1 files changed, 352 insertions, 0 deletions
diff --git a/lib/isc/buffer.c b/lib/isc/buffer.c
new file mode 100644
index 0000000..e7e84df
--- /dev/null
+++ b/lib/isc/buffer.c
@@ -0,0 +1,352 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * SPDX-License-Identifier: MPL-2.0
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, you can obtain one at https://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+/*! \file */
+
+#include <inttypes.h>
+#include <stdarg.h>
+#include <stdbool.h>
+
+#include <isc/buffer.h>
+#include <isc/mem.h>
+#include <isc/print.h>
+#include <isc/region.h>
+#include <isc/string.h>
+#include <isc/util.h>
+
+void
+isc_buffer_reinit(isc_buffer_t *b, void *base, unsigned int length) {
+	/*
+	 * Re-initialize the buffer enough to reconfigure the base of the
+	 * buffer.  We will swap in the new buffer, after copying any
+	 * data we contain into the new buffer and adjusting all of our
+	 * internal pointers.
+	 *
+	 * The buffer must not be smaller than the length of the original
+	 * buffer.
+	 */
+	REQUIRE(b->length <= length);
+	REQUIRE(base != NULL);
+	REQUIRE(!b->autore);
+
+	if (b->length > 0U) {
+		(void)memmove(base, b->base, b->length);
+	}
+
+	b->base = base;
+	b->length = length;
+}
+
+void
+isc_buffer_setautorealloc(isc_buffer_t *b, bool enable) {
+	REQUIRE(ISC_BUFFER_VALID(b));
+	REQUIRE(b->mctx != NULL);
+	b->autore = enable;
+}
+
+void
+isc_buffer_compact(isc_buffer_t *b) {
+	unsigned int length;
+	void *src;
+
+	/*
+	 * Compact the used region by moving the remaining region so it occurs
+	 * at the start of the buffer.  The used region is shrunk by the size
+	 * of the consumed region, and the consumed region is then made empty.
+	 */
+
+	REQUIRE(ISC_BUFFER_VALID(b));
+
+	src = isc_buffer_current(b);
+	length = isc_buffer_remaininglength(b);
+	if (length > 0U) {
+		(void)memmove(b->base, src, (size_t)length);
+	}
+
+	if (b->active > b->current) {
+		b->active -= b->current;
+	} else {
+		b->active = 0;
+	}
+	b->current = 0;
+	b->used = length;
+}
+
+uint8_t
+isc_buffer_getuint8(isc_buffer_t *b) {
+	unsigned char *cp;
+	uint8_t result;
+
+	/*
+	 * Read an unsigned 8-bit integer from 'b' and return it.
+	 */
+
+	REQUIRE(ISC_BUFFER_VALID(b));
+	REQUIRE(b->used - b->current >= 1);
+
+	cp = isc_buffer_current(b);
+	b->current += 1;
+	result = ((uint8_t)(cp[0]));
+
+	return (result);
+}
+
+uint16_t
+isc_buffer_getuint16(isc_buffer_t *b) {
+	unsigned char *cp;
+	uint16_t result;
+
+	/*
+	 * Read an unsigned 16-bit integer in network byte order from 'b',
+	 * convert it to host byte order, and return it.
+	 */
+
+	REQUIRE(ISC_BUFFER_VALID(b));
+	REQUIRE(b->used - b->current >= 2);
+
+	cp = isc_buffer_current(b);
+	b->current += 2;
+	result = ((unsigned int)(cp[0])) << 8;
+	result |= ((unsigned int)(cp[1]));
+
+	return (result);
+}
+
+uint32_t
+isc_buffer_getuint32(isc_buffer_t *b) {
+	unsigned char *cp;
+	uint32_t result;
+
+	/*
+	 * Read an unsigned 32-bit integer in network byte order from 'b',
+	 * convert it to host byte order, and return it.
+	 */
+
+	REQUIRE(ISC_BUFFER_VALID(b));
+	REQUIRE(b->used - b->current >= 4);
+
+	cp = isc_buffer_current(b);
+	b->current += 4;
+	result = ((unsigned int)(cp[0])) << 24;
+	result |= ((unsigned int)(cp[1])) << 16;
+	result |= ((unsigned int)(cp[2])) << 8;
+	result |= ((unsigned int)(cp[3]));
+
+	return (result);
+}
+
+uint64_t
+isc_buffer_getuint48(isc_buffer_t *b) {
+	unsigned char *cp;
+	uint64_t result;
+
+	/*
+	 * Read an unsigned 48-bit integer in network byte order from 'b',
+	 * convert it to host byte order, and return it.
+	 */
+
+	REQUIRE(ISC_BUFFER_VALID(b));
+	REQUIRE(b->used - b->current >= 6);
+
+	cp = isc_buffer_current(b);
+	b->current += 6;
+	result = ((int64_t)(cp[0])) << 40;
+	result |= ((int64_t)(cp[1])) << 32;
+	result |= ((int64_t)(cp[2])) << 24;
+	result |= ((int64_t)(cp[3])) << 16;
+	result |= ((int64_t)(cp[4])) << 8;
+	result |= ((int64_t)(cp[5]));
+
+	return (result);
+}
+
+void
+isc_buffer_putdecint(isc_buffer_t *b, int64_t v) {
+	unsigned int l = 0;
+	unsigned char *cp;
+	char buf[21];
+	isc_result_t result;
+
+	REQUIRE(ISC_BUFFER_VALID(b));
+
+	/* xxxwpk do it more low-level way ? */
+	l = snprintf(buf, 21, "%" PRId64, v);
+	RUNTIME_CHECK(l <= 21);
+	if (b->autore) {
+		result = isc_buffer_reserve(&b, l);
+		REQUIRE(result == ISC_R_SUCCESS);
+	}
+	REQUIRE(isc_buffer_availablelength(b) >= l);
+
+	cp = isc_buffer_used(b);
+	memmove(cp, buf, l);
+	b->used += l;
+}
+
+isc_result_t
+isc_buffer_dup(isc_mem_t *mctx, isc_buffer_t **dstp, const isc_buffer_t *src) {
+	isc_buffer_t *dst = NULL;
+	isc_region_t region;
+	isc_result_t result;
+
+	REQUIRE(dstp != NULL && *dstp == NULL);
+	REQUIRE(ISC_BUFFER_VALID(src));
+
+	isc_buffer_usedregion(src, &region);
+
+	isc_buffer_allocate(mctx, &dst, region.length);
+
+	result = isc_buffer_copyregion(dst, &region);
+	RUNTIME_CHECK(result == ISC_R_SUCCESS); /* NOSPACE is impossible */
+	*dstp = dst;
+	return (ISC_R_SUCCESS);
+}
+
+isc_result_t
+isc_buffer_copyregion(isc_buffer_t *b, const isc_region_t *r) {
+	isc_result_t result;
+
+	REQUIRE(ISC_BUFFER_VALID(b));
+	REQUIRE(r != NULL);
+
+	if (b->autore) {
+		result = isc_buffer_reserve(&b, r->length);
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+	}
+
+	if (r->length > isc_buffer_availablelength(b)) {
+		return (ISC_R_NOSPACE);
+	}
+
+	if (r->length > 0U) {
+		memmove(isc_buffer_used(b), r->base, r->length);
+		b->used += r->length;
+	}
+
+	return (ISC_R_SUCCESS);
+}
+
+void
+isc_buffer_allocate(isc_mem_t *mctx, isc_buffer_t **dynbuffer,
+		    unsigned int length) {
+	REQUIRE(dynbuffer != NULL && *dynbuffer == NULL);
+
+	isc_buffer_t *dbuf = isc_mem_get(mctx, sizeof(isc_buffer_t));
+	unsigned char *bdata = isc_mem_get(mctx, length);
+
+	isc_buffer_init(dbuf, bdata, length);
+
+	ENSURE(ISC_BUFFER_VALID(dbuf));
+
+	dbuf->mctx = mctx;
+
+	*dynbuffer = dbuf;
+}
+
+isc_result_t
+isc_buffer_reserve(isc_buffer_t **dynbuffer, unsigned int size) {
+	size_t len;
+
+	REQUIRE(dynbuffer != NULL);
+	REQUIRE(ISC_BUFFER_VALID(*dynbuffer));
+
+	len = (*dynbuffer)->length;
+	if ((len - (*dynbuffer)->used) >= size) {
+		return (ISC_R_SUCCESS);
+	}
+
+	if ((*dynbuffer)->mctx == NULL) {
+		return (ISC_R_NOSPACE);
+	}
+
+	/* Round to nearest buffer size increment */
+	len = size + (*dynbuffer)->used;
+	len = (len + ISC_BUFFER_INCR - 1 - ((len - 1) % ISC_BUFFER_INCR));
+
+	/* Cap at UINT_MAX */
+	if (len > UINT_MAX) {
+		len = UINT_MAX;
+	}
+
+	if ((len - (*dynbuffer)->used) < size) {
+		return (ISC_R_NOMEMORY);
+	}
+
+	(*dynbuffer)->base = isc_mem_reget((*dynbuffer)->mctx,
+					   (*dynbuffer)->base,
+					   (*dynbuffer)->length, len);
+	(*dynbuffer)->length = (unsigned int)len;
+
+	return (ISC_R_SUCCESS);
+}
+
+void
+isc_buffer_free(isc_buffer_t **dynbuffer) {
+	isc_buffer_t *dbuf;
+	isc_mem_t *mctx;
+
+	REQUIRE(dynbuffer != NULL);
+	REQUIRE(ISC_BUFFER_VALID(*dynbuffer));
+	REQUIRE((*dynbuffer)->mctx != NULL);
+
+	dbuf = *dynbuffer;
+	*dynbuffer = NULL; /* destroy external reference */
+	mctx = dbuf->mctx;
+	dbuf->mctx = NULL;
+
+	isc_mem_put(mctx, dbuf->base, dbuf->length);
+	isc_buffer_invalidate(dbuf);
+	isc_mem_put(mctx, dbuf, sizeof(isc_buffer_t));
+}
+
+isc_result_t
+isc_buffer_printf(isc_buffer_t *b, const char *format, ...) {
+	va_list ap;
+	int n;
+	isc_result_t result;
+
+	REQUIRE(ISC_BUFFER_VALID(b));
+
+	va_start(ap, format);
+	n = vsnprintf(NULL, 0, format, ap);
+	va_end(ap);
+
+	if (n < 0) {
+		return (ISC_R_FAILURE);
+	}
+
+	if (b->autore) {
+		result = isc_buffer_reserve(&b, n + 1);
+		if (result != ISC_R_SUCCESS) {
+			return (result);
+		}
+	}
+
+	if (isc_buffer_availablelength(b) < (unsigned int)n + 1) {
+		return (ISC_R_NOSPACE);
+	}
+
+	va_start(ap, format);
+	n = vsnprintf(isc_buffer_used(b), n + 1, format, ap);
+	va_end(ap);
+
+	if (n < 0) {
+		return (ISC_R_FAILURE);
+	}
+
+	b->used += n;
+
+	return (ISC_R_SUCCESS);
+}