Attachment 195377 Details for Bug 229957 – proposed fix for if_epair.c

[patch] proposed fix for if_epair.c

epair.diff (text/plain), 1.30 KB, created by Eugene Grosbein on 2018-07-22 18:06:25 UTC

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Creator: Eugene Grosbein

Created: 2018-07-22 18:06:25 UTC

Size: 1.30 KB

patch

obsolete

>Index: sys/net/if_epair.c
>===================================================================
>--- sys/net/if_epair.c	(revision 336460)
>+++ sys/net/if_epair.c	(working copy)
>@@ -107,6 +107,7 @@ static int epair_clone_create(struct if_
> static int epair_clone_destroy(struct if_clone *, struct ifnet *);
> 
> static const char epairname[] = "epair";
>+static unsigned int next_index = 0;
> 
> /* Netisr related definitions and sysctl. */
> static struct netisr_handler epair_nh = {
>@@ -843,12 +844,21 @@ epair_clone_create(struct if_clone *ifc,
> 
> 	/*
> 	 * Calculate the etheraddr hashing the hostid and the
>-	 * interface index. The result would be hopefully unique
>+	 * interface index. The result would be hopefully unique.
>+	 * Note that epair(4) may be created then "a" part moved to another
>+	 * VNET freeing if_index so next epair obtains same if_index.
>+	 * Make sure we do not create same etheraddr again.
> 	 */
> 	getcredhostid(curthread->td_ucred, (unsigned long *)&hostid);
> 	if (hostid == 0) 
> 		arc4rand(&hostid, sizeof(hostid), 0);
>-	key[0] = (uint32_t)ifp->if_index;
>+
>+	if (ifp->if_index > next_index)
>+		next_index = ifp->if_index;
>+	else
>+		next_index++;
>+
>+	key[0] = (uint32_t)next_index;
> 	key[1] = (uint32_t)(hostid & 0xffffffff);
> 	key[2] = (uint32_t)((hostid >> 32) & 0xfffffffff);
> 	hash = jenkins_hash32(key, 3, 0);

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Attachments on bug 229957: 195377