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 <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 44 insertions, 11 deletions

diff --git a/drivers/infiniband/core/ucma.c b/drivers/infiniband/core/ucma.c
index 00ce99044a48..b0f189be543b 100644
--- a/drivers/infiniband/core/ucma.c
+++ b/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 @@ err1:
 	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,