How to handle TIME_WAIT state

server.c

#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <time.h>
#include <pthread.h>

#define BACKLOG       128     // backlog for listen()
#define DEFAULT_PORT  5000    // default listening port
#define BUF_SIZE      28      // message chunk size

time_t ticks;

typedef struct {
  int client_sock;
} thread_param_t;
thread_param_t *params;       // params structure for pthread

pthread_t thread_id;          // thread id

void error(char *msg) {
  perror(msg);
  exit(EXIT_FAILURE);
}

/**
* thread handler after accept()
*/
void *handle_client(void *params) {
  char msg[BUF_SIZE];
  thread_param_t *p = (thread_param_t *) params;  // thread params

  // clear message buffer
  memset(msg, 0, sizeof(msg));

  ticks = time(NULL);
  snprintf(msg, sizeof(msg), "%.24s\r\n", ctime(&ticks));
  write(p->client_sock, msg, strlen(msg));
  printf("Sent message to Client #%d\n", p->client_sock);

  // wait
  usleep(10);

  // clear message buffer
  memset(msg, 0, sizeof(msg));

  // active close, It will remains in `TIME_WAIT` state.
  if (close(p->client_sock) < 0)
    error("Error: close()");
  free(p);

  return NULL;
}

int main(int argc, char *argv[]) {
  int listenfd = 0, connfd = 0;
  struct sockaddr_in serv_addr;

  // build server's internet addr and initialize
  memset(&serv_addr, '0', sizeof(serv_addr));

  serv_addr.sin_family = AF_INET;                // an internet addr
  serv_addr.sin_addr.s_addr = htonl(INADDR_ANY); // let the system figure out our IP addr
  serv_addr.sin_port = htons(DEFAULT_PORT);      // the port we will listen on

  // create the socket, bind, listen
  if ((listenfd = socket(AF_INET, SOCK_STREAM, 0)) < 0)
    error("Error: socket()");
  if (bind(listenfd, (struct sockaddr *) &serv_addr, sizeof(serv_addr)) < 0)
    error("Error: bind() Not enough privilleges(<1024) or already in use");
  if (listen(listenfd, BACKLOG) < 0)
    error("Error: listen()");

  while (1) {
    connfd = accept(listenfd, (struct sockaddr *) NULL, NULL);

    // memory allocation for `thread_param_t` struct
    params = malloc(sizeof(thread_param_t));
    params->client_sock = connfd;

    // 1 client, 1 thread
    pthread_create(&thread_id, NULL, handle_client, (void *) params);
    pthread_detach(thread_id);
  }
}