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samba-mirror/source4/kdc/kdc.c
Andrew Bartlett a8e69328bf r11106: Make the KDC handler plugable, as I want to drop kpasswdd into exactly
the same spot (it has identical TCP sementics).

Andrew Bartlett
(This used to be commit 84d6118e87)
2007-10-10 13:44:50 -05:00

601 lines
16 KiB
C

/*
Unix SMB/CIFS implementation.
KDC Server startup
Copyright (C) Andrew Bartlett <abartlet@samba.org> 2005
Copyright (C) Andrew Tridgell 2005
Copyright (C) Stefan Metzmacher 2005
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include "includes.h"
#include "smbd/service_task.h"
#include "smbd/service_stream.h"
#include "lib/events/events.h"
#include "lib/socket/socket.h"
#include "kdc/kdc.h"
#include "system/network.h"
#include "dlinklist.h"
#include "lib/messaging/irpc.h"
/* hold all the info needed to send a reply */
struct kdc_reply {
struct kdc_reply *next, *prev;
const char *dest_address;
int dest_port;
DATA_BLOB packet;
};
/*
top level context structure for the kdc server
*/
struct kdc_server {
struct task_server *task;
krb5_kdc_configuration *config;
struct smb_krb5_context *smb_krb5_context;
};
/* hold information about one kdc socket */
struct kdc_socket {
struct socket_context *sock;
struct kdc_server *kdc;
struct fd_event *fde;
/* a queue of outgoing replies that have been deferred */
struct kdc_reply *send_queue;
int (*process)(krb5_context context,
krb5_kdc_configuration *config,
unsigned char *buf,
size_t len,
krb5_data *reply,
const char *from,
struct sockaddr *addr);
};
/*
state of an open tcp connection
*/
struct kdc_tcp_connection {
/* stream connection we belong to */
struct stream_connection *conn;
/* the kdc_server the connection belongs to */
struct kdc_server *kdc;
/* the partial data we've receiced yet */
DATA_BLOB partial;
/* the amount that we used yet from the partial buffer */
uint32_t partial_read;
/* prevent loops when we use half async code, while processing a requuest */
BOOL processing;
/* a queue of outgoing replies that have been deferred */
struct data_blob_list_item *send_queue;
int (*process)(krb5_context context,
krb5_kdc_configuration *config,
unsigned char *buf,
size_t len,
krb5_data *reply,
const char *from,
struct sockaddr *addr);
};
/*
handle fd send events on a KDC socket
*/
static void kdc_send_handler(struct kdc_socket *kdc_socket)
{
while (kdc_socket->send_queue) {
struct kdc_reply *rep = kdc_socket->send_queue;
NTSTATUS status;
size_t sendlen;
status = socket_sendto(kdc_socket->sock, &rep->packet, &sendlen, 0,
rep->dest_address, rep->dest_port);
if (NT_STATUS_EQUAL(status, STATUS_MORE_ENTRIES)) {
break;
}
DLIST_REMOVE(kdc_socket->send_queue, rep);
talloc_free(rep);
}
if (kdc_socket->send_queue == NULL) {
EVENT_FD_NOT_WRITEABLE(kdc_socket->fde);
}
}
/*
handle fd recv events on a KDC socket
*/
static void kdc_recv_handler(struct kdc_socket *kdc_socket)
{
NTSTATUS status;
TALLOC_CTX *tmp_ctx = talloc_new(kdc_socket);
DATA_BLOB blob;
struct kdc_reply *rep;
krb5_data reply;
size_t nread, dsize;
const char *src_addr;
int src_port;
struct sockaddr_in src_sock_addr;
struct ipv4_addr addr;
int ret;
status = socket_pending(kdc_socket->sock, &dsize);
if (!NT_STATUS_IS_OK(status)) {
talloc_free(tmp_ctx);
return;
}
blob = data_blob_talloc(kdc_socket, NULL, dsize);
if (blob.data == NULL) {
/* hope this is a temporary low memory condition */
talloc_free(tmp_ctx);
return;
}
status = socket_recvfrom(kdc_socket->sock, blob.data, blob.length, &nread, 0,
&src_addr, &src_port);
if (!NT_STATUS_IS_OK(status)) {
talloc_free(tmp_ctx);
return;
}
talloc_steal(tmp_ctx, src_addr);
blob.length = nread;
DEBUG(2,("Received krb5 UDP packet of length %u from %s:%u\n",
blob.length, src_addr, (uint16_t)src_port));
/* TODO: This really should be in a utility function somewhere */
ZERO_STRUCT(src_sock_addr);
#ifdef HAVE_SOCK_SIN_LEN
src_sock_addr.sin_len = sizeof(src_sock_addr);
#endif
addr = interpret_addr2(src_addr);
src_sock_addr.sin_addr.s_addr = addr.addr;
src_sock_addr.sin_port = htons(src_port);
src_sock_addr.sin_family = PF_INET;
/* Call krb5 */
ret = kdc_socket->process(kdc_socket->kdc->smb_krb5_context->krb5_context,
kdc_socket->kdc->config,
blob.data, blob.length,
&reply,
src_addr,
(struct sockaddr *)&src_sock_addr);
if (ret == -1) {
talloc_free(tmp_ctx);
return;
}
/* queue a pending reply */
rep = talloc(kdc_socket, struct kdc_reply);
if (rep == NULL) {
krb5_data_free(&reply);
talloc_free(tmp_ctx);
return;
}
rep->dest_address = talloc_steal(rep, src_addr);
rep->dest_port = src_port;
rep->packet = data_blob_talloc(rep, reply.data, reply.length);
krb5_data_free(&reply);
if (rep->packet.data == NULL) {
talloc_free(rep);
talloc_free(tmp_ctx);
return;
}
DLIST_ADD_END(kdc_socket->send_queue, rep, struct kdc_reply *);
EVENT_FD_WRITEABLE(kdc_socket->fde);
talloc_free(tmp_ctx);
}
/*
handle fd events on a KDC socket
*/
static void kdc_socket_handler(struct event_context *ev, struct fd_event *fde,
uint16_t flags, void *private)
{
struct kdc_socket *kdc_socket = talloc_get_type(private, struct kdc_socket);
if (flags & EVENT_FD_WRITE) {
kdc_send_handler(kdc_socket);
}
if (flags & EVENT_FD_READ) {
kdc_recv_handler(kdc_socket);
}
}
static void kdc_tcp_terminate_connection(struct kdc_tcp_connection *kdcconn, const char *reason)
{
stream_terminate_connection(kdcconn->conn, reason);
}
/*
called when we get a new connection
*/
static void kdc_tcp_accept(struct stream_connection *conn)
{
struct kdc_server *kdc = talloc_get_type(conn->private, struct kdc_server);
struct kdc_tcp_connection *kdcconn;
kdcconn = talloc_zero(conn, struct kdc_tcp_connection);
if (!kdcconn) {
stream_terminate_connection(conn, "kdc_tcp_accept: out of memory");
return;
}
kdcconn->conn = conn;
kdcconn->kdc = kdc;
kdcconn->process = krb5_kdc_process_krb5_request;
conn->private = kdcconn;
}
/*
receive some data on a KDC connection
*/
static void kdc_tcp_recv(struct stream_connection *conn, uint16_t flags)
{
struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private, struct kdc_tcp_connection);
NTSTATUS status = NT_STATUS_UNSUCCESSFUL;
TALLOC_CTX *tmp_ctx = talloc_new(kdcconn);
struct data_blob_list_item *rep;
krb5_data reply;
size_t nread;
const char *src_addr;
int src_port;
struct sockaddr_in src_sock_addr;
struct ipv4_addr addr;
int ret;
/* avoid recursion, because of half async code */
if (kdcconn->processing) {
EVENT_FD_NOT_READABLE(conn->event.fde);
return;
}
if (kdcconn->partial.length == 0) {
kdcconn->partial = data_blob_talloc(kdcconn, NULL, 4);
if (!kdcconn->partial.data) goto nomem;
kdcconn->partial_read = 0;
}
/* read in the packet length */
if (kdcconn->partial_read < 4) {
uint32_t packet_length;
status = socket_recv(conn->socket,
kdcconn->partial.data + kdcconn->partial_read,
4 - kdcconn->partial_read,
&nread, 0);
if (NT_STATUS_IS_ERR(status)) goto failed;
if (!NT_STATUS_IS_OK(status)) return;
kdcconn->partial_read += nread;
if (kdcconn->partial_read != 4) return;
packet_length = RIVAL(kdcconn->partial.data, 0) + 4;
kdcconn->partial.data = talloc_realloc(kdcconn, kdcconn->partial.data,
uint8_t, packet_length);
if (!kdcconn->partial.data) goto nomem;
kdcconn->partial.length = packet_length;
}
/* read in the body */
status = socket_recv(conn->socket,
kdcconn->partial.data + kdcconn->partial_read,
kdcconn->partial.length - kdcconn->partial_read,
&nread, 0);
if (NT_STATUS_IS_ERR(status)) goto failed;
if (!NT_STATUS_IS_OK(status)) return;
kdcconn->partial_read += nread;
if (kdcconn->partial_read != kdcconn->partial.length) return;
/*
* we have parsed the request, so we can reset the kdcconn->partial_read,
* maybe we could also free kdcconn->partial, but for now we keep it,
* and overwrite it the next time
*/
kdcconn->partial_read = 0;
src_addr = socket_get_peer_addr(kdcconn->conn->socket, tmp_ctx);
if (!src_addr) goto nomem;
src_port = socket_get_peer_port(kdcconn->conn->socket);
DEBUG(2,("Received krb5 TCP packet of length %u from %s:%u\n",
kdcconn->partial.length - 4, src_addr, src_port));
/* TODO: This really should be in a utility function somewhere */
ZERO_STRUCT(src_sock_addr);
#ifdef HAVE_SOCK_SIN_LEN
src_sock_addr.sin_len = sizeof(src_sock_addr);
#endif
addr = interpret_addr2(src_addr);
src_sock_addr.sin_addr.s_addr = addr.addr;
src_sock_addr.sin_port = htons(src_port);
src_sock_addr.sin_family = PF_INET;
/* Call krb5 */
kdcconn->processing = True;
ret = kdcconn->process(kdcconn->kdc->smb_krb5_context->krb5_context,
kdcconn->kdc->config,
kdcconn->partial.data + 4, kdcconn->partial.length - 4,
&reply,
src_addr,
(struct sockaddr *)&src_sock_addr);
kdcconn->processing = False;
if (ret == -1) {
status = NT_STATUS_INTERNAL_ERROR;
goto failed;
}
/* and now encode the reply */
rep = talloc(kdcconn, struct data_blob_list_item);
if (!rep) {
krb5_data_free(&reply);
goto nomem;
}
rep->blob = data_blob_talloc(rep, NULL, reply.length + 4);
if (!rep->blob.data) {
krb5_data_free(&reply);
goto nomem;
}
RSIVAL(rep->blob.data, 0, reply.length);
memcpy(rep->blob.data + 4, reply.data, reply.length);
krb5_data_free(&reply);
if (!kdcconn->send_queue) {
EVENT_FD_WRITEABLE(kdcconn->conn->event.fde);
}
DLIST_ADD_END(kdcconn->send_queue, rep, struct data_blob_list_item *);
EVENT_FD_READABLE(kdcconn->conn->event.fde);
/* the call isn't needed any more */
talloc_free(tmp_ctx);
return;
nomem:
status = NT_STATUS_NO_MEMORY;
failed:
kdc_tcp_terminate_connection(kdcconn, nt_errstr(status));
}
/*
called when we can write to a connection
*/
static void kdc_tcp_send(struct stream_connection *conn, uint16_t flags)
{
struct kdc_tcp_connection *kdcconn = talloc_get_type(conn->private, struct kdc_tcp_connection);
NTSTATUS status;
while (kdcconn->send_queue) {
struct data_blob_list_item *q = kdcconn->send_queue;
size_t sendlen;
status = socket_send(conn->socket, &q->blob, &sendlen, 0);
if (NT_STATUS_IS_ERR(status)) goto failed;
if (!NT_STATUS_IS_OK(status)) return;
q->blob.length -= sendlen;
q->blob.data += sendlen;
if (q->blob.length == 0) {
DLIST_REMOVE(kdcconn->send_queue, q);
talloc_free(q);
}
}
EVENT_FD_NOT_WRITEABLE(conn->event.fde);
return;
failed:
kdc_tcp_terminate_connection(kdcconn, nt_errstr(status));
}
static const struct stream_server_ops kdc_tcp_stream_ops = {
.name = "kdc_tcp",
.accept_connection = kdc_tcp_accept,
.recv_handler = kdc_tcp_recv,
.send_handler = kdc_tcp_send
};
/*
start listening on the given address
*/
static NTSTATUS kdc_add_socket(struct kdc_server *kdc, const char *address)
{
const struct model_ops *model_ops;
struct kdc_socket *kdc_socket;
NTSTATUS status;
uint16_t port = lp_krb5_port();
kdc_socket = talloc(kdc, struct kdc_socket);
NT_STATUS_HAVE_NO_MEMORY(kdc_socket);
status = socket_create("ip", SOCKET_TYPE_DGRAM, &kdc_socket->sock, 0);
if (!NT_STATUS_IS_OK(status)) {
talloc_free(kdc_socket);
return status;
}
kdc_socket->kdc = kdc;
kdc_socket->send_queue = NULL;
kdc_socket->process = krb5_kdc_process_krb5_request;
talloc_steal(kdc_socket, kdc_socket->sock);
kdc_socket->fde = event_add_fd(kdc->task->event_ctx, kdc,
socket_get_fd(kdc_socket->sock), EVENT_FD_READ,
kdc_socket_handler, kdc_socket);
status = socket_listen(kdc_socket->sock, address, port, 0, 0);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(0,("Failed to bind to %s:%d UDP - %s\n",
address, port, nt_errstr(status)));
talloc_free(kdc_socket);
return status;
}
/* within the kdc task we want to be a single process, so
ask for the single process model ops and pass these to the
stream_setup_socket() call. */
model_ops = process_model_byname("single");
if (!model_ops) {
DEBUG(0,("Can't find 'single' process model_ops\n"));
talloc_free(kdc_socket);
return NT_STATUS_INTERNAL_ERROR;
}
status = stream_setup_socket(kdc->task->event_ctx, model_ops, &kdc_tcp_stream_ops,
"ip", address, &port, kdc);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(0,("Failed to bind to %s:%u TCP - %s\n",
address, port, nt_errstr(status)));
talloc_free(kdc_socket);
return status;
}
return NT_STATUS_OK;
}
/*
setup our listening sockets on the configured network interfaces
*/
static NTSTATUS kdc_startup_interfaces(struct kdc_server *kdc)
{
int num_interfaces = iface_count();
TALLOC_CTX *tmp_ctx = talloc_new(kdc);
NTSTATUS status;
/* if we are allowing incoming packets from any address, then
we need to bind to the wildcard address */
if (!lp_bind_interfaces_only()) {
status = kdc_add_socket(kdc, "0.0.0.0");
NT_STATUS_NOT_OK_RETURN(status);
} else {
int i;
for (i=0; i<num_interfaces; i++) {
const char *address = talloc_strdup(tmp_ctx, iface_n_ip(i));
status = kdc_add_socket(kdc, address);
NT_STATUS_NOT_OK_RETURN(status);
}
}
talloc_free(tmp_ctx);
return NT_STATUS_OK;
}
/*
startup the kdc task
*/
static void kdc_task_init(struct task_server *task)
{
struct kdc_server *kdc;
NTSTATUS status;
krb5_error_code ret;
if (iface_count() == 0) {
task_server_terminate(task, "kdc: no network interfaces configured");
return;
}
kdc = talloc(task, struct kdc_server);
if (kdc == NULL) {
task_server_terminate(task, "kdc: out of memory");
return;
}
kdc->task = task;
/* Setup the KDC configuration */
kdc->config = talloc(kdc, krb5_kdc_configuration);
if (!kdc->config) {
task_server_terminate(task, "kdc: out of memory");
return;
}
krb5_kdc_default_config(kdc->config);
/* NAT and the like make this pointless, and painful */
kdc->config->check_ticket_addresses = FALSE;
initialize_krb5_error_table();
ret = smb_krb5_init_context(kdc, &kdc->smb_krb5_context);
if (ret) {
DEBUG(1,("kdc_task_init: krb5_init_context failed (%s)\n",
error_message(ret)));
task_server_terminate(task, "kdc: krb5_init_context failed");
return;
}
krb5_add_et_list(kdc->smb_krb5_context->krb5_context, initialize_hdb_error_table_r);
kdc->config->logf = kdc->smb_krb5_context->logf;
kdc->config->db = talloc(kdc->config, struct HDB *);
if (!kdc->config->db) {
task_server_terminate(task, "kdc: out of memory");
return;
}
kdc->config->num_db = 1;
ret = hdb_ldb_create(kdc, kdc->smb_krb5_context->krb5_context,
&kdc->config->db[0], lp_sam_url());
if (ret != 0) {
DEBUG(1, ("kdc_task_init: hdb_ldb_create fails: %s\n",
smb_get_krb5_error_message(kdc->smb_krb5_context->krb5_context, ret, kdc)));
task_server_terminate(task, "kdc: hdb_ldb_create failed");
return;
}
/* start listening on the configured network interfaces */
status = kdc_startup_interfaces(kdc);
if (!NT_STATUS_IS_OK(status)) {
task_server_terminate(task, "kdc failed to setup interfaces");
return;
}
irpc_add_name(task->msg_ctx, "kdc_server");
}
/*
called on startup of the KDC service
*/
static NTSTATUS kdc_init(struct event_context *event_ctx,
const struct model_ops *model_ops)
{
return task_server_startup(event_ctx, model_ops, kdc_task_init);
}
/* called at smbd startup - register ourselves as a server service */
NTSTATUS server_service_kdc_init(void)
{
return register_server_service("kdc", kdc_init);
}