lwIP changes for PPP service

Created (a new) PPP interface for PPP service. Removed lwip
dependencies to PPP (memory allocations etc.). Moved PPP
configuration options away from lwIP mbed_lib.json to new
PPP service. For backwards compatibility, using the old
options is also currently supported.

Author: Mika Leppänen

features/lwipstack/LWIPInterface.cpp

@@ -36,8 +36,6 @@
 #include "lwip/dns.h"
 #include "lwip/udp.h"
 
-#include "ppp_lwip.h"
-
 #include "LWIPStack.h"
 
 LWIP::Interface *LWIP::Interface::list;
@@ -352,7 +350,7 @@ char *LWIP::Interface::get_gateway(char *buf, nsapi_size_t buflen)
 LWIP::Interface::Interface() :
     hw(NULL), has_addr_state(0),
     connected(NSAPI_STATUS_DISCONNECTED),
-    dhcp_started(false), dhcp_has_to_be_set(false), blocking(true), ppp(false)
+    dhcp_started(false), dhcp_has_to_be_set(false), blocking(true), ppp_enabled(false)
 {
     memset(&netif, 0, sizeof netif);
 
@@ -395,7 +393,7 @@ nsapi_error_t LWIP::add_ethernet_interface(EMAC &emac, bool default_if, OnboardN
     }
     interface->emac = &emac;
     interface->memory_manager = &memory_manager;
-    interface->ppp = false;
+    interface->ppp_enabled = false;
 
 #if (MBED_MAC_ADDRESS_SUM != MBED_MAC_ADDR_INTERFACE)
     netif->interface.hwaddr[0] = MBED_MAC_ADDR_0;
@@ -452,7 +450,7 @@ nsapi_error_t LWIP::add_l3ip_interface(L3IP &l3ip, bool default_if, OnboardNetwo
     }
     interface->l3ip = &l3ip;
     interface->memory_manager = &memory_manager;
-    interface->ppp = false;
+    interface->ppp_enabled = false;
 
 
 
@@ -462,7 +460,7 @@ nsapi_error_t LWIP::add_l3ip_interface(L3IP &l3ip, bool default_if, OnboardNetwo
 #if LWIP_IPV4
                    0, 0, 0,
 #endif
-                   interface, &LWIP::Interface::l3ip_if_init, tcpip_input)) {
+                   interface, &LWIP::Interface::l3ip_if_init, ip_input)) {
         return NSAPI_ERROR_DEVICE_ERROR;
     }
 
@@ -521,21 +519,27 @@ nsapi_error_t LWIP::remove_l3ip_interface(OnboardNetworkStack::Interface **inter
 
 #endif //LWIP_L3IP
 }
-/* Internal API to preserve existing PPP functionality - revise to better match mbed_ipstak_add_ethernet_interface later */
-nsapi_error_t LWIP::_add_ppp_interface(void *hw, bool default_if, nsapi_ip_stack_t stack, LWIP::Interface **interface_out)
+
+
+nsapi_error_t LWIP::add_ppp_interface(PPP &ppp, bool default_if, OnboardNetworkStack::Interface **interface_out)
 {
-#if LWIP_PPP_API
+#if PPP_SUPPORT
     Interface *interface = new (std::nothrow) Interface();
     if (!interface) {
         return NSAPI_ERROR_NO_MEMORY;
     }
-    interface->hw = hw;
-    interface->ppp = true;
+    interface->ppp = &ppp;
+    interface->memory_manager = &memory_manager;
+    interface->ppp_enabled = true;
 
-    nsapi_error_t ret = ppp_lwip_if_init(hw, &interface->netif, stack);
-    if (ret != NSAPI_ERROR_OK) {
-        free(interface);
-        return ret;
+    // interface->netif.hwaddr_len = 0; should we set?
+
+    if (!netif_add(&interface->netif,
+#if LWIP_IPV4
+                   0, 0, 0,
+#endif
+                   interface, &LWIP::Interface::ppp_if_init, tcpip_input)) {
+        return NSAPI_ERROR_DEVICE_ERROR;
     }
 
     if (default_if) {
@@ -548,11 +552,62 @@ nsapi_error_t LWIP::_add_ppp_interface(void *hw, bool default_if, nsapi_ip_stack
 
     *interface_out = interface;
 
+    //lwip_add_random_seed(seed); to do?
+
+    return NSAPI_ERROR_OK;
+
+#else
+    return NSAPI_ERROR_UNSUPPORTED;
+
+#endif //PPP_SUPPORT
+}
+
+nsapi_error_t LWIP::remove_ppp_interface(OnboardNetworkStack::Interface **interface_out)
+{
+#if PPP_SUPPORT
+    if ((interface_out != NULL) && (*interface_out != NULL)) {
+
+        Interface *lwip = static_cast<Interface *>(*interface_out);
+        Interface *node = lwip->list;
+
+        if (lwip->list != NULL) {
+            if (lwip->list == lwip) {
+                // Power down PPP service
+                lwip->ppp->power_down();
+                if (netif_is_link_up(&lwip->netif)) {
+                    // Wait PPP service to report link down
+                    osSemaphoreAcquire(lwip->unlinked, osWaitForever);
+                }
+                netif_remove(&node->netif);
+                lwip->list = lwip->list->next;
+                delete node;
+            } else {
+                while (node->next != NULL && node->next != lwip) {
+                    node = node->next;
+                }
+                if (node->next != NULL && node->next == lwip) {
+                    Interface *remove = node->next;
+                    // Power down PPP service
+                    remove->ppp->power_down();
+                    if (netif_is_link_up(&lwip->netif)) {
+                        // Wait PPP service to report link down
+                        osSemaphoreAcquire(lwip->unlinked, osWaitForever);
+                    }
+                    netif_remove(&remove->netif);
+                    node->next = node->next->next;
+                    delete remove;
+                }
+            }
+        }
+    }
+
     return NSAPI_ERROR_OK;
 #else
     return NSAPI_ERROR_UNSUPPORTED;
-#endif //LWIP_PPP_API
+
+#endif //PPP_SUPPORT
 }
+
 void LWIP::set_default_interface(OnboardNetworkStack::Interface *interface)
 {
     if (interface) {
@@ -609,7 +664,7 @@ nsapi_error_t LWIP::Interface::bringup(bool dhcp, const char *ip, const char *ne
 
 #if LWIP_IPV4
     if (stack != IPV6_STACK) {
-        if (!dhcp && !ppp) {
+        if (!dhcp && !ppp_enabled) {
             ip4_addr_t ip_addr;
             ip4_addr_t netmask_addr;
             ip4_addr_t gw_addr;
@@ -629,23 +684,10 @@ nsapi_error_t LWIP::Interface::bringup(bool dhcp, const char *ip, const char *ne
         client_callback(NSAPI_EVENT_CONNECTION_STATUS_CHANGE, NSAPI_STATUS_CONNECTING);
     }
 
-    if (ppp) {
-        err_t err = ppp_lwip_connect(hw);
-        if (err) {
-            connected = NSAPI_STATUS_DISCONNECTED;
-            if (client_callback) {
-                client_callback(NSAPI_EVENT_CONNECTION_STATUS_CHANGE, NSAPI_STATUS_DISCONNECTED);
-            }
-            return err_remap(err);
-        }
-    }
 
     if (!netif_is_link_up(&netif)) {
         if (blocking) {
             if (osSemaphoreAcquire(linked, LINK_TIMEOUT * 1000) != osOK) {
-                if (ppp) {
-                    (void) ppp_lwip_disconnect(hw);
-                }
                 return NSAPI_ERROR_NO_CONNECTION;
             }
         }
@@ -665,9 +707,6 @@ nsapi_error_t LWIP::Interface::bringup(bool dhcp, const char *ip, const char *ne
     // If doesn't have address
     if (!LWIP::get_ip_addr(true, &netif)) {
         if (osSemaphoreAcquire(has_any_addr, DHCP_TIMEOUT * 1000) != osOK) {
-            if (ppp) {
-                (void) ppp_lwip_disconnect(hw);
-            }
             return NSAPI_ERROR_DHCP_FAILURE;
         }
     }
@@ -713,21 +752,7 @@ nsapi_error_t LWIP::Interface::bringdown()
     }
 #endif
 
-    if (ppp) {
-        /* this is a blocking call, returns when PPP is properly closed */
-        err_t err = ppp_lwip_disconnect(hw);
-        if (err) {
-            return err_remap(err);
-        }
-        MBED_ASSERT(!netif_is_link_up(&netif));
-        /*if (netif_is_link_up(&netif)) {
-            if (sys_arch_sem_wait(&unlinked, 15000) == SYS_ARCH_TIMEOUT) {
-                return NSAPI_ERROR_DEVICE_ERROR;
-            }
-        }*/
-    } else {
-        netif_set_down(&netif);
-    }
+    netif_set_down(&netif);
 
 #if LWIP_IPV6
     mbed_lwip_clear_ipv6_addresses(&netif);

features/lwipstack/LWIPInterfacePPP.cpp

@@ -0,0 +1,162 @@
+/*
+ * Copyright (c) 2019 ARM Limited
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "lwip/tcpip.h"
+#include "lwip/tcp.h"
+#include "lwip/ip.h"
+#include "lwip/ip_addr.h"
+#include "lwip/dns.h"
+#include "netif/etharp.h"
+#include "lwip/ethip6.h"
+#include "netsocket/nsapi_types.h"
+#include "netsocket/PPP.h"
+#include "LWIPStack.h"
+#include "lwip_tools.h"
+
+#if PPP_SUPPORT
+
+#if PPP_IPV4_SUPPORT && LWIP_IPV4
+err_t LWIP::Interface::ppp4_output(struct netif *netif, struct pbuf *p, const ip4_addr_t *ipaddr)
+{
+    /* Increase reference counter since lwip stores handle to pbuf and frees
+       it after output */
+    pbuf_ref(p);
+
+    LWIP::Interface *mbed_if = static_cast<LWIP::Interface *>(netif->state);
+    bool ret = mbed_if->ppp->link_out(p, IPV4_STACK);
+    return ret ? ERR_OK : ERR_IF;
+}
+#endif
+#if PPP_IPV6_SUPPORT && LWIP_IPV6
+err_t LWIP::Interface::ppp6_output(struct netif *netif, struct pbuf *p, const ip6_addr_t *ipaddr)
+{
+    /* Increase reference counter since lwip stores handle to pbuf and frees
+       it after output */
+    pbuf_ref(p);
+
+    LWIP::Interface *mbed_if = static_cast<LWIP::Interface *>(netif->state);
+    bool ret = mbed_if->ppp->link_out(p, IPV6_STACK);
+    return ret ? ERR_OK : ERR_IF;
+}
+#endif
+void LWIP::Interface::ppp_input(net_stack_mem_buf_t *buf)
+{
+    struct pbuf *p = static_cast<struct pbuf *>(buf);
+
+    /* pass all packets to IP stack input */
+    if (netif.input(p, &netif) != ERR_OK) {
+        LWIP_DEBUGF(NETIF_DEBUG, ("Emac LWIP: IP input error\n"));
+
+        pbuf_free(p);
+    }
+}
+
+void LWIP::Interface::ppp_state_change(bool up)
+{
+    if (up) {
+#if PPP_IPV6_SUPPORT && LWIP_IPV6
+        const nsapi_addr_t *ipv6_addr = LWIP::Interface::ppp->get_ip_address(NSAPI_IPv6);
+
+        ip_addr_t ip_addr;
+        if (ipv6_addr && convert_mbed_addr_to_lwip(&ip_addr, ipv6_addr)) {
+            netif_ip6_addr_set(&netif, 0, ip_2_ip6(&ip_addr));
+            netif_ip6_addr_set_state(&netif, 0, IP6_ADDR_PREFERRED);
+        }
+#endif
+
+#if PPP_IPV4_SUPPORT && LWIP_IPV4
+        const nsapi_addr_t *ipv4_addr = LWIP::Interface::ppp->get_ip_address(NSAPI_IPv4);
+        if (ipv4_addr) {
+            ip_addr_t ip_addr;
+            ip_addr_t netmask;
+            ip_addr_t gateway;
+
+            int conv_ip = 0;
+            if (convert_mbed_addr_to_lwip(&ip_addr, ipv4_addr)) {
+                conv_ip++;
+            }
+
+            const nsapi_addr_t *ipv4_netmask = LWIP::Interface::ppp->get_netmask();
+            if (ipv4_netmask && convert_mbed_addr_to_lwip(&netmask, ipv4_netmask)) {
+                conv_ip++;
+            }
+
+            const nsapi_addr_t *ipv4_gateway = LWIP::Interface::ppp->get_gateway();
+            if (ipv4_gateway && convert_mbed_addr_to_lwip(&gateway, ipv4_gateway)) {
+                conv_ip++;
+            }
+
+            if (conv_ip == 3) {
+                netif_set_addr(&netif, ip_2_ip4(&ip_addr), ip_2_ip4(&netmask), ip_2_ip4(&gateway));
+            }
+
+            unsigned char dns_index = 0;
+
+            for (unsigned char index = 0; index < 2; index++) {
+                ip_addr_t dns_server;
+                const nsapi_addr_t *ipv4_dns_server = LWIP::Interface::ppp->get_dns_server(index);
+                if (ipv4_dns_server && convert_mbed_addr_to_lwip(&dns_server, ipv4_dns_server)) {
+                    dns_setserver(dns_index++, &dns_server, &netif);
+                }
+            }
+        }
+#endif
+        // Read negotiated MTU
+        uint32_t mtu = LWIP::Interface::ppp->get_mtu_size();
+        netif.mtu = mtu;
+#if PPP_IPV6_SUPPORT && LWIP_IPV6 && LWIP_ND6_ALLOW_RA_UPDATES
+        netif.mtu6 = mtu;
+#endif
+        tcpip_callback_with_block((tcpip_callback_fn)netif_set_link_up, &netif, 1);
+    } else {
+        tcpip_callback_with_block((tcpip_callback_fn)netif_set_link_down, &netif, 1);
+    }
+}
+
+err_t LWIP::Interface::ppp_if_init(struct netif *netif)
+{
+    int err = ERR_OK;
+    LWIP::Interface *mbed_if = static_cast<LWIP::Interface *>(netif->state);
+
+    mbed_if->ppp->set_memory_manager(*mbed_if->memory_manager);
+    mbed_if->ppp->set_link_input_cb(mbed::callback(mbed_if, &LWIP::Interface::ppp_input));
+    mbed_if->ppp->set_link_state_cb(mbed::callback(mbed_if, &LWIP::Interface::ppp_state_change));
+
+    /* Interface capabilities */
+    netif->flags = NETIF_FLAG_BROADCAST;
+
+    if (!mbed_if->ppp->power_up()) {
+        err = ERR_IF;
+    }
+
+    netif->mtu = mbed_if->ppp->get_mtu_size();
+    mbed_if->ppp->get_ifname(netif->name, NSAPI_INTERFACE_PREFIX_SIZE);
+
+#if PPP_IPV4_SUPPORT && LWIP_IPV4
+    netif->output = &LWIP::Interface::ppp4_output;
+#endif /* PPP_IPV4_SUPPORT */
+#if PPP_IPV6_SUPPORT && LWIP_IPV6
+    netif->output_ip6 = &LWIP::Interface::ppp6_output;
+#endif
+    netif->linkoutput = NULL;
+
+    return err;
+}
+
+#endif
+
+