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kernel-ark/include/linux/dccp.h
Gerrit Renker 883ca833e5 dccp: Initialisation and type-checking of feature sysctls 
This patch takes care of initialising and type-checking sysctls
related to feature negotiation. Type checking is important since some
of the sysctls now directly impact the feature-negotiation process.

The sysctls are initialised with the known default values for each
feature.  For the type-checking the value constraints from RFC 4340
are used:

 * Sequence Window uses the specified Wmin=32, the maximum is ulong (4 bytes),
   tested and confirmed that it works up to 4294967295 - for Gbps speed;
 * Ack Ratio is between 0 .. 0xffff (2-byte unsigned integer);
 * CCIDs are between 0 .. 255;
 * request_retries, retries1, retries2 also between 0..255 for good measure;
 * tx_qlen is checked to be non-negative;
 * sync_ratelimit remains as before.

Notes:
------
 1. Die s@sysctl_dccp_feat@sysctl_dccp@g since the sysctls are now in feat.c.
 2. As pointed out by Arnaldo, the pattern of type-checking repeats itself in
    other places, sometimes with exactly the same kind of definitions (e.g.
    "static int zero;"). It may be a good idea (kernel janitors?) to consolidate
    type checking. For the sake of keeping the changeset small and in order not
    to affect other subsystems, I have not strived to generalise here.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Signed-off-by: David S. Miller <davem@davemloft.net>
2009-01-21 14:34:05 -08:00

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#ifndef _LINUX_DCCP_H
#define _LINUX_DCCP_H
#include <linux/types.h>
#include <asm/byteorder.h>
/**
* struct dccp_hdr - generic part of DCCP packet header
*
* @dccph_sport - Relevant port on the endpoint that sent this packet
* @dccph_dport - Relevant port on the other endpoint
* @dccph_doff - Data Offset from the start of the DCCP header, in 32-bit words
* @dccph_ccval - Used by the HC-Sender CCID
* @dccph_cscov - Parts of the packet that are covered by the Checksum field
* @dccph_checksum - Internet checksum, depends on dccph_cscov
* @dccph_x - 0 = 24 bit sequence number, 1 = 48
* @dccph_type - packet type, see DCCP_PKT_ prefixed macros
* @dccph_seq - sequence number high or low order 24 bits, depends on dccph_x
*/
struct dccp_hdr {
__be16 dccph_sport,
dccph_dport;
__u8 dccph_doff;
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u8 dccph_cscov:4,
dccph_ccval:4;
#elif defined(__BIG_ENDIAN_BITFIELD)
__u8 dccph_ccval:4,
dccph_cscov:4;
#else
#error "Adjust your <asm/byteorder.h> defines"
#endif
__sum16 dccph_checksum;
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u8 dccph_x:1,
dccph_type:4,
dccph_reserved:3;
#elif defined(__BIG_ENDIAN_BITFIELD)
__u8 dccph_reserved:3,
dccph_type:4,
dccph_x:1;
#else
#error "Adjust your <asm/byteorder.h> defines"
#endif
__u8 dccph_seq2;
__be16 dccph_seq;
};
/**
* struct dccp_hdr_ext - the low bits of a 48 bit seq packet
*
* @dccph_seq_low - low 24 bits of a 48 bit seq packet
*/
struct dccp_hdr_ext {
__be32 dccph_seq_low;
};
/**
* struct dccp_hdr_request - Connection initiation request header
*
* @dccph_req_service - Service to which the client app wants to connect
*/
struct dccp_hdr_request {
__be32 dccph_req_service;
};
/**
* struct dccp_hdr_ack_bits - acknowledgment bits common to most packets
*
* @dccph_resp_ack_nr_high - 48 bit ack number high order bits, contains GSR
* @dccph_resp_ack_nr_low - 48 bit ack number low order bits, contains GSR
*/
struct dccp_hdr_ack_bits {
__be16 dccph_reserved1;
__be16 dccph_ack_nr_high;
__be32 dccph_ack_nr_low;
};
/**
* struct dccp_hdr_response - Connection initiation response header
*
* @dccph_resp_ack - 48 bit Acknowledgment Number Subheader (5.3)
* @dccph_resp_service - Echoes the Service Code on a received DCCP-Request
*/
struct dccp_hdr_response {
struct dccp_hdr_ack_bits dccph_resp_ack;
__be32 dccph_resp_service;
};
/**
* struct dccp_hdr_reset - Unconditionally shut down a connection
*
* @dccph_reset_ack - 48 bit Acknowledgment Number Subheader (5.6)
* @dccph_reset_code - one of %dccp_reset_codes
* @dccph_reset_data - the Data 1 ... Data 3 fields from 5.6
*/
struct dccp_hdr_reset {
struct dccp_hdr_ack_bits dccph_reset_ack;
__u8 dccph_reset_code,
dccph_reset_data[3];
};
enum dccp_pkt_type {
DCCP_PKT_REQUEST = 0,
DCCP_PKT_RESPONSE,
DCCP_PKT_DATA,
DCCP_PKT_ACK,
DCCP_PKT_DATAACK,
DCCP_PKT_CLOSEREQ,
DCCP_PKT_CLOSE,
DCCP_PKT_RESET,
DCCP_PKT_SYNC,
DCCP_PKT_SYNCACK,
DCCP_PKT_INVALID,
};
#define DCCP_NR_PKT_TYPES DCCP_PKT_INVALID
static inline unsigned int dccp_packet_hdr_len(const __u8 type)
{
if (type == DCCP_PKT_DATA)
return 0;
if (type == DCCP_PKT_DATAACK ||
type == DCCP_PKT_ACK ||
type == DCCP_PKT_SYNC ||
type == DCCP_PKT_SYNCACK ||
type == DCCP_PKT_CLOSE ||
type == DCCP_PKT_CLOSEREQ)
return sizeof(struct dccp_hdr_ack_bits);
if (type == DCCP_PKT_REQUEST)
return sizeof(struct dccp_hdr_request);
if (type == DCCP_PKT_RESPONSE)
return sizeof(struct dccp_hdr_response);
return sizeof(struct dccp_hdr_reset);
}
enum dccp_reset_codes {
DCCP_RESET_CODE_UNSPECIFIED = 0,
DCCP_RESET_CODE_CLOSED,
DCCP_RESET_CODE_ABORTED,
DCCP_RESET_CODE_NO_CONNECTION,
DCCP_RESET_CODE_PACKET_ERROR,
DCCP_RESET_CODE_OPTION_ERROR,
DCCP_RESET_CODE_MANDATORY_ERROR,
DCCP_RESET_CODE_CONNECTION_REFUSED,
DCCP_RESET_CODE_BAD_SERVICE_CODE,
DCCP_RESET_CODE_TOO_BUSY,
DCCP_RESET_CODE_BAD_INIT_COOKIE,
DCCP_RESET_CODE_AGGRESSION_PENALTY,
DCCP_MAX_RESET_CODES /* Leave at the end! */
};
/* DCCP options */
enum {
DCCPO_PADDING = 0,
DCCPO_MANDATORY = 1,
DCCPO_MIN_RESERVED = 3,
DCCPO_MAX_RESERVED = 31,
DCCPO_CHANGE_L = 32,
DCCPO_CONFIRM_L = 33,
DCCPO_CHANGE_R = 34,
DCCPO_CONFIRM_R = 35,
DCCPO_NDP_COUNT = 37,
DCCPO_ACK_VECTOR_0 = 38,
DCCPO_ACK_VECTOR_1 = 39,
DCCPO_TIMESTAMP = 41,
DCCPO_TIMESTAMP_ECHO = 42,
DCCPO_ELAPSED_TIME = 43,
DCCPO_MAX = 45,
DCCPO_MIN_CCID_SPECIFIC = 128,
DCCPO_MAX_CCID_SPECIFIC = 255,
};
/* maximum size of a single TLV-encoded DCCP option (sans type/len bytes) */
#define DCCP_SINGLE_OPT_MAXLEN 253
/* DCCP CCIDS */
enum {
DCCPC_CCID2 = 2,
DCCPC_CCID3 = 3,
};
/* DCCP features (RFC 4340 section 6.4) */
enum dccp_feature_numbers {
DCCPF_RESERVED = 0,
DCCPF_CCID = 1,
DCCPF_SHORT_SEQNOS = 2,
DCCPF_SEQUENCE_WINDOW = 3,
DCCPF_ECN_INCAPABLE = 4,
DCCPF_ACK_RATIO = 5,
DCCPF_SEND_ACK_VECTOR = 6,
DCCPF_SEND_NDP_COUNT = 7,
DCCPF_MIN_CSUM_COVER = 8,
DCCPF_DATA_CHECKSUM = 9,
/* 10-127 reserved */
DCCPF_MIN_CCID_SPECIFIC = 128,
DCCPF_SEND_LEV_RATE = 192, /* RFC 4342, sec. 8.4 */
DCCPF_MAX_CCID_SPECIFIC = 255,
};
/* DCCP socket options */
#define DCCP_SOCKOPT_PACKET_SIZE 1 /* XXX deprecated, without effect */
#define DCCP_SOCKOPT_SERVICE 2
#define DCCP_SOCKOPT_CHANGE_L 3
#define DCCP_SOCKOPT_CHANGE_R 4
#define DCCP_SOCKOPT_GET_CUR_MPS 5
#define DCCP_SOCKOPT_SERVER_TIMEWAIT 6
#define DCCP_SOCKOPT_SEND_CSCOV 10
#define DCCP_SOCKOPT_RECV_CSCOV 11
#define DCCP_SOCKOPT_AVAILABLE_CCIDS 12
#define DCCP_SOCKOPT_CCID 13
#define DCCP_SOCKOPT_TX_CCID 14
#define DCCP_SOCKOPT_RX_CCID 15
#define DCCP_SOCKOPT_CCID_RX_INFO 128
#define DCCP_SOCKOPT_CCID_TX_INFO 192
/* maximum number of services provided on the same listening port */
#define DCCP_SERVICE_LIST_MAX_LEN 32
#ifdef __KERNEL__
#include <linux/in.h>
#include <linux/ktime.h>
#include <linux/list.h>
#include <linux/uio.h>
#include <linux/workqueue.h>
#include <net/inet_connection_sock.h>
#include <net/inet_sock.h>
#include <net/inet_timewait_sock.h>
#include <net/tcp_states.h>
enum dccp_state {
DCCP_OPEN = TCP_ESTABLISHED,
DCCP_REQUESTING = TCP_SYN_SENT,
DCCP_LISTEN = TCP_LISTEN,
DCCP_RESPOND = TCP_SYN_RECV,
/*
* States involved in closing a DCCP connection:
* 1) ACTIVE_CLOSEREQ is entered by a server sending a CloseReq.
*
* 2) CLOSING can have three different meanings (RFC 4340, 8.3):
* a. Client has performed active-close, has sent a Close to the server
* from state OPEN or PARTOPEN, and is waiting for the final Reset
* (in this case, SOCK_DONE == 1).
* b. Client is asked to perform passive-close, by receiving a CloseReq
* in (PART)OPEN state. It sends a Close and waits for final Reset
* (in this case, SOCK_DONE == 0).
* c. Server performs an active-close as in (a), keeps TIMEWAIT state.
*
* 3) The following intermediate states are employed to give passively
* closing nodes a chance to process their unread data:
* - PASSIVE_CLOSE (from OPEN => CLOSED) and
* - PASSIVE_CLOSEREQ (from (PART)OPEN to CLOSING; case (b) above).
*/
DCCP_ACTIVE_CLOSEREQ = TCP_FIN_WAIT1,
DCCP_PASSIVE_CLOSE = TCP_CLOSE_WAIT, /* any node receiving a Close */
DCCP_CLOSING = TCP_CLOSING,
DCCP_TIME_WAIT = TCP_TIME_WAIT,
DCCP_CLOSED = TCP_CLOSE,
DCCP_PARTOPEN = TCP_MAX_STATES,
DCCP_PASSIVE_CLOSEREQ, /* clients receiving CloseReq */
DCCP_MAX_STATES
};
#define DCCP_STATE_MASK 0x1f
enum {
DCCPF_OPEN = TCPF_ESTABLISHED,
DCCPF_REQUESTING = TCPF_SYN_SENT,
DCCPF_LISTEN = TCPF_LISTEN,
DCCPF_RESPOND = TCPF_SYN_RECV,
DCCPF_ACTIVE_CLOSEREQ = TCPF_FIN_WAIT1,
DCCPF_CLOSING = TCPF_CLOSING,
DCCPF_TIME_WAIT = TCPF_TIME_WAIT,
DCCPF_CLOSED = TCPF_CLOSE,
DCCPF_PARTOPEN = (1 << DCCP_PARTOPEN),
};
static inline struct dccp_hdr *dccp_hdr(const struct sk_buff *skb)
{
return (struct dccp_hdr *)skb_transport_header(skb);
}
static inline struct dccp_hdr *dccp_zeroed_hdr(struct sk_buff *skb, int headlen)
{
skb_push(skb, headlen);
skb_reset_transport_header(skb);
return memset(skb_transport_header(skb), 0, headlen);
}
static inline struct dccp_hdr_ext *dccp_hdrx(const struct dccp_hdr *dh)
{
return (struct dccp_hdr_ext *)((unsigned char *)dh + sizeof(*dh));
}
static inline unsigned int __dccp_basic_hdr_len(const struct dccp_hdr *dh)
{
return sizeof(*dh) + (dh->dccph_x ? sizeof(struct dccp_hdr_ext) : 0);
}
static inline unsigned int dccp_basic_hdr_len(const struct sk_buff *skb)
{
const struct dccp_hdr *dh = dccp_hdr(skb);
return __dccp_basic_hdr_len(dh);
}
static inline __u64 dccp_hdr_seq(const struct dccp_hdr *dh)
{
__u64 seq_nr = ntohs(dh->dccph_seq);
if (dh->dccph_x != 0)
seq_nr = (seq_nr << 32) + ntohl(dccp_hdrx(dh)->dccph_seq_low);
else
seq_nr += (u32)dh->dccph_seq2 << 16;
return seq_nr;
}
static inline struct dccp_hdr_request *dccp_hdr_request(struct sk_buff *skb)
{
return (struct dccp_hdr_request *)(skb_transport_header(skb) +
dccp_basic_hdr_len(skb));
}
static inline struct dccp_hdr_ack_bits *dccp_hdr_ack_bits(const struct sk_buff *skb)
{
return (struct dccp_hdr_ack_bits *)(skb_transport_header(skb) +
dccp_basic_hdr_len(skb));
}
static inline u64 dccp_hdr_ack_seq(const struct sk_buff *skb)
{
const struct dccp_hdr_ack_bits *dhack = dccp_hdr_ack_bits(skb);
return ((u64)ntohs(dhack->dccph_ack_nr_high) << 32) + ntohl(dhack->dccph_ack_nr_low);
}
static inline struct dccp_hdr_response *dccp_hdr_response(struct sk_buff *skb)
{
return (struct dccp_hdr_response *)(skb_transport_header(skb) +
dccp_basic_hdr_len(skb));
}
static inline struct dccp_hdr_reset *dccp_hdr_reset(struct sk_buff *skb)
{
return (struct dccp_hdr_reset *)(skb_transport_header(skb) +
dccp_basic_hdr_len(skb));
}
static inline unsigned int __dccp_hdr_len(const struct dccp_hdr *dh)
{
return __dccp_basic_hdr_len(dh) +
dccp_packet_hdr_len(dh->dccph_type);
}
static inline unsigned int dccp_hdr_len(const struct sk_buff *skb)
{
return __dccp_hdr_len(dccp_hdr(skb));
}
/**
* struct dccp_request_sock - represent DCCP-specific connection request
* @dreq_inet_rsk: structure inherited from
* @dreq_iss: initial sequence number sent on the Response (RFC 4340, 7.1)
* @dreq_isr: initial sequence number received on the Request
* @dreq_service: service code present on the Request (there is just one)
* @dreq_featneg: feature negotiation options for this connection
* The following two fields are analogous to the ones in dccp_sock:
* @dreq_timestamp_echo: last received timestamp to echo (13.1)
* @dreq_timestamp_echo: the time of receiving the last @dreq_timestamp_echo
*/
struct dccp_request_sock {
struct inet_request_sock dreq_inet_rsk;
__u64 dreq_iss;
__u64 dreq_isr;
__be32 dreq_service;
struct list_head dreq_featneg;
__u32 dreq_timestamp_echo;
__u32 dreq_timestamp_time;
};
static inline struct dccp_request_sock *dccp_rsk(const struct request_sock *req)
{
return (struct dccp_request_sock *)req;
}
extern struct inet_timewait_death_row dccp_death_row;
extern int dccp_parse_options(struct sock *sk, struct dccp_request_sock *dreq,
struct sk_buff *skb);
struct dccp_options_received {
u64 dccpor_ndp:48;
u32 dccpor_timestamp;
u32 dccpor_timestamp_echo;
u32 dccpor_elapsed_time;
};
struct ccid;
enum dccp_role {
DCCP_ROLE_UNDEFINED,
DCCP_ROLE_LISTEN,
DCCP_ROLE_CLIENT,
DCCP_ROLE_SERVER,
};
struct dccp_service_list {
__u32 dccpsl_nr;
__be32 dccpsl_list[0];
};
#define DCCP_SERVICE_INVALID_VALUE htonl((__u32)-1)
#define DCCP_SERVICE_CODE_IS_ABSENT 0
static inline int dccp_list_has_service(const struct dccp_service_list *sl,
const __be32 service)
{
if (likely(sl != NULL)) {
u32 i = sl->dccpsl_nr;
while (i--)
if (sl->dccpsl_list[i] == service)
return 1;
}
return 0;
}
struct dccp_ackvec;
/**
* struct dccp_sock - DCCP socket state
*
* @dccps_swl - sequence number window low
* @dccps_swh - sequence number window high
* @dccps_awl - acknowledgement number window low
* @dccps_awh - acknowledgement number window high
* @dccps_iss - initial sequence number sent
* @dccps_isr - initial sequence number received
* @dccps_osr - first OPEN sequence number received
* @dccps_gss - greatest sequence number sent
* @dccps_gsr - greatest valid sequence number received
* @dccps_gar - greatest valid ack number received on a non-Sync; initialized to %dccps_iss
* @dccps_service - first (passive sock) or unique (active sock) service code
* @dccps_service_list - second .. last service code on passive socket
* @dccps_timestamp_echo - latest timestamp received on a TIMESTAMP option
* @dccps_timestamp_time - time of receiving latest @dccps_timestamp_echo
* @dccps_l_ack_ratio - feature-local Ack Ratio
* @dccps_r_ack_ratio - feature-remote Ack Ratio
* @dccps_l_seq_win - local Sequence Window (influences ack number validity)
* @dccps_r_seq_win - remote Sequence Window (influences seq number validity)
* @dccps_pcslen - sender partial checksum coverage (via sockopt)
* @dccps_pcrlen - receiver partial checksum coverage (via sockopt)
* @dccps_send_ndp_count - local Send NDP Count feature (7.7.2)
* @dccps_ndp_count - number of Non Data Packets since last data packet
* @dccps_mss_cache - current value of MSS (path MTU minus header sizes)
* @dccps_rate_last - timestamp for rate-limiting DCCP-Sync (RFC 4340, 7.5.4)
* @dccps_featneg - tracks feature-negotiation state (mostly during handshake)
* @dccps_hc_rx_ackvec - rx half connection ack vector
* @dccps_hc_rx_ccid - CCID used for the receiver (or receiving half-connection)
* @dccps_hc_tx_ccid - CCID used for the sender (or sending half-connection)
* @dccps_options_received - parsed set of retrieved options
* @dccps_role - role of this sock, one of %dccp_role
* @dccps_hc_rx_insert_options - receiver wants to add options when acking
* @dccps_hc_tx_insert_options - sender wants to add options when sending
* @dccps_server_timewait - server holds timewait state on close (RFC 4340, 8.3)
* @dccps_xmit_timer - timer for when CCID is not ready to send
* @dccps_syn_rtt - RTT sample from Request/Response exchange (in usecs)
*/
struct dccp_sock {
/* inet_connection_sock has to be the first member of dccp_sock */
struct inet_connection_sock dccps_inet_connection;
#define dccps_syn_rtt dccps_inet_connection.icsk_ack.lrcvtime
__u64 dccps_swl;
__u64 dccps_swh;
__u64 dccps_awl;
__u64 dccps_awh;
__u64 dccps_iss;
__u64 dccps_isr;
__u64 dccps_osr;
__u64 dccps_gss;
__u64 dccps_gsr;
__u64 dccps_gar;
__be32 dccps_service;
__u32 dccps_mss_cache;
struct dccp_service_list *dccps_service_list;
__u32 dccps_timestamp_echo;
__u32 dccps_timestamp_time;
__u16 dccps_l_ack_ratio;
__u16 dccps_r_ack_ratio;
__u64 dccps_l_seq_win:48;
__u64 dccps_r_seq_win:48;
__u8 dccps_pcslen:4;
__u8 dccps_pcrlen:4;
__u8 dccps_send_ndp_count:1;
__u64 dccps_ndp_count:48;
unsigned long dccps_rate_last;
struct list_head dccps_featneg;
struct dccp_ackvec *dccps_hc_rx_ackvec;
struct ccid *dccps_hc_rx_ccid;
struct ccid *dccps_hc_tx_ccid;
struct dccp_options_received dccps_options_received;
enum dccp_role dccps_role:2;
__u8 dccps_hc_rx_insert_options:1;
__u8 dccps_hc_tx_insert_options:1;
__u8 dccps_server_timewait:1;
struct timer_list dccps_xmit_timer;
};
static inline struct dccp_sock *dccp_sk(const struct sock *sk)
{
return (struct dccp_sock *)sk;
}
static inline const char *dccp_role(const struct sock *sk)
{
switch (dccp_sk(sk)->dccps_role) {
case DCCP_ROLE_UNDEFINED: return "undefined";
case DCCP_ROLE_LISTEN: return "listen";
case DCCP_ROLE_SERVER: return "server";
case DCCP_ROLE_CLIENT: return "client";
}
return NULL;
}
#endif /* __KERNEL__ */
#endif /* _LINUX_DCCP_H */
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