towel.blinkenlights.nl switch example

ReadMe.txt

Usage: 

put the telnet.nro and telnet.conf files in the /switch folder

CMakeLists.txt

cmake_minimum_required(VERSION 3.5)
set(CMAKE_C_STANDARD 11)
set(CMAKE_CXX_STANDARD 11)

add_executable(stelenet stelnet.c)
target_link_libraries(stelenet -lnx )

stelnet.c

/*
    SimpleTelnet: a simple telnet client suitable for embedded systems
    Copyright (C) 2013  netblue30@yahoo.com

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <arpa/inet.h>
#include <sys/socket.h>
#include <sys/select.h>
//#include <termios.h>
#include <fcntl.h>
#include <switch.h>
#include <netdb.h>
#include <limits.h>


#define DO 0xfd
#define WONT 0xfc
#define WILL 0xfb
//#define DONT 0xfe
#define CMD 0xff
//#define CMD_ECHO 1
#define CMD_WINDOW_SIZE 31

char ServerIP[255];
char ServerPort[255];
int sock;

void ExitProgram() {
    close(sock);
    gfxExit();
    socketExit();
}

void ReadConfigFile(char *ConfigFileName) {
    FILE *configfile = fopen(ConfigFileName, "r");
    if (configfile == NULL) perror("Error opening file");
    //GetServerIP
    fgets(ServerIP, 255, configfile);

    //GetServerPort
    fgets(ServerPort, 255, configfile);

    //remove the newline chars
    strtok(ServerIP, "\n\r");
    strtok(ServerPort, "\n\r");

    fclose(configfile);
}

//Get Ip of the host and write it to the server
void GetHostIp(char *name, struct sockaddr_in *in) {
    struct hostent *he;
    struct in_addr **addr_list;
    // get the host info
    if ((he = gethostbyname(name)) == NULL) {
        herror("gethostbyname");
        sleep(5);
        exit(0);
    } else {
        // print information about this host:
        printf("Official name is: %s\n", he->h_name);
        printf("    IP addresses: ");
        addr_list = (struct in_addr **) he->h_addr_list;
        for (int i = 0; addr_list[i] != NULL; i++) {
            printf("%s ", inet_ntoa(*addr_list[i]));
        }
        printf("\n");
        memcpy(&(in->sin_addr), he->h_addr_list[0], (size_t) he->h_length);
    }
    freehostent(he);
}

void negotiate(int sock, unsigned char *buf, size_t len) {

    if (buf[1] == DO && buf[2] == CMD_WINDOW_SIZE) {
        unsigned char tmp1[10] = {255, 251, 31};
        if (send(sock, tmp1, 3, 0) < 0)
            exit(1);

        unsigned char tmp2[10] = {255, 250, 31, 0, 80, 0, 24, 255, 240};
        if (send(sock, tmp2, 9, 0) < 0)
            exit(1);
        return;
    }

    for (int i = 0; i < len; i++) {
        if (buf[i] == DO)
            buf[i] = WONT;
        else if (buf[i] == WILL)
            buf[i] = DO;
    }

    if (send(sock, buf, len, 0) < 0)
        exit(1);
}

#define BUFLEN 20


int main(int argc, char *argv[]) {
    atexit(ExitProgram);
    gfxInitDefault();
    //Initialize console. Using NULL as the second argument tells the console library to use the internal console structure as current one.
    consoleInit(NULL);
    socketInitializeDefault();
    ReadConfigFile("/switch/telnet.conf");
    struct sockaddr_in server;
    bzero(&server, sizeof(server));

    unsigned char buf[BUFLEN + 1];
    ssize_t len;

    //Create socket
    sock = socket(AF_INET, SOCK_STREAM, 0);
    if (sock == -1) {
        perror("Could not create socket. Error");
        return 0;
    }
    //setup server struct with needed addtesss and resolve host
    server.sin_family = AF_INET;
    server.sin_port = htons((uint16_t) atoi(ServerPort));
    GetHostIp(ServerIP, &server);

    //Connect to remote server
    if (connect(sock, (struct sockaddr *) &server, sizeof(server)) < 0) {
        perror("connect failed. Error");
        return 0;
    }
    puts("Connected...\n");

    // set terminal
    //terminal_set();
    //atexit(terminal_reset);

    struct timeval ts;
    ts.tv_sec = 1; // 1 second
    ts.tv_usec = 0;

    // select setup
    fd_set fds;
    FD_ZERO(&fds);
    if (sock != 0) {
        FD_SET(sock, &fds);
    }
    //FD_SET(0, &fds);

    while (appletMainLoop()) {
        hidScanInput();

        // wait for data
        int nready = select(sock + 1, &fds, 0, 0, &ts);
        if (nready < 0) {
            perror("select. Error");
            break;
        } else if (nready == 0) {
            ts.tv_sec = 1; // 1 second
            ts.tv_usec = 0;
        } else if (sock != 0 && FD_ISSET(sock, &fds)) {
            // start by reading a single byte
            ssize_t rv;
            if ((rv = recv(sock, buf, 1, 0)) < 0)
                break;
            else if (rv == 0) {
                printf("Connection closed by the remote end\n\r");
                break;
            }

            if (buf[0] == CMD) {
                // read 2 more bytes
                len = recv(sock, buf + 1, 2, 0);
                if (len < 0)
                    break;
                else if (len == 0) {
                    printf("Connection closed by the remote end\n\r");
                    break;
                }
                negotiate(sock, buf, 3);
            } else {
                len = 1;
                buf[len] = '\0';
                printf("%s", buf);
                fflush(0);
            }
            //Send Disabled because there is no way to send text input yet
        } /*else if (FD_ISSET(0, &fds)) {
            buf[0] = getc(stdin); //fgets(buf, 1, stdin);
            if (send(sock, buf, 1, 0) < 0)
                break;
            if (buf[0] == '\n') // with the terminal in raw mode we need to force a LF
                putchar('\r');
        }*/

        //hidKeysDown returns information about which buttons have been just pressed (and they weren't in the previous frame)
        u64 kDown = hidKeysDown(CONTROLLER_P1_AUTO);

        if (kDown & KEY_PLUS) break; // break in order to return to hbmenu
        gfxFlushBuffers();
        gfxSwapBuffers();
        gfxWaitForVsync();
    }
    return 0;
}

switchToolchain.cmake

set(DEVKITPRO "/opt/devkitpro")
set(NX 1)

set(CMAKE_SYSTEM_NAME "Generic")
set(CMAKE_C_COMPILER "${DEVKITPRO}/devkitA64/bin/aarch64-none-elf-gcc")
set(CMAKE_CXX_COMPILER "${DEVKITPRO}/devkitA64/bin/aarch64-none-elf-g++")
set(CMAKE_AR "${DEVKITPRO}/devkitA64/bin/aarch64-none-elf-gcc-ar" CACHE STRING "")
set(CMAKE_RANLIB "${DEVKITPRO}/devkitA64/bin/aarch64-none-elf-gcc-ranlib" CACHE STRING "")

set(PKG_CONFIG "${DEVKITPRO}/portlibs/bin/aarch64-none-elf-pkg-config" CACHE STRING "")
set(CPPFLAGS "-D__SWITCH__ -I${DEVKITPRO}/libnx/include -I${DEVKITPRO}/portlibs/switch/include")
set(CMAKE_C_FLAGS "${CPPFLAGS} -march=armv8-a -mtune=cortex-a57 -mtp=soft -fPIC -ffunction-sections" CACHE STRING "C flags")
set(CMAKE_CXX_FLAGS "${CPPFLAGS} ${CMAKE_C_FLAGS} -fno-rtti -fno-exceptions -std=gnu++11" CACHE STRING "C++ flags")

set(CMAKE_FIND_ROOT_PATH ${DEVKITPRO}/devkitA64 ${DEVKITPRO}/libnx ${DEVKITPRO}/portlibs/switch)
set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER)
set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY)
set(CMAKE_FIND_ROOT_PATH_MODE_PACKAGE ONLY)
#set(CMAKE_STATIC_LINKER_FLAGS_INIT "-march=armv8-a -mtune=cortex-a57 -mtp=soft -L${DEVKITPRO}/libnx/lib -L${DEVKITPRO}/portlibs/switch/lib")
set(CMAKE_EXE_LINKER_FLAGS_INIT "-specs=${DEVKITPRO}/libnx/switch.specs -march=armv8-a -mtune=cortex-a57 -mtp=soft -fPIE -L${DEVKITPRO}/libnx/lib -L${DEVKITPRO}/portlibs/switch/lib")

set(BUILD_SHARED_LIBS OFF CACHE INTERNAL "Shared libs not available")
set(CMAKE_INSTALL_PREFIX ${DEVKITPRO}/portlibs/switch)

telnet.conf

towel.blinkenlights.nl
23