net/802: Implement Multiple Registration Protocol (MRP)
authorDavid Ward <david.ward@ll.mit.edu>
Fri, 8 Feb 2013 17:17:06 +0000 (17:17 +0000)
committerDavid S. Miller <davem@davemloft.net>
Mon, 11 Feb 2013 01:37:22 +0000 (20:37 -0500)
Initial implementation of the Multiple Registration Protocol (MRP)
from IEEE 802.1Q-2011, based on the existing implementation of the
Generic Attribute Registration Protocol (GARP).

Signed-off-by: David Ward <david.ward@ll.mit.edu>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
include/linux/netdevice.h
include/net/mrp.h [new file with mode: 0644]
net/802/Kconfig
net/802/Makefile
net/802/mrp.c [new file with mode: 0644]

index ab2774e..25bd46f 100644 (file)
@@ -1290,6 +1290,8 @@ struct net_device {
        };
        /* GARP */
        struct garp_port __rcu  *garp_port;
+       /* MRP */
+       struct mrp_port __rcu   *mrp_port;
 
        /* class/net/name entry */
        struct device           dev;
diff --git a/include/net/mrp.h b/include/net/mrp.h
new file mode 100644 (file)
index 0000000..4fbf02a
--- /dev/null
@@ -0,0 +1,143 @@
+#ifndef _NET_MRP_H
+#define _NET_MRP_H
+
+#define MRP_END_MARK           0x0
+
+struct mrp_pdu_hdr {
+       u8      version;
+};
+
+struct mrp_msg_hdr {
+       u8      attrtype;
+       u8      attrlen;
+};
+
+struct mrp_vecattr_hdr {
+       __be16  lenflags;
+       unsigned char   firstattrvalue[];
+#define MRP_VECATTR_HDR_LEN_MASK cpu_to_be16(0x1FFF)
+#define MRP_VECATTR_HDR_FLAG_LA cpu_to_be16(0x2000)
+};
+
+enum mrp_vecattr_event {
+       MRP_VECATTR_EVENT_NEW,
+       MRP_VECATTR_EVENT_JOIN_IN,
+       MRP_VECATTR_EVENT_IN,
+       MRP_VECATTR_EVENT_JOIN_MT,
+       MRP_VECATTR_EVENT_MT,
+       MRP_VECATTR_EVENT_LV,
+       __MRP_VECATTR_EVENT_MAX
+};
+
+struct mrp_skb_cb {
+       struct mrp_msg_hdr      *mh;
+       struct mrp_vecattr_hdr  *vah;
+       unsigned char           attrvalue[];
+};
+
+static inline struct mrp_skb_cb *mrp_cb(struct sk_buff *skb)
+{
+       BUILD_BUG_ON(sizeof(struct mrp_skb_cb) >
+                    FIELD_SIZEOF(struct sk_buff, cb));
+       return (struct mrp_skb_cb *)skb->cb;
+}
+
+enum mrp_applicant_state {
+       MRP_APPLICANT_INVALID,
+       MRP_APPLICANT_VO,
+       MRP_APPLICANT_VP,
+       MRP_APPLICANT_VN,
+       MRP_APPLICANT_AN,
+       MRP_APPLICANT_AA,
+       MRP_APPLICANT_QA,
+       MRP_APPLICANT_LA,
+       MRP_APPLICANT_AO,
+       MRP_APPLICANT_QO,
+       MRP_APPLICANT_AP,
+       MRP_APPLICANT_QP,
+       __MRP_APPLICANT_MAX
+};
+#define MRP_APPLICANT_MAX      (__MRP_APPLICANT_MAX - 1)
+
+enum mrp_event {
+       MRP_EVENT_NEW,
+       MRP_EVENT_JOIN,
+       MRP_EVENT_LV,
+       MRP_EVENT_TX,
+       MRP_EVENT_R_NEW,
+       MRP_EVENT_R_JOIN_IN,
+       MRP_EVENT_R_IN,
+       MRP_EVENT_R_JOIN_MT,
+       MRP_EVENT_R_MT,
+       MRP_EVENT_R_LV,
+       MRP_EVENT_R_LA,
+       MRP_EVENT_REDECLARE,
+       MRP_EVENT_PERIODIC,
+       __MRP_EVENT_MAX
+};
+#define MRP_EVENT_MAX          (__MRP_EVENT_MAX - 1)
+
+enum mrp_tx_action {
+       MRP_TX_ACTION_NONE,
+       MRP_TX_ACTION_S_NEW,
+       MRP_TX_ACTION_S_JOIN_IN,
+       MRP_TX_ACTION_S_JOIN_IN_OPTIONAL,
+       MRP_TX_ACTION_S_IN_OPTIONAL,
+       MRP_TX_ACTION_S_LV,
+};
+
+struct mrp_attr {
+       struct rb_node                  node;
+       enum mrp_applicant_state        state;
+       u8                              type;
+       u8                              len;
+       unsigned char                   value[];
+};
+
+enum mrp_applications {
+       MRP_APPLICATION_MVRP,
+       __MRP_APPLICATION_MAX
+};
+#define MRP_APPLICATION_MAX    (__MRP_APPLICATION_MAX - 1)
+
+struct mrp_application {
+       enum mrp_applications   type;
+       unsigned int            maxattr;
+       struct packet_type      pkttype;
+       unsigned char           group_address[ETH_ALEN];
+       u8                      version;
+};
+
+struct mrp_applicant {
+       struct mrp_application  *app;
+       struct net_device       *dev;
+       struct timer_list       join_timer;
+
+       spinlock_t              lock;
+       struct sk_buff_head     queue;
+       struct sk_buff          *pdu;
+       struct rb_root          mad;
+       struct rcu_head         rcu;
+};
+
+struct mrp_port {
+       struct mrp_applicant __rcu      *applicants[MRP_APPLICATION_MAX + 1];
+       struct rcu_head                 rcu;
+};
+
+extern int     mrp_register_application(struct mrp_application *app);
+extern void    mrp_unregister_application(struct mrp_application *app);
+
+extern int     mrp_init_applicant(struct net_device *dev,
+                                   struct mrp_application *app);
+extern void    mrp_uninit_applicant(struct net_device *dev,
+                                     struct mrp_application *app);
+
+extern int     mrp_request_join(const struct net_device *dev,
+                                 const struct mrp_application *app,
+                                 const void *value, u8 len, u8 type);
+extern void    mrp_request_leave(const struct net_device *dev,
+                                  const struct mrp_application *app,
+                                  const void *value, u8 len, u8 type);
+
+#endif /* _NET_MRP_H */
index be33d27..80d4bf7 100644 (file)
@@ -5,3 +5,6 @@ config STP
 config GARP
        tristate
        select STP
+
+config MRP
+       tristate
index a30d6e3..37e654d 100644 (file)
@@ -11,3 +11,4 @@ obj-$(CONFIG_IPX)     += p8022.o psnap.o p8023.o
 obj-$(CONFIG_ATALK)    += p8022.o psnap.o
 obj-$(CONFIG_STP)      += stp.o
 obj-$(CONFIG_GARP)     += garp.o
+obj-$(CONFIG_MRP)      += mrp.o
diff --git a/net/802/mrp.c b/net/802/mrp.c
new file mode 100644 (file)
index 0000000..47a9e14
--- /dev/null
@@ -0,0 +1,895 @@
+/*
+ *     IEEE 802.1Q Multiple Registration Protocol (MRP)
+ *
+ *     Copyright (c) 2012 Massachusetts Institute of Technology
+ *
+ *     Adapted from code in net/802/garp.c
+ *     Copyright (c) 2008 Patrick McHardy <kaber@trash.net>
+ *
+ *     This program is free software; you can redistribute it and/or
+ *     modify it under the terms of the GNU General Public License
+ *     version 2 as published by the Free Software Foundation.
+ */
+#include <linux/kernel.h>
+#include <linux/timer.h>
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <net/mrp.h>
+#include <asm/unaligned.h>
+
+static unsigned int mrp_join_time __read_mostly = 200;
+module_param(mrp_join_time, uint, 0644);
+MODULE_PARM_DESC(mrp_join_time, "Join time in ms (default 200ms)");
+MODULE_LICENSE("GPL");
+
+static const u8
+mrp_applicant_state_table[MRP_APPLICANT_MAX + 1][MRP_EVENT_MAX + 1] = {
+       [MRP_APPLICANT_VO] = {
+               [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
+               [MRP_EVENT_JOIN]        = MRP_APPLICANT_VP,
+               [MRP_EVENT_LV]          = MRP_APPLICANT_VO,
+               [MRP_EVENT_TX]          = MRP_APPLICANT_VO,
+               [MRP_EVENT_R_NEW]       = MRP_APPLICANT_VO,
+               [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_AO,
+               [MRP_EVENT_R_IN]        = MRP_APPLICANT_VO,
+               [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_VO,
+               [MRP_EVENT_R_MT]        = MRP_APPLICANT_VO,
+               [MRP_EVENT_R_LV]        = MRP_APPLICANT_VO,
+               [MRP_EVENT_R_LA]        = MRP_APPLICANT_VO,
+               [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VO,
+               [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_VO,
+       },
+       [MRP_APPLICANT_VP] = {
+               [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
+               [MRP_EVENT_JOIN]        = MRP_APPLICANT_VP,
+               [MRP_EVENT_LV]          = MRP_APPLICANT_VO,
+               [MRP_EVENT_TX]          = MRP_APPLICANT_AA,
+               [MRP_EVENT_R_NEW]       = MRP_APPLICANT_VP,
+               [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_AP,
+               [MRP_EVENT_R_IN]        = MRP_APPLICANT_VP,
+               [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_VP,
+               [MRP_EVENT_R_MT]        = MRP_APPLICANT_VP,
+               [MRP_EVENT_R_LV]        = MRP_APPLICANT_VP,
+               [MRP_EVENT_R_LA]        = MRP_APPLICANT_VP,
+               [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VP,
+               [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_VP,
+       },
+       [MRP_APPLICANT_VN] = {
+               [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
+               [MRP_EVENT_JOIN]        = MRP_APPLICANT_VN,
+               [MRP_EVENT_LV]          = MRP_APPLICANT_LA,
+               [MRP_EVENT_TX]          = MRP_APPLICANT_AN,
+               [MRP_EVENT_R_NEW]       = MRP_APPLICANT_VN,
+               [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_VN,
+               [MRP_EVENT_R_IN]        = MRP_APPLICANT_VN,
+               [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_VN,
+               [MRP_EVENT_R_MT]        = MRP_APPLICANT_VN,
+               [MRP_EVENT_R_LV]        = MRP_APPLICANT_VN,
+               [MRP_EVENT_R_LA]        = MRP_APPLICANT_VN,
+               [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VN,
+               [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_VN,
+       },
+       [MRP_APPLICANT_AN] = {
+               [MRP_EVENT_NEW]         = MRP_APPLICANT_AN,
+               [MRP_EVENT_JOIN]        = MRP_APPLICANT_AN,
+               [MRP_EVENT_LV]          = MRP_APPLICANT_LA,
+               [MRP_EVENT_TX]          = MRP_APPLICANT_QA,
+               [MRP_EVENT_R_NEW]       = MRP_APPLICANT_AN,
+               [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_AN,
+               [MRP_EVENT_R_IN]        = MRP_APPLICANT_AN,
+               [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AN,
+               [MRP_EVENT_R_MT]        = MRP_APPLICANT_AN,
+               [MRP_EVENT_R_LV]        = MRP_APPLICANT_VN,
+               [MRP_EVENT_R_LA]        = MRP_APPLICANT_VN,
+               [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VN,
+               [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AN,
+       },
+       [MRP_APPLICANT_AA] = {
+               [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
+               [MRP_EVENT_JOIN]        = MRP_APPLICANT_AA,
+               [MRP_EVENT_LV]          = MRP_APPLICANT_LA,
+               [MRP_EVENT_TX]          = MRP_APPLICANT_QA,
+               [MRP_EVENT_R_NEW]       = MRP_APPLICANT_AA,
+               [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QA,
+               [MRP_EVENT_R_IN]        = MRP_APPLICANT_AA,
+               [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AA,
+               [MRP_EVENT_R_MT]        = MRP_APPLICANT_AA,
+               [MRP_EVENT_R_LV]        = MRP_APPLICANT_VP,
+               [MRP_EVENT_R_LA]        = MRP_APPLICANT_VP,
+               [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VP,
+               [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AA,
+       },
+       [MRP_APPLICANT_QA] = {
+               [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
+               [MRP_EVENT_JOIN]        = MRP_APPLICANT_QA,
+               [MRP_EVENT_LV]          = MRP_APPLICANT_LA,
+               [MRP_EVENT_TX]          = MRP_APPLICANT_QA,
+               [MRP_EVENT_R_NEW]       = MRP_APPLICANT_QA,
+               [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QA,
+               [MRP_EVENT_R_IN]        = MRP_APPLICANT_QA,
+               [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AA,
+               [MRP_EVENT_R_MT]        = MRP_APPLICANT_AA,
+               [MRP_EVENT_R_LV]        = MRP_APPLICANT_VP,
+               [MRP_EVENT_R_LA]        = MRP_APPLICANT_VP,
+               [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VP,
+               [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AA,
+       },
+       [MRP_APPLICANT_LA] = {
+               [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
+               [MRP_EVENT_JOIN]        = MRP_APPLICANT_AA,
+               [MRP_EVENT_LV]          = MRP_APPLICANT_LA,
+               [MRP_EVENT_TX]          = MRP_APPLICANT_VO,
+               [MRP_EVENT_R_NEW]       = MRP_APPLICANT_LA,
+               [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_LA,
+               [MRP_EVENT_R_IN]        = MRP_APPLICANT_LA,
+               [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_LA,
+               [MRP_EVENT_R_MT]        = MRP_APPLICANT_LA,
+               [MRP_EVENT_R_LV]        = MRP_APPLICANT_LA,
+               [MRP_EVENT_R_LA]        = MRP_APPLICANT_LA,
+               [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_LA,
+               [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_LA,
+       },
+       [MRP_APPLICANT_AO] = {
+               [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
+               [MRP_EVENT_JOIN]        = MRP_APPLICANT_AP,
+               [MRP_EVENT_LV]          = MRP_APPLICANT_AO,
+               [MRP_EVENT_TX]          = MRP_APPLICANT_AO,
+               [MRP_EVENT_R_NEW]       = MRP_APPLICANT_AO,
+               [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QO,
+               [MRP_EVENT_R_IN]        = MRP_APPLICANT_AO,
+               [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AO,
+               [MRP_EVENT_R_MT]        = MRP_APPLICANT_AO,
+               [MRP_EVENT_R_LV]        = MRP_APPLICANT_VO,
+               [MRP_EVENT_R_LA]        = MRP_APPLICANT_VO,
+               [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VO,
+               [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AO,
+       },
+       [MRP_APPLICANT_QO] = {
+               [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
+               [MRP_EVENT_JOIN]        = MRP_APPLICANT_QP,
+               [MRP_EVENT_LV]          = MRP_APPLICANT_QO,
+               [MRP_EVENT_TX]          = MRP_APPLICANT_QO,
+               [MRP_EVENT_R_NEW]       = MRP_APPLICANT_QO,
+               [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QO,
+               [MRP_EVENT_R_IN]        = MRP_APPLICANT_QO,
+               [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AO,
+               [MRP_EVENT_R_MT]        = MRP_APPLICANT_AO,
+               [MRP_EVENT_R_LV]        = MRP_APPLICANT_VO,
+               [MRP_EVENT_R_LA]        = MRP_APPLICANT_VO,
+               [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VO,
+               [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_QO,
+       },
+       [MRP_APPLICANT_AP] = {
+               [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
+               [MRP_EVENT_JOIN]        = MRP_APPLICANT_AP,
+               [MRP_EVENT_LV]          = MRP_APPLICANT_AO,
+               [MRP_EVENT_TX]          = MRP_APPLICANT_QA,
+               [MRP_EVENT_R_NEW]       = MRP_APPLICANT_AP,
+               [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QP,
+               [MRP_EVENT_R_IN]        = MRP_APPLICANT_AP,
+               [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AP,
+               [MRP_EVENT_R_MT]        = MRP_APPLICANT_AP,
+               [MRP_EVENT_R_LV]        = MRP_APPLICANT_VP,
+               [MRP_EVENT_R_LA]        = MRP_APPLICANT_VP,
+               [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VP,
+               [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AP,
+       },
+       [MRP_APPLICANT_QP] = {
+               [MRP_EVENT_NEW]         = MRP_APPLICANT_VN,
+               [MRP_EVENT_JOIN]        = MRP_APPLICANT_QP,
+               [MRP_EVENT_LV]          = MRP_APPLICANT_QO,
+               [MRP_EVENT_TX]          = MRP_APPLICANT_QP,
+               [MRP_EVENT_R_NEW]       = MRP_APPLICANT_QP,
+               [MRP_EVENT_R_JOIN_IN]   = MRP_APPLICANT_QP,
+               [MRP_EVENT_R_IN]        = MRP_APPLICANT_QP,
+               [MRP_EVENT_R_JOIN_MT]   = MRP_APPLICANT_AP,
+               [MRP_EVENT_R_MT]        = MRP_APPLICANT_AP,
+               [MRP_EVENT_R_LV]        = MRP_APPLICANT_VP,
+               [MRP_EVENT_R_LA]        = MRP_APPLICANT_VP,
+               [MRP_EVENT_REDECLARE]   = MRP_APPLICANT_VP,
+               [MRP_EVENT_PERIODIC]    = MRP_APPLICANT_AP,
+       },
+};
+
+static const u8
+mrp_tx_action_table[MRP_APPLICANT_MAX + 1] = {
+       [MRP_APPLICANT_VO] = MRP_TX_ACTION_S_IN_OPTIONAL,
+       [MRP_APPLICANT_VP] = MRP_TX_ACTION_S_JOIN_IN,
+       [MRP_APPLICANT_VN] = MRP_TX_ACTION_S_NEW,
+       [MRP_APPLICANT_AN] = MRP_TX_ACTION_S_NEW,
+       [MRP_APPLICANT_AA] = MRP_TX_ACTION_S_JOIN_IN,
+       [MRP_APPLICANT_QA] = MRP_TX_ACTION_S_JOIN_IN_OPTIONAL,
+       [MRP_APPLICANT_LA] = MRP_TX_ACTION_S_LV,
+       [MRP_APPLICANT_AO] = MRP_TX_ACTION_S_IN_OPTIONAL,
+       [MRP_APPLICANT_QO] = MRP_TX_ACTION_S_IN_OPTIONAL,
+       [MRP_APPLICANT_AP] = MRP_TX_ACTION_S_JOIN_IN,
+       [MRP_APPLICANT_QP] = MRP_TX_ACTION_S_IN_OPTIONAL,
+};
+
+static void mrp_attrvalue_inc(void *value, u8 len)
+{
+       u8 *v = (u8 *)value;
+
+       /* Add 1 to the last byte. If it becomes zero,
+        * go to the previous byte and repeat.
+        */
+       while (len > 0 && !++v[--len])
+               ;
+}
+
+static int mrp_attr_cmp(const struct mrp_attr *attr,
+                        const void *value, u8 len, u8 type)
+{
+       if (attr->type != type)
+               return attr->type - type;
+       if (attr->len != len)
+               return attr->len - len;
+       return memcmp(attr->value, value, len);
+}
+
+static struct mrp_attr *mrp_attr_lookup(const struct mrp_applicant *app,
+                                       const void *value, u8 len, u8 type)
+{
+       struct rb_node *parent = app->mad.rb_node;
+       struct mrp_attr *attr;
+       int d;
+
+       while (parent) {
+               attr = rb_entry(parent, struct mrp_attr, node);
+               d = mrp_attr_cmp(attr, value, len, type);
+               if (d > 0)
+                       parent = parent->rb_left;
+               else if (d < 0)
+                       parent = parent->rb_right;
+               else
+                       return attr;
+       }
+       return NULL;
+}
+
+static struct mrp_attr *mrp_attr_create(struct mrp_applicant *app,
+                                       const void *value, u8 len, u8 type)
+{
+       struct rb_node *parent = NULL, **p = &app->mad.rb_node;
+       struct mrp_attr *attr;
+       int d;
+
+       while (*p) {
+               parent = *p;
+               attr = rb_entry(parent, struct mrp_attr, node);
+               d = mrp_attr_cmp(attr, value, len, type);
+               if (d > 0)
+                       p = &parent->rb_left;
+               else if (d < 0)
+                       p = &parent->rb_right;
+               else {
+                       /* The attribute already exists; re-use it. */
+                       return attr;
+               }
+       }
+       attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
+       if (!attr)
+               return attr;
+       attr->state = MRP_APPLICANT_VO;
+       attr->type  = type;
+       attr->len   = len;
+       memcpy(attr->value, value, len);
+
+       rb_link_node(&attr->node, parent, p);
+       rb_insert_color(&attr->node, &app->mad);
+       return attr;
+}
+
+static void mrp_attr_destroy(struct mrp_applicant *app, struct mrp_attr *attr)
+{
+       rb_erase(&attr->node, &app->mad);
+       kfree(attr);
+}
+
+static int mrp_pdu_init(struct mrp_applicant *app)
+{
+       struct sk_buff *skb;
+       struct mrp_pdu_hdr *ph;
+
+       skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
+                       GFP_ATOMIC);
+       if (!skb)
+               return -ENOMEM;
+
+       skb->dev = app->dev;
+       skb->protocol = app->app->pkttype.type;
+       skb_reserve(skb, LL_RESERVED_SPACE(app->dev));
+       skb_reset_network_header(skb);
+       skb_reset_transport_header(skb);
+
+       ph = (struct mrp_pdu_hdr *)__skb_put(skb, sizeof(*ph));
+       ph->version = app->app->version;
+
+       app->pdu = skb;
+       return 0;
+}
+
+static int mrp_pdu_append_end_mark(struct mrp_applicant *app)
+{
+       __be16 *endmark;
+
+       if (skb_tailroom(app->pdu) < sizeof(*endmark))
+               return -1;
+       endmark = (__be16 *)__skb_put(app->pdu, sizeof(*endmark));
+       put_unaligned(MRP_END_MARK, endmark);
+       return 0;
+}
+
+static void mrp_pdu_queue(struct mrp_applicant *app)
+{
+       if (!app->pdu)
+               return;
+
+       if (mrp_cb(app->pdu)->mh)
+               mrp_pdu_append_end_mark(app);
+       mrp_pdu_append_end_mark(app);
+
+       dev_hard_header(app->pdu, app->dev, ntohs(app->app->pkttype.type),
+                       app->app->group_address, app->dev->dev_addr,
+                       app->pdu->len);
+
+       skb_queue_tail(&app->queue, app->pdu);
+       app->pdu = NULL;
+}
+
+static void mrp_queue_xmit(struct mrp_applicant *app)
+{
+       struct sk_buff *skb;
+
+       while ((skb = skb_dequeue(&app->queue)))
+               dev_queue_xmit(skb);
+}
+
+static int mrp_pdu_append_msg_hdr(struct mrp_applicant *app,
+                                 u8 attrtype, u8 attrlen)
+{
+       struct mrp_msg_hdr *mh;
+
+       if (mrp_cb(app->pdu)->mh) {
+               if (mrp_pdu_append_end_mark(app) < 0)
+                       return -1;
+               mrp_cb(app->pdu)->mh = NULL;
+               mrp_cb(app->pdu)->vah = NULL;
+       }
+
+       if (skb_tailroom(app->pdu) < sizeof(*mh))
+               return -1;
+       mh = (struct mrp_msg_hdr *)__skb_put(app->pdu, sizeof(*mh));
+       mh->attrtype = attrtype;
+       mh->attrlen = attrlen;
+       mrp_cb(app->pdu)->mh = mh;
+       return 0;
+}
+
+static int mrp_pdu_append_vecattr_hdr(struct mrp_applicant *app,
+                                     const void *firstattrvalue, u8 attrlen)
+{
+       struct mrp_vecattr_hdr *vah;
+
+       if (skb_tailroom(app->pdu) < sizeof(*vah) + attrlen)
+               return -1;
+       vah = (struct mrp_vecattr_hdr *)__skb_put(app->pdu,
+                                                 sizeof(*vah) + attrlen);
+       put_unaligned(0, &vah->lenflags);
+       memcpy(vah->firstattrvalue, firstattrvalue, attrlen);
+       mrp_cb(app->pdu)->vah = vah;
+       memcpy(mrp_cb(app->pdu)->attrvalue, firstattrvalue, attrlen);
+       return 0;
+}
+
+static int mrp_pdu_append_vecattr_event(struct mrp_applicant *app,
+                                       const struct mrp_attr *attr,
+                                       enum mrp_vecattr_event vaevent)
+{
+       u16 len, pos;
+       u8 *vaevents;
+       int err;
+again:
+       if (!app->pdu) {
+               err = mrp_pdu_init(app);
+               if (err < 0)
+                       return err;
+       }
+
+       /* If there is no Message header in the PDU, or the Message header is
+        * for a different attribute type, add an EndMark (if necessary) and a
+        * new Message header to the PDU.
+        */
+       if (!mrp_cb(app->pdu)->mh ||
+           mrp_cb(app->pdu)->mh->attrtype != attr->type ||
+           mrp_cb(app->pdu)->mh->attrlen != attr->len) {
+               if (mrp_pdu_append_msg_hdr(app, attr->type, attr->len) < 0)
+                       goto queue;
+       }
+
+       /* If there is no VectorAttribute header for this Message in the PDU,
+        * or this attribute's value does not sequentially follow the previous
+        * attribute's value, add a new VectorAttribute header to the PDU.
+        */
+       if (!mrp_cb(app->pdu)->vah ||
+           memcmp(mrp_cb(app->pdu)->attrvalue, attr->value, attr->len)) {
+               if (mrp_pdu_append_vecattr_hdr(app, attr->value, attr->len) < 0)
+                       goto queue;
+       }
+
+       len = be16_to_cpu(get_unaligned(&mrp_cb(app->pdu)->vah->lenflags));
+       pos = len % 3;
+
+       /* Events are packed into Vectors in the PDU, three to a byte. Add a
+        * byte to the end of the Vector if necessary.
+        */
+       if (!pos) {
+               if (skb_tailroom(app->pdu) < sizeof(u8))
+                       goto queue;
+               vaevents = (u8 *)__skb_put(app->pdu, sizeof(u8));
+       } else {
+               vaevents = (u8 *)(skb_tail_pointer(app->pdu) - sizeof(u8));
+       }
+
+       switch (pos) {
+       case 0:
+               *vaevents = vaevent * (__MRP_VECATTR_EVENT_MAX *
+                                      __MRP_VECATTR_EVENT_MAX);
+               break;
+       case 1:
+               *vaevents += vaevent * __MRP_VECATTR_EVENT_MAX;
+               break;
+       case 2:
+               *vaevents += vaevent;
+               break;
+       default:
+               WARN_ON(1);
+       }
+
+       /* Increment the length of the VectorAttribute in the PDU, as well as
+        * the value of the next attribute that would continue its Vector.
+        */
+       put_unaligned(cpu_to_be16(++len), &mrp_cb(app->pdu)->vah->lenflags);
+       mrp_attrvalue_inc(mrp_cb(app->pdu)->attrvalue, attr->len);
+
+       return 0;
+
+queue:
+       mrp_pdu_queue(app);
+       goto again;
+}
+
+static void mrp_attr_event(struct mrp_applicant *app,
+                          struct mrp_attr *attr, enum mrp_event event)
+{
+       enum mrp_applicant_state state;
+
+       state = mrp_applicant_state_table[attr->state][event];
+       if (state == MRP_APPLICANT_INVALID) {
+               WARN_ON(1);
+               return;
+       }
+
+       if (event == MRP_EVENT_TX) {
+               /* When appending the attribute fails, don't update its state
+                * in order to retry at the next TX event.
+                */
+
+               switch (mrp_tx_action_table[attr->state]) {
+               case MRP_TX_ACTION_NONE:
+               case MRP_TX_ACTION_S_JOIN_IN_OPTIONAL:
+               case MRP_TX_ACTION_S_IN_OPTIONAL:
+                       break;
+               case MRP_TX_ACTION_S_NEW:
+                       if (mrp_pdu_append_vecattr_event(
+                                   app, attr, MRP_VECATTR_EVENT_NEW) < 0)
+                               return;
+                       break;
+               case MRP_TX_ACTION_S_JOIN_IN:
+                       if (mrp_pdu_append_vecattr_event(
+                                   app, attr, MRP_VECATTR_EVENT_JOIN_IN) < 0)
+                               return;
+                       break;
+               case MRP_TX_ACTION_S_LV:
+                       if (mrp_pdu_append_vecattr_event(
+                                   app, attr, MRP_VECATTR_EVENT_LV) < 0)
+                               return;
+                       /* As a pure applicant, sending a leave message
+                        * implies that the attribute was unregistered and
+                        * can be destroyed.
+                        */
+                       mrp_attr_destroy(app, attr);
+                       return;
+               default:
+                       WARN_ON(1);
+               }
+       }
+
+       attr->state = state;
+}
+
+int mrp_request_join(const struct net_device *dev,
+                    const struct mrp_application *appl,
+                    const void *value, u8 len, u8 type)
+{
+       struct mrp_port *port = rtnl_dereference(dev->mrp_port);
+       struct mrp_applicant *app = rtnl_dereference(
+               port->applicants[appl->type]);
+       struct mrp_attr *attr;
+
+       if (sizeof(struct mrp_skb_cb) + len >
+           FIELD_SIZEOF(struct sk_buff, cb))
+               return -ENOMEM;
+
+       spin_lock_bh(&app->lock);
+       attr = mrp_attr_create(app, value, len, type);
+       if (!attr) {
+               spin_unlock_bh(&app->lock);
+               return -ENOMEM;
+       }
+       mrp_attr_event(app, attr, MRP_EVENT_JOIN);
+       spin_unlock_bh(&app->lock);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(mrp_request_join);
+
+void mrp_request_leave(const struct net_device *dev,
+                      const struct mrp_application *appl,
+                      const void *value, u8 len, u8 type)
+{
+       struct mrp_port *port = rtnl_dereference(dev->mrp_port);
+       struct mrp_applicant *app = rtnl_dereference(
+               port->applicants[appl->type]);
+       struct mrp_attr *attr;
+
+       if (sizeof(struct mrp_skb_cb) + len >
+           FIELD_SIZEOF(struct sk_buff, cb))
+               return;
+
+       spin_lock_bh(&app->lock);
+       attr = mrp_attr_lookup(app, value, len, type);
+       if (!attr) {
+               spin_unlock_bh(&app->lock);
+               return;
+       }
+       mrp_attr_event(app, attr, MRP_EVENT_LV);
+       spin_unlock_bh(&app->lock);
+}
+EXPORT_SYMBOL_GPL(mrp_request_leave);
+
+static void mrp_mad_event(struct mrp_applicant *app, enum mrp_event event)
+{
+       struct rb_node *node, *next;
+       struct mrp_attr *attr;
+
+       for (node = rb_first(&app->mad);
+            next = node ? rb_next(node) : NULL, node != NULL;
+            node = next) {
+               attr = rb_entry(node, struct mrp_attr, node);
+               mrp_attr_event(app, attr, event);
+       }
+}
+
+static void mrp_join_timer_arm(struct mrp_applicant *app)
+{
+       unsigned long delay;
+
+       delay = (u64)msecs_to_jiffies(mrp_join_time) * net_random() >> 32;
+       mod_timer(&app->join_timer, jiffies + delay);
+}
+
+static void mrp_join_timer(unsigned long data)
+{
+       struct mrp_applicant *app = (struct mrp_applicant *)data;
+
+       spin_lock(&app->lock);
+       mrp_mad_event(app, MRP_EVENT_TX);
+       mrp_pdu_queue(app);
+       spin_unlock(&app->lock);
+
+       mrp_queue_xmit(app);
+       mrp_join_timer_arm(app);
+}
+
+static int mrp_pdu_parse_end_mark(struct sk_buff *skb, int *offset)
+{
+       __be16 endmark;
+
+       if (skb_copy_bits(skb, *offset, &endmark, sizeof(endmark)) < 0)
+               return -1;
+       if (endmark == MRP_END_MARK) {
+               *offset += sizeof(endmark);
+               return -1;
+       }
+       return 0;
+}
+
+static void mrp_pdu_parse_vecattr_event(struct mrp_applicant *app,
+                                       struct sk_buff *skb,
+                                       enum mrp_vecattr_event vaevent)
+{
+       struct mrp_attr *attr;
+       enum mrp_event event;
+
+       attr = mrp_attr_lookup(app, mrp_cb(skb)->attrvalue,
+                              mrp_cb(skb)->mh->attrlen,
+                              mrp_cb(skb)->mh->attrtype);
+       if (attr == NULL)
+               return;
+
+       switch (vaevent) {
+       case MRP_VECATTR_EVENT_NEW:
+               event = MRP_EVENT_R_NEW;
+               break;
+       case MRP_VECATTR_EVENT_JOIN_IN:
+               event = MRP_EVENT_R_JOIN_IN;
+               break;
+       case MRP_VECATTR_EVENT_IN:
+               event = MRP_EVENT_R_IN;
+               break;
+       case MRP_VECATTR_EVENT_JOIN_MT:
+               event = MRP_EVENT_R_JOIN_MT;
+               break;
+       case MRP_VECATTR_EVENT_MT:
+               event = MRP_EVENT_R_MT;
+               break;
+       case MRP_VECATTR_EVENT_LV:
+               event = MRP_EVENT_R_LV;
+               break;
+       default:
+               return;
+       }
+
+       mrp_attr_event(app, attr, event);
+}
+
+static int mrp_pdu_parse_vecattr(struct mrp_applicant *app,
+                                struct sk_buff *skb, int *offset)
+{
+       struct mrp_vecattr_hdr _vah;
+       u16 valen;
+       u8 vaevents, vaevent;
+
+       mrp_cb(skb)->vah = skb_header_pointer(skb, *offset, sizeof(_vah),
+                                             &_vah);
+       if (!mrp_cb(skb)->vah)
+               return -1;
+       *offset += sizeof(_vah);
+
+       if (get_unaligned(&mrp_cb(skb)->vah->lenflags) &
+           MRP_VECATTR_HDR_FLAG_LA)
+               mrp_mad_event(app, MRP_EVENT_R_LA);
+       valen = be16_to_cpu(get_unaligned(&mrp_cb(skb)->vah->lenflags) &
+                           MRP_VECATTR_HDR_LEN_MASK);
+
+       /* The VectorAttribute structure in a PDU carries event information
+        * about one or more attributes having consecutive values. Only the
+        * value for the first attribute is contained in the structure. So
+        * we make a copy of that value, and then increment it each time we
+        * advance to the next event in its Vector.
+        */
+       if (sizeof(struct mrp_skb_cb) + mrp_cb(skb)->mh->attrlen >
+           FIELD_SIZEOF(struct sk_buff, cb))
+               return -1;
+       if (skb_copy_bits(skb, *offset, mrp_cb(skb)->attrvalue,
+                         mrp_cb(skb)->mh->attrlen) < 0)
+               return -1;
+       *offset += mrp_cb(skb)->mh->attrlen;
+
+       /* In a VectorAttribute, the Vector contains events which are packed
+        * three to a byte. We process one byte of the Vector at a time.
+        */
+       while (valen > 0) {
+               if (skb_copy_bits(skb, *offset, &vaevents,
+                                 sizeof(vaevents)) < 0)
+                       return -1;
+               *offset += sizeof(vaevents);
+
+               /* Extract and process the first event. */
+               vaevent = vaevents / (__MRP_VECATTR_EVENT_MAX *
+                                     __MRP_VECATTR_EVENT_MAX);
+               if (vaevent >= __MRP_VECATTR_EVENT_MAX) {
+                       /* The byte is malformed; stop processing. */
+                       return -1;
+               }
+               mrp_pdu_parse_vecattr_event(app, skb, vaevent);
+
+               /* If present, extract and process the second event. */
+               if (!--valen)
+                       break;
+               mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
+                                 mrp_cb(skb)->mh->attrlen);
+               vaevents %= (__MRP_VECATTR_EVENT_MAX *
+                            __MRP_VECATTR_EVENT_MAX);
+               vaevent = vaevents / __MRP_VECATTR_EVENT_MAX;
+               mrp_pdu_parse_vecattr_event(app, skb, vaevent);
+
+               /* If present, extract and process the third event. */
+               if (!--valen)
+                       break;
+               mrp_attrvalue_inc(mrp_cb(skb)->attrvalue,
+                                 mrp_cb(skb)->mh->attrlen);
+               vaevents %= __MRP_VECATTR_EVENT_MAX;
+               vaevent = vaevents;
+               mrp_pdu_parse_vecattr_event(app, skb, vaevent);
+       }
+       return 0;
+}
+
+static int mrp_pdu_parse_msg(struct mrp_applicant *app, struct sk_buff *skb,
+                            int *offset)
+{
+       struct mrp_msg_hdr _mh;
+
+       mrp_cb(skb)->mh = skb_header_pointer(skb, *offset, sizeof(_mh), &_mh);
+       if (!mrp_cb(skb)->mh)
+               return -1;
+       *offset += sizeof(_mh);
+
+       if (mrp_cb(skb)->mh->attrtype == 0 ||
+           mrp_cb(skb)->mh->attrtype > app->app->maxattr ||
+           mrp_cb(skb)->mh->attrlen == 0)
+               return -1;
+
+       while (skb->len > *offset) {
+               if (mrp_pdu_parse_end_mark(skb, offset) < 0)
+                       break;
+               if (mrp_pdu_parse_vecattr(app, skb, offset) < 0)
+                       return -1;
+       }
+       return 0;
+}
+
+int mrp_rcv(struct sk_buff *skb, struct net_device *dev,
+           struct packet_type *pt, struct net_device *orig_dev)
+{
+       struct mrp_application *appl = container_of(pt, struct mrp_application,
+                                                   pkttype);
+       struct mrp_port *port;
+       struct mrp_applicant *app;
+       struct mrp_pdu_hdr _ph;
+       const struct mrp_pdu_hdr *ph;
+       int offset = skb_network_offset(skb);
+
+       /* If the interface is in promiscuous mode, drop the packet if
+        * it was unicast to another host.
+        */
+       if (unlikely(skb->pkt_type == PACKET_OTHERHOST))
+               goto out;
+       skb = skb_share_check(skb, GFP_ATOMIC);
+       if (unlikely(!skb))
+               goto out;
+       port = rcu_dereference(dev->mrp_port);
+       if (unlikely(!port))
+               goto out;
+       app = rcu_dereference(port->applicants[appl->type]);
+       if (unlikely(!app))
+               goto out;
+
+       ph = skb_header_pointer(skb, offset, sizeof(_ph), &_ph);
+       if (!ph)
+               goto out;
+       offset += sizeof(_ph);
+
+       if (ph->version != app->app->version)
+               goto out;
+
+       spin_lock(&app->lock);
+       while (skb->len > offset) {
+               if (mrp_pdu_parse_end_mark(skb, &offset) < 0)
+                       break;
+               if (mrp_pdu_parse_msg(app, skb, &offset) < 0)
+                       break;
+       }
+       spin_unlock(&app->lock);
+out:
+       kfree_skb(skb);
+       return 0;
+}
+
+static int mrp_init_port(struct net_device *dev)
+{
+       struct mrp_port *port;
+
+       port = kzalloc(sizeof(*port), GFP_KERNEL);
+       if (!port)
+               return -ENOMEM;
+       rcu_assign_pointer(dev->mrp_port, port);
+       return 0;
+}
+
+static void mrp_release_port(struct net_device *dev)
+{
+       struct mrp_port *port = rtnl_dereference(dev->mrp_port);
+       unsigned int i;
+
+       for (i = 0; i <= MRP_APPLICATION_MAX; i++) {
+               if (rtnl_dereference(port->applicants[i]))
+                       return;
+       }
+       RCU_INIT_POINTER(dev->mrp_port, NULL);
+       kfree_rcu(port, rcu);
+}
+
+int mrp_init_applicant(struct net_device *dev, struct mrp_application *appl)
+{
+       struct mrp_applicant *app;
+       int err;
+
+       ASSERT_RTNL();
+
+       if (!rtnl_dereference(dev->mrp_port)) {
+               err = mrp_init_port(dev);
+               if (err < 0)
+                       goto err1;
+       }
+
+       err = -ENOMEM;
+       app = kzalloc(sizeof(*app), GFP_KERNEL);
+       if (!app)
+               goto err2;
+
+       err = dev_mc_add(dev, appl->group_address);
+       if (err < 0)
+               goto err3;
+
+       app->dev = dev;
+       app->app = appl;
+       app->mad = RB_ROOT;
+       spin_lock_init(&app->lock);
+       skb_queue_head_init(&app->queue);
+       rcu_assign_pointer(dev->mrp_port->applicants[appl->type], app);
+       setup_timer(&app->join_timer, mrp_join_timer, (unsigned long)app);
+       mrp_join_timer_arm(app);
+       return 0;
+
+err3:
+       kfree(app);
+err2:
+       mrp_release_port(dev);
+err1:
+       return err;
+}
+EXPORT_SYMBOL_GPL(mrp_init_applicant);
+
+void mrp_uninit_applicant(struct net_device *dev, struct mrp_application *appl)
+{
+       struct mrp_port *port = rtnl_dereference(dev->mrp_port);
+       struct mrp_applicant *app = rtnl_dereference(
+               port->applicants[appl->type]);
+
+       ASSERT_RTNL();
+
+       RCU_INIT_POINTER(port->applicants[appl->type], NULL);
+
+       /* Delete timer and generate a final TX event to flush out
+        * all pending messages before the applicant is gone.
+        */
+       del_timer_sync(&app->join_timer);
+       mrp_mad_event(app, MRP_EVENT_TX);
+       mrp_pdu_queue(app);
+       mrp_queue_xmit(app);
+
+       dev_mc_del(dev, appl->group_address);
+       kfree_rcu(app, rcu);
+       mrp_release_port(dev);
+}
+EXPORT_SYMBOL_GPL(mrp_uninit_applicant);
+
+int mrp_register_application(struct mrp_application *appl)
+{
+       appl->pkttype.func = mrp_rcv;
+       dev_add_pack(&appl->pkttype);
+       return 0;
+}
+EXPORT_SYMBOL_GPL(mrp_register_application);
+
+void mrp_unregister_application(struct mrp_application *appl)
+{
+       dev_remove_pack(&appl->pkttype);
+}
+EXPORT_SYMBOL_GPL(mrp_unregister_application);