sctp: factor out stream->out allocation

There is 1 place allocating it and 2 other reallocating. Move such
procedures to a common function.

Tested-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sctp/stream.c b/net/sctp/stream.c
index 1afa9555808390d5fc736727422d9700a3855613..6d0e997d301f89e165367106c02e82f8a6c3a877 100644 (file)
--- a/net/sctp/stream.c
+++ b/net/sctp/stream.c
@@ -35,6 +35,30 @@
 #include <net/sctp/sctp.h>
 #include <net/sctp/sm.h>
 
+static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt,
+                                gfp_t gfp)
+{
+       struct sctp_stream_out *out;
+
+       out = kmalloc_array(outcnt, sizeof(*out), gfp);
+       if (!out)
+               return -ENOMEM;
+
+       if (stream->out) {
+               memcpy(out, stream->out, min(outcnt, stream->outcnt) *
+                                        sizeof(*out));
+               kfree(stream->out);
+       }
+
+       if (outcnt > stream->outcnt)
+               memset(out + stream->outcnt, 0,
+                      (outcnt - stream->outcnt) * sizeof(*out));
+
+       stream->out = out;
+
+       return 0;
+}
+
 int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
                     gfp_t gfp)
 {
@@ -48,11 +72,9 @@ int sctp_stream_init(struct sctp_stream *stream, __u16 outcnt, __u16 incnt,
        if (outcnt == stream->outcnt)
                goto in;
 
-       kfree(stream->out);
-
-       stream->out = kcalloc(outcnt, sizeof(*stream->out), gfp);
-       if (!stream->out)
-               return -ENOMEM;
+       i = sctp_stream_alloc_out(stream, outcnt, gfp);
+       if (i)
+               return i;
 
        stream->outcnt = outcnt;
        for (i = 0; i < stream->outcnt; i++)
@@ -276,15 +298,9 @@ int sctp_send_add_streams(struct sctp_association *asoc,
        }
 
        if (out) {
-               struct sctp_stream_out *streamout;
-
-               streamout = krealloc(stream->out, outcnt * sizeof(*streamout),
-                                    GFP_KERNEL);
-               if (!streamout)
+               retval = sctp_stream_alloc_out(stream, outcnt, GFP_KERNEL);
+               if (retval)
                        goto out;
-
-               memset(streamout + stream->outcnt, 0, out * sizeof(*streamout));
-               stream->out = streamout;
        }
 
        chunk = sctp_make_strreset_addstrm(asoc, out, in);
@@ -682,10 +698,10 @@ struct sctp_chunk *sctp_process_strreset_addstrm_in(
        struct sctp_strreset_addstrm *addstrm = param.v;
        struct sctp_stream *stream = &asoc->stream;
        __u32 result = SCTP_STRRESET_DENIED;
-       struct sctp_stream_out *streamout;
        struct sctp_chunk *chunk = NULL;
        __u32 request_seq, outcnt;
        __u16 out, i;
+       int ret;
 
        request_seq = ntohl(addstrm->request_seq);
        if (TSN_lt(asoc->strreset_inseq, request_seq) ||
@@ -714,14 +730,10 @@ struct sctp_chunk *sctp_process_strreset_addstrm_in(
        if (!out || outcnt > SCTP_MAX_STREAM)
                goto out;
 
-       streamout = krealloc(stream->out, outcnt * sizeof(*streamout),
-                            GFP_ATOMIC);
-       if (!streamout)
+       ret = sctp_stream_alloc_out(stream, outcnt, GFP_ATOMIC);
+       if (ret)
                goto out;
 
-       memset(streamout + stream->outcnt, 0, out * sizeof(*streamout));
-       stream->out = streamout;
-
        chunk = sctp_make_strreset_addstrm(asoc, out, 0);
        if (!chunk)
                goto out;