diff options
| -rw-r--r-- | net/sctp/chunk.c | 107 |
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); } |