ia64/linux-2.6.18-xen.hg

view net/sctp/chunk.c @ 871:9cbcc9008446

xen/x86: don't initialize cpu_data[]'s apicid field on generic code

Afaict, this is not only redundant with the intialization done in
drivers/xen/core/smpboot.c, but actually results - at least for
secondary CPUs - in the Xen-specific value written to be later
overwritten with whatever the generic code determines (with no
guarantee that the two values are identical).

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu May 14 10:09:15 2009 +0100 (2009-05-14)
parents 831230e53067
children
line source
1 /* SCTP kernel reference Implementation
2 * (C) Copyright IBM Corp. 2003, 2004
3 *
4 * This file is part of the SCTP kernel reference Implementation
5 *
6 * This file contains the code relating the the chunk abstraction.
7 *
8 * The SCTP reference 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)
12 * any later version.
13 *
14 * The SCTP reference 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.
19 *
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.
24 *
25 * Please send any bug reports or fixes you make to the
26 * email address(es):
27 * lksctp developers <lksctp-developers@lists.sourceforge.net>
28 *
29 * Or submit a bug report through the following website:
30 * http://www.sf.net/projects/lksctp
31 *
32 * Written or modified by:
33 * Jon Grimm <jgrimm@us.ibm.com>
34 * Sridhar Samudrala <sri@us.ibm.com>
35 *
36 * Any bugs reported given to us we will try to fix... any fixes shared will
37 * be incorporated into the next SCTP release.
38 */
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>
45 #include <net/sock.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.
51 */
53 /* Initialize datamsg from memory. */
54 static void sctp_datamsg_init(struct sctp_datamsg *msg)
55 {
56 atomic_set(&msg->refcnt, 1);
57 msg->send_failed = 0;
58 msg->send_error = 0;
59 msg->can_abandon = 0;
60 msg->expires_at = 0;
61 INIT_LIST_HEAD(&msg->chunks);
62 }
64 /* Allocate and initialize datamsg. */
65 SCTP_STATIC struct sctp_datamsg *sctp_datamsg_new(gfp_t gfp)
66 {
67 struct sctp_datamsg *msg;
68 msg = kmalloc(sizeof(struct sctp_datamsg), gfp);
69 if (msg)
70 sctp_datamsg_init(msg);
71 SCTP_DBG_OBJCNT_INC(datamsg);
72 return msg;
73 }
75 /* Final destructruction of datamsg memory. */
76 static void sctp_datamsg_destroy(struct sctp_datamsg *msg)
77 {
78 struct list_head *pos, *temp;
79 struct sctp_chunk *chunk;
80 struct sctp_sock *sp;
81 struct sctp_ulpevent *ev;
82 struct sctp_association *asoc = NULL;
83 int error = 0, notify;
85 /* If we failed, we may need to notify. */
86 notify = msg->send_failed ? -1 : 0;
88 /* Release all references. */
89 list_for_each_safe(pos, temp, &msg->chunks) {
90 list_del_init(pos);
91 chunk = list_entry(pos, struct sctp_chunk, frag_list);
92 /* Check whether we _really_ need to notify. */
93 if (notify < 0) {
94 asoc = chunk->asoc;
95 if (msg->send_error)
96 error = msg->send_error;
97 else
98 error = asoc->outqueue.error;
100 sp = sctp_sk(asoc->base.sk);
101 notify = sctp_ulpevent_type_enabled(SCTP_SEND_FAILED,
102 &sp->subscribe);
103 }
105 /* Generate a SEND FAILED event only if enabled. */
106 if (notify > 0) {
107 int sent;
108 if (chunk->has_tsn)
109 sent = SCTP_DATA_SENT;
110 else
111 sent = SCTP_DATA_UNSENT;
113 ev = sctp_ulpevent_make_send_failed(asoc, chunk, sent,
114 error, GFP_ATOMIC);
115 if (ev)
116 sctp_ulpq_tail_event(&asoc->ulpq, ev);
117 }
119 sctp_chunk_put(chunk);
120 }
122 SCTP_DBG_OBJCNT_DEC(datamsg);
123 kfree(msg);
124 }
126 /* Hold a reference. */
127 static void sctp_datamsg_hold(struct sctp_datamsg *msg)
128 {
129 atomic_inc(&msg->refcnt);
130 }
132 /* Release a reference. */
133 void sctp_datamsg_put(struct sctp_datamsg *msg)
134 {
135 if (atomic_dec_and_test(&msg->refcnt))
136 sctp_datamsg_destroy(msg);
137 }
139 /* Free a message. Really just give up a reference, the
140 * really free happens in sctp_datamsg_destroy().
141 */
142 void sctp_datamsg_free(struct sctp_datamsg *msg)
143 {
144 sctp_datamsg_put(msg);
145 }
147 /* Hold on to all the fragments until all chunks have been sent. */
148 void sctp_datamsg_track(struct sctp_chunk *chunk)
149 {
150 sctp_chunk_hold(chunk);
151 }
153 /* Assign a chunk to this datamsg. */
154 static void sctp_datamsg_assign(struct sctp_datamsg *msg, struct sctp_chunk *chunk)
155 {
156 sctp_datamsg_hold(msg);
157 chunk->msg = msg;
158 }
161 /* A data chunk can have a maximum payload of (2^16 - 20). Break
162 * down any such message into smaller chunks. Opportunistically, fragment
163 * the chunks down to the current MTU constraints. We may get refragmented
164 * later if the PMTU changes, but it is _much better_ to fragment immediately
165 * with a reasonable guess than always doing our fragmentation on the
166 * soft-interrupt.
167 */
168 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
169 struct sctp_sndrcvinfo *sinfo,
170 struct msghdr *msgh, int msg_len)
171 {
172 int max, whole, i, offset, over, err;
173 int len, first_len;
174 struct sctp_chunk *chunk;
175 struct sctp_datamsg *msg;
176 struct list_head *pos, *temp;
177 __u8 frag;
179 msg = sctp_datamsg_new(GFP_KERNEL);
180 if (!msg)
181 return NULL;
183 /* Note: Calculate this outside of the loop, so that all fragments
184 * have the same expiration.
185 */
186 if (sinfo->sinfo_timetolive) {
187 /* sinfo_timetolive is in milliseconds */
188 msg->expires_at = jiffies +
189 msecs_to_jiffies(sinfo->sinfo_timetolive);
190 msg->can_abandon = 1;
191 SCTP_DEBUG_PRINTK("%s: msg:%p expires_at: %ld jiffies:%ld\n",
192 __FUNCTION__, msg, msg->expires_at, jiffies);
193 }
195 max = asoc->frag_point;
197 whole = 0;
198 first_len = max;
200 /* Encourage Cookie-ECHO bundling. */
201 if (asoc->state < SCTP_STATE_COOKIE_ECHOED) {
202 whole = msg_len / (max - SCTP_ARBITRARY_COOKIE_ECHO_LEN);
204 /* Account for the DATA to be bundled with the COOKIE-ECHO. */
205 if (whole) {
206 first_len = max - SCTP_ARBITRARY_COOKIE_ECHO_LEN;
207 msg_len -= first_len;
208 whole = 1;
209 }
210 }
212 /* How many full sized? How many bytes leftover? */
213 whole += msg_len / max;
214 over = msg_len % max;
215 offset = 0;
217 if ((whole > 1) || (whole && over))
218 SCTP_INC_STATS_USER(SCTP_MIB_FRAGUSRMSGS);
220 /* Create chunks for all the full sized DATA chunks. */
221 for (i=0, len=first_len; i < whole; i++) {
222 frag = SCTP_DATA_MIDDLE_FRAG;
224 if (0 == i)
225 frag |= SCTP_DATA_FIRST_FRAG;
227 if ((i == (whole - 1)) && !over)
228 frag |= SCTP_DATA_LAST_FRAG;
230 chunk = sctp_make_datafrag_empty(asoc, sinfo, len, frag, 0);
232 if (!chunk)
233 goto errout;
234 err = sctp_user_addto_chunk(chunk, offset, len, msgh->msg_iov);
235 if (err < 0)
236 goto errout;
238 offset += len;
240 /* Put the chunk->skb back into the form expected by send. */
241 __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
242 - (__u8 *)chunk->skb->data);
244 sctp_datamsg_assign(msg, chunk);
245 list_add_tail(&chunk->frag_list, &msg->chunks);
247 /* The first chunk, the first chunk was likely short
248 * to allow bundling, so reset to full size.
249 */
250 if (0 == i)
251 len = max;
252 }
254 /* .. now the leftover bytes. */
255 if (over) {
256 if (!whole)
257 frag = SCTP_DATA_NOT_FRAG;
258 else
259 frag = SCTP_DATA_LAST_FRAG;
261 chunk = sctp_make_datafrag_empty(asoc, sinfo, over, frag, 0);
263 if (!chunk)
264 goto errout;
266 err = sctp_user_addto_chunk(chunk, offset, over,msgh->msg_iov);
268 /* Put the chunk->skb back into the form expected by send. */
269 __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
270 - (__u8 *)chunk->skb->data);
271 if (err < 0)
272 goto errout;
274 sctp_datamsg_assign(msg, chunk);
275 list_add_tail(&chunk->frag_list, &msg->chunks);
276 }
278 return msg;
280 errout:
281 list_for_each_safe(pos, temp, &msg->chunks) {
282 list_del_init(pos);
283 chunk = list_entry(pos, struct sctp_chunk, frag_list);
284 sctp_chunk_free(chunk);
285 }
286 sctp_datamsg_free(msg);
287 return NULL;
288 }
290 /* Check whether this message has expired. */
291 int sctp_chunk_abandoned(struct sctp_chunk *chunk)
292 {
293 struct sctp_datamsg *msg = chunk->msg;
295 if (!msg->can_abandon)
296 return 0;
298 if (time_after(jiffies, msg->expires_at))
299 return 1;
301 return 0;
302 }
304 /* This chunk (and consequently entire message) has failed in its sending. */
305 void sctp_chunk_fail(struct sctp_chunk *chunk, int error)
306 {
307 chunk->msg->send_failed = 1;
308 chunk->msg->send_error = error;
309 }