RDMA/IWPM: Support no port mapping requirements

A soft iwarp driver that uses the host TCP stack via a kernel mode socket
does not need port mapping.  In fact, if the port map daemon, iwpmd, is
running, then iwpmd must not try and create/bind a socket to the actual
port for a soft iwarp connection, since the driver already has that socket
bound.

Yet if the soft iwarp driver wants to interoperate with hard iwarp devices
that -are- using port mapping, then the soft iwarp driver's mappings still
need to be maintained and advertised by the iwpm protocol.

This patch enhances the rdma driver<->iwcm interface to allow an iwarp
driver to specify that it does not want port mapping.  The iwpm
kernel<->iwpmd interface is also enhanced to pass up this information on
map requests.

Care is taken to interoperate with the current iwpmd version (ABI version
3) and only use the new NL attributes if iwpmd supports ABI version 4.

The ABI version define has also been created in rdma_netlink.h so both
kernel and user code can share it.  The iwcm and iwpmd negotiate the ABI
version to use with a new HELLO netlink message.

Signed-off-by: Steve Wise <swise@opengridcomputing.com>
Reviewed-by: Tatyana Nikolova <Tatyana.E.Nikolova@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

1 files changed, 77 insertions, 3 deletions

diff --git a/drivers/infiniband/core/iwpm_msg.c b/drivers/infiniband/core/iwpm_msg.c
index 3a8753595c8f..2e30e65b0816 100644
--- a/drivers/infiniband/core/iwpm_msg.c
+++ b/drivers/infiniband/core/iwpm_msg.c
@@ -34,7 +34,7 @@
 #include "iwpm_util.h"
 
 static const char iwpm_ulib_name[IWPM_ULIBNAME_SIZE] = "iWarpPortMapperUser";
-static int iwpm_ulib_version = 3;
+u16 iwpm_ulib_version = IWPM_UABI_VERSION_MIN;
 static int iwpm_user_pid = IWPM_PID_UNDEFINED;
 static atomic_t echo_nlmsg_seq;
 
@@ -130,6 +130,7 @@ pid_query_error:
  * nlmsg attributes:
  *	[IWPM_NLA_MANAGE_MAPPING_SEQ]
  *	[IWPM_NLA_MANAGE_ADDR]
+ *	[IWPM_NLA_MANAGE_FLAGS]
  */
 int iwpm_add_mapping(struct iwpm_sa_data *pm_msg, u8 nl_client)
 {
@@ -173,6 +174,18 @@ int iwpm_add_mapping(struct iwpm_sa_data *pm_msg, u8 nl_client)
 	if (ret)
 		goto add_mapping_error;
 
+	/* If flags are required and we're not V4, then return a quiet error */
+	if (pm_msg->flags && iwpm_ulib_version == IWPM_UABI_VERSION_MIN) {
+		ret = -EINVAL;
+		goto add_mapping_error_nowarn;
+	}
+	if (iwpm_ulib_version > IWPM_UABI_VERSION_MIN) {
+		ret = ibnl_put_attr(skb, nlh, sizeof(u32), &pm_msg->flags,
+				IWPM_NLA_MANAGE_FLAGS);
+		if (ret)
+			goto add_mapping_error;
+	}
+
 	nlmsg_end(skb, nlh);
 	nlmsg_request->req_buffer = pm_msg;
 
@@ -187,6 +200,7 @@ int iwpm_add_mapping(struct iwpm_sa_data *pm_msg, u8 nl_client)
 	return ret;
 add_mapping_error:
 	pr_info("%s: %s (client = %d)\n", __func__, err_str, nl_client);
+add_mapping_error_nowarn:
 	if (skb)
 		dev_kfree_skb(skb);
 	if (nlmsg_request)
@@ -201,6 +215,7 @@ add_mapping_error:
  *	[IWPM_NLA_QUERY_MAPPING_SEQ]
  *	[IWPM_NLA_QUERY_LOCAL_ADDR]
  *	[IWPM_NLA_QUERY_REMOTE_ADDR]
+ *	[IWPM_NLA_QUERY_FLAGS]
  */
 int iwpm_add_and_query_mapping(struct iwpm_sa_data *pm_msg, u8 nl_client)
 {
@@ -251,6 +266,18 @@ int iwpm_add_and_query_mapping(struct iwpm_sa_data *pm_msg, u8 nl_client)
 	if (ret)
 		goto query_mapping_error;
 
+	/* If flags are required and we're not V4, then return a quite error */
+	if (pm_msg->flags && iwpm_ulib_version == IWPM_UABI_VERSION_MIN) {
+		ret = -EINVAL;
+		goto query_mapping_error_nowarn;
+	}
+	if (iwpm_ulib_version > IWPM_UABI_VERSION_MIN) {
+		ret = ibnl_put_attr(skb, nlh, sizeof(u32), &pm_msg->flags,
+				IWPM_NLA_QUERY_FLAGS);
+		if (ret)
+			goto query_mapping_error;
+	}
+
 	nlmsg_end(skb, nlh);
 	nlmsg_request->req_buffer = pm_msg;
 
@@ -264,6 +291,7 @@ int iwpm_add_and_query_mapping(struct iwpm_sa_data *pm_msg, u8 nl_client)
 	return ret;
 query_mapping_error:
 	pr_info("%s: %s (client = %d)\n", __func__, err_str, nl_client);
+query_mapping_error_nowarn:
 	if (skb)
 		dev_kfree_skb(skb);
 	if (nlmsg_request)
@@ -379,7 +407,7 @@ int iwpm_register_pid_cb(struct sk_buff *skb, struct netlink_callback *cb)
 	/* check device name, ulib name and version */
 	if (strcmp(pm_msg->dev_name, dev_name) ||
 			strcmp(iwpm_ulib_name, iwpm_name) ||
-			iwpm_version != iwpm_ulib_version) {
+			iwpm_version < IWPM_UABI_VERSION_MIN) {
 
 		pr_info("%s: Incorrect info (dev = %s name = %s version = %d)\n",
 				__func__, dev_name, iwpm_name, iwpm_version);
@@ -387,6 +415,10 @@ int iwpm_register_pid_cb(struct sk_buff *skb, struct netlink_callback *cb)
 		goto register_pid_response_exit;
 	}
 	iwpm_user_pid = cb->nlh->nlmsg_pid;
+	iwpm_ulib_version = iwpm_version;
+	if (iwpm_ulib_version < IWPM_UABI_VERSION)
+		pr_warn_once("%s: Down level iwpmd/pid %u.  Continuing...",
+			__func__, iwpm_user_pid);
 	atomic_set(&echo_nlmsg_seq, cb->nlh->nlmsg_seq);
 	pr_debug("%s: iWarp Port Mapper (pid = %d) is available!\n",
 			__func__, iwpm_user_pid);
@@ -661,7 +693,7 @@ int iwpm_mapping_info_cb(struct sk_buff *skb, struct netlink_callback *cb)
 	iwpm_name = (char *)nla_data(nltb[IWPM_NLA_MAPINFO_ULIB_NAME]);
 	iwpm_version = nla_get_u16(nltb[IWPM_NLA_MAPINFO_ULIB_VER]);
 	if (strcmp(iwpm_ulib_name, iwpm_name) ||
-			iwpm_version != iwpm_ulib_version) {
+			iwpm_version < IWPM_UABI_VERSION_MIN) {
 		pr_info("%s: Invalid port mapper name = %s version = %d\n",
 				__func__, iwpm_name, iwpm_version);
 		return ret;
@@ -675,6 +707,11 @@ int iwpm_mapping_info_cb(struct sk_buff *skb, struct netlink_callback *cb)
 	iwpm_set_registration(nl_client, IWPM_REG_INCOMPL);
 	atomic_set(&echo_nlmsg_seq, cb->nlh->nlmsg_seq);
 	iwpm_user_pid = cb->nlh->nlmsg_pid;
+
+	if (iwpm_ulib_version < IWPM_UABI_VERSION)
+		pr_warn_once("%s: Down level iwpmd/pid %u.  Continuing...",
+			__func__, iwpm_user_pid);
+
 	if (!iwpm_mapinfo_available())
 		return 0;
 	pr_debug("%s: iWarp Port Mapper (pid = %d) is available!\n",
@@ -754,3 +791,40 @@ int iwpm_mapping_error_cb(struct sk_buff *skb, struct netlink_callback *cb)
 	up(&nlmsg_request->sem);
 	return 0;
 }
+
+/* netlink attribute policy for the received hello request */
+static const struct nla_policy hello_policy[IWPM_NLA_HELLO_MAX] = {
+	[IWPM_NLA_HELLO_ABI_VERSION]     = { .type = NLA_U16 }
+};
+
+/*
+ * iwpm_hello_cb - Process a port mapper hello request
+ */
+int iwpm_hello_cb(struct sk_buff *skb, struct netlink_callback *cb)
+{
+	struct nlattr *nltb[IWPM_NLA_HELLO_MAX];
+	const char *msg_type = "Hello request";
+	u8 nl_client;
+	u16 abi_version;
+	int ret = -EINVAL;
+
+	if (iwpm_parse_nlmsg(cb, IWPM_NLA_HELLO_MAX, hello_policy, nltb,
+			     msg_type)) {
+		pr_info("%s: Unable to parse nlmsg\n", __func__);
+		return ret;
+	}
+	abi_version = nla_get_u16(nltb[IWPM_NLA_HELLO_ABI_VERSION]);
+	nl_client = RDMA_NL_GET_CLIENT(cb->nlh->nlmsg_type);
+	if (!iwpm_valid_client(nl_client)) {
+		pr_info("%s: Invalid port mapper client = %d\n",
+				__func__, nl_client);
+		return ret;
+	}
+	iwpm_set_registration(nl_client, IWPM_REG_INCOMPL);
+	atomic_set(&echo_nlmsg_seq, cb->nlh->nlmsg_seq);
+	iwpm_ulib_version = min_t(u16, IWPM_UABI_VERSION, abi_version);
+	pr_debug("Using ABI version %u\n", iwpm_ulib_version);
+	iwpm_user_pid = cb->nlh->nlmsg_pid;
+	ret = iwpm_send_hello(nl_client, iwpm_user_pid, iwpm_ulib_version);
+	return ret;
+}