分享下笔者最近编写的 kamailio 路由脚本

1. 不用 rr 模块，因为有些 sip 协议栈不支持 rr 头
2. 处理 sip 注册直接回 200 OK，这部分目前不是重点
3. 更换 contact 头，换成 kamailio 自己
4. 目前只支持 sip transport 为 udp，以后可能支持 tcp，tls 等

测试环境为：

1. kamailio 版本为 5.8.1
2. kamailio ip 为 192.168.43.135
3. fs ip为 192.168.43.203
4. microsip ip 为 192.168.43.68，修改 microsip.ini，sourcePort=5060
5. fs 呼叫 kamailio, 后者 relay 到 microsip 的 5060 端口
6. microsip 呼叫 kamailio, 后者 relay 到 fs 的 5080 端口

内行看门道，可重点关注下面几个路由块：

• route[INVITE]
• onreply_route[MANAGE_REPLY] 
• route[WITHINDLG] 

下面是完整的路由脚本：

#!substdef "!KAM_IP!192.168.43.135!g"
#!substdef "!KAM_PORT!5060!g"#!substdef "!FS!sip:192.168.43.203:5080!g"
#!substdef "!MICROSIP!sip:192.168.43.68:5060!g"# - flags
#   FLT_ - per transaction (message) flags
#!define FLT_ACC 1
#!define FLT_ACCMISSED 2
#!define FLT_ACCFAILED 3
#!define FLT_NATS 5#	FLB_ - per branch flags
#!define FLB_NATB 6
#!define FLB_NATSIPPING 7debug=2
log_stderror=no
memdbg=5
memlog=5log_facility=LOG_LOCAL0
log_prefix="{$mt $hdr(CSeq) $ci} "children=8# disable_tcp=yes
# tcp_children=8
# auto_aliases=no
# alias="sip.mydomain.com"listen=udp:KAM_IP:KAM_PORT
listen=tcp:KAM_IP:KAM_PORTtcp_connection_lifetime=3605
tcp_max_connections=2048
tcp_accept_no_cl=yes
enable_sctp=no# mpath="/usr/local/lib/kamailio/modules/"loadmodule "xhttp.so"
loadmodule "jsonrpcs.so"
loadmodule "kex.so"
loadmodule "corex.so"
loadmodule "tm.so"
loadmodule "tmx.so"
loadmodule "sl.so"
#loadmodule "rr.so"
loadmodule "pv.so"
loadmodule "maxfwd.so"
loadmodule "usrloc.so"
loadmodule "registrar.so"
loadmodule "textops.so"
loadmodule "textopsx.so"
loadmodule "siputils.so"
loadmodule "xlog.so"
loadmodule "sanity.so"
loadmodule "ctl.so"
loadmodule "cfg_rpc.so"
loadmodule "counters.so"
#loadmodule "auth_db.so"
loadmodule "nathelper.so"
#loadmodule "rtpengine.so"loadmodule "htable.so"modparam("jsonrpcs", "pretty_format", 1)
# modparam("jsonrpcs", "fifo_name", "/run/kamailio/kamailio_rpc.fifo")
# modparam("jsonrpcs", "dgram_socket", "/run/kamailio/kamailio_rpc.sock")
modparam("jsonrpcs", "transport", 7)# modparam("ctl", "binrpc", "unix:/run/kamailio/kamailio_ctl")modparam("sanity", "autodrop", 0)modparam("tm", "failure_reply_mode", 3)
modparam("tm", "fr_timer", 30000)
modparam("tm", "fr_inv_timer", 120000)modparam("registrar", "method_filtering", 1)
# modparam("registrar", "append_branches", 0)
# modparam("registrar", "max_contacts", 10)
modparam("registrar", "max_expires", 3600)
modparam("registrar", "gruu_enabled", 0)
modparam("registrar", "use_path", 1)
modparam("registrar", "path_mode", 0)modparam("usrloc", "timer_interval", 60)
modparam("usrloc", "timer_procs", 1)
modparam("usrloc", "use_domain", 0)#modparam("usrloc", "db_url", DBURL)
modparam("usrloc", "db_mode", 0)#modparam("auth_db", "db_url", DBURL)
#modparam("auth_db", "calculate_ha1", yes)
#modparam("auth_db", "password_column", "password")
#modparam("auth_db", "load_credentials", "")
#modparam("auth_db", "use_domain", 0)#modparam("rtpengine", "rtpengine_sock", "udp:127.0.0.1:2223")# ----- nathelper params -----
modparam("nathelper", "natping_interval", 30)
modparam("nathelper", "ping_nated_only", 1)
modparam("nathelper", "sipping_bflag", FLB_NATSIPPING)
modparam("nathelper", "sipping_from", "sip:pinger@kamailio.org")modparam("nathelper|registrar", "received_avp", "$avp(RECEIVED)")
modparam("usrloc", "nat_bflag", FLB_NATB)request_route {route(REQINIT);route(NATDETECT);# CANCEL processingif (is_method("CANCEL")) {if (t_check_trans()) {route(RELAY);}exit;}if (!is_method("ACK")) {if(t_precheck_trans()) {t_check_trans();exit;}t_check_trans();}route(WITHINDLG);route(AUTH);remove_hf("Route");route(PRESENCE);route(REGISTRAR);if (is_method("OPTIONS")) {sl_send_reply("200", "OK");exit;}if ($rU==$null) {sl_send_reply("484", "Address Incomplete");exit;}if (is_method("INVITE")) {route(INVITE);exit;}sl_send_reply("501", "Not Implemented ");return;
}route[RELAY] {if (is_method("INVITE|BYE|SUBSCRIBE|UPDATE")) {if(!t_is_set("branch_route")) t_on_branch("MANAGE_BRANCH");}if (is_method("INVITE|SUBSCRIBE|UPDATE")) {if(!t_is_set("onreply_route")) t_on_reply("MANAGE_REPLY");}if (is_method("INVITE")) {if(!t_is_set("failure_route")) t_on_failure("MANAGE_FAILURE");}if (!t_relay()) {sl_reply_error();}exit;
}route[REQINIT] {set_reply_no_connect();force_rport();if (!mf_process_maxfwd_header("10")) {sl_send_reply("483", "Too Many Hops");exit;}if(!sanity_check("17895", "7")) {xlog("Malformed SIP request from $si:$sp\n");exit;}
}route[WITHINDLG] {if (!has_totag()) return;if ($(ru{uri.param,lm}) =~ "ua") {$var(host) = $(ru{uri.param,lhst});xlog("WITHINDLG|$var(host)\n");$var(host)=$(var(host){s.decode.base64t});$du = $var(host);xlog("WITHINDLG|du=$var(host)\n");$var(new) = $(ru{re.subst,/^(sip:.*);lhst=.*/\1/});$ru = $var(new);xlog("WITHINDLG|ru=$var(new)\n");route(RELAY);}exit;
}route[REGISTRAR] {if (!is_method("REGISTER")) return;sl_send_reply("200", "OK");exit;
}# Presence server processing
route[PRESENCE] {if(!is_method("PUBLISH|SUBSCRIBE")) return;sl_send_reply("404", "Not here");exit;
}route[AUTH] {return;
}route[NATDETECT] {//if (nat_uac_test("19")) {//	if (is_method("REGISTER")) {//		fix_nated_register();//	} else {//		if(is_first_hop()) {//			set_contact_alias();//		}//	}//	setflag(FLT_NATS);//}return;
}route[NATMANAGE] {//if (is_request()) {//	if(has_totag()) {//		if(check_route_param("nat=yes")) {//			setbflag(FLB_NATB);//		}//	}//}if (!(isflagset(FLT_NATS) || isbflagset(FLB_NATB))) return;//if(nat_uac_test("8")) {//	rtpengine_manage("SIP-source-address replace-origin replace-session-connection");//} else {//	rtpengine_manage("replace-origin replace-session-connection");//}//if (is_request()) {//	if (!has_totag()) {//		if(t_is_branch_route()) {//			add_rr_param(";nat=yes");//		}//	}//}if (is_reply()) {if(isbflagset(FLB_NATB)) {if(is_first_hop())set_contact_alias();}}if(isbflagset(FLB_NATB)) {# no connect message in a dialog involving NAT traversalif (is_request()) {if(has_totag()) {set_forward_no_connect();}}}return;
}# URI update for dialog requests
route[DLGURI] {if(!isdsturiset()) {handle_ruri_alias();}return;
}event_route[xhttp:request] {set_reply_close();set_reply_no_connect();if(src_ip!=127.0.0.1) {xhttp_reply("403", "Forbidden", "text/html","<html><body>Not allowed from $si</body></html>");exit;}if ($hu =~ "^/RPC") {jsonrpc_dispatch();exit;}xhttp_reply("200", "OK", "text/html","<html><body>Wrong URL $hu</body></html>");exit;
}branch_route[MANAGE_BRANCH] {xdbg("new branch [$T_branch_idx] to $ru\n");route(NATMANAGE);return;
}reply_route {if(!sanity_check("17604", "6")) {xlog("Malformed SIP response from $si:$sp\n");drop;}return;
}onreply_route[MANAGE_REPLY] {xinfo("incoming reply|$rm|$rs|$ct\n");if($rm == "INVITE" && status=~"[12][0-9][0-9]" && is_present_hf("Contact")) {$var(user) = $(sel(contact.uri.user));remove_hf("Contact");$var(host) = $(sut{s.encode.base64t});append_hf("Contact: <sip:$var(user)@KAM_IP:KAM_PORT;transport=udp;lhst=$var(host);lm=uas>\r\n", "CSeq");route(NATMANAGE);}return;
}failure_route[MANAGE_FAILURE] {route(NATMANAGE);if (t_is_canceled()) exit;return;
}route[INVITE] {if ($ua =~ "FreeSWITCH") {xlog("fs call microsip\n");$du = "MICROSIP";} else {xlog("microsip call fs\n");$du = "FS";}$var(user) = $(sel(contact.uri.user));remove_hf("Contact");$var(host) = $(sut{s.encode.base64t});append_hf("Contact: <sip:$var(user)@KAM_IP:KAM_PORT;transport=udp;lhst=$var(host);lm=uac>\r\n", "CSeq");route(RELAY);exit;
}

当然 OpenSIPS 有拓扑隐藏模块，UA 看不到 rr 头，工作的很好