Re: [RFC][2.4 PATCH] source address selection for ARP requests
From: Willy Tarreau <hidden>
Date: 2003-08-20 22:29:19
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On Wed, Aug 20, 2003 at 02:47:11PM -0700, David S. Miller wrote:
On Wed, 20 Aug 2003 23:34:43 +0200 Willy Tarreau [off-list ref] wrote:quoted
+ if (in_dev == NULL) + return;A NULL in_dev is what you'll see if no addresses are assigned to the interface, therefore you must treat this case similarly.
OK, that's fine. It is what I wanted to test with in_dev->ifa_list==NULL. I don't know if I must keep the test or not (anyway, it doesn't hurt, this isn't a fast path). Better this way ? Cheers, Willy -------- patch 1 : diff -urN linux-2.4.22-rc2/net/ipv4/arp.c linux-2.4.22-rc2-arp/net/ipv4/arp.c
--- linux-2.4.22-rc2/net/ipv4/arp.c Fri Aug 1 23:06:29 2003
+++ linux-2.4.22-rc2-arp/net/ipv4/arp.c Thu Aug 21 00:20:19 2003@@ -320,13 +320,20 @@ u32 saddr; u8 *dst_ha = NULL; struct net_device *dev = neigh->dev; + struct in_device *in_dev = in_dev_get(dev); u32 target = *(u32*)neigh->primary_key; int probes = atomic_read(&neigh->probes); - if (skb && inet_addr_type(skb->nh.iph->saddr) == RTN_LOCAL) + if (in_dev == NULL || in_dev->ifa_list == NULL || + (skb && inet_addr_type(skb->nh.iph->saddr) == RTN_LOCAL && + (IN_DEV_SHARED_MEDIA(in_dev) || + inet_addr_onlink(in_dev, skb->nh.iph->saddr, 0)))) saddr = skb->nh.iph->saddr; else saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); + + if (in_dev == NULL) + in_dev_put(in_dev); if ((probes -= neigh->parms->ucast_probes) < 0) { if (!(neigh->nud_state&NUD_VALID)) ---------
patch 2 : diff -urN linux-2.4.22-rc2/net/ipv4/arp.c linux-2.4.22-rc2-arp2/net/ipv4/arp.c
--- linux-2.4.22-rc2/net/ipv4/arp.c Fri Aug 1 23:06:29 2003
+++ linux-2.4.22-rc2-arp2/net/ipv4/arp.c Thu Aug 21 00:24:25 2003@@ -320,13 +320,19 @@ u32 saddr; u8 *dst_ha = NULL; struct net_device *dev = neigh->dev; + struct in_device *in_dev = in_dev_get(dev); u32 target = *(u32*)neigh->primary_key; int probes = atomic_read(&neigh->probes); - if (skb && inet_addr_type(skb->nh.iph->saddr) == RTN_LOCAL) - saddr = skb->nh.iph->saddr; + if (skb && inet_addr_type(skb->nh.iph->saddr) == RTN_LOCAL && + (in_dev == NULL || IN_DEV_SHARED_MEDIA(in_dev) || + (saddr = inet_select_addr(dev, target, RT_SCOPE_LINK)) == 0)) + saddr = skb->nh.iph->saddr; else saddr = inet_select_addr(dev, target, RT_SCOPE_LINK); + + if (in_dev == NULL) + in_dev_put(in_dev); if ((probes -= neigh->parms->ucast_probes) < 0) { if (!(neigh->nud_state&NUD_VALID))