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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/sctp/chunk.c | |
download | linux-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.bz2 |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'net/sctp/chunk.c')
-rw-r--r-- | net/sctp/chunk.c | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c new file mode 100644 index 000000000000..0c2ab7885058 --- /dev/null +++ b/net/sctp/chunk.c @@ -0,0 +1,309 @@ +/* SCTP kernel reference Implementation + * (C) Copyright IBM Corp. 2003, 2004 + * + * This file is part of the SCTP kernel reference Implementation + * + * This file contains the code relating the the chunk abstraction. + * + * The SCTP reference implementation is free software; + * you can redistribute it and/or modify it under the terms of + * the GNU General Public License as published by + * the Free Software Foundation; either version 2, or (at your option) + * any later version. + * + * The SCTP reference implementation is distributed in the hope that it + * will be useful, but WITHOUT ANY WARRANTY; without even the implied + * ************************ + * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + * See the GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with GNU CC; see the file COPYING. If not, write to + * the Free Software Foundation, 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + * + * Please send any bug reports or fixes you make to the + * email address(es): + * lksctp developers <lksctp-developers@lists.sourceforge.net> + * + * Or submit a bug report through the following website: + * http://www.sf.net/projects/lksctp + * + * Written or modified by: + * Jon Grimm <jgrimm@us.ibm.com> + * Sridhar Samudrala <sri@us.ibm.com> + * + * Any bugs reported given to us we will try to fix... any fixes shared will + * be incorporated into the next SCTP release. + */ + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/net.h> +#include <linux/inet.h> +#include <linux/skbuff.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) +{ + atomic_set(&msg->refcnt, 1); + msg->send_failed = 0; + msg->send_error = 0; + msg->can_abandon = 0; + msg->expires_at = 0; + INIT_LIST_HEAD(&msg->chunks); +} + +/* Allocate and initialize datamsg. */ +SCTP_STATIC struct sctp_datamsg *sctp_datamsg_new(int 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; +} + +/* Final destructruction of datamsg memory. */ +static void sctp_datamsg_destroy(struct sctp_datamsg *msg) +{ + struct list_head *pos, *temp; + struct sctp_chunk *chunk; + struct sctp_sock *sp; + struct sctp_ulpevent *ev; + struct sctp_association *asoc = NULL; + int error = 0, notify; + + /* If we failed, we may need to notify. */ + notify = msg->send_failed ? -1 : 0; + + /* Release all references. */ + list_for_each_safe(pos, temp, &msg->chunks) { + list_del_init(pos); + chunk = list_entry(pos, struct sctp_chunk, frag_list); + /* Check whether we _really_ need to notify. */ + if (notify < 0) { + asoc = chunk->asoc; + if (msg->send_error) + error = msg->send_error; + else + error = asoc->outqueue.error; + + sp = sctp_sk(asoc->base.sk); + notify = sctp_ulpevent_type_enabled(SCTP_SEND_FAILED, + &sp->subscribe); + } + + /* Generate a SEND FAILED event only if enabled. */ + if (notify > 0) { + int sent; + if (chunk->has_tsn) + sent = SCTP_DATA_SENT; + else + sent = SCTP_DATA_UNSENT; + + ev = sctp_ulpevent_make_send_failed(asoc, chunk, sent, + error, GFP_ATOMIC); + if (ev) + sctp_ulpq_tail_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) +{ + atomic_inc(&msg->refcnt); +} + +/* Release a reference. */ +void sctp_datamsg_put(struct sctp_datamsg *msg) +{ + if (atomic_dec_and_test(&msg->refcnt)) + sctp_datamsg_destroy(msg); +} + +/* Free a message. Really just give up a reference, the + * really free happens in sctp_datamsg_destroy(). + */ +void sctp_datamsg_free(struct sctp_datamsg *msg) +{ + sctp_datamsg_put(msg); +} + +/* Hold on to all the fragments until all chunks have been sent. */ +void sctp_datamsg_track(struct sctp_chunk *chunk) +{ + sctp_chunk_hold(chunk); +} + +/* 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 msghdr *msgh, int msg_len) +{ + int max, whole, i, offset, over, err; + int len, first_len; + struct sctp_chunk *chunk; + struct sctp_datamsg *msg; + struct list_head *pos, *temp; + __u8 frag; + + msg = sctp_datamsg_new(GFP_KERNEL); + if (!msg) + return NULL; + + /* Note: Calculate this outside of the loop, so that all fragments + * have the same expiration. + */ + if (sinfo->sinfo_timetolive) { + /* sinfo_timetolive is in milliseconds */ + msg->expires_at = jiffies + + msecs_to_jiffies(sinfo->sinfo_timetolive); + msg->can_abandon = 1; + SCTP_DEBUG_PRINTK("%s: msg:%p expires_at: %ld jiffies:%ld\n", + __FUNCTION__, msg, msg->expires_at, jiffies); + } + + max = asoc->frag_point; + + whole = 0; + first_len = max; + + /* Encourage Cookie-ECHO bundling. */ + if (asoc->state < SCTP_STATE_COOKIE_ECHOED) { + whole = msg_len / (max - SCTP_ARBITRARY_COOKIE_ECHO_LEN); + + /* Account for the DATA to be bundled with the COOKIE-ECHO. */ + if (whole) { + first_len = max - SCTP_ARBITRARY_COOKIE_ECHO_LEN; + msg_len -= first_len; + whole = 1; + } + } + + /* 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_USER(SCTP_MIB_FRAGUSRMSGS); + + /* Create chunks for all the full sized DATA chunks. */ + for (i=0, len=first_len; i < whole; i++) { + frag = SCTP_DATA_MIDDLE_FRAG; + + if (0 == i) + frag |= SCTP_DATA_FIRST_FRAG; + + if ((i == (whole - 1)) && !over) + frag |= SCTP_DATA_LAST_FRAG; + + chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag, 0); + + if (!chunk) + goto errout; + err = sctp_user_addto_chunk(chunk, offset, len, msgh->msg_iov); + if (err < 0) + goto errout; + + offset += len; + + /* 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; + + chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag, 0); + + if (!chunk) + goto errout; + + err = sctp_user_addto_chunk(chunk, offset, over,msgh->msg_iov); + + /* 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; + + sctp_datamsg_assign(msg, chunk); + list_add_tail(&chunk->frag_list, &msg->chunks); + } + + return msg; + +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_free(msg); + return NULL; +} + +/* Check whether this message has expired. */ +int sctp_chunk_abandoned(struct sctp_chunk *chunk) +{ + struct sctp_datamsg *msg = chunk->msg; + + if (!msg->can_abandon) + return 0; + + if (time_after(jiffies, msg->expires_at)) + return 1; + + 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; +} |