Adding upstream version 3.2.6.upstream/3.2.6upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 266 insertions, 0 deletions

diff --git a/src/libknot/xdp/tcp_iobuf.c b/src/libknot/xdp/tcp_iobuf.c
new file mode 100644
index 0000000..88ebcc3
--- /dev/null
+++ b/src/libknot/xdp/tcp_iobuf.c
@@ -0,0 +1,266 @@
+/*  Copyright (C) 2022 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "libknot/xdp/tcp_iobuf.h"
+
+#include "contrib/macros.h"
+#include "libknot/attribute.h"
+#include "libknot/endian.h"
+#include "libknot/error.h"
+
+static void iov_clear(struct iovec *iov)
+{
+	free(iov->iov_base);
+	memset(iov, 0, sizeof(*iov));
+}
+
+static void iov_inc(struct iovec *iov, size_t shift)
+{
+	assert(shift <= iov->iov_len);
+	iov->iov_base += shift;
+	iov->iov_len -= shift;
+}
+
+/*! \brief Strip 2-byte length prefix from a payload. */
+static void iov_inc2(struct iovec *iov)
+{
+	iov_inc(iov, sizeof(uint16_t));
+}
+
+static size_t tcp_payload_len(const struct iovec *payload)
+{
+	assert(payload->iov_len >= 2);
+	uint16_t val;
+	memcpy(&val, payload->iov_base, sizeof(val));
+	return be16toh(val) + sizeof(val);
+}
+
+static bool iov_inc_pf(struct iovec *iov)
+{
+	size_t shift = tcp_payload_len(iov);
+	if (iov->iov_len >= shift) {
+		iov_inc(iov, shift);
+		return true;
+	} else {
+		return false;
+	}
+}
+
+static size_t iov_count(const struct iovec *iov)
+{
+	size_t res = 0;
+	struct iovec tmp = *iov;
+	while (tmp.iov_len >= sizeof(uint16_t) && iov_inc_pf(&tmp)) {
+		res++;
+	}
+	return res;
+}
+
+static void iov_append(struct iovec *what, const struct iovec *with)
+{
+	// NOTE: what->iov_base must be pre-allocated large enough
+	memcpy(what->iov_base + what->iov_len, with->iov_base, with->iov_len);
+	what->iov_len += with->iov_len;
+}
+
+_public_
+int knot_tcp_inbuf_update(struct iovec *buffer, struct iovec data,
+                          struct iovec **inbufs, size_t *inbufs_count,
+                          size_t *buffers_total)
+{
+	size_t res_count = 0;
+	struct iovec *res = NULL, *cur = NULL;
+
+	*inbufs = NULL;
+	*inbufs_count = 0;
+
+	if (data.iov_len < 1) {
+		return KNOT_EOK;
+	}
+	if (buffer->iov_len == 1) {
+		((uint8_t *)buffer->iov_base)[1] = ((uint8_t *)data.iov_base)[0];
+		buffer->iov_len++;
+		iov_inc(&data, 1);
+		if (data.iov_len < 1) {
+			return KNOT_EOK;
+		}
+	}
+	if (buffer->iov_len > 0) {
+		size_t buffer_req = tcp_payload_len(buffer);
+		assert(buffer_req > buffer->iov_len);
+		struct iovec data_use = { data.iov_base, buffer_req - buffer->iov_len };
+		if (data_use.iov_len <= data.iov_len) { // usable payload combined from buffer and data ---> res[0] allocated tohether with res
+			iov_inc(&data, data_use.iov_len);
+
+			res_count = 1 + iov_count(&data);
+			res = malloc(res_count * sizeof(*res) + buffer_req);
+			if (res == NULL) {
+				return KNOT_ENOMEM;
+			}
+			res[0].iov_base = (void *)(res + res_count);
+			res[0].iov_len = 0;
+			iov_append(&res[0], buffer);
+			iov_append(&res[0], &data_use);
+			assert(res[0].iov_len == buffer_req);
+			iov_inc2(&res[0]);
+
+			cur = &res[1];
+			*buffers_total -= buffer->iov_len;
+			iov_clear(buffer);
+		} else { // just extend the buffer with data
+			void *bufnew = realloc(buffer->iov_base, buffer->iov_len + data.iov_len);
+			if (bufnew == NULL) {
+				return KNOT_ENOMEM;
+			}
+			buffer->iov_base = bufnew;
+			iov_append(buffer, &data);
+			*buffers_total += data.iov_len;
+			return KNOT_EOK;
+		}
+	} else { // just allocate res
+		res_count = iov_count(&data);
+		if (res_count > 0) {
+			res = malloc(res_count * sizeof(*res));
+			if (res == NULL) {
+				return KNOT_ENOMEM;
+			}
+			cur = &res[0];
+		}
+	}
+
+	void *last;
+	while (data.iov_len > 1) {
+		last = data.iov_base;
+		if (!iov_inc_pf(&data)) {
+			break;
+		}
+		assert(cur);
+		cur->iov_base = last;
+		cur->iov_len = data.iov_base - last;
+		iov_inc2(cur);
+		cur++;
+	}
+	assert(cur == ((res_count) ? res + res_count : res));
+
+	// store the final incomplete payload to buffer
+	if (data.iov_len > 0) {
+		assert(buffer->iov_base == NULL);
+		buffer->iov_base = malloc(MAX(data.iov_len, 2));
+		if (buffer->iov_base == NULL) {
+			free(res);
+			return KNOT_ENOMEM;
+		}
+		*buffers_total += MAX(data.iov_len, 2);
+		buffer->iov_len = 0;
+		iov_append(buffer, &data);
+	}
+
+	*inbufs = res;
+	*inbufs_count = res_count;
+
+	return KNOT_EOK;
+}
+
+_public_
+int knot_tcp_outbufs_add(knot_tcp_outbuf_t **bufs, uint8_t *data, size_t len,
+                         bool ignore_lastbyte, uint32_t mss, size_t *outbufs_total)
+{
+	if (len > UINT16_MAX) {
+		return KNOT_ELIMIT;
+	}
+	knot_tcp_outbuf_t **end = bufs;
+	while (*end != NULL) { // NOTE: this can be optimized by adding "end" pointer for the price of larger knot_tcp_conn_t struct
+		end = &(*end)->next;
+	}
+	uint16_t prefix = htobe16(len), prefix_len = sizeof(prefix);
+	while (len > 0) {
+		uint16_t newlen = MIN(len + prefix_len, mss);
+		knot_tcp_outbuf_t *newob = calloc(1, sizeof(*newob) + newlen);
+		if (newob == NULL) {
+			return KNOT_ENOMEM;
+		}
+		*outbufs_total += sizeof(*newob) + newlen;
+		newob->len = newlen;
+		if (ignore_lastbyte) {
+			newob->len--;
+		}
+		memcpy(newob->bytes, &prefix, prefix_len);
+		memcpy(newob->bytes + prefix_len, data, newlen - prefix_len);
+
+		*end = newob;
+		end = &newob->next;
+
+		data += newlen - prefix_len;
+		len -= newlen - prefix_len;
+
+		prefix_len = 0;
+	}
+	return KNOT_EOK;
+}
+
+static bool seqno_lower(uint32_t seqno, uint32_t ackno, uint32_t ackno_min)
+{
+	if (ackno_min <= ackno) {
+		return (seqno >= ackno_min && seqno <= ackno);
+	} else {
+		return (seqno >= ackno_min || seqno <= ackno);
+	}
+}
+
+_public_
+void knot_tcp_outbufs_ack(knot_tcp_outbuf_t **bufs, uint32_t ackno, size_t *outbufs_total)
+{
+	uint32_t ackno_min = ackno - (UINT32_MAX / 2); // FIXME better?
+	while (*bufs != NULL && (*bufs)->sent && seqno_lower((*bufs)->seqno + (*bufs)->len, ackno, ackno_min)) {
+		knot_tcp_outbuf_t *tofree = *bufs;
+		*bufs = tofree->next;
+		*outbufs_total -= tofree->len + sizeof(*tofree);
+		free(tofree);
+	}
+}
+
+_public_
+void knot_tcp_outbufs_can_send(knot_tcp_outbuf_t *bufs, ssize_t window_size, bool resend,
+                               knot_tcp_outbuf_t **send_start, size_t *send_count)
+{
+	*send_count = 0;
+	*send_start = bufs;
+	while (*send_start != NULL && (*send_start)->sent && !resend) {
+		window_size -= (*send_start)->len;
+		*send_start = (*send_start)->next;
+	}
+
+	knot_tcp_outbuf_t *can_send = *send_start;
+	while (can_send != NULL && window_size >= can_send->len) {
+		(*send_count)++;
+		window_size -= can_send->len;
+		can_send = can_send->next;
+	}
+}
+
+_public_
+size_t knot_tcp_outbufs_usage(knot_tcp_outbuf_t *bufs)
+{
+	size_t res = 0;
+	for (knot_tcp_outbuf_t *i = bufs; i != NULL; i = i->next) {
+		res += i->len + sizeof(*i);
+	}
+	return res;
+}