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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 | */ | |
45 | ||
46 | #include <net/sctp/sctp.h> | |
47 | #include <net/sctp/sm.h> | |
48 | #include <linux/interrupt.h> | |
49 | ||
50 | /* Initialize an SCTP inqueue. */ | |
51 | void sctp_inq_init(struct sctp_inq *queue) | |
52 | { | |
79af02c2 | 53 | INIT_LIST_HEAD(&queue->in_chunk_list); |
1da177e4 LT |
54 | queue->in_progress = NULL; |
55 | ||
56 | /* Create a task for delivering data. */ | |
57 | INIT_WORK(&queue->immediate, NULL, NULL); | |
58 | ||
59 | queue->malloced = 0; | |
60 | } | |
61 | ||
62 | /* Release the memory associated with an SCTP inqueue. */ | |
63 | void sctp_inq_free(struct sctp_inq *queue) | |
64 | { | |
79af02c2 | 65 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
66 | |
67 | /* Empty the queue. */ | |
79af02c2 DM |
68 | list_for_each_entry_safe(chunk, tmp, &queue->in_chunk_list, list) { |
69 | list_del_init(&chunk->list); | |
1da177e4 | 70 | sctp_chunk_free(chunk); |
79af02c2 | 71 | } |
1da177e4 LT |
72 | |
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 | ||
79 | if (queue->malloced) { | |
80 | /* Dump the master memory segment. */ | |
81 | kfree(queue); | |
82 | } | |
83 | } | |
84 | ||
85 | /* Put a new packet in an SCTP inqueue. | |
86 | * We assume that packet->sctp_hdr is set and in host byte order. | |
87 | */ | |
88 | void sctp_inq_push(struct sctp_inq *q, struct sctp_chunk *packet) | |
89 | { | |
90 | /* Directly call the packet handling routine. */ | |
91 | ||
92 | /* We are now calling this either from the soft interrupt | |
93 | * or from the backlog processing. | |
94 | * Eventually, we should clean up inqueue to not rely | |
95 | * on the BH related data structures. | |
96 | */ | |
79af02c2 | 97 | list_add_tail(&packet->list, &q->in_chunk_list); |
1da177e4 LT |
98 | q->immediate.func(q->immediate.data); |
99 | } | |
100 | ||
101 | /* Extract a chunk from an SCTP inqueue. | |
102 | * | |
103 | * WARNING: If you need to put the chunk on another queue, you need to | |
104 | * make a shallow copy (clone) of it. | |
105 | */ | |
106 | struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue) | |
107 | { | |
108 | struct sctp_chunk *chunk; | |
109 | sctp_chunkhdr_t *ch = NULL; | |
110 | ||
111 | /* The assumption is that we are safe to process the chunks | |
112 | * at this time. | |
113 | */ | |
114 | ||
115 | if ((chunk = queue->in_progress)) { | |
116 | /* There is a packet that we have been working on. | |
117 | * Any post processing work to do before we move on? | |
118 | */ | |
119 | if (chunk->singleton || | |
120 | chunk->end_of_packet || | |
121 | chunk->pdiscard) { | |
122 | sctp_chunk_free(chunk); | |
123 | chunk = queue->in_progress = NULL; | |
124 | } else { | |
125 | /* Nothing to do. Next chunk in the packet, please. */ | |
126 | ch = (sctp_chunkhdr_t *) chunk->chunk_end; | |
127 | ||
128 | /* Force chunk->skb->data to chunk->chunk_end. */ | |
129 | skb_pull(chunk->skb, | |
130 | chunk->chunk_end - chunk->skb->data); | |
131 | } | |
132 | } | |
133 | ||
134 | /* Do we need to take the next packet out of the queue to process? */ | |
135 | if (!chunk) { | |
79af02c2 DM |
136 | struct list_head *entry; |
137 | ||
1da177e4 | 138 | /* Is the queue empty? */ |
79af02c2 | 139 | if (list_empty(&queue->in_chunk_list)) |
1da177e4 LT |
140 | return NULL; |
141 | ||
79af02c2 | 142 | entry = queue->in_chunk_list.next; |
1da177e4 | 143 | chunk = queue->in_progress = |
79af02c2 DM |
144 | list_entry(entry, struct sctp_chunk, list); |
145 | list_del_init(entry); | |
1da177e4 LT |
146 | |
147 | /* This is the first chunk in the packet. */ | |
148 | chunk->singleton = 1; | |
149 | ch = (sctp_chunkhdr_t *) chunk->skb->data; | |
150 | } | |
151 | ||
152 | chunk->chunk_hdr = ch; | |
153 | chunk->chunk_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length)); | |
154 | /* In the unlikely case of an IP reassembly, the skb could be | |
155 | * non-linear. If so, update chunk_end so that it doesn't go past | |
156 | * the skb->tail. | |
157 | */ | |
158 | if (unlikely(skb_is_nonlinear(chunk->skb))) { | |
159 | if (chunk->chunk_end > chunk->skb->tail) | |
160 | chunk->chunk_end = chunk->skb->tail; | |
161 | } | |
162 | skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t)); | |
163 | chunk->subh.v = NULL; /* Subheader is no longer valid. */ | |
164 | ||
165 | if (chunk->chunk_end < chunk->skb->tail) { | |
166 | /* This is not a singleton */ | |
167 | chunk->singleton = 0; | |
168 | } else if (chunk->chunk_end > chunk->skb->tail) { | |
169 | /* RFC 2960, Section 6.10 Bundling | |
170 | * | |
171 | * Partial chunks MUST NOT be placed in an SCTP packet. | |
172 | * If the receiver detects a partial chunk, it MUST drop | |
173 | * the chunk. | |
174 | * | |
175 | * Since the end of the chunk is past the end of our buffer | |
176 | * (which contains the whole packet, we can freely discard | |
177 | * the whole packet. | |
178 | */ | |
179 | sctp_chunk_free(chunk); | |
180 | chunk = queue->in_progress = NULL; | |
181 | ||
182 | return NULL; | |
183 | } else { | |
184 | /* We are at the end of the packet, so mark the chunk | |
185 | * in case we need to send a SACK. | |
186 | */ | |
187 | chunk->end_of_packet = 1; | |
188 | } | |
189 | ||
190 | SCTP_DEBUG_PRINTK("+++sctp_inq_pop+++ chunk %p[%s]," | |
191 | " length %d, skb->len %d\n",chunk, | |
192 | sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)), | |
193 | ntohs(chunk->chunk_hdr->length), chunk->skb->len); | |
194 | return chunk; | |
195 | } | |
196 | ||
197 | /* Set a top-half handler. | |
198 | * | |
199 | * Originally, we the top-half handler was scheduled as a BH. We now | |
200 | * call the handler directly in sctp_inq_push() at a time that | |
201 | * we know we are lock safe. | |
202 | * The intent is that this routine will pull stuff out of the | |
203 | * inqueue and process it. | |
204 | */ | |
205 | void sctp_inq_set_th_handler(struct sctp_inq *q, | |
206 | void (*callback)(void *), void *arg) | |
207 | { | |
208 | INIT_WORK(&q->immediate, callback, arg); | |
209 | } | |
210 |