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Use framework hints to determine dns query type.

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Instead of checking for IPv4 or IPv6 connectivity, try using pid-specific
hints the framework has left for us.

bug:5284168
Change-Id: Id64d48db3900865a7d58ada8309870c63d6eab12
This commit is contained in:
Robert Greenwalt 2011-09-13 17:33:52 -07:00
parent 3884bfe966
commit 8af58f0fd4
1 changed files with 84 additions and 60 deletions
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144
libc/netbsd/net/getaddrinfo.c
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@ -188,8 +188,8 @@ static const struct explore explore[] = {
#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 @@ static const char * const ai_errlist[] = {
"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 @@ _test_connect(int pf, struct sockaddr *addr, size_t addrlen) {
* 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 @@ getanswer(const querybuf *answer, int anslen, const char *qname, int qtype,
}
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 @@ _get_precedence(const struct sockaddr *addr)
} 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 @@ _dns_getaddrinfo(void *rv, void *cb_data, va_list ap)
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 @@ res_searchN(const char *name, struct res_target *target, res_state res)
* we only wanted one iteration of the loop, so stop.
*/
if (!(res->options & RES_DNSRCH))
done++;
done++;
}
}