Orange Pi5 kernel

// 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 <linux-sctp@vger.kernel.org>
 *
 * Written or modified by:
 *    Jon Grimm             <jgrimm@us.ibm.com>
 *    Sridhar Samudrala     <sri@us.ibm.com>
 */
 
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/net.h>
#include <linux/inet.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <net/sock.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>
 
/* 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;
}