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60c778b2 | 1 | /* SCTP kernel implementation |
1da177e4 LT |
2 | * Copyright (c) 1999-2000 Cisco, Inc. |
3 | * Copyright (c) 1999-2001 Motorola, Inc. | |
4 | * Copyright (c) 2002 International Business Machines, Corp. | |
d808ad9a | 5 | * |
60c778b2 | 6 | * This file is part of the SCTP kernel implementation |
d808ad9a | 7 | * |
1da177e4 LT |
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. | |
d808ad9a | 13 | * |
60c778b2 | 14 | * This SCTP implementation is free software; |
d808ad9a | 15 | * you can redistribute it and/or modify it under the terms of |
1da177e4 LT |
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. | |
d808ad9a | 19 | * |
60c778b2 | 20 | * This SCTP implementation is distributed in the hope that it |
1da177e4 LT |
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. | |
d808ad9a | 25 | * |
1da177e4 LT |
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, | |
d808ad9a YH |
29 | * Boston, MA 02111-1307, USA. |
30 | * | |
1da177e4 LT |
31 | * Please send any bug reports or fixes you make to the |
32 | * email address(es): | |
33 | * lksctp developers <lksctp-developers@lists.sourceforge.net> | |
d808ad9a | 34 | * |
1da177e4 LT |
35 | * Or submit a bug report through the following website: |
36 | * http://www.sf.net/projects/lksctp | |
37 | * | |
d808ad9a | 38 | * Written or modified by: |
1da177e4 LT |
39 | * La Monte H.P. Yarroll <piggy@acm.org> |
40 | * Karl Knutson <karl@athena.chicago.il.us> | |
d808ad9a | 41 | * |
1da177e4 LT |
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. */ | |
c4028958 | 57 | INIT_WORK(&queue->immediate, NULL); |
1da177e4 LT |
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 | */ | |
7a48f923 | 76 | if (queue->in_progress) { |
1da177e4 | 77 | sctp_chunk_free(queue->in_progress); |
7a48f923 SS |
78 | queue->in_progress = NULL; |
79 | } | |
1da177e4 LT |
80 | |
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 | */ | |
ac0b0462 | 90 | void sctp_inq_push(struct sctp_inq *q, struct sctp_chunk *chunk) |
1da177e4 LT |
91 | { |
92 | /* Directly call the packet handling routine. */ | |
027f6e1a VY |
93 | if (chunk->rcvr->dead) { |
94 | sctp_chunk_free(chunk); | |
95 | return; | |
96 | } | |
1da177e4 LT |
97 | |
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 | */ | |
ac0b0462 | 103 | list_add_tail(&chunk->list, &q->in_chunk_list); |
c4028958 | 104 | q->immediate.func(&q->immediate); |
1da177e4 LT |
105 | } |
106 | ||
bbd0d598 VY |
107 | /* Peek at the next chunk on the inqeue. */ |
108 | struct 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 | ||
1da177e4 LT |
126 | /* 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 | */ | |
131 | struct 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); | |
a09c8384 VY |
156 | |
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 | } | |
1da177e4 LT |
164 | } |
165 | } | |
166 | ||
167 | /* Do we need to take the next packet out of the queue to process? */ | |
168 | if (!chunk) { | |
79af02c2 DM |
169 | struct list_head *entry; |
170 | ||
1da177e4 | 171 | /* Is the queue empty? */ |
79af02c2 | 172 | if (list_empty(&queue->in_chunk_list)) |
1da177e4 LT |
173 | return NULL; |
174 | ||
79af02c2 | 175 | entry = queue->in_chunk_list.next; |
1da177e4 | 176 | chunk = queue->in_progress = |
79af02c2 DM |
177 | list_entry(entry, struct sctp_chunk, list); |
178 | list_del_init(entry); | |
1da177e4 LT |
179 | |
180 | /* This is the first chunk in the packet. */ | |
181 | chunk->singleton = 1; | |
182 | ch = (sctp_chunkhdr_t *) chunk->skb->data; | |
7c3ceb4f | 183 | chunk->data_accepted = 0; |
1da177e4 LT |
184 | } |
185 | ||
d808ad9a YH |
186 | chunk->chunk_hdr = ch; |
187 | chunk->chunk_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length)); | |
1da177e4 LT |
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 | |
190 | * the skb->tail. | |
191 | */ | |
192 | if (unlikely(skb_is_nonlinear(chunk->skb))) { | |
27a884dc ACM |
193 | if (chunk->chunk_end > skb_tail_pointer(chunk->skb)) |
194 | chunk->chunk_end = skb_tail_pointer(chunk->skb); | |
1da177e4 LT |
195 | } |
196 | skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t)); | |
197 | chunk->subh.v = NULL; /* Subheader is no longer valid. */ | |
198 | ||
27a884dc | 199 | if (chunk->chunk_end < skb_tail_pointer(chunk->skb)) { |
1da177e4 LT |
200 | /* This is not a singleton */ |
201 | chunk->singleton = 0; | |
27a884dc | 202 | } else if (chunk->chunk_end > skb_tail_pointer(chunk->skb)) { |
d808ad9a | 203 | /* RFC 2960, Section 6.10 Bundling |
1da177e4 LT |
204 | * |
205 | * Partial chunks MUST NOT be placed in an SCTP packet. | |
206 | * If the receiver detects a partial chunk, it MUST drop | |
d808ad9a | 207 | * the chunk. |
1da177e4 LT |
208 | * |
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 | */ | |
c4028958 | 239 | void sctp_inq_set_th_handler(struct sctp_inq *q, work_func_t callback) |
1da177e4 | 240 | { |
c4028958 | 241 | INIT_WORK(&q->immediate, callback); |
1da177e4 LT |
242 | } |
243 |