printer.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/stat.h>

#include "printer.h"

#define MACDB_FILE  "macdb.csv"
#define MACDB_PATH1 "./"
#define MACDB_PATH2 "/usr/share/snetscan/"
#define RESET       "\033[0m"
#define BOLD        "\033[1m"

char* get_mac_vendor_str(char* file, char* mac) {
  if(file == NULL) return NULL;

  char* vendor;
  char* str = strchr(file, '\n');
  char mac_str[6] = { mac[0] , mac[1], mac[3], mac[4], mac[6], mac[7] };

  /* Search for mac */
  while(str != NULL && strncmp(str + 1, mac_str, 6) != 0)
    str = strchr(str + 1, '\n');

  if(str != NULL) {
    /* We found the mac */
    str++;
    char* tmp1 = str + 7;
    char* tmp2;

    /* If starts with '"', ends with '"' */
    if(*tmp1 == '\"') {
      tmp1++;
      tmp2 = strchr(tmp1, '\"');
    }
    else {
      tmp2 = strchr(tmp1, ',');
    }

    vendor = malloc(sizeof(char)* (tmp2-tmp1 + 1));
    memset(vendor, 0, (tmp2-tmp1 + 1));
    strncpy(vendor, tmp1, tmp2-tmp1);
  }
  else {
    vendor = malloc(sizeof(char)* 4);
    memset(vendor, 0, 4);
    strncpy(vendor, "???", 4);
  }

  return vendor;
}

void print_host(char* file, char* ip_str, char* mac_str, char* vendor, u_int32_t ip, u_int32_t this_host) {
  if(ip == this_host) {
    if(vendor == NULL)
      printf(BOLD "%-18s %-18s" RESET "\n", ip_str, mac_str);
    else
      printf(BOLD "%-18s %-18s(%s)" RESET "\n", ip_str, mac_str, get_mac_vendor_str(file, mac_str));
  }
  else {
    if(vendor == NULL)
      printf("%-18s %-18s\n", ip_str, mac_str);
    else
      printf("%-18s %-18s(%s)\n", ip_str, mac_str, get_mac_vendor_str(file, mac_str));
  }

}

bool print_hosts(struct host_list* list, u_int32_t this_host) {
  int dbfd;
  char* file = NULL;
  struct stat st;

  if(list == NULL) {
    fprintf(stderr, "WARNING: No hosts found!\n");
    return true;
  }

  if((dbfd = open(MACDB_PATH1 MACDB_FILE, O_RDONLY)) == -1 && (dbfd = open(MACDB_PATH2 MACDB_FILE, O_RDONLY)) == -1) {
    fprintf(stderr, "WARNING: MAC vendors will not be shown\n%s: ",MACDB_FILE);
    perror("open");
  }
  else {
    if(fstat(dbfd, &st) != 0) {
      perror("stat");
      return false;
    }

    file = malloc(sizeof(char)* st.st_size);
    read(dbfd, file, st.st_size);
  }

  printf("\n%-18s %-18s\n", "IP Addess", "MAC Address");
  while(list->next != NULL) {
    print_host(file, list->ip_str, list->mac_str, get_mac_vendor_str(file, list->mac_str), list->ip, this_host);
    list = list->next;
  }
  if(list != NULL)
    print_host(file, list->ip_str, list->mac_str, get_mac_vendor_str(file, list->mac_str), list->ip, this_host);
  free(file);

  return true;
}