Update from Gnulib by running admin/merge-gnulib

2 files changed, 120 insertions, 1 deletions

diff --git a/lib/file-has-acl.c b/lib/file-has-acl.c
index e02f0626ad3..676523ba821 100644
--- a/lib/file-has-acl.c
+++ b/lib/file-has-acl.c
@@ -29,9 +29,97 @@
 
 #include "acl-internal.h"
 
-#if GETXATTR_WITH_POSIX_ACLS
+#if USE_ACL && GETXATTR_WITH_POSIX_ACLS
+# include <string.h>
+# include <arpa/inet.h>
 # include <sys/xattr.h>
 # include <linux/xattr.h>
+# ifndef XATTR_NAME_NFSV4_ACL
+#  define XATTR_NAME_NFSV4_ACL "system.nfs4_acl"
+# endif
+
+enum {
+  /* ACE4_ACCESS_ALLOWED_ACE_TYPE = 0x00000000, */
+  ACE4_ACCESS_DENIED_ACE_TYPE  = 0x00000001,
+  ACE4_IDENTIFIER_GROUP        = 0x00000040
+};
+
+/* Return 1 if given ACL in XDR format is non-trivial, 0 if it is trivial.
+   -1 upon failure to determine it.  Possibly change errno.  Assume that
+   the ACL is valid, except avoid undefined behavior even if invalid.
+
+   See <https://linux.die.net/man/5/nfs4_acl>.  The NFSv4 acls are
+   defined in Internet RFC 7530 and as such, every NFSv4 server
+   supporting ACLs should support NFSv4 ACLs (they differ from from
+   POSIX draft ACLs).  The ACLs can be obtained via the
+   nfsv4-acl-tools, e.g., the nfs4_getfacl command.  Gnulib provides
+   only basic support of NFSv4 ACLs, i.e., recognize trivial vs
+   nontrivial ACLs.  */
+
+static int
+acl_nfs4_nontrivial (uint32_t *xattr, ssize_t nbytes)
+{
+  enum { BYTES_PER_NETWORK_UINT = 4};
+
+  /* Grab the number of aces in the acl.  */
+  nbytes -= BYTES_PER_NETWORK_UINT;
+  if (nbytes < 0)
+    return -1;
+  uint32_t num_aces = ntohl (*xattr++);
+  if (6 < num_aces)
+    return 1;
+  int ace_found = 0;
+
+  for (int ace_n = 0; ace_n < num_aces; ace_n++)
+    {
+      /* Get the acl type and flag.  Skip the mask; it's too risky to
+         test it and it does not seem to be needed.  Get the wholen.  */
+      nbytes -= 4 * BYTES_PER_NETWORK_UINT;
+      if (nbytes < 0)
+        return -1;
+      uint32_t type = ntohl (xattr[0]);
+      uint32_t flag = ntohl (xattr[1]);
+      uint32_t wholen = ntohl (xattr[3]);
+      xattr += 4;
+      int64_t wholen4 = wholen;
+      wholen4 = ((wholen4 + (BYTES_PER_NETWORK_UINT))
+                 & ~ (BYTES_PER_NETWORK_UINT - 1));
+
+      /* Trivial ACLs have only ACE4_ACCESS_ALLOWED_ACE_TYPE or
+         ACE4_ACCESS_DENIED_ACE_TYPE.  */
+      if (ACE4_ACCESS_DENIED_ACE_TYPE < type)
+        return 1;
+
+      /* RFC 7530 says FLAG should be 0, but be generous to NetApp and
+         also accept the group flag.  */
+      if (flag & ~ACE4_IDENTIFIER_GROUP)
+        return 1;
+
+      /* Get the who string.  Check NBYTES - WHOLEN4 before storing
+         into NBYTES, to avoid truncation on conversion.  */
+      if (nbytes - wholen4 < 0)
+        return -1;
+      nbytes -= wholen4;
+
+      /* For a trivial ACL, max 6 (typically 3) ACEs, 3 allow, 3 deny.
+         Check that there is at most one ACE of each TYPE and WHO.  */
+      int who2
+        = (wholen == 6 && memcmp (xattr, "OWNER@", 6) == 0 ? 0
+           : wholen == 6 && memcmp (xattr, "GROUP@", 6) == 0 ? 2
+           : wholen == 9 && memcmp (xattr, "EVERYONE@", 9) == 0 ? 4
+           : -1);
+      if (who2 < 0)
+        return 1;
+      int ace_found_bit = 1 << (who2 | type);
+      if (ace_found & ace_found_bit)
+        return 1;
+      ace_found |= ace_found_bit;
+
+      xattr = (uint32_t *) ((char *) xattr + wholen4);
+    }
+
+  return 0;
+}
 #endif
 
 /* Return 1 if NAME has a nontrivial access control list,
@@ -51,6 +139,7 @@ file_has_acl (char const *name, struct stat const *sb)
 # if GETXATTR_WITH_POSIX_ACLS
 
       ssize_t ret;
+      int initial_errno = errno;
 
       ret = getxattr (name, XATTR_NAME_POSIX_ACL_ACCESS, NULL, 0);
       if (ret < 0 && errno == ENODATA)
@@ -68,6 +157,35 @@ file_has_acl (char const *name, struct stat const *sb)
         }
 
       if (ret < 0)
+        {
+          /* Check for NFSv4 ACLs.  The max length of a trivial
+             ACL is 6 words for owner, 6 for group, 7 for everyone,
+             all times 2 because there are both allow and deny ACEs.
+             There are 6 words for owner because of type, flag, mask,
+             wholen, "OWNER@"+pad and similarly for group; everyone is
+             another word to hold "EVERYONE@".  */
+          uint32_t xattr[2 * (6 + 6 + 7)];
+
+          ret = getxattr (name, XATTR_NAME_NFSV4_ACL, xattr, sizeof xattr);
+          if (ret < 0)
+            switch (errno)
+              {
+              case ENODATA: return 0;
+              case ERANGE : return 1; /* ACL must be nontrivial.  */
+              }
+          else
+            {
+              /* It looks like a trivial ACL, but investigate further.  */
+              ret = acl_nfs4_nontrivial (xattr, ret);
+              if (ret < 0)
+                {
+                  errno = EINVAL;
+                  return ret;
+                }
+              errno = initial_errno;
+            }
+        }
+      if (ret < 0)
         return - acl_errno_valid (errno);
       return ret;
 
diff --git a/lib/time.in.h b/lib/time.in.h
index 6aa67498f57..aba2eda8759 100644
--- a/lib/time.in.h
+++ b/lib/time.in.h
@@ -315,6 +315,7 @@ _GL_CXXALIASWARN (strptime);
 #   if !(defined __cplusplus && defined GNULIB_NAMESPACE)
 #    define ctime rpl_ctime
 #   endif
+_GL_ATTRIBUTE_DEPRECATED
 _GL_FUNCDECL_RPL (ctime, char *, (time_t const *__tp)
                                  _GL_ARG_NONNULL ((1)));
 _GL_CXXALIAS_RPL (ctime, char *, (time_t const *__tp));