pccrd.h File Reference

Peer Content Caching and Retrieval: Discovery Protocol [MS-PCCRD]. More...

Go to the source code of this file.

Data Structures
struct	peerdist_discovery_block_count
	A PeerDist discovery reply block count. More...
struct	peerdist_discovery_reply
	A PeerDist discovery reply. More...

Macros
#define	PEERDIST_DISCOVERY_PORT   3702
	PeerDist discovery port. More...
#define	PEERDIST_DISCOVERY_IPV4   ( ( 239 << 24 ) | ( 255 << 16 ) | ( 255 << 8 ) | ( 250 << 0 ) )
	PeerDist discovery IPv4 address (239.255.255.250) More...
#define	PEERDIST_DISCOVERY_IPV6   { 0xff, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xc }
	PeerDist discovery IPv6 address (ff02::c) More...

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
struct peerdist_discovery_block_count	__attribute__ ((packed))
char *	peerdist_discovery_request (const char *uuid, const char *id)
	Construct discovery request. More...
int	peerdist_discovery_reply (char *data, size_t len, struct peerdist_discovery_reply *reply)
	Parse discovery reply. More...

Variables
char	hex [8]
	Count (as an eight-digit hex value) More...
struct peerdist_discovery_reply	__attribute__

Detailed Description

Peer Content Caching and Retrieval: Discovery Protocol [MS-PCCRD].

Definition in file pccrd.h.

Macro Definition Documentation

PEERDIST_DISCOVERY_PORT

#define PEERDIST_DISCOVERY_PORT   3702

PeerDist discovery port.

Definition at line 13 of file pccrd.h.

PEERDIST_DISCOVERY_IPV4

#define PEERDIST_DISCOVERY_IPV4   ( ( 239 << 24 ) | ( 255 << 16 ) | ( 255 << 8 ) | ( 250 << 0 ) )

PeerDist discovery IPv4 address (239.255.255.250)

Definition at line 16 of file pccrd.h.

PEERDIST_DISCOVERY_IPV6

#define PEERDIST_DISCOVERY_IPV6   { 0xff, 0x02, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xc }

PeerDist discovery IPv6 address (ff02::c)

Definition at line 20 of file pccrd.h.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

__attribute__()

struct peerdist_discovery_block_count __attribute__

(

(packed)

)

peerdist_discovery_request()

char* peerdist_discovery_request	(	const char *	uuid,
		const char *	id
	)

Construct discovery request.

Parameters

uuid	Message UUID string
id	Segment identifier string

Return values

request

Discovery request, or NULL on failure

The request is dynamically allocated; the caller must eventually free() the request.

Definition at line 106 of file pccrd.c.

                                                                       {
        char *request;
        int len;

        /* Construct request */
        len = asprintf ( &request, PEERDIST_DISCOVERY_REQUEST, uuid, id );
        if ( len < 0 )
                return NULL;

        return request;
}

References asprintf(), len, NULL, PEERDIST_DISCOVERY_REQUEST, and request.

Referenced by peerdisc_socket_tx().

peerdist_discovery_reply()

int peerdist_discovery_reply	(	char *	data,
		size_t	len,
		struct peerdist_discovery_reply *	reply
	)

Parse discovery reply.

Parameters

data	Reply data (not NUL-terminated, will be modified)
len	Length of reply data
reply	Discovery reply to fill in

Return values

rc	Return status code

The discovery reply includes pointers to strings within the modified reply data.

Definition at line 216 of file pccrd.c.

                                                                        {
        static const struct peerdist_discovery_block_count zcount = {
                .hex = "00000000",
        };
        struct peerdist_discovery_block_count *count;
        unsigned int max;
        unsigned int i;
        char *scopes;
        char *xaddrs;
        char *blockcount;
        char *in;
        char *out;
        size_t skip;

        /* Find <wsd:Scopes> tag */
        scopes = peerdist_discovery_reply_values ( data, len, "wsd:Scopes" );
        if ( ! scopes ) {
                DBGC ( reply, "PCCRD %p missing <wsd:Scopes> tag\n", reply );
                return -ENOENT;
        }

        /* Find <wsd:XAddrs> tag */
        xaddrs = peerdist_discovery_reply_values ( data, len, "wsd:XAddrs" );
        if ( ! xaddrs ) {
                DBGC ( reply, "PCCRD %p missing <wsd:XAddrs> tag\n", reply );
                return -ENOENT;
        }

        /* Find <PeerDist:BlockCount> tag */
        blockcount = peerdist_discovery_reply_values ( data, len,
                                                       "PeerDist:BlockCount" );
        if ( ! blockcount ) {
                DBGC ( reply, "PCCRD %p missing <PeerDist:BlockCount> tag\n",
                       reply );
                return -ENOENT;
        }

        /* Determine maximum number of segments (according to number
         * of entries in the block count list).
         */
        max = ( strlen ( blockcount ) / sizeof ( *count ) );
        count = container_of ( blockcount,
                               struct peerdist_discovery_block_count, hex[0] );

        /* Eliminate any segments with a zero block count */
        for ( i = 0, in = scopes, out = scopes ; *in ; i++, in += skip ) {

                /* Fail if we have overrun the maximum number of segments */
                if ( i >= max ) {
                        DBGC ( reply, "PCCRD %p too many segment IDs\n",
                               reply );
                        return -EPROTO;
                }

                /* Delete segment if block count is zero */
                skip = ( strlen ( in ) + 1 /* NUL */ );
                if ( memcmp ( count[i].hex, zcount.hex,
                              sizeof ( zcount.hex ) ) == 0 )
                        continue;
                strcpy ( out, in );
                out += skip;
        }
        out[0] = '\0'; /* Ensure list is terminated with a zero-length string */

        /* Fill in discovery reply */
        reply->ids = scopes;
        reply->locations = xaddrs;

        return 0;
}

References container_of, count, data, DBGC, ENOENT, EPROTO, hex, peerdist_discovery_block_count::hex, peerdist_discovery_reply::ids, in, len, peerdist_discovery_reply::locations, max, memcmp(), out, peerdist_discovery_reply_values(), strcpy(), and strlen().

Variable Documentation

hex

char hex[8]

Count (as an eight-digit hex value)

Definition at line 12 of file pccrd.h.

Referenced by peerdist_discovery_reply(), and vcprintf().

__attribute__

struct peerdist_discovery_reply __attribute__