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>
63 struct evbuffer *buffer;
65 buffer = calloc(1, sizeof(struct evbuffer));
71 evbuffer_free(struct evbuffer *buffer)
73 if (buffer->orig_buffer != NULL)
74 free(buffer->orig_buffer);
79 * This is a destructive add. The data from one buffer moves into
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; \
92 evbuffer_add_buffer(struct evbuffer *outbuf, struct evbuffer *inbuf)
96 /* Short cut for better performance */
97 if (outbuf->off == 0) {
99 size_t oldoff = inbuf->off;
101 /* Swap them directly */
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
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);
119 res = evbuffer_add(outbuf, inbuf->buffer, inbuf->off);
121 /* We drain the input buffer on success */
122 evbuffer_drain(inbuf, inbuf->off);
129 evbuffer_add_vprintf(struct evbuffer *buf, const char *fmt, va_list ap)
133 size_t oldoff = buf->off;
138 buffer = (char *)buf->buffer + buf->off;
139 space = buf->totallen - buf->misalign - buf->off;
142 #define va_copy(dst, src) memcpy(&(dst), &(src), sizeof(va_list))
147 sz = vsnprintf(buffer, space - 1, fmt, aq);
148 buffer[space - 1] = '\0';
150 sz = vsnprintf(buffer, space, fmt, aq);
160 (*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
163 if (evbuffer_expand(buf, sz + 1) == -1)
171 evbuffer_add_printf(struct evbuffer *buf, const char *fmt, ...)
177 res = evbuffer_add_vprintf(buf, fmt, ap);
183 /* Reads data from an event buffer and drains the bytes read */
186 evbuffer_remove(struct evbuffer *buf, void *data, size_t datlen)
188 size_t nread = datlen;
189 if (nread >= buf->off)
192 memcpy(data, buf->buffer, nread);
193 evbuffer_drain(buf, nread);
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.
204 evbuffer_readline(struct evbuffer *buffer)
206 u_char *data = EVBUFFER_DATA(buffer);
207 size_t len = EVBUFFER_LENGTH(buffer);
211 for (i = 0; i < len; i++) {
212 if (data[i] == '\r' || data[i] == '\n')
219 if ((line = malloc(i + 1)) == NULL) {
220 fprintf(stderr, "%s: out of memory\n", __func__);
221 evbuffer_drain(buffer, i);
225 memcpy(line, data, i);
229 * Some protocols terminate a line with '\r\n', so check for
233 char fch = data[i], sch = data[i+1];
235 /* Drain one more character if needed */
236 if ( (sch == '\r' || sch == '\n') && sch != fch )
240 evbuffer_drain(buffer, i + 1);
245 /* Adds data to an event buffer */
248 evbuffer_align(struct evbuffer *buf)
250 memmove(buf->orig_buffer, buf->buffer, buf->off);
251 buf->buffer = buf->orig_buffer;
255 /* Expands the available space in the event buffer to at least datlen */
258 evbuffer_expand(struct evbuffer *buf, size_t datlen)
260 size_t need = buf->misalign + buf->off + datlen;
262 /* If we can fit all the data, then we don't have to do anything */
263 if (buf->totallen >= need)
267 * If the misalignment fulfills our data needs, we just force an
268 * alignment to happen. Afterwards, we have enough space.
270 if (buf->misalign >= datlen) {
274 size_t length = buf->totallen;
278 while (length < need)
281 if (buf->orig_buffer != buf->buffer)
283 if ((newbuf = realloc(buf->buffer, length)) == NULL)
286 buf->orig_buffer = buf->buffer = newbuf;
287 buf->totallen = length;
294 evbuffer_add(struct evbuffer *buf, const void *data, size_t datlen)
296 size_t need = buf->misalign + buf->off + datlen;
297 size_t oldoff = buf->off;
299 if (buf->totallen < need) {
300 if (evbuffer_expand(buf, datlen) == -1)
304 memcpy(buf->buffer + buf->off, data, datlen);
307 if (datlen && buf->cb != NULL)
308 (*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
314 evbuffer_drain(struct evbuffer *buf, size_t len)
316 size_t oldoff = buf->off;
318 if (len >= buf->off) {
320 buf->buffer = buf->orig_buffer;
326 buf->misalign += len;
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);
338 * Reads data from a file descriptor into a buffer.
341 #define EVBUFFER_MAX_READ 4096
344 evbuffer_read(struct evbuffer *buf, int fd, int howmuch)
347 size_t oldoff = buf->off;
348 int n = EVBUFFER_MAX_READ;
354 if (ioctl(fd, FIONREAD, &n) == -1 || n == 0) {
355 n = EVBUFFER_MAX_READ;
356 } else if (n > EVBUFFER_MAX_READ && n > howmuch) {
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.
364 if (n > buf->totallen << 2)
365 n = buf->totallen << 2;
366 if (n < EVBUFFER_MAX_READ)
367 n = EVBUFFER_MAX_READ;
370 if (howmuch < 0 || howmuch > n)
373 /* If we don't have FIONREAD, we might waste some space here */
374 if (evbuffer_expand(buf, howmuch) == -1)
377 /* We can append new data at this point */
378 p = buf->buffer + buf->off;
381 n = read(fd, p, howmuch);
387 n = ReadFile((HANDLE)fd, p, howmuch, &dwBytesRead, NULL);
390 if (dwBytesRead == 0)
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);
405 evbuffer_write(struct evbuffer *buffer, int fd)
409 DWORD dwBytesWritten;
413 n = write(fd, buffer->buffer, buffer->off);
419 n = WriteFile((HANDLE)fd, buffer->buffer, buffer->off, &dwBytesWritten, NULL);
422 if (dwBytesWritten == 0)
426 evbuffer_drain(buffer, n);
432 evbuffer_find(struct evbuffer *buffer, const u_char *what, size_t len)
434 size_t remain = buffer->off;
435 u_char *search = buffer->buffer;
438 while ((p = memchr(search, *what, remain)) != NULL) {
439 remain = buffer->off - (size_t)(search - buffer->buffer);
442 if (memcmp(p, what, len) == 0)
450 void evbuffer_setcb(struct evbuffer *buffer,
451 void (*cb)(struct evbuffer *, size_t, size_t, void *),
455 buffer->cbarg = cbarg;