writePacketv4() — netty Function Reference

Architecture documentation for the writePacketv4() function in IPPacket.java from the netty codebase.

Function java Buffer Allocators called by 2

Entity Profile

Buffer→ Allocators→ writePacketv4() — netty Function Reference

Dependency Diagram

graph TD
  156ab60f_e4aa_05ff_1736_9a0ba1b68545["writePacketv4()"]
  2a529d61_5ad1_18d2_de54_9754b754e309["IPPacket"]
  156ab60f_e4aa_05ff_1736_9a0ba1b68545 -->|defined in| 2a529d61_5ad1_18d2_de54_9754b754e309
  e1e0bffe_9a8c_499b_3405_ba1e9670ca8a["writeUDPv4()"]
  e1e0bffe_9a8c_499b_3405_ba1e9670ca8a -->|calls| 156ab60f_e4aa_05ff_1736_9a0ba1b68545
  ce6f4047_b49f_b89c_7554_affa2eb4cfca["writeTCPv4()"]
  ce6f4047_b49f_b89c_7554_affa2eb4cfca -->|calls| 156ab60f_e4aa_05ff_1736_9a0ba1b68545
  style 156ab60f_e4aa_05ff_1736_9a0ba1b68545 fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

handler/src/main/java/io/netty/handler/pcap/IPPacket.java lines 84–98

    private static void writePacketv4(ByteBuf byteBuf, ByteBuf payload, int protocol, int srcAddress,
                                      int dstAddress) {

        byteBuf.writeByte(0x45);      //  Version + IHL
        byteBuf.writeByte(0x00);      //  DSCP
        byteBuf.writeShort(V4_HEADER_SIZE + payload.readableBytes()); // Length
        byteBuf.writeShort(0x0000);   // Identification
        byteBuf.writeShort(0x0000);   // Fragment
        byteBuf.writeByte(MAX_TTL);   // TTL
        byteBuf.writeByte(protocol);  // Protocol
        byteBuf.writeShort(0);        // Checksum
        byteBuf.writeInt(srcAddress); // Source IPv4 Address
        byteBuf.writeInt(dstAddress); // Destination IPv4 Address
        byteBuf.writeBytes(payload);  // Payload of L4
    }