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IPoIB: improve IPv4/IPv6 to IB mcast mapping functions

RFC PATCH In review Roland Dreier 3 participants 3 messages Jan 4, 2008 – Jan 11, 2008 2 messages not in the archive

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A message that is not in the archive (sent off-list or not yet received): [email protected]

A message that is not in the archive (sent off-list or not yet received): [email protected]

Roland Dreier

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#2 lore raw

RFC PATCH 1/1 IPoIB: improve IPv4/IPv6 to IB mcast mapping functions

Any objection to merging the following for 2.6.25?

[Rolf -- I think it makes more sense to delete the overwriting of the P_Key in ipoib_multicast.c in this patch rather than later in the series; do you agree?]

Thanks,
Roland

From: Rolf Manderscheid <[email protected]>

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 <[email protected]>
Signed-off-by Roland Dreier <[email protected]>
---
 drivers/infiniband/core/cma.c                  |    4 +---
 drivers/infiniband/ulp/ipoib/ipoib_multicast.c |    4 ----
 include/net/if_inet6.h                         |   11 +++++++----
 include/net/ip.h                               |   10 ++++++----
 net/ipv4/arp.c                                 |    2 +-
 net/ipv6/ndisc.c                               |    2 +-
 6 files changed, 16 insertions(+), 17 deletions(-)
drivers/infiniband/core/cma.c +1 -3
index 312ec74..982836e 100644
@@ -2610,11 +2610,9 @@ static void cma_set_mgid(struct rdma_id_private *id_priv,
 		/* IPv6 address is an SA assigned MGID. */
 		memcpy(mgid, &sin6->sin6_addr, sizeof *mgid);
 	} else {
-		ip_ib_mc_map(sin->sin_addr.s_addr, mc_map);
+		ip_ib_mc_map(sin->sin_addr.s_addr, dev_addr->broadcast, mc_map);
 		if (id_priv->id.ps == RDMA_PS_UDP)
 			mc_map[7] = 0x01;	/* Use RDMA CM signature */
-		mc_map[8] = ib_addr_get_pkey(dev_addr) >> 8;
-		mc_map[9] = (unsigned char) ib_addr_get_pkey(dev_addr);
 		*mgid = *(union ib_gid *) (mc_map + 4);
 	}
 }
drivers/infiniband/ulp/ipoib/ipoib_multicast.c +0 -4
index 858ada1..2628339 100644
@@ -788,10 +788,6 @@ void ipoib_mcast_restart_task(struct work_struct *work)
 
 		memcpy(mgid.raw, mclist->dmi_addr + 4, sizeof mgid);
 
-		/* Add in the P_Key */
-		mgid.raw[4] = (priv->pkey >> 8) & 0xff;
-		mgid.raw[5] = priv->pkey & 0xff;
-
 		mcast = __ipoib_mcast_find(dev, &mgid);
 		if (!mcast || test_bit(IPOIB_MCAST_FLAG_SENDONLY, &mcast->flags)) {
 			struct ipoib_mcast *nmcast;
include/net/if_inet6.h +7 -4
index 448eccb..b24508a 100644
@@ -269,18 +269,21 @@ static inline void ipv6_arcnet_mc_map(const struct in6_addr *addr, char *buf)
 	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
include/net/ip.h +6 -4
index 840dd91..50c8889 100644
@@ -266,20 +266,22 @@ static inline void ip_eth_mc_map(__be32 naddr, char *buf)
  *	Leave P_Key as 0 to be filled in by driver.
  */
 
-static inline void ip_ib_mc_map(__be32 naddr, char *buf)
+static inline void ip_ib_mc_map(__be32 naddr, const unsigned char *broadcast, char *buf)
 {
 	__u32 addr;
+	unsigned char scope = broadcast[5] & 0xF;
+
 	buf[0]  = 0;		/* Reserved */
 	buf[1]  = 0xff;		/* Multicast QPN */
 	buf[2]  = 0xff;
 	buf[3]  = 0xff;
 	addr    = ntohl(naddr);
 	buf[4]  = 0xff;
-	buf[5]  = 0x12;		/* link local scope */
+	buf[5]  = 0x10 | scope;	/* scope from broadcast address */
 	buf[6]  = 0x40;		/* IPv4 signature */
 	buf[7]  = 0x1b;
-	buf[8]  = 0;		/* P_Key */
-	buf[9]  = 0;
+	buf[8]  = broadcast[8];		/* P_Key */
+	buf[9]  = broadcast[9];
 	buf[10] = 0;
 	buf[11] = 0;
 	buf[12] = 0;
net/ipv4/arp.c +1 -1
index 08174a2..54a76b8 100644
@@ -211,7 +211,7 @@ int arp_mc_map(__be32 addr, u8 *haddr, struct net_device *dev, int dir)
 		ip_tr_mc_map(addr, haddr);
 		return 0;
 	case ARPHRD_INFINIBAND:
-		ip_ib_mc_map(addr, haddr);
+		ip_ib_mc_map(addr, dev->broadcast, haddr);
 		return 0;
 	default:
 		if (dir) {
net/ipv6/ndisc.c +1 -1
index 777ed73..85947ea 100644
@@ -337,7 +337,7 @@ int ndisc_mc_map(struct in6_addr *addr, char *buf, struct net_device *dev, int d
 		ipv6_arcnet_mc_map(addr, buf);
 		return 0;
 	case ARPHRD_INFINIBAND:
-		ipv6_ib_mc_map(addr, buf);
+		ipv6_ib_mc_map(addr, dev->broadcast, buf);
 		return 0;
 	default:
 		if (dir) {
Signature · 1 line
1.5.4.rc2
#3 lore raw
Quoted 6 lines · Roland Dreier

Any objection to merging the following for 2.6.25?

[Rolf -- I think it makes more sense to delete the overwriting of the P_Key in ipoib_multicast.c in this patch rather than later in the series; do you agree?]

Yes, the first patch is the logical place for it. The only reason I put it in the second patch was to keep the first patch as small and simple as possible.

Rolf