Add passive mode (only for localhost) and fix random thread crashes

src/client.cpp

@@ -8,6 +8,7 @@
 #include <arpa/inet.h>
 #include <sys/stat.h>
 #include <time.h>
+#include <thread>
 
 #include "server.h"
 #include "filer.cpp"
@@ -25,6 +26,7 @@ public:
 	 *  2 - Waiting for data
 	 */
 	int state = 0;
+	std::thread thread;
 
 	Client(int &_sock) {
 		control_sock = _sock;
@@ -37,7 +39,7 @@ public:
 			return -1;
 		} else if (state > 0) {
 			if (cmd == "SYST") {
-				submit(215, "UNIX");
+				submit(215, "UNIX Type: L8");
 			} else if (cmd == "PWD") {
 				submit(257, "'"+filer->cwd.string()+"'");
 			} else if (cmd == "CWD") {
@@ -69,7 +71,76 @@ public:
 				sscanf(argstr.c_str(), "%c", &(filer->type));
 				submit(226, "OK");
 			} else if (cmd == "PASV") {
-				submit(502, "Command not implemented");
+				if ((data_fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
+					perror("pasv socket() failed");
+					return -1;
+				}
+				
+				if (setsockopt(data_fd, SOL_SOCKET, SO_REUSEADDR | SO_REUSEPORT, (char *)&opt, sizeof(opt)) < 0) {
+					perror("pasv setsockopt() failed");
+					close(data_fd);
+					return -1;
+				}
+				
+				uint16_t dataport;
+				uint8_t netaddr[4];
+				uint8_t netport[2];
+				socklen_t datalen = sizeof(data_address);
+				
+				data_address.sin_family = AF_INET;
+				data_address.sin_addr.s_addr = INADDR_ANY;
+				data_address.sin_port = 0;
+				
+				if (bind(data_fd, (struct sockaddr *)&data_address, sizeof(data_address)) < 0) {
+					perror("pasv bind() failed");
+					close(data_fd);
+					return -1;
+				}
+				
+				if (listen(data_fd, 3) < 0) {
+					perror("pasv listen() failed");
+					close(data_fd);
+					return -1;
+				}
+				
+				if (getsockname(data_fd, (struct sockaddr *)&data_address, &datalen) == 0) {
+					//memcpy(&netaddr[0], &data_address.sin_addr, 4);
+					netaddr[0] = 127;
+					netaddr[1] = netaddr[2] = 0;
+					netaddr[3] = 1;
+					dataport = ntohs(data_address.sin_port);
+					memcpy(&netport[0], &dataport, 2);
+					printf("[i] D(%i) PASV initialized: %u.%u.%u.%u:%u\n", data_fd, netaddr[0], netaddr[1], netaddr[2], netaddr[3], dataport);
+				} else {
+					perror("pasv getpeername() failed");
+					close(data_fd);
+					return -1;
+				}
+				
+				char* pasvok;
+				asprintf(
+					&pasvok,
+					"Entering Passive Mode (%u,%u,%u,%u,%u,%u)",
+					netaddr[0],
+					netaddr[1],
+					netaddr[2],
+					netaddr[3],
+					netport[1],
+					netport[0]
+				);
+				
+				submit(227, std::string(pasvok));
+				free(pasvok);
+				
+				if ((data_sock = accept(data_fd, NULL, NULL)) >= 0) {
+					printf("[i] D(%i) PASV accepted: %i\n", data_fd, data_sock);
+					state = 2;
+					//submit(200, "OK");
+				} else {
+					perror("accept() failed");
+					submit(425, "Unknown Error");
+					data_close();
+				}
 			} else if (cmd == "PORT") {
 				data_sock = socket(AF_INET, SOCK_STREAM, 0);
 				
@@ -79,16 +150,15 @@ public:
 				sscanf(argstr.c_str(), "%d,%d,%d,%d,%d,%d", &act_ip[0], &act_ip[1], &act_ip[2], &act_ip[3], (int*)&act_port[0], (int*)&act_port[1]);
 				sprintf(ip_decimal, "%d.%d.%d.%d", act_ip[0], act_ip[1], act_ip[2], act_ip[3]);
 				port_dec = act_port[0]*256+act_port[1];
-				printf("[d] D(%i) Initialized data transport: %s:%d\n", control_sock, ip_decimal, port_dec);
+				printf("[d] D(%i) PORT initialized: %s:%d\n", control_sock, ip_decimal, port_dec);
 				
 				data_address.sin_family = AF_INET;
 				data_address.sin_addr.s_addr = inet_addr(ip_decimal);
 				data_address.sin_port = htons(port_dec);
 						
 				if (connect(data_sock, (struct sockaddr *)&data_address, sizeof(data_address)) != 0) {
-					close(data_sock);
-					data_sock = 0;
 					submit(425, "Unknown Error");
+					data_close();
 				} else {
 					state = 2;
 					submit(200, "OK");
@@ -152,9 +222,7 @@ public:
 					}
 					submit(226, "OK");
 				}
-				if (data_close() != 0) {
+				data_close();
-					printf("[!] Data Sock returned %i instead of 0! Not closed!!!\n", data_sock);
-				}
 			} else {
 				submit(502, "Command not implemented");
 			}
@@ -205,17 +273,22 @@ public:
 	}
 	
 	int data_close() {
+		if (data_sock <= 0) return 0;
 		printf("[d] D(%i) Closing...\n", data_sock);
 		close(data_sock);
-		data_sock = 0;
+		data_sock = -1;
+		close(data_fd);
+		data_fd = -1;
 		state = 1;
-		return data_sock; // Should be 0 if successful.
+		return 0;
 	}
 	
 private:
 	std::string name;
 	Filer* filer = new Filer();
+	const int opt = 1;
 	
+	int data_fd;
 	int data_sock;
 	struct sockaddr_in data_address;
 };

src/main.cpp

@@ -28,7 +28,6 @@ using namespace std::chrono_literals;
 struct pollfd fds[MAXCLIENTS];
 struct clientfd {
 	Client* client;
-	std::thread thread;
 	bool close = false;
 } fdc[MAXCLIENTS];
 
@@ -38,6 +37,7 @@ void runClient(struct clientfd* cfd) {
 	char inbuf[BUFFERSIZE];
 	printf("[d] C(%i) Initialized\n", cfd->client->control_sock);
 	// Loop as long as it is a valid file descriptor.
+	try {
 	while (fcntl(cfd->client->control_sock, F_GETFD) != -1) {
 		printf("[d] C(%i) Attempting read...\n", cfd->client->control_sock);
 		int rc = recv(cfd->client->control_sock, inbuf, sizeof(inbuf), 0);
@@ -67,9 +67,12 @@ void runClient(struct clientfd* cfd) {
 		if (cfd->client->receive(cmd, args) < 0) break;
 		inbuf[0] = '\0';
 	}
+	} catch (...) {
+		printf("[!] C(%i) Caught error!\n", cfd->client->control_sock);
+	}
+	cfd->client->thread.detach();
 	printf("[d] C(%i) Marking for deletion...\n", cfd->client->control_sock);
 	cfd->close = true;
-	cfd->thread.detach();
 }
 
 int main(int argc , char *argv[]) {
@@ -79,10 +82,9 @@ int main(int argc , char *argv[]) {
 		nfds = 1,
 		current_size = 0;
 	
-	char inbuf[BUFFERSIZE];
 	struct sockaddr_in ctrl_address;
 	
-	if ((master_socket = socket(AF_INET , SOCK_STREAM , 0)) < 0) {
+	if ((master_socket = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
 		perror("socket() failed");
 		exit(-1);
 	}
@@ -137,8 +139,6 @@ int main(int argc , char *argv[]) {
 		
 		current_size = nfds;
 		for (int i = 0; i < current_size; i++) {
-			inbuf[0] = '\0';
-			
 			if(fds[i].revents == 0)
 				continue;
 			
@@ -158,56 +158,22 @@ int main(int argc , char *argv[]) {
 						break;
 					}
 					
-					printf("[d] C(%i) Accepted client%i\n", newsock);
+					printf("[d] C(%i) Accepted client\n", newsock);
-					// If we assign thead if it is still attached,
-					// we suffer greatly, and by we I mean me.
-					if (fdc[nfds].thread.joinable()) {
-						printf("[!] C(%i) Thread still joinable! Detaching...\n", newsock);
-						// Pray the thread will end itself.
-						fdc[nfds].thread.detach();
-					}
 					fds[nfds].fd = newsock;
 					fds[nfds].events = POLLIN;
+					fdc[nfds].close = false;
 					fdc[nfds].client = new Client(newsock);
-					fdc[nfds].thread = std::thread(runClient, &fdc[nfds]);
+					fdc[nfds].client->thread = std::thread(runClient, &fdc[nfds]);
 					nfds++;
 				} while (newsock != -1);
 			} else {
-				/*
-				int rc = recv(fds[i].fd, inbuf, sizeof(inbuf), 0);
-				if (rc < 0) {
-					if (errno != EWOULDBLOCK) {
-						perror("recv() failed");
-						fdc[i].close = true;
-					}
-					continue;
-				}
-				
-				if (rc == 0 || fdc[i].client == nullptr) {
-					printf("[d] (%i) closed\n", fds[i].fd);
-					fdc[i].close = true;
-				}
-				
-				std::string lin(inbuf);
-				int len = lin.find("\r\n", 0);
-				int cmdend = lin.find(" ", 0);
-				if (cmdend >= len || cmdend == std::string::npos) cmdend = len;
-				std::string cmd = toUpper(lin.substr(0, cmdend));
-				std::string args = "";
-				if (len > cmdend) args = lin.substr(cmdend+1, len-cmdend-1);
-				
-				printf("[d] (%i) >> '%s' '%s'\n", fds[i].fd, cmd.c_str(), args.c_str());
-				
-				if (fdc[i].client->receive(cmd, args) < 0) fdc[i].close = true;
-				inbuf[0] = '\0';
-				*/
-				
 				if (fdc[i].close) {
 					conn_close:
 					printf("[d] C(%i) Deleting client...\n", fds[i].fd);
 					close(fds[i].fd);
 					fds[i].fd = -1;
-					if (fdc[i].thread.joinable()) fdc[i].thread.detach();
+					if (fdc[i].client->thread.joinable())
+						fdc[i].client->thread.detach();
 					fdc[i].client = nullptr;
 					fdc[i].close = false;
 					compress_array = true;
@@ -217,18 +183,19 @@ int main(int argc , char *argv[]) {
 	
 		if (compress_array) {
 			compress_array = false;
-			printf("[d] Compressing...\n");
 			for (int i = 0; i < nfds; i++) {
 				if (fds[i].fd == -1) {
 					for(int j = i; j < nfds; j++) {
-						printf("[d] Compressing: id %i to fd %i\n", j, fds[j+1].fd);
+						if (fds[j].fd == -1) {
-						fds[j].fd = fds[j+1].fd;
+							printf("[d] Compressing: %i(fd:%i) <= %i(fd:%i)\n", j, fds[j].fd, j+1, fds[j+1].fd);
+							fds[j].fd = fds[j+1].fd;
+							fdc[j].client = fdc[j+1].client;
+						}
 					}
 					i--;
 					nfds--;
 				}
 			}
-			printf("[d] Compressing complete!\n");
 		}
 	}
 	return 0;