[PATCH] net: add a generic udp protocol

[Philippe Reynes]

This commit adds a generic udp protocol framework in the
network loop. So protocol based on udp may be implemented
without modifying the network loop (for example custom
wait magic packet).

Signed-off-by: Philippe Reynes <philippe.reynes at softathome.com>
---
 include/net.h     |  2 +-
 include/net/udp.h | 31 +++++++++++++++++++++++++++++++
 net/Kconfig       |  6 ++++++
 net/Makefile      |  1 +
 net/net.c         | 15 ++++++++++++++-
 net/udp.c         | 48 ++++++++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 101 insertions(+), 2 deletions(-)
 create mode 100644 include/net/udp.h
 create mode 100644 net/udp.c

diff --git a/include/net.h b/include/net.h
index 1bf9867..2191071 100644
--- a/include/net.h
+++ b/include/net.h
@@ -551,7 +551,7 @@ extern int		net_restart_wrap;	/* Tried all network devices */
 
 enum proto_t {
 	BOOTP, RARP, ARP, TFTPGET, DHCP, PING, DNS, NFS, CDP, NETCONS, SNTP,
-	TFTPSRV, TFTPPUT, LINKLOCAL, FASTBOOT, WOL
+	TFTPSRV, TFTPPUT, LINKLOCAL, FASTBOOT, WOL, UDP
 };
 
 extern char	net_boot_file_name[1024];/* Boot File name */
diff --git a/include/net/udp.h b/include/net/udp.h
new file mode 100644
index 0000000..f97df8d
--- /dev/null
+++ b/include/net/udp.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2020 Philippe Reynes <philippe.reynes at softathome.com>
+ */
+
+#ifndef __UDP
+#define __UDP
+
+/**
+ * struct udp_ops - function to handle udp packet
+ *
+ * This structure provides the function to handle udp packet in
+ * the network loop.
+ *
+ * @prereq: callback called to check the requirement
+ * @start: callback called to start the protocol/feature
+ * @data: pointer to store private data (used by prereq and start)
+ */
+struct udp_ops {
+	int (*prereq)(void *data);
+	int (*start)(void *data);
+	void *data;
+};
+
+int udp_prereq(void);
+
+int udp_start(void);
+
+int udp_loop(struct udp_ops *h);
+
+#endif
diff --git a/net/Kconfig b/net/Kconfig
index 6874b55..db8d796 100644
--- a/net/Kconfig
+++ b/net/Kconfig
@@ -8,6 +8,12 @@ menuconfig NET
 
 if NET
 
+config PROT_UDP
+	bool "Enable generic udp framework"
+	help
+	  Enable a generic udp framework that allow to define custom
+	  handler for udp protocol.
+
 config BOOTP_SEND_HOSTNAME
 	bool "Send hostname to DNS server"
 	help
diff --git a/net/Makefile b/net/Makefile
index fef71b9..76527f7 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -27,6 +27,7 @@ obj-$(CONFIG_CMD_SNTP) += sntp.o
 obj-$(CONFIG_CMD_TFTPBOOT) += tftp.o
 obj-$(CONFIG_UDP_FUNCTION_FASTBOOT)  += fastboot.o
 obj-$(CONFIG_CMD_WOL)  += wol.o
+obj-$(CONFIG_PROT_UDP) += udp.o
 
 # Disable this warning as it is triggered by:
 # sprintf(buf, index ? "foo%d" : "foo", index)
diff --git a/net/net.c b/net/net.c
index 28d9eeb..f6ae814 100644
--- a/net/net.c
+++ b/net/net.c
@@ -102,6 +102,7 @@
 #if defined(CONFIG_CMD_PCAP)
 #include <net/pcap.h>
 #endif
+#include <net/udp.h>
 #if defined(CONFIG_LED_STATUS)
 #include <miiphy.h>
 #include <status_led.h>
@@ -540,6 +541,11 @@ restart:
 			wol_start();
 			break;
 #endif
+#if defined(CONFIG_PROT_UDP)
+		case UDP:
+			udp_start();
+			break;
+#endif
 		default:
 			break;
 		}
@@ -1364,6 +1370,13 @@ static int net_check_prereq(enum proto_t protocol)
 		}
 		goto common;
 #endif
+#if defined(CONFIG_PROT_UDP)
+	case UDP:
+		if (udp_prereq())
+			return 1;
+		goto common;
+#endif
+
 #if defined(CONFIG_CMD_NFS)
 	case NFS:
 #endif
@@ -1375,7 +1388,7 @@ static int net_check_prereq(enum proto_t protocol)
 			return 1;
 		}
 #if	defined(CONFIG_CMD_PING) || defined(CONFIG_CMD_SNTP) || \
-	defined(CONFIG_CMD_DNS)
+	defined(CONFIG_CMD_DNS) || defined(CONFIG_PROT_UDP)
 common:
 #endif
 		/* Fall through */
diff --git a/net/udp.c b/net/udp.c
new file mode 100644
index 0000000..2409ce4
--- /dev/null
+++ b/net/udp.c
@@ -0,0 +1,48 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2020 Philippe Reynes <philippe.reynes at softathome.com>
+ */
+
+#include <common.h>
+#include <net.h>
+#include <net/udp.h>
+
+static struct udp_ops *udp_ops;
+
+int udp_prereq(void)
+{
+	int ret = 0;
+
+	if (udp_ops && udp_ops->prereq)
+		ret = udp_ops->prereq(udp_ops->data);
+
+	return ret;
+}
+
+int udp_start(void)
+{
+	int ret = -1;
+
+	if (udp_ops && udp_ops->start)
+		ret = udp_ops->start(udp_ops->data);
+	else
+		printf("%s: no start function defined\n", __func__);
+
+	return ret;
+}
+
+int udp_loop(struct udp_ops *ops)
+{
+	int ret = -1;
+
+	if (!ops) {
+		printf("%s: ops should not be null\n", __func__);
+		goto out;
+	}
+
+	udp_ops = ops;
+	ret = net_loop(UDP);
+
+ out:
+	return ret;
+}
-- 
2.7.4