RDMA/ucma: Allow user space to specify AF_IB when joining multicast

Allow user space applications to join multicast groups using MGIDs
directly.  MGIDs may be passed using AF_IB addresses.  Since the
current multicast join command only supports addresses as large as
sockaddr_in6, define a new structure for joining addresses specified
using sockaddr_ib.

Since AF_IB allows the user to specify the qkey when resolving a
remote UD QP address, when joining the multicast group use the qkey
value, if one has been assigned.

Signed-off-by: Sean Hefty <[email protected]>
Signed-off-by: Roland Dreier <[email protected]>

Author: shefty

drivers/infiniband/core/cma.c

@@ -3149,6 +3149,8 @@ static void cma_set_mgid(struct rdma_id_private *id_priv,
 								 0xFF10A01B)) {
 		/* IPv6 address is an SA assigned MGID. */
 		memcpy(mgid, &sin6->sin6_addr, sizeof *mgid);
+	} else if (addr->sa_family == AF_IB) {
+		memcpy(mgid, &((struct sockaddr_ib *) addr)->sib_addr, sizeof *mgid);
 	} else if ((addr->sa_family == AF_INET6)) {
 		ipv6_ib_mc_map(&sin6->sin6_addr, dev_addr->broadcast, mc_map);
 		if (id_priv->id.ps == RDMA_PS_UDP)
@@ -3176,9 +3178,12 @@ static int cma_join_ib_multicast(struct rdma_id_private *id_priv,
 	if (ret)
 		return ret;
 
+	ret = cma_set_qkey(id_priv, 0);
+	if (ret)
+		return ret;
+
 	cma_set_mgid(id_priv, (struct sockaddr *) &mc->addr, &rec.mgid);
-	if (id_priv->id.ps == RDMA_PS_UDP)
-		rec.qkey = cpu_to_be32(RDMA_UDP_QKEY);
+	rec.qkey = cpu_to_be32(id_priv->qkey);
 	rdma_addr_get_sgid(dev_addr, &rec.port_gid);
 	rec.pkey = cpu_to_be16(ib_addr_get_pkey(dev_addr));
 	rec.join_state = 1;

drivers/infiniband/core/ucma.c

@@ -1229,23 +1229,23 @@ static ssize_t ucma_notify(struct ucma_file *file, const char __user *inbuf,
 	return ret;
 }
 
-static ssize_t ucma_join_ip_multicast(struct ucma_file *file,
-				      const char __user *inbuf,
-				      int in_len, int out_len)
+static ssize_t ucma_process_join(struct ucma_file *file,
+				 struct rdma_ucm_join_mcast *cmd,  int out_len)
 {
-	struct rdma_ucm_join_ip_mcast cmd;
 	struct rdma_ucm_create_id_resp resp;
 	struct ucma_context *ctx;
 	struct ucma_multicast *mc;
+	struct sockaddr *addr;
 	int ret;
 
 	if (out_len < sizeof(resp))
 		return -ENOSPC;
 
-	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
-		return -EFAULT;
+	addr = (struct sockaddr *) &cmd->addr;
+	if (cmd->reserved || !cmd->addr_size || (cmd->addr_size != rdma_addr_size(addr)))
+		return -EINVAL;
 
-	ctx = ucma_get_ctx(file, cmd.id);
+	ctx = ucma_get_ctx(file, cmd->id);
 	if (IS_ERR(ctx))
 		return PTR_ERR(ctx);
 
@@ -1256,14 +1256,14 @@ static ssize_t ucma_join_ip_multicast(struct ucma_file *file,
 		goto err1;
 	}
 
-	mc->uid = cmd.uid;
-	memcpy(&mc->addr, &cmd.addr, sizeof cmd.addr);
+	mc->uid = cmd->uid;
+	memcpy(&mc->addr, addr, cmd->addr_size);
 	ret = rdma_join_multicast(ctx->cm_id, (struct sockaddr *) &mc->addr, mc);
 	if (ret)
 		goto err2;
 
 	resp.id = mc->id;
-	if (copy_to_user((void __user *)(unsigned long)cmd.response,
+	if (copy_to_user((void __user *)(unsigned long) cmd->response,
 			 &resp, sizeof(resp))) {
 		ret = -EFAULT;
 		goto err3;
@@ -1288,6 +1288,38 @@ static ssize_t ucma_join_ip_multicast(struct ucma_file *file,
 	return ret;
 }
 
+static ssize_t ucma_join_ip_multicast(struct ucma_file *file,
+				      const char __user *inbuf,
+				      int in_len, int out_len)
+{
+	struct rdma_ucm_join_ip_mcast cmd;
+	struct rdma_ucm_join_mcast join_cmd;
+
+	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
+		return -EFAULT;
+
+	join_cmd.response = cmd.response;
+	join_cmd.uid = cmd.uid;
+	join_cmd.id = cmd.id;
+	join_cmd.addr_size = rdma_addr_size((struct sockaddr *) &cmd.addr);
+	join_cmd.reserved = 0;
+	memcpy(&join_cmd.addr, &cmd.addr, join_cmd.addr_size);
+
+	return ucma_process_join(file, &join_cmd, out_len);
+}
+
+static ssize_t ucma_join_multicast(struct ucma_file *file,
+				   const char __user *inbuf,
+				   int in_len, int out_len)
+{
+	struct rdma_ucm_join_mcast cmd;
+
+	if (copy_from_user(&cmd, inbuf, sizeof(cmd)))
+		return -EFAULT;
+
+	return ucma_process_join(file, &cmd, out_len);
+}
+
 static ssize_t ucma_leave_multicast(struct ucma_file *file,
 				    const char __user *inbuf,
 				    int in_len, int out_len)
@@ -1451,7 +1483,8 @@ static ssize_t (*ucma_cmd_table[])(struct ucma_file *file,
 	[RDMA_USER_CM_CMD_MIGRATE_ID]	 = ucma_migrate_id,
 	[RDMA_USER_CM_CMD_QUERY]	 = ucma_query,
 	[RDMA_USER_CM_CMD_BIND]		 = ucma_bind,
-	[RDMA_USER_CM_CMD_RESOLVE_ADDR]	 = ucma_resolve_addr
+	[RDMA_USER_CM_CMD_RESOLVE_ADDR]	 = ucma_resolve_addr,
+	[RDMA_USER_CM_CMD_JOIN_MCAST]	 = ucma_join_multicast
 };
 
 static ssize_t ucma_write(struct file *filp, const char __user *buf,

include/uapi/rdma/rdma_user_cm.h

@@ -64,7 +64,8 @@ enum {
 	RDMA_USER_CM_CMD_MIGRATE_ID,
 	RDMA_USER_CM_CMD_QUERY,
 	RDMA_USER_CM_CMD_BIND,
-	RDMA_USER_CM_CMD_RESOLVE_ADDR
+	RDMA_USER_CM_CMD_RESOLVE_ADDR,
+	RDMA_USER_CM_CMD_JOIN_MCAST
 };
 
 /*
@@ -242,6 +243,15 @@ struct rdma_ucm_join_ip_mcast {
 	__u32 id;
 };
 
+struct rdma_ucm_join_mcast {
+	__u64 response;		/* rdma_ucma_create_id_resp */
+	__u64 uid;
+	__u32 id;
+	__u16 addr_size;
+	__u16 reserved;
+	struct sockaddr_storage addr;
+};
+
 struct rdma_ucm_get_event {
 	__u64 response;
 };