From bc10ed7d3d19ff61427007b4d7bf98d3e57bb333 Mon Sep 17 00:00:00 2001 From: Kaike Wan Date: Fri, 14 Aug 2015 08:52:07 -0400 Subject: [PATCH] IB/core: Add rdma netlink helper functions This patch adds a function to check if listeners for a netlink multicast group are present. It also adds a function to receive netlink response messages. Signed-off-by: Kaike Wan Signed-off-by: John Fleck Signed-off-by: Ira Weiny Signed-off-by: Doug Ledford --- drivers/infiniband/core/netlink.c | 55 +++++++++++++++++++++++++++++++ include/rdma/rdma_netlink.h | 7 ++++ 2 files changed, 62 insertions(+) diff --git a/drivers/infiniband/core/netlink.c b/drivers/infiniband/core/netlink.c index 23dd5a5c7597..d47df9356779 100644 --- a/drivers/infiniband/core/netlink.c +++ b/drivers/infiniband/core/netlink.c @@ -49,6 +49,14 @@ static DEFINE_MUTEX(ibnl_mutex); static struct sock *nls; static LIST_HEAD(client_list); +int ibnl_chk_listeners(unsigned int group) +{ + if (netlink_has_listeners(nls, group) == 0) + return -1; + return 0; +} +EXPORT_SYMBOL(ibnl_chk_listeners); + int ibnl_add_client(int index, int nops, const struct ibnl_client_cbs cb_table[]) { @@ -151,6 +159,23 @@ static int ibnl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) !client->cb_table[op].dump) return -EINVAL; + /* + * For response or local service set_timeout request, + * there is no need to use netlink_dump_start. + */ + if (!(nlh->nlmsg_flags & NLM_F_REQUEST) || + (index == RDMA_NL_LS && + op == RDMA_NL_LS_OP_SET_TIMEOUT)) { + struct netlink_callback cb = { + .skb = skb, + .nlh = nlh, + .dump = client->cb_table[op].dump, + .module = client->cb_table[op].module, + }; + + return cb.dump(skb, &cb); + } + { struct netlink_dump_control c = { .dump = client->cb_table[op].dump, @@ -165,9 +190,39 @@ static int ibnl_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) return -EINVAL; } +static void ibnl_rcv_reply_skb(struct sk_buff *skb) +{ + struct nlmsghdr *nlh; + int msglen; + + /* + * Process responses until there is no more message or the first + * request. Generally speaking, it is not recommended to mix responses + * with requests. + */ + while (skb->len >= nlmsg_total_size(0)) { + nlh = nlmsg_hdr(skb); + + if (nlh->nlmsg_len < NLMSG_HDRLEN || skb->len < nlh->nlmsg_len) + return; + + /* Handle response only */ + if (nlh->nlmsg_flags & NLM_F_REQUEST) + return; + + ibnl_rcv_msg(skb, nlh); + + msglen = NLMSG_ALIGN(nlh->nlmsg_len); + if (msglen > skb->len) + msglen = skb->len; + skb_pull(skb, msglen); + } +} + static void ibnl_rcv(struct sk_buff *skb) { mutex_lock(&ibnl_mutex); + ibnl_rcv_reply_skb(skb); netlink_rcv_skb(skb, &ibnl_rcv_msg); mutex_unlock(&ibnl_mutex); } diff --git a/include/rdma/rdma_netlink.h b/include/rdma/rdma_netlink.h index 0790882e0c9b..585266144329 100644 --- a/include/rdma/rdma_netlink.h +++ b/include/rdma/rdma_netlink.h @@ -77,4 +77,11 @@ int ibnl_unicast(struct sk_buff *skb, struct nlmsghdr *nlh, int ibnl_multicast(struct sk_buff *skb, struct nlmsghdr *nlh, unsigned int group, gfp_t flags); +/** + * Check if there are any listeners to the netlink group + * @group: the netlink group ID + * Returns 0 on success or a negative for no listeners. + */ +int ibnl_chk_listeners(unsigned int group); + #endif /* _RDMA_NETLINK_H */ -- 2.20.1