我想删除必须和联系字段为空的sip数据包。
INVITE sip:******************* SIP/2.0
Record-Route:
Via: SIP/2.0/UDP *********;branch=z9hG4bK0e44.f7bd2db2.0
Via: SIP/2.0/UDP ************:5060;received=*********;branch=z9hG4bK78f0df76;rport=1122
Max-Forwards: 69
From: "1014" ;tag=as2fff3730
To:
Contact:
Call-ID: **********@*********
CSeq: 103 INVITE
User-Agent: Asterisk PBX 1.6.2.9-2ubuntu2.1
Date: Wed, 09 Oct 2013 15:16:20 GMT
Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER, SUBSCRIBE, NOTIFY, INFO
Supported: replaces, timer
Content-Type: application/sdp
Content-Length: 311
我正在使用opensips（处理sip数据包的代码在opensips.cfg文件中）。我怎样才能识别这些数据包并丢弃它们？
编辑：相应的解析消息是：
Oct 9 17:16:00 voip /usr/local/sbin/opensips[32325]: ERROR:core:parse_first_line: bad request first line
Oct 9 17:16:00 voip /usr/local/sbin/opensips[32325]: ERROR:core:parse_first_line: at line 0 char 42:
Oct 9 17:16:00 voip /usr/local/sbin/opensips[32325]: ERROR:core:parse_first_line: parsed so far: INVITE sip:***********************:5060
Oct 9 17:16:00 voip /usr/local/sbin/opensips[32325]: INFO:core:parse_first_line: bad message
> sendrecv 0-16lephone-event/8000 *************SUBSCRIBE, NOTIFY, INFOg: message=<INVITE sip:*************:5060 SIP/2.0
Oct 9 17:16:00 voip /usr/local/sbin/opensips[32325]: ERROR:core:receive_msg: parse_msg failed
Oct 9 17:16:04 voip /usr/local/sbin/opensips[32303]: ERROR:core:parse_first_line: bad request first line
Oct 9 17:16:04 voip /usr/local/sbin/opensips[32303]: ERROR:core:parse_first_line: at line 0 char 42:
Oct 9 17:16:04 voip /usr/local/sbin/opensips[32303]: ERROR:core:parse_first_line: parsed so far: INVITE sip:****************:5060
Oct 9 17:16:04 voip /usr/local/sbin/opensips[32303]: INFO:core:parse_first_line: bad message
> sendrecv 0-16lephone-event/*******************SUBSCRIBE, NOTIFY, INFOg: message=<INVITE sip:*****************:5060 SIP/2.0
Oct 9 17:16:04 voip /usr/local/sbin/opensips[32303]: ERROR:core:receive_msg: parse_msg failed