Re: [PATCH V3 for-next 3/4] IB/core: Export ib_create/destroy_flow through uverbs

On 18/7/2013 2:31 AM, Hefty, Sean wrote:

quoted

+ssize_t ib_uverbs_create_flow(struct ib_uverbs_file *file,
+			      const char __user *buf, int in_len,
+			      int out_len)
+{
+	struct ib_uverbs_create_flow	  cmd;
+	struct ib_uverbs_create_flow_resp resp;
+	struct ib_uobject		  *uobj;
+	struct ib_flow			  *flow_id;
+	struct ib_kern_flow_attr	  *kern_flow_attr;
+	struct ib_flow_attr		  *flow_attr;
+	struct ib_qp			  *qp;
+	int err = 0;
+	void *kern_spec;
+	void *ib_spec;
+	int i;
+
+	if (out_len < sizeof(resp))
+		return -ENOSPC;
+
+	if (copy_from_user(&cmd, buf, sizeof(cmd)))
+		return -EFAULT;
+
+	if ((cmd.flow_attr.type == IB_FLOW_ATTR_SNIFFER &&
+	     !capable(CAP_NET_ADMIN)) || !capable(CAP_NET_RAW))
+		return -EPERM;
+
+	if (cmd.flow_attr.num_of_specs) {
+		kern_flow_attr = kmalloc(cmd.flow_attr.size, GFP_KERNEL);
+		if (!kern_flow_attr)
+			return -ENOMEM;
+
+		memcpy(kern_flow_attr, &cmd.flow_attr, sizeof(*kern_flow_attr));
+		if (copy_from_user(kern_flow_attr + 1, buf + sizeof(cmd),
+				   cmd.flow_attr.size - sizeof(cmd))) {
+			err = -EFAULT;
+			goto err_free_attr;
+		}
+	} else {
+		kern_flow_attr = &cmd.flow_attr;
+	}
+
+	uobj = kmalloc(sizeof(*uobj), GFP_KERNEL);
+	if (!uobj) {
+		err = -ENOMEM;
+		goto err_free_attr;
+	}
+	init_uobj(uobj, 0, file->ucontext, &rule_lock_class);
+	down_write(&uobj->mutex);
+
+	qp = idr_read_qp(cmd.qp_handle, file->ucontext);
+	if (!qp) {
+		err = -EINVAL;
+		goto err_uobj;
+	}
+
+	flow_attr = kmalloc(cmd.flow_attr.size, GFP_KERNEL);
+	if (!flow_attr) {
+		err = -ENOMEM;
+		goto err_put;
+	}
+
+	flow_attr->type = kern_flow_attr->type;
+	flow_attr->priority = kern_flow_attr->priority;
+	flow_attr->num_of_specs = kern_flow_attr->num_of_specs;
+	flow_attr->port = kern_flow_attr->port;
+	flow_attr->flags = kern_flow_attr->flags;
+	flow_attr->size = sizeof(*flow_attr);
+
+	kern_spec = kern_flow_attr + 1;
+	ib_spec = flow_attr + 1;
+	for (i = 0; i < flow_attr->num_of_specs; i++) {
+		err = kern_spec_to_ib_spec(kern_spec, ib_spec);
+		if (err)
+			goto err_free;
+		flow_attr->size +=
+			((struct _ib_flow_spec *)ib_spec)->size;
+		kern_spec += ((struct ib_kern_spec *)kern_spec)->size;
+		ib_spec += ((struct _ib_flow_spec *)ib_spec)->size;

I didn't see where the ib_kern_spec size field was validated.  Maybe add this check to kern_spec_to_ib_spec?

It wasn't validated. The function could be written in a more secured way. Meaning, we should only loop until we met flow_attr->num_of_specs or we exhausted all the bytes we copied from the user.
Furthermore, as you said, it'll be more secured to add a new check in kern_spec_to_ib_spec that verifies that the size that the user sent matches the size of the kernel's struct.

quoted

+	}
+	flow_id = ib_create_flow(qp, flow_attr, IB_FLOW_DOMAIN_USER);
+	if (IS_ERR(flow_id)) {
+		err = PTR_ERR(flow_id);
+		goto err_free;
+	}
+	flow_id->qp = qp;
+	flow_id->uobject = uobj;
+	uobj->object = flow_id;
+
+	err = idr_add_uobj(&ib_uverbs_rule_idr, uobj);
+	if (err)
+		goto destroy_flow;
+
+	memset(&resp, 0, sizeof(resp));
+	resp.flow_handle = uobj->id;
+
+	if (copy_to_user((void __user *)(unsigned long) cmd.response,
+			 &resp, sizeof(resp))) {
+		err = -EFAULT;
+		goto err_copy;
+	}
+
+	put_qp_read(qp);
+	mutex_lock(&file->mutex);
+	list_add_tail(&uobj->list, &file->ucontext->rule_list);
+	mutex_unlock(&file->mutex);
+
+	uobj->live = 1;
+
+	up_write(&uobj->mutex);
+	kfree(flow_attr);
+	if (cmd.flow_attr.num_of_specs)
+		kfree(kern_flow_attr);
+	return in_len;
+err_copy:
+	idr_remove_uobj(&ib_uverbs_rule_idr, uobj);
+destroy_flow:
+	ib_destroy_flow(flow_id);
+err_free:
+	kfree(flow_attr);
+err_put:
+	put_qp_read(qp);
+err_uobj:
+	put_uobj_write(uobj);
+err_free_attr:
+	if (cmd.flow_attr.num_of_specs)
+		kfree(kern_flow_attr);
+	return err;
+}
+
+ssize_t ib_uverbs_destroy_flow(struct ib_uverbs_file *file,
+			       const char __user *buf, int in_len,
+			       int out_len) {
+	struct ib_uverbs_destroy_flow	cmd;
+	struct ib_flow			*flow_id;
+	struct ib_uobject		*uobj;
+	int				ret;
+
+	if (copy_from_user(&cmd, buf, sizeof(cmd)))
+		return -EFAULT;
+
+	uobj = idr_write_uobj(&ib_uverbs_rule_idr, cmd.flow_handle,
+			      file->ucontext);
+	if (!uobj)
+		return -EINVAL;
+	flow_id = uobj->object;
+
+	ret = ib_destroy_flow(flow_id);
+	if (!ret)
+		uobj->live = 0;
+
+	put_uobj_write(uobj);
+
+	idr_remove_uobj(&ib_uverbs_rule_idr, uobj);
+
+	mutex_lock(&file->mutex);
+	list_del(&uobj->list);
+	mutex_unlock(&file->mutex);
+
+	put_uobj(uobj);
+
+	return ret ? ret : in_len;
+}
+
  static int __uverbs_create_xsrq(struct ib_uverbs_file *file,
  				struct ib_uverbs_create_xsrq *cmd,
  				struct ib_udata *udata)

diff --git a/drivers/infiniband/core/uverbs_main.c

b/drivers/infiniband/core/uverbs_main.c
index e4e7b24..75ad86c 100644

--- a/drivers/infiniband/core/uverbs_main.c
+++ b/drivers/infiniband/core/uverbs_main.c

@@ -73,6 +73,7 @@ DEFINE_IDR(ib_uverbs_cq_idr);
  DEFINE_IDR(ib_uverbs_qp_idr);
  DEFINE_IDR(ib_uverbs_srq_idr);
  DEFINE_IDR(ib_uverbs_xrcd_idr);
+DEFINE_IDR(ib_uverbs_rule_idr);

  static DEFINE_SPINLOCK(map_lock);
  static DECLARE_BITMAP(dev_map, IB_UVERBS_MAX_DEVICES);

@@ -113,7 +114,9 @@ static ssize_t (*uverbs_cmd_table[])(struct ib_uverbs_file

*file,
  	[IB_USER_VERBS_CMD_OPEN_XRCD]		= ib_uverbs_open_xrcd,
  	[IB_USER_VERBS_CMD_CLOSE_XRCD]		= ib_uverbs_close_xrcd,
  	[IB_USER_VERBS_CMD_CREATE_XSRQ]		= ib_uverbs_create_xsrq,
-	[IB_USER_VERBS_CMD_OPEN_QP]		= ib_uverbs_open_qp
+	[IB_USER_VERBS_CMD_OPEN_QP]		= ib_uverbs_open_qp,
+	[IB_USER_VERBS_CMD_CREATE_FLOW]		= ib_uverbs_create_flow,
+	[IB_USER_VERBS_CMD_DESTROY_FLOW]	= ib_uverbs_destroy_flow
  };

  static void ib_uverbs_add_one(struct ib_device *device);

@@ -212,6 +215,14 @@ static int ib_uverbs_cleanup_ucontext(struct

ib_uverbs_file *file,
  		kfree(uobj);
  	}

+	list_for_each_entry_safe(uobj, tmp, &context->rule_list, list) {
+		struct ib_flow *flow_id = uobj->object;
+
+		idr_remove_uobj(&ib_uverbs_rule_idr, uobj);
+		ib_destroy_flow(flow_id);
+		kfree(uobj);
+	}
+
  	list_for_each_entry_safe(uobj, tmp, &context->qp_list, list) {
  		struct ib_qp *qp = uobj->object;
  		struct ib_uqp_object *uqp =

diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
index 1390a0f..4fe1f1c 100644
--- a/include/rdma/ib_verbs.h
+++ b/include/rdma/ib_verbs.h

@@ -923,6 +923,7 @@ struct ib_ucontext {
  	struct list_head	srq_list;
  	struct list_head	ah_list;
  	struct list_head	xrcd_list;
+	struct list_head	rule_list;
  	int			closing;
  };

diff --git a/include/uapi/rdma/ib_user_verbs.h

b/include/uapi/rdma/ib_user_verbs.h
index 61535aa..8c67534 100644

--- a/include/uapi/rdma/ib_user_verbs.h
+++ b/include/uapi/rdma/ib_user_verbs.h

@@ -86,7 +86,9 @@ enum {
  	IB_USER_VERBS_CMD_OPEN_XRCD,
  	IB_USER_VERBS_CMD_CLOSE_XRCD,
  	IB_USER_VERBS_CMD_CREATE_XSRQ,
-	IB_USER_VERBS_CMD_OPEN_QP
+	IB_USER_VERBS_CMD_OPEN_QP,
+	IB_USER_VERBS_CMD_CREATE_FLOW = IB_USER_VERBS_CMD_THRESHOLD,
+	IB_USER_VERBS_CMD_DESTROY_FLOW
  };

  /*

@@ -694,6 +696,90 @@ struct ib_uverbs_detach_mcast {
  	__u64 driver_data[0];
  };

+struct ib_kern_eth_filter {
+	__u8  dst_mac[6];
+	__u8  src_mac[6];
+	__be16 ether_type;
+	__be16 vlan_tag;
+};
+
+struct ib_kern_spec_eth {
+	__u32  type;
+	__u16  size;
+	__u16  reserved;
+	struct ib_kern_eth_filter val;
+	struct ib_kern_eth_filter mask;
+};
+
+struct ib_kern_ipv4_filter {
+	__be32 src_ip;
+	__be32 dst_ip;
+};
+
+struct ib_kern_spec_ipv4 {
+	__u32  type;
+	__u16  size;
+	__u16  reserved;
+	struct ib_kern_ipv4_filter val;
+	struct ib_kern_ipv4_filter mask;
+};
+
+struct ib_kern_tcp_udp_filter {
+	__be16 dst_port;
+	__be16 src_port;
+};
+
+struct ib_kern_spec_tcp_udp {
+	__u32  type;
+	__u16  size;
+	__u16  reserved;
+	struct ib_kern_tcp_udp_filter val;
+	struct ib_kern_tcp_udp_filter mask;
+};
+
+struct ib_kern_spec {
+	union {
+		struct {
+			__u32 type;
+			__u16 size;
+		};
+		struct ib_kern_spec_eth	    eth;
+		struct ib_kern_spec_ipv4    ipv4;
+		struct ib_kern_spec_tcp_udp tcp_udp;
+	};
+};
+
+struct ib_kern_flow_attr {
+	__u32 type;
+	__u16 size;
+	__u16 priority;
+	__u8  num_of_specs;
+	__u8  reserved[2];
+	__u8  port;
+	__u32 flags;
+	/* Following are the optional layers according to user request
+	 * struct ib_flow_spec_xxx
+	 * struct ib_flow_spec_yyy
+	 */
+};
+
+struct ib_uverbs_create_flow  {
+	__u32 comp_mask;
+	__u64 response;
+	__u32 qp_handle;
+	struct ib_kern_flow_attr flow_attr;
+};
+
+struct ib_uverbs_create_flow_resp {
+	__u32 comp_mask;
+	__u32 flow_handle;
+};
+
+struct ib_uverbs_destroy_flow  {
+	__u32 comp_mask;
+	__u32 flow_handle;
+};

The ib_uvers structures contain a comp_mask field, but I didn't see that those were used.

comp_mask is a field that was added for future scalability.
When this command is extended with new fields, we'll add a bit for those fields.
The comp_mask field will indicate which extra fields are contained in the command.
Therefore, for the first version of this uverb command, no use for this field is needed.

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