1 /*
2 * Copyright (c) 2002, 2003 Niels Provos <provos@citi.umich.edu>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * 3. The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 #ifdef HAVE_CONFIG_H
29 #include "config.h"
30 #endif
31
32 #ifdef HAVE_VASPRINTF
33 /* If we have vasprintf, we need to define this before we include stdio.h. */
34 #define _GNU_SOURCE
35 #endif
36
37 #include <sys/types.h>
38
39 #ifdef HAVE_SYS_TIME_H
40 #include <sys/time.h>
41 #endif
42
43 #ifdef HAVE_SYS_IOCTL_H
44 #include <sys/ioctl.h>
45 #endif
46
47 #include <errno.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #ifdef HAVE_STDARG_H
52 #include <stdarg.h>
53 #endif
54 #ifdef HAVE_UNISTD_H
55 #include <unistd.h>
56 #endif
57
58 #include "event.h"
59
60 struct evbuffer *
evbuffer_new(void)61 evbuffer_new(void)
62 {
63 struct evbuffer *buffer;
64
65 buffer = calloc(1, sizeof(struct evbuffer));
66
67 return (buffer);
68 }
69
70 void
evbuffer_free(struct evbuffer * buffer)71 evbuffer_free(struct evbuffer *buffer)
72 {
73 if (buffer->orig_buffer != NULL)
74 free(buffer->orig_buffer);
75 free(buffer);
76 }
77
78 /*
79 * This is a destructive add. The data from one buffer moves into
80 * the other buffer.
81 */
82
83 #define SWAP(x,y) do { \
84 (x)->buffer = (y)->buffer; \
85 (x)->orig_buffer = (y)->orig_buffer; \
86 (x)->misalign = (y)->misalign; \
87 (x)->totallen = (y)->totallen; \
88 (x)->off = (y)->off; \
89 } while (0)
90
91 int
evbuffer_add_buffer(struct evbuffer * outbuf,struct evbuffer * inbuf)92 evbuffer_add_buffer(struct evbuffer *outbuf, struct evbuffer *inbuf)
93 {
94 int res;
95
96 /* Short cut for better performance */
97 if (outbuf->off == 0) {
98 struct evbuffer tmp;
99 size_t oldoff = inbuf->off;
100
101 /* Swap them directly */
102 SWAP(&tmp, outbuf);
103 SWAP(outbuf, inbuf);
104 SWAP(inbuf, &tmp);
105
106 /*
107 * Optimization comes with a price; we need to notify the
108 * buffer if necessary of the changes. oldoff is the amount
109 * of data that we tranfered from inbuf to outbuf
110 */
111 if (inbuf->off != oldoff && inbuf->cb != NULL)
112 (*inbuf->cb)(inbuf, oldoff, inbuf->off, inbuf->cbarg);
113 if (oldoff && outbuf->cb != NULL)
114 (*outbuf->cb)(outbuf, 0, oldoff, outbuf->cbarg);
115
116 return (0);
117 }
118
119 res = evbuffer_add(outbuf, inbuf->buffer, inbuf->off);
120 if (res == 0) {
121 /* We drain the input buffer on success */
122 evbuffer_drain(inbuf, inbuf->off);
123 }
124
125 return (res);
126 }
127
128 int
evbuffer_add_vprintf(struct evbuffer * buf,const char * fmt,va_list ap)129 evbuffer_add_vprintf(struct evbuffer *buf, const char *fmt, va_list ap)
130 {
131 char *buffer;
132 size_t space;
133 size_t oldoff = buf->off;
134 int sz;
135 va_list aq;
136
137 for (;;) {
138 buffer = (char *)buf->buffer + buf->off;
139 space = buf->totallen - buf->misalign - buf->off;
140
141 #ifndef va_copy
142 #define va_copy(dst, src) memcpy(&(dst), &(src), sizeof(va_list))
143 #endif
144 va_copy(aq, ap);
145
146 #ifdef WIN32
147 sz = vsnprintf(buffer, space - 1, fmt, aq);
148 buffer[space - 1] = '\0';
149 #else
150 sz = vsnprintf(buffer, space, fmt, aq);
151 #endif
152
153 va_end(aq);
154
155 if (sz == -1)
156 return (-1);
157 if (sz < space) {
158 buf->off += sz;
159 if (buf->cb != NULL)
160 (*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
161 return (sz);
162 }
163 if (evbuffer_expand(buf, sz + 1) == -1)
164 return (-1);
165
166 }
167 /* NOTREACHED */
168 }
169
170 int
evbuffer_add_printf(struct evbuffer * buf,const char * fmt,...)171 evbuffer_add_printf(struct evbuffer *buf, const char *fmt, ...)
172 {
173 int res = -1;
174 va_list ap;
175
176 va_start(ap, fmt);
177 res = evbuffer_add_vprintf(buf, fmt, ap);
178 va_end(ap);
179
180 return (res);
181 }
182
183 /* Reads data from an event buffer and drains the bytes read */
184
185 int
evbuffer_remove(struct evbuffer * buf,void * data,size_t datlen)186 evbuffer_remove(struct evbuffer *buf, void *data, size_t datlen)
187 {
188 size_t nread = datlen;
189 if (nread >= buf->off)
190 nread = buf->off;
191
192 memcpy(data, buf->buffer, nread);
193 evbuffer_drain(buf, nread);
194
195 return (nread);
196 }
197
198 /*
199 * Reads a line terminated by either '\r\n', '\n\r' or '\r' or '\n'.
200 * The returned buffer needs to be freed by the called.
201 */
202
203 char *
evbuffer_readline(struct evbuffer * buffer)204 evbuffer_readline(struct evbuffer *buffer)
205 {
206 u_char *data = EVBUFFER_DATA(buffer);
207 size_t len = EVBUFFER_LENGTH(buffer);
208 char *line;
209 unsigned int i;
210
211 for (i = 0; i < len; i++) {
212 if (data[i] == '\r' || data[i] == '\n')
213 break;
214 }
215
216 if (i == len)
217 return (NULL);
218
219 if ((line = malloc(i + 1)) == NULL) {
220 fprintf(stderr, "%s: out of memory\n", __func__);
221 evbuffer_drain(buffer, i);
222 return (NULL);
223 }
224
225 memcpy(line, data, i);
226 line[i] = '\0';
227
228 /*
229 * Some protocols terminate a line with '\r\n', so check for
230 * that, too.
231 */
232 if ( i < len - 1 ) {
233 char fch = data[i], sch = data[i+1];
234
235 /* Drain one more character if needed */
236 if ( (sch == '\r' || sch == '\n') && sch != fch )
237 i += 1;
238 }
239
240 evbuffer_drain(buffer, i + 1);
241
242 return (line);
243 }
244
245 /* Adds data to an event buffer */
246
247 static inline void
evbuffer_align(struct evbuffer * buf)248 evbuffer_align(struct evbuffer *buf)
249 {
250 memmove(buf->orig_buffer, buf->buffer, buf->off);
251 buf->buffer = buf->orig_buffer;
252 buf->misalign = 0;
253 }
254
255 /* Expands the available space in the event buffer to at least datlen */
256
257 int
evbuffer_expand(struct evbuffer * buf,size_t datlen)258 evbuffer_expand(struct evbuffer *buf, size_t datlen)
259 {
260 size_t need = buf->misalign + buf->off + datlen;
261
262 /* If we can fit all the data, then we don't have to do anything */
263 if (buf->totallen >= need)
264 return (0);
265
266 /*
267 * If the misalignment fulfills our data needs, we just force an
268 * alignment to happen. Afterwards, we have enough space.
269 */
270 if (buf->misalign >= datlen) {
271 evbuffer_align(buf);
272 } else {
273 void *newbuf;
274 size_t length = buf->totallen;
275
276 if (length < 256)
277 length = 256;
278 while (length < need)
279 length <<= 1;
280
281 if (buf->orig_buffer != buf->buffer)
282 evbuffer_align(buf);
283 if ((newbuf = realloc(buf->buffer, length)) == NULL)
284 return (-1);
285
286 buf->orig_buffer = buf->buffer = newbuf;
287 buf->totallen = length;
288 }
289
290 return (0);
291 }
292
293 int
evbuffer_add(struct evbuffer * buf,const void * data,size_t datlen)294 evbuffer_add(struct evbuffer *buf, const void *data, size_t datlen)
295 {
296 size_t need = buf->misalign + buf->off + datlen;
297 size_t oldoff = buf->off;
298
299 if (buf->totallen < need) {
300 if (evbuffer_expand(buf, datlen) == -1)
301 return (-1);
302 }
303
304 memcpy(buf->buffer + buf->off, data, datlen);
305 buf->off += datlen;
306
307 if (datlen && buf->cb != NULL)
308 (*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
309
310 return (0);
311 }
312
313 void
evbuffer_drain(struct evbuffer * buf,size_t len)314 evbuffer_drain(struct evbuffer *buf, size_t len)
315 {
316 size_t oldoff = buf->off;
317
318 if (len >= buf->off) {
319 buf->off = 0;
320 buf->buffer = buf->orig_buffer;
321 buf->misalign = 0;
322 goto done;
323 }
324
325 buf->buffer += len;
326 buf->misalign += len;
327
328 buf->off -= len;
329
330 done:
331 /* Tell someone about changes in this buffer */
332 if (buf->off != oldoff && buf->cb != NULL)
333 (*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
334
335 }
336
337 /*
338 * Reads data from a file descriptor into a buffer.
339 */
340
341 #define EVBUFFER_MAX_READ 4096
342
343 int
evbuffer_read(struct evbuffer * buf,int fd,int howmuch)344 evbuffer_read(struct evbuffer *buf, int fd, int howmuch)
345 {
346 u_char *p;
347 size_t oldoff = buf->off;
348 int n = EVBUFFER_MAX_READ;
349 #ifdef WIN32
350 DWORD dwBytesRead;
351 #endif
352
353 #ifdef FIONREAD
354 if (ioctl(fd, FIONREAD, &n) == -1 || n == 0) {
355 n = EVBUFFER_MAX_READ;
356 } else if (n > EVBUFFER_MAX_READ && n > howmuch) {
357 /*
358 * It's possible that a lot of data is available for
359 * reading. We do not want to exhaust resources
360 * before the reader has a chance to do something
361 * about it. If the reader does not tell us how much
362 * data we should read, we artifically limit it.
363 */
364 if (n > buf->totallen << 2)
365 n = buf->totallen << 2;
366 if (n < EVBUFFER_MAX_READ)
367 n = EVBUFFER_MAX_READ;
368 }
369 #endif
370 if (howmuch < 0 || howmuch > n)
371 howmuch = n;
372
373 /* If we don't have FIONREAD, we might waste some space here */
374 if (evbuffer_expand(buf, howmuch) == -1)
375 return (-1);
376
377 /* We can append new data at this point */
378 p = buf->buffer + buf->off;
379
380 #ifndef WIN32
381 n = read(fd, p, howmuch);
382 if (n == -1)
383 return (-1);
384 if (n == 0)
385 return (0);
386 #else
387 n = ReadFile((HANDLE)fd, p, howmuch, &dwBytesRead, NULL);
388 if (n == 0)
389 return (-1);
390 if (dwBytesRead == 0)
391 return (0);
392 n = dwBytesRead;
393 #endif
394
395 buf->off += n;
396
397 /* Tell someone about changes in this buffer */
398 if (buf->off != oldoff && buf->cb != NULL)
399 (*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
400
401 return (n);
402 }
403
404 int
evbuffer_write(struct evbuffer * buffer,int fd)405 evbuffer_write(struct evbuffer *buffer, int fd)
406 {
407 int n;
408 #ifdef WIN32
409 DWORD dwBytesWritten;
410 #endif
411
412 #ifndef WIN32
413 n = write(fd, buffer->buffer, buffer->off);
414 if (n == -1)
415 return (-1);
416 if (n == 0)
417 return (0);
418 #else
419 n = WriteFile((HANDLE)fd, buffer->buffer, buffer->off, &dwBytesWritten, NULL);
420 if (n == 0)
421 return (-1);
422 if (dwBytesWritten == 0)
423 return (0);
424 n = dwBytesWritten;
425 #endif
426 evbuffer_drain(buffer, n);
427
428 return (n);
429 }
430
431 u_char *
evbuffer_find(struct evbuffer * buffer,const u_char * what,size_t len)432 evbuffer_find(struct evbuffer *buffer, const u_char *what, size_t len)
433 {
434 size_t remain = buffer->off;
435 u_char *search = buffer->buffer;
436 u_char *p;
437
438 while ((p = memchr(search, *what, remain)) != NULL) {
439 remain = buffer->off - (size_t)(search - buffer->buffer);
440 if (remain < len)
441 break;
442 if (memcmp(p, what, len) == 0)
443 return (p);
444 search = p + 1;
445 }
446
447 return (NULL);
448 }
449
evbuffer_setcb(struct evbuffer * buffer,void (* cb)(struct evbuffer *,size_t,size_t,void *),void * cbarg)450 void evbuffer_setcb(struct evbuffer *buffer,
451 void (*cb)(struct evbuffer *, size_t, size_t, void *),
452 void *cbarg)
453 {
454 buffer->cb = cb;
455 buffer->cbarg = cbarg;
456 }
457