Messages in this thread | | | Subject | Re: [PATCH] RDMA/cma: fix IPv6 address resolution | From | Doug Ledford <> | Date | Thu, 3 Sep 2015 16:03:39 -0400 |
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On 08/13/2015 03:19 PM, Spencer Baugh wrote: > Resolving a link-local IPv6 address with an unspecified source address > was broken by commit 5462eddd7a, which prevented the IPv6 stack from > learning the scope id of the link-local IPv6 address, causing random > failures as the IP stack chose a random link to resolve the address on. > > This commit 5462eddd7a made us bail out of cma_check_linklocal early if > the address passed in was not an IPv6 link-local address. On the address > resolution path, the address passed in is the source address; if the > source address is the unspecified address, which is not link-local, we > will bail out early. > > This is mostly correct, but if the destination address is a link-local > address, then we will be following a link-local route, and we'll need to > tell the IPv6 stack what the scope id of the destination address is. > This used to be done by last line of cma_check_linklocal, which is > skipped when bailing out early: > > dev_addr->bound_dev_if = sin6->sin6_scope_id; > > (In cma_bind_addr, the sin6_scope_id of the source address is set to the > sin6_scope_id of the destination address, so this is correct) > This line is required in turn for the following line, L279 of > addr6_resolve, to actually inform the IPv6 stack of the scope id: > > fl6.flowi6_oif = addr->bound_dev_if; > > Since we can only know we are in this failure case when we have access > to both the source IPv6 address and destination IPv6 address, we have to > deal with this further up the stack. So detect this failure case in > cma_bind_addr, and set bound_dev_if to the destination address scope id > to correct it. > > Signed-off-by: Spencer Baugh <sbaugh@catern.com> > --- > drivers/infiniband/core/cma.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c > index 6a6b60a..3b71154 100644 > --- a/drivers/infiniband/core/cma.c > +++ b/drivers/infiniband/core/cma.c > @@ -2188,8 +2188,11 @@ static int cma_bind_addr(struct rdma_cm_id *id, struct sockaddr *src_addr, > src_addr = (struct sockaddr *) &id->route.addr.src_addr; > src_addr->sa_family = dst_addr->sa_family; > if (dst_addr->sa_family == AF_INET6) { > - ((struct sockaddr_in6 *) src_addr)->sin6_scope_id = > - ((struct sockaddr_in6 *) dst_addr)->sin6_scope_id; > + struct sockaddr_in6 *src_addr6 = (struct sockaddr_in6 *) src_addr; > + struct sockaddr_in6 *dst_addr6 = (struct sockaddr_in6 *) dst_addr; > + src_addr6->sin6_scope_id = dst_addr6->sin6_scope_id; > + if (ipv6_addr_type(&dst_addr6->sin6_addr) & IPV6_ADDR_LINKLOCAL) > + id->route.addr.dev_addr.bound_dev_if = dst_addr6->sin6_scope_id; > } else if (dst_addr->sa_family == AF_IB) { > ((struct sockaddr_ib *) src_addr)->sib_pkey = > ((struct sockaddr_ib *) dst_addr)->sib_pkey; >
Thanks, applied.
-- Doug Ledford <dledford@redhat.com> GPG KeyID: 0E572FDD
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