team: add loadbalance mode

This patch introduces new team mode. It's TX port is selected by
user-set BPF hash function.

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 200 insertions, 0 deletions

diff --git a/drivers/net/team/Kconfig b/drivers/net/team/Kconfig
index 248a144033ca..89024d5fc33a 100644
--- a/drivers/net/team/Kconfig
+++ b/drivers/net/team/Kconfig
@@ -40,4 +40,15 @@ config NET_TEAM_MODE_ACTIVEBACKUP
           To compile this team mode as a module, choose M here: the module
           will be called team_mode_activebackup.
 
+config NET_TEAM_MODE_LOADBALANCE
+        tristate "Load-balance mode support"
+        depends on NET_TEAM
+        ---help---
+          This mode provides load balancing functionality. Tx port selection
+          is done using BPF function set up from userspace (bpf_hash_func
+          option)
+
+          To compile this team mode as a module, choose M here: the module
+          will be called team_mode_loadbalance.
+
 endif # NET_TEAM
diff --git a/drivers/net/team/Makefile b/drivers/net/team/Makefile
index 85f2028a87af..fb9f4c1c51ff 100644
--- a/drivers/net/team/Makefile
+++ b/drivers/net/team/Makefile
@@ -5,3 +5,4 @@
 obj-$(CONFIG_NET_TEAM) += team.o
 obj-$(CONFIG_NET_TEAM_MODE_ROUNDROBIN) += team_mode_roundrobin.o
 obj-$(CONFIG_NET_TEAM_MODE_ACTIVEBACKUP) += team_mode_activebackup.o
+obj-$(CONFIG_NET_TEAM_MODE_LOADBALANCE) += team_mode_loadbalance.o
diff --git a/drivers/net/team/team_mode_loadbalance.c b/drivers/net/team/team_mode_loadbalance.c
new file mode 100644
index 000000000000..ed20f395be6f
--- /dev/null
+++ b/drivers/net/team/team_mode_loadbalance.c
@@ -0,0 +1,188 @@
+/*
+ * drivers/net/team/team_mode_loadbalance.c - Load-balancing mode for team
+ * Copyright (c) 2012 Jiri Pirko <jpirko@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/errno.h>
+#include <linux/netdevice.h>
+#include <linux/filter.h>
+#include <linux/if_team.h>
+
+struct lb_priv {
+        struct sk_filter __rcu *fp;
+        struct sock_fprog *orig_fprog;
+};
+
+static struct lb_priv *lb_priv(struct team *team)
+{
+        return (struct lb_priv *) &team->mode_priv;
+}
+
+static bool lb_transmit(struct team *team, struct sk_buff *skb)
+{
+        struct sk_filter *fp;
+        struct team_port *port;
+        unsigned int hash;
+        int port_index;
+
+        fp = rcu_dereference(lb_priv(team)->fp);
+        if (unlikely(!fp))
+                goto drop;
+        hash = SK_RUN_FILTER(fp, skb);
+        port_index = hash % team->port_count;
+        port = team_get_port_by_index_rcu(team, port_index);
+        if (unlikely(!port))
+                goto drop;
+        skb->dev = port->dev;
+        if (dev_queue_xmit(skb))
+                return false;
+        return true;
+
+drop:
+        dev_kfree_skb_any(skb);
+        return false;
+}
+
+static int lb_bpf_func_get(struct team *team, void *arg)
+{
+        struct team_option_binary *tbinary = team_optarg_tbinary(arg);
+
+        memset(tbinary, 0, sizeof(*tbinary));
+        if (!lb_priv(team)->orig_fprog)
+                return 0;
+
+        tbinary->data_len = lb_priv(team)->orig_fprog->len *
+                            sizeof(struct sock_filter);
+        tbinary->data = lb_priv(team)->orig_fprog->filter;
+        return 0;
+}
+
+static int __fprog_create(struct sock_fprog **pfprog, u32 data_len,
+                          void *data)
+{
+        struct sock_fprog *fprog;
+        struct sock_filter *filter = (struct sock_filter *) data;
+
+        if (data_len % sizeof(struct sock_filter))
+                return -EINVAL;
+        fprog = kmalloc(sizeof(struct sock_fprog), GFP_KERNEL);
+        if (!fprog)
+                return -ENOMEM;
+        fprog->filter = kmemdup(filter, data_len, GFP_KERNEL);
+        if (!fprog->filter) {
+                kfree(fprog);
+                return -ENOMEM;
+        }
+        fprog->len = data_len / sizeof(struct sock_filter);
+        *pfprog = fprog;
+        return 0;
+}
+
+static void __fprog_destroy(struct sock_fprog *fprog)
+{
+        kfree(fprog->filter);
+        kfree(fprog);
+}
+
+static int lb_bpf_func_set(struct team *team, void *arg)
+{
+        struct team_option_binary *tbinary = team_optarg_tbinary(arg);
+        struct sk_filter *fp = NULL;
+        struct sock_fprog *fprog = NULL;
+        int err;
+
+        if (tbinary->data_len) {
+                err = __fprog_create(&fprog, tbinary->data_len,
+                                     tbinary->data);
+                if (err)
+                        return err;
+                err = sk_unattached_filter_create(&fp, fprog);
+                if (err) {
+                        __fprog_destroy(fprog);
+                        return err;
+                }
+        }
+
+        if (lb_priv(team)->orig_fprog) {
+                /* Clear old filter data */
+                __fprog_destroy(lb_priv(team)->orig_fprog);
+                sk_unattached_filter_destroy(lb_priv(team)->fp);
+        }
+
+        rcu_assign_pointer(lb_priv(team)->fp, fp);
+        lb_priv(team)->orig_fprog = fprog;
+        return 0;
+}
+
+static const struct team_option lb_options[] = {
+        {
+                .name = "bpf_hash_func",
+                .type = TEAM_OPTION_TYPE_BINARY,
+                .getter = lb_bpf_func_get,
+                .setter = lb_bpf_func_set,
+        },
+};
+
+int lb_init(struct team *team)
+{
+        return team_options_register(team, lb_options,
+                                     ARRAY_SIZE(lb_options));
+}
+
+void lb_exit(struct team *team)
+{
+        team_options_unregister(team, lb_options,
+                                ARRAY_SIZE(lb_options));
+}
+
+static int lb_port_enter(struct team *team, struct team_port *port)
+{
+        return team_port_set_team_mac(port);
+}
+
+static void lb_port_change_mac(struct team *team, struct team_port *port)
+{
+        team_port_set_team_mac(port);
+}
+
+static const struct team_mode_ops lb_mode_ops = {
+        .init                   = lb_init,
+        .exit                   = lb_exit,
+        .transmit               = lb_transmit,
+        .port_enter             = lb_port_enter,
+        .port_change_mac        = lb_port_change_mac,
+};
+
+static struct team_mode lb_mode = {
+        .kind           = "loadbalance",
+        .owner          = THIS_MODULE,
+        .priv_size      = sizeof(struct lb_priv),
+        .ops            = &lb_mode_ops,
+};
+
+static int __init lb_init_module(void)
+{
+        return team_mode_register(&lb_mode);
+}
+
+static void __exit lb_cleanup_module(void)
+{
+        team_mode_unregister(&lb_mode);
+}
+
+module_init(lb_init_module);
+module_exit(lb_cleanup_module);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Jiri Pirko <jpirko@redhat.com>");
+MODULE_DESCRIPTION("Load-balancing mode for team");
+MODULE_ALIAS("team-mode-loadbalance");