On Thu, Jan 19, 2017 at 03:17:18PM -0500, Neil Horman wrote:
> On Fri, Jan 20, 2017 at 01:19:14AM +0800, Xin Long wrote:
> > This patch is to implement Sender-Side Procedures for the Add
> > Outgoing and Incoming Streams Request Parameter described in
> > rfc6525 section 5.1.5-5.1.6.
> >
> > It is also to add sockopt SCTP_ADD_STREAMS in rfc6525 section
> > 6.3.4 for users.
> >
> > Signed-off-by: Xin Long <lucien....@gmail.com>
> > ---
> > include/net/sctp/sctp.h | 2 +
> > include/uapi/linux/sctp.h | 7 ++++
> > net/sctp/socket.c | 29 ++++++++++++++
> > net/sctp/stream.c | 99
> > +++++++++++++++++++++++++++++++++++++++++++++++
> > 4 files changed, 137 insertions(+)
> >
> > diff --git a/include/net/sctp/sctp.h b/include/net/sctp/sctp.h
> > index b93820f..68ee1a6 100644
> > --- a/include/net/sctp/sctp.h
> > +++ b/include/net/sctp/sctp.h
> > @@ -199,6 +199,8 @@ int sctp_offload_init(void);
> > int sctp_send_reset_streams(struct sctp_association *asoc,
> > struct sctp_reset_streams *params);
> > int sctp_send_reset_assoc(struct sctp_association *asoc);
> > +int sctp_send_add_streams(struct sctp_association *asoc,
> > + struct sctp_add_streams *params);
> >
> > /*
> > * Module global variables
> > diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
> > index c0bd8c3..a91a9cc 100644
> > --- a/include/uapi/linux/sctp.h
> > +++ b/include/uapi/linux/sctp.h
> > @@ -118,6 +118,7 @@ typedef __s32 sctp_assoc_t;
> > #define SCTP_ENABLE_STREAM_RESET 118
> > #define SCTP_RESET_STREAMS 119
> > #define SCTP_RESET_ASSOC 120
> > +#define SCTP_ADD_STREAMS 121
> >
> > /* PR-SCTP policies */
> > #define SCTP_PR_SCTP_NONE 0x0000
> > @@ -1027,4 +1028,10 @@ struct sctp_reset_streams {
> > uint16_t srs_stream_list[]; /* list if srs_num_streams is not 0 */
> > };
> >
> > +struct sctp_add_streams {
> > + sctp_assoc_t sas_assoc_id;
> > + uint16_t sas_instrms;
> > + uint16_t sas_outstrms;
> > +};
> > +
> > #endif /* _UAPI_SCTP_H */
> > diff --git a/net/sctp/socket.c b/net/sctp/socket.c
> > index 2c5c9ca..ae0a99e 100644
> > --- a/net/sctp/socket.c
> > +++ b/net/sctp/socket.c
> > @@ -3838,6 +3838,32 @@ static int sctp_setsockopt_reset_assoc(struct sock
> > *sk,
> > return retval;
> > }
> >
> > +static int sctp_setsockopt_add_streams(struct sock *sk,
> > + char __user *optval,
> > + unsigned int optlen)
> > +{
> you are going to need to provide some locking here or in
> sctp_send_add_streams.
> By replacing the in/out streams pointer you run the risk of multiple callers
> modifying the pointers in parallel, or in the sctp state machine reading it
> while you do.
There can't be multiple callers here because the socket is locked before
calling this function, in sctp_setsockopt().
I also don't see how a BH handler, timers or sleeping call (recvmsg)
could trip on this.
Marcelo
