[PATCH 1/2] Consolidate code to initialize nscd dataset header

[Siddhesh Poyarekar <siddhesh at redhat dot com>]

Hi,

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.

Tested x86_64 with passwd, group and netgroup queries to verify that
there are no obvious regressions resulting from this change.

Siddhesh

	* 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.

---
 nscd/aicache.c       | 27 ++++++++-------------------
 nscd/grpcache.c      | 24 ++++++++----------------
 nscd/hstcache.c      | 27 +++++++++------------------
 nscd/initgrcache.c   | 24 ++++++++----------------
 nscd/netgroupcache.c | 33 +++++++++++----------------------
 nscd/nscd-client.h   | 30 ++++++++++++++++++++++++++++++
 nscd/pwdcache.c      | 24 ++++++++----------------
 nscd/servicescache.c | 24 ++++++++----------------
 8 files changed, 90 insertions(+), 123 deletions(-)

diff --git a/nscd/aicache.c b/nscd/aicache.c
index 98d40a1..e813e3c 100644
--- a/nscd/aicache.c
+++ b/nscd/aicache.c
@@ -383,17 +383,12 @@ addhstaiX (struct database_dyn *db, int fd, request_header *req,
 	  cp = family;
 	}
 
-      /* 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;
+      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->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);
diff --git a/nscd/grpcache.c b/nscd/grpcache.c
index b5a33eb..54fab42 100644
--- a/nscd/grpcache.c
+++ b/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;
diff --git a/nscd/hstcache.c b/nscd/hstcache.c
index a79b67a..ad28fa0 100644
--- a/nscd/hstcache.c
+++ b/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;
diff --git a/nscd/initgrcache.c b/nscd/initgrcache.c
index 1bf9f0d..489edca 100644
--- a/nscd/initgrcache.c
+++ b/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;
diff --git a/nscd/netgroupcache.c b/nscd/netgroupcache.c
index 820d823..85b3fbc 100644
--- a/nscd/netgroupcache.c
+++ b/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 +532,10 @@ 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);
-  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;
+  datahead_init_pos (&dataset->head, sizeof (*dataset) + req->key_len,
+		     sizeof (innetgroup_response_header),
+		     he == NULL ? 0 : (dh->nreloads + 1), result->head.ttl);
+  /* Expire this record when the netgrent record for it expires.  */
   dataset->head.timeout = timeout;
 
   dataset->resp.version = NSCD_VERSION;
diff --git a/nscd/nscd-client.h b/nscd/nscd-client.h
index 98f77e7..c069bf6 100644
--- a/nscd/nscd-client.h
+++ b/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
diff --git a/nscd/pwdcache.c b/nscd/pwdcache.c
index fa355c3..55b997d 100644
--- a/nscd/pwdcache.c
+++ b/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;
diff --git a/nscd/servicescache.c b/nscd/servicescache.c
index 12ce9b2..e1a7289 100644
--- a/nscd/servicescache.c
+++ b/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;
-- 
1.8.3.1

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