[lwip-devel] MSG_WAITALL socket recv flag needed

[Sebastian Paluch]

Hello,

 

I need MSG_WAITALL flag for lwip_recvfrom function. I don’t see this in latest CVS head revision and probably this will not be there before 1.4 release, so I have tried with something like this:

 

Line 546:

    if (netconn_type(sock->conn) == NETCONN_TCP) {

      LWIP_ASSERT("invalid copylen, len would underflow", len >= copylen);

      len -= copylen;

      if ( (len <= 0) ||

           (((flags & MSG_WAITALL)==0) && ((buf->p->flags & PBUF_FLAG_PUSH) || (sock->rcvevent <= 0))) ||

           ((flags & MSG_PEEK)!=0)) {

        done = 1;

      }

    } else {

      done = 1;

    }

 

I this solution, the receive request will complete only when one of the following events occurs:

·         The buffer supplied by the caller is completely full.

·         The connection has been closed.

·         The request has been canceled or an error occurred.

 

In case of conflicts with MSG_DONTWAIT or O_NONBLOCK, the MSG_WAITALL would be silently ignored.

 

I wonder if this covers everything and I can go further with this? I would also like to know if it would be possible to have MSG_WAITALL flag in official release?

 

Thanks

Pozdrawiam/Best regards/Mit freundlichen Grüßen

Sebastian Paluch
Senior Embedded SW Engineer
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