diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/ipoe/ipoe.c | 175 | ||||
| -rw-r--r-- | drivers/ipoe/ipoe.h | 1 |
2 files changed, 175 insertions, 1 deletions
diff --git a/drivers/ipoe/ipoe.c b/drivers/ipoe/ipoe.c index 2829e6ac..251fec96 100644 --- a/drivers/ipoe/ipoe.c +++ b/drivers/ipoe/ipoe.c @@ -22,6 +22,7 @@ #include <linux/version.h> #include <net/genetlink.h> +#include <net/rtnetlink.h> #include <net/route.h> #include <net/sock.h> #include <net/ip.h> @@ -104,6 +105,10 @@ struct ipoe_session { atomic_t refs; + /* set under ipoe_wlock by whoever starts tearing the session down, + * so that the genl and the rtnetlink path do not do it twice */ + unsigned int dying:1; + struct ipoe_stats __percpu *rx_stats; struct ipoe_stats __percpu *tx_stats; }; @@ -1116,6 +1121,83 @@ static const struct header_ops ipoe_hard_header_ops = { .cache_update = eth_header_cache_update, }; +/* Is anybody subscribed to our packet group, i.e. is a control daemon + * running at all? */ +static int ipoe_ctrl_attached(void) +{ +#if LINUX_VERSION_CODE < KERNEL_VERSION(3,13,0) && RHEL_MAJOR < 7 + return netlink_has_listeners(init_net.genl_sock, ipoe_nl_mcg.id); +#else + return genl_has_listeners(&ipoe_nl_family, &init_net, 0); +#endif +} + +/* Sessions are created through IPOE_CMD_CREATE, which also sets up the + * private state. A device made by rtnetlink would have none of it, so + * refuse 'ip link add ... type ipoe' explicitly. */ +#if LINUX_VERSION_CODE >= KERNEL_VERSION(6,13,0) +static int ipoe_newlink(struct net_device *dev, + struct rtnl_newlink_params *params, + struct netlink_ext_ack *extack) +#elif LINUX_VERSION_CODE >= KERNEL_VERSION(4,13,0) +static int ipoe_newlink(struct net *src_net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[], + struct netlink_ext_ack *extack) +#else +static int ipoe_newlink(struct net *src_net, struct net_device *dev, + struct nlattr *tb[], struct nlattr *data[]) +#endif +{ + return -EOPNOTSUPP; +} + +/* Called by rtnetlink with rtnl held, so the teardown ipoe_nl_cmd_delete() + * does after dropping ipoe_wlock has to happen here as well. */ +static void ipoe_dellink(struct net_device *dev, struct list_head *head) +{ + struct ipoe_session *ses = netdev_priv(dev); + + down(&ipoe_wlock); + + if (ses->dying) { + /* the genl path is already removing it, it will unregister + * the device itself once it gets rtnl */ + up(&ipoe_wlock); + return; + } + + ses->dying = 1; + + if (ses->peer_addr) + list_del_rcu(&ses->entry); + list_del(&ses->entry2); + if (ses->u.hwaddr_u) + list_del_rcu(&ses->entry3); + + up(&ipoe_wlock); + + /* A session left behind by a dead daemon looks exactly like one that + * is still in use, so removing it can not be refused on state alone. + * Complain only if somebody is still subscribed to our multicast + * group, which means a daemon is around to be surprised by it. */ + if (ses->peer_addr && ipoe_ctrl_attached()) + pr_warn("ipoe: %s: removed through rtnetlink while bound to %pI4" + " and a control daemon is attached\n", + dev->name, &ses->peer_addr); + + synchronize_rcu(); + + while (atomic_read(&ses->refs)) + schedule_timeout_uninterruptible(1); + + if (ses->link_dev) { + dev_put(ses->link_dev); + ses->link_dev = NULL; + } + + unregister_netdevice_queue(dev, head); +} + static void ipoe_netdev_setup(struct net_device *dev) { dev->netdev_ops = &ipoe_netdev_ops; @@ -1145,6 +1227,14 @@ static void ipoe_netdev_setup(struct net_device *dev) dev->priv_flags &= ~IFF_XMIT_DST_RELEASE; } +static struct rtnl_link_ops ipoe_link_ops __read_mostly = { + .kind = "ipoe", + .priv_size = sizeof(struct ipoe_session), + .setup = ipoe_netdev_setup, + .newlink = ipoe_newlink, + .dellink = ipoe_dellink, +}; + static int ipoe_create(__be32 peer_addr, __be32 addr, __be32 gw, int ifindex, const __u8 *hwaddr) { struct ipoe_session *ses; @@ -1220,6 +1310,7 @@ static int ipoe_create(__be32 peer_addr, __be32 addr, __be32 gw, int ifindex, co }*/ dev->tx_queue_len = 100; + dev->rtnl_link_ops = &ipoe_link_ops; rtnl_lock(); r = register_netdevice(dev); @@ -1393,12 +1484,22 @@ static int ipoe_nl_cmd_delete(struct sk_buff *skb, struct genl_info *info) //pr_info("ipoe: delete %08x\n", ses->peer_addr); + if (ses->dying) { + /* already on its way out through ipoe_dellink() or a flush */ + ret = 0; + goto out_unlock; + } + + ses->dying = 1; + if (ses->peer_addr) list_del_rcu(&ses->entry); list_del(&ses->entry2); if (ses->u.hwaddr_u) list_del_rcu(&ses->entry3); + /* drop the lock before sleeping in synchronize_rcu() and taking rtnl + * in unregister_netdev() */ up(&ipoe_wlock); synchronize_rcu(); @@ -1411,13 +1512,61 @@ static int ipoe_nl_cmd_delete(struct sk_buff *skb, struct genl_info *info) unregister_netdev(ses->dev); - ret = 0; + return 0; out_unlock: up(&ipoe_wlock); return ret; } +static int ipoe_nl_cmd_flush(struct sk_buff *skb, struct genl_info *info) +{ + struct ipoe_session *ses; + LIST_HEAD(list); + LIST_HEAD(kill_list); + + down(&ipoe_wlock); + + list_splice_init(&ipoe_list2, &list); + + list_for_each_entry(ses, &list, entry2) { + ses->dying = 1; + + if (ses->peer_addr) + list_del_rcu(&ses->entry); + if (ses->u.hwaddr_u) + list_del_rcu(&ses->entry3); + } + + up(&ipoe_wlock); + + if (list_empty(&list)) + return 0; + + /* a single grace period covers the whole batch */ + synchronize_rcu(); + + list_for_each_entry(ses, &list, entry2) { + while (atomic_read(&ses->refs)) + schedule_timeout_uninterruptible(1); + + if (ses->link_dev) { + dev_put(ses->link_dev); + ses->link_dev = NULL; + } + } + + rtnl_lock(); + list_for_each_entry(ses, &list, entry2) + unregister_netdevice_queue(ses->dev, &kill_list); + unregister_netdevice_many(&kill_list); + rtnl_unlock(); + + /* the sessions are freed by now, do not touch 'list' again */ + + return 0; +} + static int ipoe_nl_cmd_modify(struct sk_buff *skb, struct genl_info *info) { int ret = -EINVAL, r = 0; @@ -1577,7 +1726,11 @@ static int ipoe_nl_cmd_dump_sessions(struct sk_buff *skb, struct netlink_callbac #else if (fill_info(skb, ses, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq) < 0) #endif + { + /* this one did not fit, resume from it next time */ + idx--; break; + } } up(&ipoe_wlock); @@ -1890,6 +2043,14 @@ static const struct genl_ops ipoe_nl_ops[] = { .policy = ipoe_nl_policy, #endif }, + { + .cmd = IPOE_CMD_FLUSH, + .doit = ipoe_nl_cmd_flush, + .flags = GENL_ADMIN_PERM, +#if LINUX_VERSION_CODE < KERNEL_VERSION(5,2,0) + .policy = ipoe_nl_policy, +#endif + }, }; #if LINUX_VERSION_CODE < KERNEL_VERSION(3,13,0) && RHEL_MAJOR < 7 @@ -1960,6 +2121,12 @@ static int __init ipoe_init(void) skb_queue_head_init(&ipoe_queue); INIT_WORK(&ipoe_queue_work, ipoe_process_queue); + err = rtnl_link_register(&ipoe_link_ops); + if (err < 0) { + printk(KERN_INFO "ipoe: can't register link operations\n"); + return err; + } + #if LINUX_VERSION_CODE < KERNEL_VERSION(3,13,0) && RHEL_MAJOR < 7 err = genl_register_family_with_ops(&ipoe_nl_family, ipoe_nl_ops, ARRAY_SIZE(ipoe_nl_ops)); #elif LINUX_VERSION_CODE < KERNEL_VERSION(4,10,0) @@ -1969,6 +2136,7 @@ static int __init ipoe_init(void) #endif if (err < 0) { printk(KERN_INFO "ipoe: can't register netlink interface\n"); + rtnl_link_unregister(&ipoe_link_ops); return err; } @@ -1977,6 +2145,7 @@ static int __init ipoe_init(void) if (err < 0) { printk(KERN_INFO "ipoe: can't register netlink multicast group\n"); genl_unregister_family(&ipoe_nl_family); + rtnl_link_unregister(&ipoe_link_ops); return err; } #endif @@ -1996,6 +2165,10 @@ static void __exit ipoe_fini(void) #endif genl_unregister_family(&ipoe_nl_family); + /* takes down whatever sessions are left through ipoe_dellink() and + * keeps rtnetlink from starting another one behind our back */ + rtnl_link_unregister(&ipoe_link_ops); + down(&ipoe_wlock); up(&ipoe_wlock); diff --git a/drivers/ipoe/ipoe.h b/drivers/ipoe/ipoe.h index 4097e2da..2d041c50 100644 --- a/drivers/ipoe/ipoe.h +++ b/drivers/ipoe/ipoe.h @@ -16,6 +16,7 @@ enum { IPOE_CMD_DEL_EXCLUDE, IPOE_CMD_ADD_NET, IPOE_CMD_DEL_NET, + IPOE_CMD_FLUSH, __IPOE_CMD_MAX, }; |