Initial basic TCP server

Based on the Pi example

CMakeLists.txt

@@ -0,0 +1,24 @@
+cmake_minimum_required(VERSION 3.13)
+
+include(pico_sdk_import.cmake)
+
+project(picowota C CXX ASM)
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_CXX_STANDARD 17)
+pico_sdk_init()
+
+add_executable(picowota
+	main.c
+	creds.c
+)
+
+pico_enable_stdio_usb(picowota 1)
+
+pico_add_extra_outputs(picowota)
+
+target_include_directories(picowota PRIVATE ${CMAKE_CURRENT_LIST_DIR})
+
+target_link_libraries(picowota
+	pico_cyw43_arch_lwip_threadsafe_background
+	pico_stdlib
+)

lwipopts.h

@@ -0,0 +1,90 @@
+#ifndef _LWIPOPTS_EXAMPLE_COMMONH_H
+#define _LWIPOPTS_EXAMPLE_COMMONH_H
+
+
+// Common settings used in most of the pico_w examples
+// (see https://www.nongnu.org/lwip/2_1_x/group__lwip__opts.html for details)
+
+// allow override in some examples
+#ifndef NO_SYS
+#define NO_SYS                      1
+#endif
+// allow override in some examples
+#ifndef LWIP_SOCKET
+#define LWIP_SOCKET                 0
+#endif
+#if PICO_CYW43_ARCH_POLL
+#define MEM_LIBC_MALLOC             1
+#else
+// MEM_LIBC_MALLOC is incompatible with non polling versions
+#define MEM_LIBC_MALLOC             0
+#endif
+#define MEM_ALIGNMENT               4
+#define MEM_SIZE                    4000
+#define MEMP_NUM_TCP_SEG            32
+#define MEMP_NUM_ARP_QUEUE          10
+#define PBUF_POOL_SIZE              24
+#define LWIP_ARP                    1
+#define LWIP_ETHERNET               1
+#define LWIP_ICMP                   1
+#define LWIP_RAW                    1
+#define TCP_WND                     (8 * TCP_MSS)
+#define TCP_MSS                     1460
+#define TCP_SND_BUF                 (8 * TCP_MSS)
+#define TCP_SND_QUEUELEN            ((4 * (TCP_SND_BUF) + (TCP_MSS - 1)) / (TCP_MSS))
+#define LWIP_NETIF_STATUS_CALLBACK  1
+#define LWIP_NETIF_LINK_CALLBACK    1
+#define LWIP_NETIF_HOSTNAME         1
+#define LWIP_NETCONN                0
+#define MEM_STATS                   0
+#define SYS_STATS                   0
+#define MEMP_STATS                  0
+#define LINK_STATS                  0
+// #define ETH_PAD_SIZE                2
+#define LWIP_CHKSUM_ALGORITHM       3
+#define LWIP_DHCP                   1
+#define LWIP_IPV4                   1
+#define LWIP_TCP                    1
+#define LWIP_UDP                    1
+#define LWIP_DNS                    1
+#define LWIP_TCP_KEEPALIVE          1
+#define LWIP_NETIF_TX_SINGLE_PBUF   1
+#define DHCP_DOES_ARP_CHECK         0
+#define LWIP_DHCP_DOES_ACD_CHECK    0
+
+#ifndef NDEBUG
+#define LWIP_DEBUG                  1
+#define LWIP_STATS                  1
+#define LWIP_STATS_DISPLAY          1
+#endif
+
+#define ETHARP_DEBUG                LWIP_DBG_OFF
+#define NETIF_DEBUG                 LWIP_DBG_OFF
+#define PBUF_DEBUG                  LWIP_DBG_OFF
+#define API_LIB_DEBUG               LWIP_DBG_OFF
+#define API_MSG_DEBUG               LWIP_DBG_OFF
+#define SOCKETS_DEBUG               LWIP_DBG_OFF
+#define ICMP_DEBUG                  LWIP_DBG_OFF
+#define INET_DEBUG                  LWIP_DBG_OFF
+#define IP_DEBUG                    LWIP_DBG_OFF
+#define IP_REASS_DEBUG              LWIP_DBG_OFF
+#define RAW_DEBUG                   LWIP_DBG_OFF
+#define MEM_DEBUG                   LWIP_DBG_OFF
+#define MEMP_DEBUG                  LWIP_DBG_OFF
+#define SYS_DEBUG                   LWIP_DBG_OFF
+#define TCP_DEBUG                   LWIP_DBG_OFF
+#define TCP_INPUT_DEBUG             LWIP_DBG_OFF
+#define TCP_OUTPUT_DEBUG            LWIP_DBG_OFF
+#define TCP_RTO_DEBUG               LWIP_DBG_OFF
+#define TCP_CWND_DEBUG              LWIP_DBG_OFF
+#define TCP_WND_DEBUG               LWIP_DBG_OFF
+#define TCP_FR_DEBUG                LWIP_DBG_OFF
+#define TCP_QLEN_DEBUG              LWIP_DBG_OFF
+#define TCP_RST_DEBUG               LWIP_DBG_OFF
+#define UDP_DEBUG                   LWIP_DBG_OFF
+#define TCPIP_DEBUG                 LWIP_DBG_OFF
+#define PPP_DEBUG                   LWIP_DBG_OFF
+#define SLIP_DEBUG                  LWIP_DBG_OFF
+#define DHCP_DEBUG                  LWIP_DBG_OFF
+
+#endif /* __LWIPOPTS_H__ */

main.c

@@ -0,0 +1,255 @@
+/**
+ * Copyright (c) 2022 Brian Starkey <stark3y@gmail.com>
+ *
+ * Based on the Pico W tcp_server example:
+ * Copyright (c) 2022 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <string.h>
+#include <stdlib.h>
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+
+#include "lwip/pbuf.h"
+#include "lwip/tcp.h"
+
+extern const char *wifi_ssid;
+extern const char *wifi_pass;
+
+#define TCP_PORT 4242
+#define DEBUG_printf printf
+#define BUF_SIZE 2048
+#define POLL_TIME_S 5
+
+typedef struct TCP_SERVER_T_ {
+	struct tcp_pcb *server_pcb;
+	struct tcp_pcb *client_pcb;
+	bool complete;
+	uint8_t buffer_recv[BUF_SIZE];
+	int sent_len;
+} TCP_SERVER_T;
+
+static TCP_SERVER_T* tcp_server_init(void) {
+	TCP_SERVER_T *state = calloc(1, sizeof(TCP_SERVER_T));
+	if (!state) {
+		DEBUG_printf("failed to allocate state\n");
+		return NULL;
+	}
+	return state;
+}
+
+static err_t tcp_server_close(void *arg) {
+	TCP_SERVER_T *state = (TCP_SERVER_T*)arg;
+	err_t err = ERR_OK;
+	if (state->client_pcb != NULL) {
+		tcp_arg(state->client_pcb, NULL);
+		tcp_poll(state->client_pcb, NULL, 0);
+		tcp_sent(state->client_pcb, NULL);
+		tcp_recv(state->client_pcb, NULL);
+		tcp_err(state->client_pcb, NULL);
+		err = tcp_close(state->client_pcb);
+		if (err != ERR_OK) {
+			DEBUG_printf("close failed %d, calling abort\n", err);
+			tcp_abort(state->client_pcb);
+			err = ERR_ABRT;
+		}
+		state->client_pcb = NULL;
+	}
+	if (state->server_pcb) {
+		tcp_arg(state->server_pcb, NULL);
+		tcp_close(state->server_pcb);
+		state->server_pcb = NULL;
+	}
+	return err;
+}
+
+static err_t tcp_server_result(void *arg, int status) {
+	TCP_SERVER_T *state = (TCP_SERVER_T*)arg;
+	if (status == 0) {
+		DEBUG_printf("completed normally\n");
+	} else {
+		DEBUG_printf("error %d\n", status);
+	}
+	state->complete = true;
+	return tcp_server_close(arg);
+}
+
+static err_t tcp_server_sent(void *arg, struct tcp_pcb *tpcb, u16_t len) {
+	TCP_SERVER_T *state = (TCP_SERVER_T*)arg;
+	DEBUG_printf("tcp_server_sent %u\n", len);
+	state->sent_len += len;
+
+	if (state->sent_len >= strlen("hello\n")) {
+		DEBUG_printf("Sending done\n");
+	}
+
+	return ERR_OK;
+}
+
+err_t tcp_server_send_data(void *arg, struct tcp_pcb *tpcb)
+{
+	TCP_SERVER_T *state = (TCP_SERVER_T*)arg;
+
+	state->sent_len = 0;
+	DEBUG_printf("Writing to client\n");
+	// this method is callback from lwIP, so cyw43_arch_lwip_begin is not required, however you
+	// can use this method to cause an assertion in debug mode, if this method is called when
+	// cyw43_arch_lwip_begin IS needed
+	cyw43_arch_lwip_check();
+	err_t err = tcp_write(tpcb, "hello\n", strlen("hello\n"), TCP_WRITE_FLAG_COPY);
+	if (err != ERR_OK) {
+		DEBUG_printf("Failed to write data %d\n", err);
+		return tcp_server_result(arg, -1);
+	}
+	return ERR_OK;
+}
+
+err_t tcp_server_recv(void *arg, struct tcp_pcb *tpcb, struct pbuf *p, err_t err) {
+	TCP_SERVER_T *state = (TCP_SERVER_T*)arg;
+	if (!p) {
+		return tcp_server_result(arg, 0);
+	}
+	// this method is callback from lwIP, so cyw43_arch_lwip_begin is not required, however you
+	// can use this method to cause an assertion in debug mode, if this method is called when
+	// cyw43_arch_lwip_begin IS needed
+	cyw43_arch_lwip_check();
+	if (p->tot_len > 0) {
+		DEBUG_printf("tcp_server_recv %d err %d\n", p->tot_len, err);
+
+		// Receive the buffer
+		pbuf_copy_partial(p, state->buffer_recv, p->tot_len, 0);
+
+		state->buffer_recv[p->tot_len] = '\0';
+		printf("%s\n", state->buffer_recv);
+		tcp_recved(tpcb, p->tot_len);
+	}
+	pbuf_free(p);
+
+	return ERR_OK;
+}
+
+static err_t tcp_server_poll(void *arg, struct tcp_pcb *tpcb) {
+	DEBUG_printf("tcp_server_poll_fn\n");
+	return ERR_OK;
+}
+
+static void tcp_server_err(void *arg, err_t err) {
+	if (err != ERR_ABRT) {
+		DEBUG_printf("tcp_client_err_fn %d\n", err);
+		tcp_server_result(arg, err);
+	} else {
+		DEBUG_printf("tcp_client_err_fn abort %d\n", err);
+		tcp_server_result(arg, err);
+	}
+}
+
+static err_t tcp_server_accept(void *arg, struct tcp_pcb *client_pcb, err_t err) {
+	TCP_SERVER_T *state = (TCP_SERVER_T*)arg;
+	if (err != ERR_OK || client_pcb == NULL) {
+		DEBUG_printf("Failure in accept\n");
+		tcp_server_result(arg, err);
+		return ERR_VAL;
+	}
+	DEBUG_printf("Client connected\n");
+
+	state->client_pcb = client_pcb;
+	tcp_arg(client_pcb, state);
+	tcp_sent(client_pcb, tcp_server_sent);
+	tcp_recv(client_pcb, tcp_server_recv);
+	tcp_poll(client_pcb, tcp_server_poll, POLL_TIME_S * 2);
+	tcp_err(client_pcb, tcp_server_err);
+
+	return tcp_server_send_data(arg, state->client_pcb);
+}
+
+static bool tcp_server_open(void *arg) {
+	TCP_SERVER_T *state = (TCP_SERVER_T*)arg;
+	DEBUG_printf("Starting server at %s on port %u\n", ip4addr_ntoa(netif_ip4_addr(netif_list)), TCP_PORT);
+
+	struct tcp_pcb *pcb = tcp_new_ip_type(IPADDR_TYPE_ANY);
+	if (!pcb) {
+		DEBUG_printf("failed to create pcb\n");
+		return false;
+	}
+
+	err_t err = tcp_bind(pcb, NULL, TCP_PORT);
+	if (err) {
+		DEBUG_printf("failed to bind to port %d\n");
+		return false;
+	}
+
+	state->server_pcb = tcp_listen_with_backlog(pcb, 1);
+	if (!state->server_pcb) {
+		DEBUG_printf("failed to listen\n");
+		if (pcb) {
+			tcp_close(pcb);
+		}
+		return false;
+	}
+
+	tcp_arg(state->server_pcb, state);
+	tcp_accept(state->server_pcb, tcp_server_accept);
+
+	return true;
+}
+
+void run_tcp_server(void) {
+	TCP_SERVER_T *state = tcp_server_init();
+	if (!state) {
+		return;
+	}
+
+	if (!tcp_server_open(state)) {
+		tcp_server_result(state, -1);
+		return;
+	}
+
+	// Block until the connection is closed
+	while(!state->complete) {
+		// the following #ifdef is only here so this same example can be used in multiple modes;
+		// you do not need it in your code
+#if PICO_CYW43_ARCH_POLL
+		// if you are using pico_cyw43_arch_poll, then you must poll periodically from your
+		// main loop (not from a timer) to check for WiFi driver or lwIP work that needs to be done.
+		cyw43_arch_poll();
+		sleep_ms(1);
+#else
+		// if you are not using pico_cyw43_arch_poll, then WiFI driver and lwIP work
+		// is done via interrupt in the background. This sleep is just an example of some (blocking)
+		// work you might be doing.
+		sleep_ms(1000);
+#endif
+	}
+	free(state);
+}
+
+int main() {
+	stdio_init_all();
+
+	sleep_ms(1000);
+
+	if (cyw43_arch_init()) {
+		printf("failed to initialise\n");
+		return 1;
+	}
+
+	cyw43_arch_enable_sta_mode();
+
+	printf("Connecting to WiFi...\n");
+	if (cyw43_arch_wifi_connect_timeout_ms(wifi_ssid, wifi_pass, CYW43_AUTH_WPA2_AES_PSK, 30000)) {
+		printf("failed to connect.\n");
+		return 1;
+	} else {
+		printf("Connected.\n");
+	}
+
+	for ( ; ; ) {
+		run_tcp_server();
+	}
+
+	cyw43_arch_deinit();
+	return 0;
+}

pico_sdk_import.cmake

@@ -0,0 +1,73 @@
+# This is a copy of <PICO_SDK_PATH>/external/pico_sdk_import.cmake
+
+# This can be dropped into an external project to help locate this SDK
+# It should be include()ed prior to project()
+
+if (DEFINED ENV{PICO_SDK_PATH} AND (NOT PICO_SDK_PATH))
+    set(PICO_SDK_PATH $ENV{PICO_SDK_PATH})
+    message("Using PICO_SDK_PATH from environment ('${PICO_SDK_PATH}')")
+endif ()
+
+if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT} AND (NOT PICO_SDK_FETCH_FROM_GIT))
+    set(PICO_SDK_FETCH_FROM_GIT $ENV{PICO_SDK_FETCH_FROM_GIT})
+    message("Using PICO_SDK_FETCH_FROM_GIT from environment ('${PICO_SDK_FETCH_FROM_GIT}')")
+endif ()
+
+if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT_PATH} AND (NOT PICO_SDK_FETCH_FROM_GIT_PATH))
+    set(PICO_SDK_FETCH_FROM_GIT_PATH $ENV{PICO_SDK_FETCH_FROM_GIT_PATH})
+    message("Using PICO_SDK_FETCH_FROM_GIT_PATH from environment ('${PICO_SDK_FETCH_FROM_GIT_PATH}')")
+endif ()
+
+set(PICO_SDK_PATH "${PICO_SDK_PATH}" CACHE PATH "Path to the Raspberry Pi Pico SDK")
+set(PICO_SDK_FETCH_FROM_GIT "${PICO_SDK_FETCH_FROM_GIT}" CACHE BOOL "Set to ON to fetch copy of SDK from git if not otherwise locatable")
+set(PICO_SDK_FETCH_FROM_GIT_PATH "${PICO_SDK_FETCH_FROM_GIT_PATH}" CACHE FILEPATH "location to download SDK")
+
+if (NOT PICO_SDK_PATH)
+    if (PICO_SDK_FETCH_FROM_GIT)
+        include(FetchContent)
+        set(FETCHCONTENT_BASE_DIR_SAVE ${FETCHCONTENT_BASE_DIR})
+        if (PICO_SDK_FETCH_FROM_GIT_PATH)
+            get_filename_component(FETCHCONTENT_BASE_DIR "${PICO_SDK_FETCH_FROM_GIT_PATH}" REALPATH BASE_DIR "${CMAKE_SOURCE_DIR}")
+        endif ()
+        # GIT_SUBMODULES_RECURSE was added in 3.17
+        if (${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.17.0")
+            FetchContent_Declare(
+                    pico_sdk
+                    GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
+                    GIT_TAG master
+                    GIT_SUBMODULES_RECURSE FALSE
+            )
+        else ()
+            FetchContent_Declare(
+                    pico_sdk
+                    GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
+                    GIT_TAG master
+            )
+        endif ()
+
+        if (NOT pico_sdk)
+            message("Downloading Raspberry Pi Pico SDK")
+            FetchContent_Populate(pico_sdk)
+            set(PICO_SDK_PATH ${pico_sdk_SOURCE_DIR})
+        endif ()
+        set(FETCHCONTENT_BASE_DIR ${FETCHCONTENT_BASE_DIR_SAVE})
+    else ()
+        message(FATAL_ERROR
+                "SDK location was not specified. Please set PICO_SDK_PATH or set PICO_SDK_FETCH_FROM_GIT to on to fetch from git."
+                )
+    endif ()
+endif ()
+
+get_filename_component(PICO_SDK_PATH "${PICO_SDK_PATH}" REALPATH BASE_DIR "${CMAKE_BINARY_DIR}")
+if (NOT EXISTS ${PICO_SDK_PATH})
+    message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' not found")
+endif ()
+
+set(PICO_SDK_INIT_CMAKE_FILE ${PICO_SDK_PATH}/pico_sdk_init.cmake)
+if (NOT EXISTS ${PICO_SDK_INIT_CMAKE_FILE})
+    message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' does not appear to contain the Raspberry Pi Pico SDK")
+endif ()
+
+set(PICO_SDK_PATH ${PICO_SDK_PATH} CACHE PATH "Path to the Raspberry Pi Pico SDK" FORCE)
+
+include(${PICO_SDK_INIT_CMAKE_FILE})