Date: Mon, 2 Apr 2001 20:45:16 +0300 From: Ruslan Ermilov <ru@FreeBSD.org> To: Alexander Leidinger <Alexander@leidinger.net> Cc: net@FreeBSD.org, isdn@FreeBSD.org Subject: Re: Recent interface/routing changes breaks on-demand PPP (+sppp) Message-ID: <20010402204516.A74854@sunbay.com> In-Reply-To: <200104021652.f32Gq1I02500@Magelan.Leidinger.net>; from Alexander@leidinger.net on Mon, Apr 02, 2001 at 06:52:00PM %2B0200 References: <20010331204534.B11966@sunbay.com> <200104021652.f32Gq1I02500@Magelan.Leidinger.net>
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--bg08WKrSYDhXBjb5 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Mon, Apr 02, 2001 at 06:52:00PM +0200, Alexander Leidinger wrote: > On 31 Mar, Ruslan Ermilov wrote: > > [-isdn CCed,] > > Dear -isdn readers, we are talking about the actual behavior of > -current, see -current and -net for the beginning of the discussion. > > >> >> If I use > >> >> route add default -interface isp1 > >> >> I wan't to have the packets routed trough isp1. I don't care about how > >> >> the routing table is held consistent, but I if the route is discarded > >> >> without my interaction it not only violates POLA, in this case it's > >> >> prohibits a valid use of the -interface feature (dial on demand via sppp > >> >> is broken at the moment). > >> >> > >> > OK, finally got it. When the interface goes down, the address is still > >> > valid, and there is no reason to delete (static?) routes that use this > >> > address, but the new code does. I was confused by the code comment below > >> > >> I didn't have a static IP address. The only static thing in this context > >> is the interface the defaultroute is assigned to. At every > >> dial-on-demand I get another IP. > >> > > Well, if address is deleted from an interface, all routes that use it > > will be invalidated (deleted) to avoid using the wrong address. This > > patch only fixes interface down/up case, when address does not change. > > If "isp1" is a valid address in this context: it doesn't change. > Nope, "isp1" is not an address, it is the pointer to an interface. Routing table entry has both pointer to an interface, and a pointer to one of its addresses. That is what you see in the output from ``route -vn get default'' command, as IFP and IFA sockaddrs. > Here a little bit of cut&paste (your "#if 0" patch is applied) > which perhaps gives you a hint what I have here: > ---snip--- > (3) netchild@ttyp1 % ifconfig isp1 > isp1: flags=a010<POINTOPOINT,LINK1,MULTICAST> mtu 1500 > inet 0.0.0.0 --> 0.0.0.1 netmask 0xffff0000 > ether 00:00:00:00:00:00 > > (4) netchild@ttyp1 % netstat -rn > Routing tables > > Internet: > Destination Gateway Flags Refs Use Netif Expire > default 0:0:0:0:0:0 USc 0 1 isp1 > 0.0.0.1 0.0.0.0 UH 0 0 isp1 > 127.0.0.1 127.0.0.1 UH 2 4613 lo0 > 192.168.1 link#1 UC 1 0 ed0 => > > (5) netchild@ttyp1 % isdn-up # this is a SUID wrapper for "ifconfig isp1 up" > > (6) netchild@ttyp1 % ifconfig isp1 > isp1: flags=a011<UP,POINTOPOINT,LINK1,MULTICAST> mtu 1500 > inet 0.0.0.0 --> 0.0.0.1 netmask 0xffff0000 > ether 00:00:00:00:00:00 > > (7) netchild@ttyp1 % netstat -rn > Routing tables > > Internet: > Destination Gateway Flags Refs Use Netif Expire > default 0:0:0:0:0:0 USc 0 1 isp1 > 0.0.0.1 0.0.0.0 UH 0 0 isp1 > 0.0.0.2 0.0.0.0 UH 0 0 isp0 > 127.0.0.1 127.0.0.1 UH 2 4613 lo0 > 192.168.1 link#1 UC 1 0 ed0 => > ---snip--- > > isp1 gets a new IP address after the ppp negotiation of sppp/isdnd. > 0.0.0.0 -> 0.0.0.1 uses a documented hack in the i4b stack which > discards the first packet to don't let go a packet with a wrong address > (0.0.0.0) out of the computer. After a timeout or an "ifconfig isp1 > down" it hangs up and the dynamic IP address of isp1 get's replaced by > 0.0.0.0 again. The actual behavior of -current breaks the documented way > of enabling dial-on-demand with sppp/isdnd. > (To -isdn readers: after the first "ifconfig isp1 down" the defaultroute > vanishes, after a manual "route add default -interface isp1" the route > stays even with subsequent "ifconfig isp1 down", doing an additional > "route add ..." is annoying, needs additional privileges and violates > POLA) > OK, we fixed the "ifconfig down" case already. The attached patch alters inet routing code so that it does not delete routes with the "default" source address of 0.0.0.0; ip_output() will take care of choosing the right address. Please let me know if it works for you. Cheers, -- Ruslan Ermilov Oracle Developer/DBA, ru@sunbay.com Sunbay Software AG, ru@FreeBSD.org FreeBSD committer, +380.652.512.251 Simferopol, Ukraine http://www.FreeBSD.org The Power To Serve http://www.oracle.com Enabling The Information Age --bg08WKrSYDhXBjb5 Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename=p Index: in_rmx.c =================================================================== RCS file: /home/ncvs/src/sys/netinet/in_rmx.c,v retrieving revision 1.39 diff -u -p -u -r1.39 in_rmx.c --- in_rmx.c 2001/03/19 09:16:16 1.39 +++ in_rmx.c 2001/04/02 17:25:57 @@ -416,6 +416,9 @@ in_ifadown(struct ifaddr *ifa) if (ifa->ifa_addr->sa_family != AF_INET) return 1; + if (((struct sockaddr_in *)ifa->ifa_addr)->sin_addr.s_addr == INADDR_ANY) + return 0; + arg.rnh = rnh = rt_tables[AF_INET]; arg.ifa = ifa; rnh->rnh_walktree(rnh, in_ifadownkill, &arg); --bg08WKrSYDhXBjb5-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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