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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 | 26 | * You should have received a copy of the GNU General Public License |
4b2f13a2 JK |
27 | * along with GNU CC; see the file COPYING. If not, see |
28 | * <http://www.gnu.org/licenses/>. | |
d808ad9a | 29 | * |
1da177e4 LT |
30 | * Please send any bug reports or fixes you make to the |
31 | * email address(es): | |
91705c61 | 32 | * lksctp developers <linux-sctp@vger.kernel.org> |
d808ad9a | 33 | * |
d808ad9a | 34 | * Written or modified by: |
1da177e4 LT |
35 | * La Monte H.P. Yarroll <piggy@acm.org> |
36 | * Karl Knutson <karl@athena.chicago.il.us> | |
1da177e4 LT |
37 | */ |
38 | ||
145ce502 JP |
39 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
40 | ||
1da177e4 LT |
41 | #include <net/sctp/sctp.h> |
42 | #include <net/sctp/sm.h> | |
43 | #include <linux/interrupt.h> | |
5a0e3ad6 | 44 | #include <linux/slab.h> |
1da177e4 LT |
45 | |
46 | /* Initialize an SCTP inqueue. */ | |
47 | void sctp_inq_init(struct sctp_inq *queue) | |
48 | { | |
79af02c2 | 49 | INIT_LIST_HEAD(&queue->in_chunk_list); |
1da177e4 LT |
50 | queue->in_progress = NULL; |
51 | ||
52 | /* Create a task for delivering data. */ | |
c4028958 | 53 | INIT_WORK(&queue->immediate, NULL); |
1da177e4 LT |
54 | } |
55 | ||
56 | /* Release the memory associated with an SCTP inqueue. */ | |
57 | void sctp_inq_free(struct sctp_inq *queue) | |
58 | { | |
79af02c2 | 59 | struct sctp_chunk *chunk, *tmp; |
1da177e4 LT |
60 | |
61 | /* Empty the queue. */ | |
79af02c2 DM |
62 | list_for_each_entry_safe(chunk, tmp, &queue->in_chunk_list, list) { |
63 | list_del_init(&chunk->list); | |
1da177e4 | 64 | sctp_chunk_free(chunk); |
79af02c2 | 65 | } |
1da177e4 LT |
66 | |
67 | /* If there is a packet which is currently being worked on, | |
68 | * free it as well. | |
69 | */ | |
7a48f923 | 70 | if (queue->in_progress) { |
1da177e4 | 71 | sctp_chunk_free(queue->in_progress); |
7a48f923 SS |
72 | queue->in_progress = NULL; |
73 | } | |
1da177e4 LT |
74 | } |
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 | */ | |
ac0b0462 | 79 | void sctp_inq_push(struct sctp_inq *q, struct sctp_chunk *chunk) |
1da177e4 LT |
80 | { |
81 | /* Directly call the packet handling routine. */ | |
027f6e1a VY |
82 | if (chunk->rcvr->dead) { |
83 | sctp_chunk_free(chunk); | |
84 | return; | |
85 | } | |
1da177e4 LT |
86 | |
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 | */ | |
860fbbc3 | 92 | local_bh_disable(); |
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); |
860fbbc3 | 97 | local_bh_enable(); |
1da177e4 LT |
98 | } |
99 | ||
bbd0d598 VY |
100 | /* Peek at the next chunk on the inqeue. */ |
101 | struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *queue) | |
102 | { | |
103 | struct sctp_chunk *chunk; | |
104 | sctp_chunkhdr_t *ch = NULL; | |
105 | ||
106 | chunk = queue->in_progress; | |
107 | /* If there is no more chunks in this packet, say so */ | |
108 | if (chunk->singleton || | |
109 | chunk->end_of_packet || | |
110 | chunk->pdiscard) | |
111 | return NULL; | |
112 | ||
113 | ch = (sctp_chunkhdr_t *)chunk->chunk_end; | |
114 | ||
115 | return ch; | |
116 | } | |
117 | ||
118 | ||
1da177e4 LT |
119 | /* Extract a chunk from an SCTP inqueue. |
120 | * | |
121 | * WARNING: If you need to put the chunk on another queue, you need to | |
122 | * make a shallow copy (clone) of it. | |
123 | */ | |
124 | struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue) | |
125 | { | |
126 | struct sctp_chunk *chunk; | |
127 | sctp_chunkhdr_t *ch = NULL; | |
128 | ||
129 | /* The assumption is that we are safe to process the chunks | |
130 | * at this time. | |
131 | */ | |
132 | ||
3acb50c1 MRL |
133 | chunk = queue->in_progress; |
134 | if (chunk) { | |
1da177e4 LT |
135 | /* There is a packet that we have been working on. |
136 | * Any post processing work to do before we move on? | |
137 | */ | |
138 | if (chunk->singleton || | |
139 | chunk->end_of_packet || | |
140 | chunk->pdiscard) { | |
90017acc MRL |
141 | if (chunk->head_skb == chunk->skb) { |
142 | chunk->skb = skb_shinfo(chunk->skb)->frag_list; | |
143 | goto new_skb; | |
144 | } | |
145 | if (chunk->skb->next) { | |
146 | chunk->skb = chunk->skb->next; | |
147 | goto new_skb; | |
148 | } | |
149 | ||
150 | if (chunk->head_skb) | |
151 | chunk->skb = chunk->head_skb; | |
1da177e4 LT |
152 | sctp_chunk_free(chunk); |
153 | chunk = queue->in_progress = NULL; | |
154 | } else { | |
155 | /* Nothing to do. Next chunk in the packet, please. */ | |
156 | ch = (sctp_chunkhdr_t *) chunk->chunk_end; | |
1da177e4 | 157 | /* Force chunk->skb->data to chunk->chunk_end. */ |
26b87c78 DB |
158 | skb_pull(chunk->skb, chunk->chunk_end - chunk->skb->data); |
159 | /* We are guaranteed to pull a SCTP header. */ | |
1da177e4 LT |
160 | } |
161 | } | |
162 | ||
163 | /* Do we need to take the next packet out of the queue to process? */ | |
164 | if (!chunk) { | |
79af02c2 DM |
165 | struct list_head *entry; |
166 | ||
3acb50c1 | 167 | next_chunk: |
1da177e4 | 168 | /* Is the queue empty? */ |
90017acc MRL |
169 | entry = sctp_list_dequeue(&queue->in_chunk_list); |
170 | if (!entry) | |
1da177e4 LT |
171 | return NULL; |
172 | ||
3acb50c1 | 173 | chunk = list_entry(entry, struct sctp_chunk, list); |
1da177e4 | 174 | |
3acb50c1 | 175 | /* Linearize if it's not GSO */ |
90017acc MRL |
176 | if ((skb_shinfo(chunk->skb)->gso_type & SKB_GSO_SCTP) != SKB_GSO_SCTP && |
177 | skb_is_nonlinear(chunk->skb)) { | |
3acb50c1 MRL |
178 | if (skb_linearize(chunk->skb)) { |
179 | __SCTP_INC_STATS(dev_net(chunk->skb->dev), SCTP_MIB_IN_PKT_DISCARDS); | |
180 | sctp_chunk_free(chunk); | |
181 | goto next_chunk; | |
182 | } | |
183 | ||
184 | /* Update sctp_hdr as it probably changed */ | |
185 | chunk->sctp_hdr = sctp_hdr(chunk->skb); | |
186 | } | |
187 | ||
90017acc MRL |
188 | if ((skb_shinfo(chunk->skb)->gso_type & SKB_GSO_SCTP) == SKB_GSO_SCTP) { |
189 | /* GSO-marked skbs but without frags, handle | |
190 | * them normally | |
191 | */ | |
192 | if (skb_shinfo(chunk->skb)->frag_list) | |
193 | chunk->head_skb = chunk->skb; | |
194 | ||
195 | /* skbs with "cover letter" */ | |
196 | if (chunk->head_skb && chunk->skb->data_len == chunk->skb->len) | |
197 | chunk->skb = skb_shinfo(chunk->skb)->frag_list; | |
198 | ||
199 | if (WARN_ON(!chunk->skb)) { | |
200 | __SCTP_INC_STATS(dev_net(chunk->skb->dev), SCTP_MIB_IN_PKT_DISCARDS); | |
201 | sctp_chunk_free(chunk); | |
202 | goto next_chunk; | |
203 | } | |
204 | } | |
205 | ||
206 | if (chunk->asoc) | |
207 | sock_rps_save_rxhash(chunk->asoc->base.sk, chunk->skb); | |
208 | ||
3acb50c1 MRL |
209 | queue->in_progress = chunk; |
210 | ||
90017acc | 211 | new_skb: |
1da177e4 | 212 | /* This is the first chunk in the packet. */ |
1da177e4 | 213 | ch = (sctp_chunkhdr_t *) chunk->skb->data; |
90017acc | 214 | chunk->singleton = 1; |
7c3ceb4f | 215 | chunk->data_accepted = 0; |
90017acc MRL |
216 | chunk->pdiscard = 0; |
217 | chunk->auth = 0; | |
218 | chunk->has_asconf = 0; | |
219 | chunk->end_of_packet = 0; | |
220 | chunk->ecn_ce_done = 0; | |
1da177e4 LT |
221 | } |
222 | ||
d808ad9a YH |
223 | chunk->chunk_hdr = ch; |
224 | chunk->chunk_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length)); | |
1da177e4 LT |
225 | skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t)); |
226 | chunk->subh.v = NULL; /* Subheader is no longer valid. */ | |
227 | ||
26b87c78 DB |
228 | if (chunk->chunk_end + sizeof(sctp_chunkhdr_t) < |
229 | skb_tail_pointer(chunk->skb)) { | |
1da177e4 LT |
230 | /* This is not a singleton */ |
231 | chunk->singleton = 0; | |
27a884dc | 232 | } else if (chunk->chunk_end > skb_tail_pointer(chunk->skb)) { |
26b87c78 DB |
233 | /* Discard inside state machine. */ |
234 | chunk->pdiscard = 1; | |
235 | chunk->chunk_end = skb_tail_pointer(chunk->skb); | |
1da177e4 LT |
236 | } else { |
237 | /* We are at the end of the packet, so mark the chunk | |
238 | * in case we need to send a SACK. | |
239 | */ | |
240 | chunk->end_of_packet = 1; | |
241 | } | |
242 | ||
bb33381d DB |
243 | pr_debug("+++sctp_inq_pop+++ chunk:%p[%s], length:%d, skb->len:%d\n", |
244 | chunk, sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)), | |
245 | ntohs(chunk->chunk_hdr->length), chunk->skb->len); | |
246 | ||
1da177e4 LT |
247 | return chunk; |
248 | } | |
249 | ||
250 | /* Set a top-half handler. | |
251 | * | |
252 | * Originally, we the top-half handler was scheduled as a BH. We now | |
253 | * call the handler directly in sctp_inq_push() at a time that | |
254 | * we know we are lock safe. | |
255 | * The intent is that this routine will pull stuff out of the | |
256 | * inqueue and process it. | |
257 | */ | |
c4028958 | 258 | void sctp_inq_set_th_handler(struct sctp_inq *q, work_func_t callback) |
1da177e4 | 259 | { |
c4028958 | 260 | INIT_WORK(&q->immediate, callback); |
1da177e4 | 261 | } |