Commit 8d2a6935 authored by Xin Long's avatar Xin Long Committed by David S. Miller
Browse files

sctp: add SCTP_EXPOSE_POTENTIALLY_FAILED_STATE sockopt 



This is a sockopt defined in section 7.3 of rfc7829: "Exposing
the Potentially Failed Path State", by which users can change
pf_expose per sock and asoc.

The new sockopt SCTP_EXPOSE_POTENTIALLY_FAILED_STATE is also
known as SCTP_EXPOSE_PF_STATE for short.

v2->v3:
  - return -EINVAL if params.assoc_value > SCTP_PF_EXPOSE_MAX.
  - define SCTP_EXPOSE_PF_STATE SCTP_EXPOSE_POTENTIALLY_FAILED_STATE.
v3->v4:
  - improve changelog.

Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
Acked-by: default avatarNeil Horman <nhorman@tuxdriver.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 768e1518

include/uapi/linux/sctp.h

+2 −0
Original line number Diff line number Diff line
@@ -137,6 +137,8 @@ typedef __s32 sctp_assoc_t; 
#define SCTP_ASCONF_SUPPORTED	128

#define SCTP_AUTH_SUPPORTED	129

#define SCTP_ECN_SUPPORTED	130

#define SCTP_EXPOSE_POTENTIALLY_FAILED_STATE	131

#define SCTP_EXPOSE_PF_STATE	SCTP_EXPOSE_POTENTIALLY_FAILED_STATE



/* PR-SCTP policies */

#define SCTP_PR_SCTP_NONE	0x0000

net/sctp/socket.c

+79 −0
Original line number Diff line number Diff line
@@ -4589,6 +4589,40 @@ out: 
	return retval;

}



static int sctp_setsockopt_pf_expose(struct sock *sk,

				     char __user *optval,

				     unsigned int optlen)

{

	struct sctp_assoc_value params;

	struct sctp_association *asoc;

	int retval = -EINVAL;



	if (optlen != sizeof(params))

		goto out;



	if (copy_from_user(&params, optval, optlen)) {

		retval = -EFAULT;

		goto out;

	}



	if (params.assoc_value > SCTP_PF_EXPOSE_MAX)

		goto out;



	asoc = sctp_id2assoc(sk, params.assoc_id);

	if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&

	    sctp_style(sk, UDP))

		goto out;



	if (asoc)

		asoc->pf_expose = params.assoc_value;

	else

		sctp_sk(sk)->pf_expose = params.assoc_value;

	retval = 0;



out:

	return retval;

}



/* API 6.2 setsockopt(), getsockopt()

 *

 * Applications use setsockopt() and getsockopt() to set or retrieve
@@ -4798,6 +4832,9 @@ static int sctp_setsockopt(struct sock *sk, int level, int optname, 
	case SCTP_ECN_SUPPORTED:

		retval = sctp_setsockopt_ecn_supported(sk, optval, optlen);

		break;

	case SCTP_EXPOSE_POTENTIALLY_FAILED_STATE:

		retval = sctp_setsockopt_pf_expose(sk, optval, optlen);

		break;

	default:

		retval = -ENOPROTOOPT;

		break;
@@ -7909,6 +7946,45 @@ out: 
	return retval;

}



static int sctp_getsockopt_pf_expose(struct sock *sk, int len,

				     char __user *optval,

				     int __user *optlen)

{

	struct sctp_assoc_value params;

	struct sctp_association *asoc;

	int retval = -EFAULT;



	if (len < sizeof(params)) {

		retval = -EINVAL;

		goto out;

	}



	len = sizeof(params);

	if (copy_from_user(&params, optval, len))

		goto out;



	asoc = sctp_id2assoc(sk, params.assoc_id);

	if (!asoc && params.assoc_id != SCTP_FUTURE_ASSOC &&

	    sctp_style(sk, UDP)) {

		retval = -EINVAL;

		goto out;

	}



	params.assoc_value = asoc ? asoc->pf_expose

				  : sctp_sk(sk)->pf_expose;



	if (put_user(len, optlen))

		goto out;



	if (copy_to_user(optval, &params, len))

		goto out;



	retval = 0;



out:

	return retval;

}



static int sctp_getsockopt(struct sock *sk, int level, int optname,

			   char __user *optval, int __user *optlen)

{
@@ -8121,6 +8197,9 @@ static int sctp_getsockopt(struct sock *sk, int level, int optname, 
	case SCTP_ECN_SUPPORTED:

		retval = sctp_getsockopt_ecn_supported(sk, len, optval, optlen);

		break;

	case SCTP_EXPOSE_POTENTIALLY_FAILED_STATE:

		retval = sctp_getsockopt_pf_expose(sk, len, optval, optlen);

		break;

	default:

		retval = -ENOPROTOOPT;

		break;

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