From 9e5b432b18b80e3206cad70c64618b462291d84f Mon Sep 17 00:00:00 2001
From: Jonas Gunz <himself@jonasgunz.de>
Date: Fri, 30 Aug 2019 03:46:11 +0200
Subject: Initial

---
 .gitignore |  4 ++++
 Makefile   | 35 ++++++++++++++++++++++++++++
 src/main.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 118 insertions(+)
 create mode 100644 .gitignore
 create mode 100644 Makefile
 create mode 100644 src/main.c

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..7a75f37
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+*.o
+obj/
+build/
+tags
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..5b3dcac
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,35 @@
+CC              = clang
+CFLAGS          = -Wall
+LDFLAGS         = 
+BUILDDIR        = build
+SOURCEDIR       = src
+OBJECTDIR       = obj
+
+OUTPUT          = dns
+
+SRCS = $(wildcard $(SOURCEDIR)/*.c)
+OBJS = $(SRCS:.c=.o)
+OBJ  = $(OBJS:$(SOURCEDIR)/%=$(OBJECTDIR)/%)
+
+build: dir $(OBJ)
+	@echo [LD] $(OBJ)
+	@$(CC) $(CFLAGS) -o $(BUILDDIR)/$(OUTPUT) $(OBJ) $(LDFLAGS)
+
+debug: CFLAGS += -g -D _DEBUG
+debug: build;
+
+dir:
+	@mkdir -p $(OBJECTDIR)
+	@mkdir -p $(BUILDDIR)
+
+$(OBJECTDIR)/%.o: $(SOURCEDIR)/%.c
+	@echo [CC] $<
+	@$(CC) $(CFLAGS) -c $< -o $@
+
+.PHONY: clean
+
+clean:
+	@echo [RM] $(OBJ)
+	@echo [RM] $(BUILDDIR)/$(OUTPUT)
+	@rm -df  $(OBJ)
+	@rm -Rdf $(BUILDDIR) $(OBJECTDIR)
diff --git a/src/main.c b/src/main.c
new file mode 100644
index 0000000..bf4260f
--- /dev/null
+++ b/src/main.c
@@ -0,0 +1,79 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/types.h>
+
+#include <sys/socket.h>
+#include <netinet/ip.h>
+#include <arpa/inet.h>
+
+#include <unistd.h>
+
+#define PRINT_ERRNO() {printf("%s:%i %i:%s\n", __FILE__, __LINE__, errno, strerror(errno));}
+
+#define UDP_BUFFER_LEN 512
+
+int dns_parse_packet(int _socket, struct sockaddr_in *sockaddr_client, socklen_t sockaddr_client_len, char* buffer);
+
+int main(int argc, char* argv[])
+{
+	int 		ret;
+	int 		sock_server;
+       	struct		sockaddr_in sock_server_addr;
+	
+	char recv_buffer[ UDP_BUFFER_LEN ];
+
+	sock_server = socket ( AF_INET, SOCK_DGRAM, 0 );
+	if ( sock_server == -1 ) {
+		PRINT_ERRNO();
+		return errno;
+	}
+
+	memset( &sock_server_addr, '\0', sizeof(struct sockaddr_in) );
+	sock_server_addr.sin_family = AF_INET;
+	sock_server_addr.sin_port   = htons( 53 );
+	ret = inet_aton ( "0.0.0.0", & sock_server_addr.sin_addr );
+	if( ret == 0 ) {//Error on 0, no errno
+		printf("Invalid IP\n");
+		return 1;
+	}
+
+	ret = bind( sock_server , &sock_server_addr, sizeof(struct sockaddr_in) );
+	if ( ret == -1 ) {
+		PRINT_ERRNO();
+		return errno;
+	}
+
+	//while( 1 )
+	{
+		struct 		sockaddr_in sock_client_addr;
+		socklen_t	sock_client_addr_len;
+
+		sock_client_addr_len = sizeof ( struct sockaddr_in );
+		memset ( &sock_client_addr, '\0', sock_client_addr_len );
+
+		ret = recvfrom ( sock_server, recv_buffer, UDP_BUFFER_LEN, 0, &sock_client_addr, &sock_client_addr_len );
+		if ( ret == -1 ) {
+			PRINT_ERRNO();
+			return errno;
+		}
+	}
+
+	close( sock_server );
+
+	return 0;
+}
+
+
+int dns_parse_packet(int _socket, struct sockaddr_in *sockaddr_client, socklen_t sockaddr_client_len, char* buffer) 
+{
+	pid_t = pid fork();
+	
+	if ( pid == 0)
+		return 0;
+	else if ( pid < 0 )
+		return errno;
+
+	exit (0);
+}
-- 
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