Consolidate code to initialize nscd dataset header

This patch consolidates the code to initialize the header of a dataset
into a single set of functions (one for positive and another for
negative datasets) primarily to reduce repetition of code.  The
secondary reason is to simplify Patch 2/2 which fixes the problem of
an uninitialized byte in the header by initializing an unused field in
the structure and hence preventing a possible data leak into the cache
file.

ChangeLog

@@ -1,3 +1,17 @@
+2014-04-30  Siddhesh Poyarekar  <siddhesh@redhat.com>
+
+	* nscd/nscd-client.h (datahead_init_common, datahead_init_pos,
+	datahead_init_neg): New functions.
+	* nscd/aicache.c (addhstaiX): Use them.
+	* nscd/grpcache.c (cache_addgr): Likewise.
+	* nscd/hstcache.c (cache_addhst): Likewise.
+	* nscd/initgrcache.c (addinitgroupsX): Likewise.
+	* nscd/netgroupcache.c (do_notfound): Likewise.
+	(addgetnetgrentX): Likewise.
+	(addinnetgrX): Likewise.
+	* nscd/pwdcache.c (cache_addpw): Likewise.
+	* nscd/servicescache.c (cache_addserv): Likewise.
+
 2014-04-30  Siddhesh Poyarekar  <siddhesh@redhat.com>
 	    Atsushi Onoe  <atsushi@onoe.org>
 

nscd/aicache.c

@@ -383,17 +383,12 @@ addhstaiX (struct database_dyn *db, int fd, request_header *req,
 	  cp = family;
 	}
 
+      timeout = datahead_init_pos (&dataset->head, total + req->key_len,
+				   total - offsetof (struct dataset, resp),
+				   he == NULL ? 0 : dh->nreloads + 1,
+				   ttl == INT32_MAX ? db->postimeout : ttl);
+
       /* Fill in the rest of the dataset.  */
-      dataset->head.allocsize = total + req->key_len;
-      dataset->head.recsize = total - offsetof (struct dataset, resp);
-      dataset->head.notfound = false;
-      dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1);
-      dataset->head.usable = true;
-
-      /* Compute the timeout time.  */
-      dataset->head.ttl = ttl == INT32_MAX ? db->postimeout : ttl;
-      timeout = dataset->head.timeout = time (NULL) + dataset->head.ttl;
-
       dataset->resp.version = NSCD_VERSION;
       dataset->resp.found = 1;
       dataset->resp.naddrs = naddrs;
@@ -528,15 +523,9 @@ next_nip:
       else if ((dataset = mempool_alloc (db, (sizeof (struct dataset)
 					      + req->key_len), 1)) != NULL)
 	{
-	  dataset->head.allocsize = sizeof (struct dataset) + req->key_len;
-	  dataset->head.recsize = total;
-	  dataset->head.notfound = true;
-	  dataset->head.nreloads = 0;
-	  dataset->head.usable = true;
-
-	  /* Compute the timeout time.  */
-	  timeout = dataset->head.timeout = time (NULL) + db->negtimeout;
-	  dataset->head.ttl = db->negtimeout;
+	  timeout = datahead_init_neg (&dataset->head,
+				       sizeof (struct dataset) + req->key_len,
+				       total, db->negtimeout);
 
 	  /* This is the reply.  */
 	  memcpy (&dataset->resp, &notfound, total);

nscd/grpcache.c

@@ -128,14 +128,10 @@ cache_addgr (struct database_dyn *db, int fd, request_header *req,
 	    }
 	  else if ((dataset = mempool_alloc (db, sizeof (struct dataset) + req->key_len, 1)) != NULL)
 	    {
-	      dataset->head.allocsize = sizeof (struct dataset) + req->key_len;
-	      dataset->head.recsize = total;
-	      dataset->head.notfound = true;
-	      dataset->head.nreloads = 0;
-	      dataset->head.usable = true;
-
-	      /* Compute the timeout time.  */
-	      timeout = dataset->head.timeout = t + db->negtimeout;
+	      timeout = datahead_init_neg (&dataset->head,
+					   (sizeof (struct dataset)
+					    + req->key_len), total,
+					   db->negtimeout);
 
 	      /* This is the reply.  */
 	      memcpy (&dataset->resp, &notfound, total);
@@ -232,14 +228,10 @@ cache_addgr (struct database_dyn *db, int fd, request_header *req,
 	  dataset_temporary = true;
 	}
 
-      dataset->head.allocsize = total + n;
-      dataset->head.recsize = total - offsetof (struct dataset, resp);
-      dataset->head.notfound = false;
-      dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1);
-      dataset->head.usable = true;
-
-      /* Compute the timeout time.  */
-      timeout = dataset->head.timeout = t + db->postimeout;
+      timeout = datahead_init_pos (&dataset->head, total + n,
+				   total - offsetof (struct dataset, resp),
+				   he == NULL ? 0 : dh->nreloads + 1,
+				   db->postimeout);
 
       dataset->resp.version = NSCD_VERSION;
       dataset->resp.found = 1;

nscd/hstcache.c

@@ -152,15 +152,11 @@ cache_addhst (struct database_dyn *db, int fd, request_header *req,
 	  else if ((dataset = mempool_alloc (db, (sizeof (struct dataset)
 						  + req->key_len), 1)) != NULL)
 	    {
-	      dataset->head.allocsize = sizeof (struct dataset) + req->key_len;
-	      dataset->head.recsize = total;
-	      dataset->head.notfound = true;
-	      dataset->head.nreloads = 0;
-	      dataset->head.usable = true;
-
-	      /* Compute the timeout time.  */
-	      dataset->head.ttl = ttl == INT32_MAX ? db->negtimeout : ttl;
-	      timeout = dataset->head.timeout = t + dataset->head.ttl;
+	      timeout = datahead_init_neg (&dataset->head,
+					   (sizeof (struct dataset)
+					    + req->key_len), total,
+					   (ttl == INT32_MAX
+					    ? db->negtimeout : ttl));
 
 	      /* This is the reply.  */
 	      memcpy (&dataset->resp, resp, total);
@@ -257,15 +253,10 @@ cache_addhst (struct database_dyn *db, int fd, request_header *req,
 	  alloca_used = true;
 	}
 
-      dataset->head.allocsize = total + req->key_len;
-      dataset->head.recsize = total - offsetof (struct dataset, resp);
-      dataset->head.notfound = false;
-      dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1);
-      dataset->head.usable = true;
-
-      /* Compute the timeout time.  */
-      dataset->head.ttl = ttl == INT32_MAX ? db->postimeout : ttl;
-      timeout = dataset->head.timeout = t + dataset->head.ttl;
+      timeout = datahead_init_pos (&dataset->head, total + req->key_len,
+				   total - offsetof (struct dataset, resp),
+				   he == NULL ? 0 : dh->nreloads + 1,
+				   ttl == INT32_MAX ? db->postimeout : ttl);
 
       dataset->resp.version = NSCD_VERSION;
       dataset->resp.found = 1;

nscd/initgrcache.c

@@ -213,14 +213,10 @@ addinitgroupsX (struct database_dyn *db, int fd, request_header *req,
 	  else if ((dataset = mempool_alloc (db, (sizeof (struct dataset)
 						  + req->key_len), 1)) != NULL)
 	    {
-	      dataset->head.allocsize = sizeof (struct dataset) + req->key_len;
-	      dataset->head.recsize = total;
-	      dataset->head.notfound = true;
-	      dataset->head.nreloads = 0;
-	      dataset->head.usable = true;
-
-	      /* Compute the timeout time.  */
-	      timeout = dataset->head.timeout = time (NULL) + db->negtimeout;
+	      timeout = datahead_init_neg (&dataset->head,
+					   (sizeof (struct dataset)
+					    + req->key_len), total,
+					   db->negtimeout);
 
 	      /* This is the reply.  */
 	      memcpy (&dataset->resp, &notfound, total);
@@ -276,14 +272,10 @@ addinitgroupsX (struct database_dyn *db, int fd, request_header *req,
 	  alloca_used = true;
 	}
 
-      dataset->head.allocsize = total + req->key_len;
-      dataset->head.recsize = total - offsetof (struct dataset, resp);
-      dataset->head.notfound = false;
-      dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1);
-      dataset->head.usable = true;
-
-      /* Compute the timeout time.  */
-      timeout = dataset->head.timeout = time (NULL) + db->postimeout;
+      timeout = datahead_init_pos (&dataset->head, total + req->key_len,
+				   total - offsetof (struct dataset, resp),
+				   he == NULL ? 0 : dh->nreloads + 1,
+				   db->postimeout);
 
       dataset->resp.version = NSCD_VERSION;
       dataset->resp.found = 1;

nscd/netgroupcache.c

@@ -90,15 +90,9 @@ do_notfound (struct database_dyn *db, int fd, request_header *req,
   /* If we cannot permanently store the result, so be it.  */
   if (dataset != NULL)
     {
-      dataset->head.allocsize = sizeof (struct dataset) + req->key_len;
-      dataset->head.recsize = total;
-      dataset->head.notfound = true;
-      dataset->head.nreloads = 0;
-      dataset->head.usable = true;
-
-      /* Compute the timeout time.  */
-      timeout = dataset->head.timeout = time (NULL) + db->negtimeout;
-      dataset->head.ttl = db->negtimeout;
+      timeout = datahead_init_neg (&dataset->head,
+				   sizeof (struct dataset) + req->key_len,
+				   total, db->negtimeout);
 
       /* This is the reply.  */
       memcpy (&dataset->resp, &notfound, total);
@@ -359,13 +353,10 @@ addgetnetgrentX (struct database_dyn *db, int fd, request_header *req,
 
   /* Fill in the dataset.  */
   dataset = (struct dataset *) buffer;
-  dataset->head.allocsize = total + req->key_len;
-  dataset->head.recsize = total - offsetof (struct dataset, resp);
-  dataset->head.notfound = false;
-  dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1);
-  dataset->head.usable = true;
-  dataset->head.ttl = db->postimeout;
-  timeout = dataset->head.timeout = time (NULL) + dataset->head.ttl;
+  timeout = datahead_init_pos (&dataset->head, total + req->key_len,
+			       total - offsetof (struct dataset, resp),
+			       he == NULL ? 0 : dh->nreloads + 1,
+			       db->postimeout);
 
   dataset->resp.version = NSCD_VERSION;
   dataset->resp.found = 1;
@@ -541,12 +532,12 @@ addinnetgrX (struct database_dyn *db, int fd, request_header *req,
       dataset = &dataset_mem;
     }
 
-  dataset->head.allocsize = sizeof (*dataset) + req->key_len;
-  dataset->head.recsize = sizeof (innetgroup_response_header);
+  datahead_init_pos (&dataset->head, sizeof (*dataset) + req->key_len,
+		     sizeof (innetgroup_response_header),
+		     he == NULL ? 0 : dh->nreloads + 1, result->head.ttl);
+  /* Set the notfound status and timeout based on the result from
+     getnetgrent.  */
   dataset->head.notfound = result->head.notfound;
-  dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1);
-  dataset->head.usable = true;
-  dataset->head.ttl = result->head.ttl;
   dataset->head.timeout = timeout;
 
   dataset->resp.version = NSCD_VERSION;

nscd/nscd-client.h

@@ -236,6 +236,36 @@ struct datahead
   } data[0];
 };
 
+static inline time_t
+datahead_init_common (struct datahead *head, nscd_ssize_t allocsize,
+		      nscd_ssize_t recsize, uint32_t ttl)
+{
+  head->allocsize = allocsize;
+  head->recsize = recsize;
+  head->usable = true;
+
+  head->ttl = ttl;
+  /* Compute the timeout time.  */
+  return head->timeout = time (NULL) + ttl;
+}
+
+static inline time_t
+datahead_init_pos (struct datahead *head, nscd_ssize_t allocsize,
+		   nscd_ssize_t recsize, uint8_t nreloads, uint32_t ttl)
+{
+  head->notfound = false;
+  head->nreloads = nreloads;
+  return datahead_init_common (head, allocsize, recsize, ttl);
+}
+
+static inline time_t
+datahead_init_neg (struct datahead *head, nscd_ssize_t allocsize,
+		   nscd_ssize_t recsize, uint32_t ttl)
+{
+  head->notfound = true;
+  head->nreloads = 0;
+  return datahead_init_common (head, allocsize, recsize, ttl);
+}
 
 /* Structure for one hash table entry.  */
 struct hashentry

nscd/pwdcache.c

@@ -135,14 +135,10 @@ cache_addpw (struct database_dyn *db, int fd, request_header *req,
 	  else if ((dataset = mempool_alloc (db, (sizeof (struct dataset)
 						  + req->key_len), 1)) != NULL)
 	    {
-	      dataset->head.allocsize = sizeof (struct dataset) + req->key_len;
-	      dataset->head.recsize = total;
-	      dataset->head.notfound = true;
-	      dataset->head.nreloads = 0;
-	      dataset->head.usable = true;
-
-	      /* Compute the timeout time.  */
-	      timeout = dataset->head.timeout = t + db->negtimeout;
+	      timeout = datahead_init_neg (&dataset->head,
+					   (sizeof (struct dataset)
+					    + req->key_len), total,
+					   db->negtimeout);
 
 	      /* This is the reply.  */
 	      memcpy (&dataset->resp, &notfound, total);
@@ -215,14 +211,10 @@ cache_addpw (struct database_dyn *db, int fd, request_header *req,
 	  alloca_used = true;
 	}
 
-      dataset->head.allocsize = total + n;
-      dataset->head.recsize = total - offsetof (struct dataset, resp);
-      dataset->head.notfound = false;
-      dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1);
-      dataset->head.usable = true;
-
-      /* Compute the timeout time.  */
-      timeout = dataset->head.timeout = t + db->postimeout;
+      timeout = datahead_init_pos (&dataset->head, total + n,
+				   total - offsetof (struct dataset, resp),
+				   he == NULL ? 0 : dh->nreloads + 1,
+				   db->postimeout);
 
       dataset->resp.version = NSCD_VERSION;
       dataset->resp.found = 1;

nscd/servicescache.c

@@ -120,14 +120,10 @@ cache_addserv (struct database_dyn *db, int fd, request_header *req,
 	  else if ((dataset = mempool_alloc (db, (sizeof (struct dataset)
 						  + req->key_len), 1)) != NULL)
 	    {
-	      dataset->head.allocsize = sizeof (struct dataset) + req->key_len;
-	      dataset->head.recsize = total;
-	      dataset->head.notfound = true;
-	      dataset->head.nreloads = 0;
-	      dataset->head.usable = true;
-
-	      /* Compute the timeout time.  */
-	      timeout = dataset->head.timeout = t + db->negtimeout;
+	      timeout = datahead_init_neg (&dataset->head,
+					   (sizeof (struct dataset)
+					    + req->key_len), total,
+					   db->negtimeout);
 
 	      /* This is the reply.  */
 	      memcpy (&dataset->resp, &notfound, total);
@@ -207,14 +203,10 @@ cache_addserv (struct database_dyn *db, int fd, request_header *req,
 	  alloca_used = true;
 	}
 
-      dataset->head.allocsize = total + req->key_len;
-      dataset->head.recsize = total - offsetof (struct dataset, resp);
-      dataset->head.notfound = false;
-      dataset->head.nreloads = he == NULL ? 0 : (dh->nreloads + 1);
-      dataset->head.usable = true;
-
-      /* Compute the timeout time.  */
-      timeout = dataset->head.timeout = t + db->postimeout;
+      timeout = datahead_init_pos (&dataset->head, total + req->key_len,
+				   total - offsetof (struct dataset, resp),
+				   he == NULL ? 0 : dh->nreloads + 1,
+				   db->postimeout);
 
       dataset->resp.version = NSCD_VERSION;
       dataset->resp.found = 1;