Le lundi 31 décembre 2012 à 21:32 +0000, Peter Maydell a écrit :
> On 31 December 2012 19:38, Laurent Vivier <laur...@vivier.eu> wrote:
> > @@ -1900,6 +1900,12 @@ static abi_long do_socket(int domain, int type, int
> > protocol)
> > #endif
> > if (domain == PF_NETLINK)
> > return -EAFNOSUPPORT; /* do not NETLINK socket connections
> > possible */
> > + if (type == SOCK_PACKET) {
> > + /* in this case, socket() needs a network endian short */
> > + protocol = tswapal(protocol); /* restore network endian long */
> > + protocol = abi_ntohl(protocol); /* a host endian long */
> > + protocol = htons(protocol); /* network endian short */
> > + }
>
> Are you sure this is correct for little endian guests? I've only
> desk-checked it rather than running a test program, but it looks
> to me like you end up passing the wrong value to socket().
I tried to find a solution working in every case.
> Also it seems rather involved since we swap things three times and
> have an entirely new abi_* function. Either I'm completely confused
> or it should be enough to just have
>
> if (type == SOCK_PACKET) {
> protocol = tswap16(protocol);
> }
works... sometime. In fact, work if target endianess is network endianess.
Correct me if I'm wrong.
target host
little endian / big endian
memory 00 00 00 03
protocol 03000000
tswap16 00000000 -> don't work
tswapal() 00000003
abi_ntohl() 00000003
htons() 00000003 -> work
big endian / little endian:
memory 00 00 00 03
protocol 00000003
tswap16() 00000300 -> work
tswapal() 03000000
abi_ntohl() 00000003
htons() 00000300 -> work
little endian/little endian:
memory: 00 00 00 03 (network endian)
protocol : 03000000
tswap16() : 00000000 -> don't work
tswapal() 03000000
abi_ntohl() 00000003
htons() 00000300 -> work
big endian / big endian
memory 00 00 00 03
protocol 00000003
tswap16() 00000003 -> work
tswapal() 00000003
abi_ntohl() 00000003
htons() 00000003 -> work
Laurent
--
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