6fdd34d43b
This removes the use of the sysctl and the minisock variable for the Send Ack
Vector feature, as it now is handled fully dynamically via feature negotiation
(i.e. when CCID-2 is enabled, Ack Vectors are automatically enabled as per
RFC 4341, 4.).
Using a sysctl in parallel to this implementation would open the door to
crashes, since much of the code relies on tests of the boolean minisock /
sysctl variable. Thus, this patch replaces all tests of type
if (dccp_msk(sk)->dccpms_send_ack_vector)
/* ... */
with
if (dp->dccps_hc_rx_ackvec != NULL)
/* ... */
The dccps_hc_rx_ackvec is allocated by the dccp_hdlr_ackvec() when feature
negotiation concluded that Ack Vectors are to be used on the half-connection.
Otherwise, it is NULL (due to dccp_init_sock/dccp_create_openreq_child),
so that the test is a valid one.
The activation handler for Ack Vectors is called as soon as the feature
negotiation has concluded at the
* server when the Ack marking the transition RESPOND => OPEN arrives;
* client after it has sent its ACK, marking the transition REQUEST => PARTOPEN.
Adding the sequence number of the Response packet to the Ack Vector has been
removed, since
(a) connection establishment implies that the Response has been received;
(b) the CCIDs only look at packets received in the (PART)OPEN state, i.e.
this entry will always be ignored;
(c) it can not be used for anything useful - to detect loss for instance, only
packets received after the loss can serve as pseudo-dupacks.
There was a FIXME to change the error code when dccp_ackvec_add() fails.
I removed this after finding out that:
* the check whether ackno < ISN is already made earlier,
* this Response is likely the 1st packet with an Ackno that the client gets,
* so when dccp_ackvec_add() fails, the reason is likely not a packet error.
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>
72 lines
1.8 KiB
C
72 lines
1.8 KiB
C
/*
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* net/dccp/diag.c
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*
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* An implementation of the DCCP protocol
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* Arnaldo Carvalho de Melo <acme@mandriva.com>
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/module.h>
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#include <linux/inet_diag.h>
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#include "ccid.h"
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#include "dccp.h"
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static void dccp_get_info(struct sock *sk, struct tcp_info *info)
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{
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struct dccp_sock *dp = dccp_sk(sk);
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const struct inet_connection_sock *icsk = inet_csk(sk);
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memset(info, 0, sizeof(*info));
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info->tcpi_state = sk->sk_state;
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info->tcpi_retransmits = icsk->icsk_retransmits;
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info->tcpi_probes = icsk->icsk_probes_out;
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info->tcpi_backoff = icsk->icsk_backoff;
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info->tcpi_pmtu = icsk->icsk_pmtu_cookie;
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if (dp->dccps_hc_rx_ackvec != NULL)
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info->tcpi_options |= TCPI_OPT_SACK;
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ccid_hc_rx_get_info(dp->dccps_hc_rx_ccid, sk, info);
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ccid_hc_tx_get_info(dp->dccps_hc_tx_ccid, sk, info);
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}
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static void dccp_diag_get_info(struct sock *sk, struct inet_diag_msg *r,
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void *_info)
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{
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r->idiag_rqueue = r->idiag_wqueue = 0;
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if (_info != NULL)
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dccp_get_info(sk, _info);
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}
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static const struct inet_diag_handler dccp_diag_handler = {
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.idiag_hashinfo = &dccp_hashinfo,
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.idiag_get_info = dccp_diag_get_info,
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.idiag_type = DCCPDIAG_GETSOCK,
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.idiag_info_size = sizeof(struct tcp_info),
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};
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static int __init dccp_diag_init(void)
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{
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return inet_diag_register(&dccp_diag_handler);
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}
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static void __exit dccp_diag_fini(void)
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{
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inet_diag_unregister(&dccp_diag_handler);
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}
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module_init(dccp_diag_init);
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module_exit(dccp_diag_fini);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Arnaldo Carvalho de Melo <acme@mandriva.com>");
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MODULE_DESCRIPTION("DCCP inet_diag handler");
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MODULE_ALIAS_NET_PF_PROTO_TYPE(PF_NETLINK, NETLINK_INET_DIAG, DCCPDIAG_GETSOCK);
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