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, 585 insertions, 0 deletions

diff --git a/REORG.TODO/nscd/aicache.c b/REORG.TODO/nscd/aicache.c
new file mode 100644
index 0000000000..7bf4131979
--- /dev/null
+++ b/REORG.TODO/nscd/aicache.c
@@ -0,0 +1,585 @@
+/* Cache handling for host lookup.
+   Copyright (C) 2004-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2004.
+
+   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 <assert.h>
+#include <errno.h>
+#include <libintl.h>
+#include <netdb.h>
+#include <nss.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <resolv/resolv-internal.h>
+#include <resolv/res_hconf.h>
+
+#include "dbg_log.h"
+#include "nscd.h"
+#ifdef HAVE_SENDFILE
+# include <kernel-features.h>
+#endif
+
+
+typedef enum nss_status (*nss_gethostbyname4_r)
+  (const char *name, struct gaih_addrtuple **pat,
+   char *buffer, size_t buflen, int *errnop,
+   int *h_errnop, int32_t *ttlp);
+typedef enum nss_status (*nss_gethostbyname3_r)
+  (const char *name, int af, struct hostent *host,
+   char *buffer, size_t buflen, int *errnop,
+   int *h_errnop, int32_t *, char **);
+typedef enum nss_status (*nss_getcanonname_r)
+  (const char *name, char *buffer, size_t buflen, char **result,
+   int *errnop, int *h_errnop);
+
+
+static const ai_response_header notfound =
+{
+  .version = NSCD_VERSION,
+  .found = 0,
+  .naddrs = 0,
+  .addrslen = 0,
+  .canonlen = 0,
+  .error = 0
+};
+
+
+static time_t
+addhstaiX (struct database_dyn *db, int fd, request_header *req,
+	   void *key, uid_t uid, struct hashentry *const 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.  */
+
+  /* We allocate all data in one memory block: the iov vector,
+     the response header and the dataset itself.  */
+  struct dataset
+  {
+    struct datahead head;
+    ai_response_header resp;
+    char strdata[0];
+  } *dataset = NULL;
+
+  if (__glibc_unlikely (debug_level > 0))
+    {
+      if (he == NULL)
+	dbg_log (_("Haven't found \"%s\" in hosts cache!"), (char *) key);
+      else
+	dbg_log (_("Reloading \"%s\" in hosts cache!"), (char *) key);
+    }
+
+  static service_user *hosts_database;
+  service_user *nip;
+  int no_more;
+  int rc6 = 0;
+  int rc4 = 0;
+  int herrno = 0;
+
+  if (hosts_database == NULL)
+    no_more = __nss_database_lookup ("hosts", NULL,
+				     "dns [!UNAVAIL=return] files",
+				     &hosts_database);
+  else
+    no_more = 0;
+  nip = hosts_database;
+
+  /* Initialize configurations.  */
+  _res_hconf_init ();
+  if (__res_maybe_init (&_res, 0) == -1)
+    no_more = 1;
+
+  /* If we are looking for both IPv4 and IPv6 address we don't want
+     the lookup functions to automatically promote IPv4 addresses to
+     IPv6 addresses.  Currently this is decided by setting the
+     RES_USE_INET6 bit in _res.options.  */
+  int old_res_options = _res.options;
+  _res.options &= ~DEPRECATED_RES_USE_INET6;
+
+  size_t tmpbuf6len = 1024;
+  char *tmpbuf6 = alloca (tmpbuf6len);
+  size_t tmpbuf4len = 0;
+  char *tmpbuf4 = NULL;
+  int32_t ttl = INT32_MAX;
+  ssize_t total = 0;
+  char *key_copy = NULL;
+  bool alloca_used = false;
+  time_t timeout = MAX_TIMEOUT_VALUE;
+
+  while (!no_more)
+    {
+      void *cp;
+      int status[2] = { NSS_STATUS_UNAVAIL, NSS_STATUS_UNAVAIL };
+      int naddrs = 0;
+      size_t addrslen = 0;
+      char *canon = NULL;
+      size_t canonlen;
+
+      nss_gethostbyname4_r fct4 = __nss_lookup_function (nip,
+							 "gethostbyname4_r");
+      if (fct4 != NULL)
+	{
+	  struct gaih_addrtuple atmem;
+	  struct gaih_addrtuple *at;
+	  while (1)
+	    {
+	      at = &atmem;
+	      rc6 = 0;
+	      herrno = 0;
+	      status[1] = DL_CALL_FCT (fct4, (key, &at, tmpbuf6, tmpbuf6len,
+					      &rc6, &herrno, &ttl));
+	      if (rc6 != ERANGE || (herrno != NETDB_INTERNAL
+				    && herrno != TRY_AGAIN))
+		break;
+	      tmpbuf6 = extend_alloca (tmpbuf6, tmpbuf6len, 2 * tmpbuf6len);
+	    }
+
+	  if (rc6 != 0 && herrno == NETDB_INTERNAL)
+	    goto out;
+
+	  if (status[1] != NSS_STATUS_SUCCESS)
+	    goto next_nip;
+
+	  /* We found the data.  Count the addresses and the size.  */
+	  for (const struct gaih_addrtuple *at2 = at = &atmem; at2 != NULL;
+	       at2 = at2->next)
+	    {
+	      ++naddrs;
+	      /* We do not handle anything other than IPv4 and IPv6
+		 addresses.  The getaddrinfo implementation does not
+		 either so it is not worth trying to do more.  */
+	      if (at2->family == AF_INET)
+		addrslen += INADDRSZ;
+	      else if (at2->family == AF_INET6)
+		addrslen += IN6ADDRSZ;
+	    }
+	  canon = at->name;
+	  canonlen = strlen (canon) + 1;
+
+	  total = sizeof (*dataset) + naddrs + addrslen + canonlen;
+
+	  /* Now we can allocate the data structure.  If the TTL of the
+	     entry is reported as zero do not cache the entry at all.  */
+	  if (ttl != 0 && 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;
+	    }
+
+	  /* Fill in the address and address families.  */
+	  char *addrs = dataset->strdata;
+	  uint8_t *family = (uint8_t *) (addrs + addrslen);
+
+	  for (const struct gaih_addrtuple *at2 = at; at2 != NULL;
+	       at2 = at2->next)
+	    {
+	      *family++ = at2->family;
+	      if (at2->family == AF_INET)
+		addrs = mempcpy (addrs, at2->addr, INADDRSZ);
+	      else if (at2->family == AF_INET6)
+		addrs = mempcpy (addrs, at2->addr, IN6ADDRSZ);
+	    }
+
+	  cp = family;
+	}
+      else
+	{
+	  /* Prefer the function which also returns the TTL and
+	     canonical name.  */
+	  nss_gethostbyname3_r fct = __nss_lookup_function (nip,
+							    "gethostbyname3_r");
+	  if (fct == NULL)
+	    fct = __nss_lookup_function (nip, "gethostbyname2_r");
+
+	  if (fct == NULL)
+	    goto next_nip;
+
+	  struct hostent th[2];
+
+	  /* Collect IPv6 information first.  */
+	  while (1)
+	    {
+	      rc6 = 0;
+	      status[0] = DL_CALL_FCT (fct, (key, AF_INET6, &th[0], tmpbuf6,
+					     tmpbuf6len, &rc6, &herrno, &ttl,
+					     &canon));
+	      if (rc6 != ERANGE || herrno != NETDB_INTERNAL)
+		break;
+	      tmpbuf6 = extend_alloca (tmpbuf6, tmpbuf6len, 2 * tmpbuf6len);
+	    }
+
+	  if (rc6 != 0 && herrno == NETDB_INTERNAL)
+	    goto out;
+
+	  /* If the IPv6 lookup has been successful do not use the
+	     buffer used in that lookup, use a new one.  */
+	  if (status[0] == NSS_STATUS_SUCCESS && rc6 == 0)
+	    {
+	      tmpbuf4len = 512;
+	      tmpbuf4 = alloca (tmpbuf4len);
+	    }
+	  else
+	    {
+	      tmpbuf4len = tmpbuf6len;
+	      tmpbuf4 = tmpbuf6;
+	    }
+
+	  /* Next collect IPv4 information.  */
+	  while (1)
+	    {
+	      rc4 = 0;
+	      status[1] = DL_CALL_FCT (fct, (key, AF_INET, &th[1], tmpbuf4,
+					     tmpbuf4len, &rc4, &herrno,
+					     ttl == INT32_MAX ? &ttl : NULL,
+					     canon == NULL ? &canon : NULL));
+	      if (rc4 != ERANGE || herrno != NETDB_INTERNAL)
+		break;
+	      tmpbuf4 = extend_alloca (tmpbuf4, tmpbuf4len, 2 * tmpbuf4len);
+	    }
+
+	  if (rc4 != 0 && herrno == NETDB_INTERNAL)
+	    goto out;
+
+	  if (status[0] != NSS_STATUS_SUCCESS
+	      && status[1] != NSS_STATUS_SUCCESS)
+	    goto next_nip;
+
+	  /* We found the data.  Count the addresses and the size.  */
+	  for (int j = 0; j < 2; ++j)
+	    if (status[j] == NSS_STATUS_SUCCESS)
+	      for (int i = 0; th[j].h_addr_list[i] != NULL; ++i)
+		{
+		  ++naddrs;
+		  addrslen += th[j].h_length;
+		}
+
+	  if (canon == NULL)
+	    {
+	      /* Determine the canonical name.  */
+	      nss_getcanonname_r cfct;
+	      cfct = __nss_lookup_function (nip, "getcanonname_r");
+	      if (cfct != NULL)
+		{
+		  const size_t max_fqdn_len = 256;
+		  char *buf = alloca (max_fqdn_len);
+		  char *s;
+		  int rc;
+
+		  if (DL_CALL_FCT (cfct, (key, buf, max_fqdn_len, &s,
+					  &rc, &herrno))
+		      == NSS_STATUS_SUCCESS)
+		    canon = s;
+		  else
+		    /* Set to name now to avoid using gethostbyaddr.  */
+		    canon = key;
+		}
+	      else
+		{
+		  struct hostent *hstent = NULL;
+		  int herrno;
+		  struct hostent hstent_mem;
+		  void *addr;
+		  size_t addrlen;
+		  int addrfamily;
+
+		  if (status[1] == NSS_STATUS_SUCCESS)
+		    {
+		      addr = th[1].h_addr_list[0];
+		      addrlen = sizeof (struct in_addr);
+		      addrfamily = AF_INET;
+		    }
+		  else
+		    {
+		      addr = th[0].h_addr_list[0];
+		      addrlen = sizeof (struct in6_addr);
+		      addrfamily = AF_INET6;
+		    }
+
+		  size_t tmpbuflen = 512;
+		  char *tmpbuf = alloca (tmpbuflen);
+		  int rc;
+		  while (1)
+		    {
+		      rc = __gethostbyaddr2_r (addr, addrlen, addrfamily,
+					       &hstent_mem, tmpbuf, tmpbuflen,
+					       &hstent, &herrno, NULL);
+		      if (rc != ERANGE || herrno != NETDB_INTERNAL)
+			break;
+		      tmpbuf = extend_alloca (tmpbuf, tmpbuflen,
+					      tmpbuflen * 2);
+		    }
+
+		  if (rc == 0)
+		    {
+		      if (hstent != NULL)
+			canon = hstent->h_name;
+		      else
+			canon = key;
+		    }
+		}
+	    }
+
+	  canonlen = canon == NULL ? 0 : (strlen (canon) + 1);
+
+	  total = sizeof (*dataset) + naddrs + addrslen + canonlen;
+
+
+	  /* Now we can allocate the data structure.  If the TTL of the
+	     entry is reported as zero do not cache the entry at all.  */
+	  if (ttl != 0 && 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;
+	    }
+
+	  /* Fill in the address and address families.  */
+	  char *addrs = dataset->strdata;
+	  uint8_t *family = (uint8_t *) (addrs + addrslen);
+
+	  for (int j = 0; j < 2; ++j)
+	    if (status[j] == NSS_STATUS_SUCCESS)
+	      for (int i = 0; th[j].h_addr_list[i] != NULL; ++i)
+		{
+		  addrs = mempcpy (addrs, th[j].h_addr_list[i],
+				   th[j].h_length);
+		  *family++ = th[j].h_addrtype;
+		}
+
+	  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->resp.version = NSCD_VERSION;
+      dataset->resp.found = 1;
+      dataset->resp.naddrs = naddrs;
+      dataset->resp.addrslen = addrslen;
+      dataset->resp.canonlen = canonlen;
+      dataset->resp.error = NETDB_SUCCESS;
+
+      if (canon != NULL)
+	cp = mempcpy (cp, canon, canonlen);
+
+      key_copy = memcpy (cp, key, req->key_len);
+
+      assert (cp == (char *) dataset + total);
+
+      /* 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->ttl = dataset->head.ttl;
+	      ++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 (__glibc_likely (newp != NULL))
+		{
+		  /* Adjust pointer into the memory block.  */
+		  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 let the receiver wait.  */
+	  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));
+# ifndef __ASSUME_SENDFILE
+	      ssize_t written;
+	      written =
+# endif
+		sendfileall (fd, db->wr_fd, (char *) &dataset->resp
+			     - (char *) db->head, dataset->head.recsize);
+# ifndef __ASSUME_SENDFILE
+	      if (written == -1 && errno == ENOSYS)
+		goto use_write;
+# endif
+	    }
+	  else
+# ifndef __ASSUME_SENDFILE
+	  use_write:
+# endif
+#endif
+	    writeall (fd, &dataset->resp, dataset->head.recsize);
+	}
+
+      goto out;
+
+next_nip:
+      if (nss_next_action (nip, status[1]) == NSS_ACTION_RETURN)
+	break;
+
+      if (nip->next == NULL)
+	no_more = -1;
+      else
+	nip = nip->next;
+    }
+
+  /* No result found.  Create a negative result record.  */
+  if (he != NULL && rc4 == 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 && dh->nreloads == reload_count)
+	/* 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 = time (NULL) + dh->ttl;
+    }
+  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));
+
+      /* If we have a transient error or cannot permanently store the
+	 result, so be it.  */
+      if (rc4 == EAGAIN || __builtin_expect (db->negtimeout == 0, 0))
+	{
+	  /* Mark the old entry as obsolete.  */
+	  if (dh != NULL)
+	    dh->usable = false;
+	  dataset = NULL;
+	}
+      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.  */
+	  key_copy = memcpy (dataset->strdata, key, req->key_len);
+	}
+   }
+
+ out:
+  _res.options |= old_res_options & DEPRECATED_RES_USE_INET6;
+
+  if (dataset != NULL && !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, uid, he == NULL);
+
+      pthread_rwlock_unlock (&db->lock);
+
+      /* Mark the old entry as obsolete.  */
+      if (dh != NULL)
+	dh->usable = false;
+    }
+
+  return timeout;
+}
+
+
+void
+addhstai (struct database_dyn *db, int fd, request_header *req, void *key,
+	  uid_t uid)
+{
+  addhstaiX (db, fd, req, key, uid, NULL, NULL);
+}
+
+
+time_t
+readdhstai (struct database_dyn *db, struct hashentry *he, struct datahead *dh)
+{
+  request_header req =
+    {
+      .type = GETAI,
+      .key_len = he->len
+    };
+
+  return addhstaiX (db, -1, &req, db->data + he->key, he->owner, he, dh);
+}