samba-mirror/source3/lib/util.c

/* 
   Unix SMB/CIFS implementation.
   Samba utility functions
   Copyright (C) Andrew Tridgell 1992-1998
   Copyright (C) Jeremy Allison 2001-2007
   Copyright (C) Simo Sorce 2001
   Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2003
   Copyright (C) James Peach 2006

   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 3 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, see <http://www.gnu.org/licenses/>.
*/

#include "includes.h"
#include "system/passwd.h"
#include "system/filesys.h"
#include "util_tdb.h"
#include "ctdbd_conn.h"
#include "../lib/util/util_pw.h"
#include "messages.h"
#include "messages_dgm.h"
#include "libcli/security/security.h"
#include "serverid.h"
#include "lib/util/sys_rw.h"
#include "lib/util/sys_rw_data.h"
#include "lib/util/util_process.h"

#ifdef HAVE_SYS_PRCTL_H
#include <sys/prctl.h>
#endif

/* Max allowable allococation - 256mb - 0x10000000 */
#define MAX_ALLOC_SIZE (1024*1024*256)

#if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
#ifdef WITH_NISPLUS_HOME
#ifdef BROKEN_NISPLUS_INCLUDE_FILES
/*
 * The following lines are needed due to buggy include files
 * in Solaris 2.6 which define GROUP in both /usr/include/sys/acl.h and
 * also in /usr/include/rpcsvc/nis.h. The definitions conflict. JRA.
 * Also GROUP_OBJ is defined as 0x4 in /usr/include/sys/acl.h and as
 * an enum in /usr/include/rpcsvc/nis.h.
 */

#if defined(GROUP)
#undef GROUP
#endif

#if defined(GROUP_OBJ)
#undef GROUP_OBJ
#endif

#endif /* BROKEN_NISPLUS_INCLUDE_FILES */

#include <rpcsvc/nis.h>

#endif /* WITH_NISPLUS_HOME */
#endif /* HAVE_NETGROUP && WITH_AUTOMOUNT */

static enum protocol_types Protocol = PROTOCOL_COREPLUS;

enum protocol_types get_Protocol(void)
{
	return Protocol;
}

void set_Protocol(enum protocol_types  p)
{
	Protocol = p;
}

static enum remote_arch_types ra_type = RA_UNKNOWN;

void gfree_all( void )
{
	gfree_names();
	gfree_loadparm();
	gfree_charcnv();
	gfree_interfaces();
	gfree_debugsyms();
}

/*******************************************************************
 Check if a file exists - call vfs_file_exist for samba files.
********************************************************************/

bool file_exist_stat(const char *fname,SMB_STRUCT_STAT *sbuf,
		     bool fake_dir_create_times)
{
	SMB_STRUCT_STAT st;
	if (!sbuf)
		sbuf = &st;

	if (sys_stat(fname, sbuf, fake_dir_create_times) != 0)
		return(False);

	return((S_ISREG(sbuf->st_ex_mode)) || (S_ISFIFO(sbuf->st_ex_mode)));
}

/*******************************************************************
 Check if a unix domain socket exists - call vfs_file_exist for samba files.
********************************************************************/

bool socket_exist(const char *fname)
{
	SMB_STRUCT_STAT st;
	if (sys_stat(fname, &st, false) != 0)
		return(False);

	return S_ISSOCK(st.st_ex_mode);
}

/*******************************************************************
 Returns the size in bytes of the named given the stat struct.
********************************************************************/

uint64_t get_file_size_stat(const SMB_STRUCT_STAT *sbuf)
{
	return sbuf->st_ex_size;
}

/****************************************************************************
 Check two stats have identical dev and ino fields.
****************************************************************************/

bool check_same_dev_ino(const SMB_STRUCT_STAT *sbuf1,
                        const SMB_STRUCT_STAT *sbuf2)
{
	if (sbuf1->st_ex_dev != sbuf2->st_ex_dev ||
			sbuf1->st_ex_ino != sbuf2->st_ex_ino) {
		return false;
	}
	return true;
}

/****************************************************************************
 Check if a stat struct is identical for use.
****************************************************************************/

bool check_same_stat(const SMB_STRUCT_STAT *sbuf1,
			const SMB_STRUCT_STAT *sbuf2)
{
	if (sbuf1->st_ex_uid != sbuf2->st_ex_uid ||
			sbuf1->st_ex_gid != sbuf2->st_ex_gid ||
			!check_same_dev_ino(sbuf1, sbuf2)) {
		return false;
	}
	return true;
}

/*******************************************************************
 Show a smb message structure.
********************************************************************/

void show_msg(const char *buf)
{
	int i;
	int bcc=0;

	if (!DEBUGLVL(5))
		return;

	DEBUG(5,("size=%d\nsmb_com=0x%x\nsmb_rcls=%d\nsmb_reh=%d\nsmb_err=%d\nsmb_flg=%d\nsmb_flg2=%d\n",
			smb_len(buf),
			(int)CVAL(buf,smb_com),
			(int)CVAL(buf,smb_rcls),
			(int)CVAL(buf,smb_reh),
			(int)SVAL(buf,smb_err),
			(int)CVAL(buf,smb_flg),
			(int)SVAL(buf,smb_flg2)));
	DEBUGADD(5,("smb_tid=%d\nsmb_pid=%d\nsmb_uid=%d\nsmb_mid=%d\n",
			(int)SVAL(buf,smb_tid),
			(int)SVAL(buf,smb_pid),
			(int)SVAL(buf,smb_uid),
			(int)SVAL(buf,smb_mid)));
	DEBUGADD(5,("smt_wct=%d\n",(int)CVAL(buf,smb_wct)));

	for (i=0;i<(int)CVAL(buf,smb_wct);i++)
		DEBUGADD(5,("smb_vwv[%2d]=%5d (0x%X)\n",i,
			SVAL(buf,smb_vwv+2*i),SVAL(buf,smb_vwv+2*i)));

	bcc = (int)SVAL(buf,smb_vwv+2*(CVAL(buf,smb_wct)));

	DEBUGADD(5,("smb_bcc=%d\n",bcc));

	if (DEBUGLEVEL < 10)
		return;

	if (DEBUGLEVEL < 50)
		bcc = MIN(bcc, 512);

	dump_data(10, (const uint8_t *)smb_buf_const(buf), bcc);
}

/*******************************************************************
 Setup only the byte count for a smb message.
********************************************************************/

int set_message_bcc(char *buf,int num_bytes)
{
	int num_words = CVAL(buf,smb_wct);
	SSVAL(buf,smb_vwv + num_words*SIZEOFWORD,num_bytes);
	_smb_setlen(buf,smb_size + num_words*2 + num_bytes - 4);
	return (smb_size + num_words*2 + num_bytes);
}

/*******************************************************************
 Add a data blob to the end of a smb_buf, adjusting bcc and smb_len.
 Return the bytes added
********************************************************************/

ssize_t message_push_blob(uint8_t **outbuf, DATA_BLOB blob)
{
	size_t newlen = smb_len(*outbuf) + 4 + blob.length;
	uint8_t *tmp;

	if (!(tmp = talloc_realloc(NULL, *outbuf, uint8_t, newlen))) {
		DEBUG(0, ("talloc failed\n"));
		return -1;
	}
	*outbuf = tmp;

	memcpy(tmp + smb_len(tmp) + 4, blob.data, blob.length);
	set_message_bcc((char *)tmp, smb_buflen(tmp) + blob.length);
	return blob.length;
}

/*******************************************************************
 Reduce a file name, removing .. elements.
********************************************************************/

static char *dos_clean_name(TALLOC_CTX *ctx, const char *s)
{
	char *p = NULL;
	char *str = NULL;

	DEBUG(3,("dos_clean_name [%s]\n",s));

	/* remove any double slashes */
	str = talloc_all_string_sub(ctx, s, "\\\\", "\\");
	if (!str) {
		return NULL;
	}

	/* Remove leading .\\ characters */
	if(strncmp(str, ".\\", 2) == 0) {
		trim_string(str, ".\\", NULL);
		if(*str == 0) {
			str = talloc_strdup(ctx, ".\\");
			if (!str) {
				return NULL;
			}
		}
	}

	while ((p = strstr_m(str,"\\..\\")) != NULL) {
		char *s1;

		*p = 0;
		s1 = p+3;

		if ((p=strrchr_m(str,'\\')) != NULL) {
			*p = 0;
		} else {
			*str = 0;
		}
		str = talloc_asprintf(ctx,
				"%s%s",
				str,
				s1);
		if (!str) {
			return NULL;
		}
	}

	trim_string(str,NULL,"\\..");
	return talloc_all_string_sub(ctx, str, "\\.\\", "\\");
}

/*******************************************************************
 Reduce a file name, removing .. elements.
********************************************************************/

char *unix_clean_name(TALLOC_CTX *ctx, const char *s)
{
	char *p = NULL;
	char *str = NULL;

	DEBUG(3,("unix_clean_name [%s]\n",s));

	/* remove any double slashes */
	str = talloc_all_string_sub(ctx, s, "//","/");
	if (!str) {
		return NULL;
	}

	/* Remove leading ./ characters */
	if(strncmp(str, "./", 2) == 0) {
		trim_string(str, "./", NULL);
		if(*str == 0) {
			str = talloc_strdup(ctx, "./");
			if (!str) {
				return NULL;
			}
		}
	}

	while ((p = strstr_m(str,"/../")) != NULL) {
		char *s1;

		*p = 0;
		s1 = p+3;

		if ((p=strrchr_m(str,'/')) != NULL) {
			*p = 0;
		} else {
			*str = 0;
		}
		str = talloc_asprintf(ctx,
				"%s%s",
				str,
				s1);
		if (!str) {
			return NULL;
		}
	}

	trim_string(str,NULL,"/..");
	return talloc_all_string_sub(ctx, str, "/./", "/");
}

char *clean_name(TALLOC_CTX *ctx, const char *s)
{
	char *str = dos_clean_name(ctx, s);
	if (!str) {
		return NULL;
	}
	return unix_clean_name(ctx, str);
}

/*******************************************************************
 Write data into an fd at a given offset. Ignore seek errors.
********************************************************************/

ssize_t write_data_at_offset(int fd, const char *buffer, size_t N, off_t pos)
{
	size_t total=0;
	ssize_t ret;

	if (pos == (off_t)-1) {
		return write_data(fd, buffer, N);
	}
#if defined(HAVE_PWRITE) || defined(HAVE_PRWITE64)
	while (total < N) {
		ret = sys_pwrite(fd,buffer + total,N - total, pos);
		if (ret == -1 && errno == ESPIPE) {
			return write_data(fd, buffer + total,N - total);
		}
		if (ret == -1) {
			DEBUG(0,("write_data_at_offset: write failure. Error = %s\n", strerror(errno) ));
			return -1;
		}
		if (ret == 0) {
			return total;
		}
		total += ret;
		pos += ret;
	}
	return (ssize_t)total;
#else
	/* Use lseek and write_data. */
	if (lseek(fd, pos, SEEK_SET) == -1) {
		if (errno != ESPIPE) {
			return -1;
		}
	}
	return write_data(fd, buffer, N);
#endif
}

static int reinit_after_fork_pipe[2] = { -1, -1 };

NTSTATUS init_before_fork(void)
{
	int ret;

	ret = pipe(reinit_after_fork_pipe);
	if (ret == -1) {
		NTSTATUS status;

		status = map_nt_error_from_unix_common(errno);

		DEBUG(0, ("Error creating child_pipe: %s\n",
			  nt_errstr(status)));

		return status;
	}

	return NT_STATUS_OK;
}

/**
 * Detect died parent by detecting EOF on the pipe
 */
static void reinit_after_fork_pipe_handler(struct tevent_context *ev,
					   struct tevent_fd *fde,
					   uint16_t flags,
					   void *private_data)
{
	char c;

	if (sys_read(reinit_after_fork_pipe[0], &c, 1) != 1) {
		/*
		 * we have reached EOF on stdin, which means the
		 * parent has exited. Shutdown the server
		 */
		(void)kill(getpid(), SIGTERM);
	}
}


NTSTATUS reinit_after_fork(struct messaging_context *msg_ctx,
			   struct tevent_context *ev_ctx,
			   bool parent_longlived,
			   const char *comment)
{
	NTSTATUS status = NT_STATUS_OK;

	if (reinit_after_fork_pipe[1] != -1) {
		close(reinit_after_fork_pipe[1]);
		reinit_after_fork_pipe[1] = -1;
	}

	/* tdb needs special fork handling */
	if (tdb_reopen_all(parent_longlived ? 1 : 0) != 0) {
		DEBUG(0,("tdb_reopen_all failed.\n"));
		status = NT_STATUS_OPEN_FAILED;
		goto done;
	}

	if (ev_ctx != NULL) {
		tevent_set_trace_callback(ev_ctx, NULL, NULL);
		if (tevent_re_initialise(ev_ctx) != 0) {
			smb_panic(__location__ ": Failed to re-initialise event context");
		}
	}

	if (reinit_after_fork_pipe[0] != -1) {
		struct tevent_fd *fde;

		fde = tevent_add_fd(ev_ctx, ev_ctx /* TALLOC_CTX */,
				    reinit_after_fork_pipe[0], TEVENT_FD_READ,
				    reinit_after_fork_pipe_handler, NULL);
		if (fde == NULL) {
			smb_panic(__location__ ": Failed to add reinit_after_fork pipe event");
		}
	}

	if (msg_ctx) {
		/*
		 * For clustering, we need to re-init our ctdbd connection after the
		 * fork
		 */
		status = messaging_reinit(msg_ctx);
		if (!NT_STATUS_IS_OK(status)) {
			DEBUG(0,("messaging_reinit() failed: %s\n",
				 nt_errstr(status)));
		}
	}

	if (comment) {
		prctl_set_comment(comment);
	}

 done:
	return status;
}

/****************************************************************************
 (Hopefully) efficient array append.
****************************************************************************/

void add_to_large_array(TALLOC_CTX *mem_ctx, size_t element_size,
			void *element, void *_array, uint32_t *num_elements,
			ssize_t *array_size)
{
	void **array = (void **)_array;

	if (*array_size < 0) {
		return;
	}

	if (*array == NULL) {
		if (*array_size == 0) {
			*array_size = 128;
		}

		if (*array_size >= MAX_ALLOC_SIZE/element_size) {
			goto error;
		}

		*array = TALLOC(mem_ctx, element_size * (*array_size));
		if (*array == NULL) {
			goto error;
		}
	}

	if (*num_elements == *array_size) {
		*array_size *= 2;

		if (*array_size >= MAX_ALLOC_SIZE/element_size) {
			goto error;
		}

		*array = TALLOC_REALLOC(mem_ctx, *array,
					element_size * (*array_size));

		if (*array == NULL) {
			goto error;
		}
	}

	memcpy((char *)(*array) + element_size*(*num_elements),
	       element, element_size);
	*num_elements += 1;

	return;

 error:
	*num_elements = 0;
	*array_size = -1;
}

/****************************************************************************
 Get my own domain name, or "" if we have none.
****************************************************************************/

char *get_mydnsdomname(TALLOC_CTX *ctx)
{
	const char *domname;
	char *p;

	domname = get_mydnsfullname();
	if (!domname) {
		return NULL;
	}

	p = strchr_m(domname, '.');
	if (p) {
		p++;
		return talloc_strdup(ctx, p);
	} else {
		return talloc_strdup(ctx, "");
	}
}

#if (defined(HAVE_NETGROUP) && defined(WITH_AUTOMOUNT))
/******************************************************************
 Remove any mount options such as -rsize=2048,wsize=2048 etc.
 Based on a fix from <Thomas.Hepper@icem.de>.
 Returns a malloc'ed string.
*******************************************************************/

static char *strip_mount_options(TALLOC_CTX *ctx, const char *str)
{
	if (*str == '-') {
		const char *p = str;
		while(*p && !isspace(*p))
			p++;
		while(*p && isspace(*p))
			p++;
		if(*p) {
			return talloc_strdup(ctx, p);
		}
	}
	return NULL;
}

/*******************************************************************
 Patch from jkf@soton.ac.uk
 Split Luke's automount_server into YP lookup and string splitter
 so can easily implement automount_path().
 Returns a malloc'ed string.
*******************************************************************/

#ifdef WITH_NISPLUS_HOME
char *automount_lookup(TALLOC_CTX *ctx, const char *user_name)
{
	char *value = NULL;

	char *nis_map = (char *)lp_homedir_map();

	char buffer[NIS_MAXATTRVAL + 1];
	nis_result *result;
	nis_object *object;
	entry_obj  *entry;

	snprintf(buffer, sizeof(buffer), "[key=%s],%s", user_name, nis_map);
	DEBUG(5, ("NIS+ querystring: %s\n", buffer));

	if (result = nis_list(buffer, FOLLOW_PATH|EXPAND_NAME|HARD_LOOKUP, NULL, NULL)) {
		if (result->status != NIS_SUCCESS) {
			DEBUG(3, ("NIS+ query failed: %s\n", nis_sperrno(result->status)));
		} else {
			object = result->objects.objects_val;
			if (object->zo_data.zo_type == ENTRY_OBJ) {
				entry = &object->zo_data.objdata_u.en_data;
				DEBUG(5, ("NIS+ entry type: %s\n", entry->en_type));
				DEBUG(3, ("NIS+ result: %s\n", entry->en_cols.en_cols_val[1].ec_value.ec_value_val));

				value = talloc_strdup(ctx,
						entry->en_cols.en_cols_val[1].ec_value.ec_value_val);
				if (!value) {
					nis_freeresult(result);
					return NULL;
				}
				value = talloc_string_sub(ctx,
						value,
						"&",
						user_name);
			}
		}
	}
	nis_freeresult(result);

	if (value) {
		value = strip_mount_options(ctx, value);
		DEBUG(4, ("NIS+ Lookup: %s resulted in %s\n",
					user_name, value));
	}
	return value;
}
#else /* WITH_NISPLUS_HOME */

char *automount_lookup(TALLOC_CTX *ctx, const char *user_name)
{
	char *value = NULL;

	int nis_error;        /* returned by yp all functions */
	char *nis_result;     /* yp_match inits this */
	int nis_result_len;  /* and set this */
	char *nis_domain;     /* yp_get_default_domain inits this */
	char *nis_map = lp_homedir_map(talloc_tos());

	if ((nis_error = yp_get_default_domain(&nis_domain)) != 0) {
		DEBUG(3, ("YP Error: %s\n", yperr_string(nis_error)));
		return NULL;
	}

	DEBUG(5, ("NIS Domain: %s\n", nis_domain));

	if ((nis_error = yp_match(nis_domain, nis_map, user_name,
					strlen(user_name), &nis_result,
					&nis_result_len)) == 0) {
		if (nis_result_len > 0 && nis_result[nis_result_len] == '\n') {
			nis_result[nis_result_len] = '\0';
		}
		value = talloc_strdup(ctx, nis_result);
		if (!value) {
			return NULL;
		}
		value = strip_mount_options(ctx, value);
	} else if(nis_error == YPERR_KEY) {
		DEBUG(3, ("YP Key not found:  while looking up \"%s\" in map \"%s\"\n", 
				user_name, nis_map));
		DEBUG(3, ("using defaults for server and home directory\n"));
	} else {
		DEBUG(3, ("YP Error: \"%s\" while looking up \"%s\" in map \"%s\"\n", 
				yperr_string(nis_error), user_name, nis_map));
	}

	if (value) {
		DEBUG(4, ("YP Lookup: %s resulted in %s\n", user_name, value));
	}
	return value;
}
#endif /* WITH_NISPLUS_HOME */
#endif

bool process_exists(const struct server_id pid)
{
	return serverid_exists(&pid);
}

/*******************************************************************
 Convert a uid into a user name.
********************************************************************/

const char *uidtoname(uid_t uid)
{
	TALLOC_CTX *ctx = talloc_tos();
	char *name = NULL;
	struct passwd *pass = NULL;

	pass = getpwuid_alloc(ctx,uid);
	if (pass) {
		name = talloc_strdup(ctx,pass->pw_name);
		TALLOC_FREE(pass);
	} else {
		name = talloc_asprintf(ctx,
				"%ld",
				(long int)uid);
	}
	return name;
}

/*******************************************************************
 Convert a gid into a group name.
********************************************************************/

char *gidtoname(gid_t gid)
{
	struct group *grp;

	grp = getgrgid(gid);
	if (grp) {
		return talloc_strdup(talloc_tos(), grp->gr_name);
	}
	else {
		return talloc_asprintf(talloc_tos(),
					"%d",
					(int)gid);
	}
}

/*******************************************************************
 Convert a user name into a uid.
********************************************************************/

uid_t nametouid(const char *name)
{
	struct passwd *pass;
	char *p;
	uid_t u;

	pass = Get_Pwnam_alloc(talloc_tos(), name);
	if (pass) {
		u = pass->pw_uid;
		TALLOC_FREE(pass);
		return u;
	}

	u = (uid_t)strtol(name, &p, 0);
	if ((p != name) && (*p == '\0'))
		return u;

	return (uid_t)-1;
}

/*******************************************************************
 Convert a name to a gid_t if possible. Return -1 if not a group. 
********************************************************************/

gid_t nametogid(const char *name)
{
	struct group *grp;
	char *p;
	gid_t g;

	g = (gid_t)strtol(name, &p, 0);
	if ((p != name) && (*p == '\0'))
		return g;

	grp = getgrnam(name);
	if (grp)
		return(grp->gr_gid);
	return (gid_t)-1;
}

/*******************************************************************
 Something really nasty happened - panic !
********************************************************************/

void smb_panic_s3(const char *why)
{
	char *cmd;
	int result;

	DEBUG(0,("PANIC (pid %llu): %s\n",
		    (unsigned long long)getpid(), why));
	log_stack_trace();

#if defined(HAVE_PRCTL) && defined(PR_SET_PTRACER)
	/*
	 * Make sure all children can attach a debugger.
	 */
	prctl(PR_SET_PTRACER, getpid(), 0, 0, 0);
#endif

	cmd = lp_panic_action(talloc_tos());
	if (cmd && *cmd) {
		DEBUG(0, ("smb_panic(): calling panic action [%s]\n", cmd));
		result = system(cmd);

		if (result == -1)
			DEBUG(0, ("smb_panic(): fork failed in panic action: %s\n",
					  strerror(errno)));
		else
			DEBUG(0, ("smb_panic(): action returned status %d\n",
					  WEXITSTATUS(result)));
	}

	dump_core();
}

/*******************************************************************
 Print a backtrace of the stack to the debug log. This function
 DELIBERATELY LEAKS MEMORY. The expectation is that you should
 exit shortly after calling it.
********************************************************************/

#ifdef HAVE_LIBUNWIND_H
#include <libunwind.h>
#endif

#ifdef HAVE_EXECINFO_H
#include <execinfo.h>
#endif

#ifdef HAVE_LIBEXC_H
#include <libexc.h>
#endif

void log_stack_trace(void)
{
#ifdef HAVE_LIBUNWIND
	/* Try to use libunwind before any other technique since on ia64
	 * libunwind correctly walks the stack in more circumstances than
	 * backtrace.
	 */ 
	unw_cursor_t cursor;
	unw_context_t uc;
	unsigned i = 0;

	char procname[256];
	unw_word_t ip, sp, off;

	procname[sizeof(procname) - 1] = '\0';

	if (unw_getcontext(&uc) != 0) {
		goto libunwind_failed;
	}

	if (unw_init_local(&cursor, &uc) != 0) {
		goto libunwind_failed;
	}

	DEBUG(0, ("BACKTRACE:\n"));

	do {
	    ip = sp = 0;
	    unw_get_reg(&cursor, UNW_REG_IP, &ip);
	    unw_get_reg(&cursor, UNW_REG_SP, &sp);

	    switch (unw_get_proc_name(&cursor,
			procname, sizeof(procname) - 1, &off) ) {
	    case 0:
		    /* Name found. */
	    case -UNW_ENOMEM:
		    /* Name truncated. */
		    DEBUGADD(0, (" #%u %s + %#llx [ip=%#llx] [sp=%#llx]\n",
			    i, procname, (long long)off,
			    (long long)ip, (long long) sp));
		    break;
	    default:
	    /* case -UNW_ENOINFO: */
	    /* case -UNW_EUNSPEC: */
		    /* No symbol name found. */
		    DEBUGADD(0, (" #%u %s [ip=%#llx] [sp=%#llx]\n",
			    i, "<unknown symbol>",
			    (long long)ip, (long long) sp));
	    }
	    ++i;
	} while (unw_step(&cursor) > 0);

	return;

libunwind_failed:
	DEBUG(0, ("unable to produce a stack trace with libunwind\n"));

#elif HAVE_BACKTRACE_SYMBOLS
	void *backtrace_stack[BACKTRACE_STACK_SIZE];
	size_t backtrace_size;
	char **backtrace_strings;

	/* get the backtrace (stack frames) */
	backtrace_size = backtrace(backtrace_stack,BACKTRACE_STACK_SIZE);
	backtrace_strings = backtrace_symbols(backtrace_stack, backtrace_size);

	DEBUG(0, ("BACKTRACE: %lu stack frames:\n", 
		  (unsigned long)backtrace_size));

	if (backtrace_strings) {
		int i;

		for (i = 0; i < backtrace_size; i++)
			DEBUGADD(0, (" #%u %s\n", i, backtrace_strings[i]));

		/* Leak the backtrace_strings, rather than risk what free() might do */
	}

#elif HAVE_LIBEXC

	/* The IRIX libexc library provides an API for unwinding the stack. See
	 * libexc(3) for details. Apparantly trace_back_stack leaks memory, but
	 * since we are about to abort anyway, it hardly matters.
	 */

#define NAMESIZE 32 /* Arbitrary */

	__uint64_t	addrs[BACKTRACE_STACK_SIZE];
	char *      	names[BACKTRACE_STACK_SIZE];
	char		namebuf[BACKTRACE_STACK_SIZE * NAMESIZE];

	int		i;
	int		levels;

	ZERO_ARRAY(addrs);
	ZERO_ARRAY(names);
	ZERO_ARRAY(namebuf);

	/* We need to be root so we can open our /proc entry to walk
	 * our stack. It also helps when we want to dump core.
	 */
	become_root();

	for (i = 0; i < BACKTRACE_STACK_SIZE; i++) {
		names[i] = namebuf + (i * NAMESIZE);
	}

	levels = trace_back_stack(0, addrs, names,
			BACKTRACE_STACK_SIZE, NAMESIZE - 1);

	DEBUG(0, ("BACKTRACE: %d stack frames:\n", levels));
	for (i = 0; i < levels; i++) {
		DEBUGADD(0, (" #%d 0x%llx %s\n", i, addrs[i], names[i]));
	}
#undef NAMESIZE

#else
	DEBUG(0, ("unable to produce a stack trace on this platform\n"));
#endif
}

/*******************************************************************
  A readdir wrapper which just returns the file name.
 ********************************************************************/

const char *readdirname(DIR *p)
{
	struct dirent *ptr;
	char *dname;

	if (!p)
		return(NULL);

	ptr = (struct dirent *)readdir(p);
	if (!ptr)
		return(NULL);

	dname = ptr->d_name;

#ifdef NEXT2
	if (telldir(p) < 0)
		return(NULL);
#endif

#ifdef HAVE_BROKEN_READDIR_NAME
	/* using /usr/ucb/cc is BAD */
	dname = dname - 2;
#endif

	return talloc_strdup(talloc_tos(), dname);
}

/*******************************************************************
 Utility function used to decide if the last component 
 of a path matches a (possibly wildcarded) entry in a namelist.
********************************************************************/

bool is_in_path(const char *name, name_compare_entry *namelist, bool case_sensitive)
{
	const char *last_component;

	/* if we have no list it's obviously not in the path */
	if((namelist == NULL ) || ((namelist != NULL) && (namelist[0].name == NULL))) {
		return False;
	}

	DEBUG(8, ("is_in_path: %s\n", name));

	/* Get the last component of the unix name. */
	last_component = strrchr_m(name, '/');
	if (!last_component) {
		last_component = name;
	} else {
		last_component++; /* Go past '/' */
	}

	for(; namelist->name != NULL; namelist++) {
		if(namelist->is_wild) {
			if (mask_match(last_component, namelist->name, case_sensitive)) {
				DEBUG(8,("is_in_path: mask match succeeded\n"));
				return True;
			}
		} else {
			if((case_sensitive && (strcmp(last_component, namelist->name) == 0))||
						(!case_sensitive && (strcasecmp_m(last_component, namelist->name) == 0))) {
				DEBUG(8,("is_in_path: match succeeded\n"));
				return True;
			}
		}
	}
	DEBUG(8,("is_in_path: match not found\n"));
	return False;
}

/*******************************************************************
 Strip a '/' separated list into an array of 
 name_compare_enties structures suitable for 
 passing to is_in_path(). We do this for
 speed so we can pre-parse all the names in the list 
 and don't do it for each call to is_in_path().
 We also check if the entry contains a wildcard to
 remove a potentially expensive call to mask_match
 if possible.
********************************************************************/

void set_namearray(name_compare_entry **ppname_array, const char *namelist_in)
{
	char *name_end;
	char *namelist;
	char *namelist_end;
	char *nameptr;
	int num_entries = 0;
	int i;

	(*ppname_array) = NULL;

	if((namelist_in == NULL ) || ((namelist_in != NULL) && (*namelist_in == '\0'))) 
		return;

	namelist = talloc_strdup(talloc_tos(), namelist_in);
	if (namelist == NULL) {
		DEBUG(0,("set_namearray: talloc fail\n"));
		return;
	}
	nameptr = namelist;

	namelist_end = &namelist[strlen(namelist)];

	/* We need to make two passes over the string. The
		first to count the number of elements, the second
		to split it.
	*/

	while(nameptr <= namelist_end) {
		if ( *nameptr == '/' ) {
			/* cope with multiple (useless) /s) */
			nameptr++;
			continue;
		}
		/* anything left? */
		if ( *nameptr == '\0' )
			break;

		/* find the next '/' or consume remaining */
		name_end = strchr_m(nameptr, '/');
		if (name_end == NULL) {
			/* Point nameptr at the terminating '\0' */
			nameptr += strlen(nameptr);
		} else {
			/* next segment please */
			nameptr = name_end + 1;
		}
		num_entries++;
	}

	if(num_entries == 0) {
		talloc_free(namelist);
		return;
	}

	if(( (*ppname_array) = SMB_MALLOC_ARRAY(name_compare_entry, num_entries + 1)) == NULL) {
		DEBUG(0,("set_namearray: malloc fail\n"));
		talloc_free(namelist);
		return;
	}

	/* Now copy out the names */
	nameptr = namelist;
	i = 0;
	while(nameptr <= namelist_end) {
		if ( *nameptr == '/' ) {
			/* cope with multiple (useless) /s) */
			nameptr++;
			continue;
		}
		/* anything left? */
		if ( *nameptr == '\0' )
			break;

		/* find the next '/' or consume remaining */
		name_end = strchr_m(nameptr, '/');
		if (name_end != NULL) {
			*name_end = '\0';
		}

		(*ppname_array)[i].is_wild = ms_has_wild(nameptr);
		if(((*ppname_array)[i].name = SMB_STRDUP(nameptr)) == NULL) {
			DEBUG(0,("set_namearray: malloc fail (1)\n"));
			talloc_free(namelist);
			return;
		}

		if (name_end == NULL) {
			/* Point nameptr at the terminating '\0' */
			nameptr += strlen(nameptr);
		} else {
			/* next segment please */
			nameptr = name_end + 1;
		}
		i++;
	}

	(*ppname_array)[i].name = NULL;

	talloc_free(namelist);
	return;
}

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_LOCKING

/****************************************************************************
 Simple routine to query existing file locks. Cruft in NFS and 64->32 bit mapping
 is dealt with in posix.c
 Returns True if we have information regarding this lock region (and returns
 F_UNLCK in *ptype if the region is unlocked). False if the call failed.
****************************************************************************/

bool fcntl_getlock(int fd, off_t *poffset, off_t *pcount, int *ptype, pid_t *ppid)
{
	struct flock lock;
	int ret;

	DEBUG(8,("fcntl_getlock fd=%d offset=%.0f count=%.0f type=%d\n",
		    fd,(double)*poffset,(double)*pcount,*ptype));

	lock.l_type = *ptype;
	lock.l_whence = SEEK_SET;
	lock.l_start = *poffset;
	lock.l_len = *pcount;
	lock.l_pid = 0;

	ret = sys_fcntl_ptr(fd,F_GETLK,&lock);

	if (ret == -1) {
		int sav = errno;
		DEBUG(3,("fcntl_getlock: lock request failed at offset %.0f count %.0f type %d (%s)\n",
			(double)*poffset,(double)*pcount,*ptype,strerror(errno)));
		errno = sav;
		return False;
	}

	*ptype = lock.l_type;
	*poffset = lock.l_start;
	*pcount = lock.l_len;
	*ppid = lock.l_pid;

	DEBUG(3,("fcntl_getlock: fd %d is returned info %d pid %u\n",
			fd, (int)lock.l_type, (unsigned int)lock.l_pid));
	return True;
}

#undef DBGC_CLASS
#define DBGC_CLASS DBGC_ALL

/*******************************************************************
 Is the name specified one of my netbios names.
 Returns true if it is equal, false otherwise.
********************************************************************/

bool is_myname(const char *s)
{
	int n;
	bool ret = False;

	for (n=0; my_netbios_names(n); n++) {
		const char *nbt_name = my_netbios_names(n);

		if (strncasecmp_m(nbt_name, s, MAX_NETBIOSNAME_LEN-1) == 0) {
			ret=True;
			break;
		}
	}
	DEBUG(8, ("is_myname(\"%s\") returns %d\n", s, ret));
	return(ret);
}

/*******************************************************************
 we distinguish between 2K and XP by the "Native Lan Manager" string
   WinXP => "Windows 2002 5.1"
   WinXP 64bit => "Windows XP 5.2"
   Win2k => "Windows 2000 5.0"
   NT4   => "Windows NT 4.0"
   Win9x => "Windows 4.0"
 Windows 2003 doesn't set the native lan manager string but
 they do set the domain to "Windows 2003 5.2" (probably a bug).
********************************************************************/

void ra_lanman_string( const char *native_lanman )
{
	if ( strcmp( native_lanman, "Windows 2002 5.1" ) == 0 )
		set_remote_arch( RA_WINXP );
	else if ( strcmp( native_lanman, "Windows XP 5.2" ) == 0 )
		set_remote_arch( RA_WINXP64 );
	else if ( strcmp( native_lanman, "Windows Server 2003 5.2" ) == 0 )
		set_remote_arch( RA_WIN2K3 );
}

static const char *remote_arch_str;

const char *get_remote_arch_str(void)
{
	if (!remote_arch_str) {
		return "UNKNOWN";
	}
	return remote_arch_str;
}

/*******************************************************************
 Set the horrid remote_arch string based on an enum.
********************************************************************/

void set_remote_arch(enum remote_arch_types type)
{
	ra_type = type;
	switch( type ) {
	case RA_WFWG:
		remote_arch_str = "WfWg";
		break;
	case RA_OS2:
		remote_arch_str = "OS2";
		break;
	case RA_WIN95:
		remote_arch_str = "Win95";
		break;
	case RA_WINNT:
		remote_arch_str = "WinNT";
		break;
	case RA_WIN2K:
		remote_arch_str = "Win2K";
		break;
	case RA_WINXP:
		remote_arch_str = "WinXP";
		break;
	case RA_WINXP64:
		remote_arch_str = "WinXP64";
		break;
	case RA_WIN2K3:
		remote_arch_str = "Win2K3";
		break;
	case RA_VISTA:
		remote_arch_str = "Vista";
		break;
	case RA_SAMBA:
		remote_arch_str = "Samba";
		break;
	case RA_CIFSFS:
		remote_arch_str = "CIFSFS";
		break;
	case RA_OSX:
		remote_arch_str = "OSX";
		break;
	default:
		ra_type = RA_UNKNOWN;
		remote_arch_str = "UNKNOWN";
		break;
	}

	DEBUG(10,("set_remote_arch: Client arch is \'%s\'\n",
				remote_arch_str));
}

/*******************************************************************
 Get the remote_arch type.
********************************************************************/

enum remote_arch_types get_remote_arch(void)
{
	return ra_type;
}

const char *tab_depth(int level, int depth)
{
	if( CHECK_DEBUGLVL(level) ) {
		dbgtext("%*s", depth*4, "");
	}
	return "";
}

/*****************************************************************************
 Provide a checksum on a string

 Input:  s - the null-terminated character string for which the checksum
             will be calculated.

  Output: The checksum value calculated for s.
*****************************************************************************/

int str_checksum(const char *s)
{
	TDB_DATA key;
	if (s == NULL)
		return 0;

	key = (TDB_DATA) { .dptr = discard_const_p(uint8_t, s),
			   .dsize = strlen(s) };

	return tdb_jenkins_hash(&key);
}

/*****************************************************************
 Zero a memory area then free it. Used to catch bugs faster.
*****************************************************************/  

void zero_free(void *p, size_t size)
{
	memset(p, 0, size);
	SAFE_FREE(p);
}

/*****************************************************************
 Set our open file limit to a requested max and return the limit.
*****************************************************************/  

int set_maxfiles(int requested_max)
{
#if (defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE))
	struct rlimit rlp;
	int saved_current_limit;

	if(getrlimit(RLIMIT_NOFILE, &rlp)) {
		DEBUG(0,("set_maxfiles: getrlimit (1) for RLIMIT_NOFILE failed with error %s\n",
			strerror(errno) ));
		/* just guess... */
		return requested_max;
	}

	/* 
	 * Set the fd limit to be real_max_open_files + MAX_OPEN_FUDGEFACTOR to
	 * account for the extra fd we need 
	 * as well as the log files and standard
	 * handles etc. Save the limit we want to set in case
	 * we are running on an OS that doesn't support this limit (AIX)
	 * which always returns RLIM_INFINITY for rlp.rlim_max.
	 */

	/* Try raising the hard (max) limit to the requested amount. */

#if defined(RLIM_INFINITY)
	if (rlp.rlim_max != RLIM_INFINITY) {
		int orig_max = rlp.rlim_max;

		if ( rlp.rlim_max < requested_max )
			rlp.rlim_max = requested_max;

		/* This failing is not an error - many systems (Linux) don't
			support our default request of 10,000 open files. JRA. */

		if(setrlimit(RLIMIT_NOFILE, &rlp)) {
			DEBUG(3,("set_maxfiles: setrlimit for RLIMIT_NOFILE for %d max files failed with error %s\n", 
				(int)rlp.rlim_max, strerror(errno) ));

			/* Set failed - restore original value from get. */
			rlp.rlim_max = orig_max;
		}
	}
#endif

	/* Now try setting the soft (current) limit. */

	saved_current_limit = rlp.rlim_cur = MIN(requested_max,rlp.rlim_max);

	if(setrlimit(RLIMIT_NOFILE, &rlp)) {
		DEBUG(0,("set_maxfiles: setrlimit for RLIMIT_NOFILE for %d files failed with error %s\n", 
			(int)rlp.rlim_cur, strerror(errno) ));
		/* just guess... */
		return saved_current_limit;
	}

	if(getrlimit(RLIMIT_NOFILE, &rlp)) {
		DEBUG(0,("set_maxfiles: getrlimit (2) for RLIMIT_NOFILE failed with error %s\n",
			strerror(errno) ));
		/* just guess... */
		return saved_current_limit;
    }

#if defined(RLIM_INFINITY)
	if(rlp.rlim_cur == RLIM_INFINITY)
		return saved_current_limit;
#endif

	if((int)rlp.rlim_cur > saved_current_limit)
		return saved_current_limit;

	return rlp.rlim_cur;
#else /* !defined(HAVE_GETRLIMIT) || !defined(RLIMIT_NOFILE) */
	/*
	 * No way to know - just guess...
	 */
	return requested_max;
#endif
}

/*****************************************************************
 malloc that aborts with smb_panic on fail or zero size.
 *****************************************************************/  

void *smb_xmalloc_array(size_t size, unsigned int count)
{
	void *p;
	if (size == 0) {
		smb_panic("smb_xmalloc_array: called with zero size");
	}
        if (count >= MAX_ALLOC_SIZE/size) {
                smb_panic("smb_xmalloc_array: alloc size too large");
        }
	if ((p = SMB_MALLOC(size*count)) == NULL) {
		DEBUG(0, ("smb_xmalloc_array failed to allocate %lu * %lu bytes\n",
			(unsigned long)size, (unsigned long)count));
		smb_panic("smb_xmalloc_array: malloc failed");
	}
	return p;
}

/*
  vasprintf that aborts on malloc fail
*/

 int smb_xvasprintf(char **ptr, const char *format, va_list ap)
{
	int n;
	va_list ap2;

	va_copy(ap2, ap);

	n = vasprintf(ptr, format, ap2);
	va_end(ap2);
	if (n == -1 || ! *ptr) {
		smb_panic("smb_xvasprintf: out of memory");
	}
	return n;
}

/*****************************************************************
 Get local hostname and cache result.
*****************************************************************/

char *myhostname(void)
{
	static char *ret;
	if (ret == NULL) {
		ret = get_myname(NULL);
	}
	return ret;
}

/*****************************************************************
 Get local hostname and cache result.
*****************************************************************/

char *myhostname_upper(void)
{
	static char *ret;
	if (ret == NULL) {
		char *name = get_myname(NULL);
		if (name == NULL) {
			return NULL;
		}
		ret = strupper_talloc(NULL, name);
		talloc_free(name);
	}
	return ret;
}

/**
 * @brief Returns an absolute path to a file concatenating the provided
 * @a rootpath and @a basename
 *
 * @param name Filename, relative to @a rootpath
 *
 * @retval Pointer to a string containing the full path.
 **/

static char *xx_path(const char *name, const char *rootpath)
{
	char *fname = NULL;

	fname = talloc_strdup(talloc_tos(), rootpath);
	if (!fname) {
		return NULL;
	}
	trim_string(fname,"","/");

	if (!directory_exist(fname)) {
		if (mkdir(fname,0755) == -1) {
			/* Did someone else win the race ? */
			if (errno != EEXIST) {
				DEBUG(1, ("Unable to create directory %s for file %s. "
					"Error was %s\n", fname, name, strerror(errno)));
				return NULL;
			}
		}
	}

	return talloc_asprintf_append(fname, "/%s", name);
}

/**
 * @brief Returns an absolute path to a file in the Samba lock directory.
 *
 * @param name File to find, relative to LOCKDIR.
 *
 * @retval Pointer to a talloc'ed string containing the full path.
 **/

char *lock_path(const char *name)
{
	return xx_path(name, lp_lock_directory());
}

/**
 * @brief Returns an absolute path to a file in the Samba state directory.
 *
 * @param name File to find, relative to STATEDIR.
 *
 * @retval Pointer to a talloc'ed string containing the full path.
 **/

char *state_path(const char *name)
{
	return xx_path(name, lp_state_directory());
}

/**
 * @brief Returns an absolute path to a file in the Samba cache directory.
 *
 * @param name File to find, relative to CACHEDIR.
 *
 * @retval Pointer to a talloc'ed string containing the full path.
 **/

char *cache_path(const char *name)
{
	return xx_path(name, lp_cache_directory());
}

/*******************************************************************
 Given a filename - get its directory name
********************************************************************/

bool parent_dirname(TALLOC_CTX *mem_ctx, const char *dir, char **parent,
		    const char **name)
{
	char *p;
	ptrdiff_t len;

	p = strrchr_m(dir, '/'); /* Find final '/', if any */

	if (p == NULL) {
		if (!(*parent = talloc_strdup(mem_ctx, "."))) {
			return False;
		}
		if (name) {
			*name = dir;
		}
		return True;
	}

	len = p-dir;

	if (!(*parent = (char *)talloc_memdup(mem_ctx, dir, len+1))) {
		return False;
	}
	(*parent)[len] = '\0';

	if (name) {
		*name = p+1;
	}
	return True;
}

/*******************************************************************
 Determine if a pattern contains any Microsoft wildcard characters.
*******************************************************************/

bool ms_has_wild(const char *s)
{
	char c;

	while ((c = *s++)) {
		switch (c) {
		case '*':
		case '?':
		case '<':
		case '>':
		case '"':
			return True;
		}
	}
	return False;
}

bool ms_has_wild_w(const smb_ucs2_t *s)
{
	smb_ucs2_t c;
	if (!s) return False;
	while ((c = *s++)) {
		switch (c) {
		case UCS2_CHAR('*'):
		case UCS2_CHAR('?'):
		case UCS2_CHAR('<'):
		case UCS2_CHAR('>'):
		case UCS2_CHAR('"'):
			return True;
		}
	}
	return False;
}

/*******************************************************************
 A wrapper that handles case sensitivity and the special handling
 of the ".." name.
*******************************************************************/

bool mask_match(const char *string, const char *pattern, bool is_case_sensitive)
{
	if (ISDOTDOT(string))
		string = ".";
	if (ISDOT(pattern))
		return False;

	return ms_fnmatch(pattern, string, Protocol <= PROTOCOL_LANMAN2, is_case_sensitive) == 0;
}

/*******************************************************************
 A wrapper that handles case sensitivity and the special handling
 of the ".." name. Varient that is only called by old search code which requires
 pattern translation.
*******************************************************************/

bool mask_match_search(const char *string, const char *pattern, bool is_case_sensitive)
{
	if (ISDOTDOT(string))
		string = ".";
	if (ISDOT(pattern))
		return False;

	return ms_fnmatch(pattern, string, True, is_case_sensitive) == 0;
}

/*******************************************************************
 A wrapper that handles a list of patters and calls mask_match()
 on each.  Returns True if any of the patterns match.
*******************************************************************/

bool mask_match_list(const char *string, char **list, int listLen, bool is_case_sensitive)
{
       while (listLen-- > 0) {
               if (mask_match(string, *list++, is_case_sensitive))
                       return True;
       }
       return False;
}

/*********************************************************
 Recursive routine that is called by unix_wild_match.
*********************************************************/

static bool unix_do_match(const char *regexp, const char *str)
{
	const char *p;

	for( p = regexp; *p && *str; ) {

		switch(*p) {
			case '?':
				str++;
				p++;
				break;

			case '*':

				/*
				 * Look for a character matching 
				 * the one after the '*'.
				 */
				p++;
				if(!*p)
					return true; /* Automatic match */
				while(*str) {

					while(*str && (*p != *str))
						str++;

					/*
					 * Patch from weidel@multichart.de. In the case of the regexp
					 * '*XX*' we want to ensure there are at least 2 'X' characters
					 * in the string after the '*' for a match to be made.
					 */

					{
						int matchcount=0;

						/*
						 * Eat all the characters that match, but count how many there were.
						 */

						while(*str && (*p == *str)) {
							str++;
							matchcount++;
						}

						/*
						 * Now check that if the regexp had n identical characters that
						 * matchcount had at least that many matches.
						 */

						while ( *(p+1) && (*(p+1) == *p)) {
							p++;
							matchcount--;
						}

						if ( matchcount <= 0 )
							return false;
					}

					str--; /* We've eaten the match char after the '*' */

					if(unix_do_match(p, str))
						return true;

					if(!*str)
						return false;
					else
						str++;
				}
				return false;

			default:
				if(*str != *p)
					return false;
				str++;
				p++;
				break;
		}
	}

	if(!*p && !*str)
		return true;

	if (!*p && str[0] == '.' && str[1] == 0)
		return true;

	if (!*str && *p == '?') {
		while (*p == '?')
			p++;
		return(!*p);
	}

	if(!*str && (*p == '*' && p[1] == '\0'))
		return true;

	return false;
}

/*******************************************************************
 Simple case insensitive interface to a UNIX wildcard matcher.
 Returns True if match, False if not.
*******************************************************************/

bool unix_wild_match(const char *pattern, const char *string)
{
	TALLOC_CTX *ctx = talloc_stackframe();
	char *p2;
	char *s2;
	char *p;
	bool ret = false;

	p2 = talloc_strdup(ctx,pattern);
	s2 = talloc_strdup(ctx,string);
	if (!p2 || !s2) {
		TALLOC_FREE(ctx);
		return false;
	}
	if (!strlower_m(p2)) {
		TALLOC_FREE(ctx);
		return false;
	}
	if (!strlower_m(s2)) {
		TALLOC_FREE(ctx);
		return false;
	}

	/* Remove any *? and ** from the pattern as they are meaningless */
	for(p = p2; *p; p++) {
		while( *p == '*' && (p[1] == '?' ||p[1] == '*')) {
			memmove(&p[1], &p[2], strlen(&p[2])+1);
		}
	}

	if (strequal(p2,"*")) {
		TALLOC_FREE(ctx);
		return true;
	}

	ret = unix_do_match(p2, s2);
	TALLOC_FREE(ctx);
	return ret;
}

/**********************************************************************
  Converts a name to a fully qualified domain name.
  Returns true if lookup succeeded, false if not (then fqdn is set to name)
  Uses getaddrinfo() with AI_CANONNAME flag to obtain the official
  canonical name of the host. getaddrinfo() may use a variety of sources
  including /etc/hosts to obtain the domainname. It expects aliases in
  /etc/hosts to NOT be the FQDN. The FQDN should come first.
************************************************************************/

bool name_to_fqdn(fstring fqdn, const char *name)
{
	char *full = NULL;
	struct addrinfo hints;
	struct addrinfo *result;
	int s;

	/* Configure hints to obtain canonical name */

	memset(&hints, 0, sizeof(struct addrinfo));
	hints.ai_family = AF_UNSPEC;    /* Allow IPv4 or IPv6 */
	hints.ai_socktype = SOCK_DGRAM; /* Datagram socket */
	hints.ai_flags = AI_CANONNAME;  /* Get host's FQDN */
	hints.ai_protocol = 0;          /* Any protocol */

	s = getaddrinfo(name, NULL, &hints, &result);
	if (s != 0) {
		DEBUG(1, ("getaddrinfo: %s\n", gai_strerror(s)));
		DEBUG(10,("name_to_fqdn: lookup for %s failed.\n", name));
		fstrcpy(fqdn, name);
		return false;
	}
	full = result->ai_canonname;

	/* Find out if the FQDN is returned as an alias
	 * to cope with /etc/hosts files where the first
	 * name is not the FQDN but the short name.
	 * getaddrinfo provides no easy way of handling aliases
	 * in /etc/hosts. Users should make sure the FQDN
	 * comes first in /etc/hosts. */
	if (full && (! strchr_m(full, '.'))) {
		DEBUG(1, ("WARNING: your /etc/hosts file may be broken!\n"));
		DEBUGADD(1, ("    Full qualified domain names (FQDNs) should not be specified\n"));
		DEBUGADD(1, ("    as an alias in /etc/hosts. FQDN should be the first name\n"));
		DEBUGADD(1, ("    prior to any aliases.\n"));
	}
	if (full && (strcasecmp_m(full, "localhost.localdomain") == 0)) {
		DEBUG(1, ("WARNING: your /etc/hosts file may be broken!\n"));
		DEBUGADD(1, ("    Specifying the machine hostname for address 127.0.0.1 may lead\n"));
		DEBUGADD(1, ("    to Kerberos authentication problems as localhost.localdomain\n"));
		DEBUGADD(1, ("    may end up being used instead of the real machine FQDN.\n"));
	}

	DEBUG(10,("name_to_fqdn: lookup for %s -> %s.\n", name, full));
	fstrcpy(fqdn, full);
	freeaddrinfo(result);           /* No longer needed */
	return true;
}

/**********************************************************************
 Append a DATA_BLOB to a talloc'ed object
***********************************************************************/

void *talloc_append_blob(TALLOC_CTX *mem_ctx, void *buf, DATA_BLOB blob)
{
	size_t old_size = 0;
	char *result;

	if (blob.length == 0) {
		return buf;
	}

	if (buf != NULL) {
		old_size = talloc_get_size(buf);
	}

	result = (char *)TALLOC_REALLOC(mem_ctx, buf, old_size + blob.length);
	if (result == NULL) {
		return NULL;
	}

	memcpy(result + old_size, blob.data, blob.length);
	return result;
}

uint32_t map_share_mode_to_deny_mode(uint32_t share_access, uint32_t private_options)
{
	switch (share_access & ~FILE_SHARE_DELETE) {
		case FILE_SHARE_NONE:
			return DENY_ALL;
		case FILE_SHARE_READ:
			return DENY_WRITE;
		case FILE_SHARE_WRITE:
			return DENY_READ;
		case FILE_SHARE_READ|FILE_SHARE_WRITE:
			return DENY_NONE;
	}
	if (private_options & NTCREATEX_OPTIONS_PRIVATE_DENY_DOS) {
		return DENY_DOS;
	} else if (private_options & NTCREATEX_OPTIONS_PRIVATE_DENY_FCB) {
		return DENY_FCB;
	}

	return (uint32_t)-1;
}

struct server_id interpret_pid(const char *pid_string)
{
	return server_id_from_string(get_my_vnn(), pid_string);
}

/****************************************************************
 Check if an offset into a buffer is safe.
 If this returns True it's safe to indirect into the byte at
 pointer ptr+off.
****************************************************************/

bool is_offset_safe(const char *buf_base, size_t buf_len, char *ptr, size_t off)
{
	const char *end_base = buf_base + buf_len;
	char *end_ptr = ptr + off;

	if (!buf_base || !ptr) {
		return False;
	}

	if (end_base < buf_base || end_ptr < ptr) {
		return False; /* wrap. */
	}

	if (end_ptr < end_base) {
		return True;
	}
	return False;
}

/****************************************************************
 Return a safe pointer into a buffer, or NULL.
****************************************************************/

char *get_safe_ptr(const char *buf_base, size_t buf_len, char *ptr, size_t off)
{
	return is_offset_safe(buf_base, buf_len, ptr, off) ?
			ptr + off : NULL;
}

/****************************************************************
 Return a safe pointer into a string within a buffer, or NULL.
****************************************************************/

char *get_safe_str_ptr(const char *buf_base, size_t buf_len, char *ptr, size_t off)
{
	if (!is_offset_safe(buf_base, buf_len, ptr, off)) {
		return NULL;
	}
	/* Check if a valid string exists at this offset. */
	if (skip_string(buf_base,buf_len, ptr + off) == NULL) {
		return NULL;
	}
	return ptr + off;
}

/****************************************************************
 Return an SVAL at a pointer, or failval if beyond the end.
****************************************************************/

int get_safe_SVAL(const char *buf_base, size_t buf_len, char *ptr, size_t off, int failval)
{
	/*
	 * Note we use off+1 here, not off+2 as SVAL accesses ptr[0] and ptr[1],
 	 * NOT ptr[2].
 	 */
	if (!is_offset_safe(buf_base, buf_len, ptr, off+1)) {
		return failval;
	}
	return SVAL(ptr,off);
}

/****************************************************************
 Return an IVAL at a pointer, or failval if beyond the end.
****************************************************************/

int get_safe_IVAL(const char *buf_base, size_t buf_len, char *ptr, size_t off, int failval)
{
	/*
	 * Note we use off+3 here, not off+4 as IVAL accesses 
	 * ptr[0] ptr[1] ptr[2] ptr[3] NOT ptr[4].
 	 */
	if (!is_offset_safe(buf_base, buf_len, ptr, off+3)) {
		return failval;
	}
	return IVAL(ptr,off);
}

/****************************************************************
 Split DOM\user into DOM and user. Do not mix with winbind variants of that
 call (they take care of winbind separator and other winbind specific settings).
****************************************************************/

void split_domain_user(TALLOC_CTX *mem_ctx,
		       const char *full_name,
		       char **domain,
		       char **user)
{
	const char *p = NULL;

	p = strchr_m(full_name, '\\');

	if (p != NULL) {
		*domain = talloc_strndup(mem_ctx, full_name,
					 PTR_DIFF(p, full_name));
		*user = talloc_strdup(mem_ctx, p+1);
	} else {
		*domain = talloc_strdup(mem_ctx, "");
		*user = talloc_strdup(mem_ctx, full_name);
	}
}

/****************************************************************
 strip off leading '\\' from a hostname
****************************************************************/

const char *strip_hostname(const char *s)
{
	if (!s) {
		return NULL;
	}

	if (strlen_m(s) < 3) {
		return s;
	}

	if (s[0] == '\\') s++;
	if (s[0] == '\\') s++;

	return s;
}

bool any_nt_status_not_ok(NTSTATUS err1, NTSTATUS err2, NTSTATUS *result)
{
	if (!NT_STATUS_IS_OK(err1)) {
		*result = err1;
		return true;
	}
	if (!NT_STATUS_IS_OK(err2)) {
		*result = err2;
		return true;
	}
	return false;
}

int timeval_to_msec(struct timeval t)
{
	return t.tv_sec * 1000 + (t.tv_usec+999) / 1000;
}

/*******************************************************************
 Check a given DOS pathname is valid for a share.
********************************************************************/

char *valid_share_pathname(TALLOC_CTX *ctx, const char *dos_pathname)
{
	char *ptr = NULL;

	if (!dos_pathname) {
		return NULL;
	}

	ptr = talloc_strdup(ctx, dos_pathname);
	if (!ptr) {
		return NULL;
	}
	/* Convert any '\' paths to '/' */
	unix_format(ptr);
	ptr = unix_clean_name(ctx, ptr);
	if (!ptr) {
		return NULL;
	}

	/* NT is braindead - it wants a C: prefix to a pathname ! So strip it. */
	if (strlen(ptr) > 2 && ptr[1] == ':' && ptr[0] != '/')
		ptr += 2;

	/* Only absolute paths allowed. */
	if (*ptr != '/')
		return NULL;

	return ptr;
}

/*******************************************************************
 Return True if the filename is one of the special executable types.
********************************************************************/

bool is_executable(const char *fname)
{
	if ((fname = strrchr_m(fname,'.'))) {
		if (strequal(fname,".com") ||
		    strequal(fname,".dll") ||
		    strequal(fname,".exe") ||
		    strequal(fname,".sym")) {
			return True;
		}
	}
	return False;
}

/****************************************************************************
 Open a file with a share mode - old openX method - map into NTCreate.
****************************************************************************/

bool map_open_params_to_ntcreate(const char *smb_base_fname,
				 int deny_mode, int open_func,
				 uint32_t *paccess_mask,
				 uint32_t *pshare_mode,
				 uint32_t *pcreate_disposition,
				 uint32_t *pcreate_options,
				 uint32_t *pprivate_flags)
{
	uint32_t access_mask;
	uint32_t share_mode;
	uint32_t create_disposition;
	uint32_t create_options = FILE_NON_DIRECTORY_FILE;
	uint32_t private_flags = 0;

	DEBUG(10,("map_open_params_to_ntcreate: fname = %s, deny_mode = 0x%x, "
		  "open_func = 0x%x\n",
		  smb_base_fname, (unsigned int)deny_mode,
		  (unsigned int)open_func ));

	/* Create the NT compatible access_mask. */
	switch (GET_OPENX_MODE(deny_mode)) {
		case DOS_OPEN_EXEC: /* Implies read-only - used to be FILE_READ_DATA */
		case DOS_OPEN_RDONLY:
			access_mask = FILE_GENERIC_READ;
			break;
		case DOS_OPEN_WRONLY:
			access_mask = FILE_GENERIC_WRITE;
			break;
		case DOS_OPEN_RDWR:
		case DOS_OPEN_FCB:
			access_mask = FILE_GENERIC_READ|FILE_GENERIC_WRITE;
			break;
		default:
			DEBUG(10,("map_open_params_to_ntcreate: bad open mode = 0x%x\n",
				  (unsigned int)GET_OPENX_MODE(deny_mode)));
			return False;
	}

	/* Create the NT compatible create_disposition. */
	switch (open_func) {
		case OPENX_FILE_EXISTS_FAIL|OPENX_FILE_CREATE_IF_NOT_EXIST:
			create_disposition = FILE_CREATE;
			break;

		case OPENX_FILE_EXISTS_OPEN:
			create_disposition = FILE_OPEN;
			break;

		case OPENX_FILE_EXISTS_OPEN|OPENX_FILE_CREATE_IF_NOT_EXIST:
			create_disposition = FILE_OPEN_IF;
			break;

		case OPENX_FILE_EXISTS_TRUNCATE:
			create_disposition = FILE_OVERWRITE;
			break;

		case OPENX_FILE_EXISTS_TRUNCATE|OPENX_FILE_CREATE_IF_NOT_EXIST:
			create_disposition = FILE_OVERWRITE_IF;
			break;

		default:
			/* From samba4 - to be confirmed. */
			if (GET_OPENX_MODE(deny_mode) == DOS_OPEN_EXEC) {
				create_disposition = FILE_CREATE;
				break;
			}
			DEBUG(10,("map_open_params_to_ntcreate: bad "
				  "open_func 0x%x\n", (unsigned int)open_func));
			return False;
	}

	/* Create the NT compatible share modes. */
	switch (GET_DENY_MODE(deny_mode)) {
		case DENY_ALL:
			share_mode = FILE_SHARE_NONE;
			break;

		case DENY_WRITE:
			share_mode = FILE_SHARE_READ;
			break;

		case DENY_READ:
			share_mode = FILE_SHARE_WRITE;
			break;

		case DENY_NONE:
			share_mode = FILE_SHARE_READ|FILE_SHARE_WRITE;
			break;

		case DENY_DOS:
			private_flags |= NTCREATEX_OPTIONS_PRIVATE_DENY_DOS;
	                if (is_executable(smb_base_fname)) {
				share_mode = FILE_SHARE_READ|FILE_SHARE_WRITE;
			} else {
				if (GET_OPENX_MODE(deny_mode) == DOS_OPEN_RDONLY) {
					share_mode = FILE_SHARE_READ;
				} else {
					share_mode = FILE_SHARE_NONE;
				}
			}
			break;

		case DENY_FCB:
			private_flags |= NTCREATEX_OPTIONS_PRIVATE_DENY_FCB;
			share_mode = FILE_SHARE_NONE;
			break;

		default:
			DEBUG(10,("map_open_params_to_ntcreate: bad deny_mode 0x%x\n",
				(unsigned int)GET_DENY_MODE(deny_mode) ));
			return False;
	}

	DEBUG(10,("map_open_params_to_ntcreate: file %s, access_mask = 0x%x, "
		  "share_mode = 0x%x, create_disposition = 0x%x, "
		  "create_options = 0x%x private_flags = 0x%x\n",
		  smb_base_fname,
		  (unsigned int)access_mask,
		  (unsigned int)share_mode,
		  (unsigned int)create_disposition,
		  (unsigned int)create_options,
		  (unsigned int)private_flags));

	if (paccess_mask) {
		*paccess_mask = access_mask;
	}
	if (pshare_mode) {
		*pshare_mode = share_mode;
	}
	if (pcreate_disposition) {
		*pcreate_disposition = create_disposition;
	}
	if (pcreate_options) {
		*pcreate_options = create_options;
	}
	if (pprivate_flags) {
		*pprivate_flags = private_flags;
	}

	return True;

}

/*************************************************************************
 Return a talloced copy of a struct security_unix_token. NULL on fail.
*************************************************************************/

struct security_unix_token *copy_unix_token(TALLOC_CTX *ctx, const struct security_unix_token *tok)
{
	struct security_unix_token *cpy;

	cpy = talloc(ctx, struct security_unix_token);
	if (!cpy) {
		return NULL;
	}

	cpy->uid = tok->uid;
	cpy->gid = tok->gid;
	cpy->ngroups = tok->ngroups;
	if (tok->ngroups) {
		/* Make this a talloc child of cpy. */
		cpy->groups = (gid_t *)talloc_memdup(
			cpy, tok->groups, tok->ngroups * sizeof(gid_t));
		if (!cpy->groups) {
			TALLOC_FREE(cpy);
			return NULL;
		}
	} else {
		cpy->groups = NULL;
	}
	return cpy;
}

/****************************************************************************
 Check that a file matches a particular file type.
****************************************************************************/

bool dir_check_ftype(uint32_t mode, uint32_t dirtype)
{
	uint32_t mask;

	/* Check the "may have" search bits. */
	if (((mode & ~dirtype) &
			(FILE_ATTRIBUTE_HIDDEN |
			 FILE_ATTRIBUTE_SYSTEM |
			 FILE_ATTRIBUTE_DIRECTORY)) != 0) {
		return false;
	}

	/* Check the "must have" bits,
	   which are the may have bits shifted eight */
	/* If must have bit is set, the file/dir can
	   not be returned in search unless the matching
	   file attribute is set */
	mask = ((dirtype >> 8) & (FILE_ATTRIBUTE_DIRECTORY|
				    FILE_ATTRIBUTE_ARCHIVE|
				   FILE_ATTRIBUTE_READONLY|
				     FILE_ATTRIBUTE_HIDDEN|
				     FILE_ATTRIBUTE_SYSTEM)); /* & 0x37 */
	if(mask) {
		if((mask & (mode & (FILE_ATTRIBUTE_DIRECTORY|
				      FILE_ATTRIBUTE_ARCHIVE|
				     FILE_ATTRIBUTE_READONLY|
				       FILE_ATTRIBUTE_HIDDEN|
					FILE_ATTRIBUTE_SYSTEM))) == mask) {
			/* check if matching attribute present */
			return true;
		} else {
			return false;
		}
	}

	return true;
}