RDMA/cma: Add support for RDMA_PS_UDP

Allow the use of UD QPs through the rdma_cm, in order to provide
address translation services for resolving IB addresses for datagram
messages using SIDR.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

3 files changed, 222 insertions, 16 deletions

diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 9b036706f4d1..533193d4e5df 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -70,6 +70,7 @@ static DEFINE_MUTEX(lock);
 static struct workqueue_struct *cma_wq;
 static DEFINE_IDR(sdp_ps);
 static DEFINE_IDR(tcp_ps);
+static DEFINE_IDR(udp_ps);
 
 struct cma_device {
         struct list_head        list;
@@ -508,9 +509,17 @@ static inline int cma_any_addr(struct sockaddr *addr)
         return cma_zero_addr(addr) || cma_loopback_addr(addr);
 }
 
+static inline __be16 cma_port(struct sockaddr *addr)
+{
+        if (addr->sa_family == AF_INET)
+                return ((struct sockaddr_in *) addr)->sin_port;
+        else
+                return ((struct sockaddr_in6 *) addr)->sin6_port;
+}
+
 static inline int cma_any_port(struct sockaddr *addr)
 {
-        return !((struct sockaddr_in *) addr)->sin_port;
+        return !cma_port(addr);
 }
 
 static int cma_get_net_info(void *hdr, enum rdma_port_space ps,
@@ -847,8 +856,8 @@ out:
         return ret;
 }
 
-static struct rdma_id_private *cma_new_id(struct rdma_cm_id *listen_id,
-                                          struct ib_cm_event *ib_event)
+static struct rdma_id_private *cma_new_conn_id(struct rdma_cm_id *listen_id,
+                                               struct ib_cm_event *ib_event)
 {
         struct rdma_id_private *id_priv;
         struct rdma_cm_id *id;
@@ -895,6 +904,42 @@ err:
         return NULL;
 }
 
+static struct rdma_id_private *cma_new_udp_id(struct rdma_cm_id *listen_id,
+                                              struct ib_cm_event *ib_event)
+{
+        struct rdma_id_private *id_priv;
+        struct rdma_cm_id *id;
+        union cma_ip_addr *src, *dst;
+        __u16 port;
+        u8 ip_ver;
+        int ret;
+
+        id = rdma_create_id(listen_id->event_handler, listen_id->context,
+                            listen_id->ps);
+        if (IS_ERR(id))
+                return NULL;
+
+
+        if (cma_get_net_info(ib_event->private_data, listen_id->ps,
+                             &ip_ver, &port, &src, &dst))
+                goto err;
+
+        cma_save_net_info(&id->route.addr, &listen_id->route.addr,
+                          ip_ver, port, src, dst);
+
+        ret = rdma_translate_ip(&id->route.addr.src_addr,
+                                &id->route.addr.dev_addr);
+        if (ret)
+                goto err;
+
+        id_priv = container_of(id, struct rdma_id_private, id);
+        id_priv->state = CMA_CONNECT;
+        return id_priv;
+err:
+        rdma_destroy_id(id);
+        return NULL;
+}
+
 static void cma_set_req_event_data(struct rdma_cm_event *event,
                                    struct ib_cm_req_event_param *req_data,
                                    void *private_data, int offset)
@@ -923,7 +968,19 @@ static int cma_req_handler(struct ib_cm_id *cm_id, struct ib_cm_event *ib_event)
                 goto out;
         }
 
-        conn_id = cma_new_id(&listen_id->id, ib_event);
+        memset(&event, 0, sizeof event);
+        offset = cma_user_data_offset(listen_id->id.ps);
+        event.event = RDMA_CM_EVENT_CONNECT_REQUEST;
+        if (listen_id->id.ps == RDMA_PS_UDP) {
+                conn_id = cma_new_udp_id(&listen_id->id, ib_event);
+                event.param.ud.private_data = ib_event->private_data + offset;
+                event.param.ud.private_data_len =
+                                IB_CM_SIDR_REQ_PRIVATE_DATA_SIZE - offset;
+        } else {
+                conn_id = cma_new_conn_id(&listen_id->id, ib_event);
+                cma_set_req_event_data(&event, &ib_event->param.req_rcvd,
+                                       ib_event->private_data, offset);
+        }
         if (!conn_id) {
                 ret = -ENOMEM;
                 goto out;
@@ -940,11 +997,6 @@ static int cma_req_handler(struct ib_cm_id *cm_id, struct ib_cm_event *ib_event)
         cm_id->context = conn_id;
         cm_id->cm_handler = cma_ib_handler;
 
-        offset = cma_user_data_offset(listen_id->id.ps);
-        memset(&event, 0, sizeof event);
-        event.event = RDMA_CM_EVENT_CONNECT_REQUEST;
-        cma_set_req_event_data(&event, &ib_event->param.req_rcvd,
-                               ib_event->private_data, offset);
         ret = conn_id->id.event_handler(&conn_id->id, &event);
         if (!ret)
                 goto out;
@@ -964,8 +1016,7 @@ out:
 
 static __be64 cma_get_service_id(enum rdma_port_space ps, struct sockaddr *addr)
 {
-        return cpu_to_be64(((u64)ps << 16) +
-               be16_to_cpu(((struct sockaddr_in *) addr)->sin_port));
+        return cpu_to_be64(((u64)ps << 16) + be16_to_cpu(cma_port(addr)));
 }
 
 static void cma_set_compare_data(enum rdma_port_space ps, struct sockaddr *addr,
@@ -1740,6 +1791,9 @@ static int cma_get_port(struct rdma_id_private *id_priv)
         case RDMA_PS_TCP:
                 ps = &tcp_ps;
                 break;
+        case RDMA_PS_UDP:
+                ps = &udp_ps;
+                break;
         default:
                 return -EPROTONOSUPPORT;
         }
@@ -1828,6 +1882,110 @@ static int cma_format_hdr(void *hdr, enum rdma_port_space ps,
         return 0;
 }
 
+static int cma_sidr_rep_handler(struct ib_cm_id *cm_id,
+                                struct ib_cm_event *ib_event)
+{
+        struct rdma_id_private *id_priv = cm_id->context;
+        struct rdma_cm_event event;
+        struct ib_cm_sidr_rep_event_param *rep = &ib_event->param.sidr_rep_rcvd;
+        int ret = 0;
+
+        memset(&event, 0, sizeof event);
+        atomic_inc(&id_priv->dev_remove);
+        if (!cma_comp(id_priv, CMA_CONNECT))
+                goto out;
+
+        switch (ib_event->event) {
+        case IB_CM_SIDR_REQ_ERROR:
+                event.event = RDMA_CM_EVENT_UNREACHABLE;
+                event.status = -ETIMEDOUT;
+                break;
+        case IB_CM_SIDR_REP_RECEIVED:
+                event.param.ud.private_data = ib_event->private_data;
+                event.param.ud.private_data_len = IB_CM_SIDR_REP_PRIVATE_DATA_SIZE;
+                if (rep->status != IB_SIDR_SUCCESS) {
+                        event.event = RDMA_CM_EVENT_UNREACHABLE;
+                        event.status = ib_event->param.sidr_rep_rcvd.status;
+                        break;
+                }
+                if (rep->qkey != RDMA_UD_QKEY) {
+                        event.event = RDMA_CM_EVENT_UNREACHABLE;
+                        event.status = -EINVAL;
+                        break;
+                }
+                ib_init_ah_from_path(id_priv->id.device, id_priv->id.port_num,
+                                     id_priv->id.route.path_rec,
+                                     &event.param.ud.ah_attr);
+                event.param.ud.qp_num = rep->qpn;
+                event.param.ud.qkey = rep->qkey;
+                event.event = RDMA_CM_EVENT_ESTABLISHED;
+                event.status = 0;
+                break;
+        default:
+                printk(KERN_ERR "RDMA CMA: unexpected IB CM event: %d",
+                       ib_event->event);
+                goto out;
+        }
+
+        ret = id_priv->id.event_handler(&id_priv->id, &event);
+        if (ret) {
+                /* Destroy the CM ID by returning a non-zero value. */
+                id_priv->cm_id.ib = NULL;
+                cma_exch(id_priv, CMA_DESTROYING);
+                cma_release_remove(id_priv);
+                rdma_destroy_id(&id_priv->id);
+                return ret;
+        }
+out:
+        cma_release_remove(id_priv);
+        return ret;
+}
+
+static int cma_resolve_ib_udp(struct rdma_id_private *id_priv,
+                              struct rdma_conn_param *conn_param)
+{
+        struct ib_cm_sidr_req_param req;
+        struct rdma_route *route;
+        int ret;
+
+        req.private_data_len = sizeof(struct cma_hdr) +
+                               conn_param->private_data_len;
+        req.private_data = kzalloc(req.private_data_len, GFP_ATOMIC);
+        if (!req.private_data)
+                return -ENOMEM;
+
+        if (conn_param->private_data && conn_param->private_data_len)
+                memcpy((void *) req.private_data + sizeof(struct cma_hdr),
+                       conn_param->private_data, conn_param->private_data_len);
+
+        route = &id_priv->id.route;
+        ret = cma_format_hdr((void *) req.private_data, id_priv->id.ps, route);
+        if (ret)
+                goto out;
+
+        id_priv->cm_id.ib = ib_create_cm_id(id_priv->id.device,
+                                            cma_sidr_rep_handler, id_priv);
+        if (IS_ERR(id_priv->cm_id.ib)) {
+                ret = PTR_ERR(id_priv->cm_id.ib);
+                goto out;
+        }
+
+        req.path = route->path_rec;
+        req.service_id = cma_get_service_id(id_priv->id.ps,
+                                            &route->addr.dst_addr);
+        req.timeout_ms = 1 << (CMA_CM_RESPONSE_TIMEOUT - 8);
+        req.max_cm_retries = CMA_MAX_CM_RETRIES;
+
+        ret = ib_send_cm_sidr_req(id_priv->cm_id.ib, &req);
+        if (ret) {
+                ib_destroy_cm_id(id_priv->cm_id.ib);
+                id_priv->cm_id.ib = NULL;
+        }
+out:
+        kfree(req.private_data);
+        return ret;
+}
+
 static int cma_connect_ib(struct rdma_id_private *id_priv,
                           struct rdma_conn_param *conn_param)
 {
@@ -1949,7 +2107,10 @@ int rdma_connect(struct rdma_cm_id *id, struct rdma_conn_param *conn_param)
 
         switch (rdma_node_get_transport(id->device->node_type)) {
         case RDMA_TRANSPORT_IB:
-                ret = cma_connect_ib(id_priv, conn_param);
+                if (id->ps == RDMA_PS_UDP)
+                        ret = cma_resolve_ib_udp(id_priv, conn_param);
+                else
+                        ret = cma_connect_ib(id_priv, conn_param);
                 break;
         case RDMA_TRANSPORT_IWARP:
                 ret = cma_connect_iw(id_priv, conn_param);
@@ -2032,6 +2193,24 @@ static int cma_accept_iw(struct rdma_id_private *id_priv,
         return iw_cm_accept(id_priv->cm_id.iw, &iw_param);
 }
 
+static int cma_send_sidr_rep(struct rdma_id_private *id_priv,
+                             enum ib_cm_sidr_status status,
+                             const void *private_data, int private_data_len)
+{
+        struct ib_cm_sidr_rep_param rep;
+
+        memset(&rep, 0, sizeof rep);
+        rep.status = status;
+        if (status == IB_SIDR_SUCCESS) {
+                rep.qp_num = id_priv->qp_num;
+                rep.qkey = RDMA_UD_QKEY;
+        }
+        rep.private_data = private_data;
+        rep.private_data_len = private_data_len;
+
+        return ib_send_cm_sidr_rep(id_priv->cm_id.ib, &rep);
+}
+
 int rdma_accept(struct rdma_cm_id *id, struct rdma_conn_param *conn_param)
 {
         struct rdma_id_private *id_priv;
@@ -2048,7 +2227,11 @@ int rdma_accept(struct rdma_cm_id *id, struct rdma_conn_param *conn_param)
 
         switch (rdma_node_get_transport(id->device->node_type)) {
         case RDMA_TRANSPORT_IB:
-                if (conn_param)
+                if (id->ps == RDMA_PS_UDP)
+                        ret = cma_send_sidr_rep(id_priv, IB_SIDR_SUCCESS,
+                                                conn_param->private_data,
+                                                conn_param->private_data_len);
+                else if (conn_param)
                         ret = cma_accept_ib(id_priv, conn_param);
                 else
                         ret = cma_rep_recv(id_priv);
@@ -2105,9 +2288,13 @@ int rdma_reject(struct rdma_cm_id *id, const void *private_data,
 
         switch (rdma_node_get_transport(id->device->node_type)) {
         case RDMA_TRANSPORT_IB:
-                ret = ib_send_cm_rej(id_priv->cm_id.ib,
-                                     IB_CM_REJ_CONSUMER_DEFINED, NULL, 0,
-                                     private_data, private_data_len);
+                if (id->ps == RDMA_PS_UDP)
+                        ret = cma_send_sidr_rep(id_priv, IB_SIDR_REJECT,
+                                                private_data, private_data_len);
+                else
+                        ret = ib_send_cm_rej(id_priv->cm_id.ib,
+                                             IB_CM_REJ_CONSUMER_DEFINED, NULL,
+                                             0, private_data, private_data_len);
                 break;
         case RDMA_TRANSPORT_IWARP:
                 ret = iw_cm_reject(id_priv->cm_id.iw,
@@ -2277,6 +2464,7 @@ static void cma_cleanup(void)
         destroy_workqueue(cma_wq);
         idr_destroy(&sdp_ps);
         idr_destroy(&tcp_ps);
+        idr_destroy(&udp_ps);
 }
 
 module_init(cma_init);
diff --git a/include/rdma/rdma_cm.h b/include/rdma/rdma_cm.h
index 6b8ec486d06b..36cd8a8526a0 100644
--- a/include/rdma/rdma_cm.h
+++ b/include/rdma/rdma_cm.h
@@ -90,11 +90,20 @@ struct rdma_conn_param {
         u32 qp_num;
 };
 
+struct rdma_ud_param {
+        const void *private_data;
+        u8 private_data_len;
+        struct ib_ah_attr ah_attr;
+        u32 qp_num;
+        u32 qkey;
+};
+
 struct rdma_cm_event {
         enum rdma_cm_event_type  event;
         int                      status;
         union {
                 struct rdma_conn_param  conn;
+                struct rdma_ud_param    ud;
         } param;
 };
 
@@ -220,9 +229,15 @@ int rdma_init_qp_attr(struct rdma_cm_id *id, struct ib_qp_attr *qp_attr,
 
 /**
  * rdma_connect - Initiate an active connection request.
+ * @id: Connection identifier to connect.
+ * @conn_param: Connection information used for connected QPs.
  *
  * Users must have resolved a route for the rdma_cm_id to connect with
  * by having called rdma_resolve_route before calling this routine.
+ *
+ * This call will either connect to a remote QP or obtain remote QP
+ * information for unconnected rdma_cm_id's.  The actual operation is
+ * based on the rdma_cm_id's port space.
  */
 int rdma_connect(struct rdma_cm_id *id, struct rdma_conn_param *conn_param);
 
diff --git a/include/rdma/rdma_cm_ib.h b/include/rdma/rdma_cm_ib.h
index e8c3af1804d4..9b176df1d667 100644
--- a/include/rdma/rdma_cm_ib.h
+++ b/include/rdma/rdma_cm_ib.h
@@ -44,4 +44,7 @@
 int rdma_set_ib_paths(struct rdma_cm_id *id,
                       struct ib_sa_path_rec *path_rec, int num_paths);
 
+/* Global qkey for UD QPs and multicast groups. */
+#define RDMA_UD_QKEY 0x01234567
+
 #endif /* RDMA_CM_IB_H */