Add QR code pairing

src/platform/common.h

@@ -567,6 +567,9 @@ namespace platf {
   std::string
   get_mac_address(const std::string_view &address);
 
+  std::string
+  get_local_ip_for_gateway();
+
   std::string
   from_sockaddr(const sockaddr *const);
   std::pair<std::uint16_t, std::string>

src/platform/linux/misc.cpp

@@ -239,6 +239,83 @@ namespace platf {
     return "00:00:00:00:00:00"s;
   }
 
+  std::string
+  get_local_ip_for_gateway() {
+    int fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+    if (fd < 0) {
+      BOOST_LOG(warning) << "Socket creation failed";
+      return "";
+    }
+
+    char buffer[8192];
+    struct nlmsghdr *nlMsg = (struct nlmsghdr *)buffer;
+    struct rtmsg *rtMsg = (struct rtmsg *)NLMSG_DATA(nlMsg);
+    struct rtattr *rtAttr;
+    int len = 0;
+
+    memset(nlMsg, 0, sizeof(struct nlmsghdr));
+    nlMsg->nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
+    nlMsg->nlmsg_type = RTM_GETROUTE;
+    nlMsg->nlmsg_flags = NLM_F_DUMP | NLM_F_REQUEST;
+    nlMsg->nlmsg_seq = 1;
+    nlMsg->nlmsg_pid = getpid();
+
+    if (send(fd, nlMsg, nlMsg->nlmsg_len, 0) < 0) {
+      close(fd);
+      BOOST_LOG(warning) << "Send message failed";
+      return "";
+    }
+
+    len = recv(fd, nlMsg, sizeof(buffer), 0);
+    if (len < 0) {
+      close(fd);
+      BOOST_LOG(warning) << "Receive message failed";
+      return "";
+    }
+
+    std::string local_ip;
+
+    for (; NLMSG_OK(nlMsg, len); nlMsg = NLMSG_NEXT(nlMsg, len)) {
+      rtMsg = (struct rtmsg *)NLMSG_DATA(nlMsg);
+      if (rtMsg->rtm_family != AF_INET || rtMsg->rtm_table != RT_TABLE_MAIN)
+        continue;
+
+      rtAttr = (struct rtattr *)RTM_RTA(rtMsg);
+      int rtLen = RTM_PAYLOAD(nlMsg);
+
+      in_addr gateway;
+      in_addr local;
+      memset(&gateway, 0, sizeof(gateway));
+      memset(&local, 0, sizeof(local));
+
+      for (; RTA_OK(rtAttr, rtLen); rtAttr = RTA_NEXT(rtAttr, rtLen)) {
+        switch(rtAttr->rta_type) {
+          case RTA_GATEWAY:
+            gateway.s_addr = *reinterpret_cast<uint32_t *>(RTA_DATA(rtAttr));
+            break;
+          case RTA_PREFSRC:
+            local.s_addr = *reinterpret_cast<uint32_t *>(RTA_DATA(rtAttr));
+            break;
+          default:
+            break;
+        }
+      }
+
+      if (gateway.s_addr != 0 && local.s_addr != 0) {
+          local_ip = inet_ntoa(local);
+          break;
+      }
+    }
+
+    close(fd);
+
+    if (local_ip.empty()) {
+        BOOST_LOG(warning) << "No associated IP address found for the default gateway";
+    }
+
+    return local_ip;
+}
+
   bp::child
   run_command(bool elevated, bool interactive, const std::string &cmd, boost::filesystem::path &working_dir, const bp::environment &env, FILE *file, std::error_code &ec, bp::group *group) {
     if (!group) {

src/platform/macos/misc.mm

@@ -168,6 +168,12 @@ namespace platf {
     return "00:00:00:00:00:00"s;
   }
 
+  // TODO: return actual IP
+  std::string
+  get_local_ip_for_gateway() {
+    return "";
+  }
+
   bp::child
   run_command(bool elevated, bool interactive, const std::string &cmd, boost::filesystem::path &working_dir, const bp::environment &env, FILE *file, std::error_code &ec, bp::group *group) {
     if (!group) {

src/platform/windows/misc.cpp

@@ -190,6 +190,62 @@ namespace platf {
     return "00:00:00:00:00:00"s;
   }
 
+  std::string
+  get_local_ip_for_gateway() {
+    PIP_ADAPTER_INFO pAdapterInfo;
+    PIP_ADAPTER_INFO pAdapter = nullptr;
+    DWORD dwRetVal = 0;
+    ULONG ulOutBufLen = sizeof(IP_ADAPTER_INFO);
+
+    pAdapterInfo = (IP_ADAPTER_INFO *)malloc(sizeof(IP_ADAPTER_INFO));
+    if (pAdapterInfo == nullptr) {
+      BOOST_LOG(warning) << "Error allocating memory needed to call GetAdaptersInfo";
+      return "";
+    }
+
+    // Make an initial call to GetAdaptersInfo to get the necessary size into the ulOutBufLen variable
+    if (GetAdaptersInfo(pAdapterInfo, &ulOutBufLen) == ERROR_BUFFER_OVERFLOW) {
+      free(pAdapterInfo);
+      pAdapterInfo = (IP_ADAPTER_INFO *)malloc(ulOutBufLen);
+      if (pAdapterInfo == nullptr) {
+        BOOST_LOG(warning) << "Error allocating memory needed to call GetAdaptersInfo";
+        return "";
+      }
+    }
+
+    if ((dwRetVal = GetAdaptersInfo(pAdapterInfo, &ulOutBufLen)) != NO_ERROR) {
+      if (pAdapterInfo) {
+        free(pAdapterInfo);
+      }
+      BOOST_LOG(warning) << "GetAdaptersInfo failed with error: " + std::to_string(dwRetVal);
+      return "";
+    }
+
+    pAdapter = pAdapterInfo;
+    std::string local_ip;
+
+    // Iterate through the list of adapters
+    while (pAdapter) {
+      IP_ADDR_STRING* pGateway = &pAdapter->GatewayList;
+      if (pGateway && pGateway->IpAddress.String[0] != '\0') {
+        // This adapter has a default gateway, use its IP address
+        local_ip = pAdapter->IpAddressList.IpAddress.String;
+        break;
+      }
+      pAdapter = pAdapter->Next;
+    }
+
+    if (pAdapterInfo) {
+      free(pAdapterInfo);
+    }
+
+    if (local_ip.empty()) {
+      BOOST_LOG(warning) << "No associated IP address found for the default gateway";
+    }
+
+    return local_ip;
+  }
+
   HDESK
   syncThreadDesktop() {
     auto hDesk = OpenInputDesktop(DF_ALLOWOTHERACCOUNTHOOK, FALSE, GENERIC_ALL);