Re: getsockopt() with IP_PKTINFO not working?
On Wed, Dec 20, 2000 at 05:44:34PM +0100, Cord Seele wrote: > I am trying to get the destination address of an incoming udp packet > with getsockopt(). > According to the man pages flag IP_PKTINFO should do that. But it > doesn't work: > > struct in_pktinfo pktinfo; > socklen_t optlen; > struct in_addr local_addr; > > optlen=(socklen_t)sizeof(pktinfo); > syslog (LOG_ERR, "ERR %d", > getsockopt(fd, SOL_IP, IP_PKTINFO, , )); You're misreading the manpage. IP_PKTINFO just enables recvmsg() to pass ancillary messages that contain pktinfo structures. getsockopt IP_PKTINFO returns the state of the the IP_PKTINFO flag on the socket. So use setsockopt IP_PKTINFO to set the flag to true and then receive them using recvmsg(). -Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
Re: getsockopt() with IP_PKTINFO not working?
On Wed, Dec 20, 2000 at 05:44:34PM +0100, Cord Seele wrote: I am trying to get the destination address of an incoming udp packet with getsockopt(). According to the man pages flag IP_PKTINFO should do that. But it doesn't work: struct in_pktinfo pktinfo; socklen_t optlen; struct in_addr local_addr; optlen=(socklen_t)sizeof(pktinfo); syslog (LOG_ERR, "ERR %d", getsockopt(fd, SOL_IP, IP_PKTINFO, pktinfo, optlen)); You're misreading the manpage. IP_PKTINFO just enables recvmsg() to pass ancillary messages that contain pktinfo structures. getsockopt IP_PKTINFO returns the state of the the IP_PKTINFO flag on the socket. So use setsockopt IP_PKTINFO to set the flag to true and then receive them using recvmsg(). -Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] Please read the FAQ at http://www.tux.org/lkml/
