[PATCH] networking: Increase _SYS_MBUF_LEGACY_MSIZE to 256 to match FreeBSD

[Hesham Almatary]

I am not gonna push this patch. I have only tried to run loopback and
telnetd on rv64. Even though loopback doesn't make RTEMS exit with a
failure, but the scn output doesn't look right (compared to riscv32).
telnetd scn is identical and succeed on both, but I guess that's just
luck. I am not planning to debug/test further networking libtests with
the legacy stack.

Chris, I believe all the patches I submitted can wait after the
release. We can ignore this one.


On Fri, 8 May 2020 at 05:57, Sebastian Huber
<sebastian.huber at embedded-brains.de> wrote:
>
>
> On 08/05/2020 06:48, Hesham Almatary wrote:
> > Hello Chris,
> >
> > Currently sample/loopback.exe fails on risc64 with that error:
> >
> > *** BEGIN OF TEST LOOPBACK ***
> > *** TEST VERSION: 5.0.0.e78c0806cbbf0c9fae5c8c355ea81636b704f908
> > *** TEST STATE: EXPECTED_PASS
> > *** TEST BUILD: RTEMS_NETWORKING RTEMS_POSIX_API
> > *** TEST TOOLS: 9.3.0 20200312 (RTEMS 5, RSB 5 (1011d5f76851), Newlib 7947581)
> > "Network" initializing!
> > "Network" initialized!
> > Try running client with no server present.
> > Should fail with `connection refused'.
> > Connect to server.
> > tcphdr too big
> > *** FATAL ***
> > fatal source: 11 (RTEMS_FATAL_SOURCE_PANIC)
> > fatal code: 2147715424 (0x80038960)
> > RTEMS version: 5.0.0.e78c0806cbbf0c9fae5c8c355ea81636b704f908
> > RTEMS tools: 9.3.0 20200312 (RTEMS 5, RSB 5 (1011d5f76851), Newlib 7947581)
> > executing thread ID: 0x08a010001
> > executing thread name: UI1
> >
> >
> > The "tcphdr too big" error is at
> > cpukit/libnetworking/netinet/tcp_output.c:458, failing that check:
> >> if (max_linkhdr + hdrlen > MHLEN)
> >>   panic("tcphdr too big");
> > On riscv64:
> > hdrlen = 76
> > max_linkhdr = 16
> > optlen = 20
> > sizeof (struct tcpiphdr) = 56
> > MHLEN = 72
>
> The problem is probably this:
>
> /*
>   * Overlay for ip header used by other protocols (tcp, udp).
>   */
> struct ipovly {
>      caddr_t    ih_next;
>      caddr_t ih_prev;        /* for protocol sequence q's */
>      u_char    ih_x1;            /* (unused) */
>      u_char    ih_pr;            /* protocol */
>      u_short    ih_len;            /* protocol length */
>      struct    in_addr ih_src;        /* source internet address */
>      struct    in_addr ih_dst;        /* destination internet address */
> };
>
> The caddr_t is a pointer. This is what I meant with a lot more problems.
>
> In the new stack we have:
>
> /*
>   * Overlay for ip header used by other protocols (tcp, udp).
>   */
> struct ipovly {
>      u_char    ih_x1[9];        /* (unused) */
>      u_char    ih_pr;            /* protocol */
>      u_short    ih_len;            /* protocol length */
>      struct    in_addr ih_src;        /* source internet address */
>      struct    in_addr ih_dst;        /* destination internet address */
> };
>
> I am not sure if the old stack ever worked on a 64-bit target.
>


--
Hesham