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-rw-r--r--net/sctp/chunk.c107
1 files changed, 32 insertions, 75 deletions
diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c
index 615f0ddd41df..e3621cb4827f 100644
--- a/net/sctp/chunk.c
+++ b/net/sctp/chunk.c
@@ -165,14 +165,12 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
struct sctp_sndrcvinfo *sinfo,
struct iov_iter *from)
{
- int max, whole, i, offset, over, err;
- int len, first_len;
- int max_data;
+ size_t len, first_len, max_data, remaining;
+ size_t msg_len = iov_iter_count(from);
+ struct list_head *pos, *temp;
struct sctp_chunk *chunk;
struct sctp_datamsg *msg;
- struct list_head *pos, *temp;
- size_t msg_len = iov_iter_count(from);
- __u8 frag;
+ int err;
msg = sctp_datamsg_new(GFP_KERNEL);
if (!msg)
@@ -185,7 +183,7 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
(SCTP_PR_TTL_ENABLED(sinfo->sinfo_flags) ||
!SCTP_PR_POLICY(sinfo->sinfo_flags)))
msg->expires_at = jiffies +
- msecs_to_jiffies(sinfo->sinfo_timetolive);
+ msecs_to_jiffies(sinfo->sinfo_timetolive);
/* This is the biggest possible DATA chunk that can fit into
* the packet
@@ -195,7 +193,6 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
sizeof(struct sctphdr) - sizeof(struct sctp_data_chunk);
max_data = SCTP_TRUNC4(max_data);
- max = asoc->frag_point;
/* If the the peer requested that we authenticate DATA chunks
* we need to account for bundling of the AUTH chunks along with
* DATA.
@@ -208,12 +205,11 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
hmac_desc->hmac_len);
}
- /* Now, check if we need to reduce our max */
- if (max > max_data)
- max = max_data;
+ /* Check what's our max considering the above */
+ max_data = min_t(size_t, max_data, asoc->frag_point);
- whole = 0;
- first_len = max;
+ /* 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.
@@ -224,40 +220,38 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
if (timer_pending(&asoc->timers[SCTP_EVENT_TIMEOUT_SACK]) &&
asoc->outqueue.out_qlen == 0 &&
list_empty(&asoc->outqueue.retransmit) &&
- msg_len > max)
- max_data -= SCTP_PAD4(sizeof(sctp_sack_chunk_t));
+ msg_len > max_data)
+ first_len -= SCTP_PAD4(sizeof(sctp_sack_chunk_t));
/* Encourage Cookie-ECHO bundling. */
if (asoc->state < SCTP_STATE_COOKIE_ECHOED)
- max_data -= SCTP_ARBITRARY_COOKIE_ECHO_LEN;
-
- /* Now that we adjusted completely, reset first_len */
- if (first_len > max_data)
- first_len = max_data;
+ first_len -= SCTP_ARBITRARY_COOKIE_ECHO_LEN;
/* Account for a different sized first fragment */
if (msg_len >= first_len) {
- msg_len -= first_len;
- whole = 1;
msg->can_delay = 0;
- }
-
- /* How many full sized? How many bytes leftover? */
- whole += msg_len / max;
- over = msg_len % max;
- offset = 0;
-
- if ((whole > 1) || (whole && over))
SCTP_INC_STATS(sock_net(asoc->base.sk), SCTP_MIB_FRAGUSRMSGS);
+ } else {
+ /* Which may be the only one... */
+ first_len = msg_len;
+ }
- /* Create chunks for all the full sized DATA chunks. */
- for (i = 0, len = first_len; i < whole; i++) {
- frag = SCTP_DATA_MIDDLE_FRAG;
+ /* Create chunks for all DATA chunks. */
+ for (remaining = msg_len; remaining; remaining -= len) {
+ u8 frag = SCTP_DATA_MIDDLE_FRAG;
- if (0 == i)
+ 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 ((i == (whole - 1)) && !over) {
+ 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
@@ -271,7 +265,6 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag,
0, GFP_KERNEL);
-
if (!chunk) {
err = -ENOMEM;
goto errout;
@@ -282,45 +275,8 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
goto errout_chunk_free;
/* Put the chunk->skb back into the form expected by send. */
- __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
- - (__u8 *)chunk->skb->data);
-
- sctp_datamsg_assign(msg, chunk);
- list_add_tail(&chunk->frag_list, &msg->chunks);
-
- /* The first chunk, the first chunk was likely short
- * to allow bundling, so reset to full size.
- */
- if (0 == i)
- len = max;
- }
-
- /* .. now the leftover bytes. */
- if (over) {
- if (!whole)
- frag = SCTP_DATA_NOT_FRAG;
- else
- frag = SCTP_DATA_LAST_FRAG;
-
- if ((sinfo->sinfo_flags & SCTP_EOF) ||
- (sinfo->sinfo_flags & SCTP_SACK_IMMEDIATELY))
- frag |= SCTP_DATA_SACK_IMM;
-
- chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag,
- 0, GFP_KERNEL);
-
- if (!chunk) {
- err = -ENOMEM;
- goto errout;
- }
-
- err = sctp_user_addto_chunk(chunk, over, from);
-
- /* Put the chunk->skb back into the form expected by send. */
- __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
- - (__u8 *)chunk->skb->data);
- if (err < 0)
- goto errout_chunk_free;
+ __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr -
+ chunk->skb->data);
sctp_datamsg_assign(msg, chunk);
list_add_tail(&chunk->frag_list, &msg->chunks);
@@ -338,6 +294,7 @@ errout:
sctp_chunk_free(chunk);
}
sctp_datamsg_put(msg);
+
return ERR_PTR(err);
}