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