path: root/client.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <netdb.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <ctype.h>
#include <pthread.h>

#include <arpa/inet.h>

#include "protocol.c"

#define MAXDATASIZE 100 // max number of bytes we can get at once 

#define MAX_READ_SIZE 1024
#define LINE_MAX 1024

void *command_line_routine(void *args);

int handle_handshake(int sockfd, char* udpPort);

int station_is_set = 0;
int l = 0;
int waiting = 0;
int exiting = 0;

// get sockaddr, IPv4 or IPv6:
void *get_in_addr(struct sockaddr *sa)
{
    if (sa->sa_family == AF_INET) {
        return &(((struct sockaddr_in*)sa)->sin_addr);
    }

    return &(((struct sockaddr_in6*)sa)->sin6_addr);
}

int main(int argc, char *argv[])
{
    int sockfd, numbytesrecv, numbytessent, recvbytes;  
    // char buf[MAXDATASIZE];
    struct addrinfo hints, *servinfo, *p;
    int rv;
    char s[INET6_ADDRSTRLEN];

    if (argc != 4) {
        fprintf(stderr,"<server IP> <server port> <listener port>\n");
        exit(1);
    }

    memset(&hints, 0, sizeof hints);
    hints.ai_family = AF_INET; // only IPv4
    hints.ai_socktype = SOCK_STREAM;

    char* tcpPort = argv[2]; // port we use to connect to server's tcp stream
    char* udpPort = argv[3]; // port we use to connect to server's udp info and command

    if ((rv = getaddrinfo(argv[1], tcpPort, &hints, &servinfo)) != 0) {
        fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
        return 1;
    }

    // loop through all the results and connect to the first we can
    for(p = servinfo; p != NULL; p = p->ai_next) {
        if ((sockfd = socket(p->ai_family, p->ai_socktype,
                p->ai_protocol)) == -1) {
            perror("client: socket");
            continue;
        }

        if (connect(sockfd, p->ai_addr, p->ai_addrlen) == -1) {
            close(sockfd);
            perror("client: connect");
            continue;
        }

        break;
    }

    if (p == NULL) {
        fprintf(stderr, "client: failed to connect\n");
        return 2;
    }

    inet_ntop(p->ai_family, get_in_addr((struct sockaddr *)p->ai_addr),
            s, sizeof s);
    // printf("client: connecting to %s\n", s);

    freeaddrinfo(servinfo); // all done with this structure

    uint16_t num_stations = handle_handshake(sockfd, udpPort);

    fflush(stdout);
    printf("Welcome to Snowcast! The server has %u stations.\n", num_stations);
    fflush(stdout);

    pthread_t command_line_thread;
    pthread_create(&command_line_thread, NULL, command_line_routine, (void*)sockfd);

    // CONSIDER: could recieve the welcome message here
    // int recvbytes;
    while (1) {
        // recv the first byte of the message to get it's type
        uint8_t reply_type = -1;
        // print size of utin8
        if (recv(sockfd, &reply_type, 1, 0) == -1) {
            if (exiting) {
                break;
            }
            perror("recv in first byte");
            exit(1);
        }

        if (reply_type == 2) { // we have a second welcome message
            fprintf(stderr, "WECLOME reply received twice. Exiting.\n");
            close(sockfd);
            exit(1);
        }

        if (reply_type == 3) { // we have an announce message

            if (!station_is_set) {
                fprintf(stderr, "ANNOUNCE reply received before SETSTATION command. Exiting.\n");
                close(sockfd);
                exit(1);
            }

            // get the string size
            u_int8_t string_size = -1;
            if (recv(sockfd, &string_size, 1, 0) == -1) {
                perror("recv in announce");
                exit(1);
            }
            char *song_name = malloc(string_size);
            if(song_name == NULL) { perror("malloc in song name"); }
            
            int bytes_to_read = string_size;
            if (recv_all(sockfd, song_name, &bytes_to_read) == -1) {
                perror("recv_all in announce");
                exit(1);
            }

            if (!waiting) printf("\n"); // note: this is worth the lines for a clean cmd prompt
            waiting = 0;
            fflush(stdout);
            printf("New song announced: %s\n", song_name);
            printf("snowcast_control> ");
            fflush(stdout);
            free(song_name);
            continue;
        } else if (reply_type == 4) { // we have an invalid command message
            // get the string size
            u_int8_t string_size = -1;
            if (recv(sockfd, &string_size, 1, 0) == -1) {
                perror("recv in invalid");
                exit(1);
            }
            char *message = malloc(string_size);
            if(message == NULL) { perror("malloc in message"); }
            int bytes_to_read = string_size;
            if (recv_all(sockfd, message, &bytes_to_read) == -1) {
                perror("recv_all in invalid");
                exit(1);
            }
            fflush(stdout);
            printf("received INVALID reply: %s.\nExiting.\n", message);
            fflush(stdout);
            free(message);
            close(sockfd);
            exit(1);
        }
        else if (reply_type == 6) { // we are getting STATIONINFO
            // get the string size
            uint32_t buf_string_size = -1;
            int bytes_to_read = sizeof(uint32_t);
            if (recv_all(sockfd, &buf_string_size, &bytes_to_read) == -1) {
                perror("recv_all 1 in stationinfo");
                exit(1);
            }

            uint32_t string_size = ntohl(buf_string_size);
            printf("string size: %d\n", string_size);
            char *info = malloc(string_size);
            if(info == NULL) { perror("malloc in info"); }
            bytes_to_read = string_size;
            if (recv_all(sockfd, info, &bytes_to_read) == -1) {
                perror("recv_all 2 in stationinfo");
                exit(1);
            }
            remove_timeout(sockfd);
            if (l) printf("received STATIONINFO reply.\n");

            fflush(stdout);
            printf("Station Information:\n%s\n", info);
            printf("snowcast_control> ");
            fflush(stdout);

            free(info);
            continue;
        }
        else if (reply_type == 7) { // we are getting StationShutdown
            if (l) printf("received STATIONSHUTDOWN reply.\n");
            if (!waiting) printf("\n"); // note: this is worth the lines for a clean cmd prompt
            waiting = 0;
            remove_timeout(sockfd);
            fflush(stdout);
            printf("This station has shut down. Please select a different station.\n");
            printf("snowcast_control> ");
            fflush(stdout);
            continue;
        }
        else if (reply_type == 8) { // we are getting NewStation
            uint16_t station_number = -1;
            if (recv(sockfd, &station_number, 2, 0) == -1) {
                perror("recv in new station");
                exit(1);
            }
            station_number = ntohs(station_number);
            if (l) printf("received NEWSTATION reply.\n");
            fflush(stdout);
            printf("\nThere is now a new station @ index %d.\n", station_number);
            printf("snowcast_control> ");
            fflush(stdout);
            continue;
        }

        printf("\nsocket to server HUNGUP. Exiting.\n");
        close(sockfd);
        exit(1);
    }
    return 0;
}

void *command_line_routine(void* args) {
    int sockfd = (int) args;

    char input[LINE_MAX];

    printf("Enter a number to change to it's station. Enter q to end stream.\n");
    printf("snowcast_control> ");
    fflush(stdout);
    while (1) {
	    char *line = fgets(input, LINE_MAX, stdin);

        if (line == NULL) {
            continue;
        } else if (strncmp("q\n", input, LINE_MAX) == 0) {
            // end code if type in q
            exiting = 1;
            printf("Exiting.\n");
            close(sockfd);
            exit(0);
        } else if (strncmp("l\n", input, LINE_MAX) == 0) {
            // send the command to list stations
            if (l) printf("sending LISTSTATIONS command. waiting for STATIONINFO reply.\n");
            apply_timeout(sockfd);
            int list_station_reply_type = 5;
            if (send(sockfd, &list_station_reply_type, 1, 0) == -1) {
                perror("send");
                exit(1);
            }
        } else if (strncmp("log\n", input, LINE_MAX) == 0) {
            l = !l;
            printf("LOGGING is now %s!\n", l ? "on" : "off");
            printf("snowcast_control> ");
            fflush(stdout);
        }
        else {
            // convert input to an int
            int inputInt = atoi(input);
            if (input[0] != '0'  && inputInt == 0) {
                printf("unknown command: %s\n", input);
                printf("snowcast_control> ");
                fflush(stdout);
                continue;
            }
            // printf("Changing to station %d.\n", inputInt);

            // set waiting so no new line on announce
            waiting = 1;
            // send the command to change the station
            apply_timeout(sockfd);
            struct SetStation setStation;
            setStation.commandType = 1;
            setStation.stationNumber = htons(inputInt);
            int bytes_to_send = sizeof(struct SetStation);
            // apply_timeout(sockfd);
            if (send_all(sockfd, &setStation, &bytes_to_send) == -1) {
                perror("send_all");
                exit(1);
            }
            if (!station_is_set) {
                station_is_set = 1;
            }
        }
    }
    return (NULL);
}

int handle_handshake(int sockfd, char* udp_port) {
    apply_timeout(sockfd);

    if (l) printf("found server, sending HELLO command. waiting for ANNOUNCE reply.\n");

    struct Hello hello;
    hello.commandType = 0;
    // convert updPort to an int
    int udp_port_int = atoi(udp_port);
    hello.udpPort = htons(udp_port_int);
    if (send(sockfd, &hello, sizeof(struct Hello), 0) == -1) {
        perror("send");
        exit(1);
    }

     // recv the first byte of the message to get it's type
    uint8_t reply_type = -1;
    // print size of utin8
    if (recv(sockfd, &reply_type, 1, 0) == -1) {
        perror("recv in handshake");
        exit(1);
    }

    // recv the message, check for errors too
    int16_t num_stations = -1;
    int bytes_to_read = sizeof(uint16_t);
    if (recv_all(sockfd, &num_stations, &bytes_to_read) == -1) {
        perror("recv_all in handshake");
        exit(1);
    }

    if (l) printf("received ANNOUNCE reply.\n");

    remove_timeout(sockfd);

    return ntohs(num_stations);
}