error.c

/**
 * error.c - Code and data for Error Handling
 *
 * Author: Thomas Cherryhomes <thom.cherryhomes@gmail.com>
 * Version: 1.0
 */

#include <string.h>
#include "error.h"
#include "log.h"
#include <syslog.h>

int error_code=0;
char error_message[2048];

void set_error(int _error_code, const char* _error_message)
{
  error_code=_error_code;
  strncpy(error_message,_error_message,sizeof(error_message));
}

void return_error(struct mg_connection* nc, struct http_message* hm)
{
  int http_result_code=500;
  char* path = NULL;
  char reply[1024];

  if (nc==NULL)
    {
      syslog(LOG_ALERT,"return_error(): mg_connection is NULL, so can't return error to client! error code %d, error message: %s",error_code, error_message);
      return;
    }

  if (hm==NULL)
    {
      syslog(LOG_ALERT,"return_error(): http_message was NULL, so can't form access log output. error code was %d, error message was: %s",error_code, error_message);
    }

  switch(error_code)
    {
    case ERROR_PATH_NOT_FOUND:
      http_result_code=404;
      break;
    case ERROR_NULL_VALUE:
    case ERROR_EMPTY_VALUE:
      http_result_code=400;
      break;
    default:
      http_result_code=500;
      break;
    }

  path=strndup(hm->uri.p,hm->uri.len);

  snprintf(reply,sizeof(reply),"{ \"result\": \"error\", \"error_code\":\"%d\", \"error_message\":\"%s\" }", error_code,error_message);
  mg_printf(nc,"HTTP/1.1 %d OK\r\nContent-Type: application/json\r\nContent-Length: %d\r\n\r\n%s",http_result_code,strlen(reply),reply);
  syslog(LOG_ALERT,"return_error(): error code %d, error message: %s",error_code,error_message);
  access_log(nc,hm,"GET",http_result_code,0);
  free(path);
}