add support for ipv6 scope_id to getaddrinfo and getnameinfo

for all address types, a scope_id specified as a decimal value is
accepted. for addresses with link-local scope, a string containing the
interface name is also accepted.

some changes are made to error handling to avoid unwanted fallbacks in
the case where the scope_id is invalid: if an earlier name lookup
backend fails with an error rather than simply "0 results", this
failure now suppresses any later attempts with other backends.

in getnameinfo, a light "itoa" type function is added for generating
decimal scope_id results, and decimal port strings for services are
also generated using this function now so as not to pull in the
dependency on snprintf.

in netdb.h, a definition for the NI_NUMERICSCOPE flag is added. this
is required by POSIX (it was previously missing) and needed to allow
callers to suppress interface-name lookups.

1 files changed, 1 insertions, 1 deletions

diff --git a/include/netdb.h b/include/netdb.h
index dfc70e2b..703a4b26 100644
--- a/include/netdb.h
+++ b/include/netdb.h
@@ -41,7 +41,7 @@ struct addrinfo
 #define NI_NOFQDN       0x04
 #define NI_NAMEREQD     0x08
 #define NI_DGRAM        0x10
-/*#define NI_NUMERICSCOPE */
+#define NI_NUMERICSCOPE 0x100
 
 #define EAI_BADFLAGS   -1
 #define EAI_NONAME     -2