udp wip

src/core.c

@@ -423,6 +423,52 @@ static int tunnel_to(int sock, ip_type ip, unsigned short port, proxy_type pt, c
 	return SOCKET_ERROR;
 }
 
+
+/* Given a socket connected to a SOCKS5 proxy server, performs a UDP_ASSOCIATE handshake and returns BND_ADDR and BND_PORT if successfull*/
+static int udp_associate(int sock, ip_type dst_addr, unsigned short dst_port, ip_type *bnd_addr, unsigned short *bnd_port, char *user, char *pass){
+	//TODO hugoc
+	return SUCCESS;
+}
+
+/* Fills buf with the SOCKS5 udp request header for the target dst_addr:dst_port*/
+static int udp_header(socks5_addr dst_addr, unsigned short dst_port , char frag, char * buf, size_t buflen) {
+
+	if (buflen <= 262) { //TODO: make something cleaner
+		return -1;
+	}
+
+	int buf_iter = 0;
+	buf[buf_iter++] = 0;	// reserved
+	buf[buf_iter++] = 0;	// reserved
+	buf[buf_iter++] = frag;	// frag
+	buf[buf_iter++] = dst_addr.atyp;	// atyp
+
+	int v6 = dst_addr.atyp == ATYP_V6;
+	switch (dst_addr.atyp){
+		case ATYP_V6:
+		case ATYP_V4:
+			memcpy(buf + buf_iter, dst_addr.addr.v6, v6?16:4);
+			buf_iter += v6?16:4;
+			break;
+	
+		case ATYP_DOM:
+			buf[buf_iter++] = dst_addr.addr.dom.len;
+			memcpy(buf + buf_iter, dst_addr.addr.dom.name, dst_addr.addr.dom.len);
+			buf_iter += dst_addr.addr.dom.len;
+			break;
+	}
+
+	memcpy(buf + buf_iter, &dst_port, 2);	// dest port
+	buf_iter += 2;
+	
+	return buf_iter;
+}
+
+static int encapsulate_udp_packet(udp_relay_chain rcd, ip_type target_addr, unsigned short target_port, char frag) {
+
+}
+
+
 #define TP " ... "
 #define DT "Dynamic chain"
 #define ST "Strict chain"

src/core.h

@@ -64,6 +64,7 @@ typedef enum {
 	FIFOLY
 } select_type;
 
+
 typedef struct {
 	sa_family_t family;
 	unsigned short port;
@@ -93,6 +94,43 @@ typedef struct {
 	char pass[256];
 } proxy_data;
 
+
+
+typedef enum {
+	ATYP_V4 = 0x01,
+	ATYP_V6 = 0x04,
+	ATYP_DOM = 0x03
+} ATYP;
+
+typedef struct{
+	ATYP atyp;
+	union {
+		ip_type4 v4;
+		unsigned char v6[16];
+		struct {
+			char len;
+			char name[255];
+		} dom;
+	} addr ;
+} socks5_addr;
+
+/* A structure to hold necessary information about an UDP relay server that has been set up 
+with a UDP_ASSOCIATE command issued on the tcp_sockfd */
+typedef struct {
+	int tcp_sockfd;	// the tcp socket on which the UDP_ASSOCIATE command has been issued. Closing this fd closes the udp relay.
+	socks5_addr bnd_addr; // the BND_ADDR returned by the udp relay server in the response to the UDP_ASSOCIATE command. 
+	unsigned short bnd_port; // the BND_PORT returned by the udp relay server in the response to the UDP_ASSOCIATE command.
+	socks5_addr dst_addr; // ?? the DST_ADDR sent in the UDP_ASSOCIATE command.
+	unsigned short dst_port; // ?? the DST_PORT sent in the UDP_ASSOCIATE command.
+} udp_relay_data;
+
+/* A structure to hold the chain of udp relay servers assiociated with a client socket */
+typedef struct {
+	int sockfd; // the client socket for which the chain of relays has been set up
+	udp_relay_data * ud; // an array of relay, ud[0] being the closest to the client and u[len(ud)-1] the closest to the targets  
+	unsigned int relay_count; 
+} udp_relay_chain;
+
 int connect_proxy_chain (int sock, ip_type target_ip, unsigned short target_port,
 			 proxy_data * pd, unsigned int proxy_count, chain_type ct,
 			 unsigned int max_chain );
@@ -147,6 +185,8 @@ void proxy_freeaddrinfo(struct addrinfo *res);
 void core_initialize(void);
 void core_unload(void);
 
+static int udp_associate(int sock, ip_type dst_addr, unsigned short dst_port, ip_type *bnd_addr, unsigned short *bnd_port, char *user, char *pass);
+
 #include "debug.h"
 
 #endif

src/libproxychains.c

@@ -902,12 +902,15 @@ HOOKFUNC(ssize_t, sendto, int sockfd, const void *buf, size_t len, int flags,
 		addrlen = 0;
 		flags &= ~MSG_FASTOPEN;
 	}
+	//TODO hugoc: case of SOCK_DGRAM with AF_INET or AF_INET6
+
 	return true_sendto(sockfd, buf, len, flags, dest_addr, addrlen);
 }
 
 HOOKFUNC(ssize_t, recv, int sockfd, void *buf, size_t len, int flags){
 	INIT();
 	PFUNC();
+	//TODO hugoc
 	return true_recv(sockfd, buf, len, flags);
 }
 
@@ -915,12 +918,14 @@ HOOKFUNC(ssize_t, recvfrom, int sockfd, void *buf, size_t len, int flags,
 			struct sockaddr *src_addr, socklen_t *addrlen){
 	INIT();
 	PFUNC();
+	//TODO hugoc
 	return true_recvfrom(sockfd, buf, len, flags, src_addr, addrlen);
 }
 
 HOOKFUNC(ssize_t, send, int sockfd, const void *buf, size_t len, int flags){
 	INIT();
 	PFUNC();
+	//TODO hugoc
 	return true_send(sockfd, buf, len, flags);
 }