1 /* SCTP kernel implementation
2 * (C) Copyright IBM Corp. 2003, 2004
4 * This file is part of the SCTP kernel implementation
6 * This file contains the code relating the chunk abstraction.
8 * This SCTP implementation is free software;
9 * you can redistribute it and/or modify it under the terms of
10 * the GNU General Public License as published by
11 * the Free Software Foundation; either version 2, or (at your option)
14 * This SCTP implementation is distributed in the hope that it
15 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
16 * ************************
17 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
18 * See the GNU General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with GNU CC; see the file COPYING. If not, write to
22 * the Free Software Foundation, 59 Temple Place - Suite 330,
23 * Boston, MA 02111-1307, USA.
25 * Please send any bug reports or fixes you make to the
27 * lksctp developers <lksctp-developers@lists.sourceforge.net>
29 * Or submit a bug report through the following website:
30 * http://www.sf.net/projects/lksctp
32 * Written or modified by:
33 * Jon Grimm <jgrimm@us.ibm.com>
34 * Sridhar Samudrala <sri@us.ibm.com>
36 * Any bugs reported given to us we will try to fix... any fixes shared will
37 * be incorporated into the next SCTP release.
40 #include <linux/types.h>
41 #include <linux/kernel.h>
42 #include <linux/net.h>
43 #include <linux/inet.h>
44 #include <linux/skbuff.h>
46 #include <net/sctp/sctp.h>
47 #include <net/sctp/sm.h>
49 /* This file is mostly in anticipation of future work, but initially
50 * populate with fragment tracking for an outbound message.
53 /* Initialize datamsg from memory. */
54 static void sctp_datamsg_init(struct sctp_datamsg *msg)
56 atomic_set(&msg->refcnt, 1);
61 INIT_LIST_HEAD(&msg->chunks);
64 /* Allocate and initialize datamsg. */
65 SCTP_STATIC struct sctp_datamsg *sctp_datamsg_new(gfp_t gfp)
67 struct sctp_datamsg *msg;
68 msg = kmalloc(sizeof(struct sctp_datamsg), gfp);
70 sctp_datamsg_init(msg);
71 SCTP_DBG_OBJCNT_INC(datamsg);
76 /* Final destructruction of datamsg memory. */
77 static void sctp_datamsg_destroy(struct sctp_datamsg *msg)
79 struct list_head *pos, *temp;
80 struct sctp_chunk *chunk;
82 struct sctp_ulpevent *ev;
83 struct sctp_association *asoc = NULL;
84 int error = 0, notify;
86 /* If we failed, we may need to notify. */
87 notify = msg->send_failed ? -1 : 0;
89 /* Release all references. */
90 list_for_each_safe(pos, temp, &msg->chunks) {
92 chunk = list_entry(pos, struct sctp_chunk, frag_list);
93 /* Check whether we _really_ need to notify. */
97 error = msg->send_error;
99 error = asoc->outqueue.error;
101 sp = sctp_sk(asoc->base.sk);
102 notify = sctp_ulpevent_type_enabled(SCTP_SEND_FAILED,
106 /* Generate a SEND FAILED event only if enabled. */
110 sent = SCTP_DATA_SENT;
112 sent = SCTP_DATA_UNSENT;
114 ev = sctp_ulpevent_make_send_failed(asoc, chunk, sent,
117 sctp_ulpq_tail_event(&asoc->ulpq, ev);
120 sctp_chunk_put(chunk);
123 SCTP_DBG_OBJCNT_DEC(datamsg);
127 /* Hold a reference. */
128 static void sctp_datamsg_hold(struct sctp_datamsg *msg)
130 atomic_inc(&msg->refcnt);
133 /* Release a reference. */
134 void sctp_datamsg_put(struct sctp_datamsg *msg)
136 if (atomic_dec_and_test(&msg->refcnt))
137 sctp_datamsg_destroy(msg);
140 /* Assign a chunk to this datamsg. */
141 static void sctp_datamsg_assign(struct sctp_datamsg *msg, struct sctp_chunk *chunk)
143 sctp_datamsg_hold(msg);
148 /* A data chunk can have a maximum payload of (2^16 - 20). Break
149 * down any such message into smaller chunks. Opportunistically, fragment
150 * the chunks down to the current MTU constraints. We may get refragmented
151 * later if the PMTU changes, but it is _much better_ to fragment immediately
152 * with a reasonable guess than always doing our fragmentation on the
155 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
156 struct sctp_sndrcvinfo *sinfo,
157 struct msghdr *msgh, int msg_len)
159 int max, whole, i, offset, over, err;
161 struct sctp_chunk *chunk;
162 struct sctp_datamsg *msg;
163 struct list_head *pos, *temp;
166 msg = sctp_datamsg_new(GFP_KERNEL);
170 /* Note: Calculate this outside of the loop, so that all fragments
171 * have the same expiration.
173 if (sinfo->sinfo_timetolive) {
174 /* sinfo_timetolive is in milliseconds */
175 msg->expires_at = jiffies +
176 msecs_to_jiffies(sinfo->sinfo_timetolive);
177 msg->can_abandon = 1;
178 SCTP_DEBUG_PRINTK("%s: msg:%p expires_at: %ld jiffies:%ld\n",
179 __func__, msg, msg->expires_at, jiffies);
182 max = asoc->frag_point;
184 /* If the the peer requested that we authenticate DATA chunks
185 * we need to accound for bundling of the AUTH chunks along with
188 if (sctp_auth_send_cid(SCTP_CID_DATA, asoc)) {
189 struct sctp_hmac *hmac_desc = sctp_auth_asoc_get_hmac(asoc);
192 max -= WORD_ROUND(sizeof(sctp_auth_chunk_t) +
193 hmac_desc->hmac_len);
199 /* Encourage Cookie-ECHO bundling. */
200 if (asoc->state < SCTP_STATE_COOKIE_ECHOED) {
201 whole = msg_len / (max - SCTP_ARBITRARY_COOKIE_ECHO_LEN);
203 /* Account for the DATA to be bundled with the COOKIE-ECHO. */
205 first_len = max - SCTP_ARBITRARY_COOKIE_ECHO_LEN;
206 msg_len -= first_len;
211 /* How many full sized? How many bytes leftover? */
212 whole += msg_len / max;
213 over = msg_len % max;
216 if ((whole > 1) || (whole && over))
217 SCTP_INC_STATS_USER(SCTP_MIB_FRAGUSRMSGS);
219 /* Create chunks for all the full sized DATA chunks. */
220 for (i=0, len=first_len; i < whole; i++) {
221 frag = SCTP_DATA_MIDDLE_FRAG;
224 frag |= SCTP_DATA_FIRST_FRAG;
226 if ((i == (whole - 1)) && !over)
227 frag |= SCTP_DATA_LAST_FRAG;
229 chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag, 0);
233 err = sctp_user_addto_chunk(chunk, offset, len, msgh->msg_iov);
239 /* Put the chunk->skb back into the form expected by send. */
240 __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
241 - (__u8 *)chunk->skb->data);
243 sctp_datamsg_assign(msg, chunk);
244 list_add_tail(&chunk->frag_list, &msg->chunks);
246 /* The first chunk, the first chunk was likely short
247 * to allow bundling, so reset to full size.
253 /* .. now the leftover bytes. */
256 frag = SCTP_DATA_NOT_FRAG;
258 frag = SCTP_DATA_LAST_FRAG;
260 chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag, 0);
265 err = sctp_user_addto_chunk(chunk, offset, over,msgh->msg_iov);
267 /* Put the chunk->skb back into the form expected by send. */
268 __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
269 - (__u8 *)chunk->skb->data);
273 sctp_datamsg_assign(msg, chunk);
274 list_add_tail(&chunk->frag_list, &msg->chunks);
280 list_for_each_safe(pos, temp, &msg->chunks) {
282 chunk = list_entry(pos, struct sctp_chunk, frag_list);
283 sctp_chunk_free(chunk);
285 sctp_datamsg_put(msg);
289 /* Check whether this message has expired. */
290 int sctp_chunk_abandoned(struct sctp_chunk *chunk)
292 struct sctp_datamsg *msg = chunk->msg;
294 if (!msg->can_abandon)
297 if (time_after(jiffies, msg->expires_at))
303 /* This chunk (and consequently entire message) has failed in its sending. */
304 void sctp_chunk_fail(struct sctp_chunk *chunk, int error)
306 chunk->msg->send_failed = 1;
307 chunk->msg->send_error = error;