以下是DPDK中basicfwd例程添加输出数据包IP地址、MAC地址和TCP端口的代码示例。
首先,需要修改basicfwd.c文件中的send_packet函数。在该函数中,我们将构建一个新的数据包,并添加想要的字段(例如IP地址、MAC地址和TCP端口),然后发送数据包。
下面是实现这个功能的代码片段:
static void send_packet(struct rte_mbuf *m, uint16_t portid)
{
struct ether_hdr *eth;
struct ipv4_hdr *ipv4;
struct tcp_hdr *tcp;
// Initialize Ethernet header
eth = rte_pktmbuf_mtod(m, struct ether_hdr *);
ether_addr_copy(&ports_eth_addr[portid], ð->s_addr);
ether_addr_copy(&peer_eth_addrs[portid], ð->d_addr);
eth->ether_type = rte_cpu_to_be_16(ETHER_TYPE_IPv4);
// Initialize IPv4 header
ipv4 = (struct ipv4_hdr *)(eth + 1);
memset(ipv4, 0, sizeof(*ipv4));
ipv4->version_ihl = IP_VHL_DEF;
ipv4->type_of_service = 0;
ipv4->total_length = rte_cpu_to_be_16(sizeof(struct ipv4_hdr) +
sizeof(struct tcp_hdr));
ipv4->packet_id = 0;
ipv4->fragment_offset = 0;
ipv4->time_to_live = IP_DEFTTL;
ipv4->next_proto_id = IPPROTO_TCP;
ipv4->hdr_checksum = 0;
ipv4->src_addr = rte_cpu_to_be_32(IPv4(10, 0, 0, 1)); // Set source IP address
ipv4->dst_addr = rte_cpu_to_be_32(IPv4(10, 0, 0, 2)); // Set destination IP address
// Initialize TCP header
tcp = (struct tcp_hdr *)(ipv4 + 1);
memset(tcp, 0, sizeof(*tcp));
tcp->src_port = rte_cpu_to_be_16(1234); // Set source TCP port
tcp->dst_port = rte_cpu_to_be_16(5678); // Set destination TCP port
tcp->sent_seq = rte_cpu_to_be_32(1000);
tcp->recv_ack = rte_cpu_to_be_32(2000);
tcp->data_off = (sizeof(struct tcp_hdr) << 2) | TCP_DOFF_FLAGS;
tcp->tcp_flags = TCP_SYN_FLAG;
tcp->rx_win = rte_cpu_to_be_16(TCP_WINDOW);
// Finalize packet
m->l2_len = sizeof(struct ether_hdr);
m->l3_len = sizeof(struct ipv4_hdr);
m->pkt_len = sizeof(struct ether_hdr) +
sizeof(struct ipv4_hdr) +
sizeof(struct tcp_hdr);
m->data_len = m->pkt_len;
// Send packet out
rte_eth_tx_burst(portid, 0, &m, 1);
}
在上面的代码中,我们首先初始化以太网头部,然后初始化IPv4头部,并设置源IP地址和目标IP地址。接下来,我们初始化TCP头部,并设置源TCP端口和目标TCP端口。最后,我们将数据包长度和指针设置为正确的值,并将数据包发送出去。
需要注意的是,上述代码片段只是示例代码,实际应用中需要根据具体需求进行修改。