From b360ed2a7bdf03d20b7ba59e656ff7e4ffa63b9b Mon Sep 17 00:00:00 2001
From: Bryan Biedenkapp <gatekeep@gmail.com>
Date: Fri, 12 May 2023 15:00:48 -0400
Subject: [PATCH] update detection for sendmsg and sendmmsg (handles some
 platforms that don't define sendmmsg);

---
 CMakeLists.txt          | 22 ++++++++++++++++++++++
 src/network/UDPSocket.h | 23 +++++++++++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index a6a8a503..ec94671d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -98,6 +98,8 @@ file(GLOB dvmhost_SRC
     "src/host/calibrate/*.cpp"
     "src/host/setup/*.h"
     "src/host/setup/*.cpp"
+    "src/host/fne/*.h"
+    "src/host/fne/*.cpp"
     "src/lookups/*.h"
     "src/lookups/*.cpp"
     "src/modem/*.h"
@@ -106,6 +108,8 @@ file(GLOB dvmhost_SRC
     "src/modem/port/*.cpp"
     "src/network/*.h"
     "src/network/*.cpp"
+    "src/network/fne/*.h"
+    "src/network/fne/*.cpp"
     "src/network/json/*.h"
     "src/network/rest/*.h"
     "src/network/rest/*.cpp"
@@ -401,6 +405,24 @@ target_include_directories(asio::asio INTERFACE ${ASIO_INCLUDE_DIR})
 target_compile_definitions(asio::asio INTERFACE "ASIO_STANDALONE")
 target_link_libraries(asio::asio INTERFACE Threads::Threads)
 
+# Check if platform-specific functions exist
+include(CheckCXXSymbolExists)
+check_cxx_symbol_exists(sendmsg sys/socket.h HAVE_SENDMSG)
+check_cxx_symbol_exists(sendmmsg sys/socket.h HAVE_SENDMMSG)
+
+if(HAVE_SENDMSG)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DHAVE_SENDMSG=1")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DHAVE_SENDMSG=1")
+    set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -DHAVE_SENDMSG=1")
+    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -DHAVE_SENDMSG=1")
+endif()
+if(HAVE_SENDMMSG)
+    set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -DHAVE_SENDMMSG=1")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DHAVE_SENDMMSG=1")
+    set(CMAKE_C_FLAGS_RELEASE "${CMAKE_C_FLAGS_RELEASE} -DHAVE_SENDMMSG=1")
+    set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -DHAVE_SENDMMSG=1")
+endif()
+
 add_executable(dvmhost ${dvmhost_SRC})
 target_include_directories(dvmhost PRIVATE src)
 target_link_libraries(dvmhost PRIVATE asio::asio Threads::Threads util)
diff --git a/src/network/UDPSocket.h b/src/network/UDPSocket.h
index f1e79a59..df57a012 100644
--- a/src/network/UDPSocket.h
+++ b/src/network/UDPSocket.h
@@ -62,6 +62,29 @@ enum IPMATCHTYPE {
 
 namespace network
 {
+#if defined(HAVE_SENDMSG) && !defined(HAVE_SENDMMSG)
+    struct mmsghdr {
+        struct msghdr msg_hdr;
+        unsigned int msg_len;
+    };
+
+    static inline int sendmmsg(int sockfd, struct mmsghdr* msgvec, unsigned int vlen, int flags)
+    {
+        ssize_t n = 0;
+        for (unsigned int i = 0; i < vlen; i++) {
+            ssize_t ret = sendmsg(sockfd, &msgvec[i].msg_hdr, flags);
+            if (ret < 0)
+                break;
+            n += ret;
+        }
+
+        if (n == 0)
+            return -1;
+
+        return int(n);
+    }
+#endif
+
     /* Vector of buffers that contain a full frames */
     typedef std::vector<std::pair<size_t, uint8_t*>> BufferVector;