CODEWITHSUNDEEP
clinuxudp
barbaros
barbaros

Reputation: 49

How can I clear UDP buffer without recvfrom?

I have an embedded linux project. And it gets data via UDP to static char array from UDP buffer. This static array's size is 20000 bytes. I want to ignore UDB messages that exceed this size. But when comes bigger data, it stays always in UDP buffer since it is not read with recvfrom. Is there any way to clear this bigger data in UDP buffer?

Upvotes: 0

Views: 1550

Answers (1)

Steffen Ullrich
Steffen Ullrich

Reputation: 123320

One cannot discard the data from the socket buffer without reading. But one can read these large datagrams even when having a smaller buffer - it will simply discard anything which does not fit into the given buffer. To find out if the datagram was too large use the MSG_TRUNC flag so that it will provide the original length of the packet. If this indicates an oversized packet just discard it and continue with the next packet.

Upvotes: 2

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