On Sun, Apr 24, 2011 at 12:49:46PM +0100, Stuart Henderson wrote: > On 2011/04/24 10:42, Claudio Jeker wrote: > > On Sat, Apr 23, 2011 at 08:58:12PM +0000, Stuart Henderson wrote: > > > On 2011-04-23, Henning Brauer <lists-openbsdpo...@bsws.de> wrote: > > > > * Stuart Henderson <s...@spacehopper.org> [2011-04-23 14:41]: > > > >> Should we do this or should we rethink allowing sockets to be > > > >> bound to broadcast IP addresses? > > > > > > > > i have no idea. and that seems to be common for all of us. i really > > > > dunno. anybody? > > > > > > > > > > Unless there are objections I'll commit my samba diff tomorrow, > > > it can always come out again if anything else changes. > > > > What is this socket used for? You can not send a packet out of that > > socket. I guess it is a UDP socket that should pickup the broadcast hellos > > that flood windows infested networks. > > Yes, exactly. > > > Our network stack will deliver broadcast datagram to all IP RAW and all > > UDP dgram sockets that match and are bound to 0.0.0.0 or ::. > > > > /* > > * Deliver a multicast or broadcast datagram to *all* sockets > > * for which the local and remote addresses and ports match > > * those of the incoming datagram. This allows more than > > * one process to receive multi/broadcasts on the same port. > > > > Now there is this bit of code in the loop as well: > > if (inp->inp_laddr.s_addr != INADDR_ANY) { > > if (inp->inp_laddr.s_addr != ip->ip_dst.s_addr) > > continue; > > } > > > > So it may make sense to bind to a specific broadcast addr for SOCK_DGRAM > > and SOCK_RAW AF_INET socks. In that case you only receive packets that are > > sent to the network specific broadcast (this does not work for > > packets sent to 255.255.255.255 on that LAN segment) > > That would look something like this horror.. > > Index: in_pcb.c > =================================================================== > RCS file: /cvs/src/sys/netinet/in_pcb.c,v > retrieving revision 1.116 > diff -u -p -r1.116 in_pcb.c > --- in_pcb.c 19 Apr 2011 03:47:29 -0000 1.116 > +++ in_pcb.c 24 Apr 2011 11:31:56 -0000 > @@ -276,8 +276,12 @@ in_pcbbind(v, nam, p) > } else if (sin->sin_addr.s_addr != INADDR_ANY) { > sin->sin_port = 0; /* yech... */ > if (!(so->so_options & SO_BINDANY) && > - in_iawithaddr(sin->sin_addr, > - inp->inp_rtableid) == NULL) > + (ifa_ifwithaddr(sintosa(&sin), > + inp->inp_rtableid) == NULL) && > + (so->so_type != SOCK_DGRAM) && > + (so->so_type != SOCK_RAW) && > + (in_iawithaddr(sin->sin_addr, > + inp->inp_rtableid) == NULL)) > return (EADDRNOTAVAIL); > } > if (lport) {
I would prefer to split this monstrosity into multiple if statements. Since this is totaly unreadable but I guess we want something like this. We could call in_broadcast(sin->sin_addr, NULL) instead of in_iawithaddr() to make the code more clear. -- :wq Claudio