On Thu, Jan 19, 2017 at 08:18:13PM -0200, Marcelo Ricardo Leitner wrote:
> 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.
You're right, I missed the socket lock in sctp_setsockopt, that covers us both
from multiple processes and bottom halves.
>
> Marcelo
>
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