// Include the most common headers from the C standard library #include <string.h> #include <stdio.h> #include <sys/socket.h> #include <arpa/inet.h> #include <sys/errno.h> #include <unistd.h> // Include the main libnx system header, for Switch development #include <switch.h> // This example shows how to use lp2p, for Switch-hosted local-network communications with mainly non-Switch devices. See also libnx lp2p.h. // Note that in an actual app you may want to use lp2p/sockets from another thread. Result create_network(const Lp2pGroupInfo *in_group_info) { Result rc=0; rc = lp2pCreateGroup(in_group_info); printf("lp2pCreateGroup(): 0x%x\n", rc); return rc; } void leave_network(void) { Result rc=0; u32 tmp32=0; rc = lp2pLeave(&tmp32); printf("lp2pLeave(): 0x%x, 0x%x\n", rc, tmp32); rc = lp2pDestroyGroup(); printf("lp2pDestroyGroup(): 0x%x\n", rc); } void generate_random_str(char *str, size_t string_len) { if (string_len & 1) string_len--; for (size_t i=0; i<string_len; i+=2) { u8 tmp=0; randomGet(&tmp, sizeof(tmp)); snprintf(&str[i], 3, "%02X", tmp); } } int main(int argc, char **argv) { // This example uses a text console, as a simple way to output text to the screen. // If you want to write a software-rendered graphics application, // take a look at the graphics/simplegfx example, which uses the libnx Framebuffer API instead. // If on the other hand you want to write an OpenGL based application, // take a look at the graphics/opengl set of examples, which uses EGL instead. consoleInit(NULL); // Configure our supported input layout: a single player with standard controller styles padConfigureInput(1, HidNpadStyleSet_NpadStandard); // Initialize the default gamepad (which reads handheld mode inputs as well as the first connected controller) PadState pad; padInitializeDefault(&pad); // Initialise sockets socketInitializeDefault(); printf("lp2p example\n"); int sockfd=-1; struct sockaddr_in serv_addr; Result rc=0; Lp2pIpConfig ip_config={0}; Lp2pGroupInfo in_group_info={0}; Lp2pGroupInfo group_info={0}; lp2pCreateGroupInfo(&in_group_info); // This example uses [11.0.0+] WPA2-PSK. If you want to use Nintendo-encryption for the network (for communicating with accessories such as mklive), use flags=1 (which is also the default), and replace the lp2pGroupInfoSetPassphrase call with lp2pGroupInfoSetPresharedKey. // If you want to use plaintext (open network), set in_group_info.security_type manually, and call lp2pGroupInfoSetPresharedKey (where the used keydata doesn't matter). s8 flags=0; lp2pGroupInfoSetFlags(&in_group_info, &flags, 1); // See lp2p.h Lp2pGroupInfo::service_name. char ssid[0x20] = {"libnxlp2p-"}; char passphrase[0x40] = {0}; generate_random_str(&ssid[strlen(ssid)], 8); generate_random_str(passphrase, 16); lp2pGroupInfoSetServiceName(&in_group_info, ssid); lp2pGroupInfoSetPassphrase(&in_group_info, passphrase); rc = lp2pInitialize(Lp2pServiceType_App); printf("lp2pInitialize(): 0x%x\n", rc); if (R_SUCCEEDED(rc)) { printf("Press A to create a network.\n"); printf("Press X to leave a network.\n"); printf("Press the D-Pad buttons while on a network to send messages.\n"); } printf("Press + to exit.\n"); // Main loop while(appletMainLoop()) { // Scan the gamepad. This should be done once for each frame padUpdate(&pad); // padGetButtonsDown returns the set of buttons that have been newly pressed in this frame compared to the previous one u32 kDown = padGetButtonsDown(&pad); if (kDown & HidNpadButton_Plus) break; // break in order to return to hbmenu if (R_SUCCEEDED(rc) && (kDown & HidNpadButton_A)) { Result rc2 = create_network(&in_group_info); printf("create_network(): 0x%x\n", rc2); // We didn't set the full ServiceName, so the sysmodule will generate the rest of it. Use lp2pGetGroupInfo to get the actual ServiceName. if (R_SUCCEEDED(rc2)) { rc2 = lp2pGetGroupInfo(&group_info); printf("lp2pGetGroupInfo(): 0x%x\n", rc2); } if (R_SUCCEEDED(rc2)) { rc2 = lp2pGetIpConfig(&ip_config); printf("lp2pGetIpConfig(): 0x%x\n", rc2); } if (R_SUCCEEDED(rc2)) { printf("Network created.\nSSID: %s\nPassphrase: %s\n", group_info.service_name, passphrase); } // Once on a network, you can use whatever sockets you want. In this example, we'll send/recv data with UDP-broadcast. if (R_SUCCEEDED(rc2)) { sockfd = socket(AF_INET, SOCK_DGRAM, 0); if (sockfd < 0) { printf("socket() failed\n"); } else { int ret=0; int optval = 1; ret = setsockopt(sockfd, SOL_SOCKET, SO_BROADCAST, (char *)&optval, sizeof(optval)); if (ret==-1) { printf("setsockopt() failed\n"); close(sockfd); sockfd = -1; } // Setup a broadcast addr. If you want to use IP addrs for members on the network, see lp2pGetMembers(). if (sockfd >= 0) { memset(&serv_addr, 0, sizeof(serv_addr)); serv_addr.sin_family = AF_INET; serv_addr.sin_addr.s_addr = htonl(ntohl(((struct sockaddr_in*)ip_config.ip_addr)->sin_addr.s_addr) | ~ntohl(((struct sockaddr_in*)ip_config.subnet_mask)->sin_addr.s_addr)); serv_addr.sin_port = htons(7777); if (bind(sockfd, (struct sockaddr*) &serv_addr, sizeof(serv_addr)) < 0) { printf("bind failed\n"); close(sockfd); sockfd = -1; } } } } } if (R_SUCCEEDED(rc) && (kDown & HidNpadButton_X)) { if (sockfd >= 0) { close(sockfd); sockfd = -1; } leave_network(); } if (R_SUCCEEDED(rc) && sockfd>=0 && (kDown & (HidNpadButton_Left|HidNpadButton_Right|HidNpadButton_Up|HidNpadButton_Down))) { char tmpstr[32]; memset(tmpstr, 0, sizeof(tmpstr)); if (kDown & HidNpadButton_Left) strncpy(tmpstr, "Button Left pressed.", sizeof(tmpstr)-1); else if (kDown & HidNpadButton_Right) strncpy(tmpstr, "Button Right pressed.", sizeof(tmpstr)-1); else if (kDown & HidNpadButton_Up) strncpy(tmpstr, "Button Up pressed.", sizeof(tmpstr)-1); else if (kDown & HidNpadButton_Down) strncpy(tmpstr, "Button Down pressed.", sizeof(tmpstr)-1); ssize_t ret = sendto(sockfd, tmpstr, sizeof(tmpstr), 0, (struct sockaddr*) &serv_addr, sizeof(struct sockaddr_in)); int tmp = errno; printf("sendto(): %ld", ret); if (ret < 0) printf(", %s", strerror(tmp)); printf("\n"); } if (R_SUCCEEDED(rc) && sockfd>=0) { char tmpstr[32]; memset(tmpstr, 0, sizeof(tmpstr)); struct sockaddr_in src_addr={0}; socklen_t fromlen = sizeof(struct sockaddr_in); ssize_t ret = recvfrom(sockfd, tmpstr, sizeof(tmpstr), MSG_DONTWAIT, (struct sockaddr*) &src_addr, &fromlen); tmpstr[sizeof(tmpstr)-1] = 0; if (ret>0) printf("Received data: %s\n", tmpstr); } consoleUpdate(NULL); } if (sockfd >= 0) { close(sockfd); sockfd = -1; } leave_network(); lp2pExit(); socketExit(); consoleExit(NULL); return 0; }