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-rw-r--r--libc/inet/resolv.c78
1 files changed, 45 insertions, 33 deletions
diff --git a/libc/inet/resolv.c b/libc/inet/resolv.c
index 828ca1359..f73329a92 100644
--- a/libc/inet/resolv.c
+++ b/libc/inet/resolv.c
@@ -742,8 +742,25 @@ static int static_ns = 0;
* rw data costs more. */
static uint16_t static_id = 1;
-int attribute_hidden __dns_lookup(const char *name, int type, int nscount, char **nsip,
- unsigned char **outpacket, struct resolv_answer *a)
+/* On entry:
+ * a.buf(len) = auxiliary buffer for IP addresses after first one
+ * a.add_count = how many additional addresses are there already
+ * outpacket = where to save ptr to raw packet? can be NULL
+ * On exit:
+ * ret < 0: error, all other data is not valid
+ * a.add_count & a.buf: updated
+ * a.rdlength: length of addresses (4 bytes for IPv4)
+ * *outpacket: updated (packet is malloced, you need to free it)
+ * a.rdata: points into *outpacket to 1st IP addr
+ * NB: don't pass outpacket == NULL if you need to use a.rdata!
+ * a.atype: type of query?
+ * a.dotted: numeric IP as a string (malloced, may be NULL if strdup failed)
+ * (which one of potentially many??)
+ */
+int attribute_hidden __dns_lookup(const char *name, int type,
+ int nscount, char **nsip,
+ unsigned char **outpacket,
+ struct resolv_answer *a)
{
int i, j, len, fd, pos, rc;
#ifdef USE_SELECT
@@ -762,13 +779,15 @@ int attribute_hidden __dns_lookup(const char *name, int type, int nscount, char
int variant = -1; /* search domain to append, -1 - none */
int local_ns = -1, local_id = -1;
bool ends_with_dot;
-#ifdef __UCLIBC_HAS_IPV6__
- bool v6;
- struct sockaddr_in6 sa6;
-#endif
+ union {
+ struct sockaddr sa;
#ifdef __UCLIBC_HAS_IPV4__
- struct sockaddr_in sa;
+ struct sockaddr_in sa4;
#endif
+#ifdef __UCLIBC_HAS_IPV6__
+ struct sockaddr_in6 sa6;
+#endif
+ } sa;
fd = -1;
@@ -841,43 +860,38 @@ int attribute_hidden __dns_lookup(const char *name, int type, int nscount, char
DPRINTF("On try %d, sending query to port %d of machine %s\n",
retries+1, NAMESERVER_PORT, dns);
+ sa.sa.sa_family = AF_INET;
#ifdef __UCLIBC_HAS_IPV6__
//__UCLIBC_MUTEX_LOCK(__resolv_lock);
///* 'dns' is really __nameserver[] which is a global that
// needs to hold __resolv_lock before access!! */
- v6 = inet_pton(AF_INET6, dns, &sa6.sin6_addr) > 0;
+ if (inet_pton(AF_INET6, dns, &sa.sa6.sin6_addr) > 0)
+ sa.sa.sa_family = AF_INET6;
//__UCLIBC_MUTEX_UNLOCK(__resolv_lock);
- fd = socket(v6 ? AF_INET6 : AF_INET, SOCK_DGRAM, IPPROTO_UDP);
-#else
- fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
#endif
- if (fd < 0) {
- retries++;
- continue;
- }
-
/* Connect to the UDP socket so that asyncronous errors are returned */
#ifdef __UCLIBC_HAS_IPV6__
- if (v6) {
- sa6.sin6_family = AF_INET6;
- sa6.sin6_port = htons(NAMESERVER_PORT);
+ if (sa.sa.sa_family == AF_INET6) {
+ sa.sa6.sin6_port = htons(NAMESERVER_PORT);
/* sa6.sin6_addr is already here */
- rc = connect(fd, (struct sockaddr *) &sa6, sizeof(sa6));
- } else {
+ } else
#endif
#ifdef __UCLIBC_HAS_IPV4__
- sa.sin_family = AF_INET;
- sa.sin_port = htons(NAMESERVER_PORT);
+ {
+ sa.sa4.sin_port = htons(NAMESERVER_PORT);
//__UCLIBC_MUTEX_LOCK(__resolv_lock);
///* 'dns' is really __nameserver[] which is a global that
// needs to hold __resolv_lock before access!! */
- sa.sin_addr.s_addr = inet_addr(dns);
+ sa.sa4.sin_addr.s_addr = inet_addr(dns);
//__UCLIBC_MUTEX_UNLOCK(__resolv_lock);
- rc = connect(fd, (struct sockaddr *) &sa, sizeof(sa));
-#endif
-#ifdef __UCLIBC_HAS_IPV6__
}
#endif
+ fd = socket(sa.sa.sa_family, SOCK_DGRAM, IPPROTO_UDP);
+ if (fd < 0) {
+ retries++;
+ continue;
+ }
+ rc = connect(fd, &sa.sa, sizeof(sa));
if (rc < 0) {
if (errno == ENETUNREACH) {
/* routing error, presume not transient */
@@ -900,7 +914,6 @@ int attribute_hidden __dns_lookup(const char *name, int type, int nscount, char
tv.tv_usec = 0;
if (select(fd + 1, &fds, NULL, NULL, &tv) <= 0) {
DPRINTF("Timeout\n");
-
/* timed out, so retry send and receive,
* to next nameserver on queue */
goto tryall;
@@ -910,7 +923,6 @@ int attribute_hidden __dns_lookup(const char *name, int type, int nscount, char
fds.events = POLLIN;
if (poll(&fds, 1, REPLY_TIMEOUT * 1000) <= 0) {
DPRINTF("Timeout\n");
-
/* timed out, so retry send and receive,
* to next nameserver on queue */
goto tryall;
@@ -967,9 +979,8 @@ int attribute_hidden __dns_lookup(const char *name, int type, int nscount, char
DPRINTF("Decoding answer at pos %d\n", pos);
first_answer = 1;
- for (j = 0; j < h.ancount && pos < len; j++, pos += i) {
+ for (j = 0; j < h.ancount && pos < len; j++) {
i = __decode_answer(packet, pos, len, &ma);
-
if (i < 0) {
DPRINTF("failed decode %d\n", i);
/* if the message was truncated and we have
@@ -978,13 +989,14 @@ int attribute_hidden __dns_lookup(const char *name, int type, int nscount, char
break;
goto again;
}
+ pos += i;
if (first_answer) {
ma.buf = a->buf;
ma.buflen = a->buflen;
ma.add_count = a->add_count;
memcpy(a, &ma, sizeof(ma));
- if (a->atype != T_SIG && (0 == a->buf || (type != T_A && type != T_AAAA)))
+ if (a->atype != T_SIG && (NULL == a->buf || (type != T_A && type != T_AAAA)))
break;
if (a->atype != type) {
free(a->dotted);
@@ -1288,7 +1300,7 @@ int res_query(const char *dname, int class, int type,
unsigned char *answer, int anslen)
{
int i;
- unsigned char * packet = 0;
+ unsigned char * packet = NULL;
struct resolv_answer a;
int __nameserversXX;
char ** __nameserverXX;
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-01 20:25:37 +0000