papi: Use CMSG_SPACE for sizing ancillary buffer space
CMSG_LEN provides the length required to store an ancillary item, but it
does not consider padding. RFC 3542 requires portable applications to
use CMSG_SPACE(), this is documented in the python API:
https://docs.python.org/3/library/socket.html#socket.CMSG_LEN
Type: improvement
Change-Id: I0eab470585f2f39bea38639db95d6b0e047d2cff
Signed-off-by: Tom Jones <thj@freebsd.org>
diff --git a/src/vpp-api/python/vpp_papi/vpp_stats.py b/src/vpp-api/python/vpp_papi/vpp_stats.py
index 4a342b6..8cbe737 100755
--- a/src/vpp-api/python/vpp_papi/vpp_stats.py
+++ b/src/vpp-api/python/vpp_papi/vpp_stats.py
@@ -54,7 +54,7 @@
def recv_fd(sock):
"""Get file descriptor for memory map"""
fds = array.array("i") # Array of ints
- _, ancdata, _, _ = sock.recvmsg(0, socket.CMSG_LEN(4))
+ _, ancdata, _, _ = sock.recvmsg(0, socket.CMSG_SPACE(4))
for cmsg_level, cmsg_type, cmsg_data in ancdata:
if cmsg_level == socket.SOL_SOCKET and cmsg_type == socket.SCM_RIGHTS:
fds.frombytes(cmsg_data[: len(cmsg_data) - (len(cmsg_data) % fds.itemsize)])