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 __attribute__ ((visibility ("hidden")))
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 __attribute__ ((visibility ("hidden")))
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 __attribute__ ((visibility ("hidden")))
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);
}

/*
 * vim:sts=4:sw=4:tw=80
 */