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/*
Unix SMB/CIFS implementation.
winbind client common code
Copyright (C) Tim Potter 2000
Copyright (C) Andrew Tridgell 2000
Copyright (C) Andrew Bartlett 2002
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library 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
Library General Public License for more details.
You should have received a copy of the GNU Library General Public
License along with this library; if not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
*/
#include "winbind_client.h"
/* Global variables. These are effectively the client state information */
int winbindd_fd = -1; /* fd for winbindd socket */
/* Free a response structure */
void free_response(struct winbindd_response *response)
{
/* Free any allocated extra_data */
if (response)
SAFE_FREE(response->extra_data.data);
}
/* Initialise a request structure */
void init_request(struct winbindd_request *request, int request_type)
{
request->length = sizeof(struct winbindd_request);
request->cmd = (enum winbindd_cmd)request_type;
request->pid = getpid();
}
/* Initialise a response structure */
void init_response(struct winbindd_response *response)
{
/* Initialise return value */
response->result = WINBINDD_ERROR;
}
/* Close established socket */
void close_sock(void)
{
if (winbindd_fd != -1) {
close(winbindd_fd);
winbindd_fd = -1;
}
}
#define CONNECT_TIMEOUT 30
#define WRITE_TIMEOUT CONNECT_TIMEOUT
#define READ_TIMEOUT CONNECT_TIMEOUT
/* Make sure socket handle isn't stdin, stdout or stderr */
#define RECURSION_LIMIT 3
static int make_nonstd_fd_internals(int fd, int limit /* Recursion limiter */)
{
int new_fd;
if (fd >= 0 && fd <= 2) {
#ifdef F_DUPFD
if ((new_fd = fcntl(fd, F_DUPFD, 3)) == -1) {
return -1;
}
/* Paranoia */
if (new_fd < 3) {
close(new_fd);
return -1;
}
close(fd);
return new_fd;
#else
if (limit <= 0)
return -1;
new_fd = dup(fd);
if (new_fd == -1)
return -1;
/* use the program stack to hold our list of FDs to close */
new_fd = make_nonstd_fd_internals(new_fd, limit - 1);
close(fd);
return new_fd;
#endif
}
return fd;
}
/****************************************************************************
Set a fd into blocking/nonblocking mode. Uses POSIX O_NONBLOCK if available,
else
if SYSV use O_NDELAY
if BSD use FNDELAY
Set close on exec also.
****************************************************************************/
static int make_safe_fd(int fd)
{
int result, flags;
int new_fd = make_nonstd_fd_internals(fd, RECURSION_LIMIT);
if (new_fd == -1) {
close(fd);
return -1;
}
/* Socket should be nonblocking. */
#ifdef O_NONBLOCK
#define FLAG_TO_SET O_NONBLOCK
#else
#ifdef SYSV
#define FLAG_TO_SET O_NDELAY
#else /* BSD */
#define FLAG_TO_SET FNDELAY
#endif
#endif
if ((flags = fcntl(new_fd, F_GETFL)) == -1) {
close(new_fd);
return -1;
}
flags |= FLAG_TO_SET;
if (fcntl(new_fd, F_SETFL, flags) == -1) {
close(new_fd);
return -1;
}
#undef FLAG_TO_SET
/* Socket should be closed on exec() */
#ifdef FD_CLOEXEC
result = flags = fcntl(new_fd, F_GETFD, 0);
if (flags >= 0) {
flags |= FD_CLOEXEC;
result = fcntl( new_fd, F_SETFD, flags );
}
if (result < 0) {
close(new_fd);
return -1;
}
#endif
return new_fd;
}
/* Connect to winbindd socket */
static int winbind_named_pipe_sock(const char *dir)
{
struct sockaddr_un sunaddr;
struct stat st;
pstring path;
int fd;
int wait_time;
int slept;
/* Check permissions on unix socket directory */
if (lstat(dir, &st) == -1) {
return -1;
}
if (!S_ISDIR(st.st_mode) ||
(st.st_uid != 0 && st.st_uid != geteuid())) {
return -1;
}
/* Connect to socket */
strncpy(path, dir, sizeof(path) - 1);
path[sizeof(path) - 1] = '\0';
strncat(path, "/", sizeof(path) - 1 - strlen(path));
path[sizeof(path) - 1] = '\0';
strncat(path, WINBINDD_SOCKET_NAME, sizeof(path) - 1 - strlen(path));
path[sizeof(path) - 1] = '\0';
ZERO_STRUCT(sunaddr);
sunaddr.sun_family = AF_UNIX;
strncpy(sunaddr.sun_path, path, sizeof(sunaddr.sun_path) - 1);
/* If socket file doesn't exist, don't bother trying to connect
with retry. This is an attempt to make the system usable when
the winbindd daemon is not running. */
if (lstat(path, &st) == -1) {
return -1;
}
/* Check permissions on unix socket file */
if (!S_ISSOCK(st.st_mode) ||
(st.st_uid != 0 && st.st_uid != geteuid())) {
return -1;
}
/* Connect to socket */
if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
return -1;
}
/* Set socket non-blocking and close on exec. */
if ((fd = make_safe_fd( fd)) == -1) {
return fd;
}
for (wait_time = 0; connect(fd, (struct sockaddr *)&sunaddr, sizeof(sunaddr)) == -1;
wait_time += slept) {
struct timeval tv;
fd_set w_fds;
int ret;
int connect_errno = 0;
socklen_t errnosize;
if (wait_time >= CONNECT_TIMEOUT)
goto error_out;
switch (errno) {
case EINPROGRESS:
FD_ZERO(&w_fds);
FD_SET(fd, &w_fds);
tv.tv_sec = CONNECT_TIMEOUT - wait_time;
tv.tv_usec = 0;
ret = select(fd + 1, NULL, &w_fds, NULL, &tv);
if (ret > 0) {
errnosize = sizeof(connect_errno);
ret = getsockopt(fd, SOL_SOCKET,
SO_ERROR, &connect_errno, &errnosize);
if (ret >= 0 && connect_errno == 0) {
/* Connect succeed */
goto out;
}
}
slept = CONNECT_TIMEOUT;
break;
case EAGAIN:
slept = rand() % 3 + 1;
sleep(slept);
break;
default:
goto error_out;
}
}
out:
return fd;
error_out:
close(fd);
return -1;
}
/* Connect to winbindd socket */
static int winbind_open_pipe_sock(int recursing)
{
#ifdef HAVE_UNIXSOCKET
static pid_t our_pid;
struct winbindd_request request;
struct winbindd_response response;
ZERO_STRUCT(request);
ZERO_STRUCT(response);
if (our_pid != getpid()) {
close_sock();
our_pid = getpid();
}
if (winbindd_fd != -1) {
return winbindd_fd;
}
if (recursing) {
return -1;
}
if ((winbindd_fd = winbind_named_pipe_sock(WINBINDD_SOCKET_DIR)) == -1) {
return -1;
}
/* version-check the socket */
request.flags = WBFLAG_RECURSE;
if ((winbindd_request_response(WINBINDD_INTERFACE_VERSION, &request, &response) != NSS_STATUS_SUCCESS) || (response.data.interface_version != WINBIND_INTERFACE_VERSION)) {
close_sock();
return -1;
}
/* try and get priv pipe */
request.flags = WBFLAG_RECURSE;
if (winbindd_request_response(WINBINDD_PRIV_PIPE_DIR, &request, &response) == NSS_STATUS_SUCCESS) {
int fd;
if ((fd = winbind_named_pipe_sock((char *)response.extra_data.data)) != -1) {
close(winbindd_fd);
winbindd_fd = fd;
}
}
SAFE_FREE(response.extra_data.data);
return winbindd_fd;
#else
return -1;
#endif /* HAVE_UNIXSOCKET */
}
/* Write data to winbindd socket */
int write_sock(void *buffer, int count, int recursing)
{
int result, nwritten;
/* Open connection to winbind daemon */
restart:
if (winbind_open_pipe_sock(recursing) == -1) {
return -1;
}
/* Write data to socket */
nwritten = 0;
while(nwritten < count) {
struct timeval tv;
fd_set r_fds;
/* Catch pipe close on other end by checking if a read()
call would not block by calling select(). */
FD_ZERO(&r_fds);
FD_SET(winbindd_fd, &r_fds);
ZERO_STRUCT(tv);
if (select(winbindd_fd + 1, &r_fds, NULL, NULL, &tv) == -1) {
close_sock();
return -1; /* Select error */
}
/* Write should be OK if fd not available for reading */
if (!FD_ISSET(winbindd_fd, &r_fds)) {
/* Do the write */
result = write(winbindd_fd,
(char *)buffer + nwritten,
count - nwritten);
if ((result == -1) || (result == 0)) {
/* Write failed */
close_sock();
return -1;
}
nwritten += result;
} else {
/* Pipe has closed on remote end */
close_sock();
goto restart;
}
}
return nwritten;
}
/* Read data from winbindd socket */
static int read_sock(void *buffer, int count)
{
int result = 0, nread = 0;
int total_time = 0, selret;
if (winbindd_fd == -1) {
return -1;
}
/* Read data from socket */
while(nread < count) {
struct timeval tv;
fd_set r_fds;
/* Catch pipe close on other end by checking if a read()
call would not block by calling select(). */
FD_ZERO(&r_fds);
FD_SET(winbindd_fd, &r_fds);
ZERO_STRUCT(tv);
/* Wait for 5 seconds for a reply. May need to parameterise this... */
tv.tv_sec = 5;
if ((selret = select(winbindd_fd + 1, &r_fds, NULL, NULL, &tv)) == -1) {
close_sock();
return -1; /* Select error */
}
if (selret == 0) {
/* Not ready for read yet... */
if (total_time >= 30) {
/* Timeout */
close_sock();
return -1;
}
total_time += 5;
continue;
}
if (FD_ISSET(winbindd_fd, &r_fds)) {
/* Do the Read */
result = read(winbindd_fd, (char *)buffer + nread,
count - nread);
if ((result == -1) || (result == 0)) {
/* Read failed. I think the only useful thing we
can do here is just return -1 and fail since the
transaction has failed half way through. */
close_sock();
return -1;
}
nread += result;
}
}
return result;
}
/* Read reply */
int read_reply(struct winbindd_response *response)
{
int result1, result2 = 0;
if (!response) {
return -1;
}
/* Read fixed length response */
if ((result1 = read_sock(response, sizeof(struct winbindd_response)))
== -1) {
return -1;
}
/* We actually send the pointer value of the extra_data field from
the server. This has no meaning in the client's address space
so we clear it out. */
response->extra_data.data = NULL;
/* Read variable length response */
if (response->length > sizeof(struct winbindd_response)) {
int extra_data_len = response->length -
sizeof(struct winbindd_response);
/* Mallocate memory for extra data */
if (!(response->extra_data.data = malloc(extra_data_len))) {
return -1;
}
if ((result2 = read_sock(response->extra_data.data, extra_data_len))
== -1) {
free_response(response);
return -1;
}
}
/* Return total amount of data read */
return result1 + result2;
}
/*
* send simple types of requests
*/
NSS_STATUS winbindd_send_request(int req_type, struct winbindd_request *request)
{
struct winbindd_request lrequest;
/* Check for our tricky environment variable */
if (winbind_env_set()) {
return NSS_STATUS_NOTFOUND;
}
if (!request) {
ZERO_STRUCT(lrequest);
request = &lrequest;
}
/* Fill in request and send down pipe */
init_request(request, req_type);
if (write_sock(request, sizeof(*request), request->flags & WBFLAG_RECURSE) == -1) {
return NSS_STATUS_UNAVAIL;
}
if ((request->extra_len != 0) &&
(write_sock(request->extra_data.data, request->extra_len, request->flags & WBFLAG_RECURSE) == -1)) {
return NSS_STATUS_UNAVAIL;
}
return NSS_STATUS_SUCCESS;
}
/*
* Get results from winbindd request
*/
NSS_STATUS winbindd_get_response(struct winbindd_response *response)
{
struct winbindd_response lresponse;
if (!response) {
ZERO_STRUCT(lresponse);
response = &lresponse;
}
init_response(response);
/* Wait for reply */
if (read_reply(response) == -1) {
return NSS_STATUS_UNAVAIL;
}
/* Throw away extra data if client didn't request it */
if (response == &lresponse) {
free_response(response);
}
/* Copy reply data from socket */
if (response->result != WINBINDD_OK) {
return NSS_STATUS_NOTFOUND;
}
return NSS_STATUS_SUCCESS;
}
/* Handle simple types of requests */
NSS_STATUS winbindd_request_response(int req_type,
struct winbindd_request *request,
struct winbindd_response *response)
{
NSS_STATUS status = NSS_STATUS_UNAVAIL;
int count = 0;
while ((status == NSS_STATUS_UNAVAIL) && (count < 10)) {
status = winbindd_send_request(req_type, request);
if (status != NSS_STATUS_SUCCESS)
return(status);
status = winbindd_get_response(response);
count += 1;
}
return status;
}
/*************************************************************************
A couple of simple functions to disable winbindd lookups and re-
enable them
************************************************************************/
/* Use putenv() instead of setenv() in these functions as not all
environments have the latter. */
BOOL winbind_off( void )
{
static char *s = CONST_DISCARD(char *, WINBINDD_DONT_ENV "=1");
return putenv(s) != -1;
}
BOOL winbind_on( void )
{
static char *s = CONST_DISCARD(char *, WINBINDD_DONT_ENV "=0");
return putenv(s) != -1;
}
BOOL winbind_env_set( void )
{
char *env;
if ((env=getenv(WINBINDD_DONT_ENV)) != NULL) {
if(strequal(env, "1")) {
return True;
}
}
return False;
}
|