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path: root/resolv/nss_dns/dns-host.c
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Diffstat (limited to 'resolv/nss_dns/dns-host.c')
-rw-r--r--resolv/nss_dns/dns-host.c70
1 files changed, 54 insertions, 16 deletions
diff --git a/resolv/nss_dns/dns-host.c b/resolv/nss_dns/dns-host.c
index c7bfc13aab..39eccabbdf 100644
--- a/resolv/nss_dns/dns-host.c
+++ b/resolv/nss_dns/dns-host.c
@@ -132,12 +132,13 @@ _nss_dns_gethostbyname2_r (const char *name, int af, struct hostent *result,
char *buffer, size_t buflen, int *errnop,
int *h_errnop)
{
- querybuf host_buffer;
+ querybuf *host_buffer;
char tmp[NS_MAXDNAME];
int size, type, n;
const char *cp;
- int map = 0;
+ int map = 0, use_malloc = 0;
int olderr = errno;
+ enum nss_status status;
if ((_res.options & RES_INIT) == 0 && __res_ninit (&_res) == -1)
return NSS_STATUS_UNAVAIL;
@@ -169,8 +170,21 @@ _nss_dns_gethostbyname2_r (const char *name, int af, struct hostent *result,
&& (cp = res_hostalias (&_res, name, tmp, sizeof (tmp))) != NULL)
name = cp;
- n = res_nsearch (&_res, name, C_IN, type, host_buffer.buf,
- sizeof (host_buffer.buf));
+ if (!__libc_use_alloca (MAXPACKET))
+ {
+ host_buffer = (querybuf *) malloc (sizeof (querybuf));
+ if (host_buffer == NULL)
+ {
+ *errnop = ENOMEM;
+ return NSS_STATUS_UNAVAIL;
+ }
+ use_malloc = 1;
+ }
+ else
+ host_buffer = (querybuf *) alloca (sizeof (querybuf));
+
+ n = res_nsearch (&_res, name, C_IN, type, host_buffer->buf,
+ sizeof (host_buffer->buf));
if (n < 0)
{
enum nss_status status = (errno == ECONNREFUSED
@@ -185,11 +199,15 @@ _nss_dns_gethostbyname2_r (const char *name, int af, struct hostent *result,
by having the RES_USE_INET6 bit in _res.options set, we try
another lookup. */
if (af == AF_INET6 && (_res.options & RES_USE_INET6))
- n = res_nsearch (&_res, name, C_IN, T_A, host_buffer.buf,
- sizeof (host_buffer.buf));
+ n = res_nsearch (&_res, name, C_IN, T_A, host_buffer->buf,
+ sizeof (host_buffer->buf));
if (n < 0)
- return status;
+ {
+ if (use_malloc)
+ free (host_buffer);
+ return status;
+ }
map = 1;
@@ -197,8 +215,11 @@ _nss_dns_gethostbyname2_r (const char *name, int af, struct hostent *result,
result->h_length = INADDRSZ;;
}
- return getanswer_r (&host_buffer, n, name, type, result, buffer, buflen,
- errnop, h_errnop, map);
+ status = getanswer_r (host_buffer, n, name, type, result, buffer, buflen,
+ errnop, h_errnop, map);
+ if (use_malloc)
+ free (host_buffer);
+ return status;
}
@@ -236,10 +257,10 @@ _nss_dns_gethostbyaddr_r (const void *addr, socklen_t len, int af,
char *h_addr_ptrs[MAX_NR_ADDRS + 1];
char linebuffer[0];
} *host_data = (struct host_data *) buffer;
- querybuf host_buffer;
+ querybuf *host_buffer;
char qbuf[MAXDNAME+1], *qp = NULL;
size_t size;
- int n, status;
+ int n, status, use_malloc = 0;
int olderr = errno;
if ((_res.options & RES_INIT) == 0 && __res_ninit (&_res) == -1)
@@ -294,23 +315,40 @@ _nss_dns_gethostbyaddr_r (const void *addr, socklen_t len, int af,
break;
}
- n = res_nquery (&_res, qbuf, C_IN, T_PTR, (u_char *)host_buffer.buf,
- sizeof host_buffer);
+ if (!__libc_use_alloca (MAXPACKET))
+ {
+ host_buffer = (querybuf *) malloc (sizeof (querybuf));
+ if (host_buffer == NULL)
+ {
+ *errnop = ENOMEM;
+ return NSS_STATUS_UNAVAIL;
+ }
+ use_malloc = 1;
+ }
+ else
+ host_buffer = (querybuf *) alloca (sizeof (querybuf));
+
+ n = res_nquery (&_res, qbuf, C_IN, T_PTR, host_buffer->buf,
+ sizeof (host_buffer->buf));
if (n < 0 && af == AF_INET6)
{
strcpy (qp, "ip6.int");
- n = res_nquery (&_res, qbuf, C_IN, T_PTR, (u_char *)host_buffer.buf,
- sizeof host_buffer);
+ n = res_nquery (&_res, qbuf, C_IN, T_PTR, host_buffer->buf,
+ sizeof (host_buffer->buf));
}
if (n < 0)
{
*h_errnop = h_errno;
__set_errno (olderr);
+ if (use_malloc)
+ free (host_buffer);
return errno == ECONNREFUSED ? NSS_STATUS_UNAVAIL : NSS_STATUS_NOTFOUND;
}
- status = getanswer_r (&host_buffer, n, qbuf, T_PTR, result, buffer, buflen,
+ status = getanswer_r (host_buffer, n, qbuf, T_PTR, result, buffer, buflen,
errnop, h_errnop, 0 /* XXX */);
+ if (use_malloc)
+ free (host_buffer);
if (status != NSS_STATUS_SUCCESS)
{
*h_errnop = h_errno;