C socket: recv jams the program if used twice - c

Question

I'm trying to implement C code on a UNIX platform which sends all files data to the client, and uploading a file from the client to the server.
The first part is working but for the second part I've encountered an issue.
After some debugging I've found out that the server side jams the client when I'm using recv the second time in the code [I've marked it for your convenience].
I've tried to look up on guides or what I'm doing wrong but I couldn't find the issue for what causing the program to get stuck.
For de-bugging purposes I'm now trying to send an int from client to the server
server side
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/stat.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <sys/wait.h>
#include <dirent.h>
#include <fcntl.h>
#define PORT 0x0da2
#define IP_ADDR 0x7f000001
#define QUEUE_LEN 20
int main(void)
{
//char directory[1024];
//chdir("server");
//getcwd(directory, sizeof(directory));
//printf("%s",directory);
DIR* directory;
struct dirent* ent;
int fd;
char buffer[1000] = {0};
char convert[100] = {0};
size_t array_size = 0;
struct stat fileStat;
if ((directory = opendir ("server")) == NULL)
{
perror ("Cannot open .");
return 1;
}
while ((ent = readdir(directory)) != NULL)
{
if (!( !strcmp(ent->d_name, ".") || !strcmp(ent->d_name, "..")) )
{
fd = openat(dirfd(directory), ent->d_name, 0);
if (fd == -1)
{
perror ("Can't get stats.");
return 1;
}
if(fstat(fd, &fileStat)== -1)
{
perror ("Can't get stats.");
return 1;
}
strcat(buffer,ent->d_name);
sprintf(convert,"%lld", (long long) fileStat.st_size);
strcat(buffer, " ");
strcat(buffer,convert);
strcat(buffer,"\n");
}
}
int listenS = socket(AF_INET, SOCK_STREAM, 0);
if (listenS < 0)
{
perror("socket");
return 1;
}
struct sockaddr_in s = {0};
s.sin_family = AF_INET;
s.sin_port = htons(PORT);
s.sin_addr.s_addr = htonl(IP_ADDR);
if (bind(listenS, (struct sockaddr*)&s, sizeof(s)) < 0)
{
perror("bind");
return 1;
}
if (listen(listenS, QUEUE_LEN) < 0)
{
perror("listen");
return 1;
}
struct sockaddr_in clientIn;
int clientInSize = sizeof clientIn;
while (1)
{
int newfd = accept(listenS, (struct sockaddr*)&clientIn, (socklen_t*)&clientInSize);
if (newfd < 0)
{
perror("accept");
return 1;
}
if (send(newfd, &buffer, strlen(buffer), 0) < 0)
{
perror("send");
return 1;
}
char namebuff[100] = {0};
char sizebuff[256] = {0};
//int size;
ssize_t nrecv;
int error = 0;
int fsize;
//int dataleft;
if ((nrecv = recv(newfd, &namebuff, sizeof(namebuff), 0)) < 0)
{
perror("recv");
return 1;
}
if((strstr(buffer,namebuff) != NULL))
{
error = -1;
if (send(newfd, &error, sizeof(int), 0) < 0)
{
perror("send");
return 1;
}
}
/*if ((nrecv = recv(newfd, &fsize, sizeof(int), 0)) < 0) //this line is what jams the program
{
perror("recv");
return 1;
}*/
if(error != -1) //
{
if ((nrecv = recv(newfd, &sizebuff, sizeof(sizebuff), 0)) < 0)
{
perror("recv");
return 1;
}
fsize = atoi(sizebuff);
}
printf("%s\n",namebuff);
printf("%d\n",fsize);
close(newfd);
}
close(listenS);
return 0;
}
client side
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <sys/stat.h>
#include <netdb.h>
#include <arpa/inet.h>
#include <sys/wait.h>
#include <fcntl.h>
#define PORT 0x0da2
#define IP_ADDR 0x7f000001
int ctoi(char c) {
return c-'0';
}
int main(void)
{
int sock = socket(AF_INET, SOCK_STREAM, 0);
ssize_t nrecv;
struct sockaddr_in s = {0};
s.sin_family = AF_INET;
s.sin_port = htons(PORT);
s.sin_addr.s_addr = htonl(IP_ADDR);
if (connect(sock, (struct sockaddr*)&s, sizeof(s)) < 0)
{
perror("connect");
return 1;
}
printf("Successfully connected.\n");
char buffer[1000] = {0};
if ((nrecv = recv(sock, &buffer, sizeof(buffer), 0)) < 0)
{
perror("recv");
return 1;
}
printf("./client list-files\n%s\n", buffer); //nrcev gives the size of the data is recived
int fd;
//int i;
//ssize_t nwrite, nread;
char sizebuff[256];
struct stat file_stat;
int numcheck = 0;
//char buffer2[4096];
char namebuff[100] = "coolfile.txt";
fd=open("coolfile.txt",O_RDONLY);
if (send(sock, &namebuff, strlen(namebuff), 0) < 0)
{
perror("send");
return 1;
}
/*if ((nrecv = recv(sock, &numcheck, sizeof(int), 0)) < 0)
{
perror("recv");
return 1;
}*/
if (numcheck == -1)
{
printf("file already exists in the server\n");
return 1;
}
if (fstat(fd, &file_stat) < 0)
{
printf("error");
return 1;
}
sprintf(sizebuff, "%ld", file_stat.st_size);
//printf("%s\n",sizebuff);
/*int number = 5;
if(send(sock, &number, sizeof(int), 0) < 0)
{
printf("error");
return 1;
}*/
if(send(sock, &sizebuff, strlen(sizebuff), 0) < 0);
{
printf("error");
return 1;
}
/*
nread = read(fd, buffer2, 4096);
for (i = 0; i < nread; i += nwrite)
{
nwrite = write(sock, buffer2 + i, nread - i);
}
} while (nread != 0);*/
return 0;
}
Thanks for your help!