From b6c74c78f20929fff5c92e5277ea0a6dc0f4bc7f Mon Sep 17 00:00:00 2001
From: Morgan Weetman <address@hidden>
Date: Fri, 7 Nov 2014 18:59:45 +1100
Subject: [PATCH 1/8] find: added extended attribute predicate

* find/defs.h (typedef PREDICATEFUNCTION): added pred_xattr
* find/parser.c (parse_xattr): added function, added an entry to parse_table[]
* find/pred.c (pred_xattr): added function, added an entry to pred_table[]
* find/tree.c (costlookup[]): added pred_xattr entry
---
 find/defs.h   |  1 +
 find/parser.c | 28 ++++++++++++++++++++++++++++
 find/pred.c   | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 find/tree.c   |  1 +
 4 files changed, 86 insertions(+)

diff --git a/find/defs.h b/find/defs.h
index caccd2b..4ab1bb1 100644
--- a/find/defs.h
+++ b/find/defs.h
@@ -457,6 +457,7 @@ PREDICATEFUNCTION pred_uid;
 PREDICATEFUNCTION pred_used;
 PREDICATEFUNCTION pred_user;
 PREDICATEFUNCTION pred_writable;
+PREDICATEFUNCTION pred_xattr;
 PREDICATEFUNCTION pred_xtype;
 PREDICATEFUNCTION pred_context;
 
diff --git a/find/parser.c b/find/parser.c
index dc6c47c..bb43286 100644
--- a/find/parser.c
+++ b/find/parser.c
@@ -149,6 +149,7 @@ static bool parse_xdev          (const struct parser_table*, char *argv[], int *
 static bool parse_ignore_race   (const struct parser_table*, char *argv[], int *arg_ptr);
 static bool parse_noignore_race (const struct parser_table*, char *argv[], int *arg_ptr);
 static bool parse_warn          (const struct parser_table*, char *argv[], int *arg_ptr);
+static bool parse_xattr         (const struct parser_table*, char *argv[], int *arg_ptr);
 static bool parse_xtype         (const struct parser_table*, char *argv[], int *arg_ptr);
 static bool parse_quit          (const struct parser_table*, char *argv[], int *arg_ptr);
 static bool parse_context       (const struct parser_table*, char *argv[], int *arg_ptr);
@@ -306,6 +307,7 @@ static struct parser_table const parse_table[] =
   PARSE_TEST_NP    ("wholename",             wholename), /* GNU, replaced -path, but anyway -path will soon be in POSIX */
   {ARG_TEST,       "writable",               parse_accesscheck, pred_writable}, /* GNU, 4.3.0+ */
   PARSE_OPTION     ("xdev",                  xdev), /* POSIX */
+  PARSE_TEST       ("xattr",                 xattr),	     /* GNU */
   PARSE_TEST       ("xtype",                 xtype),	     /* GNU */
 #ifdef UNIMPLEMENTED_UNIX
   /* It's pretty ugly for find to know about archive formats.
@@ -2757,6 +2759,32 @@ parse_warn (const struct parser_table* entry, char **argv, int *arg_ptr)
 }
 
 static bool
+parse_xattr (const struct parser_table* entry, char **argv, int *arg_ptr)
+{
+  const char *name;
+  const int saved_argc = *arg_ptr;
+
+  if (collect_arg (argv, arg_ptr, &name))
+    {
+      fnmatch_sanitycheck ();
+      if (check_name_arg ("-xattr", name))
+	{
+	  struct predicate *our_pred = insert_primary (entry, name);
+	  our_pred->need_stat = our_pred->need_type = false;
+	  our_pred->args.str = name;
+	  our_pred->est_success_rate = estimate_pattern_match_rate (name, 0);
+	  return true;
+	}
+      else
+	{
+	  *arg_ptr = saved_argc; /* don't consume the invalid argument. */
+	}
+    }
+  return false;
+}
+
+
+static bool
 parse_xtype (const struct parser_table* entry, char **argv, int *arg_ptr)
 {
   return insert_type (argv, arg_ptr, entry, pred_xtype);
diff --git a/find/pred.c b/find/pred.c
index 3a89679..048e263 100644
--- a/find/pred.c
+++ b/find/pred.c
@@ -141,6 +141,7 @@ struct pred_assoc pred_table[] =
   {pred_used, "used    "},
   {pred_user, "user    "},
   {pred_writable, "writable "},
+  {pred_xattr, "xattr   "},
   {pred_xtype, "xtype   "},
   {pred_context, "context"},
   {0, "none    "}
@@ -1156,6 +1157,61 @@ pred_user (const char *pathname, struct stat *stat_buf, struct predicate *pred_p
 }
 
 bool
+pred_xattr (const char *pathname, struct stat *stat_buf, struct predicate *pred_ptr)
+{
+  (void) pathname;
+  const char *re_string = pred_ptr->args.str;
+  char empty[0];
+  char *list;
+  char *substrings;
+  ssize_t list_size;
+  int i, j;
+  bool ret = false;
+  regex_t re_pattern;
+
+  // get size of xattr list for the given path by passing an empty list
+  list_size = listxattr(pathname, empty, 0);
+
+  // allocate just enough memory to hold all xattrs
+  list = malloc(list_size);
+
+  // used to hold individual attributes (substrings)
+  // allocate same size as list just in case there's only one xattr
+  substrings = malloc(list_size);
+
+  // retrieve the list of xattrs
+  listxattr(pathname, list, list_size);
+
+  // compile regex pattern
+  if (regcomp(&re_pattern, re_string, REG_ICASE|REG_NOSUB|REG_NEWLINE) != 0) {
+    free(list);
+    free(substrings);
+    return(ret);
+  }
+
+  // break list into asciiz strings
+  for (i = 0, j = 0; i < list_size; i++) {
+    substrings[j] = list[i];
+    if (list[i] == 0) {
+      // perform regex match against substring
+      j = 0;
+      if (regexec(&re_pattern, substrings, (size_t) 0, NULL, 0) == 0) {
+        ret = true;
+      }
+      continue;
+    }
+    j++;
+  }
+
+  // clean up
+  free(list);
+  free(substrings);
+  regfree(&re_pattern);
+  return(ret);
+
+}
+
+bool
 pred_xtype (const char *pathname, struct stat *stat_buf, struct predicate *pred_ptr)
 {
   struct stat sbuf;		/* local copy, not stat_buf because we're using a different stat method */
diff --git a/find/tree.c b/find/tree.c
index 026dead..2dba99d 100644
--- a/find/tree.c
+++ b/find/tree.c
@@ -1001,6 +1001,7 @@ static struct pred_cost_lookup costlookup[] =
     { pred_used      ,  NeedsStatInfo        },
     { pred_user      ,  NeedsStatInfo        },
     { pred_writable  ,  NeedsAccessInfo      },
+    { pred_xattr     ,  NeedsNothing         },
     { pred_xtype     ,  NeedsType            } /* roughly correct unless most files are symlinks */
   };
 static int pred_table_sorted = 0;
-- 
1.9.3