From 11dc1f36a6701b502ecb695f308aae46ede8bac6 Mon Sep 17 00:00:00 2001 From: Stephen Hemminger Date: Thu, 25 May 2006 16:00:12 -0700 Subject: [PATCH] [BRIDGE]: netlink interface for link management Add basic netlink support to the Ethernet bridge. Including: * dump interfaces in bridges * monitor link status changes * change state of bridge port For some demo programs see: http://developer.osdl.org/shemminger/prototypes/brnl.tar.gz These are to allow building a daemon that does alternative implementations of Spanning Tree Protocol. Signed-off-by: Stephen Hemminger Signed-off-by: David S. Miller --- net/bridge/Makefile | 2 +- net/bridge/br.c | 2 + net/bridge/br_netlink.c | 199 ++++++++++++++++++++++++++++++++++++++++ net/bridge/br_notify.c | 2 + net/bridge/br_private.h | 7 +- net/bridge/br_stp_if.c | 4 + 6 files changed, 214 insertions(+), 2 deletions(-) create mode 100644 net/bridge/br_netlink.c diff --git a/net/bridge/Makefile b/net/bridge/Makefile index 59556e40e143..f444c12cde5a 100644 --- a/net/bridge/Makefile +++ b/net/bridge/Makefile @@ -6,7 +6,7 @@ obj-$(CONFIG_BRIDGE) += bridge.o bridge-y := br.o br_device.o br_fdb.o br_forward.o br_if.o br_input.o \ br_ioctl.o br_notify.o br_stp.o br_stp_bpdu.o \ - br_stp_if.o br_stp_timer.o + br_stp_if.o br_stp_timer.o br_netlink.o bridge-$(CONFIG_SYSFS) += br_sysfs_if.o br_sysfs_br.o diff --git a/net/bridge/br.c b/net/bridge/br.c index 558d27204f60..654401ceb2db 100644 --- a/net/bridge/br.c +++ b/net/bridge/br.c @@ -48,6 +48,7 @@ static int __init br_init(void) if (err) goto err_out2; + br_netlink_init(); brioctl_set(br_ioctl_deviceless_stub); br_handle_frame_hook = br_handle_frame; @@ -67,6 +68,7 @@ static void __exit br_deinit(void) { rcu_assign_pointer(br_stp_sap->rcv_func, NULL); + br_netlink_fini(); br_netfilter_fini(); unregister_netdevice_notifier(&br_device_notifier); brioctl_set(NULL); diff --git a/net/bridge/br_netlink.c b/net/bridge/br_netlink.c new file mode 100644 index 000000000000..881d7d1a732a --- /dev/null +++ b/net/bridge/br_netlink.c @@ -0,0 +1,199 @@ +/* + * Bridge netlink control interface + * + * Authors: + * Stephen Hemminger + * + * 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 +#include +#include "br_private.h" + +/* + * Create one netlink message for one interface + * Contains port and master info as well as carrier and bridge state. + */ +static int br_fill_ifinfo(struct sk_buff *skb, const struct net_bridge_port *port, + u32 pid, u32 seq, int event, unsigned int flags) +{ + const struct net_bridge *br = port->br; + const struct net_device *dev = port->dev; + struct ifinfomsg *r; + struct nlmsghdr *nlh; + unsigned char *b = skb->tail; + u32 mtu = dev->mtu; + u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN; + u8 portstate = port->state; + + pr_debug("br_fill_info event %d port %s master %s\n", + event, dev->name, br->dev->name); + + nlh = NLMSG_NEW(skb, pid, seq, event, sizeof(*r), flags); + r = NLMSG_DATA(nlh); + r->ifi_family = AF_BRIDGE; + r->__ifi_pad = 0; + r->ifi_type = dev->type; + r->ifi_index = dev->ifindex; + r->ifi_flags = dev_get_flags(dev); + r->ifi_change = 0; + + RTA_PUT(skb, IFLA_IFNAME, strlen(dev->name)+1, dev->name); + + RTA_PUT(skb, IFLA_MASTER, sizeof(int), &br->dev->ifindex); + + if (dev->addr_len) + RTA_PUT(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr); + + RTA_PUT(skb, IFLA_MTU, sizeof(mtu), &mtu); + if (dev->ifindex != dev->iflink) + RTA_PUT(skb, IFLA_LINK, sizeof(int), &dev->iflink); + + + RTA_PUT(skb, IFLA_OPERSTATE, sizeof(operstate), &operstate); + + if (event == RTM_NEWLINK) + RTA_PUT(skb, IFLA_PROTINFO, sizeof(portstate), &portstate); + + nlh->nlmsg_len = skb->tail - b; + + return skb->len; + +nlmsg_failure: +rtattr_failure: + + skb_trim(skb, b - skb->data); + return -EINVAL; +} + +/* + * Notify listeners of a change in port information + */ +void br_ifinfo_notify(int event, struct net_bridge_port *port) +{ + struct sk_buff *skb; + int err = -ENOMEM; + + pr_debug("bridge notify event=%d\n", event); + skb = alloc_skb(NLMSG_SPACE(sizeof(struct ifinfomsg) + 128), + GFP_ATOMIC); + if (!skb) + goto err_out; + + err = br_fill_ifinfo(skb, port, current->pid, 0, event, 0); + if (err) + goto err_kfree; + + NETLINK_CB(skb).dst_group = RTNLGRP_LINK; + netlink_broadcast(rtnl, skb, 0, RTNLGRP_LINK, GFP_ATOMIC); + return; + +err_kfree: + kfree_skb(skb); +err_out: + netlink_set_err(rtnl, 0, RTNLGRP_LINK, err); +} + +/* + * Dump information about all ports, in response to GETLINK + */ +static int br_dump_ifinfo(struct sk_buff *skb, struct netlink_callback *cb) +{ + struct net_device *dev; + int idx; + int s_idx = cb->args[0]; + int err = 0; + + read_lock(&dev_base_lock); + for (dev = dev_base, idx = 0; dev; dev = dev->next) { + struct net_bridge_port *p = dev->br_port; + + /* not a bridge port */ + if (!p) + continue; + + if (idx < s_idx) + continue; + + err = br_fill_ifinfo(skb, p, NETLINK_CB(cb->skb).pid, + cb->nlh->nlmsg_seq, RTM_NEWLINK, NLM_F_MULTI); + if (err <= 0) + break; + ++idx; + } + read_unlock(&dev_base_lock); + + cb->args[0] = idx; + + return skb->len; +} + +/* + * Change state of port (ie from forwarding to blocking etc) + * Used by spanning tree in user space. + */ +static int br_rtm_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) +{ + struct rtattr **rta = arg; + struct ifinfomsg *ifm = NLMSG_DATA(nlh); + struct net_device *dev; + struct net_bridge_port *p; + u8 new_state; + + if (ifm->ifi_family != AF_BRIDGE) + return -EPFNOSUPPORT; + + /* Must pass valid state as PROTINFO */ + if (rta[IFLA_PROTINFO-1]) { + u8 *pstate = RTA_DATA(rta[IFLA_PROTINFO-1]); + new_state = *pstate; + } else + return -EINVAL; + + if (new_state > BR_STATE_BLOCKING) + return -EINVAL; + + /* Find bridge port */ + dev = __dev_get_by_index(ifm->ifi_index); + if (!dev) + return -ENODEV; + + p = dev->br_port; + if (!p) + return -EINVAL; + + /* if kernel STP is running, don't allow changes */ + if (p->br->stp_enabled) + return -EBUSY; + + if (!netif_running(dev)) + return -ENETDOWN; + + if (!netif_carrier_ok(dev) && new_state != BR_STATE_DISABLED) + return -ENETDOWN; + + p->state = new_state; + br_log_state(p); + return 0; +} + + +static struct rtnetlink_link bridge_rtnetlink_table[RTM_NR_MSGTYPES] = { + [RTM_GETLINK - RTM_BASE] = { .dumpit = br_dump_ifinfo, }, + [RTM_SETLINK - RTM_BASE] = { .doit = br_rtm_setlink, }, +}; + +void __init br_netlink_init(void) +{ + rtnetlink_links[PF_BRIDGE] = bridge_rtnetlink_table; +} + +void __exit br_netlink_fini(void) +{ + rtnetlink_links[PF_BRIDGE] = NULL; +} + diff --git a/net/bridge/br_notify.c b/net/bridge/br_notify.c index a43a9c1d50d7..20278494e4da 100644 --- a/net/bridge/br_notify.c +++ b/net/bridge/br_notify.c @@ -14,6 +14,7 @@ */ #include +#include #include "br_private.h" @@ -49,6 +50,7 @@ static int br_device_event(struct notifier_block *unused, unsigned long event, v case NETDEV_CHANGEADDR: br_fdb_changeaddr(p, dev->dev_addr); + br_ifinfo_notify(RTM_NEWLINK, p); br_stp_recalculate_bridge_id(br); break; diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 22071d156828..c491fb2f280e 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -29,7 +29,7 @@ #define BR_PORT_DEBOUNCE (HZ/10) -#define BR_VERSION "2.1" +#define BR_VERSION "2.2" typedef struct bridge_id bridge_id; typedef struct mac_addr mac_addr; @@ -237,6 +237,11 @@ extern struct net_bridge_fdb_entry *(*br_fdb_get_hook)(struct net_bridge *br, extern void (*br_fdb_put_hook)(struct net_bridge_fdb_entry *ent); +/* br_netlink.c */ +extern void br_netlink_init(void); +extern void br_netlink_fini(void); +extern void br_ifinfo_notify(int event, struct net_bridge_port *port); + #ifdef CONFIG_SYSFS /* br_sysfs_if.c */ extern struct sysfs_ops brport_sysfs_ops; diff --git a/net/bridge/br_stp_if.c b/net/bridge/br_stp_if.c index 23dea1422c9a..14cd025079af 100644 --- a/net/bridge/br_stp_if.c +++ b/net/bridge/br_stp_if.c @@ -16,6 +16,7 @@ #include #include #include +#include #include "br_private.h" #include "br_private_stp.h" @@ -86,6 +87,7 @@ void br_stp_disable_bridge(struct net_bridge *br) void br_stp_enable_port(struct net_bridge_port *p) { br_init_port(p); + br_ifinfo_notify(RTM_NEWLINK, p); br_port_state_selection(p->br); } @@ -99,6 +101,8 @@ void br_stp_disable_port(struct net_bridge_port *p) printk(KERN_INFO "%s: port %i(%s) entering %s state\n", br->dev->name, p->port_no, p->dev->name, "disabled"); + br_ifinfo_notify(RTM_DELLINK, p); + wasroot = br_is_root_bridge(br); br_become_designated_port(p); p->state = BR_STATE_DISABLED;