
> @@ -928,6 +930,9 @@ tap_mac_set(struct rte_eth_dev *dev, struct ether_addr *mac_addr)
> 	struct ifreq ifr;
> 	int ret;
> 
> +	if (pmd->type == ETH_TUNTAP_TYPE_TUN)
> +		return -ENOTSUP;
> +
> 	if (is_zero_ether_addr(mac_addr)) {
> 		TAP_LOG(ERR, "%s: can't set an empty MAC address",
> 			dev->device->name);
> @@ -1025,6 +1030,8 @@ tap_setup_queue(struct rte_eth_dev *dev,
> 	tx->mtu = &dev->data->mtu;
> 	rx->rxmode = &dev->data->dev_conf.rxmode;
> 
> +	tx->type = pmd->type;
> +
> 	return *fd;
> }
> 
> @@ -1342,7 +1349,8 @@ static const struct eth_dev_ops ops = {
> 
> static int
> eth_dev_tap_create(struct rte_vdev_device *vdev, char *tap_name,
> -		   char *remote_iface, struct ether_addr *mac_addr)
> +		   char *remote_iface, struct ether_addr *mac_addr,
> +		   enum rte_tuntap_type type)
> {
> 	int numa_node = rte_socket_id();
> 	struct rte_eth_dev *dev;
> @@ -1364,6 +1372,7 @@ eth_dev_tap_create(struct rte_vdev_device *vdev, char *tap_name,
> 	pmd = dev->data->dev_private;
> 	pmd->dev = dev;
> 	snprintf(pmd->name, sizeof(pmd->name), "%s", tap_name);
> +	pmd->type = type;
> 
> 	pmd->ioctl_sock = socket(AF_INET, SOCK_DGRAM, 0);
> 	if (pmd->ioctl_sock == -1) {
> @@ -1400,7 +1409,7 @@ eth_dev_tap_create(struct rte_vdev_device *vdev, char *tap_name,
> 		pmd->txq[i].fd = -1;
> 	}
> 
> -	if (tap_type) {
> +	if (pmd->type == ETH_TUNTAP_TYPE_TAP) {
> 		if (is_zero_ether_addr(mac_addr))
> 			eth_random_addr((uint8_t *)&pmd->eth_addr);
> 		else
> @@ -1423,7 +1432,7 @@ eth_dev_tap_create(struct rte_vdev_device *vdev, char *tap_name,
> 	if (tap_ioctl(pmd, SIOCSIFMTU, &ifr, 1, LOCAL_AND_REMOTE) < 0)
> 		goto error_exit;
> 
> -	if (tap_type) {
> +	if (pmd->type == ETH_TUNTAP_TYPE_TAP) {
> 		memset(&ifr, 0, sizeof(struct ifreq));
> 		ifr.ifr_hwaddr.sa_family = AF_LOCAL;
> 		rte_memcpy(ifr.ifr_hwaddr.sa_data, &pmd->eth_addr,
> @@ -1642,7 +1651,6 @@ rte_pmd_tun_probe(struct rte_vdev_device *dev)
> 	char tun_name[RTE_ETH_NAME_MAX_LEN];
> 	char remote_iface[RTE_ETH_NAME_MAX_LEN];
> 
> -	tap_type = 0;
> 	strcpy(tuntap_name, "TUN");
> 
> 	name = rte_vdev_device_name(dev);
> @@ -1673,7 +1681,8 @@ rte_pmd_tun_probe(struct rte_vdev_device *dev)
> 	TAP_LOG(NOTICE, "Initializing pmd_tun for %s as %s",
> 		name, tun_name);
> 
> -	ret = eth_dev_tap_create(dev, tun_name, remote_iface, 0);
> +	ret = eth_dev_tap_create(dev, tun_name, remote_iface, 0,
> +		ETH_TUNTAP_TYPE_TUN);
> 
> leave:
> 	if (ret == -1) {
> @@ -1700,7 +1709,6 @@ rte_pmd_tap_probe(struct rte_vdev_device *dev)
> 	struct ether_addr user_mac = { .addr_bytes = {0} };
> 	struct rte_eth_dev *eth_dev;
> 
> -	tap_type = 1;
> 	strcpy(tuntap_name, "TAP");
> 
> 	name = rte_vdev_device_name(dev);
> @@ -1762,7 +1770,8 @@ rte_pmd_tap_probe(struct rte_vdev_device *dev)
> 	TAP_LOG(NOTICE, "Initializing pmd_tap for %s as %s",
> 		name, tap_name);
> 
> -	ret = eth_dev_tap_create(dev, tap_name, remote_iface, &user_mac);
> +	ret = eth_dev_tap_create(dev, tap_name, remote_iface, &user_mac,
> +		ETH_TUNTAP_TYPE_TAP);
> 
> leave:
> 	if (ret == -1) {
> @@ -1784,15 +1793,17 @@ rte_pmd_tap_remove(struct rte_vdev_device *dev)
> 	struct pmd_internals *internals;
> 	int i;
> 
> -	TAP_LOG(DEBUG, "Closing TUN/TAP Ethernet device on numa %u",
> -		rte_socket_id());
> -
> 	/* find the ethdev entry */
> 	eth_dev = rte_eth_dev_allocated(rte_vdev_device_name(dev));
> 	if (!eth_dev)
> 		return 0;
> 
> 	internals = eth_dev->data->dev_private;
> +
> +	TAP_LOG(DEBUG, "Closing %s Ethernet device on numa %u",
> +		(internals->type == ETH_TUNTAP_TYPE_TAP) ? "TAP" : "TUN",
> +		rte_socket_id());
> +
> 	if (internals->nlsk_fd) {
> 		tap_flow_flush(eth_dev, NULL);
> 		tap_flow_implicit_flush(internals, NULL);
> diff --git a/drivers/net/tap/rte_eth_tap.h b/drivers/net/tap/rte_eth_tap.h
> index c87a0b8..7b21d0d 100644
> --- a/drivers/net/tap/rte_eth_tap.h
> +++ b/drivers/net/tap/rte_eth_tap.h
> @@ -23,6 +23,13 @@
> #define RTE_PMD_TAP_MAX_QUEUES	1
> #endif
> 
> +enum rte_tuntap_type {
> +	ETH_TUNTAP_TYPE_UNKNOWN,
> +	ETH_TUNTAP_TYPE_TUN,
> +	ETH_TUNTAP_TYPE_TAP,
> +	ETH_TUNTAP_TYPE_MAX,
> +};
> +
> struct pkt_stats {
> 	uint64_t opackets;              /* Number of output packets */
> 	uint64_t ipackets;              /* Number of input packets */
> @@ -48,6 +55,7 @@ struct rx_queue {
> 
> struct tx_queue {
> 	int fd;
> +	int type;                       /* Type field - TUN|TAP */
> 	uint16_t *mtu;                  /* Pointer to MTU from dev_data */
> 	uint16_t csum:1;                /* Enable checksum offloading */
> 	struct pkt_stats stats;         /* Stats for this TX queue */
> @@ -57,6 +65,7 @@ struct pmd_internals {
> 	struct rte_eth_dev *dev;          /* Ethernet device. */
> 	char remote_iface[RTE_ETH_NAME_MAX_LEN]; /* Remote netdevice name */
> 	char name[RTE_ETH_NAME_MAX_LEN];  /* Internal Tap device name */
> +	int type;                         /* Type field - TUN|TAP */
> 	struct ether_addr eth_addr;       /* Mac address of the device port */
> 	struct ifreq remote_initial_flags;   /* Remote netdevice flags on init */
> 	int remote_if_index;              /* remote netdevice IF_INDEX */
> -- 
> 2.7.4
> 

Regards,
Keith