path: root/source4/ntvfs/unixuid/vfs_unixuid.c

/* 
   Unix SMB/CIFS implementation.

   a pass-thru NTVFS module to setup a security context using unix
   uid/gid

   Copyright (C) Andrew Tridgell 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; 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"

struct unixuid_private {
	void *samctx;
	struct unix_sec_ctx *last_sec_ctx;
	struct nt_user_token *last_token;
};


/*
  map a sid to a unix uid
*/
static NTSTATUS sid_to_unixuid(struct ntvfs_module_context *ntvfs,
			       struct smbsrv_request *req, struct dom_sid *sid, uid_t *uid)
{
	struct unixuid_private *private = ntvfs->private_data;
	const char *attrs[] = { "sAMAccountName", "unixID", "unixName", "sAMAccountType", NULL };
	int ret;
	const char *s;
	void *ctx;
	struct ldb_message **res;
	const char *sidstr;
	uint_t atype;

	ctx = talloc(req, 0);
	sidstr = dom_sid_string(ctx, sid);

	ret = samdb_search(private->samctx, ctx, NULL, &res, attrs, "objectSid=%s", sidstr);
	if (ret != 1) {
		DEBUG(0,("sid_to_unixuid: unable to find sam record for sid %s\n", sidstr));
		talloc_free(ctx);
		return NT_STATUS_ACCESS_DENIED;
	}

	/* make sure its a user, not a group */
	atype = samdb_result_uint(res[0], "sAMAccountType", 0);
	if (atype && atype != ATYPE_NORMAL_ACCOUNT) {
		DEBUG(0,("sid_to_unixuid: sid %s is not ATYPE_NORMAL_ACCOUNT\n", sidstr));
		talloc_free(ctx);
		return NT_STATUS_ACCESS_DENIED;
	}

	/* first try to get the uid directly */
	s = samdb_result_string(res[0], "unixID", NULL);
	if (s != NULL) {
		*uid = strtoul(s, NULL, 0);
		talloc_free(ctx);
		return NT_STATUS_OK;
	}

	/* next try via the UnixName attribute */
	s = samdb_result_string(res[0], "unixName", NULL);
	if (s != NULL) {
		struct passwd *pwd = getpwnam(s);
		if (!pwd) {
			DEBUG(0,("unixName %s for sid %s does not exist as a local user\n", s, sidstr));
			talloc_free(ctx);
			return NT_STATUS_ACCESS_DENIED;
		}
		*uid = pwd->pw_uid;
		talloc_free(ctx);
		return NT_STATUS_OK;
	}

	/* finally try via the sAMAccountName attribute */
	s = samdb_result_string(res[0], "sAMAccountName", NULL);
	if (s != NULL) {
		struct passwd *pwd = getpwnam(s);
		if (!pwd) {
			DEBUG(0,("sAMAccountName '%s' for sid %s does not exist as a local user\n", s, sidstr));
			talloc_free(ctx);
			return NT_STATUS_ACCESS_DENIED;
		}
		*uid = pwd->pw_uid;
		talloc_free(ctx);
		return NT_STATUS_OK;
	}

	DEBUG(0,("sid_to_unixuid: no unixID, unixName or sAMAccountName for sid %s\n", sidstr));

	talloc_free(ctx);
	return NT_STATUS_ACCESS_DENIED;
}


/*
  map a sid to a unix gid
*/
static NTSTATUS sid_to_unixgid(struct ntvfs_module_context *ntvfs,
			       struct smbsrv_request *req, struct dom_sid *sid, gid_t *gid)
{
	struct unixuid_private *private = ntvfs->private_data;
	const char *attrs[] = { "sAMAccountName", "unixID", "unixName", "sAMAccountType", NULL };
	int ret;
	const char *s;
	void *ctx;
	struct ldb_message **res;
	const char *sidstr;
	uint_t atype;

	ctx = talloc(req, 0);
	sidstr = dom_sid_string(ctx, sid);

	ret = samdb_search(private->samctx, ctx, NULL, &res, attrs, "objectSid=%s", sidstr);
	if (ret != 1) {
		DEBUG(0,("sid_to_unixgid: unable to find sam record for sid %s\n", sidstr));
		talloc_free(ctx);
		return NT_STATUS_ACCESS_DENIED;
	}

	/* make sure its not a user */
	atype = samdb_result_uint(res[0], "sAMAccountType", 0);
	if (atype && atype == ATYPE_NORMAL_ACCOUNT) {
		DEBUG(0,("sid_to_unixgid: sid %s is a ATYPE_NORMAL_ACCOUNT\n", sidstr));
		talloc_free(ctx);
		return NT_STATUS_ACCESS_DENIED;
	}

	/* first try to get the gid directly */
	s = samdb_result_string(res[0], "unixID", NULL);
	if (s != NULL) {
		*gid = strtoul(s, NULL, 0);
		talloc_free(ctx);
		return NT_STATUS_OK;
	}

	/* next try via the UnixName attribute */
	s = samdb_result_string(res[0], "unixName", NULL);
	if (s != NULL) {
		struct group *grp = getgrnam(s);
		if (!grp) {
			DEBUG(0,("unixName '%s' for sid %s does not exist as a local group\n", s, sidstr));
			talloc_free(ctx);
			return NT_STATUS_ACCESS_DENIED;
		}
		*gid = grp->gr_gid;
		talloc_free(ctx);
		return NT_STATUS_OK;
	}

	/* finally try via the sAMAccountName attribute */
	s = samdb_result_string(res[0], "sAMAccountName", NULL);
	if (s != NULL) {
		struct group *grp = getgrnam(s);
		if (!grp) {
			DEBUG(0,("sAMAccountName '%s' for sid %s does not exist as a local group\n", s, sidstr));
			talloc_free(ctx);
			return NT_STATUS_ACCESS_DENIED;
		}
		*gid = grp->gr_gid;
		talloc_free(ctx);
		return NT_STATUS_OK;
	}

	DEBUG(0,("sid_to_unixgid: no unixID, unixName or sAMAccountName for sid %s\n", sidstr));

	talloc_free(ctx);
	return NT_STATUS_ACCESS_DENIED;
}

struct unix_sec_ctx {
	uid_t uid;
	gid_t gid;
	uint_t ngroups;
	gid_t *groups;
};

/*
  pull the current security context into a unix_sec_ctx
*/
static struct unix_sec_ctx *save_unix_security(TALLOC_CTX *mem_ctx)
{
	struct unix_sec_ctx *sec = talloc_p(mem_ctx, struct unix_sec_ctx);
	if (sec == NULL) {
		return NULL;
	}
	sec->uid = geteuid();
	sec->gid = getegid();
	sec->ngroups = getgroups(0, NULL);
	if (sec->ngroups == -1) {
		talloc_free(sec);
		return NULL;
	}
	sec->groups = talloc_array_p(sec, gid_t, sec->ngroups);
	if (sec->groups == NULL) {
		talloc_free(sec);
		return NULL;
	}

	if (getgroups(sec->ngroups, sec->groups) != sec->ngroups) {
		talloc_free(sec);
		return NULL;
	}

	return sec;
}

/*
  set the current security context from a unix_sec_ctx
*/
static NTSTATUS set_unix_security(struct unix_sec_ctx *sec)
{
	seteuid(0);

	if (setgroups(sec->ngroups, sec->groups) != 0) {
		return NT_STATUS_ACCESS_DENIED;
	}
	if (setegid(sec->gid) != 0) {
		return NT_STATUS_ACCESS_DENIED;
	}
	if (seteuid(sec->uid) != 0) {
		return NT_STATUS_ACCESS_DENIED;
	}
	return NT_STATUS_OK;
}

/*
  form a unix_sec_ctx from the current nt_user_token
*/
static NTSTATUS nt_token_to_unix_security(struct ntvfs_module_context *ntvfs,
					  struct smbsrv_request *req,
					  struct nt_user_token *token,
					  struct unix_sec_ctx **sec)
{
	int i;
	NTSTATUS status;
	*sec = talloc_p(req, struct unix_sec_ctx);

	/* we can't do unix security without a user and group */
	if (token->num_sids < 2) {
		return NT_STATUS_ACCESS_DENIED;
	}

	status = sid_to_unixuid(ntvfs, req, token->user_sids[0], &(*sec)->uid);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	status = sid_to_unixgid(ntvfs, req, token->user_sids[1], &(*sec)->gid);
	if (!NT_STATUS_IS_OK(status)) {
		return status;
	}

	(*sec)->ngroups = token->num_sids - 2;
	(*sec)->groups = talloc_array_p(*sec, gid_t, (*sec)->ngroups);
	if ((*sec)->groups == NULL) {
		return NT_STATUS_NO_MEMORY;
	}

	for (i=0;i<(*sec)->ngroups;i++) {
		status = sid_to_unixgid(ntvfs, req, token->user_sids[i+2], &(*sec)->groups[i]);
		if (!NT_STATUS_IS_OK(status)) {
			return status;
		}
	}

	return NT_STATUS_OK;
}

/*
  setup our unix security context according to the session authentication info
*/
static NTSTATUS unixuid_setup_security(struct ntvfs_module_context *ntvfs,
				       struct smbsrv_request *req, struct unix_sec_ctx **sec)
{
	struct unixuid_private *private = ntvfs->private_data;
	struct nt_user_token *token = req->session->session_info->nt_user_token;
	void *ctx = talloc(req, 0);
	struct unix_sec_ctx *newsec;
	NTSTATUS status;

	*sec = save_unix_security(req);
	if (*sec == NULL) {
		return NT_STATUS_NO_MEMORY;
	}

	if (req->session->session_info->nt_user_token == private->last_token) {
		newsec = private->last_sec_ctx;
	} else {
		status = nt_token_to_unix_security(ntvfs, req, token, &newsec);
		if (!NT_STATUS_IS_OK(status)) {
			talloc_free(ctx);
			return status;
		}
		if (private->last_sec_ctx) {
			talloc_free(private->last_sec_ctx);
		}
		private->last_sec_ctx = newsec;
		private->last_token = req->session->session_info->nt_user_token;
		talloc_steal(private, newsec);
	}

	status = set_unix_security(newsec);
	if (!NT_STATUS_IS_OK(status)) {
		talloc_free(ctx);
		return status;
	}

	talloc_free(ctx);

	return NT_STATUS_OK;
}

/*
  this pass through macro operates on request contexts
*/
#define PASS_THRU_REQ(ntvfs, req, op, args) do { \
	NTSTATUS status2; \
	struct unix_sec_ctx *sec; \
	status = unixuid_setup_security(ntvfs, req, &sec); \
	if (NT_STATUS_IS_OK(status)) status = ntvfs_next_##op args; \
	status2 = set_unix_security(sec); \
	if (!NT_STATUS_IS_OK(status2)) smb_panic("Unable to reset security context"); \
} while (0)



/*
  connect to a share - used when a tree_connect operation comes in.
*/
static NTSTATUS unixuid_connect(struct ntvfs_module_context *ntvfs,
				struct smbsrv_request *req, const char *sharename)
{
	struct unixuid_private *private;
	NTSTATUS status;

	private = talloc_p(req->tcon, struct unixuid_private);
	if (!private) {
		return NT_STATUS_NO_MEMORY;
	}

	private->samctx = samdb_connect(private);
	if (private->samctx == NULL) {
		return NT_STATUS_INTERNAL_DB_CORRUPTION;
	}

	ntvfs->private_data = private;
	private->last_sec_ctx = NULL;
	private->last_token = NULL;

	/* we don't use PASS_THRU_REQ here, as the connect operation runs with 
	   root privileges. This allows the backends to setup any database
	   links they might need during the connect. */
	status = ntvfs_next_connect(ntvfs, req, sharename);

	return status;
}

/*
  disconnect from a share
*/
static NTSTATUS unixuid_disconnect(struct ntvfs_module_context *ntvfs,
				   struct smbsrv_tcon *tcon)
{
	struct unixuid_private *private = ntvfs->private_data;
	NTSTATUS status;

	talloc_free(private);

	status = ntvfs_next_disconnect(ntvfs, tcon);
 
	return status;
}


/*
  delete a file
*/
static NTSTATUS unixuid_unlink(struct ntvfs_module_context *ntvfs,
			      struct smbsrv_request *req, struct smb_unlink *unl)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, unlink, (ntvfs, req, unl));

	return status;
}

/*
  ioctl interface
*/
static NTSTATUS unixuid_ioctl(struct ntvfs_module_context *ntvfs,
			     struct smbsrv_request *req, union smb_ioctl *io)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, ioctl, (ntvfs, req, io));

	return status;
}

/*
  check if a directory exists
*/
static NTSTATUS unixuid_chkpath(struct ntvfs_module_context *ntvfs,
			       struct smbsrv_request *req, struct smb_chkpath *cp)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, chkpath, (ntvfs, req, cp));

	return status;
}

/*
  return info on a pathname
*/
static NTSTATUS unixuid_qpathinfo(struct ntvfs_module_context *ntvfs,
				 struct smbsrv_request *req, union smb_fileinfo *info)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, qpathinfo, (ntvfs, req, info));

	return status;
}

/*
  query info on a open file
*/
static NTSTATUS unixuid_qfileinfo(struct ntvfs_module_context *ntvfs,
				 struct smbsrv_request *req, union smb_fileinfo *info)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, qfileinfo, (ntvfs, req, info));

	return status;
}


/*
  set info on a pathname
*/
static NTSTATUS unixuid_setpathinfo(struct ntvfs_module_context *ntvfs,
				   struct smbsrv_request *req, union smb_setfileinfo *st)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, setpathinfo, (ntvfs, req, st));

	return status;
}

/*
  open a file
*/
static NTSTATUS unixuid_open(struct ntvfs_module_context *ntvfs,
			    struct smbsrv_request *req, union smb_open *io)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, open, (ntvfs, req, io));

	return status;
}

/*
  create a directory
*/
static NTSTATUS unixuid_mkdir(struct ntvfs_module_context *ntvfs,
			     struct smbsrv_request *req, union smb_mkdir *md)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, mkdir, (ntvfs, req, md));

	return status;
}

/*
  remove a directory
*/
static NTSTATUS unixuid_rmdir(struct ntvfs_module_context *ntvfs,
			     struct smbsrv_request *req, struct smb_rmdir *rd)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, rmdir, (ntvfs, req, rd));

	return status;
}

/*
  rename a set of files
*/
static NTSTATUS unixuid_rename(struct ntvfs_module_context *ntvfs,
			      struct smbsrv_request *req, union smb_rename *ren)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, rename, (ntvfs, req, ren));

	return status;
}

/*
  copy a set of files
*/
static NTSTATUS unixuid_copy(struct ntvfs_module_context *ntvfs,
			    struct smbsrv_request *req, struct smb_copy *cp)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, copy, (ntvfs, req, cp));

	return status;
}

/*
  read from a file
*/
static NTSTATUS unixuid_read(struct ntvfs_module_context *ntvfs,
			    struct smbsrv_request *req, union smb_read *rd)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, read, (ntvfs, req, rd));

	return status;
}

/*
  write to a file
*/
static NTSTATUS unixuid_write(struct ntvfs_module_context *ntvfs,
			     struct smbsrv_request *req, union smb_write *wr)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, write, (ntvfs, req, wr));

	return status;
}

/*
  seek in a file
*/
static NTSTATUS unixuid_seek(struct ntvfs_module_context *ntvfs,
			    struct smbsrv_request *req, struct smb_seek *io)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, seek, (ntvfs, req, io));

	return status;
}

/*
  flush a file
*/
static NTSTATUS unixuid_flush(struct ntvfs_module_context *ntvfs,
			     struct smbsrv_request *req, struct smb_flush *io)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, flush, (ntvfs, req, io));

	return status;
}

/*
  close a file
*/
static NTSTATUS unixuid_close(struct ntvfs_module_context *ntvfs,
			     struct smbsrv_request *req, union smb_close *io)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, close, (ntvfs, req, io));

	return status;
}

/*
  exit - closing files
*/
static NTSTATUS unixuid_exit(struct ntvfs_module_context *ntvfs,
			    struct smbsrv_request *req)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, exit, (ntvfs, req));

	return status;
}

/*
  logoff - closing files
*/
static NTSTATUS unixuid_logoff(struct ntvfs_module_context *ntvfs,
			      struct smbsrv_request *req)
{
	struct unixuid_private *private = ntvfs->private_data;
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, logoff, (ntvfs, req));

	private->last_token = NULL;

	return status;
}

/*
  lock a byte range
*/
static NTSTATUS unixuid_lock(struct ntvfs_module_context *ntvfs,
			    struct smbsrv_request *req, union smb_lock *lck)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, lock, (ntvfs, req, lck));

	return status;
}

/*
  set info on a open file
*/
static NTSTATUS unixuid_setfileinfo(struct ntvfs_module_context *ntvfs,
				   struct smbsrv_request *req, 
				   union smb_setfileinfo *info)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, setfileinfo, (ntvfs, req, info));

	return status;
}


/*
  return filesystem space info
*/
static NTSTATUS unixuid_fsinfo(struct ntvfs_module_context *ntvfs,
			      struct smbsrv_request *req, union smb_fsinfo *fs)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, fsinfo, (ntvfs, req, fs));

	return status;
}

/*
  return print queue info
*/
static NTSTATUS unixuid_lpq(struct ntvfs_module_context *ntvfs,
			   struct smbsrv_request *req, union smb_lpq *lpq)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, lpq, (ntvfs, req, lpq));

	return status;
}

/* 
   list files in a directory matching a wildcard pattern
*/
static NTSTATUS unixuid_search_first(struct ntvfs_module_context *ntvfs,
				    struct smbsrv_request *req, union smb_search_first *io, 
				    void *search_private, 
				    BOOL (*callback)(void *, union smb_search_data *))
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, search_first, (ntvfs, req, io, search_private, callback));

	return status;
}

/* continue a search */
static NTSTATUS unixuid_search_next(struct ntvfs_module_context *ntvfs,
				   struct smbsrv_request *req, union smb_search_next *io, 
				   void *search_private, 
				   BOOL (*callback)(void *, union smb_search_data *))
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, search_next, (ntvfs, req, io, search_private, callback));

	return status;
}

/* close a search */
static NTSTATUS unixuid_search_close(struct ntvfs_module_context *ntvfs,
				    struct smbsrv_request *req, union smb_search_close *io)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, search_close, (ntvfs, req, io));

	return status;
}

/* SMBtrans - not used on file shares */
static NTSTATUS unixuid_trans(struct ntvfs_module_context *ntvfs,
			     struct smbsrv_request *req, struct smb_trans2 *trans2)
{
	NTSTATUS status;

	PASS_THRU_REQ(ntvfs, req, trans, (ntvfs, req, trans2));

	return status;
}

/*
  initialise the unixuid backend, registering ourselves with the ntvfs subsystem
 */
NTSTATUS ntvfs_unixuid_init(void)
{
	NTSTATUS ret;
	struct ntvfs_ops ops;

	ZERO_STRUCT(ops);

	/* fill in all the operations */
	ops.connect = unixuid_connect;
	ops.disconnect = unixuid_disconnect;
	ops.unlink = unixuid_unlink;
	ops.chkpath = unixuid_chkpath;
	ops.qpathinfo = unixuid_qpathinfo;
	ops.setpathinfo = unixuid_setpathinfo;
	ops.open = unixuid_open;
	ops.mkdir = unixuid_mkdir;
	ops.rmdir = unixuid_rmdir;
	ops.rename = unixuid_rename;
	ops.copy = unixuid_copy;
	ops.ioctl = unixuid_ioctl;
	ops.read = unixuid_read;
	ops.write = unixuid_write;
	ops.seek = unixuid_seek;
	ops.flush = unixuid_flush;	
	ops.close = unixuid_close;
	ops.exit = unixuid_exit;
	ops.lock = unixuid_lock;
	ops.setfileinfo = unixuid_setfileinfo;
	ops.qfileinfo = unixuid_qfileinfo;
	ops.fsinfo = unixuid_fsinfo;
	ops.lpq = unixuid_lpq;
	ops.search_first = unixuid_search_first;
	ops.search_next = unixuid_search_next;
	ops.search_close = unixuid_search_close;
	ops.trans = unixuid_trans;
	ops.logoff = unixuid_logoff;

	ops.name = "unixuid";

	/* we register under all 3 backend types, as we are not type specific */
	ops.type = NTVFS_DISK;	
	ret = register_backend("ntvfs", &ops);
	if (!NT_STATUS_IS_OK(ret)) goto failed;

	ops.type = NTVFS_PRINT;	
	ret = register_backend("ntvfs", &ops);
	if (!NT_STATUS_IS_OK(ret)) goto failed;

	ops.type = NTVFS_IPC;	
	ret = register_backend("ntvfs", &ops);
	if (!NT_STATUS_IS_OK(ret)) goto failed;
	
failed:
	return ret;
}