/* 
 * Convert AFS acls to NT acls and vice versa.
 *
 * Copyright (C) Volker Lendecke, 2003
 *
 * 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; either 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, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include "includes.h"

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_VFS

#include <afs/stds.h>
#include <afs/afs.h>
#include <afs/auth.h>
#include <afs/venus.h>
#include <afs/prs_fs.h>

#define MAXSIZE 2048

extern DOM_SID global_sid_World;
extern DOM_SID global_sid_Builtin_Administrators;
extern DOM_SID global_sid_Builtin_Backup_Operators;
extern DOM_SID global_sid_Authenticated_Users;
extern DOM_SID global_sid_NULL;

extern int afs_syscall(int, char *, int, char *, int);

struct afs_ace {
	BOOL positive;
	char *name;
	DOM_SID sid;
	enum SID_NAME_USE type;
	uint32 rights;
	struct afs_ace *next;
};

struct afs_acl {
	TALLOC_CTX *ctx;
	int type;
	int num_aces;
	struct afs_ace *acelist;
};

struct afs_iob {
	char *in, *out;
	uint16 in_size, out_size;
};


static BOOL init_afs_acl(struct afs_acl *acl)
{
	ZERO_STRUCT(*acl);
	acl->ctx = talloc_init("afs_acl");
	if (acl->ctx == NULL) {
		DEBUG(10, ("Could not init afs_acl"));
		return False;
	}
	return True;
}

static void free_afs_acl(struct afs_acl *acl)
{
	talloc_destroy(acl->ctx);
}

static struct afs_ace *clone_afs_ace(TALLOC_CTX *mem_ctx, struct afs_ace *ace)
{
	struct afs_ace *result = talloc(mem_ctx, sizeof(struct afs_ace));

	if (result == NULL)
		return NULL;

	*result = *ace;

	result->next = NULL;
	result->name = talloc_strdup(mem_ctx, ace->name);

	if (result->name == NULL) {
		return NULL;
	}

	return result;
}
	

/* Ok, this is sort-of a hack. We assume here that we have winbind users in
 * AFS. And yet another copy of parse_domain_user.... */

static BOOL parse_domain_user(const char *domuser, fstring domain,
			      fstring user)
{
	char *p = strchr(domuser,*lp_winbind_separator());

	if (p==NULL) {
		return False;
	}

	fstrcpy(user, p+1);
	fstrcpy(domain, domuser);
	domain[PTR_DIFF(p, domuser)] = 0;
	strupper_m(domain);
	
	return True;
}

static struct afs_ace *new_afs_ace(TALLOC_CTX *mem_ctx,
				   BOOL positive,
				   const char *name, uint32 rights)
{
	DOM_SID sid;
	enum SID_NAME_USE type;
	struct afs_ace *result;

	if (strcmp(name, "system:administrators") == 0) {

		sid_copy(&sid, &global_sid_Builtin_Administrators);
		type = SID_NAME_ALIAS;

	} else if (strcmp(name, "system:anyuser") == 0) {

		sid_copy(&sid, &global_sid_World);
		type = SID_NAME_ALIAS;

	} else if (strcmp(name, "system:authuser") == 0) {

		sid_copy(&sid, &global_sid_Authenticated_Users);
		type = SID_NAME_WKN_GRP;

	} else if (strcmp(name, "system:backup") == 0) {

		sid_copy(&sid, &global_sid_Builtin_Backup_Operators);
		type = SID_NAME_ALIAS;

	} else {

		fstring user, domain;

		if (!parse_domain_user(name, domain, user)) {
			fstrcpy(user, name);
			fstrcpy(domain, lp_workgroup());
		}
		    
		if (!lookup_name(domain, user, &sid, &type)) {
			DEBUG(10, ("Could not find AFS user %s\n", name));

			sid_copy(&sid, &global_sid_NULL);
			type = SID_NAME_UNKNOWN;

		}
	}

	result = talloc(mem_ctx, sizeof(struct afs_ace));

	if (result == NULL) {
		DEBUG(0, ("Could not talloc AFS ace\n"));
		return NULL;
	}

	result->name = talloc_strdup(mem_ctx, name);
	if (result->name == NULL) {
		DEBUG(0, ("Could not talloc AFS ace name\n"));
		return NULL;
	}

	result->sid = sid;
	result->type = type;

	result->positive = positive;
	result->rights = rights;

	return result;
}

static void add_afs_ace(struct afs_acl *acl,
			BOOL positive,
			const char *name, uint32 rights)
{
	struct afs_ace *ace;

	ace = new_afs_ace(acl->ctx, positive, name, rights);

	ace->next = acl->acelist;
	acl->acelist = ace;

	acl->num_aces += 1;

	DEBUG(10, ("add_afs_ace: Added %s entry for %s with rights %d\n",
		   ace->positive?"positive":"negative",
		   ace->name, ace->rights));

	return;
}

/* AFS ACLs in string form are a long string of fields delimited with \n.
 *
 * First line:  Number of positive entries
 * Second line: Number of negative entries
 * Third and following lines: The entries themselves
 *
 * An ACE is a line of two fields, delimited by \t.
 *
 * First field:  Name
 * Second field: Rights
 */

static BOOL parse_afs_acl(struct afs_acl *acl, const char *acl_str)
{
	int nplus, nminus;
	int aces;

	char str[MAXSIZE+1];
	char *p = str;

	strncpy(str, acl_str, MAXSIZE);

	if (sscanf(p, "%d", &nplus) != 1)
		return False;

	DEBUG(10, ("Found %d positive entries\n", nplus));

	if ((p = strchr(p, '\n')) == NULL)
		return False;
	p += 1;

	if (sscanf(p, "%d", &nminus) != 1)
		return False;
	
	DEBUG(10, ("Found %d negative entries\n", nminus));

	if ((p = strchr(p, '\n')) == NULL)
		return False;
	p += 1;

	for (aces = nplus+nminus; aces > 0; aces--)
	{

		const char *name;
		uint32 rights;

		name = p;

		if ((p = strchr(p, '\t')) == NULL)
			return False;
		*p = '\0';
		p += 1;

		if (sscanf(p, "%d", &rights) != 1)
			return False;

		if ((p = strchr(p, '\n')) == NULL)
			return False;
		p += 1;

		add_afs_ace(acl, nplus>0, name, rights);

		nplus -= 1;
	}

	return True;
}

static BOOL unparse_afs_acl(struct afs_acl *acl, char *acl_str)
{
	/* TODO: String length checks!!!! */

	int positives = 0;
	int negatives = 0;
	fstring line;

	*acl_str = 0;

	struct afs_ace *ace = acl->acelist;

	while (ace != NULL) {
		if (ace->positive)
			positives++;
		else
			negatives++;
		ace = ace->next;
	}

	fstr_sprintf(line, "%d\n", positives);
	safe_strcat(acl_str, line, MAXSIZE);

	fstr_sprintf(line, "%d\n", negatives);
	safe_strcat(acl_str, line, MAXSIZE);

	ace = acl->acelist;

	while (ace != NULL) {
		fstr_sprintf(line, "%s\t%d\n", ace->name, ace->rights);
		safe_strcat(acl_str, line, MAXSIZE);
		ace = ace->next;
	}
	return True;
}

static uint32 afs_to_nt_file_rights(uint32 rights)
{
	uint32 result = 0;

	if (rights & PRSFS_READ)
		result |= FILE_READ_DATA | FILE_READ_EA | 
			FILE_EXECUTE | FILE_READ_ATTRIBUTES |
			READ_CONTROL_ACCESS | SYNCHRONIZE_ACCESS;

	if (rights & PRSFS_WRITE)
		result |= FILE_WRITE_DATA | FILE_WRITE_ATTRIBUTES |
			FILE_WRITE_EA | FILE_APPEND_DATA;

	if (rights & PRSFS_LOCK)
		result |= WRITE_OWNER_ACCESS;

	if (rights & PRSFS_DELETE)
		result |= DELETE_ACCESS;

	return result;
}

static uint32 afs_to_nt_dir_rights(uint32 rights)
{
	uint32 result = 0;

	if (rights & PRSFS_INSERT)
		result |= FILE_ADD_FILE | FILE_ADD_SUBDIRECTORY;

	if (rights & PRSFS_LOOKUP)
		result |= FILE_READ_DATA | FILE_READ_EA | 
			FILE_EXECUTE | FILE_READ_ATTRIBUTES |
			READ_CONTROL_ACCESS | SYNCHRONIZE_ACCESS;

	if (rights & PRSFS_WRITE)
		result |= FILE_WRITE_ATTRIBUTES | FILE_WRITE_DATA |
			FILE_APPEND_DATA | FILE_WRITE_EA;

	if ((rights & (PRSFS_INSERT|PRSFS_LOOKUP|PRSFS_DELETE)) ==
	    (PRSFS_INSERT|PRSFS_LOOKUP|PRSFS_DELETE))
		result |= FILE_WRITE_ATTRIBUTES | FILE_WRITE_EA |
			GENERIC_WRITE_ACCESS;

	if (rights & PRSFS_DELETE)
		result |= DELETE_ACCESS;

	if (rights & PRSFS_ADMINISTER)
		result |= FILE_DELETE_CHILD | WRITE_DAC_ACCESS |
			WRITE_OWNER_ACCESS;

	return result;
}

static uint32 nt_to_afs_dir_rights(uint32 rights)
{
	uint32 result = 0;

	if (rights & (GENERIC_ALL_ACCESS|WRITE_DAC_ACCESS)) {
		result |= PRSFS_READ | PRSFS_WRITE | PRSFS_INSERT |
			PRSFS_LOOKUP | PRSFS_DELETE | PRSFS_LOCK |
			PRSFS_ADMINISTER;
	}

	if (rights & (GENERIC_READ_ACCESS|FILE_READ_DATA)) {
		result |= PRSFS_READ | PRSFS_LOOKUP;
	}

	if (rights & (GENERIC_WRITE_ACCESS|FILE_WRITE_DATA)) {
		result |= PRSFS_WRITE | PRSFS_INSERT | PRSFS_DELETE |
			PRSFS_LOCK;
	}

	return result;
}

static size_t afs_to_nt_acl(struct afs_acl *afs_acl, 
			    struct files_struct *fsp,
			    uint32 security_info,
			    struct security_descriptor_info **ppdesc)
{
	SEC_ACE *nt_ace_list;
	DOM_SID owner_sid, group_sid;
	SEC_ACCESS mask;
	SMB_STRUCT_STAT sbuf;
	SEC_ACL *psa = NULL;
	int good_aces;
	size_t sd_size;
	TALLOC_CTX *mem_ctx = main_loop_talloc_get();

	struct afs_ace *afs_ace;

	if (fsp->is_directory || fsp->fd == -1) {
		/* Get the stat struct for the owner info. */
		if(SMB_VFS_STAT(fsp->conn,fsp->fsp_name, &sbuf) != 0) {
			return 0;
		}
	} else {
		if(SMB_VFS_FSTAT(fsp,fsp->fd,&sbuf) != 0) {
			return 0;
		}
	}

	uid_to_sid(&owner_sid, sbuf.st_uid);
	gid_to_sid(&group_sid, sbuf.st_gid);

	nt_ace_list = (SEC_ACE *)malloc(afs_acl->num_aces * sizeof(SEC_ACE));

	if (nt_ace_list == NULL)
		return 0;

	afs_ace = afs_acl->acelist;
	good_aces = 0;

	while (afs_ace != NULL) {
		uint32 nt_rights;

		if (afs_ace->type == SID_NAME_UNKNOWN) {
			DEBUG(10, ("Ignoring unknown name %s\n",
				   afs_ace->name));
			afs_ace = afs_ace->next;
			continue;
		}

		if (fsp->is_directory)
			nt_rights = afs_to_nt_dir_rights(afs_ace->rights);
		else
			nt_rights = afs_to_nt_file_rights(afs_ace->rights);

		init_sec_access(&mask, nt_rights);
		init_sec_ace(&nt_ace_list[good_aces++], &(afs_ace->sid),
			     SEC_ACE_TYPE_ACCESS_ALLOWED, mask,
			     SEC_ACE_FLAG_OBJECT_INHERIT |
			     SEC_ACE_FLAG_CONTAINER_INHERIT);
		afs_ace = afs_ace->next;
	}

	psa = make_sec_acl(mem_ctx, NT4_ACL_REVISION,
			   good_aces, nt_ace_list);
	if (psa == NULL)
		return 0;

	
	*ppdesc = make_sec_desc(mem_ctx, SEC_DESC_REVISION,
				SEC_DESC_SELF_RELATIVE,
				(security_info & OWNER_SECURITY_INFORMATION)
				? &owner_sid : NULL,
				(security_info & GROUP_SECURITY_INFORMATION)
				? &group_sid : NULL,
				NULL, psa, &sd_size);

	return sd_size;
}

static BOOL nt_to_afs_acl(uint32 security_info_sent,
			  struct security_descriptor_info *psd,
			  struct afs_acl *afs_acl)
{
	SEC_ACL *dacl;
	int i;

	/* Currently we *only* look at the dacl */

	if (((security_info_sent & DACL_SECURITY_INFORMATION) == 0) ||
	    (psd->dacl == NULL))
		return True;

	if (!init_afs_acl(afs_acl))
		return False;

	dacl = psd->dacl;

	for (i = 0; i < dacl->num_aces; i++) {
		SEC_ACE *ace = &(dacl->ace[i]);
		fstring dom_name;
		fstring name;
		enum SID_NAME_USE name_type;

		if (ace->type != SEC_ACE_TYPE_ACCESS_ALLOWED) {
			/* First cut: Only positive ACEs */
			return False;
		}

		if (sid_compare(&ace->trustee,
				&global_sid_Builtin_Administrators) == 0) {

			fstrcpy(name, "system:administrators");

		} else if (sid_compare(&ace->trustee,
				       &global_sid_World) == 0) {

			fstrcpy(name, "system:anyuser");

		} else if (sid_compare(&ace->trustee,
				       &global_sid_Authenticated_Users) == 0) {

			fstrcpy(name, "system:authuser");

		} else if (sid_compare(&ace->trustee,
				       &global_sid_Builtin_Backup_Operators)
			   == 0) {

			fstrcpy(name, "system:backup");

		} else {

			if (!lookup_sid(&ace->trustee,
					dom_name, name, &name_type)) {
				DEBUG(3, ("Could not lookup sid %s\n",
					  sid_string_static(&ace->trustee)));
				return False;
			}

			if (strcmp(dom_name, lp_workgroup()) != 0) {
				DEBUG(3, ("Got SID for domain %s, not mine\n",
					  dom_name));
				return False;
			}

			if ( (name_type == SID_NAME_USER) ||
			     (name_type == SID_NAME_DOM_GRP) ) { 
				fstring only_username;
				fstrcpy(only_username, name);
				fstr_sprintf(name, "%s%s%s",
					     dom_name, lp_winbind_separator(),
					     only_username);
				strlower_m(name);
			}
		}

		add_afs_ace(afs_acl, True, name,
			    nt_to_afs_dir_rights(ace->info.mask));
	}

	return True;
}

static BOOL afs_get_afs_acl(char *filename, struct afs_acl *acl)
{
	struct afs_iob iob;

	int ret;

	char space[MAXSIZE];

	DEBUG(5, ("afs_get_afs_acl: %s\n", filename));

	iob.in_size = 0;
	iob.out_size = MAXSIZE;
	iob.in = iob.out = space;

	ret = afs_syscall(AFSCALL_PIOCTL, filename, VIOCGETAL,
			  (char *)&iob, 0);

	if (ret) {
		DEBUG(1, ("got error from PIOCTL: %d\n", ret));
		return False;
	}

	if (!init_afs_acl(acl))
		return False;

	if (!parse_afs_acl(acl, space)) {
		DEBUG(1, ("Could not parse AFS acl\n"));
		free_afs_acl(acl);
		return False;
	}

	return True;
}

static size_t afs_get_nt_acl(struct files_struct *fsp, uint32 security_info,
			     struct security_descriptor_info **ppdesc)
{
	struct afs_acl acl;
	size_t sd_size;

	DEBUG(5, ("afs_get_nt_acl: %s\n", fsp->fsp_name));

	if (!afs_get_afs_acl(fsp->fsp_name, &acl)) {
		return 0;
	}

	sd_size = afs_to_nt_acl(&acl, fsp, security_info, ppdesc);

	free_afs_acl(&acl);

	return sd_size;
}

/* For setting an AFS ACL we have to take care of the ACEs we could
 * not properly map to SIDs. Merge all of them into the new ACL. */

static void merge_unknown_aces(struct afs_acl *src, struct afs_acl *dst)
{
	struct afs_ace *ace;

	for (ace = src->acelist; ace != NULL; ace = ace->next)
	{
		struct afs_ace *copy;

		if (ace->type != SID_NAME_UNKNOWN) {
			DEBUG(10, ("Not merging known ACE for %s\n",
				   ace->name));
			continue;
		}

		DEBUG(10, ("Merging unknown ACE for %s\n", ace->name));

		copy = clone_afs_ace(dst->ctx, ace);

		if (copy == NULL) {
			DEBUG(0, ("Could not clone ACE for %s\n", ace->name));
			continue;
		}

		copy->next = dst->acelist;
		dst->acelist = copy;
		dst->num_aces += 1;
	}
}

static BOOL afs_set_nt_acl(files_struct *fsp, uint32 security_info_sent,
			   struct security_descriptor_info *psd)
{
	struct afs_acl old_afs_acl, new_afs_acl;
	char acl_string[2049];
	struct afs_iob iob;
	int ret;

	if (!fsp->is_directory) {
		/* AFS only supports ACLs on directories... */
		return False;
	}

	if (!afs_get_afs_acl(fsp->fsp_name, &old_afs_acl)) {
		DEBUG(3, ("Could not get old ACL of %s\n", fsp->fsp_name));
		return False;
	}

	if (!nt_to_afs_acl(security_info_sent, psd, &new_afs_acl)) {
		free_afs_acl(&old_afs_acl);
		return False;
	}

	merge_unknown_aces(&old_afs_acl, &new_afs_acl);

	unparse_afs_acl(&new_afs_acl, acl_string);

	free_afs_acl(&old_afs_acl);
	free_afs_acl(&new_afs_acl);

	iob.in = acl_string;
	iob.in_size = 1+strlen(iob.in);
	iob.out = NULL;
	iob.out_size = 0;

	DEBUG(10, ("trying to set acl '%s' on file %s\n",
		   iob.in, fsp->fsp_name));

	ret = afs_syscall(AFSCALL_PIOCTL, fsp->fsp_name, VIOCSETAL,
			  (char *)&iob, 0);

	if (ret != 0) {
		DEBUG(10, ("VIOCSETAL returned %d\n", ret));
	}

	return (ret == 0);
}

static size_t afsacl_fget_nt_acl(struct vfs_handle_struct *handle,
				 struct files_struct *fsp,
				 int fd,  uint32 security_info,
				 struct security_descriptor_info **ppdesc)
{
	return afs_get_nt_acl(fsp, security_info, ppdesc);
}
static size_t afsacl_get_nt_acl(struct vfs_handle_struct *handle,
				struct files_struct *fsp,
				const char *name,  uint32 security_info,
				struct security_descriptor_info **ppdesc)
{
	return afs_get_nt_acl(fsp, security_info, ppdesc);
}

BOOL afsacl_fset_nt_acl(vfs_handle_struct *handle,
			 files_struct *fsp,
			 int fd, uint32 security_info_sent,
			 SEC_DESC *psd)
{
	return afs_set_nt_acl(fsp, security_info_sent, psd);
}

BOOL afsacl_set_nt_acl(vfs_handle_struct *handle,
		       files_struct *fsp,
		       const char *name, uint32 security_info_sent,
		       SEC_DESC *psd)
{
	return afs_set_nt_acl(fsp, security_info_sent, psd);
}

/* VFS operations structure */

static vfs_op_tuple afsacl_ops[] = {	
	{SMB_VFS_OP(afsacl_fget_nt_acl), SMB_VFS_OP_FGET_NT_ACL,
	 SMB_VFS_LAYER_TRANSPARENT},
	{SMB_VFS_OP(afsacl_get_nt_acl), SMB_VFS_OP_GET_NT_ACL,
	 SMB_VFS_LAYER_TRANSPARENT},
	{SMB_VFS_OP(afsacl_fset_nt_acl), SMB_VFS_OP_FSET_NT_ACL,
	 SMB_VFS_LAYER_TRANSPARENT},
	{SMB_VFS_OP(afsacl_set_nt_acl), SMB_VFS_OP_SET_NT_ACL,
	 SMB_VFS_LAYER_TRANSPARENT},
	{SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP}
};

NTSTATUS vfs_afsacl_init(void)
{
	return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "afsacl",
				afsacl_ops);
}