1 | /* |
2 | * Copyright (c) 2003-2008 Fabrice Bellard |
3 | * Copyright (c) 2009 Red Hat, Inc. |
4 | * |
5 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
6 | * of this software and associated documentation files (the "Software"), to deal |
7 | * in the Software without restriction, including without limitation the rights |
8 | * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
9 | * copies of the Software, and to permit persons to whom the Software is |
10 | * furnished to do so, subject to the following conditions: |
11 | * |
12 | * The above copyright notice and this permission notice shall be included in |
13 | * all copies or substantial portions of the Software. |
14 | * |
15 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
16 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
17 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
18 | * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
19 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
20 | * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
21 | * THE SOFTWARE. |
22 | */ |
23 | |
24 | #include "qemu/osdep.h" |
25 | #include "net/queue.h" |
26 | #include "qemu/queue.h" |
27 | #include "net/net.h" |
28 | |
29 | /* The delivery handler may only return zero if it will call |
30 | * qemu_net_queue_flush() when it determines that it is once again able |
31 | * to deliver packets. It must also call qemu_net_queue_purge() in its |
32 | * cleanup path. |
33 | * |
34 | * If a sent callback is provided to send(), the caller must handle a |
35 | * zero return from the delivery handler by not sending any more packets |
36 | * until we have invoked the callback. Only in that case will we queue |
37 | * the packet. |
38 | * |
39 | * If a sent callback isn't provided, we just drop the packet to avoid |
40 | * unbounded queueing. |
41 | */ |
42 | |
43 | struct NetPacket { |
44 | QTAILQ_ENTRY(NetPacket) entry; |
45 | NetClientState *sender; |
46 | unsigned flags; |
47 | int size; |
48 | NetPacketSent *sent_cb; |
49 | uint8_t data[0]; |
50 | }; |
51 | |
52 | struct NetQueue { |
53 | void *opaque; |
54 | uint32_t nq_maxlen; |
55 | uint32_t nq_count; |
56 | NetQueueDeliverFunc *deliver; |
57 | |
58 | QTAILQ_HEAD(, NetPacket) packets; |
59 | |
60 | unsigned delivering : 1; |
61 | }; |
62 | |
63 | NetQueue *qemu_new_net_queue(NetQueueDeliverFunc *deliver, void *opaque) |
64 | { |
65 | NetQueue *queue; |
66 | |
67 | queue = g_new0(NetQueue, 1); |
68 | |
69 | queue->opaque = opaque; |
70 | queue->nq_maxlen = 10000; |
71 | queue->nq_count = 0; |
72 | queue->deliver = deliver; |
73 | |
74 | QTAILQ_INIT(&queue->packets); |
75 | |
76 | queue->delivering = 0; |
77 | |
78 | return queue; |
79 | } |
80 | |
81 | void qemu_del_net_queue(NetQueue *queue) |
82 | { |
83 | NetPacket *packet, *next; |
84 | |
85 | QTAILQ_FOREACH_SAFE(packet, &queue->packets, entry, next) { |
86 | QTAILQ_REMOVE(&queue->packets, packet, entry); |
87 | g_free(packet); |
88 | } |
89 | |
90 | g_free(queue); |
91 | } |
92 | |
93 | static void qemu_net_queue_append(NetQueue *queue, |
94 | NetClientState *sender, |
95 | unsigned flags, |
96 | const uint8_t *buf, |
97 | size_t size, |
98 | NetPacketSent *sent_cb) |
99 | { |
100 | NetPacket *packet; |
101 | |
102 | if (queue->nq_count >= queue->nq_maxlen && !sent_cb) { |
103 | return; /* drop if queue full and no callback */ |
104 | } |
105 | packet = g_malloc(sizeof(NetPacket) + size); |
106 | packet->sender = sender; |
107 | packet->flags = flags; |
108 | packet->size = size; |
109 | packet->sent_cb = sent_cb; |
110 | memcpy(packet->data, buf, size); |
111 | |
112 | queue->nq_count++; |
113 | QTAILQ_INSERT_TAIL(&queue->packets, packet, entry); |
114 | } |
115 | |
116 | void qemu_net_queue_append_iov(NetQueue *queue, |
117 | NetClientState *sender, |
118 | unsigned flags, |
119 | const struct iovec *iov, |
120 | int iovcnt, |
121 | NetPacketSent *sent_cb) |
122 | { |
123 | NetPacket *packet; |
124 | size_t max_len = 0; |
125 | int i; |
126 | |
127 | if (queue->nq_count >= queue->nq_maxlen && !sent_cb) { |
128 | return; /* drop if queue full and no callback */ |
129 | } |
130 | for (i = 0; i < iovcnt; i++) { |
131 | max_len += iov[i].iov_len; |
132 | } |
133 | |
134 | packet = g_malloc(sizeof(NetPacket) + max_len); |
135 | packet->sender = sender; |
136 | packet->sent_cb = sent_cb; |
137 | packet->flags = flags; |
138 | packet->size = 0; |
139 | |
140 | for (i = 0; i < iovcnt; i++) { |
141 | size_t len = iov[i].iov_len; |
142 | |
143 | memcpy(packet->data + packet->size, iov[i].iov_base, len); |
144 | packet->size += len; |
145 | } |
146 | |
147 | queue->nq_count++; |
148 | QTAILQ_INSERT_TAIL(&queue->packets, packet, entry); |
149 | } |
150 | |
151 | static ssize_t qemu_net_queue_deliver(NetQueue *queue, |
152 | NetClientState *sender, |
153 | unsigned flags, |
154 | const uint8_t *data, |
155 | size_t size) |
156 | { |
157 | ssize_t ret = -1; |
158 | struct iovec iov = { |
159 | .iov_base = (void *)data, |
160 | .iov_len = size |
161 | }; |
162 | |
163 | queue->delivering = 1; |
164 | ret = queue->deliver(sender, flags, &iov, 1, queue->opaque); |
165 | queue->delivering = 0; |
166 | |
167 | return ret; |
168 | } |
169 | |
170 | static ssize_t qemu_net_queue_deliver_iov(NetQueue *queue, |
171 | NetClientState *sender, |
172 | unsigned flags, |
173 | const struct iovec *iov, |
174 | int iovcnt) |
175 | { |
176 | ssize_t ret = -1; |
177 | |
178 | queue->delivering = 1; |
179 | ret = queue->deliver(sender, flags, iov, iovcnt, queue->opaque); |
180 | queue->delivering = 0; |
181 | |
182 | return ret; |
183 | } |
184 | |
185 | ssize_t qemu_net_queue_send(NetQueue *queue, |
186 | NetClientState *sender, |
187 | unsigned flags, |
188 | const uint8_t *data, |
189 | size_t size, |
190 | NetPacketSent *sent_cb) |
191 | { |
192 | ssize_t ret; |
193 | |
194 | if (queue->delivering || !qemu_can_send_packet(sender)) { |
195 | qemu_net_queue_append(queue, sender, flags, data, size, sent_cb); |
196 | return 0; |
197 | } |
198 | |
199 | ret = qemu_net_queue_deliver(queue, sender, flags, data, size); |
200 | if (ret == 0) { |
201 | qemu_net_queue_append(queue, sender, flags, data, size, sent_cb); |
202 | return 0; |
203 | } |
204 | |
205 | qemu_net_queue_flush(queue); |
206 | |
207 | return ret; |
208 | } |
209 | |
210 | ssize_t qemu_net_queue_send_iov(NetQueue *queue, |
211 | NetClientState *sender, |
212 | unsigned flags, |
213 | const struct iovec *iov, |
214 | int iovcnt, |
215 | NetPacketSent *sent_cb) |
216 | { |
217 | ssize_t ret; |
218 | |
219 | if (queue->delivering || !qemu_can_send_packet(sender)) { |
220 | qemu_net_queue_append_iov(queue, sender, flags, iov, iovcnt, sent_cb); |
221 | return 0; |
222 | } |
223 | |
224 | ret = qemu_net_queue_deliver_iov(queue, sender, flags, iov, iovcnt); |
225 | if (ret == 0) { |
226 | qemu_net_queue_append_iov(queue, sender, flags, iov, iovcnt, sent_cb); |
227 | return 0; |
228 | } |
229 | |
230 | qemu_net_queue_flush(queue); |
231 | |
232 | return ret; |
233 | } |
234 | |
235 | void qemu_net_queue_purge(NetQueue *queue, NetClientState *from) |
236 | { |
237 | NetPacket *packet, *next; |
238 | |
239 | QTAILQ_FOREACH_SAFE(packet, &queue->packets, entry, next) { |
240 | if (packet->sender == from) { |
241 | QTAILQ_REMOVE(&queue->packets, packet, entry); |
242 | queue->nq_count--; |
243 | if (packet->sent_cb) { |
244 | packet->sent_cb(packet->sender, 0); |
245 | } |
246 | g_free(packet); |
247 | } |
248 | } |
249 | } |
250 | |
251 | bool qemu_net_queue_flush(NetQueue *queue) |
252 | { |
253 | while (!QTAILQ_EMPTY(&queue->packets)) { |
254 | NetPacket *packet; |
255 | int ret; |
256 | |
257 | packet = QTAILQ_FIRST(&queue->packets); |
258 | QTAILQ_REMOVE(&queue->packets, packet, entry); |
259 | queue->nq_count--; |
260 | |
261 | ret = qemu_net_queue_deliver(queue, |
262 | packet->sender, |
263 | packet->flags, |
264 | packet->data, |
265 | packet->size); |
266 | if (ret == 0) { |
267 | queue->nq_count++; |
268 | QTAILQ_INSERT_HEAD(&queue->packets, packet, entry); |
269 | return false; |
270 | } |
271 | |
272 | if (packet->sent_cb) { |
273 | packet->sent_cb(packet->sender, ret); |
274 | } |
275 | |
276 | g_free(packet); |
277 | } |
278 | return true; |
279 | } |
280 | |