upnpDiscover( ) :"sendto: Operation not permitted" && getaddrinfo() error : “Bad value for ai_flags”
sendto: Operation not permitted
在miniupnpc -1.6 的sourcecode 中 有个upnpDiscover( )函数 是向多播地址地址 UPNP_MCAST_ADDR "239.255.255.250" ，端口为 PORT 1900的socket 发多播包，编译的可执行档 upnpc 在pc上运行良好：
[vinco@IPPBX-Server miniupnpc]$ ./upnpc-static -s
List of UPNP devices found on the network :
desc: http://172.16.1.115:2869/upnphost/udhisapi.dll?content=uuid:a8cfb97b-2b2b-4768-8d56-b96687b40899
st: upnp:rootdevice
UPnP device found. Is it an IGD ? : http://172.16.1.115:2869/
Trying to continue anyway
Local LAN ip address : 172.16.0.248
Connection Type :
Status : ôï¿, uptime=3219584368s, LastConnectionError :
Time started : Fri May 6 19:34:47 1910
MaxBitRateDown : 11201788 bps (11.2 Mbps) MaxBitRateUp 153932400 bps (153.9 Mbps)
GetExternalIPAddress() returned -3
ExternalIPAddress = Àô¿
Bytes: Sent: 4294967293 Recv: 4294967293
Packets: Sent: 4294967293 Recv: 4294967293
[vinco@IPPBX-Server miniupnpc]$
[vinco@IPPBX-Server miniupnpc]$ 但是一旦编译放到板子上运行，在sendto( )系统调用处就会出现令人头痛的 sendto: Operation not permitted：
# upnpc -s
Sending
M-SEARCH * HTTP/1.1
HOST: 239.255.255.250:1900
ST: urn:schemas-upnp-org:device:InternetGatewayDevice:1
MAN: "ssdp:discover"
MX: 2
host:239.255.255.250 port:1900
sendto: Operation not permitted
upnpDiscover-line 520
No IGD UPnP Device found on the network !
# 查看相应的iptables 信息(当然是filter表，OUTPUT chain啦)：
#
# iptables -nvL OUTPUT
Chain OUTPUT (policy ACCEPT 835 packets, 395K bytes)
pkts bytes target prot opt in out source destination
1 165 DROP all -- * eth2 0.0.0.0/0 239.255.255.250
#
# 发现了这坑爹的一幕，终于知道原因了。于是do as follow:
#
# iptables -D OUTPUT 1
# iptables -nvL OUTPUT
Chain OUTPUT (policy ACCEPT 919 packets, 453K bytes)
pkts bytes target prot opt in out source destination
#
# 确保将这条该死的drop规则去掉（或者修改为其他具体的规则），发现sento（）多播的问题解决了：
# upnpc -s
Sending
M-SEARCH * HTTP/1.1
HOST: 239.255.255.250:1900
ST: urn:schemas-upnp-org:device:InternetGatewayDevice:1
MAN: "ssdp:discover"
MX: 2
M-SEARCH Reply:
ST: urn:schemas-upnp-org:device:InternetGatewayDevice:1
Location: http://172.16.12.50:5431/dyndev/uuid:00191507-0023-2300-0715-19001907230000
List of UPNP devices found on the network :
desc: http://172.16.12.50:5431/dyndev/uuid:00191507-0023-2300-0715-19001907230000
st: urn:schemas-upnp-org:device:InternetGatewayDevice:1
getaddrinfo() error : Bad value for ai_flags
error getting XML description http://172.16.12.50:5431/dyndev/uuid:00191507-0023-2300-0715-19001907230000
No valid UPNP Internet Gateway Device found.
#
# 这里还有个坑爹问题，就是 getaddrinfo() error : Bad value for ai_flags 这个很邪恶问题。
在源代码 connecthostport.c 的connecthostport( ) 函数中有的是getaddrinfo( )(不是用gethostbyname( )，源码中有一个宏 USE_GETHOSTBYNAME 控制)， 同时用一个宏在hints初始化过程中控制ai_flags的赋值。的确有了这个AI_NUMERICSERV定义。
#ifdef AI_NUMERICSERV
hints.ai_flags = AI_NUMERICSERV;
#endif但是就是这个 ai_flags初始得有问题啊，干脆注释掉：
#ifdef AI_NUMERICSERV
// damn it:getaddrinfo() error : Bad value for ai_flags
//hints.ai_flags = AI_NUMERICSERV;
#endif板子上运行：
#
# upnpc -s
List of UPNP devices found on the network :
desc: http://172.16.12.50:5431/dyndev/uuid:00191507-0023-2300-0715-19001907230000
st: urn:schemas-upnp-org:device:InternetGatewayDevice:1
Found valid IGD : http://172.16.12.50:5431/uuid:00191507-0023-2300-0715-19001907230002/WANPPPConnection:1
Local LAN ip address : 172.16.15.55
Connection Type : IP_Routed
Status : Connected, uptime=55s, LastConnectionError :
Time started : Mon May 14 03:39:01 2012
MaxBitRateDown : 11068000 bps (11.0 Mbps) MaxBitRateUp 1120000 bps (1.1 Mbps)
ExternalIPAddress = 111.174.238.218
Bytes: Sent: 0 Recv: 0
Packets: Sent: 0 Recv: 0
#
#
# http://permalink.gmane.org/gmane.comp.web.privoxy.devel/10735 这个链接中有一种说法：
It seems that one or both of the flags AI_NUMERICSERV and AI_ADDRCONFIG
is/are defined but not actually supported.
To work around the problem you could try adding:
#undef AI_NUMERICSERV
#define AI_NUMERICSERV 0
below the line "#define MAX_LISTEN_BACKLOG 128" in jbsockets.c.
If it still doesn't work, add:
#undef AI_ADDRCONFIG
#define AI_ADDRCONFIG 0
and if it still fails use all four lines.
这个貌似也可以解决，但我没试过。