ia64/linux-2.6.18-xen.hg

view net/sctp/inqueue.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 * Copyright (c) 1999-2000 Cisco, Inc.
3 * Copyright (c) 1999-2001 Motorola, Inc.
4 * Copyright (c) 2002 International Business Machines, Corp.
5 *
6 * This file is part of the SCTP kernel reference Implementation
7 *
8 * These functions are the methods for accessing the SCTP inqueue.
9 *
10 * An SCTP inqueue is a queue into which you push SCTP packets
11 * (which might be bundles or fragments of chunks) and out of which you
12 * pop SCTP whole chunks.
13 *
14 * The SCTP reference implementation is free software;
15 * you can redistribute it and/or modify it under the terms of
16 * the GNU General Public License as published by
17 * the Free Software Foundation; either version 2, or (at your option)
18 * any later version.
19 *
20 * The SCTP reference implementation is distributed in the hope that it
21 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
22 * ************************
23 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
24 * See the GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with GNU CC; see the file COPYING. If not, write to
28 * the Free Software Foundation, 59 Temple Place - Suite 330,
29 * Boston, MA 02111-1307, USA.
30 *
31 * Please send any bug reports or fixes you make to the
32 * email address(es):
33 * lksctp developers <lksctp-developers@lists.sourceforge.net>
34 *
35 * Or submit a bug report through the following website:
36 * http://www.sf.net/projects/lksctp
37 *
38 * Written or modified by:
39 * La Monte H.P. Yarroll <piggy@acm.org>
40 * Karl Knutson <karl@athena.chicago.il.us>
41 *
42 * Any bugs reported given to us we will try to fix... any fixes shared will
43 * be incorporated into the next SCTP release.
44 */
46 #include <net/sctp/sctp.h>
47 #include <net/sctp/sm.h>
48 #include <linux/interrupt.h>
50 /* Initialize an SCTP inqueue. */
51 void sctp_inq_init(struct sctp_inq *queue)
52 {
53 INIT_LIST_HEAD(&queue->in_chunk_list);
54 queue->in_progress = NULL;
56 /* Create a task for delivering data. */
57 INIT_WORK(&queue->immediate, NULL, NULL);
59 queue->malloced = 0;
60 }
62 /* Release the memory associated with an SCTP inqueue. */
63 void sctp_inq_free(struct sctp_inq *queue)
64 {
65 struct sctp_chunk *chunk, *tmp;
67 /* Empty the queue. */
68 list_for_each_entry_safe(chunk, tmp, &queue->in_chunk_list, list) {
69 list_del_init(&chunk->list);
70 sctp_chunk_free(chunk);
71 }
73 /* If there is a packet which is currently being worked on,
74 * free it as well.
75 */
76 if (queue->in_progress) {
77 sctp_chunk_free(queue->in_progress);
78 queue->in_progress = NULL;
79 }
81 if (queue->malloced) {
82 /* Dump the master memory segment. */
83 kfree(queue);
84 }
85 }
87 /* Put a new packet in an SCTP inqueue.
88 * We assume that packet->sctp_hdr is set and in host byte order.
89 */
90 void sctp_inq_push(struct sctp_inq *q, struct sctp_chunk *packet)
91 {
92 /* Directly call the packet handling routine. */
94 /* We are now calling this either from the soft interrupt
95 * or from the backlog processing.
96 * Eventually, we should clean up inqueue to not rely
97 * on the BH related data structures.
98 */
99 list_add_tail(&packet->list, &q->in_chunk_list);
100 q->immediate.func(q->immediate.data);
101 }
103 /* Extract a chunk from an SCTP inqueue.
104 *
105 * WARNING: If you need to put the chunk on another queue, you need to
106 * make a shallow copy (clone) of it.
107 */
108 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue)
109 {
110 struct sctp_chunk *chunk;
111 sctp_chunkhdr_t *ch = NULL;
113 /* The assumption is that we are safe to process the chunks
114 * at this time.
115 */
117 if ((chunk = queue->in_progress)) {
118 /* There is a packet that we have been working on.
119 * Any post processing work to do before we move on?
120 */
121 if (chunk->singleton ||
122 chunk->end_of_packet ||
123 chunk->pdiscard) {
124 sctp_chunk_free(chunk);
125 chunk = queue->in_progress = NULL;
126 } else {
127 /* Nothing to do. Next chunk in the packet, please. */
128 ch = (sctp_chunkhdr_t *) chunk->chunk_end;
130 /* Force chunk->skb->data to chunk->chunk_end. */
131 skb_pull(chunk->skb,
132 chunk->chunk_end - chunk->skb->data);
133 }
134 }
136 /* Do we need to take the next packet out of the queue to process? */
137 if (!chunk) {
138 struct list_head *entry;
140 /* Is the queue empty? */
141 if (list_empty(&queue->in_chunk_list))
142 return NULL;
144 entry = queue->in_chunk_list.next;
145 chunk = queue->in_progress =
146 list_entry(entry, struct sctp_chunk, list);
147 list_del_init(entry);
149 /* This is the first chunk in the packet. */
150 chunk->singleton = 1;
151 ch = (sctp_chunkhdr_t *) chunk->skb->data;
152 chunk->data_accepted = 0;
153 }
155 chunk->chunk_hdr = ch;
156 chunk->chunk_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
157 /* In the unlikely case of an IP reassembly, the skb could be
158 * non-linear. If so, update chunk_end so that it doesn't go past
159 * the skb->tail.
160 */
161 if (unlikely(skb_is_nonlinear(chunk->skb))) {
162 if (chunk->chunk_end > chunk->skb->tail)
163 chunk->chunk_end = chunk->skb->tail;
164 }
165 skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t));
166 chunk->subh.v = NULL; /* Subheader is no longer valid. */
168 if (chunk->chunk_end < chunk->skb->tail) {
169 /* This is not a singleton */
170 chunk->singleton = 0;
171 } else if (chunk->chunk_end > chunk->skb->tail) {
172 /* RFC 2960, Section 6.10 Bundling
173 *
174 * Partial chunks MUST NOT be placed in an SCTP packet.
175 * If the receiver detects a partial chunk, it MUST drop
176 * the chunk.
177 *
178 * Since the end of the chunk is past the end of our buffer
179 * (which contains the whole packet, we can freely discard
180 * the whole packet.
181 */
182 sctp_chunk_free(chunk);
183 chunk = queue->in_progress = NULL;
185 return NULL;
186 } else {
187 /* We are at the end of the packet, so mark the chunk
188 * in case we need to send a SACK.
189 */
190 chunk->end_of_packet = 1;
191 }
193 SCTP_DEBUG_PRINTK("+++sctp_inq_pop+++ chunk %p[%s],"
194 " length %d, skb->len %d\n",chunk,
195 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)),
196 ntohs(chunk->chunk_hdr->length), chunk->skb->len);
197 return chunk;
198 }
200 /* Set a top-half handler.
201 *
202 * Originally, we the top-half handler was scheduled as a BH. We now
203 * call the handler directly in sctp_inq_push() at a time that
204 * we know we are lock safe.
205 * The intent is that this routine will pull stuff out of the
206 * inqueue and process it.
207 */
208 void sctp_inq_set_th_handler(struct sctp_inq *q,
209 void (*callback)(void *), void *arg)
210 {
211 INIT_WORK(&q->immediate, callback, arg);
212 }