source: lib/misc.c @ fd213fe

  /********************************************************************\
  * BitlBee -- An IRC to other IM-networks gateway                     *
  *                                                                    *
  * Copyright 2002-2012 Wilmer van der Gaast and others                *
  \********************************************************************/

/*
 * Various utility functions. Some are copied from Gaim to support the
 * IM-modules, most are from BitlBee.
 *
 * Copyright (C) 1998-1999, Mark Spencer <markster@marko.net>
 *                          (and possibly other members of the Gaim team)
 * Copyright 2002-2012 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 with
  the Debian GNU/Linux distribution in /usr/share/common-licenses/GPL;
  if not, write to the Free Software Foundation, Inc., 51 Franklin St.,
  Fifth Floor, Boston, MA  02110-1301  USA
*/

#define BITLBEE_CORE
#include "nogaim.h"
#include "base64.h"
#include "md5.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <glib.h>
#include <time.h>

#ifdef HAVE_RESOLV_A
#include <arpa/nameser.h>
#include <resolv.h>
#endif

#include "md5.h"
#include "ssl_client.h"

void strip_linefeed(gchar *text)
{
        int i, j;
        gchar *text2 = g_malloc(strlen(text) + 1);

        for (i = 0, j = 0; text[i]; i++)
                if (text[i] != '\r')
                        text2[j++] = text[i];
        text2[j] = '\0';

        strcpy(text, text2);
        g_free(text2);
}

time_t get_time(int year, int month, int day, int hour, int min, int sec)
{
        struct tm tm;

        memset(&tm, 0, sizeof(struct tm));
        tm.tm_year = year - 1900;
        tm.tm_mon = month - 1;
        tm.tm_mday = day;
        tm.tm_hour = hour;
        tm.tm_min = min;
        tm.tm_sec = sec >= 0 ? sec : time(NULL) % 60;
        
        return mktime(&tm);
}

time_t mktime_utc( struct tm *tp )
{
        struct tm utc;
        time_t res, tres;
        
        tp->tm_isdst = -1;
        res = mktime( tp );
        /* Problem is, mktime() just gave us the GMT timestamp for the
           given local time... While the given time WAS NOT local. So
           we should fix this now.
           
           Now I could choose between messing with environment variables
           (kludgy) or using timegm() (not portable)... Or doing the
           following, which I actually prefer...
           
           tzset() may also work but in other places I actually want to
           use local time.
           
           FFFFFFFFFFFFFFFFFFFFFUUUUUUUUUUUUUUUUUUUU!! */
        gmtime_r( &res, &utc );
        utc.tm_isdst = -1;
        if( utc.tm_hour == tp->tm_hour && utc.tm_min == tp->tm_min )
                /* Sweet! We're in UTC right now... */
                return res;
        
        tres = mktime( &utc );
        res += res - tres;
        
        /* Yes, this is a hack. And it will go wrong around DST changes.
           BUT this is more likely to be threadsafe than messing with
           environment variables, and possibly more portable... */
        
        return res;
}

typedef struct htmlentity
{
        char code[7];
        char is[3];
} htmlentity_t;

static const htmlentity_t ent[] =
{
        { "lt",     "<" },
        { "gt",     ">" },
        { "amp",    "&" },
        { "apos",   "'" },
        { "quot",   "\"" },
        { "aacute", "á" },
        { "eacute", "é" },
        { "iacute", "é" },
        { "oacute", "ó" },
        { "uacute", "ú" },
        { "agrave", "à" },
        { "egrave", "è" },
        { "igrave", "ì" },
        { "ograve", "ò" },
        { "ugrave", "ù" },
        { "acirc",  "â" },
        { "ecirc",  "ê" },
        { "icirc",  "î" },
        { "ocirc",  "ô" },
        { "ucirc",  "û" },
        { "auml",   "ä" },
        { "euml",   "ë" },
        { "iuml",   "ï" },
        { "ouml",   "ö" },
        { "uuml",   "ü" },
        { "nbsp",   " " },
        { "",        ""  }
};

void strip_html( char *in )
{
        char *start = in;
        char out[strlen(in)+1];
        char *s = out, *cs;
        int i, matched;
        int taglen;
        
        memset( out, 0, sizeof( out ) );
        
        while( *in )
        {
                if( *in == '<' && ( g_ascii_isalpha( *(in+1) ) || *(in+1) == '/' ) )
                {
                        /* If in points at a < and in+1 points at a letter or a slash, this is probably
                           a HTML-tag. Try to find a closing > and continue there. If the > can't be
                           found, assume that it wasn't a HTML-tag after all. */
                        
                        cs = in;
                        
                        while( *in && *in != '>' )
                                in ++;
                        
                        taglen = in - cs - 1;   /* not <0 because the above loop runs at least once */
                        if( *in )
                        {
                                if( g_strncasecmp( cs+1, "b", taglen) == 0 )
                                        *(s++) = '\x02';
                                else if( g_strncasecmp( cs+1, "/b", taglen) == 0 )
                                        *(s++) = '\x02';
                                else if( g_strncasecmp( cs+1, "i", taglen) == 0 )
                                        *(s++) = '\x1f';
                                else if( g_strncasecmp( cs+1, "/i", taglen) == 0 )
                                        *(s++) = '\x1f';
                                else if( g_strncasecmp( cs+1, "br", taglen) == 0 )
                                        *(s++) = '\n';
                                in ++;
                        }
                        else
                        {
                                in = cs;
                                *(s++) = *(in++);
                        }
                }
                else if( *in == '&' )
                {
                        cs = ++in;
                        while( *in && g_ascii_isalpha( *in ) )
                                in ++;
                        
                        if( *in == ';' ) in ++;
                        matched = 0;
                        
                        for( i = 0; *ent[i].code; i ++ )
                                if( g_strncasecmp( ent[i].code, cs, strlen( ent[i].code ) ) == 0 )
                                {
                                        int j;
                                        
                                        for( j = 0; ent[i].is[j]; j ++ )
                                                *(s++) = ent[i].is[j];
                                        
                                        matched = 1;
                                        break;
                                }

                        /* None of the entities were matched, so return the string */
                        if( !matched )
                        {
                                in = cs - 1;
                                *(s++) = *(in++);
                        }
                }
                else
                {
                        *(s++) = *(in++);
                }
        }
        
        strcpy( start, out );
}

char *escape_html( const char *html )
{
        const char *c = html;
        GString *ret;
        char *str;
        
        if( html == NULL )
                return( NULL );
        
        ret = g_string_new( "" );
        
        while( *c )
        {
                switch( *c )
                {
                        case '&':
                                ret = g_string_append( ret, "&amp;" );
                                break;
                        case '<':
                                ret = g_string_append( ret, "&lt;" );
                                break;
                        case '>':
                                ret = g_string_append( ret, "&gt;" );
                                break;
                        case '"':
                                ret = g_string_append( ret, "&quot;" );
                                break;
                        default:
                                ret = g_string_append_c( ret, *c );
                }
                c ++;
        }
        
        str = ret->str;
        g_string_free( ret, FALSE );
        return( str );
}

/* Decode%20a%20file%20name                                             */
void http_decode( char *s )
{
        char *t;
        int i, j, k;
        
        t = g_new( char, strlen( s ) + 1 );
        
        for( i = j = 0; s[i]; i ++, j ++ )
        {
                if( s[i] == '%' )
                {
                        if( sscanf( s + i + 1, "%2x", &k ) )
                        {
                                t[j] = k;
                                i += 2;
                        }
                        else
                        {
                                *t = 0;
                                break;
                        }
                }
                else
                {
                        t[j] = s[i];
                }
        }
        t[j] = 0;
        
        strcpy( s, t );
        g_free( t );
}

/* Warning: This one explodes the string. Worst-cases can make the string 3x its original size! */
/* This fuction is safe, but make sure you call it safely as well! */
void http_encode( char *s )
{
        char t[strlen(s)+1];
        int i, j;
        
        strcpy( t, s );
        for( i = j = 0; t[i]; i ++, j ++ )
        {
                /* Warning: g_ascii_isalnum() is locale-aware, so don't use it here! */
                if( ( t[i] >= 'A' && t[i] <= 'Z' ) ||
                    ( t[i] >= 'a' && t[i] <= 'z' ) ||
                    ( t[i] >= '0' && t[i] <= '9' ) ||
                    strchr( "._-~", t[i] ) )
                {
                        s[j] = t[i];
                }
                else
                {
                        sprintf( s + j, "%%%02X", ((unsigned char*)t)[i] );
                        j += 2;
                }
        }
        s[j] = 0;
}

/* Strip newlines from a string. Modifies the string passed to it. */ 
char *strip_newlines( char *source )
{
        int i;  

        for( i = 0; source[i] != '\0'; i ++ )
                if( source[i] == '\n' || source[i] == '\r' )
                        source[i] = ' ';
        
        return source;
}

/* Wrap an IPv4 address into IPv6 space. Not thread-safe... */
char *ipv6_wrap( char *src )
{
        static char dst[64];
        int i;
        
        for( i = 0; src[i]; i ++ )
                if( ( src[i] < '0' || src[i] > '9' ) && src[i] != '.' )
                        break;
        
        /* Hmm, it's not even an IP... */
        if( src[i] )
                return src;
        
        g_snprintf( dst, sizeof( dst ), "::ffff:%s", src );
        
        return dst;
}

/* Unwrap an IPv4 address into IPv6 space. Thread-safe, because it's very simple. :-) */
char *ipv6_unwrap( char *src )
{
        int i;
        
        if( g_strncasecmp( src, "::ffff:", 7 ) != 0 )
                return src;
        
        for( i = 7; src[i]; i ++ )
                if( ( src[i] < '0' || src[i] > '9' ) && src[i] != '.' )
                        break;
        
        /* Hmm, it's not even an IP... */
        if( src[i] )
                return src;
        
        return ( src + 7 );
}

/* Convert from one charset to another.
   
   from_cs, to_cs: Source and destination charsets
   src, dst: Source and destination strings
   size: Size if src. 0 == use strlen(). strlen() is not reliable for UNICODE/UTF16 strings though.
   maxbuf: Maximum number of bytes to write to dst
   
   Returns the number of bytes written to maxbuf or -1 on an error.
*/
signed int do_iconv( char *from_cs, char *to_cs, char *src, char *dst, size_t size, size_t maxbuf )
{
        GIConv cd;
        size_t res;
        size_t inbytesleft, outbytesleft;
        char *inbuf = src;
        char *outbuf = dst;
        
        cd = g_iconv_open( to_cs, from_cs );
        if( cd == (GIConv) -1 )
                return -1;
        
        inbytesleft = size ? size : strlen( src );
        outbytesleft = maxbuf - 1;
        res = g_iconv( cd, &inbuf, &inbytesleft, &outbuf, &outbytesleft );
        *outbuf = '\0';
        g_iconv_close( cd );
        
        if( res != 0 )
                return -1;
        else
                return outbuf - dst;
}

/* A pretty reliable random number generator. Tries to use the /dev/random
   devices first, and falls back to the random number generator from libc
   when it fails. Opens randomizer devices with O_NONBLOCK to make sure a
   lack of entropy won't halt BitlBee. */
void random_bytes( unsigned char *buf, int count )
{
        static int use_dev = -1;
        
        /* Actually this probing code isn't really necessary, is it? */
        if( use_dev == -1 )
        {
                if( access( "/dev/random", R_OK ) == 0 || access( "/dev/urandom", R_OK ) == 0 )
                        use_dev = 1;
                else
                {
                        use_dev = 0;
                        srand( ( getpid() << 16 ) ^ time( NULL ) );
                }
        }
        
        if( use_dev )
        {
                int fd;
                
                /* At least on Linux, /dev/random can block if there's not
                   enough entropy. We really don't want that, so if it can't
                   give anything, use /dev/urandom instead. */
                if( ( fd = open( "/dev/random", O_RDONLY | O_NONBLOCK ) ) >= 0 )
                        if( read( fd, buf, count ) == count )
                        {
                                close( fd );
                                return;
                        }
                close( fd );
                
                /* urandom isn't supposed to block at all, but just to be
                   sure. If it blocks, we'll disable use_dev and use the libc
                   randomizer instead. */
                if( ( fd = open( "/dev/urandom", O_RDONLY | O_NONBLOCK ) ) >= 0 )
                        if( read( fd, buf, count ) == count )
                        {
                                close( fd );
                                return;
                        }
                close( fd );
                
                /* If /dev/random blocks once, we'll still try to use it
                   again next time. If /dev/urandom also fails for some
                   reason, stick with libc during this session. */
                
                use_dev = 0;
                srand( ( getpid() << 16 ) ^ time( NULL ) );
        }
        
        if( !use_dev )
        {
                int i;
                
                /* Possibly the LSB of rand() isn't very random on some
                   platforms. Seems okay on at least Linux and OSX though. */
                for( i = 0; i < count; i ++ )
                        buf[i] = rand() & 0xff;
        }
}

int is_bool( char *value )
{
        if( *value == 0 )
                return 0;
        
        if( ( g_strcasecmp( value, "true" ) == 0 ) || ( g_strcasecmp( value, "yes" ) == 0 ) || ( g_strcasecmp( value, "on" ) == 0 ) )
                return 1;
        if( ( g_strcasecmp( value, "false" ) == 0 ) || ( g_strcasecmp( value, "no" ) == 0 ) || ( g_strcasecmp( value, "off" ) == 0 ) )
                return 1;
        
        while( *value )
                if( !g_ascii_isdigit( *value ) )
                        return 0;
                else
                        value ++;
        
        return 1;
}

int bool2int( char *value )
{
        int i;
        
        if( ( g_strcasecmp( value, "true" ) == 0 ) || ( g_strcasecmp( value, "yes" ) == 0 ) || ( g_strcasecmp( value, "on" ) == 0 ) )
                return 1;
        if( ( g_strcasecmp( value, "false" ) == 0 ) || ( g_strcasecmp( value, "no" ) == 0 ) || ( g_strcasecmp( value, "off" ) == 0 ) )
                return 0;
        
        if( sscanf( value, "%d", &i ) == 1 )
                return i;
        
        return 0;
}

struct ns_srv_reply **srv_lookup( char *service, char *protocol, char *domain )
{       
        struct ns_srv_reply **replies = NULL;
#ifdef HAVE_RESOLV_A
        struct ns_srv_reply *reply = NULL;
        char name[1024];
        unsigned char querybuf[1024];
        const unsigned char *buf;
        ns_msg nsh;
        ns_rr rr;
        int n, len, size;
        
        g_snprintf( name, sizeof( name ), "_%s._%s.%s", service, protocol, domain );
        
        if( ( size = res_query( name, ns_c_in, ns_t_srv, querybuf, sizeof( querybuf ) ) ) <= 0 )
                return NULL;
        
        if( ns_initparse( querybuf, size, &nsh ) != 0 )
                return NULL;
        
        n = 0;
        while( ns_parserr( &nsh, ns_s_an, n, &rr ) == 0 )
        {
                char name[NS_MAXDNAME];

                if( ns_rr_rdlen( rr ) < 7)
                    break;

                buf = ns_rr_rdata( rr );
                
                if( dn_expand(querybuf, querybuf + size, &buf[6], name, NS_MAXDNAME) == -1 )
                        break;

                len = strlen(name) + 1;
                
                reply = g_malloc( sizeof( struct ns_srv_reply ) + len );
                memcpy( reply->name, name, len );
                
                reply->prio = ( buf[0] << 8 ) | buf[1];
                reply->weight = ( buf[2] << 8 ) | buf[3];
                reply->port = ( buf[4] << 8 ) | buf[5];
                
                n ++;
                replies = g_renew( struct ns_srv_reply *, replies, n + 1 );
                replies[n-1] = reply;
        }
        if( replies )
                replies[n] = NULL;
#endif
        
        return replies;
}

void srv_free( struct ns_srv_reply **srv )
{
        int i;
        
        if( srv == NULL )
                return;
        
        for( i = 0; srv[i]; i ++ )
                g_free( srv[i] );
        g_free( srv );
}

/* Word wrapping. Yes, I know this isn't UTF-8 clean. I'm willing to take the risk. */
char *word_wrap( const char *msg, int line_len )
{
        GString *ret = g_string_sized_new( strlen( msg ) + 16 );
        
        while( strlen( msg ) > line_len )
        {
                int i;
                
                /* First try to find out if there's a newline already. Don't
                   want to add more splits than necessary. */
                for( i = line_len; i > 0 && msg[i] != '\n'; i -- );
                if( msg[i] == '\n' )
                {
                        g_string_append_len( ret, msg, i + 1 );
                        msg += i + 1;
                        continue;
                }
                
                for( i = line_len; i > 0; i -- )
                {
                        if( msg[i] == '-' )
                        {
                                g_string_append_len( ret, msg, i + 1 );
                                g_string_append_c( ret, '\n' );
                                msg += i + 1;
                                break;
                        }
                        else if( msg[i] == ' ' )
                        {
                                g_string_append_len( ret, msg, i );
                                g_string_append_c( ret, '\n' );
                                msg += i + 1;
                                break;
                        }
                }
                if( i == 0 )
                {
                        g_string_append_len( ret, msg, line_len );
                        g_string_append_c( ret, '\n' );
                        msg += line_len;
                }
        }
        g_string_append( ret, msg );
        
        return g_string_free( ret, FALSE );
}

gboolean ssl_sockerr_again( void *ssl )
{
        if( ssl )
                return ssl_errno == SSL_AGAIN;
        else
                return sockerr_again();
}

/* Returns values: -1 == Failure (base64-decoded to something unexpected)
                    0 == Okay
                    1 == Password doesn't match the hash. */
int md5_verify_password( char *password, char *hash )
{
        md5_byte_t *pass_dec = NULL;
        md5_byte_t pass_md5[16];
        md5_state_t md5_state;
        int ret = -1, i;
        
        if( base64_decode( hash, &pass_dec ) == 21 )
        {
                md5_init( &md5_state );
                md5_append( &md5_state, (md5_byte_t*) password, strlen( password ) );
                md5_append( &md5_state, (md5_byte_t*) pass_dec + 16, 5 ); /* Hmmm, salt! */
                md5_finish( &md5_state, pass_md5 );
                
                for( i = 0; i < 16; i ++ )
                {
                        if( pass_dec[i] != pass_md5[i] )
                        {
                                ret = 1;
                                break;
                        }
                }
                
                /* If we reached the end of the loop, it was a match! */
                if( i == 16 )
                        ret = 0;
        }
        
        g_free( pass_dec );

        return ret;
}

/* Split commands (root-style, *not* IRC-style). Handles "quoting of"
   white\ space in 'various ways'. Returns a NULL-terminated static
   char** so watch out with nested use! Definitely not thread-safe. */
char **split_command_parts( char *command, int limit )
{
        static char *cmd[IRC_MAX_ARGS+1];
        char *s, q = 0;
        int k;
        
        memset( cmd, 0, sizeof( cmd ) );
        cmd[0] = command;
        k = 1;
        for( s = command; *s && k < IRC_MAX_ARGS; s ++ )
        {
                if( *s == ' ' && !q )
                {
                        *s = 0;
                        while( *++s == ' ' );
                        if( k != limit && (*s == '"' || *s == '\'') )
                        {
                                q = *s;
                                s ++;
                        }
                        if( *s )
                        {
                                cmd[k++] = s;
                                if (limit && k > limit) {
                                        break;
                                }
                                s --;
                        }
                        else
                        {
                                break;
                        }
                }
                else if( *s == '\\' && ( ( !q && s[1] ) || ( q && q == s[1] ) ) )
                {
                        char *cpy;
                        
                        for( cpy = s; *cpy; cpy ++ )
                                cpy[0] = cpy[1];
                }
                else if( *s == q )
                {
                        q = *s = 0;
                }
        }
        
        /* Full zero-padding for easier argc checking. */
        while( k <= IRC_MAX_ARGS )
                cmd[k++] = NULL;
        
        return cmd;
}

char *get_rfc822_header( const char *text, const char *header, int len )
{
        int hlen = strlen( header ), i;
        const char *ret;
        
        if( text == NULL )
                return NULL;
        
        if( len == 0 )
                len = strlen( text );
        
        i = 0;
        while( ( i + hlen ) < len )
        {
                /* Maybe this is a bit over-commented, but I just hate this part... */
                if( g_strncasecmp( text + i, header, hlen ) == 0 )
                {
                        /* Skip to the (probable) end of the header */
                        i += hlen;
                        
                        /* Find the first non-[: \t] character */
                        while( i < len && ( text[i] == ':' || text[i] == ' ' || text[i] == '\t' ) ) i ++;
                        
                        /* Make sure we're still inside the string */
                        if( i >= len ) return( NULL );
                        
                        /* Save the position */
                        ret = text + i;
                        
                        /* Search for the end of this line */
                        while( i < len && text[i] != '\r' && text[i] != '\n' ) i ++;
                        
                        /* Make sure we're still inside the string */
                        if( i >= len ) return( NULL );
                        
                        /* Copy the found data */
                        return( g_strndup( ret, text + i - ret ) );
                }
                
                /* This wasn't the header we were looking for, skip to the next line. */
                while( i < len && ( text[i] != '\r' && text[i] != '\n' ) ) i ++;
                while( i < len && ( text[i] == '\r' || text[i] == '\n' ) ) i ++;
                
                /* End of headers? */
                if( ( i >= 4 && strncmp( text + i - 4, "\r\n\r\n", 4 ) == 0 ) ||
                    ( i >= 2 && ( strncmp( text + i - 2, "\n\n", 2 ) == 0 ||   
                                  strncmp( text + i - 2, "\r\r", 2 ) == 0 ) ) )
                {
                        break;
                }
        }
        
        return NULL;
}

/* Takes a string, truncates it where it's safe, returns the new length */
int truncate_utf8( char *string, int maxlen )
{
        char *end;
        g_utf8_validate( (const gchar *) string, maxlen, (const gchar **) &end );
        *end = '\0';
        return end - string;
}