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Vlad Yasevich60c778b2008-01-11 09:57:09 -05001/* SCTP kernel implementation
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 * Copyright (c) 1999-2000 Cisco, Inc.
3 * Copyright (c) 1999-2001 Motorola, Inc.
4 * Copyright (c) 2002 International Business Machines, Corp.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09005 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -05006 * This file is part of the SCTP kernel implementation
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +09007 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * 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.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +090013 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050014 * This SCTP implementation is free software;
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +090015 * you can redistribute it and/or modify it under the terms of
Linus Torvalds1da177e2005-04-16 15:20:36 -070016 * the GNU General Public License as published by
17 * the Free Software Foundation; either version 2, or (at your option)
18 * any later version.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +090019 *
Vlad Yasevich60c778b2008-01-11 09:57:09 -050020 * This SCTP implementation is distributed in the hope that it
Linus Torvalds1da177e2005-04-16 15:20:36 -070021 * 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.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +090025 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070026 * 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,
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +090029 * Boston, MA 02111-1307, USA.
30 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070031 * Please send any bug reports or fixes you make to the
32 * email address(es):
33 * lksctp developers <lksctp-developers@lists.sourceforge.net>
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +090034 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070035 * Or submit a bug report through the following website:
36 * http://www.sf.net/projects/lksctp
37 *
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +090038 * Written or modified by:
Linus Torvalds1da177e2005-04-16 15:20:36 -070039 * La Monte H.P. Yarroll <piggy@acm.org>
40 * Karl Knutson <karl@athena.chicago.il.us>
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +090041 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070042 * Any bugs reported given to us we will try to fix... any fixes shared will
43 * be incorporated into the next SCTP release.
44 */
45
46#include <net/sctp/sctp.h>
47#include <net/sctp/sm.h>
48#include <linux/interrupt.h>
49
50/* Initialize an SCTP inqueue. */
51void sctp_inq_init(struct sctp_inq *queue)
52{
David S. Miller79af02c2005-07-08 21:47:49 -070053 INIT_LIST_HEAD(&queue->in_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070054 queue->in_progress = NULL;
55
56 /* Create a task for delivering data. */
David Howellsc4028952006-11-22 14:57:56 +000057 INIT_WORK(&queue->immediate, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070058
59 queue->malloced = 0;
60}
61
62/* Release the memory associated with an SCTP inqueue. */
63void sctp_inq_free(struct sctp_inq *queue)
64{
David S. Miller79af02c2005-07-08 21:47:49 -070065 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
67 /* Empty the queue. */
David S. Miller79af02c2005-07-08 21:47:49 -070068 list_for_each_entry_safe(chunk, tmp, &queue->in_chunk_list, list) {
69 list_del_init(&chunk->list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 sctp_chunk_free(chunk);
David S. Miller79af02c2005-07-08 21:47:49 -070071 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070072
73 /* If there is a packet which is currently being worked on,
74 * free it as well.
75 */
Sridhar Samudrala7a48f922006-01-17 11:51:28 -080076 if (queue->in_progress) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070077 sctp_chunk_free(queue->in_progress);
Sridhar Samudrala7a48f922006-01-17 11:51:28 -080078 queue->in_progress = NULL;
79 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070080
81 if (queue->malloced) {
82 /* Dump the master memory segment. */
83 kfree(queue);
84 }
85}
86
87/* Put a new packet in an SCTP inqueue.
88 * We assume that packet->sctp_hdr is set and in host byte order.
89 */
Sridhar Samudralaac0b0462006-08-22 00:15:33 -070090void sctp_inq_push(struct sctp_inq *q, struct sctp_chunk *chunk)
Linus Torvalds1da177e2005-04-16 15:20:36 -070091{
92 /* Directly call the packet handling routine. */
Vlad Yasevich027f6e12007-11-07 11:39:27 -050093 if (chunk->rcvr->dead) {
94 sctp_chunk_free(chunk);
95 return;
96 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070097
98 /* We are now calling this either from the soft interrupt
99 * or from the backlog processing.
100 * Eventually, we should clean up inqueue to not rely
101 * on the BH related data structures.
102 */
Sridhar Samudralaac0b0462006-08-22 00:15:33 -0700103 list_add_tail(&chunk->list, &q->in_chunk_list);
David Howellsc4028952006-11-22 14:57:56 +0000104 q->immediate.func(&q->immediate);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105}
106
Vlad Yasevichbbd0d592007-10-03 17:51:34 -0700107/* Peek at the next chunk on the inqeue. */
108struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *queue)
109{
110 struct sctp_chunk *chunk;
111 sctp_chunkhdr_t *ch = NULL;
112
113 chunk = queue->in_progress;
114 /* If there is no more chunks in this packet, say so */
115 if (chunk->singleton ||
116 chunk->end_of_packet ||
117 chunk->pdiscard)
118 return NULL;
119
120 ch = (sctp_chunkhdr_t *)chunk->chunk_end;
121
122 return ch;
123}
124
125
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126/* Extract a chunk from an SCTP inqueue.
127 *
128 * WARNING: If you need to put the chunk on another queue, you need to
129 * make a shallow copy (clone) of it.
130 */
131struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue)
132{
133 struct sctp_chunk *chunk;
134 sctp_chunkhdr_t *ch = NULL;
135
136 /* The assumption is that we are safe to process the chunks
137 * at this time.
138 */
139
140 if ((chunk = queue->in_progress)) {
141 /* There is a packet that we have been working on.
142 * Any post processing work to do before we move on?
143 */
144 if (chunk->singleton ||
145 chunk->end_of_packet ||
146 chunk->pdiscard) {
147 sctp_chunk_free(chunk);
148 chunk = queue->in_progress = NULL;
149 } else {
150 /* Nothing to do. Next chunk in the packet, please. */
151 ch = (sctp_chunkhdr_t *) chunk->chunk_end;
152
153 /* Force chunk->skb->data to chunk->chunk_end. */
154 skb_pull(chunk->skb,
155 chunk->chunk_end - chunk->skb->data);
Vlad Yasevicha09c8382007-09-05 15:53:58 -0400156
157 /* Verify that we have at least chunk headers
158 * worth of buffer left.
159 */
160 if (skb_headlen(chunk->skb) < sizeof(sctp_chunkhdr_t)) {
161 sctp_chunk_free(chunk);
162 chunk = queue->in_progress = NULL;
163 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 }
165 }
166
167 /* Do we need to take the next packet out of the queue to process? */
168 if (!chunk) {
David S. Miller79af02c2005-07-08 21:47:49 -0700169 struct list_head *entry;
170
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 /* Is the queue empty? */
David S. Miller79af02c2005-07-08 21:47:49 -0700172 if (list_empty(&queue->in_chunk_list))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 return NULL;
174
David S. Miller79af02c2005-07-08 21:47:49 -0700175 entry = queue->in_chunk_list.next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 chunk = queue->in_progress =
David S. Miller79af02c2005-07-08 21:47:49 -0700177 list_entry(entry, struct sctp_chunk, list);
178 list_del_init(entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179
180 /* This is the first chunk in the packet. */
181 chunk->singleton = 1;
182 ch = (sctp_chunkhdr_t *) chunk->skb->data;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -0700183 chunk->data_accepted = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 }
185
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900186 chunk->chunk_hdr = ch;
187 chunk->chunk_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188 /* In the unlikely case of an IP reassembly, the skb could be
189 * non-linear. If so, update chunk_end so that it doesn't go past
190 * the skb->tail.
191 */
192 if (unlikely(skb_is_nonlinear(chunk->skb))) {
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700193 if (chunk->chunk_end > skb_tail_pointer(chunk->skb))
194 chunk->chunk_end = skb_tail_pointer(chunk->skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195 }
196 skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t));
197 chunk->subh.v = NULL; /* Subheader is no longer valid. */
198
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700199 if (chunk->chunk_end < skb_tail_pointer(chunk->skb)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 /* This is not a singleton */
201 chunk->singleton = 0;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700202 } else if (chunk->chunk_end > skb_tail_pointer(chunk->skb)) {
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900203 /* RFC 2960, Section 6.10 Bundling
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 *
205 * Partial chunks MUST NOT be placed in an SCTP packet.
206 * If the receiver detects a partial chunk, it MUST drop
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900207 * the chunk.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 *
209 * Since the end of the chunk is past the end of our buffer
210 * (which contains the whole packet, we can freely discard
211 * the whole packet.
212 */
213 sctp_chunk_free(chunk);
214 chunk = queue->in_progress = NULL;
215
216 return NULL;
217 } else {
218 /* We are at the end of the packet, so mark the chunk
219 * in case we need to send a SACK.
220 */
221 chunk->end_of_packet = 1;
222 }
223
224 SCTP_DEBUG_PRINTK("+++sctp_inq_pop+++ chunk %p[%s],"
225 " length %d, skb->len %d\n",chunk,
226 sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)),
227 ntohs(chunk->chunk_hdr->length), chunk->skb->len);
228 return chunk;
229}
230
231/* Set a top-half handler.
232 *
233 * Originally, we the top-half handler was scheduled as a BH. We now
234 * call the handler directly in sctp_inq_push() at a time that
235 * we know we are lock safe.
236 * The intent is that this routine will pull stuff out of the
237 * inqueue and process it.
238 */
David Howellsc4028952006-11-22 14:57:56 +0000239void sctp_inq_set_th_handler(struct sctp_inq *q, work_func_t callback)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700240{
David Howellsc4028952006-11-22 14:57:56 +0000241 INIT_WORK(&q->immediate, callback);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242}
243