Prepare for radical source tree reorganization.zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 474 insertions, 0 deletions

diff --git a/REORG.TODO/nscd/servicescache.c b/REORG.TODO/nscd/servicescache.c
new file mode 100644
index 0000000000..131ba6ddcc
--- /dev/null
+++ b/REORG.TODO/nscd/servicescache.c
@@ -0,0 +1,474 @@
+/* Cache handling for services lookup.
+   Copyright (C) 2007-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@drepper.com>, 2007.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published
+   by the Free Software Foundation; version 2 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, see <http://www.gnu.org/licenses/>.  */
+
+#include <alloca.h>
+#include <assert.h>
+#include <errno.h>
+#include <libintl.h>
+#include <netdb.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <sys/mman.h>
+#include <kernel-features.h>
+
+#include "nscd.h"
+#include "dbg_log.h"
+
+
+/* This is the standard reply in case the service is disabled.  */
+static const serv_response_header disabled =
+{
+  .version = NSCD_VERSION,
+  .found = -1,
+  .s_name_len = 0,
+  .s_proto_len = 0,
+  .s_aliases_cnt = 0,
+  .s_port = -1
+};
+
+/* This is the struct describing how to write this record.  */
+const struct iovec serv_iov_disabled =
+{
+  .iov_base = (void *) &disabled,
+  .iov_len = sizeof (disabled)
+};
+
+
+/* This is the standard reply in case we haven't found the dataset.  */
+static const serv_response_header notfound =
+{
+  .version = NSCD_VERSION,
+  .found = 0,
+  .s_name_len = 0,
+  .s_proto_len = 0,
+  .s_aliases_cnt = 0,
+  .s_port = -1
+};
+
+
+static time_t
+cache_addserv (struct database_dyn *db, int fd, request_header *req,
+	       const void *key, struct servent *serv, uid_t owner,
+	       struct hashentry *const he, struct datahead *dh, int errval)
+{
+  bool all_written = true;
+  ssize_t total;
+  time_t t = time (NULL);
+
+  /* We allocate all data in one memory block: the iov vector,
+     the response header and the dataset itself.  */
+  struct dataset
+  {
+    struct datahead head;
+    serv_response_header resp;
+    char strdata[0];
+  } *dataset;
+
+  assert (offsetof (struct dataset, resp) == offsetof (struct datahead, data));
+
+  time_t timeout = MAX_TIMEOUT_VALUE;
+  if (serv == NULL)
+    {
+      if (he != NULL && errval == EAGAIN)
+	{
+	  /* If we have an old record available but cannot find one
+	     now because the service is not available we keep the old
+	     record and make sure it does not get removed.  */
+	  if (reload_count != UINT_MAX)
+	    /* Do not reset the value if we never not reload the record.  */
+	    dh->nreloads = reload_count - 1;
+
+	  /* Reload with the same time-to-live value.  */
+	  timeout = dh->timeout = t + db->postimeout;
+
+	  total = 0;
+	}
+      else
+	{
+	  /* We have no data.  This means we send the standard reply for this
+	     case.  */
+	  total = sizeof (notfound);
+
+	  if (fd != -1
+	      && TEMP_FAILURE_RETRY (send (fd, &notfound, total,
+					   MSG_NOSIGNAL)) != total)
+	    all_written = false;
+
+	  /* If we have a transient error or cannot permanently store
+	     the result, so be it.  */
+	  if (errval == EAGAIN || __builtin_expect (db->negtimeout == 0, 0))
+	    {
+	      /* Mark the old entry as obsolete.  */
+	      if (dh != NULL)
+		dh->usable = false;
+	    }
+	  else if ((dataset = mempool_alloc (db, (sizeof (struct dataset)
+						  + req->key_len), 1)) != NULL)
+	    {
+	      timeout = datahead_init_neg (&dataset->head,
+					   (sizeof (struct dataset)
+					    + req->key_len), total,
+					   db->negtimeout);
+
+	      /* This is the reply.  */
+	      memcpy (&dataset->resp, &notfound, total);
+
+	      /* Copy the key data.  */
+	      memcpy (dataset->strdata, key, req->key_len);
+
+	      /* If necessary, we also propagate the data to disk.  */
+	      if (db->persistent)
+		{
+		  // XXX async OK?
+		  uintptr_t pval = (uintptr_t) dataset & ~pagesize_m1;
+		  msync ((void *) pval,
+			 ((uintptr_t) dataset & pagesize_m1)
+			 + sizeof (struct dataset) + req->key_len, MS_ASYNC);
+		}
+
+	      (void) cache_add (req->type, &dataset->strdata, req->key_len,
+				&dataset->head, true, db, owner, he == NULL);
+
+	      pthread_rwlock_unlock (&db->lock);
+
+	      /* Mark the old entry as obsolete.  */
+	      if (dh != NULL)
+		dh->usable = false;
+	    }
+	}
+    }
+  else
+    {
+      /* Determine the I/O structure.  */
+      size_t s_name_len = strlen (serv->s_name) + 1;
+      size_t s_proto_len = strlen (serv->s_proto) + 1;
+      uint32_t *s_aliases_len;
+      size_t s_aliases_cnt;
+      char *aliases;
+      char *cp;
+      size_t cnt;
+
+      /* Determine the number of aliases.  */
+      s_aliases_cnt = 0;
+      for (cnt = 0; serv->s_aliases[cnt] != NULL; ++cnt)
+	++s_aliases_cnt;
+      /* Determine the length of all aliases.  */
+      s_aliases_len = (uint32_t *) alloca (s_aliases_cnt * sizeof (uint32_t));
+      total = 0;
+      for (cnt = 0; cnt < s_aliases_cnt; ++cnt)
+	{
+	  s_aliases_len[cnt] = strlen (serv->s_aliases[cnt]) + 1;
+	  total += s_aliases_len[cnt];
+	}
+
+      total += (offsetof (struct dataset, strdata)
+		+ s_name_len
+		+ s_proto_len
+		+ s_aliases_cnt * sizeof (uint32_t));
+
+      /* If we refill the cache, first assume the reconrd did not
+	 change.  Allocate memory on the cache since it is likely
+	 discarded anyway.  If it turns out to be necessary to have a
+	 new record we can still allocate real memory.  */
+      bool alloca_used = false;
+      dataset = NULL;
+
+      if (he == NULL)
+	dataset = (struct dataset *) mempool_alloc (db, total + req->key_len,
+						    1);
+
+      if (dataset == NULL)
+	{
+	  /* We cannot permanently add the result in the moment.  But
+	     we can provide the result as is.  Store the data in some
+	     temporary memory.  */
+	  dataset = (struct dataset *) alloca (total + req->key_len);
+
+	  /* We cannot add this record to the permanent database.  */
+	  alloca_used = true;
+	}
+
+      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;
+      dataset->resp.s_name_len = s_name_len;
+      dataset->resp.s_proto_len = s_proto_len;
+      dataset->resp.s_port = serv->s_port;
+      dataset->resp.s_aliases_cnt = s_aliases_cnt;
+
+      cp = dataset->strdata;
+
+      cp = mempcpy (cp, serv->s_name, s_name_len);
+      cp = mempcpy (cp, serv->s_proto, s_proto_len);
+      cp = mempcpy (cp, s_aliases_len, s_aliases_cnt * sizeof (uint32_t));
+
+      /* Then the aliases.  */
+      aliases = cp;
+      for (cnt = 0; cnt < s_aliases_cnt; ++cnt)
+	cp = mempcpy (cp, serv->s_aliases[cnt], s_aliases_len[cnt]);
+
+      assert (cp
+	      == dataset->strdata + total - offsetof (struct dataset,
+						      strdata));
+
+      char *key_copy = memcpy (cp, key, req->key_len);
+
+      /* Now we can determine whether on refill we have to create a new
+	 record or not.  */
+      if (he != NULL)
+	{
+	  assert (fd == -1);
+
+	  if (total + req->key_len == dh->allocsize
+	      && total - offsetof (struct dataset, resp) == dh->recsize
+	      && memcmp (&dataset->resp, dh->data,
+			 dh->allocsize - offsetof (struct dataset, resp)) == 0)
+	    {
+	      /* The data has not changed.  We will just bump the
+		 timeout value.  Note that the new record has been
+		 allocated on the stack and need not be freed.  */
+	      dh->timeout = dataset->head.timeout;
+	      ++dh->nreloads;
+	    }
+	  else
+	    {
+	      /* We have to create a new record.  Just allocate
+		 appropriate memory and copy it.  */
+	      struct dataset *newp
+		= (struct dataset *) mempool_alloc (db, total + req->key_len,
+						    1);
+	      if (newp != NULL)
+		{
+		  /* Adjust pointers into the memory block.  */
+		  aliases = (char *) newp + (aliases - (char *) dataset);
+		  assert (key_copy != NULL);
+		  key_copy = (char *) newp + (key_copy - (char *) dataset);
+
+		  dataset = memcpy (newp, dataset, total + req->key_len);
+		  alloca_used = false;
+		}
+
+	      /* Mark the old record as obsolete.  */
+	      dh->usable = false;
+	    }
+	}
+      else
+	{
+	  /* We write the dataset before inserting it to the database
+	     since while inserting this thread might block and so would
+	     unnecessarily keep the receiver waiting.  */
+	  assert (fd != -1);
+
+#ifdef HAVE_SENDFILE
+	  if (__builtin_expect (db->mmap_used, 1) && !alloca_used)
+	    {
+	      assert (db->wr_fd != -1);
+	      assert ((char *) &dataset->resp > (char *) db->data);
+	      assert ((char *) dataset - (char *) db->head
+		      + total
+		      <= (sizeof (struct database_pers_head)
+			  + db->head->module * sizeof (ref_t)
+			  + db->head->data_size));
+	      ssize_t written = sendfileall (fd, db->wr_fd,
+					     (char *) &dataset->resp
+					     - (char *) db->head,
+					     dataset->head.recsize);
+	      if (written != dataset->head.recsize)
+		{
+# ifndef __ASSUME_SENDFILE
+		  if (written == -1 && errno == ENOSYS)
+		    goto use_write;
+# endif
+		  all_written = false;
+		}
+	    }
+	  else
+# ifndef __ASSUME_SENDFILE
+	  use_write:
+# endif
+#endif
+	    if (writeall (fd, &dataset->resp, dataset->head.recsize)
+		!= dataset->head.recsize)
+	      all_written = false;
+	}
+
+      /* Add the record to the database.  But only if it has not been
+	 stored on the stack.  */
+      if (! alloca_used)
+	{
+	  /* If necessary, we also propagate the data to disk.  */
+	  if (db->persistent)
+	    {
+	      // XXX async OK?
+	      uintptr_t pval = (uintptr_t) dataset & ~pagesize_m1;
+	      msync ((void *) pval,
+		     ((uintptr_t) dataset & pagesize_m1)
+		     + total + req->key_len, MS_ASYNC);
+	    }
+
+	  (void) cache_add (req->type, key_copy, req->key_len,
+			    &dataset->head, true, db, owner, he == NULL);
+
+	  pthread_rwlock_unlock (&db->lock);
+	}
+    }
+
+  if (__builtin_expect (!all_written, 0) && debug_level > 0)
+    {
+      char buf[256];
+      dbg_log (_("short write in %s: %s"),  __FUNCTION__,
+	       strerror_r (errno, buf, sizeof (buf)));
+    }
+
+  return timeout;
+}
+
+
+static int
+lookup (int type, char *key, struct servent *resultbufp, char *buffer,
+	size_t buflen, struct servent **serv)
+{
+  char *proto = strrchr (key, '/');
+  if (proto != NULL && proto != key)
+    {
+      key = strndupa (key, proto - key);
+      if (proto[1] == '\0')
+	proto = NULL;
+      else
+	++proto;
+    }
+
+  if (type == GETSERVBYNAME)
+    return __getservbyname_r (key, proto, resultbufp, buffer, buflen, serv);
+
+  assert (type == GETSERVBYPORT);
+  return __getservbyport_r (atol (key), proto, resultbufp, buffer, buflen,
+			    serv);
+}
+
+
+static time_t
+addservbyX (struct database_dyn *db, int fd, request_header *req,
+	    char *key, uid_t uid, struct hashentry *he, struct datahead *dh)
+{
+  /* Search for the entry matching the key.  Please note that we don't
+     look again in the table whether the dataset is now available.  We
+     simply insert it.  It does not matter if it is in there twice.  The
+     pruning function only will look at the timestamp.  */
+  size_t buflen = 1024;
+  char *buffer = (char *) alloca (buflen);
+  struct servent resultbuf;
+  struct servent *serv;
+  bool use_malloc = false;
+  int errval = 0;
+
+  if (__glibc_unlikely (debug_level > 0))
+    {
+      if (he == NULL)
+	dbg_log (_("Haven't found \"%s\" in services cache!"), key);
+      else
+	dbg_log (_("Reloading \"%s\" in services cache!"), key);
+    }
+
+  while (lookup (req->type, key, &resultbuf, buffer, buflen, &serv) != 0
+	 && (errval = errno) == ERANGE)
+    {
+      errno = 0;
+
+      if (__glibc_unlikely (buflen > 32768))
+	{
+	  char *old_buffer = buffer;
+	  buflen *= 2;
+	  buffer = (char *) realloc (use_malloc ? buffer : NULL, buflen);
+	  if (buffer == NULL)
+	    {
+	      /* We ran out of memory.  We cannot do anything but
+		 sending a negative response.  In reality this should
+		 never happen.  */
+	      serv = NULL;
+	      buffer = old_buffer;
+
+	      /* We set the error to indicate this is (possibly) a
+		 temporary error and that it does not mean the entry
+		 is not available at all.  */
+	      errval = EAGAIN;
+	      break;
+	    }
+	  use_malloc = true;
+	}
+      else
+	/* Allocate a new buffer on the stack.  If possible combine it
+	   with the previously allocated buffer.  */
+	buffer = (char *) extend_alloca (buffer, buflen, 2 * buflen);
+    }
+
+  time_t timeout = cache_addserv (db, fd, req, key, serv, uid, he, dh, errval);
+
+  if (use_malloc)
+    free (buffer);
+
+  return timeout;
+}
+
+
+void
+addservbyname (struct database_dyn *db, int fd, request_header *req,
+	       void *key, uid_t uid)
+{
+  addservbyX (db, fd, req, key, uid, NULL, NULL);
+}
+
+
+time_t
+readdservbyname (struct database_dyn *db, struct hashentry *he,
+		 struct datahead *dh)
+{
+  request_header req =
+    {
+      .type = GETSERVBYNAME,
+      .key_len = he->len
+    };
+
+  return addservbyX (db, -1, &req, db->data + he->key, he->owner, he, dh);
+}
+
+
+void
+addservbyport (struct database_dyn *db, int fd, request_header *req,
+	       void *key, uid_t uid)
+{
+  addservbyX (db, fd, req, key, uid, NULL, NULL);
+}
+
+
+time_t
+readdservbyport (struct database_dyn *db, struct hashentry *he,
+		 struct datahead *dh)
+{
+  request_header req =
+    {
+      .type = GETSERVBYPORT,
+      .key_len = he->len
+    };
+
+  return addservbyX (db, -1, &req, db->data + he->key, he->owner, he, dh);
+}