network: add UDP wrapper

Tested with NTPClient and ArduinoMDNS

TODO: properly test multicast

Author: facchinm

Diff for: libraries/SocketWrapper/ZephyrUDP.h

@@ -0,0 +1,330 @@
+/*
+  MbedUdp.h - UDP implementation using mbed Sockets
+  Copyright (c) 2021 Arduino SA.  All right reserved.
+
+  This library is free software; you can redistribute it and/or
+  modify it under the terms of the GNU Lesser General Public
+  License as published by the Free Software Foundation; either
+  version 2.1 of the License, or (at your option) any later version.
+
+  This library 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
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public
+  License along with this library; if not, write to the Free Software
+  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include "Arduino.h"
+#include "SocketWrapper.h"
+#include "api/Udp.h"
+#include "sys/socket.h"
+#include "zephyr/net/net_ip.h"
+#include "zephyr/net/net_if.h"
+
+#include <list>
+#include <deque>
+#include <vector>
+#include <memory>
+
+class ZephyrUDP : public arduino::UDP {
+private:
+  int _socket;
+
+public:
+  ZephyrUDP() : _socket(-1) {}  // Constructor
+  ~ZephyrUDP() {
+    stop();
+  }
+
+  // initialize, start listening on specified port. Returns 1 if successful, 0 if there are no sockets available to use
+  virtual uint8_t begin(uint16_t port) {
+
+    struct sockaddr_in addr;
+    addr.sin_family = AF_INET;
+    addr.sin_port = htons(port);
+    addr.sin_addr.s_addr = INADDR_ANY;
+
+    _socket = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
+
+    zsock_ioctl(_socket, ZFD_IOCTL_FIONBIO);
+
+    if (::bind(_socket, (struct sockaddr*)&addr, sizeof(addr)) < 0) {
+        ::close(_socket);
+        _socket = -1;
+        return false;
+    }
+
+    return true;
+  }
+
+  // initialize, start listening on specified multicast IP address and port. Returns 1 if successful, 0 if there are no sockets available to use
+  virtual uint8_t beginMulticast(IPAddress ip, uint16_t port) {
+    bool ret = begin(port);
+    if (ret == false) {
+      return false;
+    }
+
+    struct sockaddr_in addr;
+    addr.sin_family = AF_INET;
+    addr.sin_addr.s_addr = ip;
+
+    net_if_ipv4_maddr_join(net_if_get_by_index(1), net_if_ipv4_maddr_add(net_if_get_by_index(1), (struct in_addr*)&addr));
+    return true;
+  }
+
+  // Finish with the UDP socket
+  virtual void stop() {
+    if (_socket != -1) {
+      ::close(_socket);
+      _socket = -1;
+    }
+  }
+
+  // Sending UDP packets
+
+  // Start building up a packet to send to the remote host specific in ip and port
+  // Returns 1 if successful, 0 if there was a problem with the supplied IP address or port
+  virtual int beginPacket(IPAddress ip, uint16_t port) {
+    _send_to_ip = ip;
+    _send_to_port = port;
+
+    /* Make sure that the transmit data buffer is empty. */
+    _tx_data.clear();
+    return true;
+  }
+
+  // Start building up a packet to send to the remote host specific in host and port
+  // Returns 1 if successful, 0 if there was a problem resolving the hostname or port
+  virtual int beginPacket(const char* host, uint16_t port) {
+    // Resolve address
+    struct addrinfo hints;
+	  struct addrinfo *res;
+
+    hints.ai_family = AF_INET;
+    hints.ai_socktype = SOCK_DGRAM;
+
+    int resolve_attempts = 100;
+    int ret;
+
+    while (resolve_attempts--) {
+      ret = getaddrinfo(host, String(port).c_str(), &hints, &res);
+
+      if (ret == 0) {
+        break;
+      } else {
+        k_sleep(K_MSEC(1));
+      }
+    }
+
+    if (ret != 0) {
+      return false;
+    }
+
+    return beginPacket(IPAddress(((sockaddr_in*)(res->ai_addr))->sin_addr.s_addr), port);
+  }
+  
+  // Finish off this packet and send it
+  // Returns 1 if the packet was sent successfully, 0 if there was an error
+  virtual int endPacket() {
+    struct sockaddr_in addr;
+    addr.sin_family = AF_INET;
+    addr.sin_port = htons(_send_to_port);
+    addr.sin_addr.s_addr = _send_to_ip;
+    return ::sendto(_socket, _tx_data.data(), _tx_data.size(), 0, (sockaddr*)&addr, sizeof(addr));
+  }
+
+  // Write a single byte into the packet
+  virtual size_t write(uint8_t data) {
+    _tx_data.push_back(data);
+    return 1;
+  }
+
+  // Write size bytes from buffer into the packet
+  virtual size_t write(uint8_t* buffer, size_t size) {
+    std::copy(buffer, buffer + size, std::back_inserter(_tx_data));
+    return size;
+  }
+
+  // Write size bytes from buffer into the packet
+  virtual size_t write(const uint8_t* buffer, size_t size) {
+    std::copy(buffer, buffer + size, std::back_inserter(_tx_data));
+    return size;
+  }
+
+  using Print::write;
+
+  int parsePacket()
+  {
+    struct sockaddr_in addr;
+    socklen_t addrlen = sizeof(addr);
+    uint8_t tmp_buf[512];
+
+    int ret = ::recvfrom(_socket, tmp_buf, sizeof(tmp_buf), 0, (sockaddr*)&addr, &addrlen);
+    if (ret > 0)
+    {
+      auto pkt = std::make_shared<UdpRxPacket>(
+          IPAddress(addr.sin_addr.s_addr),
+          ntohs(addr.sin_port), tmp_buf, ret);
+
+      _rx_pkt_list.push_back(pkt);
+
+      // drop the oldest packet if the list is full
+      if(_rx_pkt_list.size() > _rx_pkt_list_size) {
+          _rx_pkt_list.pop_front();
+      }
+    }
+
+    if (_rx_pkt_list.size())
+    {
+      /* Discard UdpRxPacket object previously held by _rx_pkt
+      * and replace it with the new one.
+      */
+      _rx_pkt = _rx_pkt_list.front();
+      _rx_pkt_list.pop_front();
+      return _rx_pkt->totalSize();
+    }
+    else
+    {
+      /* Otherwise ensure that _rx_pkt definitely
+      * does not hold any UdpRxPacket object anymore.
+      */
+      _rx_pkt.reset();
+      return 0;
+    }
+  }
+
+  int available()
+  {
+    if (_rx_pkt)
+      return _rx_pkt->available();
+    else
+      return 0;
+  }
+
+  int read()
+  {
+    if (_rx_pkt)
+    return _rx_pkt->read();
+    else
+      return -1;
+  }
+
+  int read(unsigned char* buffer, size_t len)
+  {
+    if (_rx_pkt)
+      return _rx_pkt->read(buffer, len);
+    else
+      return -1;
+  }
+
+  int read(char* buffer, size_t len)
+  {
+    if (_rx_pkt)
+      return _rx_pkt->read(buffer, len);
+    else
+      return -1;
+  }
+
+  int peek()
+  {
+    if (_rx_pkt)
+      return _rx_pkt->peek();
+    else
+      return -1;
+  }
+
+  void flush()
+  {
+    /* Delete UdpRxPacket object held by _rx_pkt. */
+    if (_rx_pkt)
+      _rx_pkt.reset();
+  }
+
+  virtual IPAddress remoteIP() {
+    if (_rx_pkt)
+      return _rx_pkt->remoteIP();
+    else
+      return IPAddress();
+  }
+
+  virtual uint16_t remotePort() {
+    if (_rx_pkt)
+      return _rx_pkt->remotePort();
+    else
+      return 0;
+  }
+
+private:
+
+  /* UDP TRANSMISSION */
+  IPAddress _send_to_ip;
+  uint16_t _send_to_port;
+  std::vector<uint8_t> _tx_data;
+  int _rx_pkt_list_size = 10;
+  /* UDP RECEPTION */
+  class UdpRxPacket
+  {
+  private:
+    IPAddress const _remote_ip;
+    uint16_t const _remote_port;
+    size_t const _rx_data_len;
+    std::deque<uint8_t> _rx_data;
+
+  public:
+    UdpRxPacket(
+      IPAddress const remote_ip,
+      uint16_t const remote_port,
+      uint8_t const * p_data,
+      size_t const data_len)
+      : _remote_ip(remote_ip)
+      , _remote_port(remote_port)
+      , _rx_data_len(data_len)
+      , _rx_data(p_data, p_data + data_len)
+    {
+    }
+
+    typedef std::shared_ptr<UdpRxPacket> SharedPtr;
+
+    IPAddress remoteIP() const { return _remote_ip; }
+    uint16_t remotePort() const { return _remote_port; }
+    size_t totalSize() const { return _rx_data_len; }
+
+    int available()
+    {
+      return _rx_data.size();
+    }
+
+    int read()
+    {
+      uint8_t const data = _rx_data.front();
+      _rx_data.pop_front();
+      return data;
+    }
+
+    int read(unsigned char* buffer, size_t len)
+    {
+      size_t bytes_read = 0;
+      for (; bytes_read < len && !_rx_data.empty(); bytes_read++)
+      {
+        buffer[bytes_read] = _rx_data.front();
+        _rx_data.pop_front();
+      }
+      return bytes_read;
+    }
+
+    int read(char* buffer, size_t len)
+    {
+      return read((unsigned char*)buffer, len);
+    }
+
+    int peek()
+    {
+      return _rx_data.front();
+    }
+  };
+  std::list<UdpRxPacket::SharedPtr> _rx_pkt_list;
+  UdpRxPacket::SharedPtr _rx_pkt;
+};

Diff for: loader/llext_exports.c

@@ -21,8 +21,10 @@ EXPORT_SYMBOL(strtoul);
 EXPORT_SYMBOL(strcmp);
 EXPORT_SYMBOL(strlen);
 EXPORT_SYMBOL(strchr);
+EXPORT_SYMBOL(strcat);
 EXPORT_SYMBOL(memmove);
 
+EXPORT_SYMBOL(k_malloc);
 EXPORT_SYMBOL(malloc);
 EXPORT_SYMBOL(realloc);
 EXPORT_SYMBOL(calloc);
@@ -54,6 +56,8 @@ EXPORT_SYMBOL(z_log_msg_runtime_vcreate);
 #if defined(CONFIG_NETWORKING)
 FORCE_EXPORT_SYM(net_if_foreach);
 FORCE_EXPORT_SYM(net_if_get_by_iface);
+FORCE_EXPORT_SYM(net_if_ipv4_maddr_add);
+FORCE_EXPORT_SYM(net_if_ipv4_maddr_join);
 #endif
 
 #if defined(CONFIG_NET_DHCPV4)
@@ -64,14 +68,14 @@ FORCE_EXPORT_SYM(net_dhcpv4_add_option_callback);
 #endif
 
 #if defined(CONFIG_NET_MGMT_EVENT)
-FORCE_EXPORT_SYM(net_mgmt_NET_REQUEST_WIFI_CONNECT);
-FORCE_EXPORT_SYM(net_mgmt_NET_REQUEST_WIFI_IFACE_STATUS);
 FORCE_EXPORT_SYM(net_mgmt_add_event_callback);
 FORCE_EXPORT_SYM(net_mgmt_event_wait_on_iface);
 #endif
 
 #if defined(CONFIG_WIFI)
 FORCE_EXPORT_SYM(net_if_get_wifi_sta);
+FORCE_EXPORT_SYM(net_mgmt_NET_REQUEST_WIFI_CONNECT);
+FORCE_EXPORT_SYM(net_mgmt_NET_REQUEST_WIFI_IFACE_STATUS);
 #endif
 
 #if defined(CONFIG_BT)
@@ -105,6 +109,8 @@ FORCE_EXPORT_SYM(bind);
 FORCE_EXPORT_SYM(listen);
 EXPORT_SYMBOL(exit);
 FORCE_EXPORT_SYM(inet_pton);
+FORCE_EXPORT_SYM(sendto);
+FORCE_EXPORT_SYM(recvfrom);
 #endif
 
 #if defined(CONFIG_CDC_ACM_DTE_RATE_CALLBACK_SUPPORT)