1 /*
2 * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 * 3. The name of the author may not be used to endorse or promote products
13 * derived from this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 /**
28 @file buffer_iocp.c
29
30 This module implements overlapped read and write functions for evbuffer
31 objects on Windows.
32 */
33 #include "event2/event-config.h"
34 #include "evconfig-private.h"
35
36 #include "event2/buffer.h"
37 #include "event2/buffer_compat.h"
38 #include "event2/util.h"
39 #include "event2/thread.h"
40 #include "util-internal.h"
41 #include "evthread-internal.h"
42 #include "evbuffer-internal.h"
43 #include "iocp-internal.h"
44 #include "mm-internal.h"
45
46 #include <winsock2.h>
47 #include <winerror.h>
48 #include <windows.h>
49 #include <stdio.h>
50
51 #define MAX_WSABUFS 16
52
53 /** An evbuffer that can handle overlapped IO. */
54 struct evbuffer_overlapped {
55 struct evbuffer buffer;
56 /** The socket that we're doing overlapped IO on. */
57 evutil_socket_t fd;
58
59 /** pending I/O type */
60 unsigned read_in_progress : 1;
61 unsigned write_in_progress : 1;
62
63 /** The first pinned chain in the buffer. */
64 struct evbuffer_chain *first_pinned;
65
66 /** How many chains are pinned; how many of the fields in buffers
67 * are we using. */
68 int n_buffers;
69 WSABUF buffers[MAX_WSABUFS];
70 };
71
72 /** Given an evbuffer, return the correponding evbuffer structure, or NULL if
73 * the evbuffer isn't overlapped. */
74 static inline struct evbuffer_overlapped *
upcast_evbuffer(struct evbuffer * buf)75 upcast_evbuffer(struct evbuffer *buf)
76 {
77 if (!buf || !buf->is_overlapped)
78 return NULL;
79 return EVUTIL_UPCAST(buf, struct evbuffer_overlapped, buffer);
80 }
81
82 /** Unpin all the chains noted as pinned in 'eo'. */
83 static void
pin_release(struct evbuffer_overlapped * eo,unsigned flag)84 pin_release(struct evbuffer_overlapped *eo, unsigned flag)
85 {
86 int i;
87 struct evbuffer_chain *next, *chain = eo->first_pinned;
88
89 for (i = 0; i < eo->n_buffers; ++i) {
90 EVUTIL_ASSERT(chain);
91 next = chain->next;
92 evbuffer_chain_unpin_(chain, flag);
93 chain = next;
94 }
95 }
96
97 void
evbuffer_commit_read_(struct evbuffer * evbuf,ev_ssize_t nBytes)98 evbuffer_commit_read_(struct evbuffer *evbuf, ev_ssize_t nBytes)
99 {
100 struct evbuffer_overlapped *buf = upcast_evbuffer(evbuf);
101 struct evbuffer_chain **chainp;
102 size_t remaining, len;
103 unsigned i;
104
105 EVBUFFER_LOCK(evbuf);
106 EVUTIL_ASSERT(buf->read_in_progress && !buf->write_in_progress);
107 EVUTIL_ASSERT(nBytes >= 0); /* XXXX Can this be false? */
108
109 evbuffer_unfreeze(evbuf, 0);
110
111 chainp = evbuf->last_with_datap;
112 if (!((*chainp)->flags & EVBUFFER_MEM_PINNED_R))
113 chainp = &(*chainp)->next;
114 remaining = nBytes;
115 for (i = 0; remaining > 0 && i < (unsigned)buf->n_buffers; ++i) {
116 EVUTIL_ASSERT(*chainp);
117 len = buf->buffers[i].len;
118 if (remaining < len)
119 len = remaining;
120 (*chainp)->off += len;
121 evbuf->last_with_datap = chainp;
122 remaining -= len;
123 chainp = &(*chainp)->next;
124 }
125
126 pin_release(buf, EVBUFFER_MEM_PINNED_R);
127
128 buf->read_in_progress = 0;
129
130 evbuf->total_len += nBytes;
131 evbuf->n_add_for_cb += nBytes;
132
133 evbuffer_invoke_callbacks_(evbuf);
134
135 evbuffer_decref_and_unlock_(evbuf);
136 }
137
138 void
evbuffer_commit_write_(struct evbuffer * evbuf,ev_ssize_t nBytes)139 evbuffer_commit_write_(struct evbuffer *evbuf, ev_ssize_t nBytes)
140 {
141 struct evbuffer_overlapped *buf = upcast_evbuffer(evbuf);
142
143 EVBUFFER_LOCK(evbuf);
144 EVUTIL_ASSERT(buf->write_in_progress && !buf->read_in_progress);
145 evbuffer_unfreeze(evbuf, 1);
146 evbuffer_drain(evbuf, nBytes);
147 pin_release(buf,EVBUFFER_MEM_PINNED_W);
148 buf->write_in_progress = 0;
149 evbuffer_decref_and_unlock_(evbuf);
150 }
151
152 struct evbuffer *
evbuffer_overlapped_new_(evutil_socket_t fd)153 evbuffer_overlapped_new_(evutil_socket_t fd)
154 {
155 struct evbuffer_overlapped *evo;
156
157 evo = mm_calloc(1, sizeof(struct evbuffer_overlapped));
158 if (!evo)
159 return NULL;
160
161 LIST_INIT(&evo->buffer.callbacks);
162 evo->buffer.refcnt = 1;
163 evo->buffer.last_with_datap = &evo->buffer.first;
164
165 evo->buffer.is_overlapped = 1;
166 evo->fd = fd;
167
168 return &evo->buffer;
169 }
170
171 int
evbuffer_launch_write_(struct evbuffer * buf,ev_ssize_t at_most,struct event_overlapped * ol)172 evbuffer_launch_write_(struct evbuffer *buf, ev_ssize_t at_most,
173 struct event_overlapped *ol)
174 {
175 struct evbuffer_overlapped *buf_o = upcast_evbuffer(buf);
176 int r = -1;
177 int i;
178 struct evbuffer_chain *chain;
179 DWORD bytesSent;
180
181 if (!buf) {
182 /* No buffer, or it isn't overlapped */
183 return -1;
184 }
185
186 EVBUFFER_LOCK(buf);
187 EVUTIL_ASSERT(!buf_o->read_in_progress);
188 if (buf->freeze_start || buf_o->write_in_progress)
189 goto done;
190 if (!buf->total_len) {
191 /* Nothing to write */
192 r = 0;
193 goto done;
194 } else if (at_most < 0 || (size_t)at_most > buf->total_len) {
195 at_most = buf->total_len;
196 }
197 evbuffer_freeze(buf, 1);
198
199 buf_o->first_pinned = NULL;
200 buf_o->n_buffers = 0;
201 memset(buf_o->buffers, 0, sizeof(buf_o->buffers));
202
203 chain = buf_o->first_pinned = buf->first;
204
205 for (i=0; i < MAX_WSABUFS && chain; ++i, chain=chain->next) {
206 WSABUF *b = &buf_o->buffers[i];
207 b->buf = (char*)( chain->buffer + chain->misalign );
208 evbuffer_chain_pin_(chain, EVBUFFER_MEM_PINNED_W);
209
210 if ((size_t)at_most > chain->off) {
211 /* XXXX Cast is safe for now, since win32 has no
212 mmaped chains. But later, we need to have this
213 add more WSAbufs if chain->off is greater than
214 ULONG_MAX */
215 b->len = (unsigned long)chain->off;
216 at_most -= chain->off;
217 } else {
218 b->len = (unsigned long)at_most;
219 ++i;
220 break;
221 }
222 }
223
224 buf_o->n_buffers = i;
225 evbuffer_incref_(buf);
226 if (WSASend(buf_o->fd, buf_o->buffers, i, &bytesSent, 0,
227 &ol->overlapped, NULL)) {
228 int error = WSAGetLastError();
229 if (error != WSA_IO_PENDING) {
230 /* An actual error. */
231 pin_release(buf_o, EVBUFFER_MEM_PINNED_W);
232 evbuffer_unfreeze(buf, 1);
233 evbuffer_free(buf); /* decref */
234 goto done;
235 }
236 }
237
238 buf_o->write_in_progress = 1;
239 r = 0;
240 done:
241 EVBUFFER_UNLOCK(buf);
242 return r;
243 }
244
245 int
evbuffer_launch_read_(struct evbuffer * buf,size_t at_most,struct event_overlapped * ol)246 evbuffer_launch_read_(struct evbuffer *buf, size_t at_most,
247 struct event_overlapped *ol)
248 {
249 struct evbuffer_overlapped *buf_o = upcast_evbuffer(buf);
250 int r = -1, i;
251 int nvecs;
252 int npin=0;
253 struct evbuffer_chain *chain=NULL, **chainp;
254 DWORD bytesRead;
255 DWORD flags = 0;
256 struct evbuffer_iovec vecs[MAX_WSABUFS];
257
258 if (!buf_o)
259 return -1;
260 EVBUFFER_LOCK(buf);
261 EVUTIL_ASSERT(!buf_o->write_in_progress);
262 if (buf->freeze_end || buf_o->read_in_progress)
263 goto done;
264
265 buf_o->first_pinned = NULL;
266 buf_o->n_buffers = 0;
267 memset(buf_o->buffers, 0, sizeof(buf_o->buffers));
268
269 if (evbuffer_expand_fast_(buf, at_most, MAX_WSABUFS) == -1)
270 goto done;
271 evbuffer_freeze(buf, 0);
272
273 nvecs = evbuffer_read_setup_vecs_(buf, at_most,
274 vecs, MAX_WSABUFS, &chainp, 1);
275 for (i=0;i<nvecs;++i) {
276 WSABUF_FROM_EVBUFFER_IOV(
277 &buf_o->buffers[i],
278 &vecs[i]);
279 }
280
281 buf_o->n_buffers = nvecs;
282 buf_o->first_pinned = chain = *chainp;
283
284 npin=0;
285 for ( ; chain; chain = chain->next) {
286 evbuffer_chain_pin_(chain, EVBUFFER_MEM_PINNED_R);
287 ++npin;
288 }
289 EVUTIL_ASSERT(npin == nvecs);
290
291 evbuffer_incref_(buf);
292 if (WSARecv(buf_o->fd, buf_o->buffers, nvecs, &bytesRead, &flags,
293 &ol->overlapped, NULL)) {
294 int error = WSAGetLastError();
295 if (error != WSA_IO_PENDING) {
296 /* An actual error. */
297 pin_release(buf_o, EVBUFFER_MEM_PINNED_R);
298 evbuffer_unfreeze(buf, 0);
299 evbuffer_free(buf); /* decref */
300 goto done;
301 }
302 }
303
304 buf_o->read_in_progress = 1;
305 r = 0;
306 done:
307 EVBUFFER_UNLOCK(buf);
308 return r;
309 }
310
311 evutil_socket_t
evbuffer_overlapped_get_fd_(struct evbuffer * buf)312 evbuffer_overlapped_get_fd_(struct evbuffer *buf)
313 {
314 struct evbuffer_overlapped *buf_o = upcast_evbuffer(buf);
315 return buf_o ? buf_o->fd : -1;
316 }
317
318 void
evbuffer_overlapped_set_fd_(struct evbuffer * buf,evutil_socket_t fd)319 evbuffer_overlapped_set_fd_(struct evbuffer *buf, evutil_socket_t fd)
320 {
321 struct evbuffer_overlapped *buf_o = upcast_evbuffer(buf);
322 EVBUFFER_LOCK(buf);
323 /* XXX is this right?, should it cancel current I/O operations? */
324 if (buf_o)
325 buf_o->fd = fd;
326 EVBUFFER_UNLOCK(buf);
327 }
328