support p->snapshot

[libpcap] / pcap-dpdk.c

diff --git a/pcap-dpdk.c b/pcap-dpdk.c
index 5cb57ef9c218161b06694e3be919386296ea62ac..81e29e92ae2fcc97360bea578765f31ea4d108db 100644 (file)
--- a/pcap-dpdk.c
+++ b/pcap-dpdk.c
@@ -200,10 +200,10 @@ static inline void calculate_timestamp(struct dpdk_ts_helper *helper,struct time
        timeradd(&(helper->start_time), &cur_time, ts);
 }
 
-static unsigned int dpdk_gather_data(unsigned char *data, struct rte_mbuf *mbuf)
+static uint32_t dpdk_gather_data(unsigned char *data, int len, struct rte_mbuf *mbuf)
 {
-       unsigned int total_len = 0;
-       while (mbuf && (total_len+mbuf->data_len) < RTE_ETH_PCAP_SNAPLEN ){
+       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;
@@ -234,12 +234,16 @@ static void dpdk_dispatch_inter(void *dpdk_user)
        uint16_t portid = pd->portid;
        unsigned lcore_id = rte_lcore_id();
        unsigned master_lcore_id = rte_get_master_lcore();
+       // In DPDK, pkt_len is sum of lengths for all segments. And data_len is for one segment
        uint16_t data_len = 0;
+       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;
                
        if(lcore_id == master_lcore_id){
                RTE_LOG(DEBUG, USER1, "dpdk: lcoreid=%u runs for portid=%u\n", lcore_id, portid);
@@ -260,8 +264,12 @@ static void dpdk_dispatch_inter(void *dpdk_user)
                        m = pkts_burst[i];
                        calculate_timestamp(&(pd->ts_helper),&(pcap_header.ts));
                        data_len = rte_pktmbuf_data_len(m);
-                       pcap_header.caplen = data_len; 
-                       pcap_header.len = data_len; 
+                       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;
@@ -269,13 +277,18 @@ static void dpdk_dispatch_inter(void *dpdk_user)
                        {
                                bp = rte_pktmbuf_mtod(m, u_char *);
                        }else{
-                               if (m->pkt_len <= ETHER_MAX_JUMBO_FRAME_LEN)
+                               // 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, m);
+                                       gather_len = dpdk_gather_data(pd->pcap_tmp_buf, RTE_ETH_PCAP_SNAPLEN, m);
                                        bp = pd->pcap_tmp_buf;
-                                       pcap_header.caplen = gather_len;
-                                       pcap_header.len = gather_len;
+                               }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){
                                //default accpet all
@@ -295,6 +308,10 @@ static void dpdk_dispatch_inter(void *dpdk_user)
                        }
                        //free all pktmbuf
                        rte_pktmbuf_free(m);
+                       if (large_buffer){
+                               free(large_buffer);
+                               large_buffer=NULL;
+                       }
                }
        }       
        pd->rx_pkts = pkt_cnt;