added vrpmdv-rtservice, vrpmdv-mon-datafile,

vrpmdv-monitoring-controler, vrpmdv-mon-tty

recipes-vrpmdv/recipes-base/vrpmdv-monitoring-controler/files/vrpmdv-monitoring-cmd.h

@@ -0,0 +1,98 @@
+/* Copyright 2021 Philipp Schuster
+ *
+ * This Software is owned by Markus Lehr.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+ * INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A 
+ * PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#pragma once
+
+/*
+ * This file describes the common properties of our custom Netlink family on top of Generic Netlink.
+ * It is used by all C projects, i.e. the Kernel driver, and the userland components.
+ */
+
+/**
+ * Generic Netlink will create a Netlink family with this name. Kernel will asign
+ * a numeric ID and afterwards we can talk to the family with its ID. To get
+ * the ID we use Generic Netlink in the userland and pass the family name.
+ *
+ * Short for: Generic Netlink VRPMDV Monitoring  gnl_foobar_mcmd
+ */
+#define FAMILY_NAME "gnl-vrpmdv-mcmd"
+
+/**
+ * These are the attributes that we want to share in gnl_foobar_xmpl.
+ * You can understand an attribute as a semantic type. This is
+ * the payload of Netlink messages.
+ * GNl: Generic Netlink
+ */
+enum GNL_VRPMDV_XMPL_ATTRIBUTE {
+    /**
+     * 0 is never used (=> UNSPEC), you can also see this in other family definitions in Linux code.
+     * We do the same, although I'm not sure, if this is really enforced by code.
+     */
+    GNL_VRPMDV_MCMD_A_UNSPEC,
+    /** We expect a MSG to be a null-terminated C-string. */
+    GNL_VRPMDV_MCMD_A_MSG,
+    /** Unused marker field to get the length/count of enum entries. No real attribute. */
+    __GNL_VRPMDV_MCMD_A_MAX,
+};
+/**
+ * Number of elements in `enum GNL_VRPMDV_MCMD_COMMAND`.
+ */
+#define GNL_FOOBAR_XMPL_ATTRIBUTE_ENUM_LEN (__GNL_VRPMDV_MCMD_A_MAX)
+/**
+ * The number of actual usable attributes in `enum GNL_VRPMDV_MCMD_ATTRIBUTE`.
+ * This is `GNL_VRPMDV_MCMD_ATTRIBUTE_ENUM_LEN` - 1 because "UNSPEC" is never used.
+ */
+#define GNL_VRPMDV_MCMD_ATTRIBUTE_COUNT (GNL_VRPMDV_MCMD_ATTRIBUTE_ENUM_LEN - 1)
+
+/**
+ * Enumeration of all commands (functions) that our custom protocol on top
+ * of generic netlink supports. This can be understood as the action that
+ * we want to trigger on the receiving side.
+ */
+enum GNL_VRPMDV_MCMD_COMMAND {
+    /**
+     * 0 is never used (=> UNSPEC), you can also see this in other family definitions in Linux code.
+     * We do the same, although I'm not sure, if this is really enforced by code.
+     */
+    GNL_VRPMDV_MCMD_C_UNSPEC,
+
+    // first real command is "1" (>0)
+    /**
+     * When this command is received, we expect the attribute `GNL_VRPMDV_MCMD_ATTRIBUTE::GNL_VRPMDV_MCMD_A_MSG` to
+     * be present in the Generic Netlink request message. The kernel reads the message from the packet and
+     * sent it to the copro. THe result will be return by creating a new Generic Netlink response message 
+     * with an corresponding attribute/payload.
+     *
+     * This command/signaling mechanism is independent of the Netlink flag `NLM_F_ECHO (0x08)`. We use it as
+     * "echo specific data" instead of return a 1:1 copy of the package, which you could do with
+     * `NLM_F_ECHO (0x08)` for example.
+     */
+    GNL_VRPMDV_MCMD_C_MSG,
+
+    /**
+     * Provokes a NLMSG_ERR answer to this request as described in netlink manpage
+     * (https://man7.org/linux/man-pages/man7/netlink.7.html).
+     */
+    GNL_VRPMDV_MCMD_C_REPLY_WITH_NLMSG_ERR,
+
+    /** Unused marker field to get the length/count of enum entries. No real attribute. */
+    __GNL_VRPMDV_MCMD_C_MAX,
+};
+/**
+ * Number of elements in `enum GNL_VRPMDV_MCMD_COMMAND`.
+ */
+#define GNL_VRPMDV_MCMD_COMMAND_ENUM_LEN (__GNL_VRPMDV_MCMD_C_MAX)
+/**
+ * The number of actual usable commands  in `enum GNL_FOOBAR_XMPL_COMMAND`.
+ * This is `GNL_VRPMDV_MCMD_COMMAND_ENUM_LEN` - 1 because "UNSPEC" is never used.
+ */
+#define GNL_VRPMDV_MCMD_COMMAND_COUNT (GNL_VRPMDV_MCMD_COMMAND_ENUM_LEN - 1)