Lines Matching refs:the
23 needs to be enabled in order for the protocol to function properly. In the Linux
24 implementation, this is the TCP-like CCID2 (RFC 4341). Additional CCIDs, such as
25 the TCP-friendly CCID3 (RFC 4342), are optional.
31 DCCP is a Proposed Standard (RFC 2026), and the homepage for DCCP as a protocol
37 The Linux DCCP implementation does not currently support all the features that are
43 For more up-to-date versions of the DCCP implementation, please consider using
44 the experimental DCCP test tree; instructions for checking this out are on:
50 DCCP_SOCKOPT_QPOLICY_ID sets the dequeuing policy for outgoing packets. It takes
51 a policy ID as argument and can only be set before the connection (i.e. changes
53 defined: the "simple" policy (DCCPQ_POLICY_SIMPLE), which does nothing special,
62 DCCP_SOCKOPT_QPOLICY_TXQLEN sets the maximum length of the output queue. A zero
64 the interpretation of this parameter depends on the current dequeuing policy
65 (see above): the "simple" policy will enforce a fixed queue size by returning
66 EAGAIN, whereas the "prio" policy enforces a fixed queue length by dropping the
70 DCCP_SOCKOPT_SERVICE sets the service. The specification mandates use of
72 the socket will fall back to 0 (which means that no meaningful service code
78 DCCP_SOCKOPT_GET_CUR_MPS is read-only and retrieves the current maximum packet
81 DCCP_SOCKOPT_AVAILABLE_CCIDS is also read-only and returns the list of CCIDs
82 supported by the endpoint. The option value is an array of type uint8_t whose
83 size is passed as option length. The minimum array size is 4 elements, the
84 value returned in the optlen argument always reflects the true number of
87 DCCP_SOCKOPT_CCID is write-only and sets both the TX and RX CCIDs at the same
88 time, combining the operation of the next two socket options. This option is
89 preferable over the latter two, since often applications will use the same
93 must be registered on the socket before calling connect() or listen().
95 DCCP_SOCKOPT_TX_CCID is read/write. It returns the current CCID (if set) or sets
96 the preference list for the TX CCID, using the same format as DCCP_SOCKOPT_CCID.
97 Please note that the getsockopt argument type here is `int', not uint8_t.
99 DCCP_SOCKOPT_RX_CCID is analogous to DCCP_SOCKOPT_TX_CCID, but for the RX CCID.
101 DCCP_SOCKOPT_SERVER_TIMEWAIT enables the server (listening socket) to hold
102 timewait state when closing the connection (RFC 4340, 8.3). The usual case is
103 that the closing server sends a CloseReq, whereupon the client holds timewait
104 state. When this boolean socket option is on, the server sends a Close instead
107 DCCP_SOCKOPT_SEND_CSCOV and DCCP_SOCKOPT_RECV_CSCOV are used for setting the
109 always cover the entire packet and that only fully covered application data is
110 accepted by the receiver. Hence, when using this feature on the sender, it must
111 be enabled at the receiver, too with suitable choice of CsCov.
113 DCCP_SOCKOPT_SEND_CSCOV sets the sender checksum coverage. Values in the
116 DCCP_SOCKOPT_RECV_CSCOV is for the receiver and has a different meaning: it
119 Values in the range 1..15 indicate that packets with minimally such a
120 coverage value are also acceptable. The higher the number, the more
122 settings are inherited to the child socket after accept().
127 Returns a `struct tfrc_rx_info' in optval; the buffer for optval and
130 Returns a `struct tfrc_tx_info' in optval; the buffer for optval and
133 On unidirectional connections it is useful to close the unused half-connection
139 Several DCCP default parameters can be managed by the following sysctls
143 The number of active connection initiation retries (the number of
145 the behaviour of the other, passive side: this variable also sets
146 the number of times DCCP repeats sending a Response when the initial
148 is received after the initial Request). This value should be greater
152 How often a DCCP Response is retransmitted until the listening DCCP
161 Default CCID for the sender-receiver half-connection. Depending on the
162 choice of CCID, the Send Ack Vector feature is enabled automatically.
165 Default CCID for the receiver-sender half-connection; see tx_ccid.
168 The initial sequence window (sec. 7.5.2) of the sender. This influences
169 the local ackno validity and the remote seqno validity windows (7.5.1).
170 Values in the range Wmin = 32 (RFC 4340, 7.5.2) up to 2^32-1 can be set.
173 The size of the transmit buffer in packets. A value of 0 corresponds
178 sequence-invalid packets on the same socket (RFC 4340, 7.5.4). The unit
185 Works as in udp(7): returns in the `int' argument pointer the size of
186 the next pending datagram in bytes, or 0 when no datagram is pending.
192 CCID-2 supports the RTAX_RTO_MIN per-route setting for the minimum value
193 of the RTO timer. This setting can be modified via the 'rto_min' option
198 CCID-3 also supports the rto_min setting: it is used to define the lower
199 bound for the expiry of the nofeedback timer. This can be useful on LANs
206 because the checksum covers the pseudo-header as per TCP and UDP. Linux NAT