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, 0 deletions

diff --git a/src/network/getaddrinfo.c b/src/network/getaddrinfo.c
index 70b6cfda..d9913445 100644
--- a/src/network/getaddrinfo.c
+++ b/src/network/getaddrinfo.c
@@ -105,6 +105,7 @@ int getaddrinfo(const char *restrict host, const char *restrict serv, const stru
 		case AF_INET6:
 			out[k].sa.sin6.sin6_family = AF_INET6;
 			out[k].sa.sin6.sin6_port = htons(ports[j].port);
+			out[k].sa.sin6.sin6_scope_id = addrs[i].scopeid;
 			memcpy(&out[k].sa.sin6.sin6_addr, &addrs[i].addr, 16);
 			break;			
 		}