[feat] add pcap inject demo

linux/pcap/main_inject.c

@@ -0,0 +1,51 @@
+#include <pcap.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+
+static const uint8_t test_frame[42] = {
+    0x11, 0x22, 0x33, 0x44, 0x55, 0x66,                         // dst mac b0:7b:25:00:89:53
+    0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc,                         // src mac
+    0x08, 0x06, 0x00, 0x01, 0x08, 0x00, 0x06, 0x04, 0x00, 0x02, // arp reply
+    0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc,                         // src mac
+    10, 11, 12, 13,                                             // src ip 192.168.123.100
+    0x11, 0x22, 0x33, 0x44, 0x55, 0x66,                         // dst mac b0:7b:25:00:89:53
+    14, 15, 16, 17                                              // dst ip 192.168.123.178
+};
+
+int main() {
+    char errbuf[PCAP_ERRBUF_SIZE];
+    pcap_t *handle;
+
+    // 打开网络设备
+    handle = pcap_open_live("eno1", BUFSIZ, 0, 1000, errbuf);
+    if (handle == NULL) {
+        fprintf(stderr, "Couldn't open device: %s\n", errbuf);
+        return 1;
+    }
+
+    // 构建数据包
+    u_char packet[1024];
+    int packet_len = 0;
+    memcpy(packet, test_frame, 42);
+    packet_len = 42;
+
+    // 发送数据包
+    int ret = pcap_inject(handle, packet, packet_len);
+    if (ret == -1) {
+        fprintf(stderr, "Couldn't send packet: %s\n", pcap_geterr(handle));
+        pcap_close(handle);
+        return 1;
+    } else {
+        printf("Packet sent successfully (%d bytes)\n", ret);
+    }
+
+    // 关闭网络设备
+    pcap_close(handle);
+
+    return 0;
+}