From 0efc7e541fd51ed11a328c43ccf10a12f1727746 Mon Sep 17 00:00:00 2001 From: Alessandro Marcolini Date: Thu, 25 Jan 2024 17:59:42 +0100 Subject: [PATCH] taprio: validate TCA_TAPRIO_ATTR_FLAGS through policy instead of open-coding As of now, the field TCA_TAPRIO_ATTR_FLAGS is being validated by manually checking its value, using the function taprio_flags_valid(). With this patch, the field will be validated through the netlink policy NLA_POLICY_MASK, where the mask is defined by TAPRIO_SUPPORTED_FLAGS. The mutual exclusivity of the two flags TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD and TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST is still checked manually. Changes since RFC: - fixed reversed xmas tree - use NL_SET_ERR_MSG_MOD() for both invalid configuration Changes since v1: - Changed NL_SET_ERR_MSG_MOD to NL_SET_ERR_MSG_ATTR when wrong flags issued - Changed __u32 to u32 Changes since v2: - Added the missing parameter for NL_SET_ERR_MSG_ATTR (sorry again for the noise) Signed-off-by: Alessandro Marcolini Reviewed-by: Simon Horman Signed-off-by: David S. Miller --- net/sched/sch_taprio.c | 72 +++++++++++++++--------------------------- 1 file changed, 26 insertions(+), 46 deletions(-) diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index 31a8252bd09c..827cb683efbf 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -40,6 +40,8 @@ static struct static_key_false taprio_have_working_mqprio; #define TXTIME_ASSIST_IS_ENABLED(flags) ((flags) & TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST) #define FULL_OFFLOAD_IS_ENABLED(flags) ((flags) & TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD) +#define TAPRIO_SUPPORTED_FLAGS \ + (TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST | TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD) #define TAPRIO_FLAGS_INVALID U32_MAX struct sched_entry { @@ -408,19 +410,6 @@ static bool is_valid_interval(struct sk_buff *skb, struct Qdisc *sch) return entry; } -static bool taprio_flags_valid(u32 flags) -{ - /* Make sure no other flag bits are set. */ - if (flags & ~(TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST | - TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD)) - return false; - /* txtime-assist and full offload are mutually exclusive */ - if ((flags & TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST) && - (flags & TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD)) - return false; - return true; -} - /* This returns the tstamp value set by TCP in terms of the set clock. */ static ktime_t get_tcp_tstamp(struct taprio_sched *q, struct sk_buff *skb) { @@ -1031,7 +1020,8 @@ static const struct nla_policy taprio_policy[TCA_TAPRIO_ATTR_MAX + 1] = { [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME] = NLA_POLICY_FULL_RANGE_SIGNED(NLA_S64, &taprio_cycle_time_range), [TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION] = { .type = NLA_S64 }, - [TCA_TAPRIO_ATTR_FLAGS] = { .type = NLA_U32 }, + [TCA_TAPRIO_ATTR_FLAGS] = + NLA_POLICY_MASK(NLA_U32, TAPRIO_SUPPORTED_FLAGS), [TCA_TAPRIO_ATTR_TXTIME_DELAY] = { .type = NLA_U32 }, [TCA_TAPRIO_ATTR_TC_ENTRY] = { .type = NLA_NESTED }, }; @@ -1815,33 +1805,6 @@ static int taprio_mqprio_cmp(const struct net_device *dev, return 0; } -/* The semantics of the 'flags' argument in relation to 'change()' - * requests, are interpreted following two rules (which are applied in - * this order): (1) an omitted 'flags' argument is interpreted as - * zero; (2) the 'flags' of a "running" taprio instance cannot be - * changed. - */ -static int taprio_new_flags(const struct nlattr *attr, u32 old, - struct netlink_ext_ack *extack) -{ - u32 new = 0; - - if (attr) - new = nla_get_u32(attr); - - if (old != TAPRIO_FLAGS_INVALID && old != new) { - NL_SET_ERR_MSG_MOD(extack, "Changing 'flags' of a running schedule is not supported"); - return -EOPNOTSUPP; - } - - if (!taprio_flags_valid(new)) { - NL_SET_ERR_MSG_MOD(extack, "Specified 'flags' are not valid"); - return -EINVAL; - } - - return new; -} - static int taprio_change(struct Qdisc *sch, struct nlattr *opt, struct netlink_ext_ack *extack) { @@ -1852,6 +1815,7 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt, struct net_device *dev = qdisc_dev(sch); struct tc_mqprio_qopt *mqprio = NULL; unsigned long flags; + u32 taprio_flags; ktime_t start; int i, err; @@ -1863,12 +1827,28 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt, if (tb[TCA_TAPRIO_ATTR_PRIOMAP]) mqprio = nla_data(tb[TCA_TAPRIO_ATTR_PRIOMAP]); - err = taprio_new_flags(tb[TCA_TAPRIO_ATTR_FLAGS], - q->flags, extack); - if (err < 0) - return err; + /* The semantics of the 'flags' argument in relation to 'change()' + * requests, are interpreted following two rules (which are applied in + * this order): (1) an omitted 'flags' argument is interpreted as + * zero; (2) the 'flags' of a "running" taprio instance cannot be + * changed. + */ + taprio_flags = tb[TCA_TAPRIO_ATTR_FLAGS] ? nla_get_u32(tb[TCA_TAPRIO_ATTR_FLAGS]) : 0; - q->flags = err; + /* txtime-assist and full offload are mutually exclusive */ + if ((taprio_flags & TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST) && + (taprio_flags & TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD)) { + NL_SET_ERR_MSG_ATTR(extack, tb[TCA_TAPRIO_ATTR_FLAGS], + "TXTIME_ASSIST and FULL_OFFLOAD are mutually exclusive"); + return -EINVAL; + } + + if (q->flags != TAPRIO_FLAGS_INVALID && q->flags != taprio_flags) { + NL_SET_ERR_MSG_MOD(extack, + "Changing 'flags' of a running schedule is not supported"); + return -EOPNOTSUPP; + } + q->flags = taprio_flags; err = taprio_parse_mqprio_opt(dev, mqprio, extack, q->flags); if (err < 0)