switch sctp_user_addto_chunk() and sctp_datamsg_from_user() to passing iov_iter

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

3 files changed, 16 insertions, 14 deletions

diff --git a/net/sctp/chunk.c b/net/sctp/chunk.c
index 158701da2d31..a3380917f197 100644
--- a/net/sctp/chunk.c
+++ b/net/sctp/chunk.c
@@ -164,7 +164,7 @@ static void sctp_datamsg_assign(struct sctp_datamsg *msg, struct sctp_chunk *chu
  */
 struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
                                             struct sctp_sndrcvinfo *sinfo,
-                                            struct msghdr *msgh, int msg_len)
+                                            struct iov_iter *from)
 {
         int max, whole, i, offset, over, err;
         int len, first_len;
@@ -172,6 +172,7 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
         struct sctp_chunk *chunk;
         struct sctp_datamsg *msg;
         struct list_head *pos, *temp;
+        size_t msg_len = iov_iter_count(from);
         __u8 frag;
 
         msg = sctp_datamsg_new(GFP_KERNEL);
@@ -279,12 +280,10 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
                         goto errout;
                 }
 
-                err = sctp_user_addto_chunk(chunk, offset, len, msgh->msg_iov);
+                err = sctp_user_addto_chunk(chunk, len, from);
                 if (err < 0)
                         goto errout_chunk_free;
 
-                offset += len;
-
                 /* Put the chunk->skb back into the form expected by send.  */
                 __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
                            - (__u8 *)chunk->skb->data);
@@ -317,7 +316,7 @@ struct sctp_datamsg *sctp_datamsg_from_user(struct sctp_association *asoc,
                         goto errout;
                 }
 
-                err = sctp_user_addto_chunk(chunk, offset, over, msgh->msg_iov);
+                err = sctp_user_addto_chunk(chunk, over, from);
 
                 /* Put the chunk->skb back into the form expected by send.  */
                 __skb_pull(chunk->skb, (__u8 *)chunk->chunk_hdr
diff --git a/net/sctp/sm_make_chunk.c b/net/sctp/sm_make_chunk.c
index e49bccebb0cc..e49e231cef52 100644
--- a/net/sctp/sm_make_chunk.c
+++ b/net/sctp/sm_make_chunk.c
@@ -1491,26 +1491,26 @@ static void *sctp_addto_chunk_fixed(struct sctp_chunk *chunk,
  * chunk is not big enough.
  * Returns a kernel err value.
  */
-int sctp_user_addto_chunk(struct sctp_chunk *chunk, int off, int len,
-                          struct iovec *data)
+int sctp_user_addto_chunk(struct sctp_chunk *chunk, int len,
+                          struct iov_iter *from)
 {
-        __u8 *target;
-        int err = 0;
+        void *target;
+        ssize_t copied;
 
         /* Make room in chunk for data.  */
         target = skb_put(chunk->skb, len);
 
         /* Copy data (whole iovec) into chunk */
-        if ((err = memcpy_fromiovecend(target, data, off, len)))
-                goto out;
+        copied = copy_from_iter(target, len, from);
+        if (copied != len)
+                return -EFAULT;
 
         /* Adjust the chunk length field.  */
         chunk->chunk_hdr->length =
                 htons(ntohs(chunk->chunk_hdr->length) + len);
         chunk->chunk_end = skb_tail_pointer(chunk->skb);
 
-out:
-        return err;
+        return 0;
 }
 
 /* Helper function to assign a TSN if needed.  This assumes that both
diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index 85e0b653edd7..0397ac9fd98c 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -1609,6 +1609,9 @@ static int sctp_sendmsg(struct kiocb *iocb, struct sock *sk,
         __u16 sinfo_flags = 0;
         long timeo;
         int err;
+        struct iov_iter from;
+
+        iov_iter_init(&from, WRITE, msg->msg_iov, msg->msg_iovlen, msg_len);
 
         err = 0;
         sp = sctp_sk(sk);
@@ -1947,7 +1950,7 @@ static int sctp_sendmsg(struct kiocb *iocb, struct sock *sk,
         }
 
         /* Break the message into multiple chunks of maximum size. */
-        datamsg = sctp_datamsg_from_user(asoc, sinfo, msg, msg_len);
+        datamsg = sctp_datamsg_from_user(asoc, sinfo, &from);
         if (IS_ERR(datamsg)) {
                 err = PTR_ERR(datamsg);
                 goto out_free;