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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): | |
91705c61 | 33 | * lksctp developers <linux-sctp@vger.kernel.org> |
d808ad9a | 34 | * |
d808ad9a | 35 | * Written or modified by: |
1da177e4 LT |
36 | * La Monte H.P. Yarroll <piggy@acm.org> |
37 | * Karl Knutson <karl@athena.chicago.il.us> | |
1da177e4 LT |
38 | */ |
39 | ||
145ce502 JP |
40 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
41 | ||
1da177e4 LT |
42 | #include <net/sctp/sctp.h> |
43 | #include <net/sctp/sm.h> | |
44 | #include <linux/interrupt.h> | |
5a0e3ad6 | 45 | #include <linux/slab.h> |
1da177e4 LT |
46 | |
47 | /* Initialize an SCTP inqueue. */ | |
48 | void sctp_inq_init(struct sctp_inq *queue) | |
49 | { | |
79af02c2 | 50 | INIT_LIST_HEAD(&queue->in_chunk_list); |
1da177e4 LT |
51 | queue->in_progress = NULL; |
52 | ||
53 | /* Create a task for delivering data. */ | |
c4028958 | 54 | INIT_WORK(&queue->immediate, NULL); |
1da177e4 LT |
55 | } |
56 | ||
57 | /* Release the memory associated with an SCTP inqueue. */ | |
58 | void sctp_inq_free(struct sctp_inq *queue) | |
59 | { | |
79af02c2 | 60 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
61 | |
62 | /* Empty the queue. */ | |
79af02c2 DM |
63 | list_for_each_entry_safe(chunk, tmp, &queue->in_chunk_list, list) { |
64 | list_del_init(&chunk->list); | |
1da177e4 | 65 | sctp_chunk_free(chunk); |
79af02c2 | 66 | } |
1da177e4 LT |
67 | |
68 | /* If there is a packet which is currently being worked on, | |
69 | * free it as well. | |
70 | */ | |
7a48f923 | 71 | if (queue->in_progress) { |
1da177e4 | 72 | sctp_chunk_free(queue->in_progress); |
7a48f923 SS |
73 | queue->in_progress = NULL; |
74 | } | |
1da177e4 LT |
75 | } |
76 | ||
77 | /* Put a new packet in an SCTP inqueue. | |
78 | * We assume that packet->sctp_hdr is set and in host byte order. | |
79 | */ | |
ac0b0462 | 80 | void sctp_inq_push(struct sctp_inq *q, struct sctp_chunk *chunk) |
1da177e4 LT |
81 | { |
82 | /* Directly call the packet handling routine. */ | |
027f6e1a VY |
83 | if (chunk->rcvr->dead) { |
84 | sctp_chunk_free(chunk); | |
85 | return; | |
86 | } | |
1da177e4 LT |
87 | |
88 | /* We are now calling this either from the soft interrupt | |
89 | * or from the backlog processing. | |
90 | * Eventually, we should clean up inqueue to not rely | |
91 | * on the BH related data structures. | |
92 | */ | |
ac0b0462 | 93 | list_add_tail(&chunk->list, &q->in_chunk_list); |
196d6759 MB |
94 | if (chunk->asoc) |
95 | chunk->asoc->stats.ipackets++; | |
c4028958 | 96 | q->immediate.func(&q->immediate); |
1da177e4 LT |
97 | } |
98 | ||
bbd0d598 VY |
99 | /* Peek at the next chunk on the inqeue. */ |
100 | struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *queue) | |
101 | { | |
102 | struct sctp_chunk *chunk; | |
103 | sctp_chunkhdr_t *ch = NULL; | |
104 | ||
105 | chunk = queue->in_progress; | |
106 | /* If there is no more chunks in this packet, say so */ | |
107 | if (chunk->singleton || | |
108 | chunk->end_of_packet || | |
109 | chunk->pdiscard) | |
110 | return NULL; | |
111 | ||
112 | ch = (sctp_chunkhdr_t *)chunk->chunk_end; | |
113 | ||
114 | return ch; | |
115 | } | |
116 | ||
117 | ||
1da177e4 LT |
118 | /* Extract a chunk from an SCTP inqueue. |
119 | * | |
120 | * WARNING: If you need to put the chunk on another queue, you need to | |
121 | * make a shallow copy (clone) of it. | |
122 | */ | |
123 | struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue) | |
124 | { | |
125 | struct sctp_chunk *chunk; | |
126 | sctp_chunkhdr_t *ch = NULL; | |
127 | ||
128 | /* The assumption is that we are safe to process the chunks | |
129 | * at this time. | |
130 | */ | |
131 | ||
132 | if ((chunk = queue->in_progress)) { | |
133 | /* There is a packet that we have been working on. | |
134 | * Any post processing work to do before we move on? | |
135 | */ | |
136 | if (chunk->singleton || | |
137 | chunk->end_of_packet || | |
138 | chunk->pdiscard) { | |
139 | sctp_chunk_free(chunk); | |
140 | chunk = queue->in_progress = NULL; | |
141 | } else { | |
142 | /* Nothing to do. Next chunk in the packet, please. */ | |
143 | ch = (sctp_chunkhdr_t *) chunk->chunk_end; | |
144 | ||
145 | /* Force chunk->skb->data to chunk->chunk_end. */ | |
146 | skb_pull(chunk->skb, | |
147 | chunk->chunk_end - chunk->skb->data); | |
a09c8384 VY |
148 | |
149 | /* Verify that we have at least chunk headers | |
150 | * worth of buffer left. | |
151 | */ | |
152 | if (skb_headlen(chunk->skb) < sizeof(sctp_chunkhdr_t)) { | |
153 | sctp_chunk_free(chunk); | |
154 | chunk = queue->in_progress = NULL; | |
155 | } | |
1da177e4 LT |
156 | } |
157 | } | |
158 | ||
159 | /* Do we need to take the next packet out of the queue to process? */ | |
160 | if (!chunk) { | |
79af02c2 DM |
161 | struct list_head *entry; |
162 | ||
1da177e4 | 163 | /* Is the queue empty? */ |
79af02c2 | 164 | if (list_empty(&queue->in_chunk_list)) |
1da177e4 LT |
165 | return NULL; |
166 | ||
79af02c2 | 167 | entry = queue->in_chunk_list.next; |
1da177e4 | 168 | chunk = queue->in_progress = |
79af02c2 DM |
169 | list_entry(entry, struct sctp_chunk, list); |
170 | list_del_init(entry); | |
1da177e4 LT |
171 | |
172 | /* This is the first chunk in the packet. */ | |
173 | chunk->singleton = 1; | |
174 | ch = (sctp_chunkhdr_t *) chunk->skb->data; | |
7c3ceb4f | 175 | chunk->data_accepted = 0; |
1da177e4 LT |
176 | } |
177 | ||
d808ad9a YH |
178 | chunk->chunk_hdr = ch; |
179 | chunk->chunk_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length)); | |
1da177e4 LT |
180 | /* In the unlikely case of an IP reassembly, the skb could be |
181 | * non-linear. If so, update chunk_end so that it doesn't go past | |
182 | * the skb->tail. | |
183 | */ | |
184 | if (unlikely(skb_is_nonlinear(chunk->skb))) { | |
27a884dc ACM |
185 | if (chunk->chunk_end > skb_tail_pointer(chunk->skb)) |
186 | chunk->chunk_end = skb_tail_pointer(chunk->skb); | |
1da177e4 LT |
187 | } |
188 | skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t)); | |
189 | chunk->subh.v = NULL; /* Subheader is no longer valid. */ | |
190 | ||
27a884dc | 191 | if (chunk->chunk_end < skb_tail_pointer(chunk->skb)) { |
1da177e4 LT |
192 | /* This is not a singleton */ |
193 | chunk->singleton = 0; | |
27a884dc | 194 | } else if (chunk->chunk_end > skb_tail_pointer(chunk->skb)) { |
d808ad9a | 195 | /* RFC 2960, Section 6.10 Bundling |
1da177e4 LT |
196 | * |
197 | * Partial chunks MUST NOT be placed in an SCTP packet. | |
198 | * If the receiver detects a partial chunk, it MUST drop | |
d808ad9a | 199 | * the chunk. |
1da177e4 LT |
200 | * |
201 | * Since the end of the chunk is past the end of our buffer | |
202 | * (which contains the whole packet, we can freely discard | |
203 | * the whole packet. | |
204 | */ | |
205 | sctp_chunk_free(chunk); | |
206 | chunk = queue->in_progress = NULL; | |
207 | ||
208 | return NULL; | |
209 | } else { | |
210 | /* We are at the end of the packet, so mark the chunk | |
211 | * in case we need to send a SACK. | |
212 | */ | |
213 | chunk->end_of_packet = 1; | |
214 | } | |
215 | ||
bb33381d DB |
216 | pr_debug("+++sctp_inq_pop+++ chunk:%p[%s], length:%d, skb->len:%d\n", |
217 | chunk, sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)), | |
218 | ntohs(chunk->chunk_hdr->length), chunk->skb->len); | |
219 | ||
1da177e4 LT |
220 | return chunk; |
221 | } | |
222 | ||
223 | /* Set a top-half handler. | |
224 | * | |
225 | * Originally, we the top-half handler was scheduled as a BH. We now | |
226 | * call the handler directly in sctp_inq_push() at a time that | |
227 | * we know we are lock safe. | |
228 | * The intent is that this routine will pull stuff out of the | |
229 | * inqueue and process it. | |
230 | */ | |
c4028958 | 231 | void sctp_inq_set_th_handler(struct sctp_inq *q, work_func_t callback) |
1da177e4 | 232 | { |
c4028958 | 233 | INIT_WORK(&q->immediate, callback); |
1da177e4 | 234 | } |