Return-path: Received: from mx1.uni-rostock.de ([139.30.22.71]:64798 "EHLO mx1.uni-rostock.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965569AbeAJQnp (ORCPT ); Wed, 10 Jan 2018 11:43:45 -0500 From: Benjamin Beichler To: CC: , Benjamin Beichler Subject: [PATCH v3 3/5] mac80211_hwsim: add generation count for netlink dump operation Date: Wed, 10 Jan 2018 17:42:53 +0100 In-Reply-To: <20180110164255.2763-1-benjamin.beichler@uni-rostock.de> References: <20180110164255.2763-1-benjamin.beichler@uni-rostock.de> MIME-Version: 1.0 Content-Type: text/plain Message-ID: <44644db1-58a4-4b6e-a77e-37c72ee2e4a6@MAIL2.uni-rostock.de> (sfid-20180110_174350_143330_B3370AD3) Sender: linux-wireless-owner@vger.kernel.org List-ID: Make the dump operation aware of changes on radio list and corresponding inconsistent dumps. Change the dump iteration to be independent from increasing radio indices on radio list. Signed-off-by: Benjamin Beichler --- drivers/net/wireless/mac80211_hwsim.c | 43 ++++++++++++++++++++++++----------- 1 file changed, 30 insertions(+), 13 deletions(-) diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 55d25e3fbbcc..2d4e97b6dc8f 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -493,6 +493,7 @@ static LIST_HEAD(hwsim_radios); static struct workqueue_struct *hwsim_wq; static struct rhashtable hwsim_radios_rht; static int hwsim_radio_idx; +static int hwsim_radios_generation = 1; static struct platform_driver mac80211_hwsim_driver = { .driver = { @@ -2758,6 +2759,7 @@ static int mac80211_hwsim_new_radio(struct genl_info *info, } list_add_tail(&data->list, &hwsim_radios); + hwsim_radios_generation++; spin_unlock_bh(&hwsim_radio_lock); if (idx > 0) @@ -3209,6 +3211,7 @@ static int hwsim_del_radio_nl(struct sk_buff *msg, struct genl_info *info) list_del(&data->list); rhashtable_remove_fast(&hwsim_radios_rht, &data->rht, hwsim_rht_params); + hwsim_radios_generation++; spin_unlock_bh(&hwsim_radio_lock); mac80211_hwsim_del_radio(data, wiphy_name(data->hw->wiphy), info); @@ -3265,19 +3268,34 @@ static int hwsim_get_radio_nl(struct sk_buff *msg, struct genl_info *info) static int hwsim_dump_radio_nl(struct sk_buff *skb, struct netlink_callback *cb) { - int idx = cb->args[0]; - struct mac80211_hwsim_data *data = NULL; - int res; + struct mac80211_hwsim_data *data = + (struct mac80211_hwsim_data *)cb->args[0]; + int res = 0; + void *hdr; spin_lock_bh(&hwsim_radio_lock); + cb->seq = hwsim_radios_generation; + + /* list changed, send msg with dump interrupted header*/ + if (cb->prev_seq && cb->seq != cb->prev_seq) { + hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, + cb->nlh->nlmsg_seq, &hwsim_genl_family, + NLM_F_MULTI, HWSIM_CMD_GET_RADIO); + if (!hdr) + res = -EMSGSIZE; + genl_dump_check_consistent(cb, hdr); + genlmsg_end(skb, hdr); + goto cleanup; + } - if (idx == hwsim_radio_idx) - goto done; + /* iterator is at head again, finish*/ + if (data && &data->list == &hwsim_radios) + goto cleanup; - list_for_each_entry(data, &hwsim_radios, list) { - if (data->idx < idx) - continue; + /* data will NULL or valid since we quit, if list changed */ + data = list_prepare_entry(data, &hwsim_radios, list); + list_for_each_entry_continue(data, &hwsim_radios, list) { if (!net_eq(wiphy_net(data->hw->wiphy), sock_net(skb->sk))) continue; @@ -3287,15 +3305,13 @@ static int hwsim_dump_radio_nl(struct sk_buff *skb, NLM_F_MULTI); if (res < 0) break; - - idx = data->idx + 1; } - cb->args[0] = idx; + cb->args[0] = (long)data; -done: +cleanup: spin_unlock_bh(&hwsim_radio_lock); - return skb->len; + return (res)? res : skb->len; } /* Generic Netlink operations array */ @@ -3353,6 +3369,7 @@ static void destroy_radio(struct work_struct *work) struct mac80211_hwsim_data *data = container_of(work, struct mac80211_hwsim_data, destroy_work); + hwsim_radios_generation++; mac80211_hwsim_del_radio(data, wiphy_name(data->hw->wiphy), NULL); } -- 2.15.1