advanced features */ $bpfbufsize = $config['installedpackages']['snortadvanced']['config'][0]['bpfbufsize']; $bpfmaxbufsize = $config['installedpackages']['snortadvanced']['config'][0]['bpfmaxbufsize']; $bpfmaxinsns = $config['installedpackages']['snortadvanced']['config'][0]['bpfmaxinsns']; /* set the snort performance model */ if($config['installedpackages']['snort']['config'][0]['performance']) $snort_performance = $config['installedpackages']['snort']['config'][0]['performance']; else $snort_performance = "ac-bnfa"; conf_mount_rw(); /* create a few directories and ensure the sample files are in place */ exec("/bin/mkdir -p /usr/local/etc/snort"); exec("/bin/mkdir -p /var/log/snort"); exec("/bin/cp /usr/local/etc/snort/unicode.map-sample /usr/local/etc/snort/unicode.map"); exec("/bin/cp /usr/local/etc/snort/classification.config-sample /usr/local/etc/snort/classification.config"); exec("/bin/cp /usr/local/etc/snort/gen-msg.map-sample /usr/local/etc/snort/gen-msg.map"); exec("/bin/cp /usr/local/etc/snort/generators-sample /usr/local/etc/snort/generators"); exec("/bin/cp /usr/local/etc/snort/reference.config-sample /usr/local/etc/snort/reference.config"); exec("/bin/cp /usr/local/etc/snort/sid-msg.map-sample /usr/local/etc/snort/sid-msg.map"); exec("/bin/cp /usr/local/etc/snort/sid-sample /usr/local/etc/snort/sid"); exec("/bin/cp /usr/local/etc/snort/threshold.conf-sample /usr/local/etc/snort/threshold.conf"); exec("/bin/cp /usr/local/etc/snort/unicode.map-sample /usr/local/etc/snort/unicode.map"); exec("/bin/rm -f /usr/local/etc/rc.d/snort"); $first = 0; $snortInterfaces = array(); /* -gtm */ $if_list = $config['installedpackages']['snort']['config'][0]['iface_array']; $if_array = split(',', $if_list); //print_r($if_array); if($if_array) { foreach($if_array as $iface) { $if = convert_friendly_interface_to_real_interface_name($iface); if($config['interfaces'][$iface]['ipaddr'] == "pppoe") { $if = "ng0"; } /* build a list of user specified interfaces -gtm */ if($if){ array_push($snortInterfaces, $if); $first = 1; } } if (count($snortInterfaces) < 1) { //log_error("Snort will not start. You must select an interface for it to listen on."); echo "Snort will not start. You must select an interface for it to listen on."; return; } } //print_r($snortInterfaces); /* create log directory */ $start = "/bin/mkdir -p /var/log/snort"; /* snort advanced features - bpf tuning */ if($bpfbufsize) $start .= ";sysctl net.bpf.bufsize={$bpfbufsize}"; if($bpfmaxbufsize) $start .= ";sysctl net.bpf.maxbufsize={$bpfmaxbufsize}"; if($bpfmaxinsns) $start .= ";sysctl net.bpf.maxinsns={$bpfmaxinsns}"; /* go ahead and issue bpf changes */ if($bpfbufsize) mwexec_bg("sysctl net.bpf.bufsize={$bpfbufsize}"); if($bpfmaxbufsize) mwexec_bg("sysctl net.bpf.maxbufsize={$bpfmaxbufsize}"); if($bpfmaxinsns) mwexec_bg("sysctl net.bpf.maxinsns={$bpfmaxinsns}"); /* always stop snort2c before starting snort -gtm */ $start .= ";/usr/bin/killall snort2c"; /* start a snort process for each interface -gtm */ /* Note the sleep delay. Seems to help getting mult interfaces to start -gtm */ foreach($snortInterfaces as $snortIf) { $start .= ";sleep 8;snort -c /usr/local/etc/snort/snort.conf -l /var/log/snort -D -i {$snortIf} -A fast &"; } /* if block offenders is checked, start snort2c */ if($_POST['blockoffenders']) $start .= ";sleep 8;snort2c -w /var/db/whitelist -a /var/log/snort/alert"; $sample_before = "\nBEFORE_MEM=`top | grep Free | grep Wired | awk '{print \$10}'`\n"; $sample_after = "\nAFTER_MEM=`top | grep Free | grep Wired | awk '{print \$10}'`\n"; $sleep_before_final = "\necho \"Sleeping before final memory sampling...\"\nsleep 17"; $total_free_after = "\nTOTAL_USAGE=`top | grep snort | grep -v grep | awk '{ print \$6 }'`\n"; $echo_usage = "\necho \"Ram free BEFORE starting Snort: \${BEFORE_MEM} -- Ram free AFTER starting Snort: \${AFTER_MEM}\" -- Mode {$snort_performance} -- Snort memory usage: \$TOTAL_USAGE | logger -p daemon.info -i -t SnortStartup\n"; /* write out rc.d start/stop file */ write_rcfile(array( "file" => "snort.sh", "start" => "{$sample_before}{$start}{$sleep_before_final}{$sample_after}{$echo_usage}", "stop" => "/usr/bin/killall snort; killall snort2c" ) ); /* create snort configuration file */ create_snort_conf(); /* start snort service */ conf_mount_ro(); start_service("snort"); } function create_snort_conf() { global $config, $g; /* write out snort.conf */ $snort_conf_text = generate_snort_conf(); conf_mount_rw(); $conf = fopen("/usr/local/etc/snort/snort.conf", "w"); if(!$conf) { log_error("Could not open /usr/local/etc/snort/snort.conf for writing."); exit; } fwrite($conf, $snort_conf_text); fclose($conf); conf_mount_ro(); } function snort_deinstall() { $text_ww = "*/60\t* \t 1\t *\t *\t root\t /usr/bin/nice -n20 /usr/local/pkg/snort_check_for_rule_updates.php"; $filenamea = "/etc/crontab"; /* remove auto rules update helper */ remove_text_from_file($filenamea, $text_ww); /* remove custom sysctl */ remove_text_from_file("/etc/sysctl.conf", "sysctl net.bpf.bufsize=20480"); /* decrease bpf buffers back to 4096, from 20480 */ exec("/sbin/sysctl net.bpf.bufsize=4096"); exec("/usr/bin/killall snort"); sleep(5); exec("/usr/bin/killall -9 snort"); exec("rm -f /usr/local/etc/rc.d/snort*"); exec("rm -rf /usr/local/etc/snort*"); exec("cd /var/db/pkg && pkg_delete `ls | grep snort`"); exec("/usr/bin/killall -9 snort"); exec("/usr/bin/killall snort"); } function generate_snort_conf() { global $config, $g; conf_mount_rw(); /* obtain external interface */ /* XXX: make multi wan friendly */ $snort_ext_int = $config['installedpackages']['snort']['config'][0]['iface_array'][0]; $snort_config_pass_thru = $config['installedpackages']['snortadvanced']['config'][0]['configpassthru']; /* add auto update scripts to /etc/crontab */ $text_ww = "*/60\t* \t 1\t *\t *\t root\t /usr/bin/nice -n20 /usr/local/pkg/snort_check_for_rule_updates.php"; $filenamea = "/etc/crontab"; remove_text_from_file($filenamea, $text_ww); add_text_to_file($filenamea, $text_ww); exec("killall -HUP cron"); /* should we install a automatic update crontab entry? */ $automaticrulesupdate = $config['installedpackages']['snort']['config'][0]['automaticrulesupdate']; /* if user is on pppoe, we really want to use ng0 interface */ if($config['interfaces'][$snort_ext_int]['ipaddr'] == "pppoe") $snort_ext_int = "ng0"; /* set the snort performance model */ if($config['installedpackages']['snort']['config'][0]['performance']) $snort_performance = $config['installedpackages']['snort']['config'][0]['performance']; else $snort_performance = "ac-bnfa"; /* open snort2c's whitelist for writing */ $whitelist = fopen("/var/db/whitelist", "w"); if(!$whitelist) { log_error("Could not open /var/db/whitelist for writing."); return; } /* build an interface array list */ $int_array = array('lan'); for ($j = 1; isset ($config['interfaces']['opt' . $j]); $j++) if(isset($config['interfaces']['opt' . $j]['enable'])) if(!$config['interfaces']['opt' . $j]['gateway']) $int_array[] = "opt{$j}"; /* if user has defined a custom ssh port, use it */ if($config['system']['ssh']['port']) $ssh_port = $config['system']['ssh']['port']; else $ssh_port = "22"; /* iterate through interface list and write out whitelist items * and also compile a home_net list for snort. */ foreach($int_array as $int) { /* calculate interface subnet information */ $ifcfg = &$config['interfaces'][$int]; $subnet = gen_subnet($ifcfg['ipaddr'], $ifcfg['subnet']); $subnetmask = gen_subnet_mask($ifcfg['subnet']); if($subnet == "pppoe" or $subnet == "dhcp") { $subnet = find_interface_ip("ng0"); if($subnet) $home_net .= "{$subnet} "; } else { if ($subnet) if($ifcfg['subnet']) $home_net .= "{$subnet}/{$ifcfg['subnet']} "; } } /* add all WAN ips to the whitelist */ $wan_if = get_real_wan_interface(); $ip = find_interface_ip($wan_if); if($ip) $home_net .= "{$ip} "; /* Add Gateway on WAN interface to whitelist (For RRD graphs) */ $int = convert_friendly_interface_to_real_interface_name("WAN"); $gw = get_interface_gateway($int); if($gw) $home_net .= "{$gw} "; /* Add DNS server for WAN interface to whitelist */ $dns_servers = get_dns_servers(); foreach($dns_servers as $dns) { if($dns) $home_net .= "{$dns} "; } /* Add loopback to whitelist (ftphelper) */ $home_net .= "127.0.0.1 "; /* iterate all vips and add to whitelist */ if($config['virtualip']) foreach($config['virtualip']['vip'] as $vip) if($vip['subnet']) $home_net .= $vip['subnet'] . " "; if($config['installedpackages']['snortwhitelist']) foreach($config['installedpackages']['snortwhitelist']['config'] as $snort) if($snort['ip']) $home_net .= $snort['ip'] . " "; /* write out whitelist, convert spaces to carriage returns */ $whitelist_home_net = str_replace(" ", " ", $home_net); $whitelist_home_net = str_replace(" ", "\n", $home_net); /* make $home_net presentable to snort */ $home_net = trim($home_net); $home_net = str_replace(" ", ",", $home_net); $home_net = "[{$home_net}]"; /* foreach through whitelist, writing out to file */ $whitelist_split = split("\n", $whitelist_home_net); foreach($whitelist_split as $wl) if(trim($wl)) fwrite($whitelist, trim($wl) . "\n"); /* should we whitelist vpns? */ $whitelistvpns = $config['installedpackages']['snort']['config'][0]['whitelistvpns']; /* grab a list of vpns and whitelist if user desires */ if($whitelistvpns) { $vpns_list = get_vpns_list(); $whitelist_vpns = split(" ", $vpns_list); foreach($whitelist_split as $wl) if(trim($wl)) fwrite($whitelist, trim($wl) . "\n"); } /* close file */ fclose($whitelist); /* generate rule sections to load */ $enabled_rulesets = $config['installedpackages']['snort']['rulesets']; if($enabled_rulesets) { $selected_rules_sections = ""; $enabled_rulesets_array = split("\|\|", $enabled_rulesets); foreach($enabled_rulesets_array as $enabled_item) $selected_rules_sections .= "include \$RULE_PATH/{$enabled_item}\n"; } conf_mount_ro(); /* build snort configuration file */ $snort_conf_text = << \ cmd_validity STRU < char FRP > \ cmd_validity ALLO < int [ char R int ] > \ cmd_validity TYPE < { char AE [ char NTC ] | char I | char L [ number ] } > \ cmd_validity MDTM < [ date nnnnnnnnnnnnnn[.n[n[n]]] ] string > \ cmd_validity PORT < host_port > preprocessor ftp_telnet_protocol: ftp client default \ max_resp_len 100 preprocessor SMTP: \ ports { 25 465 691 } \ inspection_type stateful \ normalize cmds \ valid_cmds { MAIL RCPT HELP HELO ETRN EHLO EXPN VRFY ATRN SIZE BDAT DEBUG EMAL ESAM ESND ESOM EVFY IDENT NOOP RSET SEND SAML SOML AUTH TURN ETRN PIPELINING \ CHUNKING DATA DSN RSET QUIT ONEX QUEU STARTTLS TICK TIME TURNME VERB X-EXPS X-LINK2STATE XADR XAUTH XCIR XEXCH50 XGEN XLICENSE XQUEU XSTA XTRN XUSR } \ normalize_cmds { MAIL RCPT HELP HELO ETRN EHLO EXPN VRFY ATRN SIZE BDAT DEBUG EMAL ESAM ESND ESOM EVFY IDENT NOOP RSET SEND SAML SOML AUTH TURN ETRN \ PIPELINING CHUNKING DATA DSN RSET QUIT ONEX QUEU STARTTLS TICK TIME TURNME VERB X-EXPS X-LINK2STATE XADR XAUTH XCIR XEXCH50 XGEN XLICENSE XQUEU XSTA XTRN XUSR } \ max_header_line_len 1000 \ max_response_line_len 512 \ alt_max_command_line_len 260 { MAIL } \ alt_max_command_line_len 300 { RCPT } \ alt_max_command_line_len 500 { HELP HELO ETRN EHLO } \ alt_max_command_line_len 255 { EXPN VRFY ATRN SIZE BDAT DEBUG EMAL ESAM ESND ESOM EVFY IDENT NOOP RSET } \ alt_max_command_line_len 246 { SEND SAML SOML AUTH TURN ETRN PIPELINING CHUNKING DATA DSN RSET QUIT ONEX } \ alt_max_command_line_len 246 { QUEU STARTTLS TICK TIME TURNME VERB X-EXPS X-LINK2STATE XADR } \ alt_max_command_line_len 246 { XAUTH XCIR XEXCH50 XGEN XLICENSE XQUEU XSTA XTRN XUSR } \ xlink2state { enable } #sf Portscan preprocessor sfportscan: proto { all } \ scan_type { all } \ sense_level { low } \ ignore_scanners { \$HOME_NET } preprocessor dcerpc: \ autodetect \ max_frag_size 3000 \ memcap 100000 preprocessor dns: ports { 53 } enable_rdata_overflow #Output plugins #output database: alert output alert_syslog: LOG_AUTH LOG_ALERT LOG_CONS LOG_NDELAY LOG_PERROR LOG_PID output alert_unified: filename alert #Required files include /usr/local/etc/snort/classification.config include /usr/local/etc/snort/reference.config # Include any thresholding or suppression commands. See threshold.conf in the # include threshold.conf # Snort user pass through configuration {$snort_config_pass_thru} #Rulesets, all optional {$selected_rules_sections} EOD; return $snort_conf_text; } /* check downloaded text from snort.org to make sure that an error did not occur * for example, if you are not a premium subscriber you can only download rules * so often, etc. */ function check_for_common_errors($filename) { global $snort_filename, $snort_filename_md5, $console_mode; ob_flush(); $contents = file_get_contents($filename); if(stristr($contents, "You don't have permission")) { if(!$console_mode) { update_all_status("An error occured while downloading {$filename}."); hide_progress_bar_status(); } else { log_error("An error occured. Scroll down to inspect it's contents."); echo "An error occured. Scroll down to inspect it's contents."; } if(!$console_mode) { update_output_window(strip_tags("$contents")); } else { $contents = strip_tags($contents); log_error("Error downloading snort rules: {$contents}"); echo "Error downloading snort rules: {$contents}"; } scroll_down_to_bottom_of_page(); exit; } } /* force browser to scroll all the way down */ function scroll_down_to_bottom_of_page() { global $snort_filename, $console_mode; ob_flush(); if(!$console_mode) echo "\n"; } /* ensure downloaded file looks sane */ function verify_downloaded_file($filename) { global $snort_filename, $snort_filename_md5, $console_mode; ob_flush(); if(filesize($filename)<9500) { if(!$console_mode) { update_all_status("Checking {$filename}..."); check_for_common_errors($filename); } } update_all_status("Verifying {$filename}..."); if(!file_exists($filename)) { if(!$console_mode) { update_all_status("Could not fetch snort rules ({$filename}). Check oinkid key and dns and try again."); hide_progress_bar_status(); } else { log_error("Could not fetch snort rules ({$filename}). Check oinkid key and dns and try again."); echo "Could not fetch snort rules ({$filename}). Check oinkid key and dns and try again."; } exit; } update_all_status("Verifyied {$filename}."); } /* extract rules */ function extract_snort_rules_md5($tmpfname) { global $snort_filename, $snort_filename_md5, $console_mode; ob_flush(); if(!$console_mode) { $static_output = gettext("Extracting snort rules..."); update_all_status($static_output); } if(!is_dir("/usr/local/etc/snort/rules/")) mkdir("/usr/local/etc/snort/rules/"); $cmd = "/usr/bin/tar xzf {$tmpfname}/{$snort_filename} -C /usr/local/etc/snort/ rules/"; $handle = popen("{$cmd} 2>&1", 'r'); while(!feof($handle)) { $buffer = fgets($handle); update_output_window($buffer); } pclose($handle); if(!$console_mode) { $static_output = gettext("Snort rules extracted."); update_all_status($static_output); } else { log_error("Snort rules extracted."); echo "Snort rules extracted."; } } /* verify MD5 against downloaded item */ function verify_snort_rules_md5($tmpfname) { global $snort_filename, $snort_filename_md5, $console_mode; ob_flush(); if(!$console_mode) { $static_output = gettext("Verifying md5 signature..."); update_all_status($static_output); } $md5 = file_get_contents("{$tmpfname}/{$snort_filename_md5}"); $file_md5_ondisk = `/sbin/md5 {$tmpfname}/{$snort_filename} | /usr/bin/awk '{ print $4 }'`; if($md5 <> $file_md5_ondisk) { if(!$console_mode) { $static_output = gettext("snort rules: md5 signature of rules mismatch."); update_all_status($static_output); hide_progress_bar_status(); } else { log_error("snort rules: md5 signature of rules mismatch."); echo "snort rules: md5 signature of rules mismatch."; } exit; } } /* hide progress bar */ function hide_progress_bar_status() { global $snort_filename, $snort_filename_md5, $console_mode; ob_flush(); if(!$console_mode) echo "\n"; } /* update both top and bottom text box during an operation */ function update_all_status($status) { global $snort_filename, $snort_filename_md5, $console_mode; ob_flush(); if(!$console_mode) { update_status($status); update_output_window($status); } } /* obtain alert description for an ip address */ function get_snort_alert($ip) { global $snort_alert_file_split, $snort_config; if(!file_exists("/var/log/snort/alert")) return; if(!$snort_config) $snort_config = read_snort_config_cache(); if($snort_config[$ip]) return $snort_config[$ip]; if(!$snort_alert_file_split) $snort_alert_file_split = split("\n", file_get_contents("/var/log/snort/alert")); foreach($snort_alert_file_split as $fileline) { if (preg_match("/\[\*\*\] (\[.*\]) (.*) (\[\*\*\])/", $fileline, $matches)) $alert_title = $matches[2]; if (preg_match("/(\b(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\b)/", $fileline, $matches)) $alert_ip = $matches[0]; if($alert_ip == $ip) { if(!$snort_config[$ip]) $snort_config[$ip] = $alert_title; return $alert_title; } } return "n/a"; } function make_clickable($buffer) { global $config, $g; /* if clickable urls is disabled, simply return buffer back to caller */ $clickablalerteurls = $config['installedpackages']['snort']['config'][0]['oinkmastercode']; if(!$clickablalerteurls) return $buffer; $buffer = eregi_replace("(^|[ \n\r\t])((http(s?)://)(www\.)?([a-z0-9_-]+(\.[a-z0-9_-]+)+)(/[^/ \n\r]*)*)","\\1\\2", $buffer); $buffer = eregi_replace("(^|[ \n\r\t])((ftp://)(www\.)?([a-z0-9_-]+(\.[a-z0-9_-]+)+)(/[^/ \n\r]*)*)","\\1\\2", $buffer); $buffer = eregi_replace("([a-z_-][a-z0-9\._-]*@[a-z0-9_-]+(\.[a-z0-9_-]+)+)","\\1", $buffer); $buffer = eregi_replace("(^|[ \n\r\t])(www\.([a-z0-9_-]+(\.[a-z0-9_-]+)+)(/[^/ \n\r]*)*)","\\1\\2", $buffer); $buffer = eregi_replace("(^|[ \n\r\t])(ftp\.([a-z0-9_-]+(\.[a-z0-9_-]+)+)(/[^/ \n\r]*)*)","\\1\\2", $buffer); return $buffer; } function read_snort_config_cache() { global $g, $config, $snort_config; if($snort_config) return $snort_config; if(file_exists($g['tmp_path'] . '/snort_config.cache')) { $snort_config = unserialize(file_get_contents($g['tmp_path'] . '/snort_config.cache')); return $snort_config; } return; } function write_snort_config_cache($snort_config) { global $g, $config; conf_mount_rw(); $configcache = fopen($g['tmp_path'] . '/snort_config.cache', "w"); if(!$configcache) { log_error("Could not open {$g['tmp_path']}/snort_config.cache for writing."); return false; } fwrite($configcache, serialize($snort_config)); fclose($configcache); conf_mount_ro(); return true; } function snort_advanced() { global $g, $config; sync_package_snort(); } ?>