From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- net/sctp/chunk.c | 353 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 353 insertions(+) create mode 100644 net/sctp/chunk.c (limited to 'net/sctp/chunk.c') diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c new file mode 100644 index 0000000000..fd4f8243cc --- /dev/null +++ b/net/sctp/chunk.c @@ -0,0 +1,353 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* SCTP kernel implementation + * (C) Copyright IBM Corp. 2003, 2004 + * + * This file is part of the SCTP kernel implementation + * + * This file contains the code relating the chunk abstraction. + * + * Please send any bug reports or fixes you make to the + * email address(es): + * lksctp developers + * + * Written or modified by: + * Jon Grimm + * Sridhar Samudrala + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* This file is mostly in anticipation of future work, but initially + * populate with fragment tracking for an outbound message. + */ + +/* Initialize datamsg from memory. */ +static void sctp_datamsg_init(struct sctp_datamsg *msg) +{ + refcount_set(&msg->refcnt, 1); + msg->send_failed = 0; + msg->send_error = 0; + msg->can_delay = 1; + msg->abandoned = 0; + msg->expires_at = 0; + INIT_LIST_HEAD(&msg->chunks); +} + +/* Allocate and initialize datamsg. */ +static struct sctp_datamsg *sctp_datamsg_new(gfp_t gfp) +{ + struct sctp_datamsg *msg; + msg = kmalloc(sizeof(struct sctp_datamsg), gfp); + if (msg) { + sctp_datamsg_init(msg); + SCTP_DBG_OBJCNT_INC(datamsg); + } + return msg; +} + +void sctp_datamsg_free(struct sctp_datamsg *msg) +{ + struct sctp_chunk *chunk; + + /* This doesn't have to be a _safe vairant because + * sctp_chunk_free() only drops the refs. + */ + list_for_each_entry(chunk, &msg->chunks, frag_list) + sctp_chunk_free(chunk); + + sctp_datamsg_put(msg); +} + +/* Final destructruction of datamsg memory. */ +static void sctp_datamsg_destroy(struct sctp_datamsg *msg) +{ + struct sctp_association *asoc = NULL; + struct list_head *pos, *temp; + struct sctp_chunk *chunk; + struct sctp_ulpevent *ev; + int error, sent; + + /* Release all references. */ + list_for_each_safe(pos, temp, &msg->chunks) { + list_del_init(pos); + chunk = list_entry(pos, struct sctp_chunk, frag_list); + + if (!msg->send_failed) { + sctp_chunk_put(chunk); + continue; + } + + asoc = chunk->asoc; + error = msg->send_error ?: asoc->outqueue.error; + sent = chunk->has_tsn ? SCTP_DATA_SENT : SCTP_DATA_UNSENT; + + if (sctp_ulpevent_type_enabled(asoc->subscribe, + SCTP_SEND_FAILED)) { + ev = sctp_ulpevent_make_send_failed(asoc, chunk, sent, + error, GFP_ATOMIC); + if (ev) + asoc->stream.si->enqueue_event(&asoc->ulpq, ev); + } + + if (sctp_ulpevent_type_enabled(asoc->subscribe, + SCTP_SEND_FAILED_EVENT)) { + ev = sctp_ulpevent_make_send_failed_event(asoc, chunk, + sent, error, + GFP_ATOMIC); + if (ev) + asoc->stream.si->enqueue_event(&asoc->ulpq, ev); + } + + sctp_chunk_put(chunk); + } + + SCTP_DBG_OBJCNT_DEC(datamsg); + kfree(msg); +} + +/* Hold a reference. */ +static void sctp_datamsg_hold(struct sctp_datamsg *msg) +{ + refcount_inc(&msg->refcnt); +} + +/* Release a reference. */ +void sctp_datamsg_put(struct sctp_datamsg *msg) +{ + if (refcount_dec_and_test(&msg->refcnt)) + sctp_datamsg_destroy(msg); +} + +/* Assign a chunk to this datamsg. */ +static void sctp_datamsg_assign(struct sctp_datamsg *msg, struct sctp_chunk *chunk) +{ + sctp_datamsg_hold(msg); + chunk->msg = msg; +} + + +/* A data chunk can have a maximum payload of (2^16 - 20). Break + * down any such message into smaller chunks. Opportunistically, fragment + * the chunks down to the current MTU constraints. We may get refragmented + * later if the PMTU changes, but it is _much better_ to fragment immediately + * with a reasonable guess than always doing our fragmentation on the + * soft-interrupt. + */ +struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc, + struct sctp_sndrcvinfo *sinfo, + struct iov_iter *from) +{ + size_t len, first_len, max_data, remaining; + size_t msg_len = iov_iter_count(from); + struct sctp_shared_key *shkey = NULL; + struct list_head *pos, *temp; + struct sctp_chunk *chunk; + struct sctp_datamsg *msg; + int err; + + msg = sctp_datamsg_new(GFP_KERNEL); + if (!msg) + return ERR_PTR(-ENOMEM); + + /* Note: Calculate this outside of the loop, so that all fragments + * have the same expiration. + */ + if (asoc->peer.prsctp_capable && sinfo->sinfo_timetolive && + (SCTP_PR_TTL_ENABLED(sinfo->sinfo_flags) || + !SCTP_PR_POLICY(sinfo->sinfo_flags))) + msg->expires_at = jiffies + + msecs_to_jiffies(sinfo->sinfo_timetolive); + + /* This is the biggest possible DATA chunk that can fit into + * the packet + */ + max_data = asoc->frag_point; + if (unlikely(!max_data)) { + max_data = sctp_min_frag_point(sctp_sk(asoc->base.sk), + sctp_datachk_len(&asoc->stream)); + pr_warn_ratelimited("%s: asoc:%p frag_point is zero, forcing max_data to default minimum (%zu)", + __func__, asoc, max_data); + } + + /* If the peer requested that we authenticate DATA chunks + * we need to account for bundling of the AUTH chunks along with + * DATA. + */ + if (sctp_auth_send_cid(SCTP_CID_DATA, asoc)) { + struct sctp_hmac *hmac_desc = sctp_auth_asoc_get_hmac(asoc); + + if (hmac_desc) + max_data -= SCTP_PAD4(sizeof(struct sctp_auth_chunk) + + hmac_desc->hmac_len); + + if (sinfo->sinfo_tsn && + sinfo->sinfo_ssn != asoc->active_key_id) { + shkey = sctp_auth_get_shkey(asoc, sinfo->sinfo_ssn); + if (!shkey) { + err = -EINVAL; + goto errout; + } + } else { + shkey = asoc->shkey; + } + } + + /* Set first_len and then account for possible bundles on first frag */ + first_len = max_data; + + /* Check to see if we have a pending SACK and try to let it be bundled + * with this message. Do this if we don't have any data queued already. + * To check that, look at out_qlen and retransmit list. + * NOTE: we will not reduce to account for SACK, if the message would + * not have been fragmented. + */ + if (timer_pending(&asoc->timers[SCTP_EVENT_TIMEOUT_SACK]) && + asoc->outqueue.out_qlen == 0 && + list_empty(&asoc->outqueue.retransmit) && + msg_len > max_data) + first_len -= SCTP_PAD4(sizeof(struct sctp_sack_chunk)); + + /* Encourage Cookie-ECHO bundling. */ + if (asoc->state < SCTP_STATE_COOKIE_ECHOED) + first_len -= SCTP_ARBITRARY_COOKIE_ECHO_LEN; + + /* Account for a different sized first fragment */ + if (msg_len >= first_len) { + msg->can_delay = 0; + if (msg_len > first_len) + SCTP_INC_STATS(asoc->base.net, + SCTP_MIB_FRAGUSRMSGS); + } else { + /* Which may be the only one... */ + first_len = msg_len; + } + + /* Create chunks for all DATA chunks. */ + for (remaining = msg_len; remaining; remaining -= len) { + u8 frag = SCTP_DATA_MIDDLE_FRAG; + + if (remaining == msg_len) { + /* First frag, which may also be the last */ + frag |= SCTP_DATA_FIRST_FRAG; + len = first_len; + } else { + /* Middle frags */ + len = max_data; + } + + if (len >= remaining) { + /* Last frag, which may also be the first */ + len = remaining; + frag |= SCTP_DATA_LAST_FRAG; + + /* The application requests to set the I-bit of the + * last DATA chunk of a user message when providing + * the user message to the SCTP implementation. + */ + if ((sinfo->sinfo_flags & SCTP_EOF) || + (sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY)) + frag |= SCTP_DATA_SACK_IMM; + } + + chunk = asoc->stream.si->make_datafrag(asoc, sinfo, len, frag, + GFP_KERNEL); + if (!chunk) { + err = -ENOMEM; + goto errout; + } + + err = sctp_user_addto_chunk(chunk, len, from); + if (err < 0) + goto errout_chunk_free; + + chunk->shkey = shkey; + + /* Put the chunk->skb back into the form expected by send. */ + __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr - + chunk->skb->data); + + sctp_datamsg_assign(msg, chunk); + list_add_tail(&chunk->frag_list, &msg->chunks); + } + + return msg; + +errout_chunk_free: + sctp_chunk_free(chunk); + +errout: + list_for_each_safe(pos, temp, &msg->chunks) { + list_del_init(pos); + chunk = list_entry(pos, struct sctp_chunk, frag_list); + sctp_chunk_free(chunk); + } + sctp_datamsg_put(msg); + + return ERR_PTR(err); +} + +/* Check whether this message has expired. */ +int sctp_chunk_abandoned(struct sctp_chunk *chunk) +{ + if (!chunk->asoc->peer.prsctp_capable) + return 0; + + if (chunk->msg->abandoned) + return 1; + + if (!chunk->has_tsn && + !(chunk->chunk_hdr->flags & SCTP_DATA_FIRST_FRAG)) + return 0; + + if (SCTP_PR_TTL_ENABLED(chunk->sinfo.sinfo_flags) && + time_after(jiffies, chunk->msg->expires_at)) { + struct sctp_stream_out *streamout = + SCTP_SO(&chunk->asoc->stream, + chunk->sinfo.sinfo_stream); + + if (chunk->sent_count) { + chunk->asoc->abandoned_sent[SCTP_PR_INDEX(TTL)]++; + streamout->ext->abandoned_sent[SCTP_PR_INDEX(TTL)]++; + } else { + chunk->asoc->abandoned_unsent[SCTP_PR_INDEX(TTL)]++; + streamout->ext->abandoned_unsent[SCTP_PR_INDEX(TTL)]++; + } + chunk->msg->abandoned = 1; + return 1; + } else if (SCTP_PR_RTX_ENABLED(chunk->sinfo.sinfo_flags) && + chunk->sent_count > chunk->sinfo.sinfo_timetolive) { + struct sctp_stream_out *streamout = + SCTP_SO(&chunk->asoc->stream, + chunk->sinfo.sinfo_stream); + + chunk->asoc->abandoned_sent[SCTP_PR_INDEX(RTX)]++; + streamout->ext->abandoned_sent[SCTP_PR_INDEX(RTX)]++; + chunk->msg->abandoned = 1; + return 1; + } else if (!SCTP_PR_POLICY(chunk->sinfo.sinfo_flags) && + chunk->msg->expires_at && + time_after(jiffies, chunk->msg->expires_at)) { + chunk->msg->abandoned = 1; + return 1; + } + /* PRIO policy is processed by sendmsg, not here */ + + return 0; +} + +/* This chunk (and consequently entire message) has failed in its sending. */ +void sctp_chunk_fail(struct sctp_chunk *chunk, int error) +{ + chunk->msg->send_failed = 1; + chunk->msg->send_error = error; +} -- cgit v1.2.3