glibc/glibc-2.3.90-bindresvport.blacklist.diff

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Index: glibc-2.16.90/sunrpc/bindrsvprt.c
===================================================================
--- glibc-2.16.90.orig/sunrpc/bindrsvprt.c
+++ glibc-2.16.90/sunrpc/bindrsvprt.c
@@ -29,6 +29,9 @@
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
+#include <stdio.h>
+#include <ctype.h>
+#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <string.h>
@@ -42,21 +45,102 @@
*/
__libc_lock_define_initialized (static, lock);
+#define STARTPORT 600
+#define LOWPORT 512
+#define ENDPORT (IPPORT_RESERVED - 1)
+#define NPORTS (ENDPORT - STARTPORT + 1)
+
+/*
+ * Read the file /etc/rpc.blacklisted, so that we don't bind
+ * to this ports.
+ */
+
+static int blacklist_read;
+static int *list;
+static int list_size = 0;
+
+static void
+load_blacklist (void)
+{
+ FILE *fp;
+ char *buf = NULL;
+ size_t buflen = 0;
+ int size = 0, ptr = 0;
+
+ __libc_lock_lock (lock);
+ blacklist_read = 1;
+
+ fp = fopen ("/etc/bindresvport.blacklist", "r");
+ if (NULL == fp)
+ return;
+
+ while (!feof_unlocked (fp))
+ {
+ unsigned long port;
+ char *tmp, *cp;
+ ssize_t n = __getline (&buf, &buflen, fp);
+ if (n < 1)
+ break;
+
+ cp = buf;
+ tmp = strchr (cp, '#'); /* remove comments */
+ if (tmp)
+ *tmp = '\0';
+ while (isspace ((int)*cp)) /* remove spaces and tabs */
+ ++cp;
+ if (*cp == '\0') /* ignore empty lines */
+ continue;
+ if (cp[strlen (cp) - 1] == '\n')
+ cp[strlen (cp) - 1] = '\0';
+
+ port = strtoul (cp, &tmp, 0);
+ while (isspace(*tmp))
+ ++tmp;
+ if (*tmp != '\0' || (port == ULONG_MAX && errno == ERANGE))
+ continue;
+
+ /* Don't bother with out-of-range ports */
+ if (port < LOWPORT || port > ENDPORT)
+ continue;
+
+ if (ptr >= size)
+ {
+ size += 10;
+ list = realloc (list, size * sizeof (int));
+ if (list == NULL)
+ {
+ free (buf);
+ return;
+ }
+ }
+
+ list[ptr++] = port;
+ }
+
+ fclose (fp);
+
+ if (buf)
+ free (buf);
+
+ list_size = ptr;
+
+ __libc_lock_unlock (lock);
+}
+
+
/*
* Bind a socket to a privileged IP port
*/
int
bindresvport (int sd, struct sockaddr_in *sin)
{
+ static short startport = STARTPORT;
static short port;
struct sockaddr_in myaddr;
int i;
-#define STARTPORT 600
-#define LOWPORT 512
-#define ENDPORT (IPPORT_RESERVED - 1)
-#define NPORTS (ENDPORT - STARTPORT + 1)
- static short startport = STARTPORT;
+ if (!blacklist_read)
+ load_blacklist ();
if (sin == (struct sockaddr_in *) 0)
{
@@ -75,6 +159,7 @@ bindresvport (int sd, struct sockaddr_in
port = (__getpid () % NPORTS) + STARTPORT;
}
+ __set_errno (EADDRINUSE);
/* Initialize to make gcc happy. */
int res = -1;
@@ -86,12 +171,22 @@ bindresvport (int sd, struct sockaddr_in
again:
for (i = 0; i < nports; ++i)
{
- sin->sin_port = htons (port++);
- if (port > endport)
- port = startport;
+ int j;
+
+ sin->sin_port = htons (port);
+
+ /* Check, if this port is not blacklisted. */
+ for (j = 0; j < list_size; j++)
+ if (port == list[j])
+ goto try_next_port;
+
res = __bind (sd, sin, sizeof (struct sockaddr_in));
if (res >= 0 || errno != EADDRINUSE)
break;
+
+try_next_port:
+ if (++port > endport)
+ port = startport;
}
if (i == nports && startport != LOWPORT)