2 * Copyright (c) 2002, 2003 Niels Provos <provos@citi.umich.edu>
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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.
33 /* If we have vasprintf, we need to define this before we include stdio.h. */
37 #include <sys/types.h>
39 #ifdef HAVE_SYS_TIME_H
43 #ifdef HAVE_SYS_IOCTL_H
44 #include <sys/ioctl.h>
64 struct evbuffer *buffer;
66 buffer = calloc(1, sizeof(struct evbuffer));
72 evbuffer_free(struct evbuffer *buffer)
74 if (buffer->orig_buffer != NULL)
75 free(buffer->orig_buffer);
80 * This is a destructive add. The data from one buffer moves into
84 #define SWAP(x,y) do { \
85 (x)->buffer = (y)->buffer; \
86 (x)->orig_buffer = (y)->orig_buffer; \
87 (x)->misalign = (y)->misalign; \
88 (x)->totallen = (y)->totallen; \
89 (x)->off = (y)->off; \
93 evbuffer_add_buffer(struct evbuffer *outbuf, struct evbuffer *inbuf)
97 /* Short cut for better performance */
98 if (outbuf->off == 0) {
100 size_t oldoff = inbuf->off;
102 /* Swap them directly */
108 * Optimization comes with a price; we need to notify the
109 * buffer if necessary of the changes. oldoff is the amount
110 * of data that we transfered from inbuf to outbuf
112 if (inbuf->off != oldoff && inbuf->cb != NULL)
113 (*inbuf->cb)(inbuf, oldoff, inbuf->off, inbuf->cbarg);
114 if (oldoff && outbuf->cb != NULL)
115 (*outbuf->cb)(outbuf, 0, oldoff, outbuf->cbarg);
120 res = evbuffer_add(outbuf, inbuf->buffer, inbuf->off);
122 /* We drain the input buffer on success */
123 evbuffer_drain(inbuf, inbuf->off);
130 evbuffer_add_vprintf(struct evbuffer *buf, const char *fmt, va_list ap)
134 size_t oldoff = buf->off;
138 /* make sure that at least some space is available */
139 evbuffer_expand(buf, 64);
141 size_t used = buf->misalign + buf->off;
142 buffer = (char *)buf->buffer + buf->off;
143 assert(buf->totallen >= used);
144 space = buf->totallen - used;
147 #define va_copy(dst, src) memcpy(&(dst), &(src), sizeof(va_list))
152 sz = vsnprintf(buffer, space - 1, fmt, aq);
153 buffer[space - 1] = '\0';
155 sz = vsnprintf(buffer, space, fmt, aq);
165 (*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
168 if (evbuffer_expand(buf, sz + 1) == -1)
176 evbuffer_add_printf(struct evbuffer *buf, const char *fmt, ...)
182 res = evbuffer_add_vprintf(buf, fmt, ap);
188 /* Reads data from an event buffer and drains the bytes read */
191 evbuffer_remove(struct evbuffer *buf, void *data, size_t datlen)
193 size_t nread = datlen;
194 if (nread >= buf->off)
197 memcpy(data, buf->buffer, nread);
198 evbuffer_drain(buf, nread);
204 * Reads a line terminated by either '\r\n', '\n\r' or '\r' or '\n'.
205 * The returned buffer needs to be freed by the called.
209 evbuffer_readline(struct evbuffer *buffer)
211 u_char *data = EVBUFFER_DATA(buffer);
212 size_t len = EVBUFFER_LENGTH(buffer);
216 for (i = 0; i < len; i++) {
217 if (data[i] == '\r' || data[i] == '\n')
224 if ((line = malloc(i + 1)) == NULL) {
225 fprintf(stderr, "%s: out of memory\n", __func__);
226 evbuffer_drain(buffer, i);
230 memcpy(line, data, i);
234 * Some protocols terminate a line with '\r\n', so check for
238 char fch = data[i], sch = data[i+1];
240 /* Drain one more character if needed */
241 if ( (sch == '\r' || sch == '\n') && sch != fch )
245 evbuffer_drain(buffer, i + 1);
250 /* Adds data to an event buffer */
253 evbuffer_align(struct evbuffer *buf)
255 memmove(buf->orig_buffer, buf->buffer, buf->off);
256 buf->buffer = buf->orig_buffer;
260 /* Expands the available space in the event buffer to at least datlen */
263 evbuffer_expand(struct evbuffer *buf, size_t datlen)
265 size_t need = buf->misalign + buf->off + datlen;
267 /* If we can fit all the data, then we don't have to do anything */
268 if (buf->totallen >= need)
272 * If the misalignment fulfills our data needs, we just force an
273 * alignment to happen. Afterwards, we have enough space.
275 if (buf->misalign >= datlen) {
279 size_t length = buf->totallen;
283 while (length < need)
286 if (buf->orig_buffer != buf->buffer)
288 if ((newbuf = realloc(buf->buffer, length)) == NULL)
291 buf->orig_buffer = buf->buffer = newbuf;
292 buf->totallen = length;
299 evbuffer_add(struct evbuffer *buf, const void *data, size_t datlen)
301 size_t need = buf->misalign + buf->off + datlen;
302 size_t oldoff = buf->off;
304 if (buf->totallen < need) {
305 if (evbuffer_expand(buf, datlen) == -1)
309 memcpy(buf->buffer + buf->off, data, datlen);
312 if (datlen && buf->cb != NULL)
313 (*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
319 evbuffer_drain(struct evbuffer *buf, size_t len)
321 size_t oldoff = buf->off;
323 if (len >= buf->off) {
325 buf->buffer = buf->orig_buffer;
331 buf->misalign += len;
336 /* Tell someone about changes in this buffer */
337 if (buf->off != oldoff && buf->cb != NULL)
338 (*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
343 * Reads data from a file descriptor into a buffer.
346 #define EVBUFFER_MAX_READ 4096
349 evbuffer_read(struct evbuffer *buf, int fd, int howmuch)
352 size_t oldoff = buf->off;
353 int n = EVBUFFER_MAX_READ;
359 if (ioctl(fd, FIONREAD, &n) == -1 || n == 0) {
360 n = EVBUFFER_MAX_READ;
361 } else if (n > EVBUFFER_MAX_READ && n > howmuch) {
363 * It's possible that a lot of data is available for
364 * reading. We do not want to exhaust resources
365 * before the reader has a chance to do something
366 * about it. If the reader does not tell us how much
367 * data we should read, we artifically limit it.
369 if (n > buf->totallen << 2)
370 n = buf->totallen << 2;
371 if (n < EVBUFFER_MAX_READ)
372 n = EVBUFFER_MAX_READ;
375 if (howmuch < 0 || howmuch > n)
378 /* If we don't have FIONREAD, we might waste some space here */
379 if (evbuffer_expand(buf, howmuch) == -1)
382 /* We can append new data at this point */
383 p = buf->buffer + buf->off;
386 n = read(fd, p, howmuch);
392 n = ReadFile((HANDLE)fd, p, howmuch, &dwBytesRead, NULL);
395 if (dwBytesRead == 0)
402 /* Tell someone about changes in this buffer */
403 if (buf->off != oldoff && buf->cb != NULL)
404 (*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
410 evbuffer_write(struct evbuffer *buffer, int fd)
414 DWORD dwBytesWritten;
418 n = write(fd, buffer->buffer, buffer->off);
424 n = WriteFile((HANDLE)fd, buffer->buffer, buffer->off, &dwBytesWritten, NULL);
427 if (dwBytesWritten == 0)
431 evbuffer_drain(buffer, n);
437 evbuffer_find(struct evbuffer *buffer, const u_char *what, size_t len)
439 u_char *search = buffer->buffer, *end = search + buffer->off;
442 while (search < end &&
443 (p = memchr(search, *what, end - search)) != NULL) {
446 if (memcmp(p, what, len) == 0)
454 void evbuffer_setcb(struct evbuffer *buffer,
455 void (*cb)(struct evbuffer *, size_t, size_t, void *),
459 buffer->cbarg = cbarg;