[PATCH] rpc: 'getaddrinfo' function support both IPv4 and IPv6
If only IPv6 is configured and nscd is started, getaddrinfo function reture value is -9. So hints.ai_flags should include the AI_V4MAPPED flag. The following is the partial implementation of getaddrinfo(glibc): if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET) at->family = AF_INET; else if (req->ai_family == AF_INET6 && (req->ai_flags & AI_V4MAPPED)) { at->addr[3] = at->addr[0]; at->addr[2] = htonl (0xffff); at->addr[1] = 0; at->addr[0] = 0; at->family = AF_INET6; } else { result = -EAI_ADDRFAMILY; goto free_and_return; } Signed-off-by: Zhimin Feng <fengzhimin1@huawei.com> --- src/rpc/virnetsocket.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/src/rpc/virnetsocket.c b/src/rpc/virnetsocket.c index a217404fa6..c547acefc0 100644 --- a/src/rpc/virnetsocket.c +++ b/src/rpc/virnetsocket.c @@ -575,7 +575,7 @@ int virNetSocketNewConnectTCP(const char *nodename, memset(&hints, 0, sizeof(hints)); hints.ai_family = family; - hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG; + hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG | AI_V4MAPPED; hints.ai_socktype = SOCK_STREAM; int e = getaddrinfo(nodename, service, &hints, &ai); -- 2.19.1
The commit summary is too generic. How about: rpc: getaddrinfo: also accept IPv4-mapped IPv6 addresses On a Monday in 2020, Zhimin Feng wrote:
If only IPv6 is configured and nscd is started, getaddrinfo
Is ncsd required to reproduce this? Looking at glibc source: libvirt passes AI_ADDRCONFIG and if getifaddrs returs only one family, it is placed into req->ai_family and the code below is hit.
function reture value is -9. So hints.ai_flags should include the AI_V4MAPPED flag.
The following is the partial implementation of getaddrinfo(glibc):
if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET) at->family = AF_INET; else if (req->ai_family == AF_INET6 && (req->ai_flags & AI_V4MAPPED)) { at->addr[3] = at->addr[0]; at->addr[2] = htonl (0xffff); at->addr[1] = 0; at->addr[0] = 0; at->family = AF_INET6; } else { result = -EAI_ADDRFAMILY; goto free_and_return; }
However small, I'd rather not include GPL code in our commit messages. Proposed commit message: If only IPv6 is configured on the host, getaddrinfo with AI_ADDRCONFIG in hints would return EAI_ADDRFAMILY for nodenames that resolve to IPv4. Also pass AI_V4MAPPED to accept IPv4-mapped addresses on IPv6-only systems.
Signed-off-by: Zhimin Feng <fengzhimin1@huawei.com> --- src/rpc/virnetsocket.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/rpc/virnetsocket.c b/src/rpc/virnetsocket.c index a217404fa6..c547acefc0 100644 --- a/src/rpc/virnetsocket.c +++ b/src/rpc/virnetsocket.c @@ -575,7 +575,7 @@ int virNetSocketNewConnectTCP(const char *nodename,
memset(&hints, 0, sizeof(hints)); hints.ai_family = family; - hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG; + hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG | AI_V4MAPPED; hints.ai_socktype = SOCK_STREAM;
int e = getaddrinfo(nodename, service, &hints, &ai);
Reviewed-by: Ján Tomko <jtomko@redhat.com> Jano
On Mon, Mar 02, 2020 at 05:54:42PM +0100, Ján Tomko wrote:
The commit summary is too generic. How about: rpc: getaddrinfo: also accept IPv4-mapped IPv6 addresses
On a Monday in 2020, Zhimin Feng wrote:
If only IPv6 is configured and nscd is started, getaddrinfo
Is ncsd required to reproduce this?
Looking at glibc source: libvirt passes AI_ADDRCONFIG and if getifaddrs returs only one family, it is placed into req->ai_family and the code below is hit.
function reture value is -9. So hints.ai_flags should include the AI_V4MAPPED flag.
The following is the partial implementation of getaddrinfo(glibc):
if (req->ai_family == AF_UNSPEC || req->ai_family == AF_INET) at->family = AF_INET; else if (req->ai_family == AF_INET6 && (req->ai_flags & AI_V4MAPPED)) { at->addr[3] = at->addr[0]; at->addr[2] = htonl (0xffff); at->addr[1] = 0; at->addr[0] = 0; at->family = AF_INET6; } else { result = -EAI_ADDRFAMILY; goto free_and_return; }
However small, I'd rather not include GPL code in our commit messages. Proposed commit message:
If only IPv6 is configured on the host, getaddrinfo with AI_ADDRCONFIG in hints would return EAI_ADDRFAMILY for nodenames that resolve to IPv4.
Also pass AI_V4MAPPED to accept IPv4-mapped addresses on IPv6-only systems.
Signed-off-by: Zhimin Feng <fengzhimin1@huawei.com> --- src/rpc/virnetsocket.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/src/rpc/virnetsocket.c b/src/rpc/virnetsocket.c index a217404fa6..c547acefc0 100644 --- a/src/rpc/virnetsocket.c +++ b/src/rpc/virnetsocket.c @@ -575,7 +575,7 @@ int virNetSocketNewConnectTCP(const char *nodename,
memset(&hints, 0, sizeof(hints)); hints.ai_family = family; - hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG; + hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG | AI_V4MAPPED; hints.ai_socktype = SOCK_STREAM;
int e = getaddrinfo(nodename, service, &hints, &ai);
Reviewed-by: Ján Tomko <jtomko@redhat.com>
I noticed that glibc man pages say if ai_flags is 0, then it defaults to AI_ADDRCONFIG | AI_V4MAPPED. Libvirt had to set ai_flags to get the AI_PASSIVE flag, and so given that adding AI_V4MAPPED makes sense to regain the default behaviour we're loosing. Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
participants (3)
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Daniel P. Berrangé -
Ján Tomko -
Zhimin Feng