common.c

/*

    commmon.c    - Common routines for the tsocks package 

*/

#include <config.h>
#include <stdio.h>
#include <netdb.h>
#include <common.h>
#include <stdarg.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <netinet/in.h>

/* Globals */
int loglevel = MSGERR;    /* The default logging level is to only log
                             error messages */
char logfilename[256];    /* Name of file to which log messages should
                             be redirected */
FILE *logfile = NULL;     /* File to which messages should be logged */
int logstamp = 0;         /* Timestamp (and pid stamp) messages */

unsigned int resolve_ip(char *host, int showmsg, int allownames) {
	struct hostent *new;
	unsigned int	hostaddr;
	struct in_addr *ip;

	if ((hostaddr = inet_addr(host)) == (unsigned int) -1) {
		/* We couldn't convert it as a numerical ip so */
		/* try it as a dns name                        */
		if (allownames) {
			#ifdef HAVE_GETHOSTBYNAME
			if ((new = gethostbyname(host)) == (struct hostent *) 0) {
			#endif
				return(-1);
			#ifdef HAVE_GETHOSTBYNAME
			} else {
				ip = ((struct in_addr *) * new->h_addr_list);
				hostaddr = ip -> s_addr;
				if (showmsg) 
					printf("Connecting to %s...\n", inet_ntoa(*ip));
			}
			#endif
		} else
			return(-1);
	}

	return (hostaddr);
}

/* Set logging options, the options are as follows:             */
/*  level - This sets the logging threshold, messages with      */
/*          a higher level (i.e lower importance) will not be   */
/*          output. For example, if the threshold is set to     */
/*          MSGWARN a call to log a message of level MSGDEBUG   */
/*          would be ignored. This can be set to -1 to disable  */
/*          messages entirely                                   */
/*  filename - This is a filename to which the messages should  */
/*             be logged instead of to standard error           */
/*  timestamp - This indicates that messages should be prefixed */
/*              with timestamps (and the process id)            */
void set_log_options(int level, char *filename, int timestamp) {

   loglevel = level;
   if (loglevel < MSGERR)
      loglevel = MSGNONE;

   if (filename) {
      strncpy(logfilename, filename, sizeof(logfilename));
      logfilename[sizeof(logfilename) - 1] = '\0';
   }

   logstamp = timestamp;
}

void show_msg(int level, char *fmt, ...) {
	va_list ap;
	int saveerr;
	extern char *progname;
   char timestring[20];
   time_t timestamp;

   if ((loglevel == MSGNONE) || (level > loglevel))
      return;

   if (!logfile) {
      if (logfilename[0]) {
         logfile = fopen(logfilename, "a");
         if (logfile == NULL) {
            logfile = stderr;
            show_msg(MSGERR, "Could not open log file, %s, %s\n", 
                     logfilename, strerror(errno));
         }
      } else
         logfile = stderr;
   }

   if (logstamp) {
      timestamp = time(NULL);
      strftime(timestring, sizeof(timestring),  "%H:%M:%S", 
               localtime(&timestamp));
      fprintf(logfile, "%s ", timestring);
   }

   fputs(progname, logfile);

   if (logstamp) {
      fprintf(logfile, "(%d)", getpid());
   }
   
   fputs(": ", logfile);
	
	va_start(ap, fmt);

	/* Save errno */
	saveerr = errno;

	vfprintf(logfile, fmt, ap);
	
   fflush(logfile);

	errno = saveerr;

	va_end(ap);
}