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/*
Unix SMB/Netbios implementation.
Version 2.0
winbind client common code
Copyright (C) Tim Potter 2000
Copyright (C) Andrew Tridgell 2000
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_nss_config.h"
#include "winbindd_nss.h"
/* Global variables. These are effectively the client state information */
static int established_socket = -1; /* fd for winbindd socket */
/*
* Utility and helper functions
*/
void init_request(struct winbindd_request *req,int rq_type)
{
static char *domain_env;
static BOOL initialised;
req->cmd = rq_type;
req->pid = getpid();
req->domain[0] = '\0';
if (!initialised) {
initialised = True;
domain_env = getenv(WINBINDD_DOMAIN_ENV);
}
if (domain_env) {
strncpy(req->domain, domain_env,
sizeof(req->domain) - 1);
req->domain[sizeof(req->domain) - 1] = '\0';
}
}
/* Close established socket */
void close_sock(void)
{
if (established_socket != -1) {
close(established_socket);
established_socket = -1;
}
}
/* Connect to winbindd socket */
static int open_pipe_sock(void)
{
struct sockaddr_un sunaddr;
static pid_t our_pid;
struct stat st;
pstring path;
if (our_pid != getpid()) {
if (established_socket != -1) {
close(established_socket);
}
established_socket = -1;
our_pid = getpid();
}
if (established_socket != -1) {
return established_socket;
}
/* Check permissions on unix socket directory */
if (lstat(WINBINDD_SOCKET_DIR, &st) == -1) {
return -1;
}
if (!S_ISDIR(st.st_mode) || (st.st_uid != 0)) {
return -1;
}
/* Connect to socket */
strncpy(path, WINBINDD_SOCKET_DIR, sizeof(path) - 1);
path[sizeof(path) - 1] = '\0';
strncat(path, "/", sizeof(path) - 1);
path[sizeof(path) - 1] = '\0';
strncat(path, WINBINDD_SOCKET_NAME, sizeof(path) - 1);
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)) {
return -1;
}
/* Connect to socket */
if ((established_socket = socket(AF_UNIX, SOCK_STREAM, 0)) == -1) {
return -1;
}
if (connect(established_socket, (struct sockaddr *)&sunaddr,
sizeof(sunaddr)) == -1) {
close_sock();
return -1;
}
return established_socket;
}
/* Write data to winbindd socket with timeout */
int write_sock(void *buffer, int count)
{
int result, nwritten;
/* Open connection to winbind daemon */
restart:
if (open_pipe_sock() == -1) {
return -1;
}
/* Write data to socket */
nwritten = 0;
while(nwritten < count) {
struct timeval tv;
fd_set r_fds;
int selret;
/* Catch pipe close on other end by checking if a read()
call would not block by calling select(). */
FD_ZERO(&r_fds);
FD_SET(established_socket, &r_fds);
ZERO_STRUCT(tv);
if ((selret = select(established_socket + 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(established_socket, &r_fds)) {
/* Do the write */
result = write(established_socket,
(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 with timeout */
static int read_sock(void *buffer, int count)
{
int result = 0, nread = 0;
/* Read data from socket */
while(nread < count) {
result = read(established_socket, (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 = 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 = malloc(extra_data_len))) {
return -1;
}
if ((result2 = read_sock(response->extra_data, extra_data_len))
== -1) {
return -1;
}
}
/* Return total amount of data read */
return result1 + result2;
}
/* Free a response structure */
void free_response(struct winbindd_response *response)
{
/* Free any allocated extra_data */
if (response && response->extra_data) {
free(response->extra_data);
response->extra_data = NULL;
}
}
/* Handle simple types of requests */
enum nss_status generic_request(int req_type,
struct winbindd_request *request,
struct winbindd_response *response)
{
struct winbindd_request lrequest;
struct winbindd_response lresponse;
/* Check for our tricky environment variable */
if (getenv(WINBINDD_DONT_ENV)) {
return NSS_STATUS_NOTFOUND;
}
if (!response) {
ZERO_STRUCT(lresponse);
response = &lresponse;
}
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)) == -1) {
return NSS_STATUS_UNAVAIL;
}
/* 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;
}
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