From 54a4b05cd281a352d803417a98a72878fb0802cf Mon Sep 17 00:00:00 2001 From: Yang Yingliang Date: Fri, 14 Feb 2014 10:30:41 +0800 Subject: [PATCH] sch_netem: return errcode before setting params get_dist_table() and get_loss_clg() may be failed. These two functions should be called after setting the members of qdisc_priv(sch), or it will break the old settings while either of them is failed. Signed-off-by: Yang Yingliang Signed-off-by: David S. Miller --- net/sched/sch_netem.c | 39 +++++++++++++++++++++++++++++---------- 1 file changed, 29 insertions(+), 10 deletions(-) diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c index de1059af6da1..b341943555a9 100644 --- a/net/sched/sch_netem.c +++ b/net/sched/sch_netem.c @@ -821,6 +821,8 @@ static int netem_change(struct Qdisc *sch, struct nlattr *opt) struct netem_sched_data *q = qdisc_priv(sch); struct nlattr *tb[TCA_NETEM_MAX + 1]; struct tc_netem_qopt *qopt; + struct clgstate old_clg; + int old_loss_model = CLG_RANDOM; int ret; if (opt == NULL) @@ -831,6 +833,33 @@ static int netem_change(struct Qdisc *sch, struct nlattr *opt) if (ret < 0) return ret; + /* backup q->clg and q->loss_model */ + old_clg = q->clg; + old_loss_model = q->loss_model; + + if (tb[TCA_NETEM_LOSS]) { + ret = get_loss_clg(sch, tb[TCA_NETEM_LOSS]); + if (ret) { + q->loss_model = old_loss_model; + return ret; + } + } else { + q->loss_model = CLG_RANDOM; + } + + if (tb[TCA_NETEM_DELAY_DIST]) { + ret = get_dist_table(sch, tb[TCA_NETEM_DELAY_DIST]); + if (ret) { + /* recover clg and loss_model, in case of + * q->clg and q->loss_model were modified + * in get_loss_clg() + */ + q->clg = old_clg; + q->loss_model = old_loss_model; + return ret; + } + } + sch->limit = qopt->limit; q->latency = qopt->latency; @@ -850,12 +879,6 @@ static int netem_change(struct Qdisc *sch, struct nlattr *opt) if (tb[TCA_NETEM_CORR]) get_correlation(sch, tb[TCA_NETEM_CORR]); - if (tb[TCA_NETEM_DELAY_DIST]) { - ret = get_dist_table(sch, tb[TCA_NETEM_DELAY_DIST]); - if (ret) - return ret; - } - if (tb[TCA_NETEM_REORDER]) get_reorder(sch, tb[TCA_NETEM_REORDER]); @@ -872,10 +895,6 @@ static int netem_change(struct Qdisc *sch, struct nlattr *opt) if (tb[TCA_NETEM_ECN]) q->ecn = nla_get_u32(tb[TCA_NETEM_ECN]); - q->loss_model = CLG_RANDOM; - if (tb[TCA_NETEM_LOSS]) - ret = get_loss_clg(sch, tb[TCA_NETEM_LOSS]); - return ret; }