Network source will alert when network goes down

Only transition from up to down is alerted. If there are no initial network no alert will be triggered. There is no "positive" alert from down to up, perhaps that is wanted..
2hdddg · Feb 9, 2024 · d2cc935 · d2cc935
1 parent 1ed6504
commit d2cc935
Show file tree

Hide file tree

Showing 5 changed files with 60 additions and 19 deletions.
diff --git a/src/NetworkSource.cpp b/src/NetworkSource.cpp
@@ -30,7 +30,7 @@ static char *get_ip_str(const struct sockaddr *sa, char *s, size_t maxlen) {
 
     return s;
 }
-std::shared_ptr<NetworkSource> NetworkSource::Create(MainLoop &mainLoop) {
+std::shared_ptr<NetworkSource> NetworkSource::Create(std::shared_ptr<MainLoop> mainloop) {
     auto sock = socket(PF_INET, SOCK_DGRAM, 0);
     if (sock < 0) {
         return nullptr;
@@ -47,12 +47,15 @@ std::shared_ptr<NetworkSource> NetworkSource::Create(MainLoop &mainLoop) {
         spdlog::error("Failed to set timer: {}", strerror(errno));
         return nullptr;
     }
-    auto source = std::shared_ptr<NetworkSource>(new NetworkSource(sock, fd));
-    mainLoop.RegisterIoHandler(fd, "NetworkSource", source);
+    auto source = std::shared_ptr<NetworkSource>(new NetworkSource(mainloop, sock, fd));
+    mainloop->RegisterIoHandler(fd, "NetworkSource", source);
     return source;
 }
 
-void NetworkSource::Initialize() { ReadState(); }
+void NetworkSource::Initialize() {
+    ReadState();
+    m_drawn = m_published = false;
+}
 
 void NetworkSource::ReadState() {
     char buf[8192] = {0};
@@ -65,7 +68,15 @@ void NetworkSource::ReadState() {
     }
     auto ifr = ifc.ifc_req;
     auto nInterfaces = ifc.ifc_len / sizeof(struct ifreq);
-    Networks networks;
+    bool alerted = false;
+    bool changed = false;
+    // Note that only interfaces that are up is iterated here
+    // so to detect interfaces that were up but now is down, clear
+    // all interfaces first
+    for (auto &keyValue : m_networks) {
+        auto &network = keyValue.second;
+        network.isUp = false;
+    }
     for (unsigned long i = 0; i < nInterfaces; i++) {
         auto item = &ifr[i];
         auto addr = &item->ifr_addr;
@@ -79,19 +90,44 @@ void NetworkSource::ReadState() {
         }
         // extended flags SIOCGIFPFLAGS
         // SIOCGIWSTATS
-        NetworkState network = {};
+        NetworkState network = {.isAlerted = false};
         network.isUp = (item->ifr_flags & IFF_UP) != 0;
         // Get interface address
         if (ioctl(m_socket, SIOCGIFADDR, item) < 0) {
             continue;
         }
-        network.interface = item->ifr_name;
         network.address = get_ip_str(addr, ip, sizeof(ip));
-        networks.push_back(std::move(network));
+        if (m_networks.contains(item->ifr_name)) {
+            // Existing network. Might have changed from down -> up
+            // or changed address.
+            auto &existing = m_networks[item->ifr_name];
+            if (existing != network) {
+                changed = true;
+                m_networks[item->ifr_name] = std::move(network);
+            } else {
+                existing.isUp = true;
+                existing.isAlerted = false;
+            }
+        } else {
+            // New network
+            m_networks[item->ifr_name] = std::move(network);
+            changed = true;
+            // Is this an alert? A positive one perhaps.
+        }
+    }
+    // Check if there is any networks that has gone down
+    for (auto &keyValue : m_networks) {
+        auto &network = keyValue.second;
+        if (!network.isUp && !network.isAlerted) {
+            network.isAlerted = true;
+            alerted = true;
+            changed = true;
+        }
     }
-    if (m_networks != networks) {
-        m_drawn = m_published = false;
-        m_networks = networks;
+    m_drawn = m_published = !changed;
+    if (alerted) {
+        spdlog::info("Network source is triggering alert");
+        m_mainloop->AlertAndWakeup();
     }
 }
 

diff --git a/src/NetworkSource.h b/src/NetworkSource.h
@@ -8,16 +8,18 @@
 
 class NetworkSource : public Source, public IoHandler {
    public:
-    static std::shared_ptr<NetworkSource> Create(MainLoop& mainLoop);
+    static std::shared_ptr<NetworkSource> Create(std::shared_ptr<MainLoop> mainloop);
     void Initialize();
-    void ReadState();
     virtual bool OnRead() override;
     void Publish(const std::string_view sourceName, ScriptContext& scriptContext) override;
     virtual ~NetworkSource() { close(m_timerfd); }
 
    private:
-    NetworkSource(int socket, int timerfd) : Source(), m_socket(socket), m_timerfd(timerfd) {}
+    NetworkSource(std::shared_ptr<MainLoop> mainloop, int socket, int timerfd)
+        : Source(), m_mainloop(mainloop), m_socket(socket), m_timerfd(timerfd) {}
+    void ReadState();
 
+    std::shared_ptr<MainLoop> m_mainloop;
     int m_socket;
     int m_timerfd;
     std::shared_ptr<ScriptContext> m_scriptContext;

diff --git a/src/ScriptContext.cpp b/src/ScriptContext.cpp
@@ -379,10 +379,12 @@ void ScriptContextImpl::Publish(const std::string_view name, const KeyboardState
 }
 void ScriptContextImpl::Publish(const std::string_view name, const Networks& networks) {
     auto networksTable = m_lua.create_table();
-    for (const auto& network : networks) {
+    for (const auto& keyValue : networks) {
+        const auto& interface = keyValue.first;
+        const auto& network = keyValue.second;
         auto networkTable = m_lua.create_table();
         networkTable["up"] = network.isUp;
-        networkTable["interface"] = network.interface;
+        networkTable["interface"] = interface;
         networkTable["address"] = network.address;
         networksTable.add(networkTable);
     }

diff --git a/src/ScriptContext.h b/src/ScriptContext.h
@@ -1,5 +1,6 @@
 #pragma once
 
+#include <map>
 #include <memory>
 
 #include "src/Configuration.h"
@@ -61,15 +62,15 @@ struct KeyboardState {
 };
 
 struct NetworkState {
+    bool isAlerted;
     bool isUp;
-    std::string interface;
     std::string address;
     // type (eth, wifi)
     // wifi strength
 
     auto operator<=>(const NetworkState& other) const = default;
 };
-using Networks = std::vector<NetworkState>;
+using Networks = std::map<std::string, NetworkState>;
 
 class ScriptContext {
    public:

diff --git a/src/main.cpp b/src/main.cpp
@@ -57,7 +57,7 @@ static void InitializeSource(const std::string& source, Sources& sources,
         return;
     }
     if (source == "networks") {
-        auto networkSource = NetworkSource::Create(*mainLoop);
+        auto networkSource = NetworkSource::Create(mainLoop);
         if (!networkSource) {
             spdlog::error("Failed to initialize network source");
             return;