DPDK 是否可以从 rte_mbuff 数组中删除 rte_mbuff？

Question

我想删除 r 中的 arp pakcet 并正常发送另一个数据包。 这是我的代码

for (;;) {
    /*
     * Receive packets on a port and forward them on the paired
     * port. The mapping is 0 -> 1, 1 -> 0, 2 -> 3, 3 -> 2, etc.
     */
    RTE_ETH_FOREACH_DEV(port) {
        /* Get burst of RX packets, from first port of pair. */
        struct rte_mbuf *bufs[BURST_SIZE];
        uint16_t nb_rx = rte_eth_rx_burst(port, 0,
                bufs, BURST_SIZE);
        if (unlikely(nb_rx == 0))
            continue;
        /* Send burst of TX packets, to second port of pair. */
    int delete_packet_num = 0;
    for(int i=0;i<nb_rx;i++){
        struct rte_mbuf *p = bufs[i];
        unsigned char *payload =(unsigned char*)p->buf_addr;
        payload = payload+p->data_off;
        struct ethhdr* eth_hdr = (struct ethhdr *)payload;
        if(eth_hdr->h_proto == 1544)
        {
            printf("there is a arp packet!\n");
            //remove a target mbuf or not?
            rte_pktmbuf_free(bufs[i]);
            delete_packet_num++;        
        }
    
    }
    nb_rx -=delete_packet_num;
    const uint16_t nb_tx = rte_eth_tx_burst(port ^ 1, 0,bufs, nb_rx);    
    if (unlikely(nb_tx < nb_rx)) {
        uint16_t buf;
        for (buf = nb_tx; buf < nb_rx; buf++)
            rte_pktmbuf_free(bufs[buf]);
    }
}

它可以拒绝我的 vmware 机器中的 arp 数据包。但是当代码运行大约半小时分钟时，vm 机器变得非常慢。我猜是：

rte_pktmbuf_free(bufs[i])

代码不会释放内存。 谁能帮帮我？

Answer 1

如 cmets 中所述，释放 ARP 数据包后内存使用不正确。因此，要使用的正确代码是

for (;;) {
    /*
     * Receive packets on a port and forward them on the paired
     * port. The mapping is 0 -> 1, 1 -> 0, 2 -> 3, 3 -> 2, etc.
     */
    RTE_ETH_FOREACH_DEV(port) {
        /* Get burst of RX packets, from first port of pair. */
        struct rte_mbuf *bufs[BURST_SIZE];
        uint16_t nb_rx = rte_eth_rx_burst(port, 0, bufs, BURST_SIZE);
        
        if (unlikely(nb_rx == 0))
            continue;

        /* Send burst of TX packets, to second port of pair. */
        int delete_packet_num = 0;
        int i = 0, j = 0;
        
        for(;i<nb_rx;i++){
            struct rte_mbuf *p = bufs[i];
            
            unsigned char *payload =(unsigned char*)p->buf_addr;
            payload = payload+p->data_off;
            struct ethhdr* eth_hdr = (struct ethhdr *)payload;
            
            if(eth_hdr->h_proto == 1544)
            {
                printf("there is a arp packet!\n");
                //remove a target mbuf or not?
                rte_pktmbuf_free(bufs[i]);
                delete_packet_num++;        
            }
            else
            {
                /*
                 for all valid packets update the list 
                 example:
                    - let nb_rx be 16 packets
                    - in which packet at index 5 is ARP packets
                    - with help of check for ARP we are reassigning bufs[5] = bufs[6], because j is running 1 step once it encounters ARP at index 5
                 */
                bufs[j++] = bufs[i];
            }
        }
    
    nb_rx -=delete_packet_num;
    const uint16_t nb_tx = rte_eth_tx_burst(port ^ 1, 0,bufs, nb_rx);    
    if (unlikely(nb_tx < nb_rx)) {
        uint16_t buf;
        for (buf = nb_tx; buf < nb_rx; buf++)
            rte_pktmbuf_free(bufs[buf]);
    }
}