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authorThomas Graf <tgraf@suug.ch>2005-11-05 21:14:13 +0100
committerThomas Graf <tgr@axs.localdomain>2005-11-05 22:02:26 +0100
commit6639607ed9deaed9ab3a1cc588f0288891ece2ac (patch)
tree370e98cbb4143cf397d5b3cf2a3a8ddf66a13cf1 /net/sched
parente06368221c204d7b5f1ba37d047170f9a0dd359d (diff)
[PKT_SCHED]: GRED: Use a central table definition change procedure
Introduces a function gred_change_table_def() acting as a central point to change the table definition. Adds missing validations for table definition: MAX_DPs > DPs > 0 and def_DP < DPs thus fixing possible invalid memory reference oopses. Only root could do it but having a typo crashing the machine is a bit hard. Adds missing locking while changing the table definition, the operation of changing the number of DPs and removing shadowed VQs may not be interrupted by a dequeue. Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>
Diffstat (limited to 'net/sched')
-rw-r--r--net/sched/sch_gred.c113
1 files changed, 61 insertions, 52 deletions
diff --git a/net/sched/sch_gred.c b/net/sched/sch_gred.c
index a1369550ce7..fdc20ced52e 100644
--- a/net/sched/sch_gred.c
+++ b/net/sched/sch_gred.c
@@ -378,43 +378,72 @@ static void gred_reset(struct Qdisc* sch)
}
}
-static int gred_change(struct Qdisc *sch, struct rtattr *opt)
+static inline void gred_destroy_vq(struct gred_sched_data *q)
+{
+ kfree(q);
+}
+
+static inline int gred_change_table_def(struct Qdisc *sch, struct rtattr *dps)
{
struct gred_sched *table = qdisc_priv(sch);
- struct gred_sched_data *q;
- struct tc_gred_qopt *ctl;
struct tc_gred_sopt *sopt;
- struct rtattr *tb[TCA_GRED_STAB];
- struct rtattr *tb2[TCA_GRED_DPS];
+ int i;
- if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_STAB, opt))
+ if (dps == NULL || RTA_PAYLOAD(dps) < sizeof(*sopt))
return -EINVAL;
- if (tb[TCA_GRED_PARMS-1] == 0 && tb[TCA_GRED_STAB-1] == 0) {
- rtattr_parse_nested(tb2, TCA_GRED_DPS, opt);
+ sopt = RTA_DATA(dps);
- if (tb2[TCA_GRED_DPS-1] == 0)
- return -EINVAL;
+ if (sopt->DPs > MAX_DPs || sopt->DPs == 0 || sopt->def_DP >= sopt->DPs)
+ return -EINVAL;
- sopt = RTA_DATA(tb2[TCA_GRED_DPS-1]);
- table->DPs=sopt->DPs;
- table->def=sopt->def_DP;
+ sch_tree_lock(sch);
+ table->DPs = sopt->DPs;
+ table->def = sopt->def_DP;
- if (sopt->grio) {
- gred_enable_rio_mode(table);
- gred_disable_wred_mode(table);
- if (gred_wred_mode_check(sch))
- gred_enable_wred_mode(table);
- } else {
- gred_disable_rio_mode(table);
- gred_disable_wred_mode(table);
- }
+ /*
+ * Every entry point to GRED is synchronized with the above code
+ * and the DP is checked against DPs, i.e. shadowed VQs can no
+ * longer be found so we can unlock right here.
+ */
+ sch_tree_unlock(sch);
- table->initd=0;
- /* probably need to clear all the table DP entries as well */
- return 0;
- }
+ if (sopt->grio) {
+ gred_enable_rio_mode(table);
+ gred_disable_wred_mode(table);
+ if (gred_wred_mode_check(sch))
+ gred_enable_wred_mode(table);
+ } else {
+ gred_disable_rio_mode(table);
+ gred_disable_wred_mode(table);
+ }
+
+ for (i = table->DPs; i < MAX_DPs; i++) {
+ if (table->tab[i]) {
+ printk(KERN_WARNING "GRED: Warning: Destroying "
+ "shadowed VQ 0x%x\n", i);
+ gred_destroy_vq(table->tab[i]);
+ table->tab[i] = NULL;
+ }
+ }
+ table->initd = 0;
+
+ return 0;
+}
+
+static int gred_change(struct Qdisc *sch, struct rtattr *opt)
+{
+ struct gred_sched *table = qdisc_priv(sch);
+ struct gred_sched_data *q;
+ struct tc_gred_qopt *ctl;
+ struct rtattr *tb[TCA_GRED_STAB];
+
+ if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_STAB, opt))
+ return -EINVAL;
+
+ if (tb[TCA_GRED_PARMS-1] == NULL && tb[TCA_GRED_STAB-1] == NULL)
+ return gred_change_table_def(sch, tb[TCA_GRED_DPS-1]);
if (!table->DPs || tb[TCA_GRED_PARMS-1] == 0 || tb[TCA_GRED_STAB-1] == 0 ||
RTA_PAYLOAD(tb[TCA_GRED_PARMS-1]) < sizeof(*ctl) ||
@@ -526,35 +555,15 @@ static int gred_change(struct Qdisc *sch, struct rtattr *opt)
static int gred_init(struct Qdisc *sch, struct rtattr *opt)
{
- struct gred_sched *table = qdisc_priv(sch);
- struct tc_gred_sopt *sopt;
- struct rtattr *tb[TCA_GRED_STAB];
- struct rtattr *tb2[TCA_GRED_DPS];
+ struct rtattr *tb[TCA_GRED_MAX];
- if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_STAB, opt))
+ if (opt == NULL || rtattr_parse_nested(tb, TCA_GRED_MAX, opt))
return -EINVAL;
- if (tb[TCA_GRED_PARMS-1] == 0 && tb[TCA_GRED_STAB-1] == 0) {
- rtattr_parse_nested(tb2, TCA_GRED_DPS, opt);
-
- if (tb2[TCA_GRED_DPS-1] == 0)
- return -EINVAL;
-
- sopt = RTA_DATA(tb2[TCA_GRED_DPS-1]);
- table->DPs=sopt->DPs;
- table->def=sopt->def_DP;
-
- if (sopt->grio)
- gred_enable_rio_mode(table);
- else
- gred_disable_rio_mode(table);
-
- table->initd=0;
- return 0;
- }
+ if (tb[TCA_GRED_PARMS-1] || tb[TCA_GRED_STAB-1])
+ return -EINVAL;
- DPRINTK("\n GRED_INIT error!\n");
- return -EINVAL;
+ return gred_change_table_def(sch, tb[TCA_GRED_DPS-1]);
}
static int gred_dump(struct Qdisc *sch, struct sk_buff *skb)
@@ -641,7 +650,7 @@ static void gred_destroy(struct Qdisc *sch)
for (i = 0;i < table->DPs; i++) {
if (table->tab[i])
- kfree(table->tab[i]);
+ gred_destroy_vq(table->tab[i]);
}
}