X-Git-Url: https://gitweb.michael.orlitzky.com/?a=blobdiff_plain;f=src%2Faclq.c;h=eaeb2ede17e36d33f79925e3a6416f3a605259fa;hb=d87d053c3183ccdbfe60a3c957cffa85212131c0;hp=495196d77a33bb3c0fa7a904ec3df64dbe7eda38;hpb=b3babd5135c8683e68ce97cc76e0ec0487d4ee46;p=apply-default-acl.git

diff --git a/src/aclq.c b/src/aclq.c
index 495196d..eaeb2ed 100644
--- a/src/aclq.c
+++ b/src/aclq.c
@@ -1,50 +1,87 @@
 #include <errno.h>
+#include <libgen.h> /* dirname() */
 #include <limits.h> /* PATH_MAX */
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
 
 /* ACLs */
+#include <acl/libacl.h> /* acl_get_perm, not portable */
 #include <sys/types.h>
 #include <sys/acl.h>
 
-bool has_default_acl(const char* path) {
-  /* Return true if the given path has a default ACL, false
-     otherwise. */
-  acl_t defacl = acl_get_file(path, ACL_TYPE_DEFAULT);
-  
-  if (defacl == (acl_t)NULL) {
-    return false;
+
+mode_t get_mode(const char* path) {
+  if (path == NULL) {
+    errno = ENOENT;
+    return -1;
   }
 
-  /* Used to store the entry if it exists, even though we don't care
-     what it is. */
-  acl_entry_t dummy;
-  
-  int result = acl_get_entry(defacl, ACL_FIRST_ENTRY, &dummy);
-  
-  if (result == 1) {
-    /* There's a first entry in the default ACL. */
+  struct stat s;
+  int result = stat(path, &s);
+
+  if (result == 0) {
+    return s.st_mode;
+  }
+  else {
+    /* errno will be set already by stat() */
+    return result;
+  }
+}
+
+bool mode_has_perm(mode_t mode, int perm) {
+  if (mode & perm) {
     return true;
   }
-  else if (result == 0) {
+  else {
+    return false;
+  }
+}
+
+
+bool is_regular_file(const char* path) {
+  if (path == NULL) {
+    return false;
+  }
+
+  struct stat s;
+  int result = stat(path, &s);
+  if (result == 0) {
+    return S_ISREG(s.st_mode);
+  }
+  else {
     return false;
   }
+}
+
+bool is_directory(const char* path) {
+  if (path == NULL) {
+    return false;
+  }
+
+  struct stat s;
+  int result = stat(path, &s);
+  if (result == 0) {
+    return S_ISDIR(s.st_mode);
+  }
   else {
-    perror("has_default_acl");
     return false;
   }
 }
 
 
+int has_type_tag_acl(const char* path,
+		     acl_type_t type,
+		     acl_tag_t desired_tag) {
+  /* Returns one if the given path has a default ACL for the supplied
+     tag, zero if it doesn't, and -1 on error. */
+  acl_t defacl = acl_get_file(path, type);
 
-bool has_default_tag_acl(const char* path, acl_tag_t tag_type) {
-  /* Return true if the given path has a default ACL for the supplied
-     tag, false otherwise. */
-  acl_t defacl = acl_get_file(path, ACL_TYPE_DEFAULT);
-  
   if (defacl == (acl_t)NULL) {
-    return false;
+    return 0;
   }
 
   acl_entry_t entry;
@@ -53,137 +90,472 @@ bool has_default_tag_acl(const char* path, acl_tag_t tag_type) {
   while (result == 1) {
     acl_tag_t tag = ACL_UNDEFINED_TAG;
     int tag_result = acl_get_tag_type(entry, &tag);
-    
+
     if (tag_result == -1) {
-       perror("has_default_tag_acl");
-       return false;
+       perror("has_default_tag_acl (acl_get_tag_type)");
+       return -1;
     }
     else {
-      if (tag == tag_type) {
-	return true;
+      if (tag == desired_tag) {
+	return 1;
       }
     }
-    
+
     result = acl_get_entry(defacl, ACL_NEXT_ENTRY, &entry);
   }
-  
-  return false;
+
+  if (result == -1) {
+    perror("has_default_tag_acl (acl_get_entry)");
+    return -1;
+  }
+
+  return 0;
+}
+
+int has_default_tag_acl(const char* path, acl_tag_t desired_tag) {
+  return has_type_tag_acl(path, ACL_TYPE_DEFAULT, desired_tag);
 }
 
+int has_access_tag_acl(const char* path, acl_tag_t desired_tag) {
+  return has_type_tag_acl(path, ACL_TYPE_ACCESS, desired_tag);
+}
 
-bool has_default_user_obj_acl(const char* path) {
+int has_default_user_obj_acl(const char* path) {
   return has_default_tag_acl(path, ACL_USER_OBJ);
 }
 
-bool has_default_group_obj_acl(const char* path) {
+int has_default_group_obj_acl(const char* path) {
   return has_default_tag_acl(path, ACL_GROUP_OBJ);
 }
 
-bool has_default_other_obj_acl(const char* path) {
+int has_default_other_acl(const char* path) {
   return has_default_tag_acl(path, ACL_OTHER);
 }
 
+int has_default_mask_acl(const char* path) {
+  return has_default_tag_acl(path, ACL_MASK);
+}
+
+
+int get_type_tag_entry(const char* path,
+		       acl_type_t type,
+		       acl_tag_t desired_tag,
+		       acl_entry_t* entry) {
+    /* Returns one if successful, zero when the ACL doesn't exist, and
+     -1 on unexpected errors. */
+  acl_t defacl = acl_get_file(path, type);
 
-int get_default_tag_permset(const char* path,
-			    acl_tag_t tag_type,
-			    acl_permset_t* output_perms) {
-  /* Return true if the given path has a default ACL for the supplied
-     tag, false otherwise. */
-  acl_t defacl = acl_get_file(path, ACL_TYPE_DEFAULT);
-  
   if (defacl == (acl_t)NULL) {
     /* Follow the acl_foo convention of -1 == error. */
-    return -1;
+    return 0;
   }
 
-  acl_entry_t entry;
-  int result = acl_get_entry(defacl, ACL_FIRST_ENTRY, &entry);
+  int result = acl_get_entry(defacl, ACL_FIRST_ENTRY, entry);
 
   while (result == 1) {
     acl_tag_t tag = ACL_UNDEFINED_TAG;
-    int tag_result = acl_get_tag_type(entry, &tag);
-    
+    int tag_result = acl_get_tag_type(*entry, &tag);
+
     if (tag_result == -1) {
-       perror("get_default_tag_permset");
+       perror("get_default_tag_entry (acl_get_tag_type)");
        return -1;
     }
+
+    if (tag == desired_tag) {
+      /* We found the right tag, so return successfully. */
+      return 1;
+    }
+
+    result = acl_get_entry(defacl, ACL_NEXT_ENTRY, entry);
+  }
+
+  /* This catches both the initial acl_get_entry and the ones at the
+     end of the loop. */
+  if (result == -1) {
+    perror("get_default_tag_entry (acl_get_entry)");
+    return -1;
+  }
+
+  return 0;
+}
+
+int get_default_tag_entry(const char* path,
+			  acl_tag_t desired_tag,
+			  acl_entry_t* entry) {
+  return get_type_tag_entry(path, ACL_TYPE_DEFAULT, desired_tag, entry);
+}
+
+int get_access_tag_entry(const char* path,
+			  acl_tag_t desired_tag,
+			  acl_entry_t* entry) {
+  return get_type_tag_entry(path, ACL_TYPE_ACCESS, desired_tag, entry);
+}
+
+
+
+int get_type_tag_permset(const char* path,
+			 acl_type_t type,
+			 acl_tag_t desired_tag,
+			 acl_permset_t* output_perms) {
+  /* Returns one if successful, zero when the ACL doesn't exist, and
+     -1 on unexpected errors. */
+  acl_t defacl = acl_get_file(path, type);
+
+  if (defacl == (acl_t)NULL) {
+    /* Follow the acl_foo convention of -1 == error. */
+    return 0;
+  }
+
+  acl_entry_t entry;
+  int result = get_default_tag_entry(path, desired_tag, &entry);
+
+  if (result == 1) {
+    /* We found the right tag, now get the permset. */
+    int ps_result = acl_get_permset(entry, output_perms);
+    if (ps_result == -1) {
+      perror("get_default_tag_permset (acl_get_permset)");
+    }
+
+    if (ps_result == 0) {
+      return 1;
+    }
     else {
-      if (tag == tag_type) {
-	/* We found the right tag, now get the permset. */
-	return acl_get_permset(entry, output_perms);
-      }
+      return 0;
     }
-    
-    result = acl_get_entry(defacl, ACL_NEXT_ENTRY, &entry);
   }
-  
-  return false;
+  else {
+    return result;
+  }
+}
+
+int get_default_tag_permset(const char* path,
+			    acl_tag_t desired_tag,
+			    acl_permset_t* output_perms) {
+  return get_type_tag_permset(path, ACL_TYPE_DEFAULT, desired_tag, output_perms);
+}
+
+int get_access_tag_permset(const char* path,
+			    acl_tag_t desired_tag,
+			    acl_permset_t* output_perms) {
+  return get_type_tag_permset(path, ACL_TYPE_ACCESS, desired_tag, output_perms);
+}
+
+int has_default_tag_perm(const char* path,
+			  acl_tag_t tag,
+			  acl_perm_t perm) {
+  /* Check path to see if tag has the given perm. Returns one if it
+     does, zero if it doesn't (or there's no ACL), and -1 on unexpected
+     errors. */
+
+  if (!has_default_tag_acl(path, tag)) {
+    return 0;
+  }
+
+  acl_permset_t permset;
+  bool ps_result = get_default_tag_permset(path, tag, &permset);
+
+  if (ps_result != 1) {
+    /* Failure or error. */
+    return ps_result;
+  }
+
+  int p_result = acl_get_perm(permset, perm);
+  if (p_result == -1) {
+    perror("has_default_tag_perm (acl_get_perm)");
+  }
+
+  return p_result;
+}
+
+int remove_access_tag_perm(const char* path,
+			   acl_tag_t tag,
+			   acl_perm_t perm) {
+  /* Attempt to remove perm from tag. Returns one if successful, zero
+     if there was nothing to do, and -1 on errors. */
+  int hata = has_access_tag_acl(path, tag);
+  if (hata != 1) {
+    /* Failure or error. */
+    return hata;
+  }
+
+  acl_permset_t permset;
+  bool ps_result = get_access_tag_permset(path, tag, &permset);
+
+  if (ps_result != 1) {
+    /* Failure or error. */
+    return ps_result;
+  }
+
+  int d_result = acl_delete_perm(permset, perm);
+  if (d_result == -1) {
+    perror("remove_access_tag_perm (acl_delete_perm)");
+    return -1;
+  }
+
+  /* We've only removed perm from the permset; now we have to replace
+     the permset. */
+  acl_entry_t entry;
+  int entry_result = get_access_tag_entry(path, tag, &entry);
+
+  if (entry_result == -1) {
+    perror("remove_access_tag_perm (get_access_tag_entry)");
+    return -1;
+  }
+
+  if (entry_result == 1) {
+    /* Success. */
+    int s_result = acl_set_permset(entry, permset);
+    if (s_result == -1) {
+      perror("remove_access_tag_perm (acl_set_permset)");
+      return -1;
+    }
+
+    return 1;
+  }
+  else {
+    return 0;
+  }
+}
+
+int remove_access_group_obj_execute(const char* path) {
+  return remove_access_tag_perm(path, ACL_GROUP_OBJ, ACL_EXECUTE);
+}
+
+
+int has_default_user_obj_read(const char* path) {
+  return has_default_tag_perm(path, ACL_USER_OBJ, ACL_READ);
+}
+
+int has_default_user_obj_write(const char* path) {
+  return has_default_tag_perm(path, ACL_USER_OBJ, ACL_WRITE);
+}
+
+int has_default_user_obj_execute(const char* path) {
+  return has_default_tag_perm(path, ACL_USER_OBJ, ACL_EXECUTE);
+}
+
+int has_default_group_obj_read(const char* path) {
+  return has_default_tag_perm(path, ACL_GROUP_OBJ, ACL_READ);
+}
+
+int has_default_group_obj_write(const char* path) {
+  return has_default_tag_perm(path, ACL_GROUP_OBJ, ACL_WRITE);
+}
+
+int has_default_group_obj_execute(const char* path) {
+  return has_default_tag_perm(path, ACL_GROUP_OBJ, ACL_EXECUTE);
 }
 
-int get_default_user_obj_permset(const char* path,
-				 acl_permset_t* output_perms) {
-  return get_default_tag_permset(path, ACL_USER_OBJ, output_perms);
+int has_default_other_read(const char* path) {
+  return has_default_tag_perm(path, ACL_OTHER, ACL_READ);
 }
 
-int get_default_group_obj_permset(const char* path,
-				 acl_permset_t* output_perms) {
-  return get_default_tag_permset(path, ACL_GROUP_OBJ, output_perms);
+int has_default_other_write(const char* path) {
+  return has_default_tag_perm(path, ACL_OTHER, ACL_WRITE);
 }
 
-int get_default_other_obj_permset(const char* path,
-				 acl_permset_t* output_perms) {
-  return get_default_tag_permset(path, ACL_OTHER, output_perms);
+int has_default_other_execute(const char* path) {
+  return has_default_tag_perm(path, ACL_OTHER, ACL_EXECUTE);
+}
+
+int has_default_mask_read(const char* path) {
+  return has_default_tag_perm(path, ACL_MASK, ACL_READ);
+}
+
+int has_default_mask_write(const char* path) {
+  return has_default_tag_perm(path, ACL_MASK, ACL_WRITE);
+}
+
+int has_default_mask_execute(const char* path) {
+  return has_default_tag_perm(path, ACL_MASK, ACL_EXECUTE);
+}
+
+
+int reapply_default_acl(const char* path) {
+  /* If this is a normal file or directory (i.e. that has just been
+     created), we proceed to find its parent directory which will have
+     a default ACL.
+
+     Returns one for success, zero for failure (i.e. no ACL), and -1
+     on unexpected errors. */
+  if (path == NULL) {
+    return 0;
+  }
+
+  if (!is_regular_file(path) && !is_directory(path)) {
+    return 0;
+  }
+
+  /* dirname mangles its argument */
+  char path_copy[PATH_MAX];
+  strncpy(path_copy, path, PATH_MAX-1);
+  path_copy[PATH_MAX-1] = 0;
+
+  char* parent = dirname(path_copy);
+  if (!is_directory(parent)) {
+    /* Make sure dirname() did what we think it did. */
+    return 0;
+  }
+
+  /* This is the original mode of path. We will simply add permissions
+     to it, and then later reapply the result via chmod. */
+  mode_t path_mode = get_mode(path);
+
+  if (has_default_mask_acl(parent)) {
+    /* The parent has an extended ACL. Extended ACLs use the mask
+       entry. */
+
+    /* For the group bits, we'll use the ACL's mask instead of the group
+       object bits. If the default ACL had a group entry, it should
+       already have propagated (but might be masked). */
+    if (has_default_mask_read(parent)) {
+      path_mode |= S_IRGRP;
+    }
+    else {
+      path_mode &= ~S_IRGRP;
+    }
+
+    if (has_default_mask_write(parent)) {
+      path_mode |= S_IWGRP;
+    }
+    else {
+      path_mode &= ~S_IWGRP;
+    }
+
+    if (!mode_has_perm(path_mode, S_IXGRP)) {
+      /* The group ACL entry should already have been inherited from the
+	 default ACL. If the source was not group executable, we want to
+	 modify the destination so that it is not group executable
+	 either. In the presence of ACLs, the group permissions come not
+	 from the mode bits, but from the group:: ACL entry. So, to do
+	 this, we remove the group::x entry. */
+      remove_access_group_obj_execute(path);
+    }
+
+    /* We need to determine whether or not to mask the execute
+       bit. This applies not only to the user/group/other entries, but
+       also to all other named entries. If the original file wasn't
+       executable, then the result probably should not be. To
+       determine whether or not "it was executable", we rely on the
+       user execute bits. Obviously this should be done before we
+       twiddle that bit. */
+    if (has_default_mask_execute(parent)) {
+      if (mode_has_perm(path_mode, S_IXUSR)) {
+	/* This just adds the group execute bit, and doesn't actually
+	     grant group execute permissions. */
+	path_mode |= S_IXGRP;
+      }
+    }
+    else {
+      path_mode &= ~S_IXGRP;
+    }
+
+  }
+  else {
+    /* It's a minimal ACL. We'll repeat for the group bits what we
+       already did for the owner/other bits. */
+    if (has_default_group_obj_acl(parent)) {
+      if (has_default_group_obj_read(parent)) {
+	path_mode |= S_IRGRP;
+      }
+      else {
+	path_mode &= ~S_IRGRP;
+      }
+
+
+      if (has_default_group_obj_write(parent)) {
+	path_mode |= S_IWGRP;
+      }
+      else {
+	path_mode &= ~S_IWGRP;
+      }
+
+      /* We don't want to set the execute bit on via the ACL unless it
+	 was on originally. */
+      if (!has_default_group_obj_execute(parent)) {
+	path_mode &= ~S_IXGRP;
+      }
+    }
+  }
+
+
+  /* If parent has a default user ACL, apply it. */
+  if (has_default_user_obj_acl(parent)) {
+
+    if (has_default_user_obj_read(parent)) {
+      /* Add user read. */
+      path_mode |= S_IRUSR;
+    }
+    else {
+      /* Remove user read. */
+      path_mode &= ~S_IRUSR;
+    }
+
+
+    if (has_default_user_obj_write(parent)) {
+      /* Add user write. */
+      path_mode |= S_IWUSR;
+    }
+    else {
+      /* Remove user write. */
+      path_mode &= ~S_IWUSR;
+    }
+
+
+    /* We don't want to set the execute bit on via the ACL unless it
+       was on originally. */
+    if (!has_default_user_obj_execute(parent)) {
+      /* Remove user execute. */
+      path_mode &= ~S_IXUSR;
+    }
+  }
+
+
+  /* Do the same thing with the other perms/ACL. */
+  if (has_default_other_acl(parent)) {
+
+    if (has_default_other_read(parent)) {
+      path_mode |= S_IROTH;
+    }
+    else {
+      path_mode &= ~S_IROTH;
+    }
+
+
+    if (has_default_other_write(parent)) {
+      path_mode |= S_IWOTH;
+    }
+    else {
+      path_mode &= ~S_IWOTH;
+    }
+
+
+    /* We don't want to set the execute bit on via the ACL unless it
+       was on originally. */
+    if (!has_default_other_execute(parent)) {
+      path_mode &= ~S_IXOTH;
+    }
+  }
+
+  int chmod_result = chmod(path, path_mode);
+  if (chmod_result == 0) {
+    return 1;
+  }
+  else {
+    return 0;
+  }
 }
 
 
 int main(int argc, char* argv[]) {
    const char* target = argv[1];
-   printf("Target: %s\n", target);
-   
-   if (has_default_acl(target)) {
-     printf("Target has a default ACL.\n");
-   }
-   else {
-     printf("Target does not have a default ACL.\n");
-   }
 
-   if (has_default_user_obj_acl(target)) {
-     printf("Target has a default owner ACL.\n");
-     acl_permset_t owner_perms;
-     get_default_user_obj_permset(target, &owner_perms);
-     if (acl_get_perm(owner_perms, ACL_READ) == 1) {
-       printf("User: read\n");
-     }
-     if (acl_get_perm(owner_perms, ACL_WRITE) == 1) {
-       printf("User: write\n");
-     }
-     if (acl_get_perm(owner_perms, ACL_EXECUTE) == 1) {
-       printf("User: execute\n");
-     }
-   }
-   else {
-     printf("Target does not have a default owner ACL.\n");
-   }
-
-   if (has_default_group_obj_acl(target)) {
-     printf("Target has a default group ACL.\n");
-   }
-   else {
-     printf("Target does not have a default group ACL.\n");
-   }
+   bool result = reapply_default_acl(target);
 
-   if (has_default_other_obj_acl(target)) {
-     printf("Target has a default other ACL.\n");
+   if (result) {
+     return EXIT_SUCCESS;
    }
    else {
-     printf("Target does not have a default other ACL.\n");
+     return EXIT_FAILURE;
    }
-   /*
-   acl_permset_t group_perms;
-   get_default_group_obj_permset();
-
-   acl_permset_t other_perms;
-   get_default_other_obj_permset();
-   */
-   return EXIT_SUCCESS;
 }