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/***************************************************************************\
*                                                                           *
*  BitlBee - An IRC to IM gateway                                           *
*  Base64 handling functions. encode_real() is mostly based on the y64 en-  *
*  coder from libyahoo2. Moving it to a new file because it's getting big.  *
*                                                                           *
*  Copyright 2006 Wilmer van der Gaast <wilmer@gaast.net>                   *
*                                                                           *
*  This program is free software; you can redistribute it and/or modify     *
*  it under the terms of the GNU General Public License as published by     *
*  the Free Software Foundation; either version 2 of the License, or        *
*  (at your option) any later version.                                      *
*                                                                           *
*  This program is distributed in the hope that it will be useful,          *
*  but WITHOUT ANY WARRANTY; without even the implied warranty of           *
*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            *
*  GNU General Public License for more details.                             *
*                                                                           *
*  You should have received a copy of the GNU General Public License along  *
*  with this program; if not, write to the Free Software Foundation, Inc.,  *
*  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.              *
*                                                                           *
\***************************************************************************/

#include <glib.h>
#include <string.h>
#include "base64.h"

static const char real_b64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";

char *tobase64(const char *text)
{
	return base64_encode((const unsigned char *)text, strlen(text));
}

char *base64_encode(const unsigned char *in, int len)
{
	char *out;
	
	out = g_malloc((len + 2)    /* the == padding */
	                    / 3     /* every 3-byte block */
	                    * 4     /* becomes a 4-byte one */
	                    + 1);   /* and of course, ASCIIZ! */
	
	base64_encode_real((unsigned char*) in, len, (unsigned char*) out, real_b64);
	
	return out;
}

int base64_encode_real(const unsigned char *in, int inlen, unsigned char *out, const char *b64digits)
{
	int outlen = 0;
	
	for (; inlen >= 3; inlen -= 3)
	{
		out[outlen++] = b64digits[in[0] >> 2];
		out[outlen++] = b64digits[((in[0]<<4) & 0x30) | (in[1]>>4)];
		out[outlen++] = b64digits[((in[1]<<2) & 0x3c) | (in[2]>>6)];
		out[outlen++] = b64digits[in[2] & 0x3f];
		in += 3;
	}
	if (inlen > 0)
	{
		out[outlen++] = b64digits[in[0] >> 2];
		if (inlen > 1)
		{
			out[outlen++] = b64digits[((in[0]<<4) & 0x30) | (in[1]>>4)];
			out[outlen++] = b64digits[((in[1]<<2) & 0x3c)];
		}
		else
		{
			out[outlen++] = b64digits[((in[0]<<4) & 0x30)];
			out[outlen++] = b64digits[64];
		}
		out[outlen++] = b64digits[64];
	}
	out[outlen] = 0;
	
	return outlen;
}

/* Just a simple wrapper, but usually not very convenient because of zero
   termination. */
char *frombase64(const char *in)
{
	unsigned char *out;
	
	base64_decode(in, &out);
	
	return (char*) out;
}

/* FIXME: Lookup table stuff is not threadsafe! (But for now BitlBee is not threaded.) */
int base64_decode(const char *in, unsigned char **out)
{
	static char b64rev[256] = { 0 };
	int len, i;
	
	/* Create a reverse-lookup for the Base64 sequence. */
	if( b64rev[0] == 0 )
	{
		memset( b64rev, 0xff, 256 );
		for( i = 0; i <= 64; i ++ )
			b64rev[(int)real_b64[i]] = i;
	}
	
	len = strlen( in );
	*out = g_malloc( ( len + 6 ) / 4 * 3 );
	len = base64_decode_real( (unsigned char*) in, *out, b64rev );
	*out = g_realloc( *out, len + 1 );
	out[0][len] = 0;	/* Zero termination can't hurt. */
	
	return len;
}

int base64_decode_real(const unsigned char *in, unsigned char *out, char *b64rev)
{
	int i, outlen = 0;
	
	for( i = 0; in[i] && in[i+1] && in[i+2] && in[i+3]; i += 4 )
	{
		int sx;
		
		sx = b64rev[(int)in[i+0]];
		if( sx >= 64 )
			break;
		out[outlen] = ( sx << 2 ) & 0xfc;
		
		sx = b64rev[(int)in[i+1]];
		if( sx >= 64 )
			break;
		out[outlen] |= ( sx >> 4 ) & 0x03;
		outlen ++;
		out[outlen] = ( sx << 4 ) & 0xf0;
		
		sx = b64rev[(int)in[i+2]];
		if( sx >= 64 )
			break;
		out[outlen] |= ( sx >> 2 ) & 0x0f;
		outlen ++;
		out[outlen] = ( sx << 6 ) & 0xc0;
		
		sx = b64rev[(int)in[i+3]];
		if( sx >= 64 )
			break;
		out[outlen] |= sx;
		outlen ++;
	}
	
	/* If sx > 64 the base64 string was damaged. Should we ignore this? */
	
	return outlen;
}
ass="p">( "bind" ); return( 1 ); } } if( listen( serv_fd, set->max_conn ) != 0 ) { perror( "listen" ); return( 1 ); } if ( ! set->debug ) { st = fork(); if( st < 0 ) { perror( "fork" ); return( 1 ); } else if( st > 0 ) { return( 0 ); } setsid(); close( 0 ); close( 1 ); close( 2 ); } do_log( "bitlbeed running" ); /* The Daemon */ while( 1 ) { int cli_fd, cli_len, i, st; struct sockaddr_in cli_addr; struct sockaddr_un cli_local; ipstats_t *ip; char *cli_txt; pid_t child; static int running = 0; fd_set rd; struct timeval tm; /* accept() only returns after someone connects. To clean up old processes (by running waitpid()) it's better to use select() with a timeout. */ FD_ZERO( &rd ); FD_SET( serv_fd, &rd ); tm.tv_sec = SELECT_TIMEOUT; tm.tv_usec = 0; if( select( serv_fd + 1, &rd, NULL, NULL, &tm ) > 0 ) { if (set->local) { cli_len = SUN_LEN( &cli_local ); cli_fd = accept( serv_fd, (struct sockaddr *) &cli_local, &cli_len ); cli_txt = "127.0.0.1"; } else { cli_len = sizeof( cli_addr ); cli_fd = accept( serv_fd, (struct sockaddr *) &cli_addr, &cli_len ); cli_txt = inet_ntoa( cli_addr.sin_addr ); } ip = ip_get( cli_txt ); if( set->rate_times == 0 || time( NULL ) > ip->rate_ignore ) { /* We want this socket on stdout and stderr too! */ dup( cli_fd ); dup( cli_fd ); if( ( child = fork() ) == 0 ) { if( set->seconds ) { struct rlimit li; li.rlim_cur = (rlim_t) set->seconds; li.rlim_max = (rlim_t) set->seconds + 1; setrlimit( RLIMIT_CPU, &li ); } execv( set->call[0], set->call ); do_log( "Error while executing %s!", set->call[0] ); return( 1 ); } running ++; close( 0 ); close( 1 ); close( 2 ); do_log( "Started child process for client %s (PID=%d), got %d clients now", cli_txt, child, running ); if( time( NULL ) < ( ip->rate_start + set->rate_seconds ) ) { ip->rate_times ++; if( ip->rate_times >= set->rate_times ) { do_log( "Client %s crossed the limit; ignoring for the next %d seconds", cli_txt, set->rate_ignore ); ip->rate_ignore = time( NULL ) + set->rate_ignore; ip->rate_start = 0; } } else { ip->rate_start = time( NULL ); ip->rate_times = 1; } } else { do_log( "Ignoring connection from %s", cli_txt ); close( cli_fd ); } } /* If the max. number of connection is reached, don't accept new connections until one expires -> Not always WNOHANG Cleaning up child processes is a good idea anyway... :-) */ while( ( i = waitpid( 0, &st, ( ( running < set->max_conn ) || ( set->max_conn == 0 ) ) ? WNOHANG : 0 ) ) > 0 ) { running --; if( WIFEXITED( st ) ) { do_log( "Child process (PID=%d) exited normally with status %d. %d Clients left now", i, WEXITSTATUS( st ), running ); } else if( WIFSIGNALED( st ) ) { do_log( "Child process (PID=%d) killed by signal %d. %d Clients left now", i, WTERMSIG( st ), running ); } else { /* Should not happen AFAIK... */ do_log( "Child process (PID=%d) stopped for unknown reason, %d clients left now", i, running ); } } } return( 0 ); } settings_t *set_load( int argc, char *argv[] ) { settings_t *set; int opt, i; set = malloc( sizeof( settings_t ) ); memset( set, 0, sizeof( settings_t ) ); set->interface = NULL; /* will be filled in later */ set->port = 6667; set->local = 0; set->debug = 0; set->rate_seconds = 600; set->rate_times = 5; set->rate_ignore = 900; while( ( opt = getopt( argc, argv, "i:p:n:t:l:r:hud" ) ) >= 0 ) { if( opt == 'i' ) { set->interface = strdup( optarg ); } else if( opt == 'p' ) { if( ( sscanf( optarg, "%d", &i ) != 1 ) || ( i <= 0 ) || ( i > 65535 ) ) { fprintf( stderr, "Invalid port number: %s\n", optarg ); return( NULL ); } set->port = i; } else if( opt == 'n' ) { if( ( sscanf( optarg, "%d", &i ) != 1 ) || ( i < 0 ) ) { fprintf( stderr, "Invalid number of connections: %s\n", optarg ); return( NULL ); } set->max_conn = i; } else if( opt == 't' ) { if( ( sscanf( optarg, "%d", &i ) != 1 ) || ( i < 0 ) || ( i > 600 ) ) { fprintf( stderr, "Invalid number of seconds: %s\n", optarg ); return( NULL ); } set->seconds = i; } else if( opt == 'l' ) { if( !( logfile = fopen( optarg, "a" ) ) ) { perror( "fopen" ); fprintf( stderr, "Error opening logfile, giving up.\n" ); return( NULL ); } setbuf( logfile, NULL ); } else if( opt == 'r' ) { if( sscanf( optarg, "%d,%d,%d", &set->rate_seconds, &set->rate_times, &set->rate_ignore ) != 3 ) { fprintf( stderr, "Invalid argument to -r.\n" ); return( NULL ); } } else if( opt == 'u' ) set->local = 1; else if( opt == 'd' ) set->debug = 1; else if( opt == 'h' ) { printf( "Usage: %s [-i <interface>] [-p <port>] [-n <num>] [-r x,y,z] ...\n" " ... <command> <args...>\n" "A simple inetd-like daemon to have a program listening on a TCP socket without\n" "needing root access to the machine\n" "\n" " -i Specify the interface (by IP address) to listen on.\n" " (Default: 0.0.0.0 (any interface))\n" " -p Port number to listen on. (Default: 6667)\n" " -n Maximum number of connections. (Default: 0 (unlimited))\n" " -t Specify the maximum number of CPU seconds per process.\n" " (Default: 0 (unlimited))\n" " -l Specify a logfile. (Default: none)\n" " -r Rate limiting: Ignore a host for z seconds when it connects for more\n" " than y times in x seconds. (Default: 600,5,900. Disable: 0,0,0)\n" " -u Use a local socket, by default /tmp/bitlbee (override with -i <filename>)\n" " -d Don't fork for listening (for debugging purposes)\n" " -h This information\n", argv[0] ); return( NULL ); } } if( set->interface == NULL ) set->interface = (set->local) ? "/tmp/bitlbee" : "0.0.0.0"; if( optind == argc ) { fprintf( stderr, "Missing program parameter!\n" ); return( NULL ); } /* The remaining arguments are the executable and its arguments */ set->call = malloc( ( argc - optind + 1 ) * sizeof( char* ) ); memcpy( set->call, argv + optind, sizeof( char* ) * ( argc - optind ) ); set->call[argc-optind] = NULL; return( set ); } void do_log( char *fmt, ... ) { va_list params; char line[MAX_LOG_LEN]; time_t tm; int l; memset( line, 0, MAX_LOG_LEN ); tm = time( NULL ); strcpy( line, ctime( &tm ) ); l = strlen( line ); line[l-1] = ' '; va_start( params, fmt ); vsnprintf( line + l, MAX_LOG_LEN - l - 2, fmt, params ); va_end( params ); strcat( line, "\n" ); fprintf( logfile, "%s", line ); } ipstats_t *ip_get( char *ip_txt ) { unsigned int ip; ipstats_t *l; int p[4]; sscanf( ip_txt, "%d.%d.%d.%d", p + 0, p + 1, p + 2, p + 3 ); ip = ( p[0] << 24 ) | ( p[1] << 16 ) | ( p[2] << 8 ) | ( p[3] ); for( l = ipstats; l; l = l->next ) { if( l->ip == ip ) return( l ); } if( ipstats ) { for( l = ipstats; l->next; l = l->next ); l->next = malloc( sizeof( ipstats_t ) ); l = l->next; } else { l = malloc( sizeof( ipstats_t ) ); ipstats = l; } memset( l, 0, sizeof( ipstats_t ) ); l->ip = ip; return( l ); }