Added some initial support for a userspace server to receive requests.

4 files changed, 472 insertions, 0 deletions

diff --git a/userspace/ncr-server/Makefile b/userspace/ncr-server/Makefile
new file mode 100644
index 0000000..ee46dd6
--- /dev/null
+++ b/userspace/ncr-server/Makefile
@@ -0,0 +1,7 @@
+all: ncr-server
+
+CFLAGS=-O2 -Wall -g -I.. -I.
+CC=gcc
+
+ncr-server: ncr-server.c ncr-server.h
+	$(CC) $(CFLAGS) ncr-server.c -o ncr-server 
diff --git a/userspace/ncr-server/list.h b/userspace/ncr-server/list.h
new file mode 100644
index 0000000..3a76885
--- /dev/null
+++ b/userspace/ncr-server/list.h
@@ -0,0 +1,244 @@
+#ifndef __LIST_H
+#define __LIST_H
+
+/* This file is from Linux Kernel (include/linux/list.h) 
+ * and modified by simply removing hardware prefetching of list items. 
+ * Here by copyright, credits attributed to wherever they belong.
+ * Kulesh Shanmugasundaram (kulesh [squiggly] isis.poly.edu)
+ */
+
+/*
+ * Simple doubly linked list implementation.
+ *
+ * Some of the internal functions ("__xxx") are useful when
+ * manipulating whole lists rather than single entries, as
+ * sometimes we already know the next/prev entries and we can
+ * generate better code by using them directly rather than
+ * using the generic single-entry routines.
+ */
+
+struct list_head {
+	struct list_head *next, *prev;
+};
+
+#define LIST_HEAD_INIT(name) { &(name), &(name) }
+
+#define LIST_HEAD(name) \
+	struct list_head name = LIST_HEAD_INIT(name)
+
+#define INIT_LIST_HEAD(ptr) do { \
+	(ptr)->next = (ptr); (ptr)->prev = (ptr); \
+} while (0)
+
+/*
+ * Insert a new entry between two known consecutive entries. 
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_add(struct list_head *new,
+			      struct list_head *prev,
+			      struct list_head *next)
+{
+	next->prev = new;
+	new->next = next;
+	new->prev = prev;
+	prev->next = new;
+}
+
+/**
+ * list_add - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ */
+static inline void list_add(struct list_head *new, struct list_head *head)
+{
+	__list_add(new, head, head->next);
+}
+
+/**
+ * list_add_tail - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it before
+ *
+ * Insert a new entry before the specified head.
+ * This is useful for implementing queues.
+ */
+static inline void list_add_tail(struct list_head *new, struct list_head *head)
+{
+	__list_add(new, head->prev, head);
+}
+
+/*
+ * Delete a list entry by making the prev/next entries
+ * point to each other.
+ *
+ * This is only for internal list manipulation where we know
+ * the prev/next entries already!
+ */
+static inline void __list_del(struct list_head *prev, struct list_head *next)
+{
+	next->prev = prev;
+	prev->next = next;
+}
+
+/**
+ * list_del - deletes entry from list.
+ * @entry: the element to delete from the list.
+ * Note: list_empty on entry does not return true after this, the entry is in an undefined state.
+ */
+static inline void list_del(struct list_head *entry)
+{
+	__list_del(entry->prev, entry->next);
+	entry->next = (void *) 0;
+	entry->prev = (void *) 0;
+}
+
+/**
+ * list_del_init - deletes entry from list and reinitialize it.
+ * @entry: the element to delete from the list.
+ */
+static inline void list_del_init(struct list_head *entry)
+{
+	__list_del(entry->prev, entry->next);
+	INIT_LIST_HEAD(entry); 
+}
+
+/**
+ * list_move - delete from one list and add as another's head
+ * @list: the entry to move
+ * @head: the head that will precede our entry
+ */
+static inline void list_move(struct list_head *list, struct list_head *head)
+{
+        __list_del(list->prev, list->next);
+        list_add(list, head);
+}
+
+/**
+ * list_move_tail - delete from one list and add as another's tail
+ * @list: the entry to move
+ * @head: the head that will follow our entry
+ */
+static inline void list_move_tail(struct list_head *list,
+				  struct list_head *head)
+{
+        __list_del(list->prev, list->next);
+        list_add_tail(list, head);
+}
+
+/**
+ * list_empty - tests whether a list is empty
+ * @head: the list to test.
+ */
+static inline int list_empty(struct list_head *head)
+{
+	return head->next == head;
+}
+
+static inline void __list_splice(struct list_head *list,
+				 struct list_head *head)
+{
+	struct list_head *first = list->next;
+	struct list_head *last = list->prev;
+	struct list_head *at = head->next;
+
+	first->prev = head;
+	head->next = first;
+
+	last->next = at;
+	at->prev = last;
+}
+
+/**
+ * list_splice - join two lists
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ */
+static inline void list_splice(struct list_head *list, struct list_head *head)
+{
+	if (!list_empty(list))
+		__list_splice(list, head);
+}
+
+/**
+ * list_splice_init - join two lists and reinitialise the emptied list.
+ * @list: the new list to add.
+ * @head: the place to add it in the first list.
+ *
+ * The list at @list is reinitialised
+ */
+static inline void list_splice_init(struct list_head *list,
+				    struct list_head *head)
+{
+	if (!list_empty(list)) {
+		__list_splice(list, head);
+		INIT_LIST_HEAD(list);
+	}
+}
+
+/**
+ * list_entry - get the struct for this entry
+ * @ptr:	the &struct list_head pointer.
+ * @type:	the type of the struct this is embedded in.
+ * @member:	the name of the list_struct within the struct.
+ */
+#define list_entry(ptr, type, member) \
+	((type *)((char *)(ptr)-(unsigned long)(&((type *)0)->member)))
+
+/**
+ * list_for_each	-	iterate over a list
+ * @pos:	the &struct list_head to use as a loop counter.
+ * @head:	the head for your list.
+ */
+#define list_for_each(pos, head) \
+	for (pos = (head)->next; pos != (head); \
+        	pos = pos->next)
+/**
+ * list_for_each_prev	-	iterate over a list backwards
+ * @pos:	the &struct list_head to use as a loop counter.
+ * @head:	the head for your list.
+ */
+#define list_for_each_prev(pos, head) \
+	for (pos = (head)->prev; pos != (head); \
+        	pos = pos->prev)
+        	
+/**
+ * list_for_each_safe	-	iterate over a list safe against removal of list entry
+ * @pos:	the &struct list_head to use as a loop counter.
+ * @n:		another &struct list_head to use as temporary storage
+ * @head:	the head for your list.
+ */
+#define list_for_each_safe(pos, n, head) \
+	for (pos = (head)->next, n = pos->next; pos != (head); \
+		pos = n, n = pos->next)
+
+/**
+ * list_for_each_entry	-	iterate over list of given type
+ * @pos:	the type * to use as a loop counter.
+ * @head:	the head for your list.
+ * @member:	the name of the list_struct within the struct.
+ */
+#define list_for_each_entry(pos, head, member)				\
+	for (pos = list_entry((head)->next, typeof(*pos), member);	\
+	     &pos->member != (head); 					\
+	     pos = list_entry(pos->member.next, typeof(*pos), member))
+
+/**
+ * list_for_each_entry_safe - iterate over list of given type safe against removal of list entry
+ * @pos:	the type * to use as a loop counter.
+ * @n:		another type * to use as temporary storage
+ * @head:	the head for your list.
+ * @member:	the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_safe(pos, n, head, member)			\
+	for (pos = list_entry((head)->next, typeof(*pos), member),	\
+		n = list_entry(pos->member.next, typeof(*pos), member);	\
+	     &pos->member != (head); 					\
+	     pos = n, n = list_entry(n->member.next, typeof(*n), member))
+
+
+#endif
diff --git a/userspace/ncr-server/ncr-server.c b/userspace/ncr-server/ncr-server.c
new file mode 100644
index 0000000..3b3c72a
--- /dev/null
+++ b/userspace/ncr-server/ncr-server.c
@@ -0,0 +1,210 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <netlink/netlink.h>
+#include <netlink/socket.h>
+#include <netlink/genl/genl.h>
+#include <netlink/genl/ctrl.h>
+#include "../ncr-storage-low.h"
+#include "ncr-server.h"
+#include <list.h>
+
+static int _notify_listening(struct nl_sock * sock);
+
+static struct nla_policy def_policy[ATTR_MAX+1] =
+{
+     [ATTR_STRUCT_STORE] = { .type = NLA_UNSPEC,
+                          .minlen = sizeof(struct storage_item_st) },
+     [ATTR_STRUCT_LOAD] = { .type = NLA_UNSPEC,
+                          .minlen = sizeof(struct ncr_gnl_load_cmd_st) },
+};
+
+static struct actions {
+	list_head list;
+	int cmd; /* CMD_* */
+	union {
+		struct storage_item_st tostore;
+		struct ncr_gnl_load_cmd_st toload;
+	} data;
+} todo;
+
+static int add_store_cmd(struct storage_item_st* tostore)
+{
+	struct actions* item;
+
+	item = malloc(sizeof(*item));
+	if (item == NULL) {
+		err();
+		return -ERR_MEM;
+	}
+	item->cmd = CMD_STORE;
+	memcpy(item->data.tostore, tostore, sizeof(item->data.tostore));
+
+	list_add(item, &todo.list);
+	return 0;
+}
+
+static int add_load_cmd(struct ncr_gnl_load_cmd_st* toload)
+{
+	struct actions* item;
+
+	item = malloc(sizeof(*item));
+	if (item == NULL) {
+		err();
+		return -ERR_MEM;
+	}
+	item->cmd = CMD_LOAD;
+	memcpy(item->data.toload, toload, sizeof(item->data.toload));
+
+	list_add(item, &todo.list);
+	return 0;
+}
+
+static int msg_cb(struct nl_msg *msg, void *arg)
+{
+	struct nlmsghdr *nlh = nlmsg_hdr(msg);
+	struct nlattr *attrs[ATTR_MAX+1];
+
+		// Validate message and parse attributes
+	genlmsg_parse(nlh, 0, attrs, ATTR_MAX, def_policy);
+
+	if (attrs[ATTR_STRUCT_STORE]) {
+		struct storage_item_st *item = nla_get(attrs[ATTR_STRUCT_STORE]);
+		fprintf(stderr, "asked to store: %s\n", item->label);
+
+		add_store_cmd(item);
+	}
+
+	if (attrs[ATTR_STRUCT_LOAD]) {
+		struct ncr_gnl_load_cmd_st *load = nla_get(attrs[ATTR_STRUCT_LOAD]);
+		fprintf(stderr, "asked to load: %s\n", load->label);
+
+		add_load_cmd(item);
+	}
+
+	return NL_STOP;
+}
+
+
+int main()
+{
+struct nl_sock *sock;
+int ret;
+
+	memset(&todo, 0, sizeof(todo));
+	LIST_HEAD_INIT(&todo.list);
+
+	// Allocate a new netlink socket
+	sock = nl_socket_alloc();
+	if (sock == NULL) {
+		err();
+		return ERR_CONNECT;
+	}
+
+	// Connect to generic netlink socket on kernel side
+	ret = genl_connect(sock);
+	if (ret < 0) {
+		err();
+		return ERR_CONNECT;
+	}
+	
+	// Ask kernel to resolve family name to family id
+	family = genl_ctrl_resolve(sock, NCR_NL_STORAGE_NAME);
+	if (family < 0) {
+		err();
+		return ERR_CONNECT;
+	}
+
+	/* set our callback to receive messages */
+	ret = nl_socket_modify_cb(sock, NL_CB_VALID, NL_CB_CUSTOM, msg_cb, NULL);
+	if (ret < 0) {
+		fprintf(stderr, "Could not set listening callback.\n");
+		exit(1);
+	}
+
+	ret = _notify_listening(sock);
+	if (ret < 0) {
+		fprintf(stderr, "Could not notify kernel subsystem.\n");
+		exit(1);
+	}
+
+	// Wait for the answer and receive it
+	do {
+		ret = nl_recvmsgs_default(sock);
+
+		/* we have to consume the todo list */
+		if (ret == 0) {
+			//store_if_needed(sock);
+			//load_if_needed(sock);
+		}
+	} while (ret == 0);
+	fprintf(stderr, "received: %d\n", ret);
+
+}
+
+static int _notify_listening(struct nl_sock * sock)
+{
+struct nl_msg *msg;
+int family, ret;
+
+	// Construct a generic netlink by allocating a new message, fill in
+	// the header and append a simple integer attribute.
+	msg = nlmsg_alloc();
+	if (msg == NULL) {
+		err();
+		return ERR_MEM;
+	}
+
+	genlmsg_put(msg, NL_AUTO_PID, NL_AUTO_SEQ, family, 0, NLM_F_REQUEST,
+	 CMD_LISTENING, NCR_NL_STORAGE_VERSION);
+
+	// Send message over netlink socket
+	ret = nl_send_auto_complete(sock, msg);
+	nlmsg_free(msg);
+
+	if (ret < 0) {
+		err();
+		return ERR_CONNECT;
+	}
+
+	return 0;
+}
+
+
+static int send_store_ack(struct nl_sock * sock, uint8_t val)
+{
+struct nl_msg *msg;
+int family, ret;
+
+	// Construct a generic netlink by allocating a new message, fill in
+	// the header and append a simple integer attribute.
+	msg = nlmsg_alloc();
+	if (msg == NULL) {
+		err();
+		return ERR_MEM;
+	}
+
+	genlmsg_put(msg, NL_AUTO_PID, NL_AUTO_SEQ, family, 0, NLM_F_REQUEST,
+	 CMD_STORE_ACK, NCR_NL_STORAGE_VERSION);
+
+	ret = nla_put_u8(msg, ATTR_STORE_ACK, val);
+	if (ret < 0) {
+		err();
+		ret = ERR_SEND;
+		goto fail;
+	}
+
+	// Send message over netlink socket
+	ret = nl_send_auto_complete(sock, msg);
+	nlmsg_free(msg);
+
+	if (ret < 0) {
+		err();
+		return ERR_SEND;
+	}
+
+	return 0;
+fail:
+	nlmsg_free(msg);
+	return ret;
+}
diff --git a/userspace/ncr-server/ncr-server.h b/userspace/ncr-server/ncr-server.h
new file mode 100644
index 0000000..dae0757
--- /dev/null
+++ b/userspace/ncr-server/ncr-server.h
@@ -0,0 +1,11 @@
+#ifndef NCR_SERVER_H
+#define NCR_SERVER_H
+
+#define err() fprintf(stderr, "Error in %s:%d\n", __FILE__, __LINE__);
+
+#define ERR_CONNECT -1
+#define ERR_MEM -2
+#define ERR_SEND -3
+
+
+#endif