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>

3 files changed, 62 insertions, 14 deletions

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 32d74c76e638..3d30c388e043 100644
--- a/drivers/infiniband/core/cma.c
+++ b/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;
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,
diff --git a/include/uapi/rdma/rdma_user_cm.h b/include/uapi/rdma/rdma_user_cm.h
index 6d03f9c16f1e..99b80abf360a 100644
--- a/include/uapi/rdma/rdma_user_cm.h
+++ b/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;
 };