[ofw] [IPoIB, IPoIB_CM] Bugfix for UDP packets

[Alex Estrin]

Hello,

Would you please clarify if this is the case when OS fragments large send packet to interface-MTU-size chunks?

Thanks,
Alex.


> -----Original Message-----
> From: Alex Naslednikov [mailto:xalex at mellanox.co.il] 
> Sent: Sunday, January 18, 2009 9:37 AM
> To: ofw at lists.openfabrics.org
> Cc: Tzachi Dar; Alex Estrin
> Subject: [ofw] [IPoIB, IPoIB_CM] Bugfix for UDP packets
> 
> Several test were failed on sending UDP packets with MTU-like sizes.
> Fragmented UDP packets do not contain UDP header, except the 
> first one.
> So, appropriate check was inserted.
>  
> This bug was shown rarely (only when the last fragment was 
> less than 8 bytes), because the following check always worked 
> (by mistake):
>  
> if( (p_udp_hdr->src_port != DHCP_PORT_CLIENT ||
>   p_udp_hdr->dst_port != DHCP_PORT_SERVER) &&
>   (p_udp_hdr->src_port != DHCP_PORT_SERVER ||
>   p_udp_hdr->dst_port != DHCP_PORT_CLIENT) )
>  {
>   /* Not a DHCP packet. */
>   return NDIS_STATUS_PENDING;
>  }
>  
> Index: ipoib_port.c
> ===================================================================
> --- ipoib_port.c (revision 3752)
> +++ ipoib_port.c (working copy)
> @@ -3763,6 +3763,15 @@
>    p_udp_hdr = (udp_hdr_t*)GetIpPayloadPtr(p_ip_hdr);
>   }
>   /* Get the UDP header and check the destination port numbers. */
> + 
> + if (p_ip_hdr->offset > 0) {
> +  /* This is a fragmented part of UDP packet
> +   * Only first packet will contain UDP header in such case
> +   * So, return if offset > 0
> +   */
> +   return NDIS_STATUS_PENDING;
> + }
> +   
>   if( buf_len < sizeof(udp_hdr_t) )
>   {
>    IPOIB_PRINT_EXIT( TRACE_LEVEL_ERROR, IPOIB_DBG_ERROR
>