ping.c File Reference

ICMP ping protocol. More...

#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <byteswap.h>
#include <ipxe/refcnt.h>
#include <ipxe/list.h>
#include <ipxe/iobuf.h>
#include <ipxe/tcpip.h>
#include <ipxe/icmp.h>
#include <ipxe/interface.h>
#include <ipxe/xfer.h>
#include <ipxe/open.h>
#include <ipxe/netdevice.h>
#include <ipxe/ping.h>

Go to the source code of this file.

Data Structures
struct	ping_connection
	A ping connection. More...

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
	FILE_SECBOOT (PERMITTED)
static	LIST_HEAD (ping_conns)
	List of registered ping connections.
static struct ping_connection *	ping_demux (unsigned int port)
	Identify ping connection by local port number.
static int	ping_port_available (int port)
	Check if local port number is available.
int	ping_rx (struct io_buffer *iobuf, struct sockaddr_tcpip *st_src)
	Process ICMP ping reply.
static struct io_buffer *	ping_alloc_iob (struct ping_connection *ping __unused, size_t len)
	Allocate I/O buffer for ping.
static int	ping_deliver (struct ping_connection *ping, struct io_buffer *iobuf, struct xfer_metadata *meta)
	Deliver datagram as I/O buffer.
static void	ping_close (struct ping_connection *ping, int rc)
	Close ping connection.
static int	ping_open (struct interface *xfer, struct sockaddr *peer, struct sockaddr *local)
	Open a ping connection.

Variables
static struct interface_operation	ping_xfer_operations []
	Ping data transfer interface operations.
static struct interface_descriptor	ping_xfer_desc
	Ping data transfer interface descriptor.
struct socket_opener ping_socket_opener	__socket_opener
	Ping socket opener.
int	ping_sock_echo = PING_SOCK_ECHO
	Linkage hack.

Detailed Description

ICMP ping protocol.

Definition in file ping.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

FILE_SECBOOT()

FILE_SECBOOT

(

PERMITTED

)

LIST_HEAD()

LIST_HEAD ( ping_conns )

static

List of registered ping connections.

ping_demux()

struct ping_connection * ping_demux ( unsigned int port )

static

Identify ping connection by local port number.

Parameters

port	Local port number

Return values

ping	Ping connection, or NULL

Definition at line 76 of file ping.c.

                                                                 {
        struct ping_connection *ping;
 
        list_for_each_entry ( ping, &ping_conns, list ) {
                if ( ping->port == port )
                        return ping;
        }
        return NULL;
}

References ping_connection::list, list_for_each_entry, NULL, ping(), and port.

Referenced by ping_port_available(), and ping_rx().

ping_port_available()

int ping_port_available ( int port )

static

Check if local port number is available.

Parameters

port	Local port number

Return values

port	Local port number, or negative error

Definition at line 92 of file ping.c.

                                            {
 
        return ( ping_demux ( port ) ? -EADDRINUSE : port );
}

References EADDRINUSE, ping_demux(), and port.

Referenced by ping_open().

ping_rx()

int ping_rx	(	struct io_buffer *	iobuf,
		struct sockaddr_tcpip *	st_src )

Process ICMP ping reply.

Parameters

iobuf	I/O buffer
st_src	Source address

Return values

rc	Return status code

Definition at line 104 of file ping.c.

                                                                       {
        struct icmp_echo *echo;
        struct ping_connection *ping;
        struct xfer_metadata meta;
        int rc;
 
        /* Sanity check: should already have been checked by ICMP layer */
        assert ( iob_len ( iobuf ) >= sizeof ( *echo ) );
        echo = iobuf->data;
 
        /* Identify connection */
        ping = ping_demux ( ntohs ( echo->ident ) );
        DBGC ( ping, "PING %p reply id %#04x seq %#04x\n",
               ping, ntohs ( echo->ident ), ntohs ( echo->sequence ) );
        if ( ! ping ) {
                rc = -ENOTCONN;
                goto discard;
        }
 
        /* Strip header, construct metadata, and pass data to upper layer */
        iob_pull ( iobuf, sizeof ( *echo ) );
        memset ( &meta, 0, sizeof ( meta ) );
        meta.src = ( ( struct sockaddr * ) st_src );
        meta.flags = XFER_FL_ABS_OFFSET;
        meta.offset = ntohs ( echo->sequence );
        return xfer_deliver ( &ping->xfer, iob_disown ( iobuf ), &meta );
 
 discard:
        free_iob ( iobuf );
        return rc;
}

References assert, io_buffer::data, DBGC, echo(), ENOTCONN, free_iob(), iob_disown, iob_len(), iob_pull, memset(), meta, ntohs, ping(), ping_demux(), rc, xfer_deliver(), and XFER_FL_ABS_OFFSET.

ping_alloc_iob()

struct io_buffer * ping_alloc_iob ( struct ping_connection *ping __unused, size_t len )

static

Allocate I/O buffer for ping.

Parameters

ping	Ping connection
len	Payload size

Return values

iobuf

I/O buffer, or NULL

Definition at line 144 of file ping.c.

                                                                     {
        size_t header_len;
        struct io_buffer *iobuf;
 
        header_len = ( MAX_LL_NET_HEADER_LEN + sizeof ( struct icmp_echo ) );
        iobuf = alloc_iob ( header_len + len );
        if ( iobuf )
                iob_reserve ( iobuf, header_len );
        return iobuf;
}

References __unused, alloc_iob(), iob_reserve, len, MAX_LL_NET_HEADER_LEN, and ping().

ping_deliver()

int ping_deliver ( struct ping_connection * ping, struct io_buffer * iobuf, struct xfer_metadata * meta )

static

Deliver datagram as I/O buffer.

Parameters

ping	Ping connection
iobuf	I/O buffer
meta	Data transfer metadata

Return values

rc	Return status code

Definition at line 163 of file ping.c.

                                                       {
        struct icmp_echo *echo = iob_push ( iobuf, sizeof ( *echo ) );
        int rc;
 
        /* Construct header */
        memset ( echo, 0, sizeof ( *echo ) );
        echo->ident = htons ( ping->port );
        echo->sequence = htons ( meta->offset );
 
        /* Transmit echo request */
        if ( ( rc = icmp_tx_echo_request ( iob_disown ( iobuf ),
                                           &ping->peer ) ) != 0 ) {
                DBGC ( ping, "PING %p could not transmit: %s\n",
                       ping, strerror ( rc ) );
                return rc;
        }
 
        return 0;
}

References DBGC, echo(), htons, icmp_tx_echo_request(), iob_disown, iob_push, memset(), meta, ping(), rc, and strerror().

ping_close()

void ping_close ( struct ping_connection * ping, int rc )

static

Close ping connection.

Parameters

ping	Ping connection
rc	Reason for close

Definition at line 190 of file ping.c.

                                                                {
 
        /* Close data transfer interface */
        intf_shutdown ( &ping->xfer, rc );
 
        /* Remove from list of connections and drop list's reference */
        list_del ( &ping->list );
        ref_put ( &ping->refcnt );
 
        DBGC ( ping, "PING %p closed\n", ping );
}

References DBGC, intf_shutdown(), list_del, ping(), rc, and ref_put.

ping_open()

int ping_open ( struct interface * xfer, struct sockaddr * peer, struct sockaddr * local )

static

Open a ping connection.

Parameters

xfer	Data transfer interface
peer	Peer socket address
local	Local socket address, or NULL

Return values

rc	Return status code

Definition at line 221 of file ping.c.

                                                {
        struct sockaddr_tcpip *st_peer = ( struct sockaddr_tcpip * ) peer;
        struct sockaddr_tcpip *st_local = ( struct sockaddr_tcpip * ) local;
        struct ping_connection *ping;
        int port;
        int rc;
 
        /* Allocate and initialise structure */
        ping = zalloc ( sizeof ( *ping ) );
        if ( ! ping ) {
                rc = -ENOMEM;
                goto err_alloc;
        }
        DBGC ( ping, "PING %p allocated\n", ping );
        ref_init ( &ping->refcnt, NULL );
        intf_init ( &ping->xfer, &ping_xfer_desc, &ping->refcnt );
        memcpy ( &ping->peer, st_peer, sizeof ( ping->peer ) );
 
        /* Bind to local port */
        port = tcpip_bind ( st_local, ping_port_available );
        if ( port < 0 ) {
                rc = port;
                DBGC ( ping, "PING %p could not bind: %s\n",
                       ping, strerror ( rc ) );
                goto err_bind;
        }
        ping->port = port;
        DBGC ( ping, "PING %p bound to id %#04x\n", ping, port );
 
        /* Attach parent interface, transfer reference to connection
         * list, and return
         */
        intf_plug_plug ( &ping->xfer, xfer );
        list_add ( &ping->list, &ping_conns );
        return 0;
 
 err_bind:
        ref_put ( &ping->refcnt );
 err_alloc:
        return rc;
}

References DBGC, ENOMEM, intf_init(), intf_plug_plug(), list_add, memcpy(), NULL, peer, ping(), ping_port_available(), ping_xfer_desc, port, rc, ref_init, ref_put, strerror(), tcpip_bind(), ping_connection::xfer, and zalloc().

Variable Documentation

ping_xfer_operations

struct interface_operation ping_xfer_operations[]

static

Initial value:

                                 = {
        INTF_OP ( xfer_deliver, struct ping_connection *, ping_deliver ),
        INTF_OP ( xfer_alloc_iob, struct ping_connection *, ping_alloc_iob ),
        INTF_OP ( intf_close, struct ping_connection *, ping_close ),
}

Ping data transfer interface operations.

Definition at line 203 of file ping.c.

                                                         {
        INTF_OP ( xfer_deliver, struct ping_connection *, ping_deliver ),
        INTF_OP ( xfer_alloc_iob, struct ping_connection *, ping_alloc_iob ),
        INTF_OP ( intf_close, struct ping_connection *, ping_close ),
};

ping_xfer_desc

struct interface_descriptor ping_xfer_desc

static

Initial value:

                         =
INTF_DESC ( struct ping_connection, xfer, ping_xfer_operations )

Ping data transfer interface descriptor.

Definition at line 210 of file ping.c.

Referenced by ping_open().

__socket_opener

struct socket_opener ping_socket_opener __socket_opener

Initial value:

                   = {
        .semantics      = PING_SOCK_ECHO,
        .open           = ping_open,
}

Ping socket opener.

Definition at line 265 of file ping.c.

                                                        {
        .semantics      = PING_SOCK_ECHO,
        .open           = ping_open,
};