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client.c
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client.c
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#include <stdio.h>
#include <stdlib.h>
#include <netdb.h>
#include <netinet/in.h>
#include <string.h>
#include <pthread.h>
#include <unistd.h>
#include <sys/stat.h>
#define SIZE_FILE_MAX 104857600
#define PACKET_SIZE 1024
/*
Because our chat system does not strictly follow a send/response protocol
We need to have a millisecond delay in order to avoid multiple messages from
being sent into a single buffer to the server.
*/
struct timespec ts;
int friend_fd = 0;
char friend_nick [PACKET_SIZE];
int receivingFile = 0;
FILE *file;
int transfer_file(int socket_fd, char* filename)
{
char packaged[PACKET_SIZE];
char buffer[PACKET_SIZE-5];
FILE *fp;
fp = fopen(filename, "rb");
if(fp == NULL)
{ perror("Error opening file"); return 1; }
while(1)
{
bzero(packaged, PACKET_SIZE);
bzero(buffer, PACKET_SIZE-5);
int nread = fread(buffer, 1, PACKET_SIZE-5, fp);
if(nread > 0)
{
//printf("BUFFERING:%s\n", buffer);
//sprintf(packaged, "%04d%s", friend_fd, buffer);
//printf("SENDING: %s\n", buffer);
write(socket_fd, buffer, strlen(buffer));
nanosleep(&ts, NULL);
}
if (nread < PACKET_SIZE-5)
{
if (feof(fp))
{
bzero(packaged, PACKET_SIZE);
bzero(buffer, PACKET_SIZE-5);
//sprintf(packaged, "%04d", friend_fd);
sprintf(buffer, "/ENDF");
strcat(packaged, buffer);
write(socket_fd, packaged, strlen(packaged));
nanosleep(&ts, NULL);
printf("End of file\n");
return 0;
}
if (ferror(fp))
{
perror("Error reading\n");
// TODO better handling. Should send special message?
return 1;
}
else
{
perror("Unknown error.");
return 2;
}
printf("File transferred.");
break;
}
}
}
void *read_chat(void *socket)
{
int n;
char chat_buffer[PACKET_SIZE];
int * socket_fd = (int *)socket;
while(1){
//read server response
bzero(chat_buffer, PACKET_SIZE);
n = read((* socket_fd), chat_buffer, PACKET_SIZE-1);
//printf("RECEIVED: %s\n", chat_buffer);
if(n < 0){
sleep(1); //sleep some time while waiting for a message
} else {
//display message
//if(strlen(chat_buffer) < 2){
if(friend_fd == 0 && strchr(chat_buffer, '|') != NULL){
int index = strchr(chat_buffer, '|') - chat_buffer + 1;
char fd_id [5];
char stripped_message [PACKET_SIZE-5];
memcpy(fd_id, &chat_buffer[0], n);
memcpy(stripped_message, &chat_buffer[index], n - index);
fd_id[index] = '\0';
friend_fd = atoi(fd_id);
strcpy(friend_nick, stripped_message);
// friend_nick = stripped_message;
printf("You are chatting with %s\n", stripped_message);
}
else if (strstr(chat_buffer, "/ENDF") != NULL){
receivingFile = 0;
fclose(file);
printf("File transfer Complete\n");
}
else if(receivingFile == 1)
{
//printf("rcvd chunk %s\n", chat_buffer);
fwrite(chat_buffer, 1, n, file);
nanosleep(&ts, NULL);
}
else if (strstr(chat_buffer, "/ERR") != NULL)
{
printf("%s\n", &chat_buffer[4]);
printf("The client will now close.\n");
exit(0);
}
// Chatroom was closed
else if (strstr(chat_buffer, "/PART") != NULL)
{
friend_fd = 0;
memset(friend_nick,0,sizeof(friend_nick));
printf("%s\n", &chat_buffer[5]);
}
// Hack to prevent triggering file creation, should compare indices of strings
else if (strstr(chat_buffer, "/HELP") != NULL)
{
printf("%s: %s\n", friend_nick, chat_buffer);
}
else if (strstr(chat_buffer, "/FILE") != NULL)
{
char* filename = strrchr(chat_buffer, '/');
filename++;
receivingFile = 1;
file = fopen(filename, "w+b");
printf("created file\n");
}
else
{
if(strlen(chat_buffer) == 0)
{
printf("The server is no longer available. Closing client.\n");
if(receivingFile)
fclose(file);
exit(0);
}
printf("%s: %s\n", friend_nick, chat_buffer);
}
}
}
}
int main(int argc, char *argv[]){
ts.tv_sec = 100 / 1000;
ts.tv_nsec = (1 % 1000) * 1000000;
int socket_fd, n;
char packaged[PACKET_SIZE];
char buffer[PACKET_SIZE-5];
//not given hostname and port
if(argc <3){
fprintf(stderr, "usage %s hostname port\n", argv[0]);
exit(0);
}
//init socket
socket_fd = socket(AF_INET, SOCK_STREAM, 0);
if(socket_fd < 0){
perror("Error opening socket");
exit(1);
}
struct addrinfo hints, *servinfo, *p;
int rv;
memset(&hints, 0, sizeof hints);
hints.ai_family = AF_UNSPEC; // use AF_INET6 to force IPv6
hints.ai_socktype = SOCK_STREAM;
if ((rv = getaddrinfo(argv[1], argv[2], &hints, &servinfo)) != 0)
{
fprintf(stderr, "getaddrinfo: %s\n", gai_strerror(rv));
exit(1);
}
// loop through all the results and connect to the first we can
for(p = servinfo; p != NULL; p = p->ai_next)
{
if ((socket_fd = socket(p->ai_family, p->ai_socktype,
p->ai_protocol)) == -1)
{
perror("socket");
continue;
}
if (connect(socket_fd, p->ai_addr, p->ai_addrlen) == -1)
{
close(socket_fd);
//perror("connect");
continue;
}
break; // if we get here, we must have connected successfully
}
// Identifying Connect command
printf("Please enter your nickname: ");
//create message for server
bzero(packaged, PACKET_SIZE-1);
bzero(buffer, PACKET_SIZE-5);
fgets(buffer, PACKET_SIZE-5, stdin);
buffer[strcspn(buffer, "\r\n")] = 0; // Trim newlines
sprintf(packaged, "/CONN");
strcat(packaged, buffer);
//send message to server
n = write(socket_fd, packaged, strlen(packaged));
if(n < 0)
{ perror("Error identifying to server"); exit(1); }
pthread_t reader_thread;
if(pthread_create(&reader_thread, NULL, read_chat, &socket_fd)){
fprintf(stderr, "Error creating reader thread\n");
exit(1);
}
printf("Please enter your messages: ");
while(1){
//create message for server
bzero(packaged, PACKET_SIZE-1);
bzero(buffer, PACKET_SIZE-5);
fgets(buffer, PACKET_SIZE-6, stdin);
buffer[strcspn(buffer, "\r\n")] = 0; // Trim newlines
//sprintf(packaged, "%04d", friend_fd);
// Check if file-transfer has started.
if(strstr(buffer, "/FILE") == buffer)
{
if(friend_fd == 0)
{
printf("Cannot send file while in queue.\n");
continue;
}
buffer[strcspn(buffer, "\r\n")] = 0; // Trim newlines
char filename [PACKET_SIZE-12];
memcpy(filename, &buffer[6], PACKET_SIZE-12);
int size;
struct stat st;
stat(filename, &st);
size = st.st_size;
if(size > SIZE_FILE_MAX)
{
printf("File size exceeded.");
continue;
}
strcat(packaged, "/FILE/");
strcat(packaged, filename);
FILE *fp;
fp = fopen(filename, "rb");
if(fp == NULL)
{
perror("Error opening file");
}
else
{
//send message to server
n = write(socket_fd, packaged, strlen(packaged));
nanosleep(&ts, NULL);
if(n < 0)
{ perror("Error writing to server"); continue; }
transfer_file(socket_fd, filename);
}
}
// Majority case
else
{
//strcat(packaged, buffer);
//send message to server
n = write(socket_fd, buffer, strlen(buffer));
nanosleep(&ts, NULL);
if(n < 0)
{ perror("Error writing to server"); exit(1); }
}
}
close(socket_fd);
}