From 33f72e6f0c67f673fd0c63a8182dbd9ffb8cf50b Mon Sep 17 00:00:00 2001 From: Bill Hong Date: Sat, 27 Dec 2014 10:12:39 -0800 Subject: [PATCH] l2tp : multicast notification to the registered listeners Previously l2tp module did not provide any means for the user space to get notified when tunnels/sessions are added/modified/deleted. This change contains the following - create a multicast group for the listeners to register. - notify the registered listeners when the tunnels/sessions are created/modified/deleted. Signed-off-by: Bill Hong Reviewed-by: Stephen Hemminger Reviewed-by: Sven-Thorsten Dietrich Signed-off-by: David S. Miller --- include/uapi/linux/l2tp.h | 1 + net/l2tp/l2tp_netlink.c | 101 ++++++++++++++++++++++++++++++++++---- 2 files changed, 92 insertions(+), 10 deletions(-) diff --git a/include/uapi/linux/l2tp.h b/include/uapi/linux/l2tp.h index 21caa2631c20..347ef22a964e 100644 --- a/include/uapi/linux/l2tp.h +++ b/include/uapi/linux/l2tp.h @@ -178,5 +178,6 @@ enum l2tp_seqmode { */ #define L2TP_GENL_NAME "l2tp" #define L2TP_GENL_VERSION 0x1 +#define L2TP_GENL_MCGROUP "l2tp" #endif /* _UAPI_LINUX_L2TP_H_ */ diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c index 0ac907adb2f4..6b16598f31d5 100644 --- a/net/l2tp/l2tp_netlink.c +++ b/net/l2tp/l2tp_netlink.c @@ -40,6 +40,18 @@ static struct genl_family l2tp_nl_family = { .netnsok = true, }; +static const struct genl_multicast_group l2tp_multicast_group[] = { + { + .name = L2TP_GENL_MCGROUP, + }, +}; + +static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, + int flags, struct l2tp_tunnel *tunnel, u8 cmd); +static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, + int flags, struct l2tp_session *session, + u8 cmd); + /* Accessed under genl lock */ static const struct l2tp_nl_cmd_ops *l2tp_nl_cmd_ops[__L2TP_PWTYPE_MAX]; @@ -97,6 +109,52 @@ out: return ret; } +static int l2tp_tunnel_notify(struct genl_family *family, + struct genl_info *info, + struct l2tp_tunnel *tunnel, + u8 cmd) +{ + struct sk_buff *msg; + int ret; + + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!msg) + return -ENOMEM; + + ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq, + NLM_F_ACK, tunnel, cmd); + + if (ret >= 0) + return genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC); + + nlmsg_free(msg); + + return ret; +} + +static int l2tp_session_notify(struct genl_family *family, + struct genl_info *info, + struct l2tp_session *session, + u8 cmd) +{ + struct sk_buff *msg; + int ret; + + msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); + if (!msg) + return -ENOMEM; + + ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq, + NLM_F_ACK, session, cmd); + + if (ret >= 0) + return genlmsg_multicast_allns(family, msg, 0, 0, GFP_ATOMIC); + + nlmsg_free(msg); + + return ret; +} + static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info) { u32 tunnel_id; @@ -188,6 +246,9 @@ static int l2tp_nl_cmd_tunnel_create(struct sk_buff *skb, struct genl_info *info break; } + if (ret >= 0) + ret = l2tp_tunnel_notify(&l2tp_nl_family, info, + tunnel, L2TP_CMD_TUNNEL_CREATE); out: return ret; } @@ -211,6 +272,9 @@ static int l2tp_nl_cmd_tunnel_delete(struct sk_buff *skb, struct genl_info *info goto out; } + l2tp_tunnel_notify(&l2tp_nl_family, info, + tunnel, L2TP_CMD_TUNNEL_DELETE); + (void) l2tp_tunnel_delete(tunnel); out: @@ -239,12 +303,15 @@ static int l2tp_nl_cmd_tunnel_modify(struct sk_buff *skb, struct genl_info *info if (info->attrs[L2TP_ATTR_DEBUG]) tunnel->debug = nla_get_u32(info->attrs[L2TP_ATTR_DEBUG]); + ret = l2tp_tunnel_notify(&l2tp_nl_family, info, + tunnel, L2TP_CMD_TUNNEL_MODIFY); + out: return ret; } static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int flags, - struct l2tp_tunnel *tunnel) + struct l2tp_tunnel *tunnel, u8 cmd) { void *hdr; struct nlattr *nest; @@ -254,8 +321,7 @@ static int l2tp_nl_tunnel_send(struct sk_buff *skb, u32 portid, u32 seq, int fla struct ipv6_pinfo *np = NULL; #endif - hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, - L2TP_CMD_TUNNEL_GET); + hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd); if (!hdr) return -EMSGSIZE; @@ -359,7 +425,7 @@ static int l2tp_nl_cmd_tunnel_get(struct sk_buff *skb, struct genl_info *info) } ret = l2tp_nl_tunnel_send(msg, info->snd_portid, info->snd_seq, - NLM_F_ACK, tunnel); + NLM_F_ACK, tunnel, L2TP_CMD_TUNNEL_GET); if (ret < 0) goto err_out; @@ -385,7 +451,7 @@ static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, NLM_F_MULTI, - tunnel) <= 0) + tunnel, L2TP_CMD_TUNNEL_GET) <= 0) goto out; ti++; @@ -539,6 +605,13 @@ static int l2tp_nl_cmd_session_create(struct sk_buff *skb, struct genl_info *inf ret = (*l2tp_nl_cmd_ops[cfg.pw_type]->session_create)(net, tunnel_id, session_id, peer_session_id, &cfg); + if (ret >= 0) { + session = l2tp_session_find(net, tunnel, session_id); + if (session) + ret = l2tp_session_notify(&l2tp_nl_family, info, session, + L2TP_CMD_SESSION_CREATE); + } + out: return ret; } @@ -555,6 +628,9 @@ static int l2tp_nl_cmd_session_delete(struct sk_buff *skb, struct genl_info *inf goto out; } + l2tp_session_notify(&l2tp_nl_family, info, + session, L2TP_CMD_SESSION_DELETE); + pw_type = session->pwtype; if (pw_type < __L2TP_PWTYPE_MAX) if (l2tp_nl_cmd_ops[pw_type] && l2tp_nl_cmd_ops[pw_type]->session_delete) @@ -601,12 +677,15 @@ static int l2tp_nl_cmd_session_modify(struct sk_buff *skb, struct genl_info *inf if (info->attrs[L2TP_ATTR_MRU]) session->mru = nla_get_u16(info->attrs[L2TP_ATTR_MRU]); + ret = l2tp_session_notify(&l2tp_nl_family, info, + session, L2TP_CMD_SESSION_MODIFY); + out: return ret; } static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int flags, - struct l2tp_session *session) + struct l2tp_session *session, u8 cmd) { void *hdr; struct nlattr *nest; @@ -615,7 +694,7 @@ static int l2tp_nl_session_send(struct sk_buff *skb, u32 portid, u32 seq, int fl sk = tunnel->sock; - hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, L2TP_CMD_SESSION_GET); + hdr = genlmsg_put(skb, portid, seq, &l2tp_nl_family, flags, cmd); if (!hdr) return -EMSGSIZE; @@ -699,7 +778,7 @@ static int l2tp_nl_cmd_session_get(struct sk_buff *skb, struct genl_info *info) } ret = l2tp_nl_session_send(msg, info->snd_portid, info->snd_seq, - 0, session); + 0, session, L2TP_CMD_SESSION_GET); if (ret < 0) goto err_out; @@ -737,7 +816,7 @@ static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback if (l2tp_nl_session_send(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, NLM_F_MULTI, - session) <= 0) + session, L2TP_CMD_SESSION_GET) <= 0) break; si++; @@ -896,7 +975,9 @@ EXPORT_SYMBOL_GPL(l2tp_nl_unregister_ops); static int l2tp_nl_init(void) { pr_info("L2TP netlink interface\n"); - return genl_register_family_with_ops(&l2tp_nl_family, l2tp_nl_ops); + return genl_register_family_with_ops_groups(&l2tp_nl_family, + l2tp_nl_ops, + l2tp_multicast_group); } static void l2tp_nl_cleanup(void) -- 2.20.1