pcap-dpdk.c

/*
 * Copyright (C) 2018 jingle YANG. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   1. Redistributions of source code must retain the above copyright
 *      notice, this list of conditions and the following disclaimer.
 *   2. Redistributions in binary form must reproduce the above copyright
 *      notice, this list of conditions and the following disclaimer in the
 *      documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS''AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
Date: Dec 16, 2018

Description:
1. Pcap-dpdk provides libpcap the ability to use DPDK with the device name as dpdk:{portid}, such as dpdk:0.
2. DPDK is a set of libraries and drivers for fast packet processing. (https://www.dpdk.org/) 
3. The testprogs/capturetest provides 6.4Gbps/800,000 pps on Intel 10-Gigabit X540-AT2 with DPDK 18.11.

Limitations:
1. DPDK support will be on if DPDK is available. Please set DIR for --with-dpdk[=DIR] with ./configure or -DDPDK_DIR[=DIR] with cmake if DPDK is installed manually.
2. Only support link libdpdk.so dynamicly, because the libdpdk.a will not work correctly.
3. Only support read operation, and packet injection has not been supported yet.

Usage:
1. Compile DPDK as shared library and install.(https://github.com/DPDK/dpdk.git)

You shall modify the file $RTE_SDK/$RTE_TARGET/.config and set:
CONFIG_RTE_BUILD_SHARED_LIB=y
By the following command:
sed -i 's/CONFIG_RTE_BUILD_SHARED_LIB=n/CONFIG_RTE_BUILD_SHARED_LIB=y/' $RTE_SDK/$RTE_TARGET/.config

2. Launch l2fwd that is one of DPDK examples correctly, and get device information.

You shall learn how to bind nic with DPDK-compatible driver by $RTE_SDK/usertools/dpdk-devbind.py, such as igb_uio.
And enable hugepages by dpdk-setup.sh

Then launch the l2fwd with dynamic dirver support. For example:
$RTE_SDK/examples/l2fwd/$RTE_TARGET/l2fwd -dlibrte_pmd_e1000.so -dlibrte_pmd_ixgbe.so -dlibrte_mempool_ring.so -- -p 0x1

3. Compile libpcap with dpdk options.

If DPDK has not been found automatically, you shall export DPDK envionment variable which are used for compiling DPDK. And then pass $RTE_SDK/$RTE_TARGET to --with-dpdk or -DDPDK_DIR

export RTE_SDK={your DPDK base directory}
export RTE_TARGET={your target name}

3.1 With configure

./configure --with-dpdk=$RTE_SDK/$RTE_TARGET && make -s all && make -s testprogs && make install

3.2 With cmake

mkdir -p build && cd build && cmake -DDPDK_DIR=$RTE_SDK/$RTE_TARGET ../ && make -s all && make -s testprogs && make install 

4. Link your own program with libpcap, and use DPDK with the device name as dpdk:{portid}, such as dpdk:0.
And you shall set DPDK configure options by environment variable DPDK_CFG
For example, the testprogs/capturetest could be lanched by: 

env DPDK_CFG="--log-level=debug -l0 -dlibrte_pmd_e1000.so -dlibrte_pmd_ixgbe.so -dlibrte_mempool_ring.so" ./capturetest -i dpdk:0
*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <ctype.h>
#include <errno.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <time.h>

#include <sys/time.h>

//header for calling dpdk
#include <rte_common.h>
#include <rte_log.h>
#include <rte_malloc.h>
#include <rte_memory.h>
#include <rte_eal.h>
#include <rte_launch.h>
#include <rte_atomic.h>
#include <rte_cycles.h>
#include <rte_lcore.h>
#include <rte_per_lcore.h>
#include <rte_branch_prediction.h>
#include <rte_interrupts.h>
#include <rte_random.h>
#include <rte_debug.h>
#include <rte_ether.h>
#include <rte_ethdev.h>
#include <rte_mempool.h>
#include <rte_mbuf.h>
#include <rte_bus.h>

#include "pcap-int.h"
#include "pcap-dpdk.h"

#define DPDK_DEF_LOG_LEV RTE_LOG_ERR
static int is_dpdk_pre_inited=0;
#define DPDK_LIB_NAME "libpcap_dpdk"
#define DPDK_DESC "Data Plane Development Kit (DPDK) Interface"
#define DPDK_ERR_PERM_MSG "permission denied, DPDK needs root permission"
#define DPDK_ARGC_MAX 64 
#define DPDK_CFG_MAX_LEN 1024
#define DPDK_DEV_NAME_MAX 32
#define DPDK_DEV_DESC_MAX 512 
#define DPDK_CFG_ENV_NAME "DPDK_CFG"
#define DPDK_DEF_MIN_SLEEP_MS 1
static char dpdk_cfg_buf[DPDK_CFG_MAX_LEN];
#define DPDK_MAC_ADDR_SIZE 32
#define DPDK_DEF_MAC_ADDR "00:00:00:00:00:00"
#define DPDK_PCI_ADDR_SIZE 16
#define DPDK_DEF_CFG "--log-level=error -l0 -dlibrte_pmd_e1000.so -dlibrte_pmd_ixgbe.so -dlibrte_mempool_ring.so"
#define DPDK_PREFIX "dpdk:"
#define DPDK_PORTID_MAX 65535U
#define MBUF_POOL_NAME "mbuf_pool"
#define DPDK_TX_BUF_NAME "tx_buffer"
//The number of elements in the mbuf pool.
#define DPDK_NB_MBUFS 8192U
#define MEMPOOL_CACHE_SIZE 256
#define MAX_PKT_BURST 32 
// Configurable number of RX/TX ring descriptors
#define RTE_TEST_RX_DESC_DEFAULT 1024
#define RTE_TEST_TX_DESC_DEFAULT 1024

static uint16_t nb_rxd = RTE_TEST_RX_DESC_DEFAULT;
static uint16_t nb_txd = RTE_TEST_TX_DESC_DEFAULT;

#define RTE_ETH_PCAP_SNAPLEN ETHER_MAX_JUMBO_FRAME_LEN

static struct rte_eth_dev_tx_buffer *tx_buffer;

struct dpdk_ts_helper{
	struct timeval start_time;
	uint64_t start_cycles;
	uint64_t hz;
};
struct pcap_dpdk{
	pcap_t * orig;
	uint16_t portid; // portid of DPDK
	int must_clear_promisc;
	uint64_t bpf_drop;
	int nonblock;
	struct timeval required_select_timeout;
	struct timeval prev_ts;
	struct rte_eth_stats prev_stats;
	struct timeval curr_ts;
	struct rte_eth_stats curr_stats;
	uint64_t pps;
	uint64_t bps;
	struct rte_mempool * pktmbuf_pool;
	struct dpdk_ts_helper ts_helper;
	struct ether_addr eth_addr;
	char mac_addr[DPDK_MAC_ADDR_SIZE];
	char pci_addr[DPDK_PCI_ADDR_SIZE];
	unsigned char pcap_tmp_buf[RTE_ETH_PCAP_SNAPLEN];
};

static struct rte_eth_conf port_conf = {
	.rxmode = {
		.split_hdr_size = 0,
	},
	.txmode = {
		.mq_mode = ETH_MQ_TX_NONE,
	},
};

static int dpdk_init_timer(struct pcap_dpdk *pd){
	gettimeofday(&(pd->ts_helper.start_time),NULL);
	pd->ts_helper.start_cycles = rte_get_timer_cycles();
	pd->ts_helper.hz = rte_get_timer_hz();
	if (pd->ts_helper.hz == 0){
		return -1;	
	}
	return 0;
}
static inline void calculate_timestamp(struct dpdk_ts_helper *helper,struct timeval *ts)
{
	uint64_t cycles;
	// delta
	struct timeval cur_time;
	cycles = rte_get_timer_cycles() - helper->start_cycles;
	cur_time.tv_sec = (time_t)(cycles/helper->hz);
	cur_time.tv_usec = (suseconds_t)((cycles%helper->hz)*1e6/helper->hz);
	timeradd(&(helper->start_time), &cur_time, ts);
}

static uint32_t dpdk_gather_data(unsigned char *data, int len, struct rte_mbuf *mbuf)
{
	uint32_t total_len = 0;
	while (mbuf && (total_len+mbuf->data_len) < len ){
		rte_memcpy(data+total_len, rte_pktmbuf_mtod(mbuf,void *),mbuf->data_len);
		total_len+=mbuf->data_len;
		mbuf=mbuf->next;
	}
	return total_len;
}


static int dpdk_read_with_timeout(pcap_t *p, uint16_t portid, uint16_t queueid,struct rte_mbuf **pkts_burst, const uint16_t burst_cnt){
	struct pcap_dpdk *pd = (struct pcap_dpdk*)(p->priv);
	int nb_rx = 0;	
	int timeout_ms = p->opt.timeout;
	int sleep_ms = 0;
	if (pd->nonblock){
		// In non-blocking mode, just read once, no mater how many packets are captured.
		nb_rx = (int)rte_eth_rx_burst(pd->portid, 0, pkts_burst, burst_cnt);
	}else{
		// In blocking mode, read many times until packets are captured or timeout or break_loop is setted.	
		// if timeout_ms == 0, it may be blocked forever.
		while (timeout_ms == 0 || sleep_ms < timeout_ms){
			nb_rx = (int)rte_eth_rx_burst(pd->portid, 0, pkts_burst, burst_cnt);
			if (nb_rx){ // got packets within timeout_ms
				break;	
			}else{ // no packet arrives at this round.
				if (p->break_loop){
					break;
				}
				// sleep for a very short while.
				// block sleep is the only choice, since usleep() will impact performance dramatically.
				rte_delay_us_block(DPDK_DEF_MIN_SLEEP_MS*1000);
				sleep_ms += DPDK_DEF_MIN_SLEEP_MS;
			}
		}
	}
	return nb_rx;
}

static int pcap_dpdk_dispatch(pcap_t *p, int max_cnt, pcap_handler cb, u_char *cb_arg)
{
	struct pcap_dpdk *pd = (struct pcap_dpdk*)(p->priv);
	int burst_cnt = 0;
	int nb_rx = 0;
	struct rte_mbuf *pkts_burst[MAX_PKT_BURST];
	struct rte_mbuf *m;
	struct pcap_pkthdr pcap_header;
	uint16_t portid = pd->portid;
	// In DPDK, pkt_len is sum of lengths for all segments. And data_len is for one segment
	uint32_t pkt_len = 0;
	int caplen = 0;
	u_char *bp = NULL;
	int i=0;
	unsigned int gather_len =0;
	int pkt_cnt = 0;
	int is_accepted=0;
	u_char *large_buffer=NULL;
	int timeout_ms = p->opt.timeout;

	if ( !PACKET_COUNT_IS_UNLIMITED(max_cnt) && max_cnt < MAX_PKT_BURST){
		burst_cnt = max_cnt;
	}else{
		burst_cnt = MAX_PKT_BURST;
	}

	while( PACKET_COUNT_IS_UNLIMITED(max_cnt) || pkt_cnt < max_cnt){
		if (p->break_loop){
			p->break_loop = 0;
			return PCAP_ERROR_BREAK;
		}
		// read once in non-blocking mode, or try many times waiting for timeout_ms.
		// if timeout_ms == 0, it will be blocked until one packet arrives or break_loop is setted.
		nb_rx = dpdk_read_with_timeout(p, portid, 0, pkts_burst, burst_cnt);
		if (nb_rx == 0){ 
			if (pd->nonblock){
				RTE_LOG(DEBUG, USER1, "dpdk: no packets available in non-blocking mode.\n");
			}else{
				if (p->break_loop){
					RTE_LOG(DEBUG, USER1, "dpdk: no packets available and break_loop is setted in blocking mode.\n");
					p->break_loop = 0;
					return PCAP_ERROR_BREAK;

				}
				RTE_LOG(DEBUG, USER1, "dpdk: no packets available for timeout %d ms in blocking mode.\n", timeout_ms);
			}
			// break if dpdk reads 0 packet, no matter in blocking(timeout) or non-blocking mode.
			break;	
		}
		pkt_cnt += nb_rx;
		for ( i = 0; i < nb_rx; i++) {
			m = pkts_burst[i];
			calculate_timestamp(&(pd->ts_helper),&(pcap_header.ts));
			pkt_len = rte_pktmbuf_pkt_len(m);
			// caplen = min(pkt_len, p->snapshot);
			// caplen will not be changed, no matter how long the rte_pktmbuf
			caplen = pkt_len < p->snapshot ? pkt_len: p->snapshot; 
			pcap_header.caplen = caplen;
			pcap_header.len = pkt_len; 
			// volatile prefetch
			rte_prefetch0(rte_pktmbuf_mtod(m, void *));
			bp = NULL;
			if (m->nb_segs == 1)
			{
				bp = rte_pktmbuf_mtod(m, u_char *);
			}else{
				// use fast buffer pcap_tmp_buf if pkt_len is small, no need to call malloc and free
				if ( pkt_len <= ETHER_MAX_JUMBO_FRAME_LEN)
				{
					gather_len = dpdk_gather_data(pd->pcap_tmp_buf, RTE_ETH_PCAP_SNAPLEN, m);
					bp = pd->pcap_tmp_buf;
				}else{ 
					// need call free later
					large_buffer = (u_char *)malloc(caplen*sizeof(u_char));
					gather_len = dpdk_gather_data(large_buffer, caplen, m); 
					bp = large_buffer;
				}
				
			}
			if (bp){
				if (p->fcode.bf_insns==NULL || pcap_filter(p->fcode.bf_insns, bp, pcap_header.len, pcap_header.caplen)){
					cb(cb_arg, &pcap_header, bp);
				}else{
					pd->bpf_drop++;
				}
			}
			//free all pktmbuf
			rte_pktmbuf_free(m);
			if (large_buffer){
				free(large_buffer);
				large_buffer=NULL;
			}
		}
	}	
	return pkt_cnt;
}

static int pcap_dpdk_inject(pcap_t *p, const void *buf _U_, int size _U_)
{
	//not implemented yet
	pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
		errno, "dpdk error: Inject function has not been implemented yet");
	return PCAP_ERROR;
}

static void pcap_dpdk_close(pcap_t *p)
{
	struct pcap_dpdk *pd = p->priv;
	if (pd==NULL)
	{
		return;
	} 
	if (pd->must_clear_promisc)
	{
		rte_eth_promiscuous_disable(pd->portid);
	}
	rte_eth_dev_stop(pd->portid);
	rte_eth_dev_close(pd->portid);
	pcap_cleanup_live_common(p);
} 

static void nic_stats_display(struct pcap_dpdk *pd)
{
	uint16_t portid = pd->portid;
	struct rte_eth_stats stats;
	rte_eth_stats_get(portid, &stats);
	RTE_LOG(INFO,USER1, "portid:%d, RX-packets: %-10"PRIu64"  RX-errors:  %-10"PRIu64
	       "  RX-bytes:  %-10"PRIu64"  RX-Imissed:  %-10"PRIu64"\n", portid, stats.ipackets, stats.ierrors,
	       stats.ibytes,stats.imissed);
	RTE_LOG(INFO,USER1, "portid:%d, RX-PPS: %-10"PRIu64" RX-Mbps: %.2lf\n", portid, pd->pps, pd->bps/1e6f );
}

static int pcap_dpdk_stats(pcap_t *p, struct pcap_stat *ps)
{
	struct pcap_dpdk *pd = p->priv;
	calculate_timestamp(&(pd->ts_helper), &(pd->curr_ts));
	rte_eth_stats_get(pd->portid,&(pd->curr_stats));
	if (ps){
		ps->ps_recv = pd->curr_stats.ipackets;
		ps->ps_drop = pd->curr_stats.ierrors;
		ps->ps_drop += pd->bpf_drop;
		ps->ps_ifdrop = pd->curr_stats.imissed;
	}
	uint64_t delta_pkt = pd->curr_stats.ipackets - pd->prev_stats.ipackets;
	struct timeval delta_tm;
	timersub(&(pd->curr_ts),&(pd->prev_ts), &delta_tm);
	uint64_t delta_usec = delta_tm.tv_sec*1e6+delta_tm.tv_usec;
	uint64_t delta_bit = (pd->curr_stats.ibytes-pd->prev_stats.ibytes)*8;
	RTE_LOG(DEBUG, USER1, "delta_usec: %-10"PRIu64" delta_pkt: %-10"PRIu64" delta_bit: %-10"PRIu64"\n", delta_usec, delta_pkt, delta_bit);
	pd->pps = (uint64_t)(delta_pkt*1e6f/delta_usec);
	pd->bps = (uint64_t)(delta_bit*1e6f/delta_usec);
	nic_stats_display(pd);
	pd->prev_stats = pd->curr_stats;
	pd->prev_ts = pd->curr_ts;
	return 0;
}

static int pcap_dpdk_setnonblock(pcap_t *p, int nonblock){
	struct pcap_dpdk *pd = (struct pcap_dpdk*)(p->priv);
	pd->nonblock = nonblock;
	return 0;
}

static int pcap_dpdk_getnonblock(pcap_t *p){
	struct pcap_dpdk *pd = (struct pcap_dpdk*)(p->priv);
	return pd->nonblock;
}
static int check_link_status(uint16_t portid, struct rte_eth_link *plink)
{
	// wait up to 9 seconds to get link status
	rte_eth_link_get(portid, plink);
	return plink->link_status == ETH_LINK_UP;
}
static void eth_addr_str(struct ether_addr *addrp, char* mac_str, int len)
{
	int offset=0;
	if (addrp == NULL){
		pcap_snprintf(mac_str, len-1, DPDK_DEF_MAC_ADDR);
		return;
	}
	for (int i=0; i<6; i++)
	{
		if (offset >= len)
		{ // buffer overflow
			return;
		}
		if (i==0)
		{
			pcap_snprintf(mac_str+offset, len-1-offset, "%02X",addrp->addr_bytes[i]);
			offset+=2; // FF
		}else{
			pcap_snprintf(mac_str+offset, len-1-offset, ":%02X", addrp->addr_bytes[i]);
			offset+=3; // :FF
		}
	}
	return;
}
// return portid by device name, otherwise return -1
static uint16_t portid_by_device(char * device)
{
	uint16_t ret = DPDK_PORTID_MAX; 
	int len = strlen(device);
	int prefix_len = strlen(DPDK_PREFIX);
	unsigned long ret_ul = 0L;
	char *pEnd;
	if (len<=prefix_len || strncmp(device, DPDK_PREFIX, prefix_len)) // check prefix dpdk:
	{
		return ret;
	}
	//check all chars are digital
	for (int i=prefix_len; device[i]; i++){
		if (device[i]<'0' || device[i]>'9'){
			return ret;	
		}
	}
	ret_ul = strtoul(&(device[prefix_len]), &pEnd, 10);
	if (pEnd == &(device[prefix_len]) || *pEnd != '\0'){
		return ret;
	}
	// too large for portid
	if (ret_ul >= DPDK_PORTID_MAX){ 
		return ret;
	}
	ret = (uint16_t)ret_ul;
	return ret;
}

static int parse_dpdk_cfg(char* dpdk_cfg,char** dargv)
{
	int cnt=0;
	memset(dargv,0,sizeof(dargv[0])*DPDK_ARGC_MAX);	
	//current process name
	int skip_space = 1;
	int i=0;
	RTE_LOG(INFO, USER1,"dpdk cfg: %s\n",dpdk_cfg);
	// find first non space char
	// The last opt is NULL
	for (i=0;dpdk_cfg[i] && cnt<DPDK_ARGC_MAX-1;i++){
		if (skip_space && dpdk_cfg[i]!=' '){ // not space
			skip_space=!skip_space; // skip normal char
			dargv[cnt++] = dpdk_cfg+i;
		}
		if (!skip_space && dpdk_cfg[i]==' '){ // fint a space
			dpdk_cfg[i]=0x00; // end of this opt
			skip_space=!skip_space; // skip space char
		}
	}
	dargv[cnt]=NULL;
	return cnt;
}

// only called once
static int dpdk_pre_init(char * ebuf)
{
	int dargv_cnt=0;
	char *dargv[DPDK_ARGC_MAX];
	char *ptr_dpdk_cfg = NULL;
	int ret = PCAP_ERROR; 
	// globale var
	if (is_dpdk_pre_inited)
	{
		// already inited
		return 0;
	}
	// check for root permission
	if( geteuid() != 0)
	{
		RTE_LOG(ERR, USER1, "%s\n", DPDK_ERR_PERM_MSG);
		pcap_fmt_errmsg_for_errno(ebuf, PCAP_ERRBUF_SIZE,
			    errno, "dpdk error: %s",
			    DPDK_ERR_PERM_MSG);
		ret = PCAP_ERROR_PERM_DENIED;
		return ret;	
	}
	// init EAL
	ptr_dpdk_cfg = getenv(DPDK_CFG_ENV_NAME);
	// set default log level to debug
	rte_log_set_global_level(DPDK_DEF_LOG_LEV);
	if (ptr_dpdk_cfg == NULL)
	{
		RTE_LOG(INFO,USER1,"env $DPDK_CFG is unset, so using default: %s\n",DPDK_DEF_CFG);
		ptr_dpdk_cfg = DPDK_DEF_CFG;
	}
	memset(dpdk_cfg_buf,0,sizeof(dpdk_cfg_buf));
	snprintf(dpdk_cfg_buf,DPDK_CFG_MAX_LEN-1,"%s %s",DPDK_LIB_NAME,ptr_dpdk_cfg);
	dargv_cnt = parse_dpdk_cfg(dpdk_cfg_buf,dargv);
	ret = rte_eal_init(dargv_cnt,dargv);
	// if init successed, we do not need to do it again later.
	if (ret == 0){
		is_dpdk_pre_inited = 1;
	}
	return ret;
}

static int pcap_dpdk_activate(pcap_t *p)
{
	struct pcap_dpdk *pd = p->priv;
	pd->orig = p;
	int ret = PCAP_ERROR;
	uint16_t nb_ports=0;
	uint16_t portid= DPDK_PORTID_MAX;
	unsigned nb_mbufs = DPDK_NB_MBUFS;
	struct rte_eth_rxconf rxq_conf;
	struct rte_eth_txconf txq_conf;
	struct rte_eth_conf local_port_conf = port_conf;
	struct rte_eth_dev_info dev_info;
	int is_port_up = 0;
	struct rte_eth_link link;
	do{
		//init EAL
		ret = dpdk_pre_init(p->errbuf);
		if (ret < 0)
		{
			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
			    errno, "dpdk error: Init failed with device %s",
			    p->opt.device);
			ret = PCAP_ERROR;
			break;
		}
		ret = dpdk_init_timer(pd);
		if (ret<0)
		{
			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
				errno, "dpdk error: Init timer error with device %s",
				p->opt.device);
			ret = PCAP_ERROR;
			break;
		}

		nb_ports = rte_eth_dev_count_avail();
		if (nb_ports == 0)
		{
			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
			    errno, "dpdk error: No Ethernet ports");
			ret = PCAP_ERROR;
			break;
		}

		portid = portid_by_device(p->opt.device);
		if (portid == DPDK_PORTID_MAX){
			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
			    errno, "dpdk error: portid is invalid. device %s",
			    p->opt.device);
			ret = PCAP_ERROR_NO_SUCH_DEVICE;
			break;
		}

		pd->portid = portid;

		if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN)
		{
			p->snapshot = MAXIMUM_SNAPLEN;
		}
		// create the mbuf pool 
		pd->pktmbuf_pool = rte_pktmbuf_pool_create(MBUF_POOL_NAME, nb_mbufs,
			MEMPOOL_CACHE_SIZE, 0, RTE_MBUF_DEFAULT_BUF_SIZE,
			rte_socket_id());
		if (pd->pktmbuf_pool == NULL)
		{
			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
			    errno, "dpdk error: Cannot init mbuf pool");
			ret = PCAP_ERROR;
			break;
		}
		// config dev
		rte_eth_dev_info_get(portid, &dev_info);
		if (dev_info.tx_offload_capa & DEV_TX_OFFLOAD_MBUF_FAST_FREE)
		{
			local_port_conf.txmode.offloads |=DEV_TX_OFFLOAD_MBUF_FAST_FREE;
		}
		// only support 1 queue
		ret = rte_eth_dev_configure(portid, 1, 1, &local_port_conf);
		if (ret < 0)
		{
			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
			    errno, "dpdk error: Cannot configure device: err=%d, port=%u",
			    ret, portid);
			ret = PCAP_ERROR;
			break;	
		}
		// adjust rx tx
		ret = rte_eth_dev_adjust_nb_rx_tx_desc(portid, &nb_rxd, &nb_txd);
		if (ret < 0)
		{
			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
			    errno, "dpdk error: Cannot adjust number of descriptors: err=%d, port=%u",
			    ret, portid);
			ret = PCAP_ERROR;
			break;	
		}
		// get MAC addr
		rte_eth_macaddr_get(portid, &(pd->eth_addr));
		eth_addr_str(&(pd->eth_addr), pd->mac_addr, DPDK_MAC_ADDR_SIZE-1);

		// init one RX queue
		rxq_conf = dev_info.default_rxconf;
		rxq_conf.offloads = local_port_conf.rxmode.offloads;
		ret = rte_eth_rx_queue_setup(portid, 0, nb_rxd,
					     rte_eth_dev_socket_id(portid),
					     &rxq_conf,
					     pd->pktmbuf_pool);
		if (ret < 0)
		{
			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
			    errno, "dpdk error: rte_eth_rx_queue_setup:err=%d, port=%u",
			    ret, portid);
			ret = PCAP_ERROR;
			break;	
		}

		// init one TX queue 
		txq_conf = dev_info.default_txconf;
		txq_conf.offloads = local_port_conf.txmode.offloads;
		ret = rte_eth_tx_queue_setup(portid, 0, nb_txd,
				rte_eth_dev_socket_id(portid),
				&txq_conf);
		if (ret < 0)
		{
			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
			    errno, "dpdk error: rte_eth_tx_queue_setup:err=%d, port=%u",
			    ret, portid);
			ret = PCAP_ERROR;
			break;	
		}
		// Initialize TX buffers 
		tx_buffer = rte_zmalloc_socket(DPDK_TX_BUF_NAME,
				RTE_ETH_TX_BUFFER_SIZE(MAX_PKT_BURST), 0,
				rte_eth_dev_socket_id(portid));
		if (tx_buffer == NULL)
		{
			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
			    errno, "dpdk error: Cannot allocate buffer for tx on port %u", portid);
			ret = PCAP_ERROR;
			break;	
		}
		rte_eth_tx_buffer_init(tx_buffer, MAX_PKT_BURST);
		// Start device
		ret = rte_eth_dev_start(portid);
		if (ret < 0)
		{
			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
			    errno, "dpdk error: rte_eth_dev_start:err=%d, port=%u",
			    ret, portid);
			ret = PCAP_ERROR;
			break;
		}
		// set promiscuous mode
		if (p->opt.promisc){
			pd->must_clear_promisc=1;
			rte_eth_promiscuous_enable(portid);
		}
		// check link status
		is_port_up = check_link_status(portid, &link);
		if (!is_port_up){
			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
			    errno, "dpdk error: link is down, port=%u",portid);
			ret = PCAP_ERROR_IFACE_NOT_UP;
			break;
		}
		// reset statistics
		rte_eth_stats_reset(pd->portid);
		calculate_timestamp(&(pd->ts_helper), &(pd->prev_ts));
		rte_eth_stats_get(pd->portid,&(pd->prev_stats));	
		// format pcap_t 
		pd->portid = portid;
		p->fd = pd->portid; 
		if (p->snapshot <=0 || p->snapshot> MAXIMUM_SNAPLEN)
		{
			p->snapshot = MAXIMUM_SNAPLEN;
		}
		p->linktype = DLT_EN10MB; // Ethernet, the 10MB is historical.
		p->selectable_fd = p->fd;
		p->read_op = pcap_dpdk_dispatch;
		p->inject_op = pcap_dpdk_inject;
		// using pcap_filter currently, though DPDK provides their own BPF function. Because DPDK BPF needs load a ELF file as a filter.
		p->setfilter_op = install_bpf_program;
		p->setdirection_op = NULL;
		p->set_datalink_op = NULL;
		p->getnonblock_op = pcap_dpdk_getnonblock;
		p->setnonblock_op = pcap_dpdk_setnonblock;
		p->stats_op = pcap_dpdk_stats;
		p->cleanup_op = pcap_dpdk_close;
		p->breakloop_op = pcap_breakloop_common;
		// set default timeout
		pd->required_select_timeout.tv_sec = 0;
		pd->required_select_timeout.tv_usec = DPDK_DEF_MIN_SLEEP_MS*1000;
		p->required_select_timeout = &pd->required_select_timeout;
		ret = 0; // OK
	}while(0);

	if (ret <= PCAP_ERROR) // all kinds of error code
	{
		pcap_cleanup_live_common(p);
	}else{
		rte_eth_dev_get_name_by_port(portid,pd->pci_addr);
		RTE_LOG(INFO, USER1,"Port %d device: %s, MAC:%s, PCI:%s\n", portid, p->opt.device, pd->mac_addr, pd->pci_addr);
		RTE_LOG(INFO, USER1,"Port %d Link Up. Speed %u Mbps - %s\n",
							portid, link.link_speed,
					(link.link_duplex == ETH_LINK_FULL_DUPLEX) ?
						("full-duplex") : ("half-duplex\n"));
	}
	return ret;
}

// device name for dpdk shoud be in the form as dpdk:number, such as dpdk:0
pcap_t * pcap_dpdk_create(const char *device, char *ebuf, int *is_ours)
{
	pcap_t *p=NULL;
	*is_ours = 0;

	*is_ours = !strncmp(device, "dpdk:", 5);
	if (! *is_ours)
		return NULL;
	//memset will happen
	p = pcap_create_common(ebuf, sizeof(struct pcap_dpdk));
		
	if (p == NULL)
		return NULL;
	p->activate_op = pcap_dpdk_activate;
	return p;
}

int pcap_dpdk_findalldevs(pcap_if_list_t *devlistp, char *ebuf)
{
	int ret=0;
	unsigned int nb_ports = 0;
	char dpdk_name[DPDK_DEV_NAME_MAX];
	char dpdk_desc[DPDK_DEV_DESC_MAX];
	struct ether_addr eth_addr;
	char mac_addr[DPDK_MAC_ADDR_SIZE];
	char pci_addr[DPDK_PCI_ADDR_SIZE];
	do{
		ret = dpdk_pre_init(ebuf);
		if (ret < 0)
		{
			pcap_fmt_errmsg_for_errno(ebuf, PCAP_ERRBUF_SIZE,
			    errno, "error: Init failed with device");
			ret = PCAP_ERROR;
			break;
		}
		nb_ports = rte_eth_dev_count_avail();
		if (nb_ports == 0)
		{
			pcap_fmt_errmsg_for_errno(ebuf, PCAP_ERRBUF_SIZE,
			    errno, "DPDK error: No Ethernet ports");
			ret = PCAP_ERROR;
			break;
		}
		for (unsigned int i=0; i<nb_ports; i++){
			pcap_snprintf(dpdk_name, DPDK_DEV_NAME_MAX-1,
			    "%s%u", DPDK_PREFIX, i);
			// mac addr 
			rte_eth_macaddr_get(i, &eth_addr);
			eth_addr_str(&eth_addr,mac_addr,DPDK_MAC_ADDR_SIZE);	
			// PCI addr
			rte_eth_dev_get_name_by_port(i,pci_addr);
			pcap_snprintf(dpdk_desc,DPDK_DEV_DESC_MAX-1,"%s %s, MAC:%s, PCI:%s", DPDK_DESC, dpdk_name, mac_addr, pci_addr);
			if (add_dev(devlistp, dpdk_name, 0, dpdk_desc, ebuf)==NULL){
				ret = PCAP_ERROR;
				break;
			}
		}	
	}while(0);	
	return ret;
}

#ifdef DPDK_ONLY
/*
 * This libpcap build supports only DPDK, not regular network interfaces.
 */

/*
 * There are no regular interfaces, just DPDK interfaces.
 */
int
pcap_platform_finddevs(pcap_if_list_t *devlistp _U_, char *errbuf)
{
	return (0);
}

/*
 * Attempts to open a regular interface fail.
 */
pcap_t *
pcap_create_interface(const char *device, char *errbuf)
{
	pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
	    "This version of libpcap only supports DPDK");
	return NULL;
}

/*
 * Libpcap version string.
 */
const char *
pcap_lib_version(void)
{
	return (PCAP_VERSION_STRING " (DPDK-only)");
}
#endif