File glibc-bindresvport-blacklist.diff of Package glibc
Index: glibc-2.17.90/sunrpc/bindrsvprt.c
===================================================================
--- glibc-2.17.90.orig/sunrpc/bindrsvprt.c
+++ glibc-2.17.90/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>
@@ -42,6 +45,93 @@
*/
__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 these
+ 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);
+ if (blacklist_read)
+ goto unlock;
+ blacklist_read = 1;
+
+ fp = fopen ("/etc/bindresvport.blacklist", "r");
+ if (fp == NULL)
+ goto unlock;
+
+ while (!feof_unlocked (fp))
+ {
+ unsigned long port;
+ char *tmp, *cp;
+ ssize_t n = __getline (&buf, &buflen, fp);
+ if (n < 1)
+ break;
+
+ cp = buf;
+ /* Remove comments. */
+ tmp = strchr (cp, '#');
+ if (tmp)
+ *tmp = '\0';
+ /* Remove spaces and tabs. */
+ while (isspace ((unsigned char) *cp))
+ ++cp;
+ /* Ignore empty lines. */
+ if (*cp == '\0')
+ continue;
+ if (cp[strlen (cp) - 1] == '\n')
+ cp[strlen (cp) - 1] = '\0';
+
+ port = strtoul (cp, &tmp, 0);
+ while (isspace ((unsigned char) *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;
+ int *new_list = realloc (list, size * sizeof (int));
+ if (new_list == NULL)
+ {
+ free (list);
+ list = NULL;
+ free (buf);
+ goto unlock;
+ }
+ list = new_list;
+ }
+
+ list[ptr++] = port;
+ }
+
+ fclose (fp);
+ free (buf);
+ list_size = ptr;
+
+ unlock:
+ __libc_lock_unlock (lock);
+}
+
+
/*
* Bind a socket to a privileged IP port
*/
@@ -52,12 +142,11 @@ bindresvport (int sd, struct sockaddr_in
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)
{
sin = &myaddr;
@@ -75,6 +164,7 @@ bindresvport (int sd, struct sockaddr_in
port = (__getpid () % NPORTS) + STARTPORT;
}
+ __set_errno (EADDRINUSE);
/* Initialize to make gcc happy. */
int res = -1;
@@ -86,12 +176,22 @@ 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 that 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)