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1/* SCTP kernel 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 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 * This SCTP 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 * This SCTP 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, see
28 * <http://www.gnu.org/licenses/>.
29 *
30 * Please send any bug reports or fixes you make to the
31 * email address(es):
32 * lksctp developers <linux-sctp@vger.kernel.org>
33 *
34 * Written or modified by:
35 * La Monte H.P. Yarroll <piggy@acm.org>
36 * Karl Knutson <karl@athena.chicago.il.us>
37 */
38
39#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
40
41#include <net/sctp/sctp.h>
42#include <net/sctp/sm.h>
43#include <linux/interrupt.h>
44#include <linux/slab.h>
45
46/* Initialize an SCTP inqueue. */
47void sctp_inq_init(struct sctp_inq *queue)
48{
49 INIT_LIST_HEAD(&queue->in_chunk_list);
50 queue->in_progress = NULL;
51
52 /* Create a task for delivering data. */
53 INIT_WORK(&queue->immediate, NULL);
54}
55
56/* Release the memory associated with an SCTP inqueue. */
57void sctp_inq_free(struct sctp_inq *queue)
58{
59 struct sctp_chunk *chunk, *tmp;
60
61 /* Empty the queue. */
62 list_for_each_entry_safe(chunk, tmp, &queue->in_chunk_list, list) {
63 list_del_init(&chunk->list);
64 sctp_chunk_free(chunk);
65 }
66
67 /* If there is a packet which is currently being worked on,
68 * free it as well.
69 */
70 if (queue->in_progress) {
71 sctp_chunk_free(queue->in_progress);
72 queue->in_progress = NULL;
73 }
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 */
79void sctp_inq_push(struct sctp_inq *q, struct sctp_chunk *chunk)
80{
81 /* Directly call the packet handling routine. */
82 if (chunk->rcvr->dead) {
83 sctp_chunk_free(chunk);
84 return;
85 }
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 */
92 list_add_tail(&chunk->list, &q->in_chunk_list);
93 if (chunk->asoc)
94 chunk->asoc->stats.ipackets++;
95 q->immediate.func(&q->immediate);
96}
97
98/* 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
117/* 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;
143
144 /* Force chunk->skb->data to chunk->chunk_end. */
145 skb_pull(chunk->skb,
146 chunk->chunk_end - chunk->skb->data);
147
148 /* Verify that we have at least chunk headers
149 * worth of buffer left.
150 */
151 if (skb_headlen(chunk->skb) < sizeof(sctp_chunkhdr_t)) {
152 sctp_chunk_free(chunk);
153 chunk = queue->in_progress = NULL;
154 }
155 }
156 }
157
158 /* Do we need to take the next packet out of the queue to process? */
159 if (!chunk) {
160 struct list_head *entry;
161
162 /* Is the queue empty? */
163 if (list_empty(&queue->in_chunk_list))
164 return NULL;
165
166 entry = queue->in_chunk_list.next;
167 chunk = queue->in_progress =
168 list_entry(entry, struct sctp_chunk, list);
169 list_del_init(entry);
170
171 /* This is the first chunk in the packet. */
172 chunk->singleton = 1;
173 ch = (sctp_chunkhdr_t *) chunk->skb->data;
174 chunk->data_accepted = 0;
175 }
176
177 chunk->chunk_hdr = ch;
178 chunk->chunk_end = ((__u8 *)ch) + WORD_ROUND(ntohs(ch->length));
179 /* In the unlikely case of an IP reassembly, the skb could be
180 * non-linear. If so, update chunk_end so that it doesn't go past
181 * the skb->tail.
182 */
183 if (unlikely(skb_is_nonlinear(chunk->skb))) {
184 if (chunk->chunk_end > skb_tail_pointer(chunk->skb))
185 chunk->chunk_end = skb_tail_pointer(chunk->skb);
186 }
187 skb_pull(chunk->skb, sizeof(sctp_chunkhdr_t));
188 chunk->subh.v = NULL; /* Subheader is no longer valid. */
189
190 if (chunk->chunk_end < skb_tail_pointer(chunk->skb)) {
191 /* This is not a singleton */
192 chunk->singleton = 0;
193 } else if (chunk->chunk_end > skb_tail_pointer(chunk->skb)) {
194 /* RFC 2960, Section 6.10 Bundling
195 *
196 * Partial chunks MUST NOT be placed in an SCTP packet.
197 * If the receiver detects a partial chunk, it MUST drop
198 * the chunk.
199 *
200 * Since the end of the chunk is past the end of our buffer
201 * (which contains the whole packet, we can freely discard
202 * the whole packet.
203 */
204 sctp_chunk_free(chunk);
205 chunk = queue->in_progress = NULL;
206
207 return NULL;
208 } else {
209 /* We are at the end of the packet, so mark the chunk
210 * in case we need to send a SACK.
211 */
212 chunk->end_of_packet = 1;
213 }
214
215 pr_debug("+++sctp_inq_pop+++ chunk:%p[%s], length:%d, skb->len:%d\n",
216 chunk, sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)),
217 ntohs(chunk->chunk_hdr->length), chunk->skb->len);
218
219 return chunk;
220}
221
222/* Set a top-half handler.
223 *
224 * Originally, we the top-half handler was scheduled as a BH. We now
225 * call the handler directly in sctp_inq_push() at a time that
226 * we know we are lock safe.
227 * The intent is that this routine will pull stuff out of the
228 * inqueue and process it.
229 */
230void sctp_inq_set_th_handler(struct sctp_inq *q, work_func_t callback)
231{
232 INIT_WORK(&q->immediate, callback);
233}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* SCTP kernel implementation
3 * Copyright (c) 1999-2000 Cisco, Inc.
4 * Copyright (c) 1999-2001 Motorola, Inc.
5 * Copyright (c) 2002 International Business Machines, Corp.
6 *
7 * This file is part of the SCTP kernel implementation
8 *
9 * These functions are the methods for accessing the SCTP inqueue.
10 *
11 * An SCTP inqueue is a queue into which you push SCTP packets
12 * (which might be bundles or fragments of chunks) and out of which you
13 * pop SCTP whole chunks.
14 *
15 * Please send any bug reports or fixes you make to the
16 * email address(es):
17 * lksctp developers <linux-sctp@vger.kernel.org>
18 *
19 * Written or modified by:
20 * La Monte H.P. Yarroll <piggy@acm.org>
21 * Karl Knutson <karl@athena.chicago.il.us>
22 */
23
24#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
25
26#include <net/sctp/sctp.h>
27#include <net/sctp/sm.h>
28#include <linux/interrupt.h>
29#include <linux/slab.h>
30
31/* Initialize an SCTP inqueue. */
32void sctp_inq_init(struct sctp_inq *queue)
33{
34 INIT_LIST_HEAD(&queue->in_chunk_list);
35 queue->in_progress = NULL;
36
37 /* Create a task for delivering data. */
38 INIT_WORK(&queue->immediate, NULL);
39}
40
41/* Properly release the chunk which is being worked on. */
42static inline void sctp_inq_chunk_free(struct sctp_chunk *chunk)
43{
44 if (chunk->head_skb)
45 chunk->skb = chunk->head_skb;
46 sctp_chunk_free(chunk);
47}
48
49/* Release the memory associated with an SCTP inqueue. */
50void sctp_inq_free(struct sctp_inq *queue)
51{
52 struct sctp_chunk *chunk, *tmp;
53
54 /* Empty the queue. */
55 list_for_each_entry_safe(chunk, tmp, &queue->in_chunk_list, list) {
56 list_del_init(&chunk->list);
57 sctp_chunk_free(chunk);
58 }
59
60 /* If there is a packet which is currently being worked on,
61 * free it as well.
62 */
63 if (queue->in_progress) {
64 sctp_inq_chunk_free(queue->in_progress);
65 queue->in_progress = NULL;
66 }
67}
68
69/* Put a new packet in an SCTP inqueue.
70 * We assume that packet->sctp_hdr is set and in host byte order.
71 */
72void sctp_inq_push(struct sctp_inq *q, struct sctp_chunk *chunk)
73{
74 /* Directly call the packet handling routine. */
75 if (chunk->rcvr->dead) {
76 sctp_chunk_free(chunk);
77 return;
78 }
79
80 /* We are now calling this either from the soft interrupt
81 * or from the backlog processing.
82 * Eventually, we should clean up inqueue to not rely
83 * on the BH related data structures.
84 */
85 list_add_tail(&chunk->list, &q->in_chunk_list);
86 if (chunk->asoc)
87 chunk->asoc->stats.ipackets++;
88 q->immediate.func(&q->immediate);
89}
90
91/* Peek at the next chunk on the inqeue. */
92struct sctp_chunkhdr *sctp_inq_peek(struct sctp_inq *queue)
93{
94 struct sctp_chunk *chunk;
95 struct sctp_chunkhdr *ch = NULL;
96
97 chunk = queue->in_progress;
98 /* If there is no more chunks in this packet, say so */
99 if (chunk->singleton ||
100 chunk->end_of_packet ||
101 chunk->pdiscard)
102 return NULL;
103
104 ch = (struct sctp_chunkhdr *)chunk->chunk_end;
105
106 return ch;
107}
108
109
110/* Extract a chunk from an SCTP inqueue.
111 *
112 * WARNING: If you need to put the chunk on another queue, you need to
113 * make a shallow copy (clone) of it.
114 */
115struct sctp_chunk *sctp_inq_pop(struct sctp_inq *queue)
116{
117 struct sctp_chunk *chunk;
118 struct sctp_chunkhdr *ch = NULL;
119
120 /* The assumption is that we are safe to process the chunks
121 * at this time.
122 */
123
124 chunk = queue->in_progress;
125 if (chunk) {
126 /* There is a packet that we have been working on.
127 * Any post processing work to do before we move on?
128 */
129 if (chunk->singleton ||
130 chunk->end_of_packet ||
131 chunk->pdiscard) {
132 if (chunk->head_skb == chunk->skb) {
133 chunk->skb = skb_shinfo(chunk->skb)->frag_list;
134 goto new_skb;
135 }
136 if (chunk->skb->next) {
137 chunk->skb = chunk->skb->next;
138 goto new_skb;
139 }
140
141 sctp_inq_chunk_free(chunk);
142 chunk = queue->in_progress = NULL;
143 } else {
144 /* Nothing to do. Next chunk in the packet, please. */
145 ch = (struct sctp_chunkhdr *)chunk->chunk_end;
146 /* Force chunk->skb->data to chunk->chunk_end. */
147 skb_pull(chunk->skb, chunk->chunk_end - chunk->skb->data);
148 /* We are guaranteed to pull a SCTP header. */
149 }
150 }
151
152 /* Do we need to take the next packet out of the queue to process? */
153 if (!chunk) {
154 struct list_head *entry;
155
156next_chunk:
157 /* Is the queue empty? */
158 entry = sctp_list_dequeue(&queue->in_chunk_list);
159 if (!entry)
160 return NULL;
161
162 chunk = list_entry(entry, struct sctp_chunk, list);
163
164 if (skb_is_gso(chunk->skb) && skb_is_gso_sctp(chunk->skb)) {
165 /* GSO-marked skbs but without frags, handle
166 * them normally
167 */
168 if (skb_shinfo(chunk->skb)->frag_list)
169 chunk->head_skb = chunk->skb;
170
171 /* skbs with "cover letter" */
172 if (chunk->head_skb && chunk->skb->data_len == chunk->skb->len)
173 chunk->skb = skb_shinfo(chunk->skb)->frag_list;
174
175 if (WARN_ON(!chunk->skb)) {
176 __SCTP_INC_STATS(dev_net(chunk->skb->dev), SCTP_MIB_IN_PKT_DISCARDS);
177 sctp_chunk_free(chunk);
178 goto next_chunk;
179 }
180 }
181
182 if (chunk->asoc)
183 sock_rps_save_rxhash(chunk->asoc->base.sk, chunk->skb);
184
185 queue->in_progress = chunk;
186
187new_skb:
188 /* This is the first chunk in the packet. */
189 ch = (struct sctp_chunkhdr *)chunk->skb->data;
190 chunk->singleton = 1;
191 chunk->data_accepted = 0;
192 chunk->pdiscard = 0;
193 chunk->auth = 0;
194 chunk->has_asconf = 0;
195 chunk->end_of_packet = 0;
196 if (chunk->head_skb) {
197 struct sctp_input_cb
198 *cb = SCTP_INPUT_CB(chunk->skb),
199 *head_cb = SCTP_INPUT_CB(chunk->head_skb);
200
201 cb->chunk = head_cb->chunk;
202 cb->af = head_cb->af;
203 }
204 }
205
206 chunk->chunk_hdr = ch;
207 chunk->chunk_end = ((__u8 *)ch) + SCTP_PAD4(ntohs(ch->length));
208 skb_pull(chunk->skb, sizeof(*ch));
209 chunk->subh.v = NULL; /* Subheader is no longer valid. */
210
211 if (chunk->chunk_end + sizeof(*ch) <= skb_tail_pointer(chunk->skb)) {
212 /* This is not a singleton */
213 chunk->singleton = 0;
214 } else if (chunk->chunk_end > skb_tail_pointer(chunk->skb)) {
215 /* Discard inside state machine. */
216 chunk->pdiscard = 1;
217 chunk->chunk_end = skb_tail_pointer(chunk->skb);
218 } else {
219 /* We are at the end of the packet, so mark the chunk
220 * in case we need to send a SACK.
221 */
222 chunk->end_of_packet = 1;
223 }
224
225 pr_debug("+++sctp_inq_pop+++ chunk:%p[%s], length:%d, skb->len:%d\n",
226 chunk, sctp_cname(SCTP_ST_CHUNK(chunk->chunk_hdr->type)),
227 ntohs(chunk->chunk_hdr->length), chunk->skb->len);
228
229 return chunk;
230}
231
232/* Set a top-half handler.
233 *
234 * Originally, we the top-half handler was scheduled as a BH. We now
235 * call the handler directly in sctp_inq_push() at a time that
236 * we know we are lock safe.
237 * The intent is that this routine will pull stuff out of the
238 * inqueue and process it.
239 */
240void sctp_inq_set_th_handler(struct sctp_inq *q, work_func_t callback)
241{
242 INIT_WORK(&q->immediate, callback);
243}