// 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 Intel Corp. * Copyright (c) 2001 Nokia, Inc. * Copyright (c) 2001 La Monte H.P. Yarroll * * This abstraction carries sctp events to the ULP (sockets). * * Please send any bug reports or fixes you make to the * email address(es): * lksctp developers <[email protected]> * * Written or modified by: * Jon Grimm <[email protected]> * La Monte H.P. Yarroll <[email protected]> * Sridhar Samudrala <[email protected]> */ #include <linux/slab.h> #include <linux/types.h> #include <linux/skbuff.h> #include <net/sock.h> #include <net/busy_poll.h> #include <net/sctp/structs.h> #include <net/sctp/sctp.h> #include <net/sctp/sm.h> /* Forward declarations for internal helpers. */ static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq, struct sctp_ulpevent *); static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *, struct sctp_ulpevent *); static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq); /* 1st Level Abstractions */ /* Initialize a ULP queue from a block of memory. */ void sctp_ulpq_init(struct sctp_ulpq *ulpq, struct sctp_association *asoc) { … } /* Flush the reassembly and ordering queues. */ void sctp_ulpq_flush(struct sctp_ulpq *ulpq) { … } /* Dispose of a ulpqueue. */ void sctp_ulpq_free(struct sctp_ulpq *ulpq) { … } /* Process an incoming DATA chunk. */ int sctp_ulpq_tail_data(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, gfp_t gfp) { … } /* Add a new event for propagation to the ULP. */ /* Clear the partial delivery mode for this socket. Note: This * assumes that no association is currently in partial delivery mode. */ int sctp_clear_pd(struct sock *sk, struct sctp_association *asoc) { … } /* Set the pd_mode on the socket and ulpq */ static void sctp_ulpq_set_pd(struct sctp_ulpq *ulpq) { … } /* Clear the pd_mode and restart any pending messages waiting for delivery. */ static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq) { … } int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sk_buff_head *skb_list) { … } /* 2nd Level Abstractions */ /* Helper function to store chunks that need to be reassembled. */ static void sctp_ulpq_store_reasm(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event) { … } /* Helper function to return an event corresponding to the reassembled * datagram. * This routine creates a re-assembled skb given the first and last skb's * as stored in the reassembly queue. The skb's may be non-linear if the sctp * payload was fragmented on the way and ip had to reassemble them. * We add the rest of skb's to the first skb's fraglist. */ struct sctp_ulpevent *sctp_make_reassembled_event(struct net *net, struct sk_buff_head *queue, struct sk_buff *f_frag, struct sk_buff *l_frag) { … } /* Helper function to check if an incoming chunk has filled up the last * missing fragment in a SCTP datagram and return the corresponding event. */ static struct sctp_ulpevent *sctp_ulpq_retrieve_reassembled(struct sctp_ulpq *ulpq) { … } /* Retrieve the next set of fragments of a partial message. */ static struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq) { … } /* Helper function to reassemble chunks. Hold chunks on the reasm queue that * need reassembling. */ static struct sctp_ulpevent *sctp_ulpq_reasm(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event) { … } /* Retrieve the first part (sequential fragments) for partial delivery. */ static struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq) { … } /* * Flush out stale fragments from the reassembly queue when processing * a Forward TSN. * * RFC 3758, Section 3.6 * * After receiving and processing a FORWARD TSN, the data receiver MUST * take cautions in updating its re-assembly queue. The receiver MUST * remove any partially reassembled message, which is still missing one * or more TSNs earlier than or equal to the new cumulative TSN point. * In the event that the receiver has invoked the partial delivery API, * a notification SHOULD also be generated to inform the upper layer API * that the message being partially delivered will NOT be completed. */ void sctp_ulpq_reasm_flushtsn(struct sctp_ulpq *ulpq, __u32 fwd_tsn) { … } /* * Drain the reassembly queue. If we just cleared parted delivery, it * is possible that the reassembly queue will contain already reassembled * messages. Retrieve any such messages and give them to the user. */ static void sctp_ulpq_reasm_drain(struct sctp_ulpq *ulpq) { … } /* Helper function to gather skbs that have possibly become * ordered by an incoming chunk. */ static void sctp_ulpq_retrieve_ordered(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event) { … } /* Helper function to store chunks needing ordering. */ static void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event) { … } static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq, struct sctp_ulpevent *event) { … } /* Helper function to gather skbs that have possibly become * ordered by forward tsn skipping their dependencies. */ static void sctp_ulpq_reap_ordered(struct sctp_ulpq *ulpq, __u16 sid) { … } /* Skip over an SSN. This is used during the processing of * Forwared TSN chunk to skip over the abandoned ordered data */ void sctp_ulpq_skip(struct sctp_ulpq *ulpq, __u16 sid, __u16 ssn) { … } __u16 sctp_ulpq_renege_list(struct sctp_ulpq *ulpq, struct sk_buff_head *list, __u16 needed) { … } /* Renege 'needed' bytes from the ordering queue. */ static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed) { … } /* Renege 'needed' bytes from the reassembly queue. */ static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed) { … } /* Partial deliver the first message as there is pressure on rwnd. */ void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq, gfp_t gfp) { … } /* Renege some packets to make room for an incoming chunk. */ void sctp_ulpq_renege(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, gfp_t gfp) { … } /* Notify the application if an association is aborted and in * partial delivery mode. Send up any pending received messages. */ void sctp_ulpq_abort_pd(struct sctp_ulpq *ulpq, gfp_t gfp) { … }
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