From 394ca9bb707bbcccaf01db065c5b393e42f3c7a6 Mon Sep 17 00:00:00 2001
From: Cla Mattia Galliard <cla-mattia.galliard@zuehlke.com>
Date: Fri, 21 Feb 2025 09:08:02 +0100
Subject: [PATCH] net: Add timeout to various send functions

Timeout can be used to early drop some request for arp and icmp to avoid
being slowed when in a flood situation.

Signed-off-by: Cla Mattia Galliard <cla-mattia.galliard@zuehlke.com>
---
 include/zephyr/net/net_core.h               | 17 ++++++++++++++-
 include/zephyr/net/net_if.h                 | 23 ++++++++++++++++++++-
 subsys/net/ip/icmp.c                        |  4 ++--
 subsys/net/ip/icmpv4.c                      |  4 ++--
 subsys/net/ip/icmpv6.c                      |  4 ++--
 subsys/net/ip/ipv4_acd.c                    |  4 ++--
 subsys/net/ip/net_context.c                 |  2 +-
 subsys/net/ip/net_core.c                    |  8 +++++--
 subsys/net/ip/net_if.c                      | 16 +++++++++++---
 subsys/net/ip/net_private.h                 |  2 +-
 subsys/net/ip/net_tc.c                      |  4 ++--
 subsys/net/l2/ethernet/arp.c                |  6 ++++--
 subsys/net/l2/ethernet/bridge.c             |  2 +-
 subsys/net/l2/ethernet/ethernet.c           |  4 ++--
 subsys/net/l2/ethernet/gptp/gptp_messages.c | 12 +++++------
 subsys/net/l2/ethernet/lldp/lldp.c          |  4 +++-
 subsys/net/lib/capture/capture.c            |  2 +-
 17 files changed, 86 insertions(+), 32 deletions(-)

diff --git a/include/zephyr/net/net_core.h b/include/zephyr/net/net_core.h
index 7cd9a1cb15f0..62eaa09de6bf 100644
--- a/include/zephyr/net/net_core.h
+++ b/include/zephyr/net/net_core.h
@@ -128,7 +128,7 @@ int net_recv_data(struct net_if *iface, struct net_pkt *pkt);
  *
  * @details Send data to network. This should not be used normally by
  * applications as it requires that the network packet is properly
- * constructed.
+ * constructed. Equivalent to net_try_send_data with infinite timeout.
  *
  * @param pkt Network packet.
  *
@@ -137,6 +137,21 @@ int net_recv_data(struct net_if *iface, struct net_pkt *pkt);
  */
 int net_send_data(struct net_pkt *pkt);
 
+/**
+ * @brief Try sending data to network.
+ *
+ * @details Send data to network. This should not be used normally by
+ * applications as it requires that the network packet is properly
+ * constructed.
+ *
+ * @param pkt Network packet.
+ * @param timeout Timeout for send.
+ *
+ * @return 0 if ok, <0 if error. If <0 is returned, then the caller needs
+ * to unref the pkt in order to avoid memory leak.
+ */
+int net_try_send_data(struct net_pkt *pkt, k_timeout timeout)
+
 /** @cond INTERNAL_HIDDEN */
 
 /* Some helper defines for traffic class support */
diff --git a/include/zephyr/net/net_if.h b/include/zephyr/net/net_if.h
index c8cbd4496aed..4460db65f11c 100644
--- a/include/zephyr/net/net_if.h
+++ b/include/zephyr/net/net_if.h
@@ -914,13 +914,25 @@ static inline enum net_if_oper_state net_if_oper_state(struct net_if *iface)
 /**
  * @brief Send a packet through a net iface
  *
+ * This is equivalent to net_if_try_queue_tx with an infinite timeout
  * @param iface Pointer to a network interface structure
  * @param pkt Pointer to a net packet to send
  *
- * return verdict about the packet
+ * @return verdict about the packet
  */
 enum net_verdict net_if_send_data(struct net_if *iface, struct net_pkt *pkt);
 
+/**
+ * @brief Try sending a packet through a net iface
+ *
+ * @param iface Pointer to a network interface structure
+ * @param pkt Pointer to a net packet to send
+ * @param timeout timeout for attempting to send
+ *
+ * @return verdict about the packet
+ */
+enum net_verdict net_if_try_send_data(struct net_if *iface, struct net_pkt *pkt, k_timeout timeout);
+
 /**
  * @brief Get a pointer to the interface L2
  *
@@ -982,11 +994,20 @@ static inline const struct device *net_if_get_device(struct net_if *iface)
 /**
  * @brief Queue a packet to the net interface TX queue
  *
+ * This is equivalent to net_if_try_queue_tx with an infinite timeout
  * @param iface Pointer to a network interface structure
  * @param pkt Pointer to a net packet to queue
  */
 void net_if_queue_tx(struct net_if *iface, struct net_pkt *pkt);
 
+/**
+ * @brief Try enqueuing a packet to the net interface TX queue
+ *
+ * @param iface Pointer to a network interface structure
+ * @param pkt Pointer to a net packet to queue
+ */
+void net_if_try_queue_tx(struct net_if *iface, struct net_pkt *pkt, k_timeout timeout);
+
 /**
  * @brief Return the IP offload status
  *
diff --git a/subsys/net/ip/icmp.c b/subsys/net/ip/icmp.c
index e8553726271e..12d2f0229128 100644
--- a/subsys/net/ip/icmp.c
+++ b/subsys/net/ip/icmp.c
@@ -207,7 +207,7 @@ static int send_icmpv4_echo_request(struct net_icmp_ctx *ctx,
 	ctx->user_data = user_data;
 	ctx->iface = iface;
 
-	if (net_send_data(pkt) >= 0) {
+	if (net_try_send_data(pkt, K_NO_WAIT) >= 0) {
 		net_stats_update_icmp_sent(iface);
 		return 0;
 	}
@@ -330,7 +330,7 @@ static int send_icmpv6_echo_request(struct net_icmp_ctx *ctx,
 	ctx->user_data = user_data;
 	ctx->iface = iface;
 
-	if (net_send_data(pkt) >= 0) {
+	if (net_try_send_data(pkt, K_NO_WAIT) >= 0) {
 		net_stats_update_icmp_sent(iface);
 		return 0;
 	}
diff --git a/subsys/net/ip/icmpv4.c b/subsys/net/ip/icmpv4.c
index cc25e572dd4c..3d616bf15b61 100644
--- a/subsys/net/ip/icmpv4.c
+++ b/subsys/net/ip/icmpv4.c
@@ -493,7 +493,7 @@ static int icmpv4_handle_echo_request(struct net_icmp_ctx *ctx,
 		net_sprint_ipv4_addr(src),
 		net_sprint_ipv4_addr(&ip_hdr->src));
 
-	if (net_send_data(reply) < 0) {
+	if (net_try_send_data(reply, K_NO_WAIT) < 0) {
 		goto drop;
 	}
 
@@ -588,7 +588,7 @@ int net_icmpv4_send_error(struct net_pkt *orig, uint8_t type, uint8_t code)
 		net_sprint_ipv4_addr(&ip_hdr->dst),
 		net_sprint_ipv4_addr(&ip_hdr->src));
 
-	if (net_send_data(pkt) >= 0) {
+	if (net_try_send_data(pkt, K_NO_WAIT) >= 0) {
 		net_stats_update_icmp_sent(net_pkt_iface(orig));
 		return 0;
 	}
diff --git a/subsys/net/ip/icmpv6.c b/subsys/net/ip/icmpv6.c
index 048521e1c12b..1fd712940386 100644
--- a/subsys/net/ip/icmpv6.c
+++ b/subsys/net/ip/icmpv6.c
@@ -169,7 +169,7 @@ static int icmpv6_handle_echo_request(struct net_icmp_ctx *ctx,
 		net_sprint_ipv6_addr(src),
 		net_sprint_ipv6_addr(&ip_hdr->src));
 
-	if (net_send_data(reply) < 0) {
+	if (net_try_send_data(reply, K_NO_WAIT) < 0) {
 		goto drop;
 	}
 
@@ -319,7 +319,7 @@ int net_icmpv6_send_error(struct net_pkt *orig, uint8_t type, uint8_t code,
 		net_sprint_ipv6_addr(src),
 		net_sprint_ipv6_addr(&ip_hdr->src));
 
-	if (net_send_data(pkt) >= 0) {
+	if (net_try_send_data(pkt, K_NO_WAIT) >= 0) {
 		net_stats_update_icmp_sent(net_pkt_iface(pkt));
 		return 0;
 	}
diff --git a/subsys/net/ip/ipv4_acd.c b/subsys/net/ip/ipv4_acd.c
index 3cb1d2c6f952..cb787aca950d 100644
--- a/subsys/net/ip/ipv4_acd.c
+++ b/subsys/net/ip/ipv4_acd.c
@@ -103,7 +103,7 @@ static void ipv4_acd_send_probe(struct net_if_addr *ifaddr)
 		return;
 	}
 
-	if (net_if_send_data(iface, pkt) == NET_DROP) {
+	if (net_if_try_send_data(iface, pkt, K_FOREVER) == NET_DROP) {
 		net_pkt_unref(pkt);
 	}
 }
@@ -120,7 +120,7 @@ static void ipv4_acd_send_announcement(struct net_if_addr *ifaddr)
 		return;
 	}
 
-	if (net_if_send_data(iface, pkt) == NET_DROP) {
+	if (net_if_try_send_data(iface, pkt, K_FOREVER) == NET_DROP) {
 		net_pkt_unref(pkt);
 	}
 }
diff --git a/subsys/net/ip/net_context.c b/subsys/net/ip/net_context.c
index 1edbea992ab3..f5ece03cb5d5 100644
--- a/subsys/net/ip/net_context.c
+++ b/subsys/net/ip/net_context.c
@@ -2609,7 +2609,7 @@ static int context_sendto(struct net_context *context,
 			net_pkt_set_ll_proto_type(pkt,
 						  ntohs(ll_dst_addr->sll_protocol));
 
-			net_if_queue_tx(net_pkt_iface(pkt), pkt);
+			net_if_try_queue_tx(net_pkt_iface(pkt), pkt, timeout);
 		}
 	} else if (IS_ENABLED(CONFIG_NET_SOCKETS_CAN) && family == AF_CAN &&
 		   net_context_get_proto(context) == CAN_RAW) {
diff --git a/subsys/net/ip/net_core.c b/subsys/net/ip/net_core.c
index 4c22e10f35a2..eb6a0901dd28 100644
--- a/subsys/net/ip/net_core.c
+++ b/subsys/net/ip/net_core.c
@@ -363,8 +363,12 @@ static inline int check_ip(struct net_pkt *pkt)
 	return ret;
 }
 
-/* Called when data needs to be sent to network */
 int net_send_data(struct net_pkt *pkt)
+{
+	return net_try_send_data(pkt, K_FOREVER);
+}
+
+int net_try_send_data(struct net_pkt *pkt, k_timeout timeout)
 {
 	int status;
 	int ret;
@@ -407,7 +411,7 @@ int net_send_data(struct net_pkt *pkt)
 		goto err;
 	}
 
-	if (net_if_send_data(net_pkt_iface(pkt), pkt) == NET_DROP) {
+	if (net_if_try_send_data(net_pkt_iface(pkt), pkt, timeout) == NET_DROP) {
 		ret = -EIO;
 		goto err;
 	}
diff --git a/subsys/net/ip/net_if.c b/subsys/net/ip/net_if.c
index 53ff75ec4a62..85df1e1b10cc 100644
--- a/subsys/net/ip/net_if.c
+++ b/subsys/net/ip/net_if.c
@@ -343,6 +343,11 @@ void net_process_tx_packet(struct net_pkt *pkt)
 }
 
 void net_if_queue_tx(struct net_if *iface, struct net_pkt *pkt)
+{
+	net_if_try_queue_tx(iface, pkt, K_FOREVER);
+}
+
+void net_if_try_queue_tx(struct net_if *iface, struct net_pkt *pkt, k_timeout timeout)
 {
 	if (!net_pkt_filter_send_ok(pkt)) {
 		/* silently drop the packet */
@@ -368,7 +373,7 @@ void net_if_queue_tx(struct net_if *iface, struct net_pkt *pkt)
 
 		net_if_tx(net_pkt_iface(pkt), pkt);
 	} else {
-		if (net_tc_submit_to_tx_queue(tc, pkt) != NET_OK) {
+		if (net_tc_try_submit_to_tx_queue(tc, pkt, timeout) != NET_OK) {
 			goto drop;
 		}
 #if defined(CONFIG_NET_POWER_MANAGEMENT)
@@ -451,7 +456,12 @@ static inline void init_iface(struct net_if *iface)
 }
 
 #if defined(CONFIG_NET_NATIVE)
-enum net_verdict net_if_send_data(struct net_if *iface, struct net_pkt *pkt)
+enum net_verdict net_if_send_data(struct net_if *iface, struct net_pkt *pkt, k_timeout timeout)
+{
+	return net_if_try_send_data(iface, pkt, K_FOREVER);
+}
+
+enum net_verdict net_if_try_send_data(struct net_if *iface, struct net_pkt *pkt, k_timeout timeout)
 {
 	const struct net_l2 *l2;
 	struct net_context *context = net_pkt_context(pkt);
@@ -550,7 +560,7 @@ enum net_verdict net_if_send_data(struct net_if *iface, struct net_pkt *pkt)
 		}
 	} else if (verdict == NET_OK) {
 		/* Packet is ready to be sent by L2, let's queue */
-		net_if_queue_tx(iface, pkt);
+		net_if_try_queue_tx(iface, pkt, timeout);
 	}
 
 	return verdict;
diff --git a/subsys/net/ip/net_private.h b/subsys/net/ip/net_private.h
index ee71d2bb75ec..36e473e0a503 100644
--- a/subsys/net/ip/net_private.h
+++ b/subsys/net/ip/net_private.h
@@ -203,7 +203,7 @@ static inline enum net_verdict net_ipv6_input(struct net_pkt *pkt,
 static inline void net_tc_tx_init(void) { }
 static inline void net_tc_rx_init(void) { }
 #endif
-extern enum net_verdict net_tc_submit_to_tx_queue(uint8_t tc, struct net_pkt *pkt);
+enum net_verdict net_tc_try_submit_to_tx_queue(uint8_t tc, struct net_pkt *pkt, k_timeout timeout);
 extern enum net_verdict net_tc_submit_to_rx_queue(uint8_t tc, struct net_pkt *pkt);
 extern enum net_verdict net_promisc_mode_input(struct net_pkt *pkt);
 
diff --git a/subsys/net/ip/net_tc.c b/subsys/net/ip/net_tc.c
index 8846ab15cc8c..ac8aea055411 100644
--- a/subsys/net/ip/net_tc.c
+++ b/subsys/net/ip/net_tc.c
@@ -65,13 +65,13 @@ static struct net_traffic_class tx_classes[NET_TC_TX_COUNT];
 static struct net_traffic_class rx_classes[NET_TC_RX_COUNT];
 #endif
 
-enum net_verdict net_tc_submit_to_tx_queue(uint8_t tc, struct net_pkt *pkt)
+enum net_verdict net_tc_try_submit_to_tx_queue(uint8_t tc, struct net_pkt *pkt, k_timeout timeout)
 {
 #if NET_TC_TX_COUNT > 0
 	net_pkt_set_tx_stats_tick(pkt, k_cycle_get_32());
 
 #if NET_TC_TX_EFFECTIVE_COUNT > 1
-	if (k_sem_take(&tx_classes[tc].fifo_slot, K_FOREVER) != 0) {
+	if (k_sem_take(&tx_classes[tc].fifo_slot, timeout) != 0) {
 		return NET_DROP;
 	}
 #endif
diff --git a/subsys/net/l2/ethernet/arp.c b/subsys/net/l2/ethernet/arp.c
index 964dd9e3eda9..79a230b8d107 100644
--- a/subsys/net/l2/ethernet/arp.c
+++ b/subsys/net/l2/ethernet/arp.c
@@ -531,7 +531,9 @@ static void arp_gratuitous_send(struct net_if *iface,
 
 	NET_DBG("Sending gratuitous ARP pkt %p", pkt);
 
-	if (net_if_send_data(iface, pkt) == NET_DROP) {
+	/* send without timeout, so we do not risk being blocked by tx when
+	 * being flooded */
+	if (net_if_try_send_data(iface, pkt, K_NO_WAIT) == NET_DROP) {
 		net_pkt_unref(pkt);
 	}
 }
@@ -874,7 +876,7 @@ enum net_verdict net_arp_input(struct net_pkt *pkt,
 		/* Send reply */
 		reply = arp_prepare_reply(net_pkt_iface(pkt), pkt, dst_hw_addr);
 		if (reply) {
-			net_if_queue_tx(net_pkt_iface(reply), reply);
+			net_if_try_queue_tx(net_pkt_iface(reply), reply, K_NO_WAIT);
 		} else {
 			NET_DBG("Cannot send ARP reply");
 		}
diff --git a/subsys/net/l2/ethernet/bridge.c b/subsys/net/l2/ethernet/bridge.c
index 4b883643c3a3..4e43117b6746 100644
--- a/subsys/net/l2/ethernet/bridge.c
+++ b/subsys/net/l2/ethernet/bridge.c
@@ -384,7 +384,7 @@ static enum net_verdict bridge_iface_process(struct net_if *iface,
 
 			net_pkt_set_family(send_pkt, AF_UNSPEC);
 			net_pkt_set_iface(send_pkt, ctx->eth_iface[i]);
-			net_if_queue_tx(ctx->eth_iface[i], send_pkt);
+			net_if_try_queue_tx(ctx->eth_iface[i], send_pkt, K_FOREVER);
 
 			NET_DBG("%s iface %d pkt %p (ref %d)",
 				is_send ? "Send" : "Recv",
diff --git a/subsys/net/l2/ethernet/ethernet.c b/subsys/net/l2/ethernet/ethernet.c
index 88f3bc824b9e..97f68d4d0c6c 100644
--- a/subsys/net/l2/ethernet/ethernet.c
+++ b/subsys/net/l2/ethernet/ethernet.c
@@ -281,7 +281,7 @@ static enum net_verdict ethernet_recv(struct net_if *iface,
 			out_pkt, pkt, net_if_get_by_iface(bridge),
 			net_if_get_by_iface(iface));
 
-		(void)net_if_queue_tx(bridge, out_pkt);
+		(void)net_if_try_queue_tx(bridge, out_pkt, K_FOREVER);
 	}
 
 	type = ntohs(hdr->type);
@@ -788,7 +788,7 @@ static int ethernet_send(struct net_if *iface, struct net_pkt *pkt)
 			out_pkt, pkt, net_if_get_by_iface(bridge),
 			net_if_get_by_iface(iface));
 
-		(void)net_if_queue_tx(bridge, out_pkt);
+		(void)net_if_try_queue_tx(bridge, out_pkt, K_FOREVER);
 	}
 
 	ret = net_l2_send(api->send, net_if_get_device(iface), iface, pkt);
diff --git a/subsys/net/l2/ethernet/gptp/gptp_messages.c b/subsys/net/l2/ethernet/gptp/gptp_messages.c
index 7fc5c75b73fd..1bfac947a48f 100644
--- a/subsys/net/l2/ethernet/gptp/gptp_messages.c
+++ b/subsys/net/l2/ethernet/gptp/gptp_messages.c
@@ -826,7 +826,7 @@ void gptp_send_sync(int port, struct net_pkt *pkt)
 
 	NET_GPTP_INFO("SYNC", pkt);
 
-	net_if_queue_tx(net_pkt_iface(pkt), pkt);
+	net_if_try_queue_tx(net_pkt_iface(pkt), pkt, K_FOREVER);
 }
 
 void gptp_send_follow_up(int port, struct net_pkt *pkt)
@@ -835,7 +835,7 @@ void gptp_send_follow_up(int port, struct net_pkt *pkt)
 
 	NET_GPTP_INFO("FOLLOWUP", pkt);
 
-	net_if_queue_tx(net_pkt_iface(pkt), pkt);
+	net_if_try_queue_tx(net_pkt_iface(pkt), pkt, K_FOREVER);
 }
 
 void gptp_send_announce(int port, struct net_pkt *pkt)
@@ -844,7 +844,7 @@ void gptp_send_announce(int port, struct net_pkt *pkt)
 
 	NET_GPTP_INFO("ANNOUNCE", pkt);
 
-	net_if_queue_tx(net_pkt_iface(pkt), pkt);
+	net_if_try_queue_tx(net_pkt_iface(pkt), pkt, K_FOREVER);
 }
 
 void gptp_send_pdelay_req(int port)
@@ -871,7 +871,7 @@ void gptp_send_pdelay_req(int port)
 
 		NET_GPTP_INFO("PDELAY_REQ", pkt);
 
-		net_if_queue_tx(net_pkt_iface(pkt), pkt);
+		net_if_try_queue_tx(net_pkt_iface(pkt), pkt, K_FOREVER);
 	} else {
 		NET_ERR("Failed to prepare %s", "PDELAY_REQ");
 	}
@@ -897,7 +897,7 @@ void gptp_send_pdelay_resp(int port, struct net_pkt *pkt,
 
 	NET_GPTP_INFO("PDELAY_RESP", pkt);
 
-	net_if_queue_tx(net_pkt_iface(pkt), pkt);
+	net_if_try_queue_tx(net_pkt_iface(pkt), pkt, K_FOREVER);
 }
 
 void gptp_send_pdelay_follow_up(int port, struct net_pkt *pkt,
@@ -920,5 +920,5 @@ void gptp_send_pdelay_follow_up(int port, struct net_pkt *pkt,
 
 	NET_GPTP_INFO("PDELAY_FOLLOWUP", pkt);
 
-	net_if_queue_tx(net_pkt_iface(pkt), pkt);
+	net_if_try_queue_tx(net_pkt_iface(pkt), pkt, K_FOREVER);
 }
diff --git a/subsys/net/l2/ethernet/lldp/lldp.c b/subsys/net/l2/ethernet/lldp/lldp.c
index da179f728236..17ad6ba8b0ae 100644
--- a/subsys/net/l2/ethernet/lldp/lldp.c
+++ b/subsys/net/l2/ethernet/lldp/lldp.c
@@ -147,7 +147,9 @@ static int lldp_send(struct ethernet_lldp *lldp)
 	net_pkt_lladdr_dst(pkt)->addr = (uint8_t *)lldp_multicast_eth_addr.addr;
 	net_pkt_lladdr_dst(pkt)->len = sizeof(struct net_eth_addr);
 
-	if (net_if_send_data(lldp->iface, pkt) == NET_DROP) {
+	/* send without timeout, so we do not risk being blocked by tx when
+	 * being flooded */
+	if (net_if_try_send_data(lldp->iface, pkt, K_NO_WAIT) == NET_DROP) {
 		net_pkt_unref(pkt);
 		ret = -EIO;
 	}
diff --git a/subsys/net/lib/capture/capture.c b/subsys/net/lib/capture/capture.c
index 122096c96fcb..eaf70f2a7c51 100644
--- a/subsys/net/lib/capture/capture.c
+++ b/subsys/net/lib/capture/capture.c
@@ -707,7 +707,7 @@ static int capture_send(const struct device *dev, struct net_if *iface,
 
 	net_pkt_cursor_init(pkt);
 
-	verdict = net_if_send_data(ctx->tunnel_iface, pkt);
+	verdict = net_if_try_send_data(ctx->tunnel_iface, pkt, K_FOREVER);
 	if (verdict == NET_DROP) {
 		ret = -EIO;
 	}