net: Add GARP applicant-only participant
Add an implementation of the GARP (Generic Attribute Registration Protocol)
applicant-only participant. This will be used by the following patch to
add GVRP support to the VLAN code.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/802/Kconfig b/net/802/Kconfig
index 01cb094..be33d27 100644
--- a/net/802/Kconfig
+++ b/net/802/Kconfig
@@ -1,3 +1,7 @@
config STP
tristate
select LLC
+
+config GARP
+ tristate
+ select STP
diff --git a/net/802/Makefile b/net/802/Makefile
index c441d89..7893d67 100644
--- a/net/802/Makefile
+++ b/net/802/Makefile
@@ -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
diff --git a/net/802/garp.c b/net/802/garp.c
new file mode 100644
index 0000000..3b78f7b
--- /dev/null
+++ b/net/802/garp.c
@@ -0,0 +1,633 @@
+/*
+ * IEEE 802.1D Generic Attribute Registration Protocol (GARP)
+ *
+ * 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/llc.h>
+#include <net/llc.h>
+#include <net/llc_pdu.h>
+#include <net/garp.h>
+#include <asm/unaligned.h>
+
+static unsigned int garp_join_time __read_mostly = 200;
+module_param(garp_join_time, uint, 0644);
+MODULE_PARM_DESC(garp_join_time, "Join time in ms (default 200ms)");
+MODULE_LICENSE("GPL");
+
+static const struct garp_state_trans {
+ u8 state;
+ u8 action;
+} garp_applicant_state_table[GARP_APPLICANT_MAX + 1][GARP_EVENT_MAX + 1] = {
+ [GARP_APPLICANT_VA] = {
+ [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_AA,
+ .action = GARP_ACTION_S_JOIN_IN },
+ [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_AA },
+ [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VA },
+ [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VA },
+ [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VA },
+ [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
+ [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_LA },
+ },
+ [GARP_APPLICANT_AA] = {
+ [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_QA,
+ .action = GARP_ACTION_S_JOIN_IN },
+ [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QA },
+ [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VA },
+ [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VA },
+ [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VA },
+ [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
+ [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_LA },
+ },
+ [GARP_APPLICANT_QA] = {
+ [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
+ [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QA },
+ [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VA },
+ [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VA },
+ [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
+ [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_LA },
+ },
+ [GARP_APPLICANT_LA] = {
+ [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_VO,
+ .action = GARP_ACTION_S_LEAVE_EMPTY },
+ [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_LA },
+ [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
+ [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_LA },
+ [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_LA },
+ [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
+ [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_VA },
+ [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
+ },
+ [GARP_APPLICANT_VP] = {
+ [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_AA,
+ .action = GARP_ACTION_S_JOIN_IN },
+ [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_AP },
+ [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
+ [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_VO },
+ },
+ [GARP_APPLICANT_AP] = {
+ [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_QA,
+ .action = GARP_ACTION_S_JOIN_IN },
+ [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QP },
+ [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
+ [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_AO },
+ },
+ [GARP_APPLICANT_QP] = {
+ [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
+ [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QP },
+ [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_INVALID },
+ [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_QO },
+ },
+ [GARP_APPLICANT_VO] = {
+ [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
+ [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_AO },
+ [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
+ [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VO },
+ [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VO },
+ [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
+ [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_VP },
+ [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
+ },
+ [GARP_APPLICANT_AO] = {
+ [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
+ [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QO },
+ [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
+ [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VO },
+ [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VO },
+ [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
+ [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_AP },
+ [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
+ },
+ [GARP_APPLICANT_QO] = {
+ [GARP_EVENT_TRANSMIT_PDU] = { .state = GARP_APPLICANT_INVALID },
+ [GARP_EVENT_R_JOIN_IN] = { .state = GARP_APPLICANT_QO },
+ [GARP_EVENT_R_JOIN_EMPTY] = { .state = GARP_APPLICANT_VO },
+ [GARP_EVENT_R_EMPTY] = { .state = GARP_APPLICANT_VO },
+ [GARP_EVENT_R_LEAVE_IN] = { .state = GARP_APPLICANT_VO },
+ [GARP_EVENT_R_LEAVE_EMPTY] = { .state = GARP_APPLICANT_VO },
+ [GARP_EVENT_REQ_JOIN] = { .state = GARP_APPLICANT_QP },
+ [GARP_EVENT_REQ_LEAVE] = { .state = GARP_APPLICANT_INVALID },
+ },
+};
+
+static int garp_attr_cmp(const struct garp_attr *attr,
+ const void *data, u8 len, u8 type)
+{
+ if (attr->type != type)
+ return attr->type - type;
+ if (attr->dlen != len)
+ return attr->dlen - len;
+ return memcmp(attr->data, data, len);
+}
+
+static struct garp_attr *garp_attr_lookup(const struct garp_applicant *app,
+ const void *data, u8 len, u8 type)
+{
+ struct rb_node *parent = app->gid.rb_node;
+ struct garp_attr *attr;
+ int d;
+
+ while (parent) {
+ attr = rb_entry(parent, struct garp_attr, node);
+ d = garp_attr_cmp(attr, data, len, type);
+ if (d < 0)
+ parent = parent->rb_left;
+ else if (d > 0)
+ parent = parent->rb_right;
+ else
+ return attr;
+ }
+ return NULL;
+}
+
+static void garp_attr_insert(struct garp_applicant *app, struct garp_attr *new)
+{
+ struct rb_node *parent = NULL, **p = &app->gid.rb_node;
+ struct garp_attr *attr;
+ int d;
+
+ while (*p) {
+ parent = *p;
+ attr = rb_entry(parent, struct garp_attr, node);
+ d = garp_attr_cmp(attr, new->data, new->dlen, new->type);
+ if (d < 0)
+ p = &parent->rb_left;
+ else if (d > 0)
+ p = &parent->rb_right;
+ }
+ rb_link_node(&new->node, parent, p);
+ rb_insert_color(&new->node, &app->gid);
+}
+
+static struct garp_attr *garp_attr_create(struct garp_applicant *app,
+ const void *data, u8 len, u8 type)
+{
+ struct garp_attr *attr;
+
+ attr = kmalloc(sizeof(*attr) + len, GFP_ATOMIC);
+ if (!attr)
+ return attr;
+ attr->state = GARP_APPLICANT_VO;
+ attr->type = type;
+ attr->dlen = len;
+ memcpy(attr->data, data, len);
+ garp_attr_insert(app, attr);
+ return attr;
+}
+
+static void garp_attr_destroy(struct garp_applicant *app, struct garp_attr *attr)
+{
+ rb_erase(&attr->node, &app->gid);
+ kfree(attr);
+}
+
+static int garp_pdu_init(struct garp_applicant *app)
+{
+ struct sk_buff *skb;
+ struct garp_pdu_hdr *gp;
+
+#define LLC_RESERVE sizeof(struct llc_pdu_un)
+ skb = alloc_skb(app->dev->mtu + LL_RESERVED_SPACE(app->dev),
+ GFP_ATOMIC);
+ if (!skb)
+ return -ENOMEM;
+
+ skb->dev = app->dev;
+ skb->protocol = htons(ETH_P_802_2);
+ skb_reserve(skb, LL_RESERVED_SPACE(app->dev) + LLC_RESERVE);
+
+ gp = (struct garp_pdu_hdr *)__skb_put(skb, sizeof(*gp));
+ put_unaligned(htons(GARP_PROTOCOL_ID), &gp->protocol);
+
+ app->pdu = skb;
+ return 0;
+}
+
+static int garp_pdu_append_end_mark(struct garp_applicant *app)
+{
+ if (skb_tailroom(app->pdu) < sizeof(u8))
+ return -1;
+ *(u8 *)__skb_put(app->pdu, sizeof(u8)) = GARP_END_MARK;
+ return 0;
+}
+
+static void garp_pdu_queue(struct garp_applicant *app)
+{
+ if (!app->pdu)
+ return;
+
+ garp_pdu_append_end_mark(app);
+ garp_pdu_append_end_mark(app);
+
+ llc_pdu_header_init(app->pdu, LLC_PDU_TYPE_U, LLC_SAP_BSPAN,
+ LLC_SAP_BSPAN, LLC_PDU_CMD);
+ llc_pdu_init_as_ui_cmd(app->pdu);
+ llc_mac_hdr_init(app->pdu, app->dev->dev_addr,
+ app->app->proto.group_address);
+
+ skb_queue_tail(&app->queue, app->pdu);
+ app->pdu = NULL;
+}
+
+static void garp_queue_xmit(struct garp_applicant *app)
+{
+ struct sk_buff *skb;
+
+ while ((skb = skb_dequeue(&app->queue)))
+ dev_queue_xmit(skb);
+}
+
+static int garp_pdu_append_msg(struct garp_applicant *app, u8 attrtype)
+{
+ struct garp_msg_hdr *gm;
+
+ if (skb_tailroom(app->pdu) < sizeof(*gm))
+ return -1;
+ gm = (struct garp_msg_hdr *)__skb_put(app->pdu, sizeof(*gm));
+ gm->attrtype = attrtype;
+ garp_cb(app->pdu)->cur_type = attrtype;
+ return 0;
+}
+
+static int garp_pdu_append_attr(struct garp_applicant *app,
+ const struct garp_attr *attr,
+ enum garp_attr_event event)
+{
+ struct garp_attr_hdr *ga;
+ unsigned int len;
+ int err;
+again:
+ if (!app->pdu) {
+ err = garp_pdu_init(app);
+ if (err < 0)
+ return err;
+ }
+
+ if (garp_cb(app->pdu)->cur_type != attr->type) {
+ if (garp_cb(app->pdu)->cur_type &&
+ garp_pdu_append_end_mark(app) < 0)
+ goto queue;
+ if (garp_pdu_append_msg(app, attr->type) < 0)
+ goto queue;
+ }
+
+ len = sizeof(*ga) + attr->dlen;
+ if (skb_tailroom(app->pdu) < len)
+ goto queue;
+ ga = (struct garp_attr_hdr *)__skb_put(app->pdu, len);
+ ga->len = len;
+ ga->event = event;
+ memcpy(ga->data, attr->data, attr->dlen);
+ return 0;
+
+queue:
+ garp_pdu_queue(app);
+ goto again;
+}
+
+static void garp_attr_event(struct garp_applicant *app,
+ struct garp_attr *attr, enum garp_event event)
+{
+ enum garp_applicant_state state;
+
+ state = garp_applicant_state_table[attr->state][event].state;
+ if (state == GARP_APPLICANT_INVALID)
+ return;
+
+ switch (garp_applicant_state_table[attr->state][event].action) {
+ case GARP_ACTION_NONE:
+ break;
+ case GARP_ACTION_S_JOIN_IN:
+ garp_pdu_append_attr(app, attr, GARP_JOIN_IN);
+ break;
+ case GARP_ACTION_S_LEAVE_EMPTY:
+ garp_pdu_append_attr(app, attr, GARP_LEAVE_EMPTY);
+ /* As a pure applicant, sending a leave message implies that
+ * the attribute was unregistered and can be destroyed. */
+ garp_attr_destroy(app, attr);
+ return;
+ default:
+ WARN_ON(1);
+ }
+
+ attr->state = state;
+}
+
+int garp_request_join(const struct net_device *dev,
+ const struct garp_application *appl,
+ const void *data, u8 len, u8 type)
+{
+ struct garp_port *port = dev->garp_port;
+ struct garp_applicant *app = port->applicants[appl->type];
+ struct garp_attr *attr;
+
+ spin_lock_bh(&app->lock);
+ attr = garp_attr_create(app, data, len, type);
+ if (!attr) {
+ spin_unlock_bh(&app->lock);
+ return -ENOMEM;
+ }
+ garp_attr_event(app, attr, GARP_EVENT_REQ_JOIN);
+ spin_unlock_bh(&app->lock);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(garp_request_join);
+
+void garp_request_leave(const struct net_device *dev,
+ const struct garp_application *appl,
+ const void *data, u8 len, u8 type)
+{
+ struct garp_port *port = dev->garp_port;
+ struct garp_applicant *app = port->applicants[appl->type];
+ struct garp_attr *attr;
+
+ spin_lock_bh(&app->lock);
+ attr = garp_attr_lookup(app, data, len, type);
+ if (!attr) {
+ spin_unlock_bh(&app->lock);
+ return;
+ }
+ garp_attr_event(app, attr, GARP_EVENT_REQ_LEAVE);
+ spin_unlock_bh(&app->lock);
+}
+EXPORT_SYMBOL_GPL(garp_request_leave);
+
+static void garp_gid_event(struct garp_applicant *app, enum garp_event event)
+{
+ struct rb_node *node, *next;
+ struct garp_attr *attr;
+
+ for (node = rb_first(&app->gid);
+ next = node ? rb_next(node) : NULL, node != NULL;
+ node = next) {
+ attr = rb_entry(node, struct garp_attr, node);
+ garp_attr_event(app, attr, event);
+ }
+}
+
+static void garp_join_timer_arm(struct garp_applicant *app)
+{
+ unsigned long delay;
+
+ delay = (u64)msecs_to_jiffies(garp_join_time) * net_random() >> 32;
+ mod_timer(&app->join_timer, jiffies + delay);
+}
+
+static void garp_join_timer(unsigned long data)
+{
+ struct garp_applicant *app = (struct garp_applicant *)data;
+
+ spin_lock(&app->lock);
+ garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU);
+ garp_pdu_queue(app);
+ spin_unlock(&app->lock);
+
+ garp_queue_xmit(app);
+ garp_join_timer_arm(app);
+}
+
+static int garp_pdu_parse_end_mark(struct sk_buff *skb)
+{
+ if (!pskb_may_pull(skb, sizeof(u8)))
+ return -1;
+ if (*skb->data == GARP_END_MARK) {
+ skb_pull(skb, sizeof(u8));
+ return -1;
+ }
+ return 0;
+}
+
+static int garp_pdu_parse_attr(struct garp_applicant *app, struct sk_buff *skb,
+ u8 attrtype)
+{
+ const struct garp_attr_hdr *ga;
+ struct garp_attr *attr;
+ enum garp_event event;
+ unsigned int dlen;
+
+ if (!pskb_may_pull(skb, sizeof(*ga)))
+ return -1;
+ ga = (struct garp_attr_hdr *)skb->data;
+ if (ga->len < sizeof(*ga))
+ return -1;
+
+ if (!pskb_may_pull(skb, ga->len))
+ return -1;
+ skb_pull(skb, ga->len);
+ dlen = sizeof(*ga) - ga->len;
+
+ if (attrtype > app->app->maxattr)
+ return 0;
+
+ switch (ga->event) {
+ case GARP_LEAVE_ALL:
+ if (dlen != 0)
+ return -1;
+ garp_gid_event(app, GARP_EVENT_R_LEAVE_EMPTY);
+ return 0;
+ case GARP_JOIN_EMPTY:
+ event = GARP_EVENT_R_JOIN_EMPTY;
+ break;
+ case GARP_JOIN_IN:
+ event = GARP_EVENT_R_JOIN_IN;
+ break;
+ case GARP_LEAVE_EMPTY:
+ event = GARP_EVENT_R_LEAVE_EMPTY;
+ break;
+ case GARP_EMPTY:
+ event = GARP_EVENT_R_EMPTY;
+ break;
+ default:
+ return 0;
+ }
+
+ if (dlen == 0)
+ return -1;
+ attr = garp_attr_lookup(app, ga->data, dlen, attrtype);
+ if (attr == NULL)
+ return 0;
+ garp_attr_event(app, attr, event);
+ return 0;
+}
+
+static int garp_pdu_parse_msg(struct garp_applicant *app, struct sk_buff *skb)
+{
+ const struct garp_msg_hdr *gm;
+
+ if (!pskb_may_pull(skb, sizeof(*gm)))
+ return -1;
+ gm = (struct garp_msg_hdr *)skb->data;
+ if (gm->attrtype == 0)
+ return -1;
+ skb_pull(skb, sizeof(*gm));
+
+ while (skb->len > 0) {
+ if (garp_pdu_parse_attr(app, skb, gm->attrtype) < 0)
+ return -1;
+ if (garp_pdu_parse_end_mark(skb) < 0)
+ break;
+ }
+ return 0;
+}
+
+static void garp_pdu_rcv(const struct stp_proto *proto, struct sk_buff *skb,
+ struct net_device *dev)
+{
+ struct garp_application *appl = proto->data;
+ struct garp_port *port;
+ struct garp_applicant *app;
+ const struct garp_pdu_hdr *gp;
+
+ port = rcu_dereference(dev->garp_port);
+ if (!port)
+ goto err;
+ app = rcu_dereference(port->applicants[appl->type]);
+ if (!app)
+ goto err;
+
+ if (!pskb_may_pull(skb, sizeof(*gp)))
+ goto err;
+ gp = (struct garp_pdu_hdr *)skb->data;
+ if (get_unaligned(&gp->protocol) != htons(GARP_PROTOCOL_ID))
+ goto err;
+ skb_pull(skb, sizeof(*gp));
+
+ spin_lock(&app->lock);
+ while (skb->len > 0) {
+ if (garp_pdu_parse_msg(app, skb) < 0)
+ break;
+ if (garp_pdu_parse_end_mark(skb) < 0)
+ break;
+ }
+ spin_unlock(&app->lock);
+err:
+ kfree_skb(skb);
+}
+
+static int garp_init_port(struct net_device *dev)
+{
+ struct garp_port *port;
+
+ port = kzalloc(sizeof(*port), GFP_KERNEL);
+ if (!port)
+ return -ENOMEM;
+ rcu_assign_pointer(dev->garp_port, port);
+ return 0;
+}
+
+static void garp_release_port(struct net_device *dev)
+{
+ struct garp_port *port = dev->garp_port;
+ unsigned int i;
+
+ for (i = 0; i <= GARP_APPLICATION_MAX; i++) {
+ if (port->applicants[i])
+ return;
+ }
+ rcu_assign_pointer(dev->garp_port, NULL);
+ synchronize_rcu();
+ kfree(port);
+}
+
+int garp_init_applicant(struct net_device *dev, struct garp_application *appl)
+{
+ struct garp_applicant *app;
+ int err;
+
+ ASSERT_RTNL();
+
+ if (!dev->garp_port) {
+ err = garp_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->proto.group_address, ETH_ALEN, 0);
+ if (err < 0)
+ goto err3;
+
+ app->dev = dev;
+ app->app = appl;
+ app->gid = RB_ROOT;
+ spin_lock_init(&app->lock);
+ skb_queue_head_init(&app->queue);
+ rcu_assign_pointer(dev->garp_port->applicants[appl->type], app);
+ setup_timer(&app->join_timer, garp_join_timer, (unsigned long)app);
+ garp_join_timer_arm(app);
+ return 0;
+
+err3:
+ kfree(app);
+err2:
+ garp_release_port(dev);
+err1:
+ return err;
+}
+EXPORT_SYMBOL_GPL(garp_init_applicant);
+
+void garp_uninit_applicant(struct net_device *dev, struct garp_application *appl)
+{
+ struct garp_port *port = dev->garp_port;
+ struct garp_applicant *app = port->applicants[appl->type];
+
+ ASSERT_RTNL();
+
+ rcu_assign_pointer(port->applicants[appl->type], NULL);
+ synchronize_rcu();
+
+ /* Delete timer and generate a final TRANSMIT_PDU event to flush out
+ * all pending messages before the applicant is gone. */
+ del_timer_sync(&app->join_timer);
+ garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU);
+ garp_pdu_queue(app);
+ garp_queue_xmit(app);
+
+ dev_mc_delete(dev, appl->proto.group_address, ETH_ALEN, 0);
+ kfree(app);
+ garp_release_port(dev);
+}
+EXPORT_SYMBOL_GPL(garp_uninit_applicant);
+
+int garp_register_application(struct garp_application *appl)
+{
+ appl->proto.rcv = garp_pdu_rcv;
+ appl->proto.data = appl;
+ return stp_proto_register(&appl->proto);
+}
+EXPORT_SYMBOL_GPL(garp_register_application);
+
+void garp_unregister_application(struct garp_application *appl)
+{
+ stp_proto_unregister(&appl->proto);
+}
+EXPORT_SYMBOL_GPL(garp_unregister_application);