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samba-mirror/source3/lib/substitute.c
2009-11-21 20:54:10 +01:00

917 lines
22 KiB
C

/*
Unix SMB/CIFS implementation.
string substitution functions
Copyright (C) Andrew Tridgell 1992-2000
Copyright (C) Gerald Carter 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"
static char *alloc_sub_basic(const char *smb_name, const char *domain_name,
const char *str);
userdom_struct current_user_info;
fstring remote_proto="UNKNOWN";
/**
* Set the 'local' machine name
* @param local_name the name we are being called
* @param if this is the 'final' name for us, not be be changed again
*/
static char *local_machine;
void free_local_machine_name(void)
{
SAFE_FREE(local_machine);
}
bool set_local_machine_name(const char *local_name, bool perm)
{
static bool already_perm = false;
char *tmp_local_machine = NULL;
char addr[INET6_ADDRSTRLEN];
size_t len;
tmp_local_machine = SMB_STRDUP(local_name);
if (!tmp_local_machine) {
return false;
}
trim_char(tmp_local_machine,' ',' ');
/*
* Windows NT/2k uses "*SMBSERVER" and XP uses "*SMBSERV"
* arrggg!!!
*/
if (strequal(tmp_local_machine, "*SMBSERVER") ||
strequal(tmp_local_machine, "*SMBSERV") ) {
SAFE_FREE(local_machine);
local_machine = SMB_STRDUP(client_socket_addr(get_client_fd(),
addr, sizeof(addr)) );
SAFE_FREE(tmp_local_machine);
return local_machine ? true : false;
}
if (already_perm) {
return true;
}
SAFE_FREE(local_machine);
len = strlen(tmp_local_machine);
local_machine = SMB_CALLOC_ARRAY(char, len+1);
if (!local_machine) {
SAFE_FREE(tmp_local_machine);
return false;
}
/* alpha_strcpy includes the space for the terminating nul. */
alpha_strcpy(local_machine,tmp_local_machine,
SAFE_NETBIOS_CHARS,len+1);
strlower_m(local_machine);
SAFE_FREE(tmp_local_machine);
already_perm = perm;
return true;
}
const char *get_local_machine_name(void)
{
if (!local_machine || !*local_machine) {
return global_myname();
}
return local_machine;
}
/**
* Set the 'remote' machine name
* @param remote_name the name our client wants to be called by
* @param if this is the 'final' name for them, not be be changed again
*/
static char *remote_machine;
bool set_remote_machine_name(const char *remote_name, bool perm)
{
static bool already_perm = False;
char *tmp_remote_machine;
size_t len;
if (already_perm) {
return true;
}
tmp_remote_machine = SMB_STRDUP(remote_name);
if (!tmp_remote_machine) {
return false;
}
trim_char(tmp_remote_machine,' ',' ');
SAFE_FREE(remote_machine);
len = strlen(tmp_remote_machine);
remote_machine = SMB_CALLOC_ARRAY(char, len+1);
if (!remote_machine) {
SAFE_FREE(tmp_remote_machine);
return false;
}
/* alpha_strcpy includes the space for the terminating nul. */
alpha_strcpy(remote_machine,tmp_remote_machine,
SAFE_NETBIOS_CHARS,len+1);
strlower_m(remote_machine);
SAFE_FREE(tmp_remote_machine);
already_perm = perm;
return true;
}
const char *get_remote_machine_name(void)
{
return remote_machine ? remote_machine : "";
}
/*******************************************************************
Setup the string used by %U substitution.
********************************************************************/
static char *smb_user_name;
void sub_set_smb_name(const char *name)
{
char *tmp;
size_t len;
bool is_machine_account = false;
/* don't let anonymous logins override the name */
if (!name || !*name) {
return;
}
tmp = SMB_STRDUP(name);
if (!tmp) {
return;
}
trim_char(tmp, ' ', ' ');
strlower_m(tmp);
len = strlen(tmp);
if (len == 0) {
SAFE_FREE(tmp);
return;
}
/* long story but here goes....we have to allow usernames
ending in '$' as they are valid machine account names.
So check for a machine account and re-add the '$'
at the end after the call to alpha_strcpy(). --jerry */
if (tmp[len-1] == '$') {
is_machine_account = True;
}
SAFE_FREE(smb_user_name);
smb_user_name = SMB_CALLOC_ARRAY(char, len+1);
if (!smb_user_name) {
SAFE_FREE(tmp);
return;
}
/* alpha_strcpy includes the space for the terminating nul. */
alpha_strcpy(smb_user_name, tmp,
SAFE_NETBIOS_CHARS,
len+1);
SAFE_FREE(tmp);
if (is_machine_account) {
len = strlen(smb_user_name);
smb_user_name[len-1] = '$';
}
}
static const char *get_smb_user_name(void)
{
return smb_user_name ? smb_user_name : "";
}
/*******************************************************************
Setup the strings used by substitutions. Called per packet. Ensure
%U name is set correctly also.
smb_name must be sanitized by alpha_strcpy
********************************************************************/
void set_current_user_info(const char *smb_name, const char *unix_name,
const char *domain)
{
fstrcpy(current_user_info.smb_name, smb_name);
fstrcpy(current_user_info.unix_name, unix_name);
fstrcpy(current_user_info.domain, domain);
/* The following is safe as current_user_info.smb_name
* has already been sanitised in register_existing_vuid. */
sub_set_smb_name(current_user_info.smb_name);
}
/*******************************************************************
Return the current active user name.
*******************************************************************/
const char *get_current_username(void)
{
if (current_user_info.smb_name[0] == '\0' ) {
return get_smb_user_name();
}
return current_user_info.smb_name;
}
/*******************************************************************
Given a pointer to a %$(NAME) in p and the whole string in str
expand it as an environment variable.
Return a new allocated and expanded string.
Based on code by Branko Cibej <branko.cibej@hermes.si>
When this is called p points at the '%' character.
May substitute multiple occurrencies of the same env var.
********************************************************************/
static char * realloc_expand_env_var(char *str, char *p)
{
char *envname;
char *envval;
char *q, *r;
int copylen;
if (p[0] != '%' || p[1] != '$' || p[2] != '(') {
return str;
}
/*
* Look for the terminating ')'.
*/
if ((q = strchr_m(p,')')) == NULL) {
DEBUG(0,("expand_env_var: Unterminated environment variable [%s]\n", p));
return str;
}
/*
* Extract the name from within the %$(NAME) string.
*/
r = p + 3;
copylen = q - r;
/* reserve space for use later add %$() chars */
if ( (envname = (char *)SMB_MALLOC(copylen + 1 + 4)) == NULL ) {
return NULL;
}
strncpy(envname,r,copylen);
envname[copylen] = '\0';
if ((envval = getenv(envname)) == NULL) {
DEBUG(0,("expand_env_var: Environment variable [%s] not set\n", envname));
SAFE_FREE(envname);
return str;
}
/*
* Copy the full %$(NAME) into envname so it
* can be replaced.
*/
copylen = q + 1 - p;
strncpy(envname,p,copylen);
envname[copylen] = '\0';
r = realloc_string_sub(str, envname, envval);
SAFE_FREE(envname);
return r;
}
/*******************************************************************
*******************************************************************/
static char *longvar_domainsid( void )
{
DOM_SID sid;
fstring tmp;
char *sid_string;
if ( !secrets_fetch_domain_sid( lp_workgroup(), &sid ) ) {
return NULL;
}
sid_string = SMB_STRDUP( sid_to_fstring( tmp, &sid ) );
if ( !sid_string ) {
DEBUG(0,("longvar_domainsid: failed to dup SID string!\n"));
}
return sid_string;
}
/*******************************************************************
*******************************************************************/
struct api_longvar {
const char *name;
char* (*fn)( void );
};
static struct api_longvar longvar_table[] = {
{ "DomainSID", longvar_domainsid },
{ NULL, NULL }
};
static char *get_longvar_val( const char *varname )
{
int i;
DEBUG(7,("get_longvar_val: expanding variable [%s]\n", varname));
for ( i=0; longvar_table[i].name; i++ ) {
if ( strequal( longvar_table[i].name, varname ) ) {
return longvar_table[i].fn();
}
}
return NULL;
}
/*******************************************************************
Expand the long smb.conf variable names given a pointer to a %(NAME).
Return the number of characters by which the pointer should be advanced.
When this is called p points at the '%' character.
********************************************************************/
static char *realloc_expand_longvar(char *str, char *p)
{
fstring varname;
char *value;
char *q, *r;
int copylen;
if ( p[0] != '%' || p[1] != '(' ) {
return str;
}
/* Look for the terminating ')'.*/
if ((q = strchr_m(p,')')) == NULL) {
DEBUG(0,("realloc_expand_longvar: Unterminated environment variable [%s]\n", p));
return str;
}
/* Extract the name from within the %(NAME) string.*/
r = p+2;
copylen = MIN( (q-r), (sizeof(varname)-1) );
strncpy(varname, r, copylen);
varname[copylen] = '\0';
if ((value = get_longvar_val(varname)) == NULL) {
DEBUG(0,("realloc_expand_longvar: Variable [%s] not set. Skipping\n", varname));
return str;
}
/* Copy the full %(NAME) into envname so it can be replaced.*/
copylen = MIN( (q+1-p),(sizeof(varname)-1) );
strncpy( varname, p, copylen );
varname[copylen] = '\0';
r = realloc_string_sub(str, varname, value);
SAFE_FREE( value );
/* skip over the %(varname) */
return r;
}
/*******************************************************************
Patch from jkf@soton.ac.uk
Added this to implement %p (NIS auto-map version of %H)
*******************************************************************/
static const char *automount_path(const char *user_name)
{
TALLOC_CTX *ctx = talloc_tos();
const char *server_path;
/* use the passwd entry as the default */
/* this will be the default if WITH_AUTOMOUNT is not used or fails */
server_path = talloc_strdup(ctx, get_user_home_dir(ctx, user_name));
if (!server_path) {
return "";
}
#if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
if (lp_nis_home_map()) {
const char *home_path_start;
char *automount_value = automount_lookup(ctx, user_name);
if(automount_value && strlen(automount_value) > 0) {
home_path_start = strchr_m(automount_value,':');
if (home_path_start != NULL) {
DEBUG(5, ("NIS lookup succeeded. "
"Home path is: %s\n",
home_path_start ?
(home_path_start+1):""));
server_path = talloc_strdup(ctx,
home_path_start+1);
if (!server_path) {
server_path = "";
}
}
} else {
/* NIS key lookup failed: default to
* user home directory from password file */
DEBUG(5, ("NIS lookup failed. Using Home path from "
"passwd file. Home path is: %s\n", server_path ));
}
}
#endif
DEBUG(4,("Home server path: %s\n", server_path));
return server_path;
}
/*******************************************************************
Patch from jkf@soton.ac.uk
This is Luke's original function with the NIS lookup code
moved out to a separate function.
*******************************************************************/
static const char *automount_server(const char *user_name)
{
TALLOC_CTX *ctx = talloc_tos();
const char *server_name;
const char *local_machine_name = get_local_machine_name();
/* use the local machine name as the default */
/* this will be the default if WITH_AUTOMOUNT is not used or fails */
if (local_machine_name && *local_machine_name) {
server_name = talloc_strdup(ctx, local_machine_name);
} else {
server_name = talloc_strdup(ctx, global_myname());
}
if (!server_name) {
return "";
}
#if (defined(HAVE_NETGROUP) && defined (WITH_AUTOMOUNT))
if (lp_nis_home_map()) {
char *p;
char *srv;
char *automount_value = automount_lookup(ctx, user_name);
if (!automount_value) {
return "";
}
srv = talloc_strdup(ctx, automount_value);
if (!srv) {
return "";
}
p = strchr_m(srv, ':');
if (!p) {
return "";
}
*p = '\0';
server_name = srv;
DEBUG(5, ("NIS lookup succeeded. Home server %s\n",
server_name));
}
#endif
DEBUG(4,("Home server: %s\n", server_name));
return server_name;
}
/****************************************************************************
Do some standard substitutions in a string.
len is the length in bytes of the space allowed in string str. If zero means
don't allow expansions.
****************************************************************************/
void standard_sub_basic(const char *smb_name, const char *domain_name,
char *str, size_t len)
{
char *s;
if ( (s = alloc_sub_basic( smb_name, domain_name, str )) != NULL ) {
strncpy( str, s, len );
}
SAFE_FREE( s );
}
/****************************************************************************
Do some standard substitutions in a string.
This function will return an allocated string that have to be freed.
****************************************************************************/
char *talloc_sub_basic(TALLOC_CTX *mem_ctx, const char *smb_name,
const char *domain_name, const char *str)
{
char *a, *t;
if ( (a = alloc_sub_basic(smb_name, domain_name, str)) == NULL ) {
return NULL;
}
t = talloc_strdup(mem_ctx, a);
SAFE_FREE(a);
return t;
}
/****************************************************************************
****************************************************************************/
static char *alloc_sub_basic(const char *smb_name, const char *domain_name,
const char *str)
{
char *b, *p, *s, *r, *a_string;
fstring pidstr, vnnstr;
char addr[INET6_ADDRSTRLEN];
const char *local_machine_name = get_local_machine_name();
TALLOC_CTX *tmp_ctx = NULL;
/* workaround to prevent a crash while looking at bug #687 */
if (!str) {
DEBUG(0,("alloc_sub_basic: NULL source string! This should not happen\n"));
return NULL;
}
a_string = SMB_STRDUP(str);
if (a_string == NULL) {
DEBUG(0, ("alloc_sub_basic: Out of memory!\n"));
return NULL;
}
tmp_ctx = talloc_stackframe();
for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
r = NULL;
b = a_string;
switch (*(p+1)) {
case 'U' :
r = strlower_talloc(tmp_ctx, smb_name);
if (r == NULL) {
goto error;
}
a_string = realloc_string_sub(a_string, "%U", r);
break;
case 'G' : {
struct passwd *pass;
r = talloc_strdup(tmp_ctx, smb_name);
if (r == NULL) {
goto error;
}
pass = Get_Pwnam_alloc(tmp_ctx, r);
if (pass != NULL) {
a_string = realloc_string_sub(
a_string, "%G",
gidtoname(pass->pw_gid));
}
TALLOC_FREE(pass);
break;
}
case 'D' :
r = strupper_talloc(tmp_ctx, domain_name);
if (r == NULL) {
goto error;
}
a_string = realloc_string_sub(a_string, "%D", r);
break;
case 'I' : {
int offset = 0;
client_addr(get_client_fd(), addr, sizeof(addr));
if (strnequal(addr,"::ffff:",7)) {
offset = 7;
}
a_string = realloc_string_sub(a_string, "%I",
addr + offset);
break;
}
case 'i':
a_string = realloc_string_sub( a_string, "%i",
client_socket_addr(get_client_fd(), addr, sizeof(addr)) );
break;
case 'L' :
if ( StrnCaseCmp(p, "%LOGONSERVER%", strlen("%LOGONSERVER%")) == 0 ) {
break;
}
if (local_machine_name && *local_machine_name) {
a_string = realloc_string_sub(a_string, "%L", local_machine_name);
} else {
a_string = realloc_string_sub(a_string, "%L", global_myname());
}
break;
case 'N':
a_string = realloc_string_sub(a_string, "%N", automount_server(smb_name));
break;
case 'M' :
a_string = realloc_string_sub(a_string, "%M", client_name(get_client_fd()));
break;
case 'R' :
a_string = realloc_string_sub(a_string, "%R", remote_proto);
break;
case 'T' :
a_string = realloc_string_sub(a_string, "%T", current_timestring(tmp_ctx, False));
break;
case 'a' :
a_string = realloc_string_sub(a_string, "%a",
get_remote_arch_str());
break;
case 'd' :
slprintf(pidstr,sizeof(pidstr)-1, "%d",(int)sys_getpid());
a_string = realloc_string_sub(a_string, "%d", pidstr);
break;
case 'h' :
a_string = realloc_string_sub(a_string, "%h", myhostname());
break;
case 'm' :
a_string = realloc_string_sub(a_string, "%m",
remote_machine
? remote_machine
: "");
break;
case 'v' :
a_string = realloc_string_sub(a_string, "%v", samba_version_string());
break;
case 'w' :
a_string = realloc_string_sub(a_string, "%w", lp_winbind_separator());
break;
case '$' :
a_string = realloc_expand_env_var(a_string, p); /* Expand environment variables */
break;
case '(':
a_string = realloc_expand_longvar( a_string, p );
break;
case 'V' :
slprintf(vnnstr,sizeof(vnnstr)-1, "%u", get_my_vnn());
a_string = realloc_string_sub(a_string, "%V", vnnstr);
break;
default:
break;
}
p++;
TALLOC_FREE(r);
if (a_string == NULL) {
goto done;
}
}
goto done;
error:
SAFE_FREE(a_string);
done:
TALLOC_FREE(tmp_ctx);
return a_string;
}
/****************************************************************************
Do some specific substitutions in a string.
This function will return an allocated string that have to be freed.
****************************************************************************/
char *talloc_sub_specified(TALLOC_CTX *mem_ctx,
const char *input_string,
const char *username,
const char *domain,
uid_t uid,
gid_t gid)
{
char *a_string;
char *ret_string = NULL;
char *b, *p, *s;
TALLOC_CTX *tmp_ctx;
if (!(tmp_ctx = talloc_new(mem_ctx))) {
DEBUG(0, ("talloc_new failed\n"));
return NULL;
}
a_string = talloc_strdup(tmp_ctx, input_string);
if (a_string == NULL) {
DEBUG(0, ("talloc_sub_specified: Out of memory!\n"));
goto done;
}
for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
b = a_string;
switch (*(p+1)) {
case 'U' :
a_string = talloc_string_sub(
tmp_ctx, a_string, "%U", username);
break;
case 'u' :
a_string = talloc_string_sub(
tmp_ctx, a_string, "%u", username);
break;
case 'G' :
if (gid != -1) {
a_string = talloc_string_sub(
tmp_ctx, a_string, "%G",
gidtoname(gid));
} else {
a_string = talloc_string_sub(
tmp_ctx, a_string,
"%G", "NO_GROUP");
}
break;
case 'g' :
if (gid != -1) {
a_string = talloc_string_sub(
tmp_ctx, a_string, "%g",
gidtoname(gid));
} else {
a_string = talloc_string_sub(
tmp_ctx, a_string, "%g", "NO_GROUP");
}
break;
case 'D' :
a_string = talloc_string_sub(tmp_ctx, a_string,
"%D", domain);
break;
case 'N' :
a_string = talloc_string_sub(
tmp_ctx, a_string, "%N",
automount_server(username));
break;
default:
break;
}
p++;
if (a_string == NULL) {
goto done;
}
}
/* Watch out, using "mem_ctx" here, so all intermediate stuff goes
* away with the TALLOC_FREE(tmp_ctx) further down. */
ret_string = talloc_sub_basic(mem_ctx, username, domain, a_string);
done:
TALLOC_FREE(tmp_ctx);
return ret_string;
}
/****************************************************************************
****************************************************************************/
static char *alloc_sub_advanced(const char *servicename, const char *user,
const char *connectpath, gid_t gid,
const char *smb_name, const char *domain_name,
const char *str)
{
char *a_string, *ret_string;
char *b, *p, *s;
a_string = SMB_STRDUP(str);
if (a_string == NULL) {
DEBUG(0, ("alloc_sub_advanced: Out of memory!\n"));
return NULL;
}
for (b = s = a_string; (p = strchr_m(s, '%')); s = a_string + (p - b)) {
b = a_string;
switch (*(p+1)) {
case 'N' :
a_string = realloc_string_sub(a_string, "%N", automount_server(user));
break;
case 'H': {
char *h;
if ((h = get_user_home_dir(talloc_tos(), user)))
a_string = realloc_string_sub(a_string, "%H", h);
TALLOC_FREE(h);
break;
}
case 'P':
a_string = realloc_string_sub(a_string, "%P", connectpath);
break;
case 'S':
a_string = realloc_string_sub(a_string, "%S", servicename);
break;
case 'g':
a_string = realloc_string_sub(a_string, "%g", gidtoname(gid));
break;
case 'u':
a_string = realloc_string_sub(a_string, "%u", user);
break;
/* Patch from jkf@soton.ac.uk Left the %N (NIS
* server name) in standard_sub_basic as it is
* a feature for logon servers, hence uses the
* username. The %p (NIS server path) code is
* here as it is used instead of the default
* "path =" string in [homes] and so needs the
* service name, not the username. */
case 'p':
a_string = realloc_string_sub(a_string, "%p",
automount_path(servicename));
break;
default:
break;
}
p++;
if (a_string == NULL) {
return NULL;
}
}
ret_string = alloc_sub_basic(smb_name, domain_name, a_string);
SAFE_FREE(a_string);
return ret_string;
}
/*
* This obviously is inefficient and needs to be merged into
* alloc_sub_advanced...
*/
char *talloc_sub_advanced(TALLOC_CTX *mem_ctx,
const char *servicename, const char *user,
const char *connectpath, gid_t gid,
const char *smb_name, const char *domain_name,
const char *str)
{
char *a, *t;
if (!(a = alloc_sub_advanced(servicename, user, connectpath, gid,
smb_name, domain_name, str))) {
return NULL;
}
t = talloc_strdup(mem_ctx, a);
SAFE_FREE(a);
return t;
}
void standard_sub_advanced(const char *servicename, const char *user,
const char *connectpath, gid_t gid,
const char *smb_name, const char *domain_name,
char *str, size_t len)
{
char *s;
s = alloc_sub_advanced(servicename, user, connectpath,
gid, smb_name, domain_name, str);
if ( s ) {
strncpy( str, s, len );
SAFE_FREE( s );
}
}
/****************************************************************************
Do some standard substitutions in a string.
****************************************************************************/
char *standard_sub_conn(TALLOC_CTX *ctx, connection_struct *conn, const char *str)
{
return talloc_sub_advanced(ctx,
lp_servicename(SNUM(conn)),
conn->server_info->unix_name,
conn->connectpath,
conn->server_info->utok.gid,
get_smb_user_name(),
"",
str);
}