first commit

LICENSE

@@ -0,0 +1,11 @@
+DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
+Version 2, December 2004
+
+Copyright (C) 2004 Sam Hocevar <sam@hocevar.net>
+
+Everyone is permitted to copy and distribute verbatim or modified copies of this license document, and changing it is allowed as long as the name is changed.
+
+DO WHAT THE FUCK YOU WANT TO PUBLIC LICENSE
+TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+  0. You just DO WHAT THE FUCK YOU WANT TO.

Makefile

@@ -0,0 +1,5 @@
+CFLAGS?=-pedantic -O0 -s -Wall
+CC?=cc
+
+all:
+	$(CC) plainbin.c $(CFLAGS) -oplainbin

README.md

@@ -0,0 +1,3 @@
+Send: echo "Hello" | nc ip 8080  
+Get: echo "[code]" | nc ip 8081  
+Server info: echo "INFO" | nc ip 8081  

plainbin.c

@@ -0,0 +1,374 @@
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <signal.h>
+#include <arpa/inet.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <sys/stat.h>
+#include <limits.h>
+#include <time.h>
+
+#define SEND_TIMEOUT 1
+#define RECV_TIMEOUT 2
+#define BUFLEN 1024 * 1024
+#define MSG1 "Server very loaded.\n"
+#define MSG2 "File very big.\n"
+#define MSG3 "Closing connection.\n"
+#define MSG4 "No such file.\n"
+
+int iport = 8080;
+int oport = 8081;
+size_t max_clients = 15;
+size_t max_size = 500;
+size_t name_len = 15;
+char *dir = ".";
+
+char *prog_name;
+int ifd;
+int ifd_clients;
+
+int ofd;
+int ofd_clients;
+
+enum {
+	OUTPUT,
+	INPUT
+};
+
+enum {
+	WRITE,
+	SEND
+};
+
+int new_server(const int port) {
+	int listen_fd = socket(AF_INET, SOCK_STREAM, 0);
+	if (listen_fd < 0)
+		return -1;
+
+	struct timeval tout = {.tv_sec = RECV_TIMEOUT, .tv_usec = 0};
+	if (setsockopt(listen_fd, SOL_SOCKET, SO_RCVTIMEO, &tout, sizeof(tout)) < 0)
+		goto NS_ERROR;
+
+	tout.tv_sec = SEND_TIMEOUT;
+	if (setsockopt(listen_fd, SOL_SOCKET, SO_SNDTIMEO, &tout, sizeof(tout)) < 0)
+		goto NS_ERROR;
+
+	int reuse = 1;
+	if (setsockopt(listen_fd, SOL_SOCKET, SO_REUSEPORT, &reuse, sizeof(reuse)) < 0)
+		goto NS_ERROR;
+
+	struct sockaddr_in serv_addr;
+	serv_addr.sin_family = AF_INET;
+	serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);
+	serv_addr.sin_port = htons(port);
+
+	if (bind(listen_fd, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0)
+		goto NS_ERROR;
+
+	if (listen(listen_fd, 0) < 0)
+		goto NS_ERROR;
+
+	return listen_fd;
+
+NS_ERROR:
+	close(listen_fd);
+	return -1;
+}
+
+char *rand_string(void) {
+	char abc[] = "asdfghjklzxcvbnmqwertyuiopQWERTYUIOPASDFGHJKLZXCVBNM1234567890";
+	char *res = malloc(name_len + 1);
+	if (res == NULL)
+		return NULL;
+
+	for (int i = 0; i < name_len; i++)
+		res[i] = abc[rand() % (sizeof(abc) - 1)];
+
+	res[name_len] = '\0';
+	return res;
+}
+
+char *rand_name(void) {
+	while (1) {
+		char *filename = rand_string();
+		if (filename == NULL)
+			continue;
+
+		struct stat sb;
+		if (stat(filename, &sb) < 0)
+			return filename;
+
+		free(filename);
+	}
+}
+
+int send_str(int fd, const char *str, ssize_t size, int flag) {
+	ssize_t n = 0;
+	ssize_t rbytes = size;
+
+	while (rbytes) {
+		ssize_t ret = 0;
+		if (flag)
+			ret = send(fd, str + n, rbytes, 0);
+
+		else
+			ret = write(fd, str + n, rbytes);
+
+		if (ret < 0 && (errno != EAGAIN || errno != EINTR))
+			return 1;
+
+		else if (ret == 0)
+			return 0;
+
+		rbytes -= ret;
+		n += size - rbytes;
+	}
+
+	return 0;
+}
+
+void upload(int cfd, pid_t par) {
+	int ret = -1;
+	int ffd = 0;
+
+	char *filename = rand_name();
+	if (send(cfd, filename, strlen(filename), 0) < 0)
+		goto UPL_ERROR;
+
+	if (send(cfd, "\n", 1, 0) < 0)
+		goto UPL_ERROR;
+
+	ffd = open(filename, O_CREAT | O_WRONLY, 0666);
+	if (ffd < 0)
+		goto UPL_ERROR;
+
+	char buf[BUFLEN + 1];
+
+	ssize_t tbytes = 0;
+	while (1) {
+		ssize_t rbytes = recv(cfd, buf, sizeof(buf), 0);
+		if (rbytes < 0 && (errno != EAGAIN || errno != EINTR))
+			goto UPL_ERROR;
+
+		else if (rbytes == 0)
+			break;
+
+		tbytes += rbytes;
+		if (tbytes / 1024 / 1024 >= max_size) {
+			send_str(cfd, MSG2, sizeof(MSG2), WRITE);
+			break;
+		}
+
+		if (send_str(ffd, buf, rbytes, WRITE))
+			goto UPL_ERROR;
+	}
+
+	ret = 0;
+
+UPL_ERROR:
+	if (ffd > 0)
+		close(ffd);
+
+	send_str(cfd, MSG3, sizeof(MSG3), WRITE);
+	close(cfd);
+	if (ret == -1)
+		fprintf(stderr, "%s: input thread: %s: %s\n", prog_name, filename, strerror(errno));
+
+	free(filename);
+	kill(par, SIGUSR1);
+	exit(0);
+}
+
+void load(int cfd, pid_t par) {
+	int ret = -1;
+	int ffd = 0;
+
+	/* Get filename */
+	char *filename = malloc(name_len + 1);
+	if (filename == NULL)
+		goto LD_ERROR;
+
+	ssize_t rbytes = recv(cfd, filename, name_len, 0);
+	if (rbytes <= 0) {
+		if (rbytes == 0)
+			ret = 0;
+
+		goto LD_ERROR;
+	}
+
+	filename[rbytes] = '\0';
+	char *ptr = strchr(filename, '\n');
+	if (ptr)
+		*ptr = '\0';
+
+	if (strstr(filename, ".") || strstr(filename, "/"))
+		goto LD_ERROR;
+
+	/* INFO */
+	if (!strcmp(filename, "INFO")) {
+		char msg[64];
+		int ret2 = snprintf(msg, sizeof(msg), "Max file size: %zuMB\nMax clients in thread: %zu\n", max_size, max_clients);
+
+		if (send_str(cfd, msg, (ssize_t)ret2, SEND))
+			goto LD_ERROR;
+
+		ret = 0;
+		goto LD_ERROR;
+	}
+
+	/* Open and send */
+	ffd = open(filename, O_RDONLY);
+	if (ffd < 0) {
+		send_str(cfd, MSG4, sizeof(MSG4), SEND);
+		goto LD_ERROR;
+	}
+
+	char buf[BUFLEN + 1];
+	while (1) {
+		rbytes = read(ffd, buf, sizeof(buf));
+		if (rbytes < 0 && (errno != EAGAIN || errno != EINTR))
+			goto LD_ERROR;
+
+		else if (rbytes == 0)
+			break;
+
+		if (send_str(cfd, buf, rbytes, SEND))
+			goto LD_ERROR;
+	}
+
+	ret = 0;
+
+LD_ERROR:
+	if (ffd > 0)
+		close(ffd);
+
+	close(cfd);
+	if (ret == -1)
+		fprintf(stderr, "%s: output thread: %s: %s\n", prog_name, filename, strerror(errno));
+
+	free(filename);
+	kill(par, SIGUSR2);
+	exit(0);
+}
+
+void sig_handler(int sig) {
+	if (sig == SIGUSR1)
+		ifd_clients--;
+
+	else if (sig == SIGUSR2)
+		ofd_clients--;
+
+	else {
+		close(ifd);
+		close(ofd);
+
+		exit(0);
+	}
+}
+
+void Proc(int fd, int flag) {
+	static struct sockaddr_in cli_addr;
+	socklen_t length = sizeof(cli_addr);
+
+	pid_t par = getpid();
+
+	while (1) {
+		int cfd = accept(fd, (struct sockaddr *)&cli_addr, &length);
+		if (cfd < 0)
+			continue;
+
+		if (flag == INPUT && ifd_clients < max_clients) {
+			ifd_clients++;
+
+			if (fork() == 0) {
+				close(fd);
+				upload(cfd, par);
+			}
+		}
+
+		else if (flag == OUTPUT && ofd_clients < max_clients) {
+			ofd_clients++;
+
+			if (fork() == 0) {
+				close(fd);
+				load(cfd, par);
+			}
+		}
+
+		else {
+			send(cfd, MSG1, sizeof(MSG1), 0);
+			close(cfd);
+		}
+	}
+}
+
+int main(int argc, char **argv) {
+	srand(time(NULL));
+	prog_name = argv[0];
+
+	signal(SIGUSR1, sig_handler);
+	signal(SIGUSR2, sig_handler);
+	signal(SIGINT, sig_handler);
+	signal(SIGTERM, sig_handler);
+	signal(SIGCHLD, SIG_IGN);
+
+	int opt;
+	while ((opt = getopt(argc, argv, "i:o:m:d:s:n:")) != -1) {
+		switch (opt) {
+			case 'i':
+				iport = atoi(optarg);
+				break;
+
+			case 'o':
+				oport = atoi(optarg);
+				break;
+
+			case 'm':
+				sscanf(optarg, "%zu", &max_clients);
+				break;
+
+			case 'd':
+				dir = optarg;
+				break;
+
+			case 's':
+				sscanf(optarg, "%zu", &max_size);
+				break;
+
+			case 'n':
+				sscanf(optarg, "%zu", &name_len);
+				break;
+
+			default:
+				printf("%s [iomds] - Simple file sharing server\n\t-i NUM Input port\tdefault: %d\n\t-o NUM Output port\tdefault: %d\n\t-m NUM Max clients\tdefault: %zu\n\t-d DIR Word directory\tdefault: %s\n\t-s NUM Max file size\tdefault: %zuMB\n\t-n NUM Filename length\tdefault: %zu\n", prog_name, iport, oport, max_clients, dir, max_size, name_len);
+				return 0;
+		}
+	}
+
+	if (chdir(dir) < 0) {
+		fprintf(stderr, "%s: chdir: %s\n", prog_name, strerror(errno));
+		return 1;
+	}
+
+	ifd = new_server(iport);
+	if (ifd == -1) {
+		fprintf(stderr, "%s: new_server: input socket: %s\n", prog_name, strerror(errno));
+		return 1;
+	}
+
+	ofd = new_server(oport);
+	if (ofd == -1) {
+		fprintf(stderr, "%s: new_server: output socket: %s\n", prog_name, strerror(errno));
+		return 1;
+	}
+
+	if (fork() == 0)
+		Proc(ofd, OUTPUT);
+
+	else
+		Proc(ifd, INPUT);
+}