From b9a6dc2a856f02db18f7e73bb8dffe54800f0676 Mon Sep 17 00:00:00 2001
From: Alexander Lunev <alexanderlunev@mail.ru>
Date: Tue, 4 Jan 2022 09:29:05 +0300
Subject: [PATCH] netutils/netcat: implemented NETUTILS_NETCAT_SENDFILE option.
 This option enables using sendfile() in netcat client mode if a normal file
 (not stdin) is sent. If the option is enabled but stdin is sent rather than a
 normal file, netcat falls back to the combination of read() and write().
 Using sendfile() provides a higher performance compared to the combination of
 read() and write().

Also this option is useful for testing / debugging tcp_sendfile()
functionality of NuttX TCP/IP stack.
---
 netutils/netcat/Kconfig       | 12 +++++++++
 netutils/netcat/netcat_main.c | 46 ++++++++++++++++++++++++++++++++++-
 2 files changed, 57 insertions(+), 1 deletion(-)

diff --git a/netutils/netcat/Kconfig b/netutils/netcat/Kconfig
index 431706907..d24e03364 100644
--- a/netutils/netcat/Kconfig
+++ b/netutils/netcat/Kconfig
@@ -47,4 +47,16 @@ config NETUTILS_NETCAT_STACKSIZE
 	int "netcat stack size"
 	default DEFAULT_TASK_STACKSIZE
 
+config NETUTILS_NETCAT_SENDFILE
+	bool "Use sendfile() in netcat when possible"
+	default y
+	depends on NET_SENDFILE
+	---help---
+		This option enables using sendfile() in netcat client mode
+		if a normal file (not stdin) is sent. If the option is enabled
+		but stdin is sent rather than a normal file, netcat falls back
+		to the combination of read() and write().
+		Using sendfile() provides a higher performance compared to
+		the combination of read() and write().
+
 endif
diff --git a/netutils/netcat/netcat_main.c b/netutils/netcat/netcat_main.c
index 95c20e284..a345afac3 100644
--- a/netutils/netcat/netcat_main.c
+++ b/netutils/netcat/netcat_main.c
@@ -31,7 +31,9 @@
 #include <unistd.h>
 #include <string.h>
 
+#include <sys/sendfile.h>
 #include <sys/socket.h>
+#include <sys/stat.h>
 #include <arpa/inet.h>
 
 /****************************************************************************
@@ -166,6 +168,11 @@ int netcat_client(int argc, char * argv[])
   char *host = "127.0.0.1";
   int port = NETCAT_PORT;
   int result = EXIT_SUCCESS;
+#ifdef CONFIG_NETUTILS_NETCAT_SENDFILE
+  struct stat stat_buf;
+  off_t offset;
+  ssize_t len;
+#endif
 
   if (argc > 1)
     {
@@ -187,6 +194,16 @@ int netcat_client(int argc, char * argv[])
           result = 1;
           goto out;
         }
+
+#ifdef CONFIG_NETUTILS_NETCAT_SENDFILE
+      if (fstat(infd, &stat_buf) == -1)
+        {
+          perror("fstat");
+          infd = STDIN_FILENO;
+          result = 1;
+          goto out;
+        }
+#endif
     }
 
   id = socket(AF_INET , SOCK_STREAM , 0);
@@ -214,7 +231,34 @@ int netcat_client(int argc, char * argv[])
       goto out;
     }
 
-  result = do_io(infd, id);
+#ifdef CONFIG_NETUTILS_NETCAT_SENDFILE
+  if (argc > 3)
+    {
+      len = stat_buf.st_size;
+      offset = 0;
+
+      while (len > 0)
+        {
+          result = sendfile(id, infd, &offset, len);
+
+          if (result == -1 && errno == EAGAIN)
+            {
+              continue;
+            }
+          else if (result == -1)
+            {
+              perror("sendfile error");
+              break;
+            }
+
+          len -= result;
+        }
+    }
+  else
+#endif
+    {
+      result = do_io(infd, id);
+    }
 
 out:
   if (id != -1)