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NAME | SYNOPSIS | DESCRIPTION | RETURN VALUE | SEE ALSO | AUTHOR | COLOPHON |
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UMAD_RECV(3) OpenIB Programmer's Manual UMAD_RECV(3)
umad_recv - receive umad
#include <infiniband/umad.h>
int umad_recv(int portid, void *umad, int *length, int timeout_ms);
umad_recv() waits up to timeout_ms milliseconds for an incoming
MAD message to be received from the port specified by portid.
A MAD "message" consists of a single MAD packet or a coalesced
multipacket RMPP transmission. In the RMPP case the header of
the first RMPP packet is returned as the header of the buffer and
the buffer data contains the coalesced data section of each
subsequent RMPP MAD packet within the transmission. Thus all the
RMPP headers except the first are not copied to user space from
the kernel.
The message is copied to the umad buffer if there is sufficient
room and the received length is indicated. If the buffer is not
large enough, the size of the umad buffer needed is returned in
length. A negative timeout_ms makes the function block until a
packet is received. A timeout_ms parameter of zero indicates a
non blocking read.
Note length is a pointer to the length of the data portion of the
umad buffer. This means that umad must point to a buffer at
least umad_size() + *length bytes long.
Note also that *length must be >= 256 bytes. This length allows
for at least a single MAD packet to be returned.
umad_recv() on success return the agentid; on error, errno is set
and a negative value is returned as follows:
-EINVAL invalid port handle or agentid or *length is less
than the minimum supported
-EIO receive operation failed
-EWOULDBLOCK non blocking read can't be fulfilled
-ENOSPC The provided buffer is not long enough for the
complete message.
umad_poll(3)
Hal Rosenstock <halr@voltaire.com>
This page is part of the rdma-core (RDMA Core Userspace Libraries
and Daemons) project. Information about the project can be found
at ⟨https://github.com/linux-rdma/rdma-core⟩. If you have a bug
report for this manual page, send it to
linux-rdma@vger.kernel.org. This page was obtained from the
project's upstream Git repository
⟨https://github.com/linux-rdma/rdma-core.git⟩ on 2024-06-14. (At
that time, the date of the most recent commit that was found in
the repository was 2024-06-10.) If you discover any rendering
problems in this HTML version of the page, or you believe there
is a better or more up-to-date source for the page, or you have
corrections or improvements to the information in this COLOPHON
(which is not part of the original manual page), send a mail to
man-pages@man7.org
OpenIB May 11, 2007 UMAD_RECV(3)
Pages that refer to this page: umad_poll(3)
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HTML rendering created 2024-06-26 by Michael Kerrisk, author of The Linux Programming Interface. For details of in-depth Linux/UNIX system programming training courses that I teach, look here. Hosting by jambit GmbH. |
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