From 22098763a10d9c1340827fcf6edab66f153b27f0 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 13 Sep 2026 12:27:00 -0700 Subject: Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Don't destroy user event fields when removal fails User event fields are destroyed before the event is removed from visibility. But that can fail leaving the still visible event with no fields. Move the destroying of the fields to after the event is successfully removed from visibility. - Initialize function graph state is fork before calling copy_exec_state() For non-CLONE_VM forks, copy_exec_state() allocates a new task_exec_state. If that allocation fails, ftrace_graph_exit_task() will free the tasks ret_stack pointer. Since that pointer is still using the parent's ret_stack, it mistakenly frees the parent's pointer too. Call ftrace_graph_init() on the task first which will NULL out the new tasks's ret_stack and if the copy fails, it will not free anything. - Remove FGRAPH_MAX_INDEX The macro FGRAPH_MAX_INDEX was added but never used. Remove it. - Save ent_size in function graph printing of nested functions The function graph tracer needs to look at the next event to see if the next event is the return of the current function entry. If it is, it prints a single line: ktime_get(); Otherwise it prints it like a nested function: tick_nohz_irq_exit() { ktime_get(); kcpustat_irq_exit(); } In order to look at the next event, it must save the current event so that it has the information to print from it. It saves the event in the iterator descriptor called "ent". What it doesn't save is the ent_size of the event which is now used to know if the function graph arguments are to be printed. The peek doesn't save the size so the size used happens to be that of the size of the last event that was seen. Save the entry event size in the iterator descriptor so that the correct size is used. - Fix several errors with freeing data in the histogram code The histogram code had a lot of leaked or or incorrect accounting when failures happen. Correct them. - Fix histogram regression of .percent and .graph modifiers Up until 6.3 histogram values could have "percent" or "graph" modifiers that changed how they were printed. But a change that added restricting histograms values from being strings, stack traces and other modifiers inadvertently prevented them from using the percent and graph modifiers, which were legal use cases for values. Put back the percent and graph modifiers. - Fix various typos in the comments - Set the trace_clock before initializing a histogram with clock argument The histogram API allows the user to specific which trace clock to use via a "clock=" string. The histogram is set up first before the clock is checked. If the passed in clock is not valid, it exits without fully fixing up the histogram leaving it on the list and a use-after-free can trigger. Update the clock argument first and if it fails then exit gracefully before the histogram trigger is placed on any lists. - Restore :mod: trailer after parsing in ftrace_set_clr_event The function ftrace_set_clr_event() modifies the parse string and needs to put it back to what was passed in. It searches for ":mod:" via a strsep() but fails to put back the first ':' in the string. Add back the ':' in the passed in string. - Take trace_array reference when opening a tracer options file The options files are dynamically created and some tracers add their own options. When a tracer adds their own list of options, the trace_array holding them has an array to hold the list of options for each tracer. This array increases in size via a krealloc(), and the new entry gets a newly allocated array to hold the options of the new tracer being added. The element in each entry of the tracer's option array holds a pointer back to the trace_array, a pointer to the tracer it is associated to, a pointer to the flags of the option. The issue is that these arrays are freed when the trace_array is freed when its instance it represents is removed from the instances directory. There's a race that an open of one of these options files can happen when the instance is being removed. Add a new helper function to be called by the open function of the options file to iterate all existing trace_arrays under a lock and find the one that has the given option element in one of it's tracer arrays. If found, then update the associated trace_array's reference counter to keep it from being freed. If not found, have the open call return -ENODEV. - Disable interrupts when acquiring the lock in rb_wake_up_waiters() The function rb_wake_up_waiters() assumes it will be called in interrupt context and does not disable irqs when taking cpu_buffer->reader_lock, which can be called in hard interrupt context. The issue is in PREEMPT_RT, this function is called in thread context leaving this lock open to a deadlock. Take the lock with interrupts disabled. - Use rcu_assign_pointer() for tmp_ops filter hash The tmp_ops used in update_ftrace_direct_mod() assigns its filter_hash field directly, but that field is annotated as __rcu and sparse complains. Assign it with rcu_assign_pointer() - Fix use-after-free in enable_trigger_private_data_free() The trace_event_call is accessed through the event_trigger_data's trace_event_file pointer to put the trace_event_call on freeing. The issue is that the trace_event_file data may have been freed already causing a use-after-free. Add a field to the event_trigger_data that points directly to the trace_event_call so that it can decrement its reference directly without needing to go through the trace_event_file. - Fix accounting of buffer data remote headers trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the number of pages is needed for the asked for size as it doesn't take into account the meta data on each page. Add a helper function to do the calculation properly and use that in these functions. - Catch nr_page_va overflow in ring_buffer_desc sizing The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for. - Do not resize the subbuf order if any per_cpu buffer is disabled The mmapping of ring buffers disables resizing the subbuffers, but it is done per-cpu whereas the subbuf size change is done for all the per_cpu buffers under the buffer->mutex. It could change the size of some while the mapping is happening on others. Have the resize of the subbuf order check all the per_cpu buffers under the lock to see if any of them is disabled before starting and causing an inconsistency between buffers that are being mapped. * tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits) ring-buffer: Check resize_disabled before publishing the new subbuf order tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing tracing/remotes: Account for ring buffer page header in size calculation tracing: Don't dereference trace_event_file in deferred trigger free ftrace: Use rcu_assign_pointer() for tmp_ops filter hash ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters() tracing: Take trace_array reference when opening a tracer options file tracing: Fix ring_buffer_read_page_size() kernel-doc tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event() tracing: Fix memory corruption from a "STACKTRACE" histogram key tracing: Fix memory corruption from the histogram stacktrace modifier tracing: Undo the registration when enabling the histogram trigger fails tracing: Take the reference before publishing the named histogram trigger tracing: Set the trace clock before registering the histogram trigger tracing: Fix typo "preceeded" in comment tracing: Fix typo "availabe" in comment tracing: Let histogram values keep the percent and graph modifiers tracing: Keep the entry count when the histogram stats allocation fails tracing: Free histogram the field rejected for a bad modifier tracing: Free histogram the var ref when its initialization fails ... --- net/sctp/ulpqueue.c | 1126 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 1126 insertions(+) create mode 100644 net/sctp/ulpqueue.c (limited to 'net/sctp/ulpqueue.c') diff --git a/net/sctp/ulpqueue.c b/net/sctp/ulpqueue.c new file mode 100644 index 000000000..b05daafd3 --- /dev/null +++ b/net/sctp/ulpqueue.c @@ -0,0 +1,1126 @@ +// 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 + * + * Written or modified by: + * Jon Grimm + * La Monte H.P. Yarroll + * Sridhar Samudrala + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +/* 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) +{ + memset(ulpq, 0, sizeof(struct sctp_ulpq)); + + ulpq->asoc = asoc; + skb_queue_head_init(&ulpq->reasm); + skb_queue_head_init(&ulpq->reasm_uo); + skb_queue_head_init(&ulpq->lobby); + ulpq->pd_mode = 0; +} + + +/* Flush the reassembly and ordering queues. */ +void sctp_ulpq_flush(struct sctp_ulpq *ulpq) +{ + struct sk_buff *skb; + struct sctp_ulpevent *event; + + while ((skb = __skb_dequeue(&ulpq->lobby)) != NULL) { + event = sctp_skb2event(skb); + sctp_ulpevent_free(event); + } + + while ((skb = __skb_dequeue(&ulpq->reasm)) != NULL) { + event = sctp_skb2event(skb); + sctp_ulpevent_free(event); + } + + while ((skb = __skb_dequeue(&ulpq->reasm_uo)) != NULL) { + event = sctp_skb2event(skb); + sctp_ulpevent_free(event); + } +} + +/* Dispose of a ulpqueue. */ +void sctp_ulpq_free(struct sctp_ulpq *ulpq) +{ + sctp_ulpq_flush(ulpq); +} + +/* Process an incoming DATA chunk. */ +int sctp_ulpq_tail_data(struct sctp_ulpq *ulpq, struct sctp_chunk *chunk, + gfp_t gfp) +{ + struct sk_buff_head temp; + struct sctp_ulpevent *event; + int event_eor = 0; + + /* Create an event from the incoming chunk. */ + event = sctp_ulpevent_make_rcvmsg(chunk->asoc, chunk, gfp); + if (!event) + return -ENOMEM; + + event->ssn = ntohs(chunk->subh.data_hdr->ssn); + event->ppid = chunk->subh.data_hdr->ppid; + + /* Do reassembly if needed. */ + event = sctp_ulpq_reasm(ulpq, event); + + /* Do ordering if needed. */ + if (event) { + /* Create a temporary list to collect chunks on. */ + skb_queue_head_init(&temp); + __skb_queue_tail(&temp, sctp_event2skb(event)); + + if (event->msg_flags & MSG_EOR) + event = sctp_ulpq_order(ulpq, event); + } + + /* Send event to the ULP. 'event' is the sctp_ulpevent for + * very first SKB on the 'temp' list. + */ + if (event) { + event_eor = (event->msg_flags & MSG_EOR) ? 1 : 0; + sctp_ulpq_tail_event(ulpq, &temp); + } + + return event_eor; +} + +/* 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) +{ + struct sctp_sock *sp = sctp_sk(sk); + + if (atomic_dec_and_test(&sp->pd_mode)) { + /* This means there are no other associations in PD, so + * we can go ahead and clear out the lobby in one shot + */ + if (!skb_queue_empty(&sp->pd_lobby)) { + skb_queue_splice_tail_init(&sp->pd_lobby, + &sk->sk_receive_queue); + return 1; + } + } else { + /* There are other associations in PD, so we only need to + * pull stuff out of the lobby that belongs to the + * associations that is exiting PD (all of its notifications + * are posted here). + */ + if (!skb_queue_empty(&sp->pd_lobby) && asoc) { + struct sk_buff *skb, *tmp; + struct sctp_ulpevent *event; + + sctp_skb_for_each(skb, &sp->pd_lobby, tmp) { + event = sctp_skb2event(skb); + if (event->asoc == asoc) { + __skb_unlink(skb, &sp->pd_lobby); + __skb_queue_tail(&sk->sk_receive_queue, + skb); + } + } + } + } + + return 0; +} + +/* Set the pd_mode on the socket and ulpq */ +static void sctp_ulpq_set_pd(struct sctp_ulpq *ulpq) +{ + struct sctp_sock *sp = sctp_sk(ulpq->asoc->base.sk); + + atomic_inc(&sp->pd_mode); + ulpq->pd_mode = 1; +} + +/* Clear the pd_mode and restart any pending messages waiting for delivery. */ +static int sctp_ulpq_clear_pd(struct sctp_ulpq *ulpq) +{ + ulpq->pd_mode = 0; + sctp_ulpq_reasm_drain(ulpq); + return sctp_clear_pd(ulpq->asoc->base.sk, ulpq->asoc); +} + +int sctp_ulpq_tail_event(struct sctp_ulpq *ulpq, struct sk_buff_head *skb_list) +{ + struct sock *sk = ulpq->asoc->base.sk; + struct sctp_sock *sp = sctp_sk(sk); + struct sctp_ulpevent *event; + struct sk_buff_head *queue; + struct sk_buff *skb; + int clear_pd = 0; + + skb = __skb_peek(skb_list); + event = sctp_skb2event(skb); + + /* If the socket is just going to throw this away, do not + * even try to deliver it. + */ + if (sk->sk_shutdown & RCV_SHUTDOWN && + (sk->sk_shutdown & SEND_SHUTDOWN || + !sctp_ulpevent_is_notification(event))) + goto out_free; + + if (!sctp_ulpevent_is_notification(event)) { + sk_mark_napi_id(sk, skb); + sk_incoming_cpu_update(sk); + } + /* Check if the user wishes to receive this event. */ + if (!sctp_ulpevent_is_enabled(event, ulpq->asoc->subscribe)) + goto out_free; + + /* If we are in partial delivery mode, post to the lobby until + * partial delivery is cleared, unless, of course _this_ is + * the association the cause of the partial delivery. + */ + + if (atomic_read(&sp->pd_mode) == 0) { + queue = &sk->sk_receive_queue; + } else { + if (ulpq->pd_mode) { + /* If the association is in partial delivery, we + * need to finish delivering the partially processed + * packet before passing any other data. This is + * because we don't truly support stream interleaving. + */ + if ((event->msg_flags & MSG_NOTIFICATION) || + (SCTP_DATA_NOT_FRAG == + (event->msg_flags & SCTP_DATA_FRAG_MASK))) + queue = &sp->pd_lobby; + else { + clear_pd = event->msg_flags & MSG_EOR; + queue = &sk->sk_receive_queue; + } + } else { + /* + * If fragment interleave is enabled, we + * can queue this to the receive queue instead + * of the lobby. + */ + if (sp->frag_interleave) + queue = &sk->sk_receive_queue; + else + queue = &sp->pd_lobby; + } + } + + skb_queue_splice_tail_init(skb_list, queue); + + /* Did we just complete partial delivery and need to get + * rolling again? Move pending data to the receive + * queue. + */ + if (clear_pd) + sctp_ulpq_clear_pd(ulpq); + + if (queue == &sk->sk_receive_queue && !sp->data_ready_signalled) { + if (!sock_owned_by_user(sk)) + sp->data_ready_signalled = 1; + sk->sk_data_ready(sk); + } + return 1; + +out_free: + sctp_queue_purge_ulpevents(skb_list); + + return 0; +} + +/* 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) +{ + struct sk_buff *pos; + struct sctp_ulpevent *cevent; + __u32 tsn, ctsn; + + tsn = event->tsn; + + /* See if it belongs at the end. */ + pos = skb_peek_tail(&ulpq->reasm); + if (!pos) { + __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); + return; + } + + /* Short circuit just dropping it at the end. */ + cevent = sctp_skb2event(pos); + ctsn = cevent->tsn; + if (TSN_lt(ctsn, tsn)) { + __skb_queue_tail(&ulpq->reasm, sctp_event2skb(event)); + return; + } + + /* Find the right place in this list. We store them by TSN. */ + skb_queue_walk(&ulpq->reasm, pos) { + cevent = sctp_skb2event(pos); + ctsn = cevent->tsn; + + if (TSN_lt(tsn, ctsn)) + break; + } + + /* Insert before pos. */ + __skb_queue_before(&ulpq->reasm, pos, sctp_event2skb(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) +{ + struct sk_buff *pos; + struct sk_buff *new = NULL; + struct sctp_ulpevent *event; + struct sk_buff *pnext, *last; + struct sk_buff *list = skb_shinfo(f_frag)->frag_list; + + /* Store the pointer to the 2nd skb */ + if (f_frag == l_frag) + pos = NULL; + else + pos = f_frag->next; + + /* Get the last skb in the f_frag's frag_list if present. */ + for (last = list; list; last = list, list = list->next) + ; + + /* Add the list of remaining fragments to the first fragments + * frag_list. + */ + if (last) + last->next = pos; + else { + if (skb_cloned(f_frag)) { + /* This is a cloned skb, we can't just modify + * the frag_list. We need a new skb to do that. + * Instead of calling skb_unshare(), we'll do it + * ourselves since we need to delay the free. + */ + new = skb_copy(f_frag, GFP_ATOMIC); + if (!new) + return NULL; /* try again later */ + + sctp_skb_set_owner_r(new, f_frag->sk); + + skb_shinfo(new)->frag_list = pos; + } else + skb_shinfo(f_frag)->frag_list = pos; + } + + /* Remove the first fragment from the reassembly queue. */ + __skb_unlink(f_frag, queue); + + /* if we did unshare, then free the old skb and re-assign */ + if (new) { + kfree_skb(f_frag); + f_frag = new; + } + + while (pos) { + + pnext = pos->next; + + /* Update the len and data_len fields of the first fragment. */ + f_frag->len += pos->len; + f_frag->data_len += pos->len; + + /* Remove the fragment from the reassembly queue. */ + __skb_unlink(pos, queue); + + /* Break if we have reached the last fragment. */ + if (pos == l_frag) + break; + pos->next = pnext; + pos = pnext; + } + + event = sctp_skb2event(f_frag); + SCTP_INC_STATS(net, SCTP_MIB_REASMUSRMSGS); + + return event; +} + + +/* 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) +{ + struct sk_buff *pos; + struct sctp_ulpevent *cevent; + struct sk_buff *first_frag = NULL; + __u32 ctsn, next_tsn; + struct sctp_ulpevent *retval = NULL; + struct sk_buff *pd_first = NULL; + struct sk_buff *pd_last = NULL; + size_t pd_len = 0; + struct sctp_association *asoc; + u32 pd_point; + + /* Initialized to 0 just to avoid compiler warning message. Will + * never be used with this value. It is referenced only after it + * is set when we find the first fragment of a message. + */ + next_tsn = 0; + + /* The chunks are held in the reasm queue sorted by TSN. + * Walk through the queue sequentially and look for a sequence of + * fragmented chunks that complete a datagram. + * 'first_frag' and next_tsn are reset when we find a chunk which + * is the first fragment of a datagram. Once these 2 fields are set + * we expect to find the remaining middle fragments and the last + * fragment in order. If not, first_frag is reset to NULL and we + * start the next pass when we find another first fragment. + * + * There is a potential to do partial delivery if user sets + * SCTP_PARTIAL_DELIVERY_POINT option. Lets count some things here + * to see if can do PD. + */ + skb_queue_walk(&ulpq->reasm, pos) { + cevent = sctp_skb2event(pos); + ctsn = cevent->tsn; + + switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { + case SCTP_DATA_FIRST_FRAG: + /* If this "FIRST_FRAG" is the first + * element in the queue, then count it towards + * possible PD. + */ + if (skb_queue_is_first(&ulpq->reasm, pos)) { + pd_first = pos; + pd_last = pos; + pd_len = pos->len; + } else { + pd_first = NULL; + pd_last = NULL; + pd_len = 0; + } + + first_frag = pos; + next_tsn = ctsn + 1; + break; + + case SCTP_DATA_MIDDLE_FRAG: + if ((first_frag) && (ctsn == next_tsn)) { + next_tsn++; + if (pd_first) { + pd_last = pos; + pd_len += pos->len; + } + } else + first_frag = NULL; + break; + + case SCTP_DATA_LAST_FRAG: + if (first_frag && (ctsn == next_tsn)) + goto found; + else + first_frag = NULL; + break; + } + } + + asoc = ulpq->asoc; + if (pd_first) { + /* Make sure we can enter partial deliver. + * We can trigger partial delivery only if framgent + * interleave is set, or the socket is not already + * in partial delivery. + */ + if (!sctp_sk(asoc->base.sk)->frag_interleave && + atomic_read(&sctp_sk(asoc->base.sk)->pd_mode)) + goto done; + + cevent = sctp_skb2event(pd_first); + pd_point = sctp_sk(asoc->base.sk)->pd_point; + if (pd_point && pd_point <= pd_len) { + retval = sctp_make_reassembled_event(asoc->base.net, + &ulpq->reasm, + pd_first, pd_last); + if (retval) + sctp_ulpq_set_pd(ulpq); + } + } +done: + return retval; +found: + retval = sctp_make_reassembled_event(ulpq->asoc->base.net, + &ulpq->reasm, first_frag, pos); + if (retval) + retval->msg_flags |= MSG_EOR; + goto done; +} + +/* Retrieve the next set of fragments of a partial message. */ +static struct sctp_ulpevent *sctp_ulpq_retrieve_partial(struct sctp_ulpq *ulpq) +{ + struct sk_buff *pos, *last_frag, *first_frag; + struct sctp_ulpevent *cevent; + __u32 ctsn, next_tsn; + int is_last; + struct sctp_ulpevent *retval; + + /* The chunks are held in the reasm queue sorted by TSN. + * Walk through the queue sequentially and look for the first + * sequence of fragmented chunks. + */ + + if (skb_queue_empty(&ulpq->reasm)) + return NULL; + + last_frag = first_frag = NULL; + retval = NULL; + next_tsn = 0; + is_last = 0; + + skb_queue_walk(&ulpq->reasm, pos) { + cevent = sctp_skb2event(pos); + ctsn = cevent->tsn; + + switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { + case SCTP_DATA_FIRST_FRAG: + if (!first_frag) + return NULL; + goto done; + case SCTP_DATA_MIDDLE_FRAG: + if (!first_frag) { + first_frag = pos; + next_tsn = ctsn + 1; + last_frag = pos; + } else if (next_tsn == ctsn) { + next_tsn++; + last_frag = pos; + } else + goto done; + break; + case SCTP_DATA_LAST_FRAG: + if (!first_frag) + first_frag = pos; + else if (ctsn != next_tsn) + goto done; + last_frag = pos; + is_last = 1; + goto done; + default: + return NULL; + } + } + + /* We have the reassembled event. There is no need to look + * further. + */ +done: + retval = sctp_make_reassembled_event(ulpq->asoc->base.net, &ulpq->reasm, + first_frag, last_frag); + if (retval && is_last) + retval->msg_flags |= MSG_EOR; + + return retval; +} + + +/* 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) +{ + struct sctp_ulpevent *retval = NULL; + + /* Check if this is part of a fragmented message. */ + if (SCTP_DATA_NOT_FRAG == (event->msg_flags & SCTP_DATA_FRAG_MASK)) { + event->msg_flags |= MSG_EOR; + return event; + } + + sctp_ulpq_store_reasm(ulpq, event); + if (!ulpq->pd_mode) + retval = sctp_ulpq_retrieve_reassembled(ulpq); + else { + __u32 ctsn, ctsnap; + + /* Do not even bother unless this is the next tsn to + * be delivered. + */ + ctsn = event->tsn; + ctsnap = sctp_tsnmap_get_ctsn(&ulpq->asoc->peer.tsn_map); + if (TSN_lte(ctsn, ctsnap)) + retval = sctp_ulpq_retrieve_partial(ulpq); + } + + return retval; +} + +/* Retrieve the first part (sequential fragments) for partial delivery. */ +static struct sctp_ulpevent *sctp_ulpq_retrieve_first(struct sctp_ulpq *ulpq) +{ + struct sk_buff *pos, *last_frag, *first_frag; + struct sctp_ulpevent *cevent; + __u32 ctsn, next_tsn; + struct sctp_ulpevent *retval; + + /* The chunks are held in the reasm queue sorted by TSN. + * Walk through the queue sequentially and look for a sequence of + * fragmented chunks that start a datagram. + */ + + if (skb_queue_empty(&ulpq->reasm)) + return NULL; + + last_frag = first_frag = NULL; + retval = NULL; + next_tsn = 0; + + skb_queue_walk(&ulpq->reasm, pos) { + cevent = sctp_skb2event(pos); + ctsn = cevent->tsn; + + switch (cevent->msg_flags & SCTP_DATA_FRAG_MASK) { + case SCTP_DATA_FIRST_FRAG: + if (!first_frag) { + first_frag = pos; + next_tsn = ctsn + 1; + last_frag = pos; + } else + goto done; + break; + + case SCTP_DATA_MIDDLE_FRAG: + if (!first_frag) + return NULL; + if (ctsn == next_tsn) { + next_tsn++; + last_frag = pos; + } else + goto done; + break; + + case SCTP_DATA_LAST_FRAG: + if (!first_frag) + return NULL; + else + goto done; + break; + + default: + return NULL; + } + } + + /* We have the reassembled event. There is no need to look + * further. + */ +done: + retval = sctp_make_reassembled_event(ulpq->asoc->base.net, &ulpq->reasm, + first_frag, last_frag); + return retval; +} + +/* + * 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) +{ + struct sk_buff *pos, *tmp; + struct sctp_ulpevent *event; + __u32 tsn; + + if (skb_queue_empty(&ulpq->reasm)) + return; + + skb_queue_walk_safe(&ulpq->reasm, pos, tmp) { + event = sctp_skb2event(pos); + tsn = event->tsn; + + /* Since the entire message must be abandoned by the + * sender (item A3 in Section 3.5, RFC 3758), we can + * free all fragments on the list that are less then + * or equal to ctsn_point + */ + if (TSN_lte(tsn, fwd_tsn)) { + __skb_unlink(pos, &ulpq->reasm); + sctp_ulpevent_free(event); + } else + break; + } +} + +/* + * 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) +{ + struct sctp_ulpevent *event = NULL; + + if (skb_queue_empty(&ulpq->reasm)) + return; + + while ((event = sctp_ulpq_retrieve_reassembled(ulpq)) != NULL) { + struct sk_buff_head temp; + + skb_queue_head_init(&temp); + __skb_queue_tail(&temp, sctp_event2skb(event)); + + /* Do ordering if needed. */ + if (event->msg_flags & MSG_EOR) + event = sctp_ulpq_order(ulpq, event); + + /* Send event to the ULP. 'event' is the + * sctp_ulpevent for very first SKB on the temp' list. + */ + if (event) + sctp_ulpq_tail_event(ulpq, &temp); + } +} + + +/* 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) +{ + struct sk_buff_head *event_list; + struct sk_buff *pos, *tmp; + struct sctp_ulpevent *cevent; + struct sctp_stream *stream; + __u16 sid, csid, cssn; + + sid = event->stream; + stream = &ulpq->asoc->stream; + + event_list = (struct sk_buff_head *) sctp_event2skb(event)->prev; + + /* We are holding the chunks by stream, by SSN. */ + sctp_skb_for_each(pos, &ulpq->lobby, tmp) { + cevent = (struct sctp_ulpevent *) pos->cb; + csid = cevent->stream; + cssn = cevent->ssn; + + /* Have we gone too far? */ + if (csid > sid) + break; + + /* Have we not gone far enough? */ + if (csid < sid) + continue; + + if (cssn != sctp_ssn_peek(stream, in, sid)) + break; + + /* Found it, so mark in the stream. */ + sctp_ssn_next(stream, in, sid); + + __skb_unlink(pos, &ulpq->lobby); + + /* Attach all gathered skbs to the event. */ + __skb_queue_tail(event_list, pos); + } +} + +/* Helper function to store chunks needing ordering. */ +static void sctp_ulpq_store_ordered(struct sctp_ulpq *ulpq, + struct sctp_ulpevent *event) +{ + struct sk_buff *pos; + struct sctp_ulpevent *cevent; + __u16 sid, csid; + __u16 ssn, cssn; + + pos = skb_peek_tail(&ulpq->lobby); + if (!pos) { + __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); + return; + } + + sid = event->stream; + ssn = event->ssn; + + cevent = (struct sctp_ulpevent *) pos->cb; + csid = cevent->stream; + cssn = cevent->ssn; + if (sid > csid) { + __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); + return; + } + + if ((sid == csid) && SSN_lt(cssn, ssn)) { + __skb_queue_tail(&ulpq->lobby, sctp_event2skb(event)); + return; + } + + /* Find the right place in this list. We store them by + * stream ID and then by SSN. + */ + skb_queue_walk(&ulpq->lobby, pos) { + cevent = (struct sctp_ulpevent *) pos->cb; + csid = cevent->stream; + cssn = cevent->ssn; + + if (csid > sid) + break; + if (csid == sid && SSN_lt(ssn, cssn)) + break; + } + + + /* Insert before pos. */ + __skb_queue_before(&ulpq->lobby, pos, sctp_event2skb(event)); +} + +static struct sctp_ulpevent *sctp_ulpq_order(struct sctp_ulpq *ulpq, + struct sctp_ulpevent *event) +{ + __u16 sid, ssn; + struct sctp_stream *stream; + + /* Check if this message needs ordering. */ + if (event->msg_flags & SCTP_DATA_UNORDERED) + return event; + + /* Note: The stream ID must be verified before this routine. */ + sid = event->stream; + ssn = event->ssn; + stream = &ulpq->asoc->stream; + + /* Is this the expected SSN for this stream ID? */ + if (ssn != sctp_ssn_peek(stream, in, sid)) { + /* We've received something out of order, so find where it + * needs to be placed. We order by stream and then by SSN. + */ + sctp_ulpq_store_ordered(ulpq, event); + return NULL; + } + + /* Mark that the next chunk has been found. */ + sctp_ssn_next(stream, in, sid); + + /* Go find any other chunks that were waiting for + * ordering. + */ + sctp_ulpq_retrieve_ordered(ulpq, event); + + return 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) +{ + struct sk_buff *pos, *tmp; + struct sctp_ulpevent *cevent; + struct sctp_ulpevent *event; + struct sctp_stream *stream; + struct sk_buff_head temp; + struct sk_buff_head *lobby = &ulpq->lobby; + __u16 csid, cssn; + + stream = &ulpq->asoc->stream; + + /* We are holding the chunks by stream, by SSN. */ + skb_queue_head_init(&temp); + event = NULL; + sctp_skb_for_each(pos, lobby, tmp) { + cevent = (struct sctp_ulpevent *) pos->cb; + csid = cevent->stream; + cssn = cevent->ssn; + + /* Have we gone too far? */ + if (csid > sid) + break; + + /* Have we not gone far enough? */ + if (csid < sid) + continue; + + /* see if this ssn has been marked by skipping */ + if (!SSN_lt(cssn, sctp_ssn_peek(stream, in, csid))) + break; + + __skb_unlink(pos, lobby); + if (!event) + /* Create a temporary list to collect chunks on. */ + event = sctp_skb2event(pos); + + /* Attach all gathered skbs to the event. */ + __skb_queue_tail(&temp, pos); + } + + /* If we didn't reap any data, see if the next expected SSN + * is next on the queue and if so, use that. + */ + if (event == NULL && pos != (struct sk_buff *)lobby) { + cevent = (struct sctp_ulpevent *) pos->cb; + csid = cevent->stream; + cssn = cevent->ssn; + + if (csid == sid && cssn == sctp_ssn_peek(stream, in, csid)) { + sctp_ssn_next(stream, in, csid); + __skb_unlink(pos, lobby); + __skb_queue_tail(&temp, pos); + event = sctp_skb2event(pos); + } + } + + /* Send event to the ULP. 'event' is the sctp_ulpevent for + * very first SKB on the 'temp' list. + */ + if (event) { + /* see if we have more ordered that we can deliver */ + sctp_ulpq_retrieve_ordered(ulpq, event); + sctp_ulpq_tail_event(ulpq, &temp); + } +} + +/* 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) +{ + struct sctp_stream *stream; + + /* Note: The stream ID must be verified before this routine. */ + stream = &ulpq->asoc->stream; + + /* Is this an old SSN? If so ignore. */ + if (SSN_lt(ssn, sctp_ssn_peek(stream, in, sid))) + return; + + /* Mark that we are no longer expecting this SSN or lower. */ + sctp_ssn_skip(stream, in, sid, ssn); + + /* Go find any other chunks that were waiting for + * ordering and deliver them if needed. + */ + sctp_ulpq_reap_ordered(ulpq, sid); +} + +__u16 sctp_ulpq_renege_list(struct sctp_ulpq *ulpq, struct sk_buff_head *list, + __u16 needed) +{ + __u16 freed = 0; + __u32 tsn, last_tsn; + struct sk_buff *skb, *flist, *last; + struct sctp_ulpevent *event; + struct sctp_tsnmap *tsnmap; + + tsnmap = &ulpq->asoc->peer.tsn_map; + + while ((skb = skb_peek_tail(list)) != NULL) { + event = sctp_skb2event(skb); + tsn = event->tsn; + + /* Don't renege below the Cumulative TSN ACK Point. */ + if (TSN_lte(tsn, sctp_tsnmap_get_ctsn(tsnmap))) + break; + + /* Events in ordering queue may have multiple fragments + * corresponding to additional TSNs. Sum the total + * freed space; find the last TSN. + */ + freed += skb_headlen(skb); + flist = skb_shinfo(skb)->frag_list; + for (last = flist; flist; flist = flist->next) { + last = flist; + freed += skb_headlen(last); + } + if (last) + last_tsn = sctp_skb2event(last)->tsn; + else + last_tsn = tsn; + + /* Unlink the event, then renege all applicable TSNs. */ + __skb_unlink(skb, list); + sctp_ulpevent_free(event); + while (TSN_lte(tsn, last_tsn)) { + sctp_tsnmap_renege(tsnmap, tsn); + tsn++; + } + if (freed >= needed) + return freed; + } + + return freed; +} + +/* Renege 'needed' bytes from the ordering queue. */ +static __u16 sctp_ulpq_renege_order(struct sctp_ulpq *ulpq, __u16 needed) +{ + return sctp_ulpq_renege_list(ulpq, &ulpq->lobby, needed); +} + +/* Renege 'needed' bytes from the reassembly queue. */ +static __u16 sctp_ulpq_renege_frags(struct sctp_ulpq *ulpq, __u16 needed) +{ + return sctp_ulpq_renege_list(ulpq, &ulpq->reasm, needed); +} + +/* Partial deliver the first message as there is pressure on rwnd. */ +void sctp_ulpq_partial_delivery(struct sctp_ulpq *ulpq, + gfp_t gfp) +{ + struct sctp_ulpevent *event; + struct sctp_association *asoc; + struct sctp_sock *sp; + __u32 ctsn; + struct sk_buff *skb; + + asoc = ulpq->asoc; + sp = sctp_sk(asoc->base.sk); + + /* If the association is already in Partial Delivery mode + * we have nothing to do. + */ + if (ulpq->pd_mode) + return; + + /* Data must be at or below the Cumulative TSN ACK Point to + * start partial delivery. + */ + skb = skb_peek(&asoc->ulpq.reasm); + if (skb != NULL) { + ctsn = sctp_skb2event(skb)->tsn; + if (!TSN_lte(ctsn, sctp_tsnmap_get_ctsn(&asoc->peer.tsn_map))) + return; + } + + /* If the user enabled fragment interleave socket option, + * multiple associations can enter partial delivery. + * Otherwise, we can only enter partial delivery if the + * socket is not in partial deliver mode. + */ + if (sp->frag_interleave || atomic_read(&sp->pd_mode) == 0) { + /* Is partial delivery possible? */ + event = sctp_ulpq_retrieve_first(ulpq); + /* Send event to the ULP. */ + if (event) { + struct sk_buff_head temp; + + skb_queue_head_init(&temp); + __skb_queue_tail(&temp, sctp_event2skb(event)); + sctp_ulpq_tail_event(ulpq, &temp); + sctp_ulpq_set_pd(ulpq); + return; + } + } +} + +/* 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) +{ + struct sctp_association *asoc = ulpq->asoc; + __u32 freed = 0; + __u16 needed; + + needed = ntohs(chunk->chunk_hdr->length) - + sizeof(struct sctp_data_chunk); + + if (skb_queue_empty(&asoc->base.sk->sk_receive_queue)) { + freed = sctp_ulpq_renege_order(ulpq, needed); + if (freed < needed) + freed += sctp_ulpq_renege_frags(ulpq, needed - freed); + } + /* If able to free enough room, accept this chunk. */ + if (sk_rmem_schedule(asoc->base.sk, chunk->skb, needed) && + freed >= needed) { + int retval = sctp_ulpq_tail_data(ulpq, chunk, gfp); + /* + * Enter partial delivery if chunk has not been + * delivered; otherwise, drain the reassembly queue. + */ + if (retval <= 0) + sctp_ulpq_partial_delivery(ulpq, gfp); + else if (retval == 1) + sctp_ulpq_reasm_drain(ulpq); + } +} + +/* 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) +{ + struct sctp_ulpevent *ev = NULL; + struct sctp_sock *sp; + struct sock *sk; + + if (!ulpq->pd_mode) + return; + + sk = ulpq->asoc->base.sk; + sp = sctp_sk(sk); + if (sctp_ulpevent_type_enabled(ulpq->asoc->subscribe, + SCTP_PARTIAL_DELIVERY_EVENT)) + ev = sctp_ulpevent_make_pdapi(ulpq->asoc, + SCTP_PARTIAL_DELIVERY_ABORTED, + 0, 0, 0, gfp); + if (ev) + __skb_queue_tail(&sk->sk_receive_queue, sctp_event2skb(ev)); + + /* If there is data waiting, send it up the socket now. */ + if ((sctp_ulpq_clear_pd(ulpq) || ev) && !sp->data_ready_signalled) { + sp->data_ready_signalled = 1; + sk->sk_data_ready(sk); + } +} -- cgit v1.3.1