add

+/*
+ * Copyright (c) 2002, 2003 Niels Provos <provos@citi.umich.edu>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifdef WIN32
+#include <winsock2.h>
+#pragma warning(disable: 4996)
+#else
+#include <unistd.h>
+#endif
+
+#include <stdlib.h>
+#include <assert.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "spwin32buffer.hpp"
+
+struct spwin32buffer *
+spwin32buffer_new(void)
+{
+	struct spwin32buffer *buffer;
+	
+	buffer = (struct spwin32buffer*)calloc(1, sizeof(struct spwin32buffer));
+
+	return (buffer);
+}
+
+void
+spwin32buffer_free(struct spwin32buffer *buffer)
+{
+	if (buffer->orig_buffer != NULL)
+		free(buffer->orig_buffer);
+	free(buffer);
+}
+
+/* 
+ * This is a destructive add.  The data from one buffer moves into
+ * the other buffer.
+ */
+
+#define SWAP(x,y) do { \
+	(x)->buffer = (y)->buffer; \
+	(x)->orig_buffer = (y)->orig_buffer; \
+	(x)->misalign = (y)->misalign; \
+	(x)->totallen = (y)->totallen; \
+	(x)->off = (y)->off; \
+} while (0)
+
+int
+spwin32buffer_add_buffer(struct spwin32buffer *outbuf, struct spwin32buffer *inbuf)
+{
+	int res;
+
+	/* Short cut for better performance */
+	if (outbuf->off == 0) {
+		struct spwin32buffer tmp;
+		size_t oldoff = inbuf->off;
+
+		/* Swap them directly */
+		SWAP(&tmp, outbuf);
+		SWAP(outbuf, inbuf);
+		SWAP(inbuf, &tmp);
+
+		/* 
+		 * Optimization comes with a price; we need to notify the
+		 * buffer if necessary of the changes. oldoff is the amount
+		 * of data that we transfered from inbuf to outbuf
+		 */
+		if (inbuf->off != oldoff && inbuf->cb != NULL)
+			(*inbuf->cb)(inbuf, oldoff, inbuf->off, inbuf->cbarg);
+		if (oldoff && outbuf->cb != NULL)
+			(*outbuf->cb)(outbuf, 0, oldoff, outbuf->cbarg);
+		
+		return (0);
+	}
+
+	res = spwin32buffer_add(outbuf, inbuf->buffer, inbuf->off);
+	if (res == 0) {
+		/* We drain the input buffer on success */
+		spwin32buffer_drain(inbuf, inbuf->off);
+	}
+
+	return (res);
+}
+
+int
+spwin32buffer_add_vprintf(struct spwin32buffer *buf, const char *fmt, va_list ap)
+{
+	char *buffer;
+	size_t space;
+	size_t oldoff = buf->off;
+	int sz;
+	va_list aq;
+
+	/* make sure that at least some space is available */
+	spwin32buffer_expand(buf, 64);
+	for (;;) {
+		size_t used = buf->misalign + buf->off;
+		buffer = (char *)buf->buffer + buf->off;
+		assert(buf->totallen >= used);
+		space = buf->totallen - used;
+
+#ifndef va_copy
+#define	va_copy(dst, src)	memcpy(&(dst), &(src), sizeof(va_list))
+#endif
+		va_copy(aq, ap);
+
+#ifdef WIN32
+		sz = _vsnprintf(buffer, space - 1, fmt, aq);
+		buffer[space - 1] = '\0';
+#else
+		sz = vsnprintf(buffer, space, fmt, aq);
+#endif
+
+		va_end(aq);
+
+		if (sz < 0)
+			return (-1);
+		if (sz < (int)space) {
+			buf->off += sz;
+			if (buf->cb != NULL)
+				(*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
+			return (sz);
+		}
+		if (spwin32buffer_expand(buf, sz + 1) == -1)
+			return (-1);
+
+	}
+	/* NOTREACHED */
+}
+
+int
+spwin32buffer_add_printf(struct spwin32buffer *buf, const char *fmt, ...)
+{
+	int res = -1;
+	va_list ap;
+
+	va_start(ap, fmt);
+	res = spwin32buffer_add_vprintf(buf, fmt, ap);
+	va_end(ap);
+
+	return (res);
+}
+
+/* Reads data from an event buffer and drains the bytes read */
+
+int
+spwin32buffer_remove(struct spwin32buffer *buf, void *data, size_t datlen)
+{
+	size_t nread = datlen;
+	if (nread >= buf->off)
+		nread = buf->off;
+
+	memcpy(data, buf->buffer, nread);
+	spwin32buffer_drain(buf, nread);
+	
+	return (nread);
+}
+
+/*
+ * Reads a line terminated by either '\r\n', '\n\r' or '\r' or '\n'.
+ * The returned buffer needs to be freed by the called.
+ */
+
+char *
+spwin32buffer_readline(struct spwin32buffer *buffer)
+{
+	u_char *data = EVBUFFER_DATA(buffer);
+	size_t len = EVBUFFER_LENGTH(buffer);
+	char *line;
+	unsigned int i;
+
+	for (i = 0; i < len; i++) {
+		if (data[i] == '\r' || data[i] == '\n')
+			break;
+	}
+
+	if (i == len)
+		return (NULL);
+
+	if ((line = (char*)malloc(i + 1)) == NULL) {
+		//fprintf(stderr, "%s: out of memory\n", __func__);
+		spwin32buffer_drain(buffer, i);
+		return (NULL);
+	}
+
+	memcpy(line, data, i);
+	line[i] = '\0';
+
+	/*
+	 * Some protocols terminate a line with '\r\n', so check for
+	 * that, too.
+	 */
+	if ( i < len - 1 ) {
+		char fch = data[i], sch = data[i+1];
+
+		/* Drain one more character if needed */
+		if ( (sch == '\r' || sch == '\n') && sch != fch )
+			i += 1;
+	}
+
+	spwin32buffer_drain(buffer, i + 1);
+
+	return (line);
+}
+
+/* Adds data to an event buffer */
+
+static void
+spwin32buffer_align(struct spwin32buffer *buf)
+{
+	memmove(buf->orig_buffer, buf->buffer, buf->off);
+	buf->buffer = buf->orig_buffer;
+	buf->misalign = 0;
+}
+
+/* Expands the available space in the event buffer to at least datlen */
+
+int
+spwin32buffer_expand(struct spwin32buffer *buf, size_t datlen)
+{
+	size_t need = buf->misalign + buf->off + datlen;
+
+	/* If we can fit all the data, then we don't have to do anything */
+	if (buf->totallen >= need)
+		return (0);
+
+	/*
+	 * If the misalignment fulfills our data needs, we just force an
+	 * alignment to happen.  Afterwards, we have enough space.
+	 */
+	if (buf->misalign >= datlen) {
+		spwin32buffer_align(buf);
+	} else {
+		void *newbuf;
+		size_t length = buf->totallen;
+
+		if (length < 256)
+			length = 256;
+		while (length < need)
+			length <<= 1;
+
+		if (buf->orig_buffer != buf->buffer)
+			spwin32buffer_align(buf);
+		if ((newbuf = realloc(buf->buffer, length)) == NULL)
+			return (-1);
+
+		buf->orig_buffer = buf->buffer = (u_char*)newbuf;
+		buf->totallen = length;
+	}
+
+	return (0);
+}
+
+int
+spwin32buffer_add(struct spwin32buffer *buf, const void *data, size_t datlen)
+{
+	size_t need = buf->misalign + buf->off + datlen;
+	size_t oldoff = buf->off;
+
+	if (buf->totallen < need) {
+		if (spwin32buffer_expand(buf, datlen) == -1)
+			return (-1);
+	}
+
+	memcpy(buf->buffer + buf->off, data, datlen);
+	buf->off += datlen;
+
+	if (datlen && buf->cb != NULL)
+		(*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
+
+	return (0);
+}
+
+void
+spwin32buffer_drain(struct spwin32buffer *buf, size_t len)
+{
+	size_t oldoff = buf->off;
+
+	if (len >= buf->off) {
+		buf->off = 0;
+		buf->buffer = buf->orig_buffer;
+		buf->misalign = 0;
+		goto done;
+	}
+
+	buf->buffer += len;
+	buf->misalign += len;
+
+	buf->off -= len;
+
+ done:
+	/* Tell someone about changes in this buffer */
+	if (buf->off != oldoff && buf->cb != NULL)
+		(*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
+
+}
+
+/*
+ * Reads data from a file descriptor into a buffer.
+ */
+
+#define EVBUFFER_MAX_READ	4096
+
+int
+spwin32buffer_read(struct spwin32buffer *buf, int fd, int howmuch)
+{
+	u_char *p;
+	size_t oldoff = buf->off;
+	int n = EVBUFFER_MAX_READ;
+
+#if defined(FIONREAD)
+#ifdef WIN32
+	long lng = n;
+	if (ioctlsocket(fd, FIONREAD, (unsigned long*)&lng) == -1 || (n=lng) == 0) {
+#else
+	if (ioctl(fd, FIONREAD, &n) == -1 || n == 0) {
+#endif
+		n = EVBUFFER_MAX_READ;
+	} else if (n > EVBUFFER_MAX_READ && n > howmuch) {
+		/*
+		 * It's possible that a lot of data is available for
+		 * reading.  We do not want to exhaust resources
+		 * before the reader has a chance to do something
+		 * about it.  If the reader does not tell us how much
+		 * data we should read, we artifically limit it.
+		 */
+		if (n > (int)buf->totallen << 2)
+			n = buf->totallen << 2;
+		if (n < EVBUFFER_MAX_READ)
+			n = EVBUFFER_MAX_READ;
+	}
+#endif	
+	if (howmuch < 0 || howmuch > n)
+		howmuch = n;
+
+	/* If we don't have FIONREAD, we might waste some space here */
+	if (spwin32buffer_expand(buf, howmuch) == -1)
+		return (-1);
+
+	/* We can append new data at this point */
+	p = buf->buffer + buf->off;
+
+#ifndef WIN32
+	n = read(fd, p, howmuch);
+#else
+	n = recv(fd, (char*)p, howmuch, 0);
+#endif
+	if (n == -1)
+		return (-1);
+	if (n == 0)
+		return (0);
+
+	buf->off += n;
+
+	/* Tell someone about changes in this buffer */
+	if (buf->off != oldoff && buf->cb != NULL)
+		(*buf->cb)(buf, oldoff, buf->off, buf->cbarg);
+
+	return (n);
+}
+
+int
+spwin32buffer_write(struct spwin32buffer *buffer, int fd)
+{
+	int n;
+
+#ifndef WIN32
+	n = write(fd, buffer->buffer, buffer->off);
+#else
+	n = send(fd, (char*)buffer->buffer, buffer->off, 0);
+#endif
+	if (n == -1)
+		return (-1);
+	if (n == 0)
+		return (0);
+	spwin32buffer_drain(buffer, n);
+
+	return (n);
+}
+
+u_char *
+spwin32buffer_find(struct spwin32buffer *buffer, const u_char *what, size_t len)
+{
+	u_char *search = buffer->buffer, *end = search + buffer->off;
+	u_char *p;
+
+	while (search < end &&
+	    (p = (u_char*)memchr(search, *what, end - search)) != NULL) {
+		if (p + len > end)
+			break;
+		if (memcmp(p, what, len) == 0)
+			return (p);
+		search = p + 1;
+	}
+
+	return (NULL);
+}
+
+void spwin32buffer_setcb(struct spwin32buffer *buffer,
+    void (*cb)(struct spwin32buffer *, size_t, size_t, void *),
+    void *cbarg)
+{
+	buffer->cb = cb;
+	buffer->cbarg = cbarg;
+}
+