// SPDX-License-Identifier: GPL-2.0-or-later /* SCTP kernel implementation * (C) Copyright IBM Corp. 2001, 2004 * Copyright (c) 1999-2000 Cisco, Inc. * Copyright (c) 1999-2001 Motorola, Inc. * Copyright (c) 2001-2003 Intel Corp. * * This file is part of the SCTP kernel implementation * * These functions implement the sctp_outq class. The outqueue handles * bundling and queueing of outgoing SCTP chunks. * * Please send any bug reports or fixes you make to the * email address(es): * lksctp developers <[email protected]> * * Written or modified by: * La Monte H.P. Yarroll <[email protected]> * Karl Knutson <[email protected]> * Perry Melange <[email protected]> * Xingang Guo <[email protected]> * Hui Huang <[email protected]> * Sridhar Samudrala <[email protected]> * Jon Grimm <[email protected]> */ #define pr_fmt(fmt) … #include <linux/types.h> #include <linux/list.h> /* For struct list_head */ #include <linux/socket.h> #include <linux/ip.h> #include <linux/slab.h> #include <net/sock.h> /* For skb_set_owner_w */ #include <net/sctp/sctp.h> #include <net/sctp/sm.h> #include <net/sctp/stream_sched.h> #include <trace/events/sctp.h> /* Declare internal functions here. */ static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn); static void sctp_check_transmitted(struct sctp_outq *q, struct list_head *transmitted_queue, struct sctp_transport *transport, union sctp_addr *saddr, struct sctp_sackhdr *sack, __u32 *highest_new_tsn); static void sctp_mark_missing(struct sctp_outq *q, struct list_head *transmitted_queue, struct sctp_transport *transport, __u32 highest_new_tsn, int count_of_newacks); static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp); /* Add data to the front of the queue. */ static inline void sctp_outq_head_data(struct sctp_outq *q, struct sctp_chunk *ch) { … } /* Take data from the front of the queue. */ static inline struct sctp_chunk *sctp_outq_dequeue_data(struct sctp_outq *q) { … } /* Add data chunk to the end of the queue. */ static inline void sctp_outq_tail_data(struct sctp_outq *q, struct sctp_chunk *ch) { … } /* * SFR-CACC algorithm: * D) If count_of_newacks is greater than or equal to 2 * and t was not sent to the current primary then the * sender MUST NOT increment missing report count for t. */ static inline int sctp_cacc_skip_3_1_d(struct sctp_transport *primary, struct sctp_transport *transport, int count_of_newacks) { … } /* * SFR-CACC algorithm: * F) If count_of_newacks is less than 2, let d be the * destination to which t was sent. If cacc_saw_newack * is 0 for destination d, then the sender MUST NOT * increment missing report count for t. */ static inline int sctp_cacc_skip_3_1_f(struct sctp_transport *transport, int count_of_newacks) { … } /* * SFR-CACC algorithm: * 3.1) If CYCLING_CHANGEOVER is 0, the sender SHOULD * execute steps C, D, F. * * C has been implemented in sctp_outq_sack */ static inline int sctp_cacc_skip_3_1(struct sctp_transport *primary, struct sctp_transport *transport, int count_of_newacks) { … } /* * SFR-CACC algorithm: * 3.2) Else if CYCLING_CHANGEOVER is 1, and t is less * than next_tsn_at_change of the current primary, then * the sender MUST NOT increment missing report count * for t. */ static inline int sctp_cacc_skip_3_2(struct sctp_transport *primary, __u32 tsn) { … } /* * SFR-CACC algorithm: * 3) If the missing report count for TSN t is to be * incremented according to [RFC2960] and * [SCTP_STEWART-2002], and CHANGEOVER_ACTIVE is set, * then the sender MUST further execute steps 3.1 and * 3.2 to determine if the missing report count for * TSN t SHOULD NOT be incremented. * * 3.3) If 3.1 and 3.2 do not dictate that the missing * report count for t should not be incremented, then * the sender SHOULD increment missing report count for * t (according to [RFC2960] and [SCTP_STEWART_2002]). */ static inline int sctp_cacc_skip(struct sctp_transport *primary, struct sctp_transport *transport, int count_of_newacks, __u32 tsn) { … } /* Initialize an existing sctp_outq. This does the boring stuff. * You still need to define handlers if you really want to DO * something with this structure... */ void sctp_outq_init(struct sctp_association *asoc, struct sctp_outq *q) { … } /* Free the outqueue structure and any related pending chunks. */ static void __sctp_outq_teardown(struct sctp_outq *q) { … } void sctp_outq_teardown(struct sctp_outq *q) { … } /* Free the outqueue structure and any related pending chunks. */ void sctp_outq_free(struct sctp_outq *q) { … } /* Put a new chunk in an sctp_outq. */ void sctp_outq_tail(struct sctp_outq *q, struct sctp_chunk *chunk, gfp_t gfp) { … } /* Insert a chunk into the sorted list based on the TSNs. The retransmit list * and the abandoned list are in ascending order. */ static void sctp_insert_list(struct list_head *head, struct list_head *new) { … } static int sctp_prsctp_prune_sent(struct sctp_association *asoc, struct sctp_sndrcvinfo *sinfo, struct list_head *queue, int msg_len) { … } static int sctp_prsctp_prune_unsent(struct sctp_association *asoc, struct sctp_sndrcvinfo *sinfo, int msg_len) { … } /* Abandon the chunks according their priorities */ void sctp_prsctp_prune(struct sctp_association *asoc, struct sctp_sndrcvinfo *sinfo, int msg_len) { … } /* Mark all the eligible packets on a transport for retransmission. */ void sctp_retransmit_mark(struct sctp_outq *q, struct sctp_transport *transport, __u8 reason) { … } /* Mark all the eligible packets on a transport for retransmission and force * one packet out. */ void sctp_retransmit(struct sctp_outq *q, struct sctp_transport *transport, enum sctp_retransmit_reason reason) { … } /* * Transmit DATA chunks on the retransmit queue. Upon return from * __sctp_outq_flush_rtx() the packet 'pkt' may contain chunks which * need to be transmitted by the caller. * We assume that pkt->transport has already been set. * * The return value is a normal kernel error return value. */ static int __sctp_outq_flush_rtx(struct sctp_outq *q, struct sctp_packet *pkt, int rtx_timeout, int *start_timer, gfp_t gfp) { … } /* Cork the outqueue so queued chunks are really queued. */ void sctp_outq_uncork(struct sctp_outq *q, gfp_t gfp) { … } static int sctp_packet_singleton(struct sctp_transport *transport, struct sctp_chunk *chunk, gfp_t gfp) { … } /* Struct to hold the context during sctp outq flush */ struct sctp_flush_ctx { … }; /* transport: current transport */ static void sctp_outq_select_transport(struct sctp_flush_ctx *ctx, struct sctp_chunk *chunk) { … } static void sctp_outq_flush_ctrl(struct sctp_flush_ctx *ctx) { … } /* Returns false if new data shouldn't be sent */ static bool sctp_outq_flush_rtx(struct sctp_flush_ctx *ctx, int rtx_timeout) { … } static void sctp_outq_flush_data(struct sctp_flush_ctx *ctx, int rtx_timeout) { … } static void sctp_outq_flush_transports(struct sctp_flush_ctx *ctx) { … } /* Try to flush an outqueue. * * Description: Send everything in q which we legally can, subject to * congestion limitations. * * Note: This function can be called from multiple contexts so appropriate * locking concerns must be made. Today we use the sock lock to protect * this function. */ static void sctp_outq_flush(struct sctp_outq *q, int rtx_timeout, gfp_t gfp) { … } /* Update unack_data based on the incoming SACK chunk */ static void sctp_sack_update_unack_data(struct sctp_association *assoc, struct sctp_sackhdr *sack) { … } /* This is where we REALLY process a SACK. * * Process the SACK against the outqueue. Mostly, this just frees * things off the transmitted queue. */ int sctp_outq_sack(struct sctp_outq *q, struct sctp_chunk *chunk) { … } /* Is the outqueue empty? * The queue is empty when we have not pending data, no in-flight data * and nothing pending retransmissions. */ int sctp_outq_is_empty(const struct sctp_outq *q) { … } /******************************************************************** * 2nd Level Abstractions ********************************************************************/ /* Go through a transport's transmitted list or the association's retransmit * list and move chunks that are acked by the Cumulative TSN Ack to q->sacked. * The retransmit list will not have an associated transport. * * I added coherent debug information output. --xguo * * Instead of printing 'sacked' or 'kept' for each TSN on the * transmitted_queue, we print a range: SACKED: TSN1-TSN2, TSN3, TSN4-TSN5. * KEPT TSN6-TSN7, etc. */ static void sctp_check_transmitted(struct sctp_outq *q, struct list_head *transmitted_queue, struct sctp_transport *transport, union sctp_addr *saddr, struct sctp_sackhdr *sack, __u32 *highest_new_tsn_in_sack) { … } /* Mark chunks as missing and consequently may get retransmitted. */ static void sctp_mark_missing(struct sctp_outq *q, struct list_head *transmitted_queue, struct sctp_transport *transport, __u32 highest_new_tsn_in_sack, int count_of_newacks) { … } /* Is the given TSN acked by this packet? */ static int sctp_acked(struct sctp_sackhdr *sack, __u32 tsn) { … } static inline int sctp_get_skip_pos(struct sctp_fwdtsn_skip *skiplist, int nskips, __be16 stream) { … } /* Create and add a fwdtsn chunk to the outq's control queue if needed. */ void sctp_generate_fwdtsn(struct sctp_outq *q, __u32 ctsn) { … }
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