Use framework hints to determine dns query type.
Instead of checking for IPv4 or IPv6 connectivity, try using pid-specific
hints the framework has left for us.
bug:5284168
Change-Id: Id64d48db3900865a7d58ada8309870c63d6eab12
diff --git a/libc/netbsd/net/getaddrinfo.c b/libc/netbsd/net/getaddrinfo.c
index cf05036..965965f 100644
--- a/libc/netbsd/net/getaddrinfo.c
+++ b/libc/netbsd/net/getaddrinfo.c
@@ -188,8 +188,8 @@
#endif
static const ns_src default_dns_files[] = {
- { NSSRC_FILES, NS_SUCCESS },
- { NSSRC_DNS, NS_SUCCESS },
+ { NSSRC_FILES, NS_SUCCESS },
+ { NSSRC_DNS, NS_SUCCESS },
{ 0, 0 }
};
@@ -247,61 +247,61 @@
"Success",
"Address family for hostname not supported", /* EAI_ADDRFAMILY */
"Temporary failure in name resolution", /* EAI_AGAIN */
- "Invalid value for ai_flags", /* EAI_BADFLAGS */
- "Non-recoverable failure in name resolution", /* EAI_FAIL */
+ "Invalid value for ai_flags", /* EAI_BADFLAGS */
+ "Non-recoverable failure in name resolution", /* EAI_FAIL */
"ai_family not supported", /* EAI_FAMILY */
- "Memory allocation failure", /* EAI_MEMORY */
- "No address associated with hostname", /* EAI_NODATA */
+ "Memory allocation failure", /* EAI_MEMORY */
+ "No address associated with hostname", /* EAI_NODATA */
"hostname nor servname provided, or not known", /* EAI_NONAME */
"servname not supported for ai_socktype", /* EAI_SERVICE */
- "ai_socktype not supported", /* EAI_SOCKTYPE */
- "System error returned in errno", /* EAI_SYSTEM */
+ "ai_socktype not supported", /* EAI_SOCKTYPE */
+ "System error returned in errno", /* EAI_SYSTEM */
"Invalid value for hints", /* EAI_BADHINTS */
"Resolved protocol is unknown", /* EAI_PROTOCOL */
"Argument buffer overflow", /* EAI_OVERFLOW */
- "Unknown error", /* EAI_MAX */
+ "Unknown error", /* EAI_MAX */
};
/* XXX macros that make external reference is BAD. */
-#define GET_AI(ai, afd, addr) \
-do { \
- /* external reference: pai, error, and label free */ \
- (ai) = get_ai(pai, (afd), (addr)); \
- if ((ai) == NULL) { \
- error = EAI_MEMORY; \
- goto free; \
- } \
+#define GET_AI(ai, afd, addr) \
+do { \
+ /* external reference: pai, error, and label free */ \
+ (ai) = get_ai(pai, (afd), (addr)); \
+ if ((ai) == NULL) { \
+ error = EAI_MEMORY; \
+ goto free; \
+ } \
} while (/*CONSTCOND*/0)
-#define GET_PORT(ai, serv) \
-do { \
- /* external reference: error and label free */ \
- error = get_port((ai), (serv), 0); \
- if (error != 0) \
- goto free; \
+#define GET_PORT(ai, serv) \
+do { \
+ /* external reference: error and label free */ \
+ error = get_port((ai), (serv), 0); \
+ if (error != 0) \
+ goto free; \
} while (/*CONSTCOND*/0)
-#define GET_CANONNAME(ai, str) \
-do { \
- /* external reference: pai, error and label free */ \
- error = get_canonname(pai, (ai), (str)); \
- if (error != 0) \
- goto free; \
+#define GET_CANONNAME(ai, str) \
+do { \
+ /* external reference: pai, error and label free */ \
+ error = get_canonname(pai, (ai), (str)); \
+ if (error != 0) \
+ goto free; \
} while (/*CONSTCOND*/0)
-#define ERR(err) \
-do { \
- /* external reference: error, and label bad */ \
- error = (err); \
- goto bad; \
- /*NOTREACHED*/ \
+#define ERR(err) \
+do { \
+ /* external reference: error, and label bad */ \
+ error = (err); \
+ goto bad; \
+ /*NOTREACHED*/ \
} while (/*CONSTCOND*/0)
-#define MATCH_FAMILY(x, y, w) \
- ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || \
+#define MATCH_FAMILY(x, y, w) \
+ ((x) == (y) || (/*CONSTCOND*/(w) && ((x) == PF_UNSPEC || \
(y) == PF_UNSPEC)))
-#define MATCH(x, y, w) \
+#define MATCH(x, y, w) \
((x) == (y) || (/*CONSTCOND*/(w) && ((x) == ANY || (y) == ANY)))
const char *
@@ -377,26 +377,42 @@
* available, but whether addresses of the specified family are "configured
* on the local system". However, bionic doesn't currently support getifaddrs,
* so checking for connectivity is the next best thing.
+ *
+ * Note that simply checking connectivity is going to do the wrong thing on
+ * multihomed devices. Now we pass in a hint from the framework about what
+ * to use for this request ("v4", "v4v6", or "v6").
*/
static int
-_have_ipv6() {
- static const struct sockaddr_in6 sin6_test = {
- .sin6_family = AF_INET6,
- .sin6_addr.s6_addr = { // 2000::
- 0x20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
- };
- sockaddr_union addr = { .in6 = sin6_test };
- return _test_connect(PF_INET6, &addr.generic, sizeof(addr.in6));
+_have_ipv6(const char *propvalue) {
+ if (*propvalue != 0) {
+ if ((strcmp(propvalue, "v4v6") == 0) || (strcmp(propvalue, "v6") == 0)) {
+ return 1;
+ } else {
+ return 0;
+ }
+ } else {
+ static const struct sockaddr_in6 sin6_test = {
+ .sin6_family = AF_INET6,
+ .sin6_addr.s6_addr = { // 2000::
+ 0x20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}
+ };
+ sockaddr_union addr = { .in6 = sin6_test };
+ return _test_connect(PF_INET6, &addr.generic, sizeof(addr.in6));
+ }
}
static int
-_have_ipv4() {
- static const struct sockaddr_in sin_test = {
- .sin_family = AF_INET,
- .sin_addr.s_addr = __constant_htonl(0x08080808L) // 8.8.8.8
- };
- sockaddr_union addr = { .in = sin_test };
- return _test_connect(PF_INET, &addr.generic, sizeof(addr.in));
+_have_ipv4(const char *propvalue) {
+ if (*propvalue != 0) {
+ return (strncmp(propvalue, "v4", 2) == 0);
+ } else {
+ static const struct sockaddr_in sin_test = {
+ .sin_family = AF_INET,
+ .sin_addr.s_addr = __constant_htonl(0x08080808L) // 8.8.8.8
+ };
+ sockaddr_union addr = { .in = sin_test };
+ return _test_connect(PF_INET, &addr.generic, sizeof(addr.in));
+ }
}
// Returns 0 on success, else returns non-zero on error (in which case
@@ -1375,9 +1391,9 @@
}
cp += n; /* name */
type = _getshort(cp);
- cp += INT16SZ; /* type */
+ cp += INT16SZ; /* type */
class = _getshort(cp);
- cp += INT16SZ + INT32SZ; /* class, TTL */
+ cp += INT16SZ + INT32SZ; /* class, TTL */
n = _getshort(cp);
cp += INT16SZ; /* len */
if (class != C_IN) {
@@ -1616,8 +1632,8 @@
} else if (IN6_IS_ADDR_TEREDO(&addr6->sin6_addr)) {
return 10;
} else if (IN6_IS_ADDR_V4COMPAT(&addr6->sin6_addr) ||
- IN6_IS_ADDR_SITELOCAL(&addr6->sin6_addr) ||
- IN6_IS_ADDR_6BONE(&addr6->sin6_addr)) {
+ IN6_IS_ADDR_SITELOCAL(&addr6->sin6_addr) ||
+ IN6_IS_ADDR_6BONE(&addr6->sin6_addr)) {
return 1;
} else {
return 40;
@@ -1909,8 +1925,16 @@
q.anslen = sizeof(buf->buf);
int query_ipv6 = 1, query_ipv4 = 1;
if (pai->ai_flags & AI_ADDRCONFIG) {
- query_ipv6 = _have_ipv6();
- query_ipv4 = _have_ipv4();
+ /* check if the fwk gave us a hint */
+ char propname[PROP_NAME_MAX];
+ char propvalue[PROP_VALUE_MAX];
+ propvalue[0] = 0;
+ snprintf(propname, sizeof(propname), "net.dnsproto.%d", getpid());
+ if (__system_property_get(propname, propvalue) <= 0) {
+ __system_property_get("net.dnsproto", propvalue);
+ }
+ query_ipv6 = _have_ipv6(propvalue);
+ query_ipv4 = _have_ipv4(propvalue);
}
if (query_ipv6) {
q.qtype = T_AAAA;
@@ -2336,7 +2360,7 @@
* we only wanted one iteration of the loop, so stop.
*/
if (!(res->options & RES_DNSRCH))
- done++;
+ done++;
}
}
