Protocols

Protocols are used to implement parsing and domain-specific functionality on top of the raw I/O functionality provided by the server.

Implementing Protocols

New protocols can be implemented by:

• Providing an implementation for each of the protocol callback types.

• Populating a ymo_proto with some protocol metadata and filling out the ymo_proto_vt vtable.

• Providing a pointer to that structure in an invocation to ymo_server_create().

Callbacks

type ymo_proto_init_cb_t

Protocol alloc/init callback type. [REQUIRED]

Individual protocols provide functions which match this signature in order to provide allocation/initialization.

Proto_data

private data for this protocol

Server

the server issuing the callback

Returns a status indicating protocol is ready for use

be separated into two distinct callbacks.

Definition

typedef ymo_status_t (*ymo_proto_init_cb_t)(
        ymo_proto_t* proto, ymo_server_t* server);

type ymo_proto_cleanup_cb_t

Protocol-level cleanup/dealloc callback type. [REQUIRED]

Individual protocols provide a function which matches this signature in order to perform cleanup/deallocation.

Proto

the protocol being destroyed

Server

the server which is issuing the callback

be separated into two distinct callbacks.

Definition

typedef void (*ymo_proto_cleanup_cb_t)(
        ymo_proto_t* proto, ymo_server_t* server);

type ymo_proto_conn_init_cb_t

Protocol-level connection init callback. [OPTIONAL]

Gives protocols a chance to do alloc/init per-connection data.

Proto_data

the protocol data against which this is being invoked.

Conn

the newly created connection object

Returns per-connection protocol data (or NULL)

Definition

typedef void* (*ymo_proto_conn_init_cb_t)(
        void* proto_data, ymo_conn_t* conn);

type ymo_proto_conn_ready_cb_t

Protocol-level connection ready callback. [OPTIONAL]

Gives protocols a chance to do “on-open” style notification to user space.

Proto_data

the protocol data against which this is being invoked.

Conn

the newly created connection object

Returns

per-connection protocol data (or NULL)

Definition

typedef ymo_status_t (*ymo_proto_conn_ready_cb_t)(
        void* proto_data, ymo_conn_t* conn, void* conn_data);

type ymo_proto_conn_cleanup_cb_t

Protocol-level connection cleanup callback.

Gives protocols a chance to do cleanup/deallocate per-connection data.

Proto_data

the protocol data against which this is being invoked

Conn

the connection object that’s being destroyed

Conn_data

the per-connection data associated with this connection

Definition

typedef void (*ymo_proto_conn_cleanup_cb_t)(
        void* proto_data,
        ymo_conn_t* conn,
        void* conn_data);

type ymo_proto_read_cb_t

Protocol-level read callback.

Definition

typedef ssize_t (*ymo_proto_read_cb_t)(
        void* proto_data,
        ymo_conn_t* conn,
        void* conn_data,
        char* buf_in,
        size_t len);

type ymo_proto_write_cb_t

Protocol-level write callback.

Definition

typedef ymo_status_t (*ymo_proto_write_cb_t)(
        void* proto_data,
        ymo_conn_t* conn,
        void* conn_data,
        int socket);

Types

struct ymo_proto_vt

Protocol callback “vtable”.

Definition

struct ymo_proto_vt {
    ymo_proto_init_cb_t          init_cb;         /* Protocol init callback */
    ymo_proto_cleanup_cb_t       cleanup_cb;      /* Protocol cleanup callback */
    ymo_proto_conn_init_cb_t     conn_init_cb;    /* Client init callback */
    ymo_proto_conn_ready_cb_t    conn_ready_cb;   /* Client ready callback */
    ymo_proto_conn_cleanup_cb_t  conn_cleanup_cb; /* Client cleanup callback */
    ymo_proto_read_cb_t          read_cb;         /* Protocol read callback */
    ymo_proto_write_cb_t         write_cb;        /* Protocol write callback */
};

struct ymo_proto

Data structure used to define a single protocol.

Definition

struct ymo_proto {
    const char*          name; /* Plain text protocol name */
    void*                data;
    struct ymo_proto_vt  vtable;
};