From: Patrick McHardy <kaber@trash•net>
To: Corey Hickey <bugfood-ml@fatooh•org>
Cc: netdev@vger•kernel.org
Subject: Re: [PATCH 10/10] Use nested compat attributes to pass parameters.
Date: Mon, 01 Oct 2007 15:54:38 +0200 [thread overview]
Message-ID: <4700FC1E.9040309@trash.net> (raw)
In-Reply-To: <11910199782593-git-send-email-bugfood-ml@fatooh.org>
Corey Hickey wrote:
> This fixes the ambiguity between, for example:
> tc qdisc change ... perturb 0
> tc qdisc change ...
>
> Without this patch, there is no way for SFQ to differentiate between
> a parameter specified to be 0 and a parameter that was omitted.
>
> diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
> index 170fd37..36197f6 100644
> --- a/net/sched/sch_sfq.c
> +++ b/net/sched/sch_sfq.c
> @@ -428,25 +428,31 @@ sfq_q_init(struct sfq_sched_data *q, struct rtattr *opt)
> * the previous values (sfq_change). So, overwrite the parameters as
> * specified. */
> if (opt) {
> - struct tc_sfq_qopt *ctl = RTA_DATA(opt);
> -
> - if (opt->rta_len < RTA_LENGTH(sizeof(*ctl)))
> - return -EINVAL;
> -
> - if (ctl->quantum)
> - q->quantum = ctl->quantum;
> - if (ctl->perturb_period)
> - q->perturb_period = ctl->perturb_period;
> - if (ctl->divisor)
> - q->hash_divisor = ctl->divisor;
> - if (ctl->flows)
> - q->depth = ctl->flows;
> - if (ctl->limit)
> - q->limit = ctl->limit;
> -
> + struct tc_sfq_qopt *ctl;
> + struct rtattr *tb[TCA_SFQ_MAX];
> +
> + if (rtattr_parse_nested_compat(tb, TCA_SFQ_MAX, opt, ctl,
> + sizeof(*ctl)))
> + goto rtattr_failure;
> +
> +#define GET_PARAM(dst, nest, compat) do { \
> + struct rtattr *rta = tb[(nest) - 1]; \
> + if (rta) \
> + (dst) = RTA_GET_U32(rta); \
> + else if ((compat)) \
> + (dst) = (compat); \
> +} while (0)
An inline function and a comment why this is done would increase
readability.
> +
> + GET_PARAM(q->quantum, TCA_SFQ_QUANTUM, ctl->quantum);
> + GET_PARAM(q->perturb_period, TCA_SFQ_PERTURB,
> + ctl->perturb_period);
> + GET_PARAM(q->hash_divisor, TCA_SFQ_DIVISOR, ctl->divisor);
> + GET_PARAM(q->depth, TCA_SFQ_FLOWS, ctl->flows);
> + GET_PARAM(q->limit, TCA_SFQ_LIMIT, ctl->limit);
> +
> if (q->perturb_period > SFQ_MAX_PERTURB ||
> q->depth > SFQ_MAX_DEPTH)
> - return -EINVAL;
> + goto rtattr_failure;
> }
> q->limit = min_t(u32, q->limit, q->depth - 2);
> q->tail = q->depth;
> @@ -482,6 +488,8 @@ sfq_q_init(struct sfq_sched_data *q, struct rtattr *opt)
> for (i=0; i < q->depth; i++)
> sfq_link(q, i);
> return 0;
> +rtattr_failure:
> + return -EINVAL;
> err_case:
> sfq_q_destroy(q);
> return -ENOBUFS;
> @@ -559,17 +567,26 @@ static int sfq_dump(struct Qdisc *sch, struct sk_buff *skb)
> {
> struct sfq_sched_data *q = qdisc_priv(sch);
> unsigned char *b = skb_tail_pointer(skb);
> + struct rtattr *nest;
> struct tc_sfq_qopt opt;
>
> opt.quantum = q->quantum;
> opt.perturb_period = q->perturb_period;
> -
> opt.limit = q->limit;
> opt.divisor = q->hash_divisor;
> opt.flows = q->depth;
>
> + nest = RTA_NEST_COMPAT(skb, TCA_OPTIONS, sizeof(opt), &opt);
> +
> + RTA_PUT_U32(skb, TCA_SFQ_QUANTUM, q->quantum);
> + RTA_PUT_U32(skb, TCA_SFQ_PERTURB, q->perturb_period);
> + RTA_PUT_U32(skb, TCA_SFQ_LIMIT, q->limit);
> + RTA_PUT_U32(skb, TCA_SFQ_DIVISOR, q->hash_divisor);
> + RTA_PUT_U32(skb, TCA_SFQ_FLOWS, q->depth);
> RTA_PUT(skb, TCA_OPTIONS, sizeof(opt), &opt);
This is wrong, RTA_NEST_COMPAT already dumps the structure.
>
> + RTA_NEST_COMPAT_END(skb, nest);
> +
> return skb->len;
>
> rtattr_failure:
next prev parent reply other threads:[~2007-10-01 13:55 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-09-28 22:52 SFQ: backport some features from ESFQ (try 4) Corey Hickey
2007-09-28 22:52 ` [PATCH 01/10] Preparatory refactoring part 1 Corey Hickey
2007-10-01 13:25 ` Patrick McHardy
2007-10-01 20:46 ` Corey Hickey
2007-10-02 3:17 ` Patrick McHardy
2007-09-28 22:52 ` [PATCH 02/10] Preparatory refactoring part 2 Corey Hickey
2007-10-01 13:33 ` Patrick McHardy
2007-10-01 20:46 ` Corey Hickey
2007-10-02 3:19 ` Patrick McHardy
2007-09-28 22:52 ` [PATCH 03/10] Move two functions Corey Hickey
2007-10-01 13:27 ` Patrick McHardy
2007-10-01 20:46 ` Corey Hickey
2007-09-28 22:52 ` [PATCH 04/10] Make "depth" (number of queues) user-configurable: Corey Hickey
2007-09-28 22:52 ` [PATCH 05/10] Add divisor Corey Hickey
2007-10-01 13:38 ` Patrick McHardy
2007-10-01 20:47 ` Corey Hickey
2007-09-28 22:52 ` [PATCH 06/10] Make qdisc changeable Corey Hickey
2007-10-01 13:43 ` Patrick McHardy
2007-10-01 20:47 ` Corey Hickey
2007-09-28 22:52 ` [PATCH 07/10] Remove comments about hardcoded values Corey Hickey
2007-09-28 22:52 ` [PATCH 08/10] Multiply perturb_period by HZ when used rather than when assigned Corey Hickey
2007-09-28 22:52 ` [PATCH 09/10] Change perturb_period to unsigned Corey Hickey
2007-10-01 13:45 ` Patrick McHardy
2007-10-01 20:47 ` Corey Hickey
2007-09-28 22:52 ` [PATCH 10/10] Use nested compat attributes to pass parameters Corey Hickey
2007-10-01 13:54 ` Patrick McHardy [this message]
2007-10-01 20:47 ` Corey Hickey
2007-10-02 3:21 ` Patrick McHardy
2007-09-28 22:54 ` sfq Corey Hickey
2007-09-28 22:57 ` sfq (iproute2 patches) Corey Hickey
2007-09-28 22:54 ` [PATCH 1/3] SFQ: Support changing depth and divisor Corey Hickey
2007-09-28 22:54 ` [PATCH 2/3] Change perturb_period to unsigned Corey Hickey
2007-09-28 22:54 ` [PATCH 3/3] Use nested compat attributes for passing parameters to the kernel Corey Hickey
2007-09-29 15:38 ` SFQ: backport some features from ESFQ (try 4) Patrick McHardy
2007-09-29 17:36 ` Corey Hickey
-- strict thread matches above, loose matches on Subject: below --
2007-08-25 22:26 [PATCH 00/10] SFQ: backport some features from ESFQ (try 3) Corey Hickey
2007-08-25 22:27 ` [PATCH 10/10] Use nested compat attributes to pass parameters Corey Hickey
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