net: tcp: Rework data queueing

include/zephyr/net/net_pkt.h

@@ -1707,6 +1707,13 @@ int net_pkt_alloc_buffer_debug(struct net_pkt *pkt,
 	net_pkt_alloc_buffer_debug(_pkt, _size, _proto, _timeout,	\
 				   __func__, __LINE__)
 
+int net_pkt_alloc_buffer_raw_debug(struct net_pkt *pkt, size_t size,
+				   k_timeout_t timeout,
+				   const char *caller, int line);
+#define net_pkt_alloc_buffer_raw(_pkt, _size, _timeout)	\
+	net_pkt_alloc_buffer_raw_debug(_pkt, _size, _timeout,	\
+				       __func__, __LINE__)
+
 struct net_pkt *net_pkt_alloc_with_buffer_debug(struct net_if *iface,
 						size_t size,
 						sa_family_t family,
@@ -1821,6 +1828,24 @@ int net_pkt_alloc_buffer(struct net_pkt *pkt,
 			 k_timeout_t timeout);
 #endif
 
+/**
+ * @brief Allocate buffer for a net_pkt, of specified size, w/o any additional
+ *        preconditions
+ *
+ * @details: The actual buffer size may be larger than requested one if fixed
+ *           size buffers are in use.
+ *
+ * @param pkt     The network packet requiring buffer to be allocated.
+ * @param size    The size of buffer being requested.
+ * @param timeout Maximum time to wait for an allocation.
+ *
+ * @return 0 on success, negative errno code otherwise.
+ */
+#if !defined(NET_PKT_DEBUG_ENABLED)
+int net_pkt_alloc_buffer_raw(struct net_pkt *pkt, size_t size,
+			     k_timeout_t timeout);
+#endif
+
 /**
  * @brief Allocate a network packet and buffer at once
  *

subsys/net/ip/net_context.c

@@ -1713,7 +1713,7 @@ static int context_sendto(struct net_context *context,
 {
 	const struct msghdr *msghdr = NULL;
 	struct net_if *iface;
-	struct net_pkt *pkt;
+	struct net_pkt *pkt = NULL;
 	size_t tmp_len;
 	int ret;
 
@@ -1935,6 +1935,15 @@ static int context_sendto(struct net_context *context,
 		return -ENETDOWN;
 	}
 
+	context->send_cb = cb;
+	context->user_data = user_data;
+
+	if (IS_ENABLED(CONFIG_NET_TCP) &&
+	    net_context_get_proto(context) == IPPROTO_TCP &&
+	    !net_if_is_ip_offloaded(net_context_get_iface(context))) {
+		goto skip_alloc;
+	}
+
 	pkt = context_alloc_pkt(context, len, PKT_WAIT_TIME);
 	if (!pkt) {
 		NET_ERR("Failed to allocate net_pkt");
@@ -1953,9 +1962,6 @@ static int context_sendto(struct net_context *context,
 		len = tmp_len;
 	}
 
-	context->send_cb = cb;
-	context->user_data = user_data;
-
 	if (IS_ENABLED(CONFIG_NET_CONTEXT_PRIORITY)) {
 		uint8_t priority;
 
@@ -1977,6 +1983,7 @@ static int context_sendto(struct net_context *context,
 		}
 	}
 
+skip_alloc:
 	if (IS_ENABLED(CONFIG_NET_OFFLOAD) &&
 	    net_if_is_ip_offloaded(net_context_get_iface(context))) {
 		ret = context_write_data(pkt, buf, len, msghdr);
@@ -2008,16 +2015,12 @@ static int context_sendto(struct net_context *context,
 	} else if (IS_ENABLED(CONFIG_NET_TCP) &&
 		   net_context_get_proto(context) == IPPROTO_TCP) {
 
-		ret = context_write_data(pkt, buf, len, msghdr);
+		ret = net_tcp_queue(context, buf, len, msghdr);
 		if (ret < 0) {
 			goto fail;
 		}
 
-		net_pkt_cursor_init(pkt);
-		ret = net_tcp_queue_data(context, pkt);
-		if (ret < 0) {
-			goto fail;
-		}
+		len = ret;
 
 		ret = net_tcp_send_data(context, cb, user_data);
 	} else if (IS_ENABLED(CONFIG_NET_SOCKETS_PACKET) &&
@@ -2073,7 +2076,9 @@ static int context_sendto(struct net_context *context,
 
 	return len;
 fail:
-	net_pkt_unref(pkt);
+	if (pkt != NULL) {
+		net_pkt_unref(pkt);
+	}
 
 	return ret;
 }

subsys/net/ip/net_pkt.c

@@ -1197,6 +1197,67 @@ int net_pkt_alloc_buffer(struct net_pkt *pkt,
 	return 0;
 }
 
+
+#if NET_LOG_LEVEL >= LOG_LEVEL_DBG
+int net_pkt_alloc_buffer_raw_debug(struct net_pkt *pkt, size_t size,
+				   k_timeout_t timeout, const char *caller,
+				   int line)
+#else
+int net_pkt_alloc_buffer_raw(struct net_pkt *pkt, size_t size,
+			     k_timeout_t timeout)
+#endif
+{
+	struct net_buf_pool *pool = NULL;
+	struct net_buf *buf;
+
+	if (size == 0) {
+		return 0;
+	}
+
+	if (k_is_in_isr()) {
+		timeout = K_NO_WAIT;
+	}
+
+	NET_DBG("Data allocation size %zu", size);
+
+	if (pkt->context) {
+		pool = get_data_pool(pkt->context);
+	}
+
+	if (!pool) {
+		pool = pkt->slab == &tx_pkts ? &tx_bufs : &rx_bufs;
+	}
+
+#if NET_LOG_LEVEL >= LOG_LEVEL_DBG
+	buf = pkt_alloc_buffer(pool, size, timeout, caller, line);
+#else
+	buf = pkt_alloc_buffer(pool, size, timeout);
+#endif
+
+	if (!buf) {
+#if NET_LOG_LEVEL >= LOG_LEVEL_DBG
+		NET_ERR("Data buffer (%zd) allocation failed (%s:%d)",
+			size, caller, line);
+#else
+		NET_ERR("Data buffer (%zd) allocation failed.", size);
+#endif
+		return -ENOMEM;
+	}
+
+	net_pkt_append_buffer(pkt, buf);
+
+#if IS_ENABLED(CONFIG_NET_BUF_FIXED_DATA_SIZE)
+	/* net_buf allocators shrink the buffer size to the requested size.
+	 * We don't want this behavior here, so restore the real size of the
+	 * last fragment.
+	 */
+	buf = net_buf_frag_last(buf);
+	buf->size = CONFIG_NET_BUF_DATA_SIZE;
+#endif
+
+	return 0;
+}
+
 #if NET_LOG_LEVEL >= LOG_LEVEL_DBG
 static struct net_pkt *pkt_alloc(struct k_mem_slab *slab, k_timeout_t timeout,
 				 const char *caller, int line)