Commit bad5b6e3 authored by Chuck Lever's avatar Chuck Lever Committed by Jason Gunthorpe
Browse files

RDMA/siw: Fabricate a GID on tun and loopback devices 

LOOPBACK and NONE (tunnel) devices have all-zero MAC addresses.
Currently, siw_device_create() falls back to copying the IB device's
name in those cases, because an all-zero MAC address breaks the RDMA
core address resolution mechanism.

However, at the point when siw_device_create() constructs a GID, the
ib_device::name field is uninitialized, leaving the MAC address to
remain in an all-zero state.

Fabricate a random artificial GID for such devices, and ensure this
artificial GID is returned for all device query operations.

Link: https://lore.kernel.org/r/168960673260.3007.12378736853793339110.stgit@manet.1015granger.net


Reported-by: default avatarTom Talpey <tom@talpey.com>
Fixes: a2d36b02 ("RDMA/siw: Enable siw on tunnel devices")
Reviewed-by: default avatarBernard Metzler <bmt@zurich.ibm.com>
Reviewed-by: default avatarTom Talpey <tom@talpey.com>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
parent 666f526b

drivers/infiniband/sw/siw/siw.h

+1 −0
Original line number Diff line number Diff line
@@ -74,6 +74,7 @@ struct siw_device { 


	u32 vendor_part_id;

	int numa_node;

	char raw_gid[ETH_ALEN];



	/* physical port state (only one port per device) */

	enum ib_port_state state;

drivers/infiniband/sw/siw/siw_main.c

+8 −14
Original line number Diff line number Diff line
@@ -75,8 +75,7 @@ static int siw_device_register(struct siw_device *sdev, const char *name) 
		return rv;

	}



	siw_dbg(base_dev, "HWaddr=%pM\n", sdev->netdev->dev_addr);



	siw_dbg(base_dev, "HWaddr=%pM\n", sdev->raw_gid);

	return 0;

}
@@ -313,24 +312,19 @@ static struct siw_device *siw_device_create(struct net_device *netdev) 
		return NULL;



	base_dev = &sdev->base_dev;



	sdev->netdev = netdev;



	if (netdev->type != ARPHRD_LOOPBACK && netdev->type != ARPHRD_NONE) {

		addrconf_addr_eui48((unsigned char *)&base_dev->node_guid,

				    netdev->dev_addr);

	if (netdev->addr_len) {

		memcpy(sdev->raw_gid, netdev->dev_addr,

		       min_t(unsigned int, netdev->addr_len, ETH_ALEN));

	} else {

		/*

		 * This device does not have a HW address,

		 * but connection mangagement lib expects gid != 0

		 * This device does not have a HW address, but

		 * connection mangagement requires a unique gid.

		 */

		size_t len = min_t(size_t, strlen(base_dev->name), 6);

		char addr[6] = { };



		memcpy(addr, base_dev->name, len);

		addrconf_addr_eui48((unsigned char *)&base_dev->node_guid,

				    addr);

		eth_random_addr(sdev->raw_gid);

	}

	addrconf_addr_eui48((u8 *)&base_dev->node_guid, sdev->raw_gid);



	base_dev->uverbs_cmd_mask |= BIT_ULL(IB_USER_VERBS_CMD_POST_SEND);

drivers/infiniband/sw/siw/siw_verbs.c

+2 −2
Original line number Diff line number Diff line
@@ -157,7 +157,7 @@ int siw_query_device(struct ib_device *base_dev, struct ib_device_attr *attr, 
	attr->vendor_part_id = sdev->vendor_part_id;



	addrconf_addr_eui48((u8 *)&attr->sys_image_guid,

			    sdev->netdev->dev_addr);

			    sdev->raw_gid);



	return 0;

}
@@ -218,7 +218,7 @@ int siw_query_gid(struct ib_device *base_dev, u32 port, int idx, 


	/* subnet_prefix == interface_id == 0; */

	memset(gid, 0, sizeof(*gid));

	memcpy(&gid->raw[0], sdev->netdev->dev_addr, 6);

	memcpy(gid->raw, sdev->raw_gid, ETH_ALEN);



	return 0;

}