File syn_icmp.h¶

Zero-Heap Native ICMP Protocol Engine. More...

#include "syntropic/common/syn_defs.h"
#include "syntropic/net/syn_eth.h"
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

Classes¶

Type	Name
struct	SYN_ICMP

Public Functions¶

Type	Name
SYN_Status	syn_icmp_build_echo_request (SYN_ICMP * icmp, SYN_ETH * eth, uint32_t dst_ip, const uint8_t dst_mac, uint16_t id, uint16_t seq, const uint8_t * payload, size_t payload_len, uint8_t * frame_out, size_t * frame_len) Construct an outbound ICMP Echo Request frame.
uint16_t	syn_icmp_checksum (const void * buf, size_t len) Compute RFC 1071 Ones-Complement Internet Checksum.
SYN_Status	syn_icmp_init (SYN_ICMP * icmp) Initialize ICMP Engine Context.
SYN_Status	syn_icmp_process_packet (SYN_ICMP * icmp, const uint8_t * ip_pkt, size_t len, uint8_t * frame_tx, size_t * tx_len) Process incoming ICMP packet inside IPv4 payload.

Macros¶

Type	Name
define	SYN_ICMP_HEADER_LEN `8U`
define	SYN_ICMP_TYPE_ECHO_REPLY `0U`
define	SYN_ICMP_TYPE_ECHO_REQUEST `8U`
define	SYN_ICMP_TYPE_UNREACHABLE `3U`

Detailed Description¶

Specifications: * RFC 792 Internet Control Message Protocol * Zero dynamic memory allocation (0 bytes heap) * Types: * Type 0: Echo Reply * Type 3: Destination Unreachable * Type 8: Echo Request

Public Functions Documentation¶

function syn_icmp_build_echo_request¶

Construct an outbound ICMP Echo Request frame.

SYN_Status syn_icmp_build_echo_request (
    SYN_ICMP * icmp,
    SYN_ETH * eth,
    uint32_t dst_ip,
    const uint8_t dst_mac,
    uint16_t id,
    uint16_t seq,
    const uint8_t * payload,
    size_t payload_len,
    uint8_t * frame_out,
    size_t * frame_len
)

Parameters:

icmp Pointer to ICMP context.
eth Pointer to Ethernet context.
dst_ip 32-bit IPv4 address of destination.
dst_mac 6-byte MAC address of destination.
id Identifier.
seq Sequence number.
payload Pointer to payload data.
payload_len Payload length in bytes.
frame_out Output frame buffer (must hold at least 60 bytes).
frame_len Pointer to receive final Ethernet II frame length.

Returns:

SYN_OK on success.

function syn_icmp_checksum¶

Compute RFC 1071 Ones-Complement Internet Checksum.

uint16_t syn_icmp_checksum (
    const void * buf,
    size_t len
)

Parameters:

buf Pointer to buffer bytes.
len Length in bytes.

Returns:

16-bit Ones-Complement checksum.

function syn_icmp_init¶

Initialize ICMP Engine Context.

SYN_Status syn_icmp_init (
    SYN_ICMP * icmp
)

Parameters:

icmp Pointer to ICMP context.

Returns:

SYN_OK on success.

function syn_icmp_process_packet¶

Process incoming ICMP packet inside IPv4 payload.

SYN_Status syn_icmp_process_packet (
    SYN_ICMP * icmp,
    const uint8_t * ip_pkt,
    size_t len,
    uint8_t * frame_tx,
    size_t * tx_len
)

Automatically generates a matching Type 0 Echo Reply if a Type 8 Echo Request is received.

Parameters:

icmp Pointer to ICMP context.
ip_pkt Pointer to incoming IPv4 packet (starting at IP header).
len IP packet byte length.
frame_tx Output buffer to receive constructed Ethernet II reply frame (min 60 bytes).
tx_len Pointer to receive byte length of constructed reply frame (0 if none generated).

Returns:

SYN_OK on success.

Macro Definition Documentation¶

define SYN_ICMP_HEADER_LEN¶

#define SYN_ICMP_HEADER_LEN `8U`

Standard ICMP header length in bytes (8)

define SYN_ICMP_TYPE_ECHO_REPLY¶

#define SYN_ICMP_TYPE_ECHO_REPLY `0U`

ICMP Type 0: Echo Reply

define SYN_ICMP_TYPE_ECHO_REQUEST¶

#define SYN_ICMP_TYPE_ECHO_REQUEST `8U`

ICMP Type 8: Echo Request

define SYN_ICMP_TYPE_UNREACHABLE¶

#define SYN_ICMP_TYPE_UNREACHABLE `3U`

ICMP Type 3: Destination Unreachable

The documentation for this class was generated from the following file src/syntropic/net/syn_icmp.h