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-rw-r--r--lib/isc/buffer.c542
1 files changed, 542 insertions, 0 deletions
diff --git a/lib/isc/buffer.c b/lib/isc/buffer.c
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+/*
+ * 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_init(isc_buffer_t *b, void *base, unsigned int length) {
+ /*
+ * Make 'b' refer to the 'length'-byte region starting at 'base'.
+ * XXXDCL see the comment in buffer.h about base being const.
+ */
+ ISC__BUFFER_INIT(b, base, length);
+}
+
+void
+isc__buffer_initnull(isc_buffer_t *b) {
+ /*
+ * Initialize a new buffer which has no backing store. This can
+ * later be grown as needed and swapped in place.
+ */
+ ISC__BUFFER_INIT(b, NULL, 0);
+}
+
+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_invalidate(isc_buffer_t *b) {
+ /*
+ * Make 'b' an invalid buffer.
+ */
+ ISC__BUFFER_INVALIDATE(b);
+}
+
+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_region(isc_buffer_t *b, isc_region_t *r) {
+ /*
+ * Make 'r' refer to the region of 'b'.
+ */
+ ISC__BUFFER_REGION(b, r);
+}
+
+void
+isc__buffer_usedregion(const isc_buffer_t *b, isc_region_t *r) {
+ /*
+ * Make 'r' refer to the used region of 'b'.
+ */
+ ISC__BUFFER_USEDREGION(b, r);
+}
+
+void
+isc__buffer_availableregion(isc_buffer_t *b, isc_region_t *r) {
+ /*
+ * Make 'r' refer to the available region of 'b'.
+ */
+ ISC__BUFFER_AVAILABLEREGION(b, r);
+}
+
+void
+isc__buffer_add(isc_buffer_t *b, unsigned int n) {
+ /*
+ * Increase the 'used' region of 'b' by 'n' bytes.
+ */
+ ISC__BUFFER_ADD(b, n);
+}
+
+void
+isc__buffer_subtract(isc_buffer_t *b, unsigned int n) {
+ /*
+ * Decrease the 'used' region of 'b' by 'n' bytes.
+ */
+ ISC__BUFFER_SUBTRACT(b, n);
+}
+
+void
+isc__buffer_clear(isc_buffer_t *b) {
+ /*
+ * Make the used region empty.
+ */
+ ISC__BUFFER_CLEAR(b);
+}
+
+void
+isc__buffer_consumedregion(isc_buffer_t *b, isc_region_t *r) {
+ /*
+ * Make 'r' refer to the consumed region of 'b'.
+ */
+ ISC__BUFFER_CONSUMEDREGION(b, r);
+}
+
+void
+isc__buffer_remainingregion(isc_buffer_t *b, isc_region_t *r) {
+ /*
+ * Make 'r' refer to the remaining region of 'b'.
+ */
+ ISC__BUFFER_REMAININGREGION(b, r);
+}
+
+void
+isc__buffer_activeregion(isc_buffer_t *b, isc_region_t *r) {
+ /*
+ * Make 'r' refer to the active region of 'b'.
+ */
+ ISC__BUFFER_ACTIVEREGION(b, r);
+}
+
+void
+isc__buffer_setactive(isc_buffer_t *b, unsigned int n) {
+ /*
+ * Sets the end of the active region 'n' bytes after current.
+ */
+ ISC__BUFFER_SETACTIVE(b, n);
+}
+
+void
+isc__buffer_first(isc_buffer_t *b) {
+ /*
+ * Make the consumed region empty.
+ */
+ ISC__BUFFER_FIRST(b);
+}
+
+void
+isc__buffer_forward(isc_buffer_t *b, unsigned int n) {
+ /*
+ * Increase the 'consumed' region of 'b' by 'n' bytes.
+ */
+ ISC__BUFFER_FORWARD(b, n);
+}
+
+void
+isc__buffer_back(isc_buffer_t *b, unsigned int n) {
+ /*
+ * Decrease the 'consumed' region of 'b' by 'n' bytes.
+ */
+ ISC__BUFFER_BACK(b, n);
+}
+
+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);
+}
+
+void
+isc__buffer_putuint8(isc_buffer_t *b, uint8_t val) {
+ ISC__BUFFER_PUTUINT8(b, val);
+}
+
+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);
+}
+
+void
+isc__buffer_putuint16(isc_buffer_t *b, uint16_t val) {
+ ISC__BUFFER_PUTUINT16(b, val);
+}
+
+void
+isc__buffer_putuint24(isc_buffer_t *b, uint32_t val) {
+ ISC__BUFFER_PUTUINT24(b, val);
+}
+
+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);
+}
+
+void
+isc__buffer_putuint32(isc_buffer_t *b, uint32_t val) {
+ ISC__BUFFER_PUTUINT32(b, val);
+}
+
+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_putuint48(isc_buffer_t *b, uint64_t val) {
+ isc_result_t result;
+ uint16_t valhi;
+ uint32_t vallo;
+
+ REQUIRE(ISC_BUFFER_VALID(b));
+ if (ISC_UNLIKELY(b->autore)) {
+ result = isc_buffer_reserve(&b, 6);
+ REQUIRE(result == ISC_R_SUCCESS);
+ }
+ REQUIRE(isc_buffer_availablelength(b) >= 6);
+
+ valhi = (uint16_t)(val >> 32);
+ vallo = (uint32_t)(val & 0xFFFFFFFF);
+ ISC__BUFFER_PUTUINT16(b, valhi);
+ ISC__BUFFER_PUTUINT32(b, vallo);
+}
+
+void
+isc__buffer_putmem(isc_buffer_t *b, const unsigned char *base,
+ unsigned int length) {
+ ISC__BUFFER_PUTMEM(b, base, length);
+}
+
+void
+isc__buffer_putstr(isc_buffer_t *b, const char *source) {
+ ISC__BUFFER_PUTSTR(b, source);
+}
+
+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 (ISC_UNLIKELY(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 (ISC_UNLIKELY(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) {
+ unsigned char *bdata;
+ uint64_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);
+ }
+
+ /*
+ * XXXMUKS: This is far more expensive than plain realloc() as
+ * it doesn't remap pages, but does ordinary copy. So is
+ * isc_mem_reallocate(), which has additional issues.
+ */
+ bdata = isc_mem_get((*dynbuffer)->mctx, (unsigned int)len);
+
+ memmove(bdata, (*dynbuffer)->base, (*dynbuffer)->length);
+ isc_mem_put((*dynbuffer)->mctx, (*dynbuffer)->base,
+ (*dynbuffer)->length);
+
+ (*dynbuffer)->base = bdata;
+ (*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 (ISC_UNLIKELY(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);
+}