1 /* SCTP kernel implementation
2 * Copyright (c) 1999-2000 Cisco, Inc.
3 * Copyright (c) 1999-2001 Motorola, Inc.
4 * Copyright (c) 2002 International Business Machines, Corp.
6 * This file is part of the SCTP kernel implementation
8 * These functions are the methods for accessing the SCTP inqueue.
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.
14 * This SCTP 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)
20 * This SCTP 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.
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.
31 * Please send any bug reports or fixes you make to the
33 * lksctp developers <lksctp-developers@lists.sourceforge.net>
35 * Or submit a bug report through the following website:
36 * http://www.sf.net/projects/lksctp
38 * Written or modified by:
39 * La Monte H.P. Yarroll <piggy@acm.org>
40 * Karl Knutson <karl@athena.chicago.il.us>
42 * Any bugs reported given to us we will try to fix... any fixes shared will
43 * be incorporated into the next SCTP release.
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)
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);
62 /* Release the memory associated with an SCTP inqueue. */
63 void sctp_inq_free(struct sctp_inq *queue)
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);
73 /* If there is a packet which is currently being worked on,
76 if (queue->in_progress) {
77 sctp_chunk_free(queue->in_progress);
78 queue->in_progress = NULL;
81 if (queue->malloced) {
82 /* Dump the master memory segment. */
87 /* Put a new packet in an SCTP inqueue.
88 * We assume that packet->sctp_hdr is set and in host byte order.
90 void sctp_inq_push(struct sctp_inq *q, struct sctp_chunk *chunk)
92 /* Directly call the packet handling routine. */
93 if (chunk->rcvr->dead) {
94 sctp_chunk_free(chunk);
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.
103 list_add_tail(&chunk->list, &q->in_chunk_list);
104 q->immediate.func(&q->immediate);
107 /* Peek at the next chunk on the inqeue. */
108 struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *queue)
110 struct sctp_chunk *chunk;
111 sctp_chunkhdr_t *ch = NULL;
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 ||
120 ch = (sctp_chunkhdr_t *)chunk->chunk_end;
126 /* Extract a chunk from an SCTP inqueue.
128 * WARNING: If you need to put the chunk on another queue, you need to
129 * make a shallow copy (clone) of it.
131 struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue)
133 struct sctp_chunk *chunk;
134 sctp_chunkhdr_t *ch = NULL;
136 /* The assumption is that we are safe to process the chunks
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?
144 if (chunk->singleton ||
145 chunk->end_of_packet ||
147 sctp_chunk_free(chunk);
148 chunk = queue->in_progress = NULL;
150 /* Nothing to do. Next chunk in the packet, please. */
151 ch = (sctp_chunkhdr_t *) chunk->chunk_end;
153 /* Force chunk->skb->data to chunk->chunk_end. */
155 chunk->chunk_end - chunk->skb->data);
157 /* Verify that we have at least chunk headers
158 * worth of buffer left.
160 if (skb_headlen(chunk->skb) < sizeof(sctp_chunkhdr_t)) {
161 sctp_chunk_free(chunk);
162 chunk = queue->in_progress = NULL;
167 /* Do we need to take the next packet out of the queue to process? */
169 struct list_head *entry;
171 /* Is the queue empty? */
172 if (list_empty(&queue->in_chunk_list))
175 entry = queue->in_chunk_list.next;
176 chunk = queue->in_progress =
177 list_entry(entry, struct sctp_chunk, list);
178 list_del_init(entry);
180 /* This is the first chunk in the packet. */
181 chunk->singleton = 1;
182 ch = (sctp_chunkhdr_t *) chunk->skb->data;
183 chunk->data_accepted = 0;
186 chunk->chunk_hdr = ch;
187 chunk->chunk_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
188 /* 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
192 if (unlikely(skb_is_nonlinear(chunk->skb))) {
193 if (chunk->chunk_end > skb_tail_pointer(chunk->skb))
194 chunk->chunk_end = skb_tail_pointer(chunk->skb);
196 skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t));
197 chunk->subh.v = NULL; /* Subheader is no longer valid. */
199 if (chunk->chunk_end < skb_tail_pointer(chunk->skb)) {
200 /* This is not a singleton */
201 chunk->singleton = 0;
202 } else if (chunk->chunk_end > skb_tail_pointer(chunk->skb)) {
203 /* RFC 2960, Section 6.10 Bundling
205 * Partial chunks MUST NOT be placed in an SCTP packet.
206 * If the receiver detects a partial chunk, it MUST drop
209 * Since the end of the chunk is past the end of our buffer
210 * (which contains the whole packet, we can freely discard
213 sctp_chunk_free(chunk);
214 chunk = queue->in_progress = NULL;
218 /* We are at the end of the packet, so mark the chunk
219 * in case we need to send a SACK.
221 chunk->end_of_packet = 1;
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);
231 /* Set a top-half handler.
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.
239 void sctp_inq_set_th_handler(struct sctp_inq *q, work_func_t callback)
241 INIT_WORK(&q->immediate, callback);