Add MSG_PEEK support to pflocal

* libpipe/pq.h (packet_peek): Declare new function.
* libpipe/pq.c (packet_read): Move code to new `packet_fetch' function, call it
with `remove' set to 1.
(packet_fetch): New function with code from `packet_read', but do not remove
data if `remove' is 0.
(packet_peek): New function, calls `packet_fetch' with `remove' set to 0.
* libpipe/dgram.c (dgram_read): When MSG_PEEK is in *flags, do not dequeue
and only peek data.
* libpipe/seqpack.c (seqpack_read): Likewise.
* libpipe/stream.c (stream_read): Likewise.
* pflocal/socket.c (S_socket_recv): Pass MSG_PEEK flag to libpipe.

1 files changed, 11 insertions, 2 deletions

diff --git a/libpipe/stream.c b/libpipe/stream.c
index 8eb90435..671907e7 100644
--- a/libpipe/stream.c
+++ b/libpipe/stream.c
@@ -56,8 +56,17 @@ static error_t
 stream_read (struct packet *packet, int *dequeue, unsigned *flags,
 	     char **data, size_t *data_len, size_t amount)
 {
-  error_t err = packet_read (packet, data, data_len, amount);
-  *dequeue = (packet_readable (packet) == 0);
+  error_t err;
+  if (flags && *flags & MSG_PEEK)
+    {
+      err = packet_peek (packet, data, data_len, amount);
+      *dequeue = 0;
+    }
+  else
+    {
+      err = packet_read (packet, data, data_len, amount);
+      *dequeue = (packet_readable (packet) == 0);
+    }
   return err;
 }