Adding upstream version 2.4.59.upstream/2.4.59upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 37 insertions, 17 deletions

diff --git a/modules/metadata/mod_unique_id.c b/modules/metadata/mod_unique_id.c
index 0b05fbf..2555749 100644
--- a/modules/metadata/mod_unique_id.c
+++ b/modules/metadata/mod_unique_id.c
@@ -26,6 +26,11 @@
 #include "apr_general.h"    /* for APR_OFFSETOF                */
 #include "apr_network_io.h"
 
+#ifdef APR_HAS_THREADS
+#include "apr_atomic.h"     /* for apr_atomic_inc32 */
+#include "mpm_common.h"     /* for ap_mpm_query */
+#endif
+
 #include "httpd.h"
 #include "http_config.h"
 #include "http_log.h"
@@ -104,7 +109,7 @@ typedef struct {
 /*
  * Sun Jun  7 05:43:49 CEST 1998 -- Alvaro
  * More comments:
- * 1) The UUencoding prodecure is now done in a general way, avoiding the problems
+ * 1) The UUencoding procedure is now done in a general way, avoiding the problems
  * with sizes and paddings that can arise depending on the architecture. Now the
  * offsets and sizes of the elements of the unique_id_rec structure are calculated
  * in unique_id_global_init; and then used to duplicate the structure without the
@@ -123,6 +128,10 @@ typedef struct {
  * XXX: thrashing.
  */
 static unique_id_rec cur_unique_id;
+static apr_uint32_t cur_unique_counter;
+#ifdef APR_HAS_THREADS
+static int is_threaded_mpm;
+#endif
 
 /*
  * Number of elements in the structure unique_id_rec.
@@ -160,6 +169,11 @@ static int unique_id_global_init(apr_pool_t *p, apr_pool_t *plog, apr_pool_t *pt
 
 static void unique_id_child_init(apr_pool_t *p, server_rec *s)
 {
+#ifdef APR_HAS_THREADS
+    is_threaded_mpm = 0;
+    ap_mpm_query(AP_MPMQ_IS_THREADED, &is_threaded_mpm);
+#endif
+
     ap_random_insecure_bytes(&cur_unique_id.root,
                              sizeof(cur_unique_id.root));
 
@@ -168,28 +182,29 @@ static void unique_id_child_init(apr_pool_t *p, server_rec *s)
      * against restart problems, and a little less protection against a clock
      * going backwards in time.
      */
-    ap_random_insecure_bytes(&cur_unique_id.counter,
-                             sizeof(cur_unique_id.counter));
+    ap_random_insecure_bytes(&cur_unique_counter,
+                             sizeof(cur_unique_counter));
 }
 
-/* NOTE: This is *NOT* the same encoding used by base64encode ... the last two
- * characters should be + and /.  But those two characters have very special
- * meanings in URLs, and we want to make it easy to use identifiers in
- * URLs.  So we replace them with @ and -.
- */
+/* Use the base64url encoding per RFC 4648, avoiding characters which
+ * are not safe in URLs.  ### TODO: can switch to apr_encode_*. */
 static const char uuencoder[64] = {
     'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
     'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
     'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
     'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
-    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '@', '-',
+    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '-', '_',
 };
 
+#ifndef APR_UINT16_MAX
+#define APR_UINT16_MAX 0xffffu
+#endif
+
 static const char *gen_unique_id(const request_rec *r)
 {
     char *str;
     /*
-     * Buffer padded with two final bytes, used to copy the unique_id_red
+     * Buffer padded with two final bytes, used to copy the unique_id_rec
      * structure without the internal paddings that it could have.
      */
     unique_id_rec new_unique_id;
@@ -197,14 +212,24 @@ static const char *gen_unique_id(const request_rec *r)
         unique_id_rec foo;
         unsigned char pad[2];
     } paddedbuf;
+    apr_uint32_t counter;
     unsigned char *x,*y;
-    unsigned short counter;
     int i,j,k;
 
     memcpy(&new_unique_id.root, &cur_unique_id.root, ROOT_SIZE);
-    new_unique_id.counter = cur_unique_id.counter;
     new_unique_id.stamp = htonl((unsigned int)apr_time_sec(r->request_time));
     new_unique_id.thread_index = htonl((unsigned int)r->connection->id);
+#ifdef APR_HAS_THREADS
+    if (is_threaded_mpm)
+        counter = apr_atomic_inc32(&cur_unique_counter);
+    else
+#endif
+        counter = cur_unique_counter++;
+
+    /* The counter is two bytes for the uuencoded unique id, in network
+     * byte order.
+     */
+    new_unique_id.counter = htons(counter % APR_UINT16_MAX);
 
     /* we'll use a temporal buffer to avoid uuencoding the possible internal
      * paddings of the original structure */
@@ -236,11 +261,6 @@ static const char *gen_unique_id(const request_rec *r)
     }
     str[k++] = '\0';
 
-    /* and increment the identifier for the next call */
-
-    counter = ntohs(new_unique_id.counter) + 1;
-    cur_unique_id.counter = htons(counter);
-
     return str;
 }