IPoIB: improve IPv4/IPv6 to IB mcast mapping functions
An IPoIB subnet on an IB fabric that spans multiple IB subnets can't
use link-local scope in multicast GIDs. The existing routines that
map IP/IPv6 multicast addresses into IB link-level addresses hard-code
the scope to link-local, and they also leave the partition key field
uninitialised. This patch adds a parameter (the link-level broadcast
address) to the mapping routines, allowing them to initialise both the
scope and the P_Key appropriately, and fixes up the call sites.
The next step will be to add a way to configure the scope for an IPoIB
interface.
Signed-off-by: Rolf Manderscheid <rvm@obsidianresearch.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
index 448eccb..b24508a 100644
--- a/include/net/if_inet6.h
+++ b/include/net/if_inet6.h
@@ -269,18 +269,21 @@
buf[0] = 0x00;
}
-static inline void ipv6_ib_mc_map(struct in6_addr *addr, char *buf)
+static inline void ipv6_ib_mc_map(const struct in6_addr *addr,
+ const unsigned char *broadcast, char *buf)
{
+ unsigned char scope = broadcast[5] & 0xF;
+
buf[0] = 0; /* Reserved */
buf[1] = 0xff; /* Multicast QPN */
buf[2] = 0xff;
buf[3] = 0xff;
buf[4] = 0xff;
- buf[5] = 0x12; /* link local scope */
+ buf[5] = 0x10 | scope; /* scope from broadcast address */
buf[6] = 0x60; /* IPv6 signature */
buf[7] = 0x1b;
- buf[8] = 0; /* P_Key */
- buf[9] = 0;
+ buf[8] = broadcast[8]; /* P_Key */
+ buf[9] = broadcast[9];
memcpy(buf + 10, addr->s6_addr + 6, 10);
}
#endif
