Re: [PATCH 4/6] sctp multistream scheduling: extend socket API

[Vlad Yasevich <vladislav.yasevich@hp.com>]

Wei Yongjun wrote:
>> Augment SCTP socket API with a new socket option to choose and
>> configure scheduling algorithm.
>>
>> Signed-off-by: Yaogong Wang <ywang15@ncsu.edu>
>> ---
>> diff -uprN -X linux-2.6.32.8/Documentation/dontdiff
>> p3/include/net/sctp/structs.h p4/include/net/sctp/structs.h
>> --- p3/include/net/sctp/structs.h	2010-06-02 12:57:24.000000000 -0700
>> +++ p4/include/net/sctp/structs.h	2010-06-02 12:58:11.000000000 -0700
>> @@ -326,6 +326,8 @@ struct sctp_sock {
>>
>>  	/* Multistream scheduling  */
>>  	const struct sctp_sched_ops *sched_ops;
>> +	__u32 sched_priv_len;
>> +	__u16 *sched_priv;
>>   
>>  	struct sctp_initmsg initmsg;
>>  	struct sctp_rtoinfo rtoinfo;
>> @@ -1691,6 +1693,8 @@ struct sctp_association {
>>
>>  	/* Multistream scheduling  */
>>  	const struct sctp_sched_ops *sched_ops;
>> +	__u32 sched_priv_len;
>> +	__u16 *sched_priv;
>>   
> 
> I also see you add "__u16 *sched_internal;" to asoc, those are
> the sche base values, and are different between sche.
> The socket and assoc may not want to know the detail, raw data
> is enough for them, and if we want to add a new sche, we do
> not change the struct sctp_sock or struct sctp_association every
> time.

I agree.  These should probably go into sched_ops.

-vlad

> 
>>  	/* Heartbeat interval: The endpoint sends out a Heartbeat chunk to
>>  	 * the destination address every heartbeat interval. This value
>> diff -uprN -X linux-2.6.32.8/Documentation/dontdiff
>> p3/include/net/sctp/user.h p4/include/net/sctp/user.h
>> --- p3/include/net/sctp/user.h	2010-05-28 10:59:23.000000000 -0700
>> +++ p4/include/net/sctp/user.h	2010-05-28 11:54:47.000000000 -0700
>> @@ -67,6 +67,8 @@ enum sctp_optname {
>>  #define SCTP_ASSOCINFO SCTP_ASSOCINFO
>>  	SCTP_INITMSG,
>>  #define SCTP_INITMSG SCTP_INITMSG
>> +	SCTP_SCHED,
>> +#define SCTP_SCHED SCTP_SCHED
>>  	SCTP_NODELAY, 	/* Get/set nodelay option. */
>>  #define SCTP_NODELAY	SCTP_NODELAY
>>  	SCTP_AUTOCLOSE,
>> @@ -171,8 +173,22 @@ struct sctp_initmsg {
>>  	__u16 sinit_max_init_timeo;
>>  };
>>
>> +/*
>> + * SCTP Scheduling Structure (SCTP_SCHED)
>> + *
>> + *   cmsg_level    cmsg_type      cmsg_data[]
>> + *   ------------  ------------   ----------------------
>> + *   IPPROTO_SCTP  SCTP_SCHED     struct sctp_sched
>> + *
>> + */
>>  #define SCTP_SCHED_NAME_MAX	16
>>
>> +struct sctp_sched {
>> +	char  ssched_name[SCTP_SCHED_NAME_MAX];
>> +	__u32 ssched_priv_len;
>> +	__u16 ssched_priv[0];
>> +};
>> +
>>  /*
>>   * 5.2.2 SCTP Header Information Structure (SCTP_SNDRCV)
>>   *
>> diff -uprN -X linux-2.6.32.8/Documentation/dontdiff
>> p3/net/sctp/associola.c p4/net/sctp/associola.c
>> --- p3/net/sctp/associola.c	2010-06-02 12:57:06.000000000 -0700
>> +++ p4/net/sctp/associola.c	2010-06-02 12:57:57.000000000 -0700
>> @@ -187,6 +187,14 @@ static struct sctp_association *sctp_ass
>>
>>  	/* Multistream scheduling  */
>>  	asoc->sched_ops = sp->sched_ops;
>> +	asoc->sched_priv_len = sp->sched_priv_len;
>> +	if (asoc->sched_priv_len) {
>> +		asoc->sched_priv = kmalloc(asoc->sched_priv_len, gfp);
>> +		if (!asoc->sched_priv)
>> +			goto fail_init;
>> +		memcpy(asoc->sched_priv, sp->sched_priv, asoc->sched_priv_len);
>> +	} else
>> +		asoc->sched_priv = NULL;
>>
>>  	/* Allocate storage for the ssnmap after the inbound and outbound
>>  	 * streams have been negotiated during Init.
>> @@ -464,6 +472,8 @@ static void sctp_association_destroy(str
>>  {
>>  	SCTP_ASSERT(asoc->base.dead, "Assoc is not dead", return);
>>
>> +	kfree(asoc->sched_priv);
>> +
>>  	sctp_endpoint_put(asoc->ep);
>>  	sock_put(asoc->base.sk);
>>
>> diff -uprN -X linux-2.6.32.8/Documentation/dontdiff
>> p3/net/sctp/socket.c p4/net/sctp/socket.c
>> --- p3/net/sctp/socket.c	2010-05-28 12:38:09.000000000 -0700
>> +++ p4/net/sctp/socket.c	2010-05-28 12:36:37.000000000 -0700
>> @@ -2580,6 +2580,50 @@ static int sctp_setsockopt_initmsg(struc
>>  	return 0;
>>  }
>>
>> +/* Set the multistream scheduling algorithm*/
>> +static int sctp_setsockopt_sched(struct sock *sk, char __user *optval,
>> +						unsigned int optlen)
>> +{
>> +	struct sctp_sched *ssched = NULL;
>> +	struct sctp_sock *sp = sctp_sk(sk);
>> +	int ret = 0;
>> +
>> +	if (optlen < sizeof(struct sctp_sched))
>> +		return -EINVAL;
>> +
>> +	ssched = kmalloc(optlen, GFP_KERNEL);
>> +	if (!ssched)
>> +		return -ENOMEM;
>> +
>> +	if (copy_from_user(ssched, optval, optlen)) {
>> +		ret = -EFAULT;
>> +		goto out;
>> +	}
>> +
>> +	if (optlen != sizeof(struct sctp_sched) + ssched->ssched_priv_len) {
>> +		ret = -EINVAL;
>> +		goto out;
>> +	}
>> +
>> +	ret = sctp_set_sched(sk, ssched->ssched_name);
>> +	if (ret)
>> +		goto out;
>> +	sp->sched_priv_len = ssched->ssched_priv_len;
>> +	kfree(sp->sched_priv);
>> +	if (sp->sched_priv_len) {
>> +		sp->sched_priv = kmalloc(sp->sched_priv_len, GFP_KERNEL);
>> +		if (!sp->sched_priv) {
>> +			ret = -ENOMEM;
>> +			goto out;
>> +		}
>> +		memcpy(sp->sched_priv, ssched->ssched_priv, sp->sched_priv_len);
>> +	}
>> +
>> +out:
>> +	kfree(ssched);
>> +	return ret;
>> +}
>> +
>>  /*
>>   * 7.1.14 Set default send parameters (SCTP_DEFAULT_SEND_PARAM)
>>   *
>> @@ -3417,6 +3461,9 @@ SCTP_STATIC int sctp_setsockopt(struct s
>>  		retval = sctp_setsockopt_partial_delivery_point(sk, optval, optlen);
>>  		break;
>>
>> +	case SCTP_SCHED:
>> +		retval = sctp_setsockopt_sched(sk, optval, optlen);
>> +		break;
>>  	case SCTP_INITMSG:
>>  		retval = sctp_setsockopt_initmsg(sk, optval, optlen);
>>  		break;
>> @@ -3642,7 +3689,10 @@ SCTP_STATIC int sctp_init_sock(struct so
>>  	sp->initmsg.sinit_max_attempts   = sctp_max_retrans_init;
>>  	sp->initmsg.sinit_max_init_timeo = sctp_rto_max;
>>
>> +	/* Initialize default scheduling algorithm  */
>>  	sp->sched_ops = sctp_default_sched_ops;
>> +	sp->sched_priv_len = 0;
>> +	sp->sched_priv = NULL;
>>
>>  	/* Initialize default RTO related parameters.  These parameters can
>>  	 * be modified for with the SCTP_RTOINFO socket option.
>> @@ -3735,6 +3785,9 @@ SCTP_STATIC void sctp_destroy_sock(struc
>>
>>  	SCTP_DEBUG_PRINTK("sctp_destroy_sock(sk: %p)\n", sk);
>>
>> +	sctp_cleanup_sched(sk);
>> +	kfree(sctp_sk(sk)->sched_priv);
>> +
>>  	/* Release our hold on the endpoint. */
>>  	ep = sctp_sk(sk)->ep;
>>  	sctp_endpoint_free(ep);
>> @@ -4351,6 +4404,35 @@ static int sctp_getsockopt_initmsg(struc
>>  	return 0;
>>  }
>>
>> +/* Get the multistream scheduling algorithm*/
>> +static int sctp_getsockopt_sched(struct sock *sk, int len, char __user *optval,
>> +							int __user *optlen)
>> +{
>> +	struct sctp_sched *ssched;
>> +	int sz = sizeof(struct sctp_sched) + sctp_sk(sk)->sched_priv_len;
>> +	int ret = 0;
>> +
>> +	if (len < sz)
>> +		return -EINVAL;
>> +	if (put_user(sz, optlen))
>> +		return -EFAULT;
>> +
>> +	ssched = kmalloc(sz, GFP_KERNEL);
>> +	if (!ssched)
>> +		return -EFAULT;
>> +	memcpy(ssched->ssched_name, sctp_sk(sk)->sched_ops->name,
>> +					SCTP_SCHED_NAME_MAX);
>> +	ssched->ssched_priv_len = sctp_sk(sk)->sched_priv_len;
>> +	memcpy(ssched->ssched_priv, sctp_sk(sk)->sched_priv,
>> +					ssched->ssched_priv_len);
>> +
>> +	if (copy_to_user(optval, ssched, sz))
>> +		ret = -EFAULT;
>> +
>> +	kfree(ssched);
>> +	return ret;
>> +}
>> +
>>  static int sctp_getsockopt_peer_addrs_num_old(struct sock *sk, int len,
>>  					      char __user *optval,
>>  					      int __user *optlen)
>> @@ -5605,6 +5687,9 @@ SCTP_STATIC int sctp_getsockopt(struct s
>>  	case SCTP_INITMSG:
>>  		retval = sctp_getsockopt_initmsg(sk, len, optval, optlen);
>>  		break;
>> +	case SCTP_SCHED:
>> +		retval = sctp_getsockopt_sched(sk, len, optval, optlen);
>> +		break;
>>  	case SCTP_GET_PEER_ADDRS_NUM_OLD:
>>  		retval = sctp_getsockopt_peer_addrs_num_old(sk, len, optval,
>>  							    optlen);
>> --
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>>   
>