On 03/19/2018 07:28 PM, Jim Fehlig wrote:
When preparing for migration, the libxl driver creates a new TCP listen socket for the incoming migration by calling virNetSocketNewListenTCP, passing the destination host name. virNetSocketNewListenTCP calls virSocketAddrParse to check if the host name is a wildcard address, in which case it avoids adding the AI_ADDRCONFIG flag to the hints passed to getaddrinfo. If the host name is not an IP address, virSocketAddrParse reports an error
error : virSocketAddrParseInternal:121 : Cannot parse socket address 'myhost.example.com': Name or service not known
But virNetSocketNewListenTCP succeeds regardless and the overall migration operation succeeds.
Introduce virSocketAddrParseQuiet and use it when simply testing if a host name/addr is parsable.
Signed-off-by: Jim Fehlig <jfehlig@suse.com> ---
A brute-force hack that also works is to remove AI_NUMERICHOST flag from hints in virSocketAddrParseInternal, but I'm not sure what sort of havoc that would wreak
Perhaps rather than quiet/verbose flag - maybe ParseInternal should add a new parameter "ai_flags"? Then add virSocketAddrParseName which would pass 0 instead of AI_NUMERICHOST and expect to parse the name. FWIW, I have a faint recollection of some issue with getaddrinfo and dns delays on lookups when looking up by name. Been a while since I've had to think about that though, so I could be wrong as the memory fades/ages. You could also search on some other direct callers of getaddrinfo in libvirt sources - there's some interesting uses.. I also note (ironically) that if @addr == NULL, then error is splatted in ParseInternal regardless of @reportError value.
Perhaps I should ask the obvious question first: Is virSocketAddrParse expected to work with a host name? I suspec there are other callers that could pass a name as well as a numeric IP addr, depending on URI provided by user.
Seems to me some comments [1] answer your question. There's a virSocketAddrNumericFamily - maybe that'll help you in deciding how to formulate things... Seems to be used by a few places already to determine whether one has a name or number (including the qemu migration path). FWIW: I also note callers to virSocketAddrNumericFamily don't necessarily handle the possible -1 return possibly... Looks like you're jumping into one of rabbit holes Laine usually falls into ;-)
src/libvirt_private.syms | 1 + src/rpc/virnetsocket.c | 2 +- src/util/virsocketaddr.c | 60 +++++++++++++++++++++++++++++++++++------------- src/util/virsocketaddr.h | 4 ++++ 4 files changed, 50 insertions(+), 17 deletions(-)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms index c3e4fd23d..acacbaeb1 100644 --- a/src/libvirt_private.syms +++ b/src/libvirt_private.syms @@ -2726,6 +2726,7 @@ virSocketAddrNumericFamily; virSocketAddrParse; virSocketAddrParseIPv4; virSocketAddrParseIPv6; +virSocketAddrParseQuiet; virSocketAddrPrefixToNetmask; virSocketAddrPTRDomain; virSocketAddrSetIPv4Addr; diff --git a/src/rpc/virnetsocket.c b/src/rpc/virnetsocket.c index 2d41a716b..07166ecc9 100644 --- a/src/rpc/virnetsocket.c +++ b/src/rpc/virnetsocket.c @@ -333,7 +333,7 @@ int virNetSocketNewListenTCP(const char *nodename, * startup in most cases. */ if (nodename && - !(virSocketAddrParse(&tmp_addr, nodename, AF_UNSPEC) > 0 && + !(virSocketAddrParseQuiet(&tmp_addr, nodename, AF_UNSPEC) > 0 && virSocketAddrIsWildcard(&tmp_addr))) hints.ai_flags |= AI_ADDRCONFIG;
diff --git a/src/util/virsocketaddr.c b/src/util/virsocketaddr.c index 95b527436..711c634e8 100644 --- a/src/util/virsocketaddr.c +++ b/src/util/virsocketaddr.c @@ -126,29 +126,24 @@ virSocketAddrParseInternal(struct addrinfo **res, return 0; }
-/** - * virSocketAddrParse: - * @val: a numeric network address IPv4 or IPv6 - * @addr: where to store the return value, optional. - * @family: address family to pass down to getaddrinfo - * - * Mostly a wrapper for getaddrinfo() extracting the address storage - * from the numeric string like 1.2.3.4 or 2001:db8:85a3:0:0:8a2e:370:7334 - *
[1]
- * Returns the length of the network address or -1 in case of error. - */ -int virSocketAddrParse(virSocketAddrPtr addr, const char *val, int family) +static int +virSockAddrParseVerbose(virSocketAddrPtr addr, + const char *val, + int family, + bool verbose)
Could have gone with reportError like ParseInternal. John
{ int len; struct addrinfo *res;
- if (virSocketAddrParseInternal(&res, val, family, true) < 0) + if (virSocketAddrParseInternal(&res, val, family, verbose) < 0) return -1;
if (res == NULL) { - virReportError(VIR_ERR_SYSTEM_ERROR, - _("No socket addresses found for '%s'"), - val); + if (verbose) { + virReportError(VIR_ERR_SYSTEM_ERROR, + _("No socket addresses found for '%s'"), + val); + } return -1; }
@@ -162,6 +157,39 @@ int virSocketAddrParse(virSocketAddrPtr addr, const char *val, int family) return len; }
+ +/** + * virSocketAddrParse: + * @val: a numeric network address IPv4 or IPv6 + * @addr: where to store the return value, optional. + * @family: address family to pass down to getaddrinfo + * + * Mostly a wrapper for getaddrinfo() extracting the address storage + * from the numeric string like 1.2.3.4 or 2001:db8:85a3:0:0:8a2e:370:7334 + * + * Returns the length of the network address or -1 in case of error. + */ +int virSocketAddrParse(virSocketAddrPtr addr, const char *val, int family) +{ + return virSockAddrParseVerbose(addr, val, family, true); +} + +/** + * virSocketAddrParseQuiet: + * @val: a numeric network address IPv4 or IPv6 + * @addr: where to store the return value, optional. + * @family: address family to pass down to getaddrinfo + * + * A quiet version of virSocketAddrParse. No errors are reported in + * error paths. + * + * Returns the length of the network address or -1 in case of error. + */ +int virSocketAddrParseQuiet(virSocketAddrPtr addr, const char *val, int family) +{ + return virSockAddrParseVerbose(addr, val, family, false); +} + /* * virSocketAddrParseIPv4: * @val: an IPv4 numeric address diff --git a/src/util/virsocketaddr.h b/src/util/virsocketaddr.h index 80e792618..99bb7a949 100644 --- a/src/util/virsocketaddr.h +++ b/src/util/virsocketaddr.h @@ -92,6 +92,10 @@ int virSocketAddrParse(virSocketAddrPtr addr, const char *val, int family);
+int virSocketAddrParseQuiet(virSocketAddrPtr addr, + const char *val, + int family); + int virSocketAddrParseIPv4(virSocketAddrPtr addr, const char *val);