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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
Jeff Kirsher4b2f13a2013-12-06 06:28:48 -080027 * along with GNU CC; see the file COPYING. If not, see
28 * <http://www.gnu.org/licenses/>.
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +090029 *
Linus Torvalds1da177e2005-04-16 15:20:36 -070030 * Please send any bug reports or fixes you make to the
31 * email address(es):
Daniel Borkmann91705c62013-07-23 14:51:47 +020032 * lksctp developers <linux-sctp@vger.kernel.org>
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +090033 *
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +090034 * Written or modified by:
Linus Torvalds1da177e2005-04-16 15:20:36 -070035 * La Monte H.P. Yarroll <piggy@acm.org>
36 * Karl Knutson <karl@athena.chicago.il.us>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037 */
38
Joe Perches145ce502010-08-24 13:21:08 +000039#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
40
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#include <net/sctp/sctp.h>
42#include <net/sctp/sm.h>
43#include <linux/interrupt.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090044#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
46/* Initialize an SCTP inqueue. */
47void sctp_inq_init(struct sctp_inq *queue)
48{
David S. Miller79af02c2005-07-08 21:47:49 -070049 INIT_LIST_HEAD(&queue->in_chunk_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070050 queue->in_progress = NULL;
51
52 /* Create a task for delivering data. */
David Howellsc4028952006-11-22 14:57:56 +000053 INIT_WORK(&queue->immediate, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070054}
55
56/* Release the memory associated with an SCTP inqueue. */
57void sctp_inq_free(struct sctp_inq *queue)
58{
David S. Miller79af02c2005-07-08 21:47:49 -070059 struct sctp_chunk *chunk, *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -070060
61 /* Empty the queue. */
David S. Miller79af02c2005-07-08 21:47:49 -070062 list_for_each_entry_safe(chunk, tmp, &queue->in_chunk_list, list) {
63 list_del_init(&chunk->list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070064 sctp_chunk_free(chunk);
David S. Miller79af02c2005-07-08 21:47:49 -070065 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070066
67 /* If there is a packet which is currently being worked on,
68 * free it as well.
69 */
Sridhar Samudrala7a48f922006-01-17 11:51:28 -080070 if (queue->in_progress) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 sctp_chunk_free(queue->in_progress);
Sridhar Samudrala7a48f922006-01-17 11:51:28 -080072 queue->in_progress = NULL;
73 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070074}
75
76/* Put a new packet in an SCTP inqueue.
77 * We assume that packet->sctp_hdr is set and in host byte order.
78 */
Sridhar Samudralaac0b0462006-08-22 00:15:33 -070079void sctp_inq_push(struct sctp_inq *q, struct sctp_chunk *chunk)
Linus Torvalds1da177e2005-04-16 15:20:36 -070080{
81 /* Directly call the packet handling routine. */
Vlad Yasevich027f6e12007-11-07 11:39:27 -050082 if (chunk->rcvr->dead) {
83 sctp_chunk_free(chunk);
84 return;
85 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
87 /* We are now calling this either from the soft interrupt
88 * or from the backlog processing.
89 * Eventually, we should clean up inqueue to not rely
90 * on the BH related data structures.
91 */
Sridhar Samudralaac0b0462006-08-22 00:15:33 -070092 list_add_tail(&chunk->list, &q->in_chunk_list);
Michele Baldessari196d6752012-12-01 04:49:42 +000093 if (chunk->asoc)
94 chunk->asoc->stats.ipackets++;
David Howellsc4028952006-11-22 14:57:56 +000095 q->immediate.func(&q->immediate);
Linus Torvalds1da177e2005-04-16 15:20:36 -070096}
97
Vlad Yasevichbbd0d592007-10-03 17:51:34 -070098/* Peek at the next chunk on the inqeue. */
99struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *queue)
100{
101 struct sctp_chunk *chunk;
102 sctp_chunkhdr_t *ch = NULL;
103
104 chunk = queue->in_progress;
105 /* If there is no more chunks in this packet, say so */
106 if (chunk->singleton ||
107 chunk->end_of_packet ||
108 chunk->pdiscard)
109 return NULL;
110
111 ch = (sctp_chunkhdr_t *)chunk->chunk_end;
112
113 return ch;
114}
115
116
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117/* Extract a chunk from an SCTP inqueue.
118 *
119 * WARNING: If you need to put the chunk on another queue, you need to
120 * make a shallow copy (clone) of it.
121 */
122struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue)
123{
124 struct sctp_chunk *chunk;
125 sctp_chunkhdr_t *ch = NULL;
126
127 /* The assumption is that we are safe to process the chunks
128 * at this time.
129 */
130
131 if ((chunk = queue->in_progress)) {
132 /* There is a packet that we have been working on.
133 * Any post processing work to do before we move on?
134 */
135 if (chunk->singleton ||
136 chunk->end_of_packet ||
137 chunk->pdiscard) {
138 sctp_chunk_free(chunk);
139 chunk = queue->in_progress = NULL;
140 } else {
141 /* Nothing to do. Next chunk in the packet, please. */
142 ch = (sctp_chunkhdr_t *) chunk->chunk_end;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 /* Force chunk->skb->data to chunk->chunk_end. */
Daniel Borkmann26b87c72014-10-09 22:55:33 +0200144 skb_pull(chunk->skb, chunk->chunk_end - chunk->skb->data);
145 /* We are guaranteed to pull a SCTP header. */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 }
147 }
148
149 /* Do we need to take the next packet out of the queue to process? */
150 if (!chunk) {
David S. Miller79af02c2005-07-08 21:47:49 -0700151 struct list_head *entry;
152
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 /* Is the queue empty? */
David S. Miller79af02c2005-07-08 21:47:49 -0700154 if (list_empty(&queue->in_chunk_list))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 return NULL;
156
David S. Miller79af02c2005-07-08 21:47:49 -0700157 entry = queue->in_chunk_list.next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 chunk = queue->in_progress =
David S. Miller79af02c2005-07-08 21:47:49 -0700159 list_entry(entry, struct sctp_chunk, list);
160 list_del_init(entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700161
162 /* This is the first chunk in the packet. */
163 chunk->singleton = 1;
164 ch = (sctp_chunkhdr_t *) chunk->skb->data;
Neil Horman7c3ceb4f2006-05-05 17:02:09 -0700165 chunk->data_accepted = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700166 }
167
YOSHIFUJI Hideakid808ad92007-02-09 23:25:18 +0900168 chunk->chunk_hdr = ch;
169 chunk->chunk_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 /* In the unlikely case of an IP reassembly, the skb could be
171 * non-linear. If so, update chunk_end so that it doesn't go past
172 * the skb->tail.
173 */
174 if (unlikely(skb_is_nonlinear(chunk->skb))) {
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700175 if (chunk->chunk_end > skb_tail_pointer(chunk->skb))
176 chunk->chunk_end = skb_tail_pointer(chunk->skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 }
178 skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t));
179 chunk->subh.v = NULL; /* Subheader is no longer valid. */
180
Daniel Borkmann26b87c72014-10-09 22:55:33 +0200181 if (chunk->chunk_end + sizeof(sctp_chunkhdr_t) <
182 skb_tail_pointer(chunk->skb)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700183 /* This is not a singleton */
184 chunk->singleton = 0;
Arnaldo Carvalho de Melo27a884d2007-04-19 20:29:13 -0700185 } else if (chunk->chunk_end > skb_tail_pointer(chunk->skb)) {
Daniel Borkmann26b87c72014-10-09 22:55:33 +0200186 /* Discard inside state machine. */
187 chunk->pdiscard = 1;
188 chunk->chunk_end = skb_tail_pointer(chunk->skb);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700189 } else {
190 /* We are at the end of the packet, so mark the chunk
191 * in case we need to send a SACK.
192 */
193 chunk->end_of_packet = 1;
194 }
195
Daniel Borkmannbb333812013-06-28 19:49:40 +0200196 pr_debug("+++sctp_inq_pop+++ chunk:%p[%s], length:%d, skb->len:%d\n",
197 chunk, sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)),
198 ntohs(chunk->chunk_hdr->length), chunk->skb->len);
199
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200 return chunk;
201}
202
203/* Set a top-half handler.
204 *
205 * Originally, we the top-half handler was scheduled as a BH. We now
206 * call the handler directly in sctp_inq_push() at a time that
207 * we know we are lock safe.
208 * The intent is that this routine will pull stuff out of the
209 * inqueue and process it.
210 */
David Howellsc4028952006-11-22 14:57:56 +0000211void sctp_inq_set_th_handler(struct sctp_inq *q, work_func_t callback)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212{
David Howellsc4028952006-11-22 14:57:56 +0000213 INIT_WORK(&q->immediate, callback);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214}