Hi, Daniel
On 06/28/2017 09:23 PM, Daniel P. Berrange wrote:
On Wed, Jun 28, 2017 at 09:08:49PM +0800, Mao Zhongyi wrote:
diff --git a/include/qemu/sockets.h b/include/qemu/sockets.h
index 5c326db..78e2b30 100644
--- a/include/qemu/sockets.h
+++ b/include/qemu/sockets.h
if (qemu_isdigit(buf[0])) {
- if (!inet_aton(buf, &saddr->sin_addr))
+ if (!inet_aton(buf, &saddr->sin_addr)) {
+ error_setg(errp, "host address '%s' is not a valid "
+ "IPv4 address", buf);
return -1;
+ }
} else {
- if ((he = gethostbyname(buf)) == NULL)
+ he = gethostbyname(buf);
+ if (he == NULL) {
+ error_setg(errp, "can't resolve host address '%s': "
+ "unknown host", buf);
return - 1;
+ }
gethostbyname sets 'h_errno' on failure, so you should pass that
into error_setg_errno, instead of hardcoding 'unknown host' as a
message
Yes, 'h_errno' will be seted detailed error message when gethostbyname() failed,
but the value of 'h_errno', as far as I know, can be print by hstrerror(),
herror() and gai_strerror(). I'm not sure 'h_errno' can be parsed correctly
by error_setg_errno(), so I test it like this:
herror("----herror----");
error_report("----hstrerror----%s", hstrerror(h_errno));
error_report("----gai_strerror----%s", gai_strerror(h_errno));
error_setg_errno(errp, h_errno, "can't resolve host address '%s'" ,buf);
result:
----herror----: Unknown host
qemu-system-x86_64: -net socket,listen=hostname:: ----hstrerror----Unknown host
qemu-system-x86_64: -net socket,listen=hostname:: ----gai_strerror----Unknown
error
qemu-system-x86_64: -net socket,listen=hostname:: can't resolve host address
'hostname': Operation not permitted
From the results, obviously the error message is different.
error_setg_errno() prints a uncertain message like "Operation not
permitted", I think that the value of 'h_errno' is treated as a
standard error code for errno. Although they have the same value,
the information contained may not be same.
so is it really appropriate to pass 'h_errno' to error_setg_errno()?
Thanks,
Mao
Regards,
Daniel
