/src/samba/source4/lib/messaging/messaging.c

Source
/*
   Unix SMB/CIFS implementation.

   Samba internal messaging functions

   Copyright (C) Andrew Tridgell 2004

   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 "lib/events/events.h"
#include "lib/util/server_id.h"
#include "system/filesys.h"
#include "messaging/messaging.h"
#include "messaging/messaging_internal.h"
#include "../lib/util/dlinklist.h"
#include "lib/socket/socket.h"
#include "librpc/gen_ndr/ndr_irpc.h"
#include "lib/messaging/irpc.h"
#include "../lib/util/unix_privs.h"
#include "librpc/rpc/dcerpc.h"
#include "cluster/cluster.h"
#include "../lib/util/tevent_ntstatus.h"
#include "lib/param/param.h"
#include "lib/util/server_id_db.h"
#include "lib/util/talloc_report_printf.h"
#include "lib/messaging/messages_dgm.h"
#include "lib/messaging/messages_dgm_ref.h"
#include "../source3/lib/messages_util.h"
#include <tdb.h>
#include "lib/util/idtree.h"

/* change the message version with any incompatible changes in the protocol */
#define IMESSAGING_VERSION 1

/*
  a pending irpc call
*/
struct irpc_request {
  struct irpc_request *prev, *next;
  struct imessaging_context *msg_ctx;
  int callid;
  struct {
    void (*handler)(struct irpc_request *irpc, struct irpc_message *m);
    void *private_data;
  } incoming;
};

/* we have a linked list of dispatch handlers for each msg_type that
   this messaging server can deal with */
struct dispatch_fn {
  struct dispatch_fn *next, *prev;
  uint32_t msg_type;
  void *private_data;
  msg_callback_t fn;
};

/* an individual message */

static void irpc_handler(struct imessaging_context *,
       void *,
       uint32_t,
       struct server_id,
       size_t,
       int *,
       DATA_BLOB *);


/*
 A useful function for testing the message system.
*/
static void ping_message(struct imessaging_context *msg,
       void *private_data,
       uint32_t msg_type,
       struct server_id src,
       size_t num_fds,
       int *fds,
       DATA_BLOB *data)
{
  struct server_id_buf idbuf;

  if (num_fds != 0) {
    DBG_WARNING("Received %zu fds, ignoring message\n", num_fds);
    return;
  }

  DEBUG(1,("INFO: Received PING message from server %s [%.*s]\n",
     server_id_str_buf(src, &idbuf), (int)data->length,
     data->data?(const char *)data->data:""));
  imessaging_send(msg, src, MSG_PONG, data);
}

static void pool_message(struct imessaging_context *msg,
       void *private_data,
       uint32_t msg_type,
       struct server_id src,
       size_t num_fds,
       int *fds,
       DATA_BLOB *data)
{
  FILE *f = NULL;

  if (num_fds != 1) {
    DBG_WARNING("Received %zu fds, ignoring message\n", num_fds);
    return;
  }

  f = fdopen(fds[0], "w");
  if (f == NULL) {
    DBG_DEBUG("fopen failed: %s\n", strerror(errno));
    return;
  }

  talloc_full_report_printf(NULL, f);
  fclose(f);
}

static void ringbuf_log_msg(struct imessaging_context *msg,
          void *private_data,
          uint32_t msg_type,
          struct server_id src,
          size_t num_fds,
          int *fds,
          DATA_BLOB *data)
{
  char *log = debug_get_ringbuf();
  size_t logsize = debug_get_ringbuf_size();
  DATA_BLOB blob;

  if (num_fds != 0) {
    DBG_WARNING("Received %zu fds, ignoring message\n", num_fds);
    return;
  }

  if (log == NULL) {
    log = discard_const_p(char, "*disabled*\n");
    logsize = strlen(log) + 1;
  }

  blob.data = (uint8_t *)log;
  blob.length = logsize;

  imessaging_send(msg, src, MSG_RINGBUF_LOG, &blob);
}

/****************************************************************************
 Receive a "set debug level" message.
****************************************************************************/

static void debug_imessage(struct imessaging_context *msg_ctx,
         void *private_data,
         uint32_t msg_type,
         struct server_id src,
         size_t num_fds,
         int *fds,
         DATA_BLOB *data)
{
  const char *params_str = (const char *)data->data;
  struct server_id_buf src_buf;
  struct server_id dst = imessaging_get_server_id(msg_ctx);
  struct server_id_buf dst_buf;

  if (num_fds != 0) {
    DBG_WARNING("Received %zu fds, ignoring message\n", num_fds);
    return;
  }

  /* Check, it's a proper string! */
  if (params_str[(data->length)-1] != '\0') {
    DBG_ERR("Invalid debug message from pid %s to pid %s\n",
      server_id_str_buf(src, &src_buf),
      server_id_str_buf(dst, &dst_buf));
    return;
  }

  DBG_ERR("INFO: Remote set of debug to `%s' (pid %s from pid %s)\n",
    params_str,
    server_id_str_buf(dst, &dst_buf),
    server_id_str_buf(src, &src_buf));

  debug_parse_levels(params_str);
}

/****************************************************************************
 Return current debug level.
****************************************************************************/

static void debuglevel_imessage(struct imessaging_context *msg_ctx,
        void *private_data,
        uint32_t msg_type,
        struct server_id src,
        size_t num_fds,
        int *fds,
        DATA_BLOB *data)
{
  char *message = debug_list_class_names_and_levels();
  DATA_BLOB blob = data_blob_null;
  struct server_id_buf src_buf;
  struct server_id dst = imessaging_get_server_id(msg_ctx);
  struct server_id_buf dst_buf;

  if (num_fds != 0) {
    DBG_WARNING("Received %zu fds, ignoring message\n", num_fds);
    return;
  }

  DBG_DEBUG("Received REQ_DEBUGLEVEL message (pid %s from pid %s)\n",
      server_id_str_buf(dst, &dst_buf),
      server_id_str_buf(src, &src_buf));

  if (message == NULL) {
    DBG_ERR("debug_list_class_names_and_levels returned NULL\n");
    return;
  }

  blob = data_blob_string_const_null(message);
  imessaging_send(msg_ctx, src, MSG_DEBUGLEVEL, &blob);

  TALLOC_FREE(message);
}

/*
  return uptime of messaging server via irpc
*/
static NTSTATUS irpc_uptime(struct irpc_message *msg,
          struct irpc_uptime *r)
{
  struct imessaging_context *ctx = talloc_get_type(msg->private_data, struct imessaging_context);
  *r->out.start_time = timeval_to_nttime(&ctx->start_time);
  return NT_STATUS_OK;
}

static struct dispatch_fn *imessaging_find_dispatch(
  struct imessaging_context *msg, uint32_t msg_type)
{
  /* temporary IDs use an idtree, the rest use a array of pointers */
  if (msg_type >= MSG_TMP_BASE) {
    return (struct dispatch_fn *)idr_find(msg->dispatch_tree,
                  msg_type);
  }
  if (msg_type < msg->num_types) {
    return msg->dispatch[msg_type];
  }
  return NULL;
}

/*
  Register a dispatch function for a particular message type.
*/
NTSTATUS imessaging_register(struct imessaging_context *msg, void *private_data,
          uint32_t msg_type, msg_callback_t fn)
{
  struct dispatch_fn *d;

  /* possibly expand dispatch array */
  if (msg_type >= msg->num_types) {
    struct dispatch_fn **dp;
    uint32_t i;
    dp = talloc_realloc(msg, msg->dispatch, struct dispatch_fn *, msg_type+1);
    NT_STATUS_HAVE_NO_MEMORY(dp);
    msg->dispatch = dp;
    for (i=msg->num_types;i<=msg_type;i++) {
      msg->dispatch[i] = NULL;
    }
    msg->num_types = msg_type+1;
  }

  d = talloc_zero(msg->dispatch, struct dispatch_fn);
  NT_STATUS_HAVE_NO_MEMORY(d);
  d->msg_type = msg_type;
  d->private_data = private_data;
  d->fn = fn;

  DLIST_ADD(msg->dispatch[msg_type], d);

  return NT_STATUS_OK;
}

/*
  register a temporary message handler. The msg_type is allocated
  above MSG_TMP_BASE
*/
NTSTATUS imessaging_register_tmp(struct imessaging_context *msg, void *private_data,
        msg_callback_t fn, uint32_t *msg_type)
{
  struct dispatch_fn *d;
  int id;

  d = talloc_zero(msg->dispatch, struct dispatch_fn);
  NT_STATUS_HAVE_NO_MEMORY(d);
  d->private_data = private_data;
  d->fn = fn;

  id = idr_get_new_above(msg->dispatch_tree, d, MSG_TMP_BASE, UINT16_MAX);
  if (id == -1) {
    talloc_free(d);
    return NT_STATUS_TOO_MANY_CONTEXT_IDS;
  }

  d->msg_type = (uint32_t)id;
  (*msg_type) = d->msg_type;

  return NT_STATUS_OK;
}

/*
  De-register the function for a particular message type. Return the number of
  functions deregistered.
*/
size_t imessaging_deregister(struct imessaging_context *msg, uint32_t msg_type, void *private_data)
{
  struct dispatch_fn *d, *next;
  size_t removed = 0;

  if (msg_type >= msg->num_types) {
    d = (struct dispatch_fn *)idr_find(msg->dispatch_tree,
               msg_type);
    if (!d) return 0;
    idr_remove(msg->dispatch_tree, msg_type);
    talloc_free(d);
    return 1;
  }

  for (d = msg->dispatch[msg_type]; d; d = next) {
    next = d->next;
    if (d->private_data == private_data) {
      DLIST_REMOVE(msg->dispatch[msg_type], d);
      talloc_free(d);
      ++removed;
    }
  }

  return removed;
}

/*
*/
int imessaging_cleanup(struct imessaging_context *msg)
{
  return 0;
}

static void imessaging_dgm_recv(struct tevent_context *ev,
        const uint8_t *buf, size_t buf_len,
        int *fds, size_t num_fds,
        void *private_data);

/* Keep a list of imessaging contexts */
static struct imessaging_context *msg_ctxs;

/*
 * A process has terminated, clean-up any names it has registered.
 */
NTSTATUS imessaging_process_cleanup(
  struct imessaging_context *msg_ctx,
  pid_t pid)
{
  struct irpc_name_records *names = NULL;
  uint32_t i = 0;
  uint32_t j = 0;
  TALLOC_CTX *mem_ctx = talloc_new(NULL);

  if (mem_ctx == NULL) {
    DBG_ERR("OOM unable to clean up messaging for process (%d)\n",
      pid);
    return NT_STATUS_NO_MEMORY;
  }

  names = irpc_all_servers(msg_ctx, mem_ctx);
  if (names == NULL) {
    TALLOC_FREE(mem_ctx);
    return NT_STATUS_OK;
  }
  for (i = 0; i < names->num_records; i++) {
    for (j = 0; j < names->names[i]->count; j++) {
      if (names->names[i]->ids[j].pid == pid) {
        int ret = server_id_db_prune_name(
          msg_ctx->names,
          names->names[i]->name,
          names->names[i]->ids[j]);
        if (ret != 0 && ret != ENOENT) {
          TALLOC_FREE(mem_ctx);
          return map_nt_error_from_unix_common(
              ret);
        }
      }
    }
  }
  TALLOC_FREE(mem_ctx);
  return NT_STATUS_OK;
}

static int imessaging_context_destructor(struct imessaging_context *msg)
{
  struct irpc_request *irpc = NULL;
  struct irpc_request *next = NULL;

  for (irpc = msg->requests; irpc != NULL; irpc = next) {
    next = irpc->next;

    DLIST_REMOVE(msg->requests, irpc);
    irpc->callid = -1;
  }

  DLIST_REMOVE(msg_ctxs, msg);
  TALLOC_FREE(msg->msg_dgm_ref);
  return 0;
}

/*
 * Cleanup messaging dgm contexts on a specific event context.
 *
 * We must make sure to unref all messaging_dgm_ref's *before* the
 * tevent context goes away. Only when the last ref is freed, the
 * refcounted messaging dgm context will be freed.
 */
void imessaging_dgm_unref_ev(struct tevent_context *ev)
{
  struct imessaging_context *msg = NULL;

  for (msg = msg_ctxs; msg != NULL; msg = msg->next) {
    if (msg->ev == ev) {
      TALLOC_FREE(msg->msg_dgm_ref);
    }
  }
}

static NTSTATUS imessaging_reinit(struct imessaging_context *msg)
{
  int ret = -1;
  struct irpc_request *irpc = NULL;
  struct irpc_request *next = NULL;

  for (irpc = msg->requests; irpc != NULL; irpc = next) {
    next = irpc->next;

    DLIST_REMOVE(msg->requests, irpc);
    irpc->callid = -1;
  }

  TALLOC_FREE(msg->msg_dgm_ref);

  if (msg->discard_incoming) {
    msg->num_incoming_listeners = 0;
  } else {
    msg->num_incoming_listeners = 1;
  }

  msg->server_id.pid = getpid();

  msg->msg_dgm_ref = messaging_dgm_ref(msg,
        msg->ev,
        &msg->server_id.unique_id,
        msg->sock_dir,
        msg->lock_dir,
        imessaging_dgm_recv,
        msg,
        &ret);

  if (msg->msg_dgm_ref == NULL) {
    DEBUG(2, ("messaging_dgm_ref failed: %s\n",
      strerror(ret)));
    return map_nt_error_from_unix_common(ret);
  }

  server_id_db_reinit(msg->names, msg->server_id);
  return NT_STATUS_OK;
}

/*
 * Must be called after a fork.
 */
NTSTATUS imessaging_reinit_all(void)
{
  struct imessaging_context *msg = NULL;

  for (msg = msg_ctxs; msg != NULL; msg = msg->next) {
    NTSTATUS status = imessaging_reinit(msg);
    if (!NT_STATUS_IS_OK(status)) {
      return status;
    }
  }
  return NT_STATUS_OK;
}

/*
  create the listening socket and setup the dispatcher
*/
static struct imessaging_context *imessaging_init_internal(
             TALLOC_CTX *mem_ctx,
             bool discard_incoming,
             struct loadparm_context *lp_ctx,
             struct server_id server_id,
             struct tevent_context *ev)
{
  NTSTATUS status;
  struct imessaging_context *msg;
  bool ok;
  int ret;
  const char *lock_dir = NULL;
  int tdb_flags = TDB_INCOMPATIBLE_HASH | TDB_CLEAR_IF_FIRST;

  if (ev == NULL) {
    return NULL;
  }

  msg = talloc_zero(mem_ctx, struct imessaging_context);
  if (msg == NULL) {
    return NULL;
  }
  msg->ev = ev;
  msg->discard_incoming = discard_incoming;
  if (msg->discard_incoming) {
    msg->num_incoming_listeners = 0;
  } else {
    msg->num_incoming_listeners = 1;
  }

  talloc_set_destructor(msg, imessaging_context_destructor);

  /* create the messaging directory if needed */

  lock_dir = lpcfg_lock_directory(lp_ctx);
  if (lock_dir == NULL) {
    goto fail;
  }

  msg->sock_dir = lpcfg_private_path(msg, lp_ctx, "msg.sock");
  if (msg->sock_dir == NULL) {
    goto fail;
  }
  ok = directory_create_or_exist_strict(msg->sock_dir, geteuid(), 0700);
  if (!ok) {
    goto fail;
  }

  msg->lock_dir = lpcfg_lock_path(msg, lp_ctx, "msg.lock");
  if (msg->lock_dir == NULL) {
    goto fail;
  }
  ok = directory_create_or_exist_strict(msg->lock_dir, geteuid(), 0755);
  if (!ok) {
    goto fail;
  }

  msg->msg_dgm_ref = messaging_dgm_ref(
    msg, ev, &server_id.unique_id, msg->sock_dir, msg->lock_dir,
    imessaging_dgm_recv, msg, &ret);

  if (msg->msg_dgm_ref == NULL) {
    goto fail;
  }

  msg->server_id     = server_id;
  msg->idr           = idr_init(msg);
  if (msg->idr == NULL) {
    goto fail;
  }

  msg->dispatch_tree = idr_init(msg);
  if (msg->dispatch_tree == NULL) {
    goto fail;
  }

  msg->start_time    = timeval_current();

  tdb_flags |= lpcfg_tdb_flags(lp_ctx, 0);

  /*
   * This context holds a destructor that cleans up any names
   * registered on this context on talloc_free()
   */
  msg->names = server_id_db_init(msg, server_id, lock_dir, 0, tdb_flags);
  if (msg->names == NULL) {
    goto fail;
  }

  status = imessaging_register(msg, NULL, MSG_PING, ping_message);
  if (!NT_STATUS_IS_OK(status)) {
    goto fail;
  }
  status = imessaging_register(msg, NULL, MSG_REQ_POOL_USAGE,
             pool_message);
  if (!NT_STATUS_IS_OK(status)) {
    goto fail;
  }
  status = imessaging_register(msg, NULL, MSG_IRPC, irpc_handler);
  if (!NT_STATUS_IS_OK(status)) {
    goto fail;
  }
  status = imessaging_register(msg, NULL, MSG_REQ_RINGBUF_LOG,
             ringbuf_log_msg);
  if (!NT_STATUS_IS_OK(status)) {
    goto fail;
  }
  status = imessaging_register(msg, NULL, MSG_DEBUG,
             debug_imessage);
  if (!NT_STATUS_IS_OK(status)) {
    goto fail;
  }
  status = imessaging_register(msg, NULL, MSG_REQ_DEBUGLEVEL,
             debuglevel_imessage);
  if (!NT_STATUS_IS_OK(status)) {
    goto fail;
  }
  status = IRPC_REGISTER(msg, irpc, IRPC_UPTIME, irpc_uptime, msg);
  if (!NT_STATUS_IS_OK(status)) {
    goto fail;
  }
#if defined(DEVELOPER) || defined(ENABLE_SELFTEST)
  /*
   * Register handlers for messages specific to developer and
   * self test builds
   */
  status = imessaging_register_extra_handlers(msg);
  if (!NT_STATUS_IS_OK(status)) {
    goto fail;
  }
#endif /* defined(DEVELOPER) || defined(ENABLE_SELFTEST) */

  DLIST_ADD(msg_ctxs, msg);

  return msg;
fail:
  talloc_free(msg);
  return NULL;
}

/*
  create the listening socket and setup the dispatcher
*/
struct imessaging_context *imessaging_init(TALLOC_CTX *mem_ctx,
             struct loadparm_context *lp_ctx,
             struct server_id server_id,
             struct tevent_context *ev)
{
  bool discard_incoming = false;
  return imessaging_init_internal(mem_ctx,
          discard_incoming,
          lp_ctx,
          server_id,
          ev);
}

struct imessaging_context *imessaging_init_discard_incoming(
            TALLOC_CTX *mem_ctx,
            struct loadparm_context *lp_ctx,
            struct server_id server_id,
            struct tevent_context *ev)
{
  bool discard_incoming = true;
  return imessaging_init_internal(mem_ctx,
          discard_incoming,
          lp_ctx,
          server_id,
          ev);
}

struct imessaging_post_state {
  struct imessaging_context *msg_ctx;
  struct imessaging_post_state **busy_ref;
  size_t buf_len;
  uint8_t buf[];
};

static int imessaging_post_state_destructor(struct imessaging_post_state *state)
{
  if (state->busy_ref != NULL) {
    *state->busy_ref = NULL;
    state->busy_ref = NULL;
  }
  return 0;
}

static void imessaging_post_handler(struct tevent_context *ev,
            struct tevent_immediate *ti,
            void *private_data)
{
  struct imessaging_post_state *state = talloc_get_type_abort(
    private_data, struct imessaging_post_state);

  if (state == NULL) {
    return;
  }

  /*
   * In usecases like using messaging_client_init() with irpc processing
   * we may free the imessaging_context during the messaging handler.
   * imessaging_post_state is a child of imessaging_context and
   * might be implicitly free'ed before the explicit TALLOC_FREE(state).
   *
   * The busy_ref pointer makes sure the destructor clears
   * the local 'state' variable.
   */

  SMB_ASSERT(state->busy_ref == NULL);
  state->busy_ref = &state;

  imessaging_dgm_recv(ev, state->buf, state->buf_len, NULL, 0,
          state->msg_ctx);

  state->busy_ref = NULL;
  TALLOC_FREE(state);
}

static int imessaging_post_self(struct imessaging_context *msg,
        const uint8_t *buf, size_t buf_len)
{
  struct tevent_immediate *ti;
  struct imessaging_post_state *state;

  state = talloc_size(
    msg, offsetof(struct imessaging_post_state, buf) + buf_len);
  if (state == NULL) {
    return ENOMEM;
  }
  talloc_set_name_const(state, "struct imessaging_post_state");

  talloc_set_destructor(state, imessaging_post_state_destructor);

  ti = tevent_create_immediate(state);
  if (ti == NULL) {
    TALLOC_FREE(state);
    return ENOMEM;
  }

  state->msg_ctx = msg;
  state->busy_ref = NULL;
  state->buf_len = buf_len;
  memcpy(state->buf, buf, buf_len);

  tevent_schedule_immediate(ti, msg->ev, imessaging_post_handler,
          state);

  return 0;
}

static void imessaging_dgm_recv(struct tevent_context *ev,
        const uint8_t *buf, size_t buf_len,
        int *fds, size_t num_fds,
        void *private_data)
{
  struct imessaging_context *msg = talloc_get_type_abort(
    private_data, struct imessaging_context);
  uint32_t msg_type;
  struct server_id src, dst;
  struct server_id_buf srcbuf, dstbuf;
  DATA_BLOB data;

  if (buf_len < MESSAGE_HDR_LENGTH) {
    /* Invalid message, ignore */
    return;
  }

  if (msg->num_incoming_listeners == 0) {
    struct server_id_buf selfbuf;

    message_hdr_get(&msg_type, &src, &dst, buf);

    DBG_DEBUG("not listening - discarding message from "
        "src[%s] to dst[%s] (self[%s]) type=0x%x "
        "on %s event context\n",
         server_id_str_buf(src, &srcbuf),
         server_id_str_buf(dst, &dstbuf),
         server_id_str_buf(msg->server_id, &selfbuf),
         (unsigned)msg_type,
         (ev != msg->ev) ? "different" : "main");
    return;
  }

  if (ev != msg->ev) {
    int ret;
    ret = imessaging_post_self(msg, buf, buf_len);
    if (ret != 0) {
      DBG_WARNING("imessaging_post_self failed: %s\n",
            strerror(ret));
    }
    return;
  }

  message_hdr_get(&msg_type, &src, &dst, buf);

  data.data = discard_const_p(uint8_t, buf + MESSAGE_HDR_LENGTH);
  data.length = buf_len - MESSAGE_HDR_LENGTH;

  if ((cluster_id_equal(&dst, &msg->server_id)) ||
      ((dst.task_id == 0) && (msg->server_id.pid == 0))) {
    struct dispatch_fn *d, *next;

    DEBUG(10, ("%s: dst %s matches my id: %s, type=0x%x\n",
         __func__,
         server_id_str_buf(dst, &dstbuf),
         server_id_str_buf(msg->server_id, &srcbuf),
         (unsigned)msg_type));

    d = imessaging_find_dispatch(msg, msg_type);

    for (; d; d = next) {
      next = d->next;
      d->fn(msg,
            d->private_data,
            d->msg_type,
            src,
            num_fds,
            fds,
            &data);
    }
  } else {
    DEBUG(10, ("%s: Ignoring type=0x%x dst %s, I am %s, \n",
         __func__, (unsigned)msg_type,
         server_id_str_buf(dst, &dstbuf),
         server_id_str_buf(msg->server_id, &srcbuf)));
  }
}

/*
   A hack, for the short term until we get 'client only' messaging in place
*/
struct imessaging_context *imessaging_client_init(TALLOC_CTX *mem_ctx,
              struct loadparm_context *lp_ctx,
            struct tevent_context *ev)
{
  struct server_id id = {
    .pid = getpid(),
    .task_id = generate_random(),
    .vnn = NONCLUSTER_VNN,

    /* This is because we are not in the s3 serverid database */
    .unique_id = SERVERID_UNIQUE_ID_NOT_TO_VERIFY,
  };

  return imessaging_init_discard_incoming(mem_ctx, lp_ctx, id, ev);
}

/*
  a list of registered irpc server functions
*/
struct irpc_list {
  struct irpc_list *next, *prev;
  struct GUID uuid;
  const struct ndr_interface_table *table;
  int callnum;
  irpc_function_t fn;
  void *private_data;
};


/*
  register a irpc server function
*/
NTSTATUS irpc_register(struct imessaging_context *msg_ctx,
           const struct ndr_interface_table *table,
           int callnum, irpc_function_t fn, void *private_data)
{
  struct irpc_list *irpc;

  /* override an existing handler, if any */
  for (irpc=msg_ctx->irpc; irpc; irpc=irpc->next) {
    if (irpc->table == table && irpc->callnum == callnum) {
      break;
    }
  }
  if (irpc == NULL) {
    irpc = talloc(msg_ctx, struct irpc_list);
    NT_STATUS_HAVE_NO_MEMORY(irpc);
    DLIST_ADD(msg_ctx->irpc, irpc);
  }

  irpc->table   = table;
  irpc->callnum = callnum;
  irpc->fn      = fn;
  irpc->private_data = private_data;
  irpc->uuid = irpc->table->syntax_id.uuid;

  return NT_STATUS_OK;
}


/*
  handle an incoming irpc reply message
*/
static void irpc_handler_reply(struct imessaging_context *msg_ctx, struct irpc_message *m)
{
  struct irpc_request *irpc;

  irpc = (struct irpc_request *)idr_find(msg_ctx->idr, m->header.callid);
  if (irpc == NULL) return;

  irpc->incoming.handler(irpc, m);
}

/*
  send a irpc reply
*/
NTSTATUS irpc_send_reply(struct irpc_message *m, NTSTATUS status)
{
  struct ndr_push *push;
  DATA_BLOB packet;
  enum ndr_err_code ndr_err;

  m->header.status = status;

  /* setup the reply */
  push = ndr_push_init_ctx(m->ndr);
  if (push == NULL) {
    status = NT_STATUS_NO_MEMORY;
    goto failed;
  }

  m->header.flags |= IRPC_FLAG_REPLY;
  m->header.creds.token= NULL;

  /* construct the packet */
  ndr_err = ndr_push_irpc_header(push, NDR_SCALARS|NDR_BUFFERS, &m->header);
  if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
    status = ndr_map_error2ntstatus(ndr_err);
    goto failed;
  }

  ndr_err = m->irpc->table->calls[m->irpc->callnum].ndr_push(push, NDR_OUT, m->data);
  if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
    status = ndr_map_error2ntstatus(ndr_err);
    goto failed;
  }

  /* send the reply message */
  packet = ndr_push_blob(push);
  status = imessaging_send(m->msg_ctx, m->from, MSG_IRPC, &packet);
  if (!NT_STATUS_IS_OK(status)) goto failed;

failed:
  talloc_free(m);
  return status;
}

/*
  handle an incoming irpc request message
*/
static void irpc_handler_request(struct imessaging_context *msg_ctx,
         struct irpc_message *m)
{
  struct irpc_list *i;
  void *r;
  enum ndr_err_code ndr_err;

  for (i=msg_ctx->irpc; i; i=i->next) {
    if (GUID_equal(&i->uuid, &m->header.uuid) &&
        i->table->syntax_id.if_version == m->header.if_version &&
        i->callnum == m->header.callnum) {
      break;
    }
  }

  if (i == NULL) {
    /* no registered handler for this message */
    talloc_free(m);
    return;
  }

  /* allocate space for the structure */
  r = talloc_zero_size(m->ndr, i->table->calls[m->header.callnum].struct_size);
  if (r == NULL) goto failed;

  m->ndr->flags |= LIBNDR_FLAG_REF_ALLOC;

  /* parse the request data */
  ndr_err = i->table->calls[i->callnum].ndr_pull(m->ndr, NDR_IN, r);
  if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) goto failed;

  /* make the call */
  m->private_data= i->private_data;
  m->defer_reply = false;
  m->no_reply    = false;
  m->msg_ctx     = msg_ctx;
  m->irpc        = i;
  m->data        = r;

  m->header.status = i->fn(m, r);

  if (m->no_reply) {
    /* the server function won't ever be replying to this request */
    talloc_free(m);
    return;
  }

  if (m->defer_reply) {
    /* the server function has asked to defer the reply to later */
    talloc_steal(msg_ctx, m);
    return;
  }

  irpc_send_reply(m, m->header.status);
  return;

failed:
  talloc_free(m);
}

/*
  handle an incoming irpc message
*/
static void irpc_handler(struct imessaging_context *msg_ctx,
       void *private_data,
       uint32_t msg_type,
       struct server_id src,
       size_t num_fds,
       int *fds,
       DATA_BLOB *packet)
{
  struct irpc_message *m;
  enum ndr_err_code ndr_err;

  if (num_fds != 0) {
    DBG_WARNING("Received %zu fds, ignoring message\n", num_fds);
    return;
  }

  m = talloc(msg_ctx, struct irpc_message);
  if (m == NULL) goto failed;

  m->from = src;

  m->ndr = ndr_pull_init_blob(packet, m);
  if (m->ndr == NULL) goto failed;

  m->ndr->flags |= LIBNDR_FLAG_REF_ALLOC;

  ndr_err = ndr_pull_irpc_header(m->ndr, NDR_BUFFERS|NDR_SCALARS, &m->header);
  if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) goto failed;

  if (m->header.flags & IRPC_FLAG_REPLY) {
    irpc_handler_reply(msg_ctx, m);
  } else {
    irpc_handler_request(msg_ctx, m);
  }
  return;

failed:
  talloc_free(m);
}


/*
  destroy a irpc request
*/
static int irpc_destructor(struct irpc_request *irpc)
{
  if (irpc->callid != -1) {
    DLIST_REMOVE(irpc->msg_ctx->requests, irpc);
    idr_remove(irpc->msg_ctx->idr, irpc->callid);
    if (irpc->msg_ctx->discard_incoming) {
      SMB_ASSERT(irpc->msg_ctx->num_incoming_listeners > 0);
    } else {
      SMB_ASSERT(irpc->msg_ctx->num_incoming_listeners > 1);
    }
    irpc->msg_ctx->num_incoming_listeners -= 1;
    irpc->callid = -1;
  }

  return 0;
}

/*
  add a string name that this irpc server can be called on

  It will be removed from the DB either via irpc_remove_name or on
  talloc_free(msg_ctx->names).
*/
NTSTATUS irpc_add_name(struct imessaging_context *msg_ctx, const char *name)
{
  int ret;

  ret = server_id_db_add(msg_ctx->names, name);
  if (ret != 0) {
    return map_nt_error_from_unix_common(ret);
  }
  return NT_STATUS_OK;
}

static int all_servers_func(const char *name, unsigned num_servers,
          const struct server_id *servers,
          void *private_data)
{
  struct irpc_name_records *name_records = talloc_get_type(
    private_data, struct irpc_name_records);
  struct irpc_name_record *name_record;
  uint32_t i;

  name_records->names
    = talloc_realloc(name_records, name_records->names,
         struct irpc_name_record *, name_records->num_records+1);
  if (!name_records->names) {
    return -1;
  }

  name_records->names[name_records->num_records] = name_record
    = talloc(name_records->names,
       struct irpc_name_record);
  if (!name_record) {
    return -1;
  }

  name_records->num_records++;

  name_record->name = talloc_strdup(name_record, name);
  if (!name_record->name) {
    return -1;
  }

  name_record->count = num_servers;
  name_record->ids = talloc_array(name_record, struct server_id,
          num_servers);
  if (name_record->ids == NULL) {
    return -1;
  }
  for (i=0;i<name_record->count;i++) {
    name_record->ids[i] = servers[i];
  }
  return 0;
}

/*
  return a list of server ids for a server name
*/
struct irpc_name_records *irpc_all_servers(struct imessaging_context *msg_ctx,
             TALLOC_CTX *mem_ctx)
{
  int ret;
  struct irpc_name_records *name_records = talloc_zero(mem_ctx, struct irpc_name_records);
  if (name_records == NULL) {
    return NULL;
  }

  ret = server_id_db_traverse_read(msg_ctx->names, all_servers_func,
           name_records);
  if (ret == -1) {
    TALLOC_FREE(name_records);
    return NULL;
  }

  return name_records;
}

/*
  remove a name from a messaging context
*/
void irpc_remove_name(struct imessaging_context *msg_ctx, const char *name)
{
  server_id_db_remove(msg_ctx->names, name);
}

struct server_id imessaging_get_server_id(struct imessaging_context *msg_ctx)
{
  return msg_ctx->server_id;
}

struct irpc_bh_state {
  struct imessaging_context *msg_ctx;
  const struct dcerpc_binding *binding;
  struct server_id server_id;
  const struct ndr_interface_table *table;
  uint32_t timeout;
  struct security_token *token;
};

static const struct dcerpc_binding *irpc_bh_get_binding(struct dcerpc_binding_handle *h)
{
  struct irpc_bh_state *hs = dcerpc_binding_handle_data(h,
           struct irpc_bh_state);

  return hs->binding;
}

static bool irpc_bh_is_connected(struct dcerpc_binding_handle *h)
{
  struct irpc_bh_state *hs = dcerpc_binding_handle_data(h,
           struct irpc_bh_state);

  if (!hs->msg_ctx) {
    return false;
  }

  return true;
}

static uint32_t irpc_bh_set_timeout(struct dcerpc_binding_handle *h,
            uint32_t timeout)
{
  struct irpc_bh_state *hs = dcerpc_binding_handle_data(h,
           struct irpc_bh_state);
  uint32_t old = hs->timeout;

  hs->timeout = timeout;

  return old;
}

struct irpc_bh_raw_call_state {
  struct irpc_request *irpc;
  uint32_t opnum;
  DATA_BLOB in_data;
  DATA_BLOB in_packet;
  DATA_BLOB out_data;
};

static void irpc_bh_raw_call_incoming_handler(struct irpc_request *irpc,
                struct irpc_message *m);

static struct tevent_req *irpc_bh_raw_call_send(TALLOC_CTX *mem_ctx,
            struct tevent_context *ev,
            struct dcerpc_binding_handle *h,
            const struct GUID *object,
            uint32_t opnum,
            uint32_t in_flags,
            const uint8_t *in_data,
            size_t in_length)
{
  struct irpc_bh_state *hs =
    dcerpc_binding_handle_data(h,
    struct irpc_bh_state);
  struct tevent_req *req;
  struct irpc_bh_raw_call_state *state;
  bool ok;
  struct irpc_header header;
  struct ndr_push *ndr;
  NTSTATUS status;
  enum ndr_err_code ndr_err;

  req = tevent_req_create(mem_ctx, &state,
        struct irpc_bh_raw_call_state);
  if (req == NULL) {
    return NULL;
  }
  state->opnum = opnum;
  state->in_data.data = discard_const_p(uint8_t, in_data);
  state->in_data.length = in_length;

  ok = irpc_bh_is_connected(h);
  if (!ok) {
    tevent_req_nterror(req, NT_STATUS_CONNECTION_DISCONNECTED);
    return tevent_req_post(req, ev);
  }

  state->irpc = talloc_zero(state, struct irpc_request);
  if (tevent_req_nomem(state->irpc, req)) {
    return tevent_req_post(req, ev);
  }

  state->irpc->msg_ctx  = hs->msg_ctx;
  state->irpc->callid   = idr_get_new(hs->msg_ctx->idr,
              state->irpc, UINT16_MAX);
  if (state->irpc->callid == -1) {
    tevent_req_nterror(req, NT_STATUS_INSUFFICIENT_RESOURCES);
    return tevent_req_post(req, ev);
  }
  state->irpc->incoming.handler = irpc_bh_raw_call_incoming_handler;
  state->irpc->incoming.private_data = req;

  /* make sure we accept incoming messages */
  SMB_ASSERT(state->irpc->msg_ctx->num_incoming_listeners < UINT64_MAX);
  state->irpc->msg_ctx->num_incoming_listeners += 1;
  DLIST_ADD_END(state->irpc->msg_ctx->requests, state->irpc);
  talloc_set_destructor(state->irpc, irpc_destructor);

  /* setup the header */
  header.uuid = hs->table->syntax_id.uuid;

  header.if_version = hs->table->syntax_id.if_version;
  header.callid     = state->irpc->callid;
  header.callnum    = state->opnum;
  header.flags      = 0;
  header.status     = NT_STATUS_OK;
  header.creds.token= hs->token;

  /* construct the irpc packet */
  ndr = ndr_push_init_ctx(state->irpc);
  if (tevent_req_nomem(ndr, req)) {
    return tevent_req_post(req, ev);
  }

  ndr_err = ndr_push_irpc_header(ndr, NDR_SCALARS|NDR_BUFFERS, &header);
  status = ndr_map_error2ntstatus(ndr_err);
  if (!NT_STATUS_IS_OK(status)) {
    tevent_req_nterror(req, status);
    return tevent_req_post(req, ev);
  }

  ndr_err = ndr_push_bytes(ndr, in_data, in_length);
  status = ndr_map_error2ntstatus(ndr_err);
  if (!NT_STATUS_IS_OK(status)) {
    tevent_req_nterror(req, status);
    return tevent_req_post(req, ev);
  }

  /* and send it */
  state->in_packet = ndr_push_blob(ndr);
  status = imessaging_send(hs->msg_ctx, hs->server_id,
        MSG_IRPC, &state->in_packet);
  if (!NT_STATUS_IS_OK(status)) {
    tevent_req_nterror(req, status);
    return tevent_req_post(req, ev);
  }

  if (hs->timeout != IRPC_CALL_TIMEOUT_INF) {
    /* set timeout-callback in case caller wants that */
    ok = tevent_req_set_endtime(req, ev, timeval_current_ofs(hs->timeout, 0));
    if (!ok) {
      return tevent_req_post(req, ev);
    }
  }

  return req;
}

static void irpc_bh_raw_call_incoming_handler(struct irpc_request *irpc,
                struct irpc_message *m)
{
  struct tevent_req *req =
    talloc_get_type_abort(irpc->incoming.private_data,
    struct tevent_req);
  struct irpc_bh_raw_call_state *state =
    tevent_req_data(req,
    struct irpc_bh_raw_call_state);

  talloc_steal(state, m);

  if (!NT_STATUS_IS_OK(m->header.status)) {
    tevent_req_nterror(req, m->header.status);
    return;
  }

  state->out_data = data_blob_talloc(state,
    m->ndr->data + m->ndr->offset,
    m->ndr->data_size - m->ndr->offset);
  if ((m->ndr->data_size - m->ndr->offset) > 0 && !state->out_data.data) {
    tevent_req_oom(req);
    return;
  }

  tevent_req_done(req);
}

static NTSTATUS irpc_bh_raw_call_recv(struct tevent_req *req,
          TALLOC_CTX *mem_ctx,
          uint8_t **out_data,
          size_t *out_length,
          uint32_t *out_flags)
{
  struct irpc_bh_raw_call_state *state =
    tevent_req_data(req,
    struct irpc_bh_raw_call_state);
  NTSTATUS status;

  if (tevent_req_is_nterror(req, &status)) {
    tevent_req_received(req);
    return status;
  }

  *out_data = talloc_move(mem_ctx, &state->out_data.data);
  *out_length = state->out_data.length;
  *out_flags = 0;
  tevent_req_received(req);
  return NT_STATUS_OK;
}

struct irpc_bh_disconnect_state {
  uint8_t _dummy;
};

static struct tevent_req *irpc_bh_disconnect_send(TALLOC_CTX *mem_ctx,
            struct tevent_context *ev,
            struct dcerpc_binding_handle *h)
{
  struct irpc_bh_state *hs = dcerpc_binding_handle_data(h,
             struct irpc_bh_state);
  struct tevent_req *req;
  struct irpc_bh_disconnect_state *state;
  bool ok;

  req = tevent_req_create(mem_ctx, &state,
        struct irpc_bh_disconnect_state);
  if (req == NULL) {
    return NULL;
  }

  ok = irpc_bh_is_connected(h);
  if (!ok) {
    tevent_req_nterror(req, NT_STATUS_CONNECTION_DISCONNECTED);
    return tevent_req_post(req, ev);
  }

  hs->msg_ctx = NULL;

  tevent_req_done(req);
  return tevent_req_post(req, ev);
}

static NTSTATUS irpc_bh_disconnect_recv(struct tevent_req *req)
{
  NTSTATUS status;

  if (tevent_req_is_nterror(req, &status)) {
    tevent_req_received(req);
    return status;
  }

  tevent_req_received(req);
  return NT_STATUS_OK;
}

static bool irpc_bh_ref_alloc(struct dcerpc_binding_handle *h)
{
  return true;
}

static void irpc_bh_do_ndr_print(struct dcerpc_binding_handle *h,
         ndr_flags_type ndr_flags,
         const void *_struct_ptr,
         const struct ndr_interface_call *call)
{
  void *struct_ptr = discard_const(_struct_ptr);
  bool print_in = false;
  bool print_out = false;

  if (CHECK_DEBUGLVLC(DBGC_RPC_PARSE, 11)) {
    print_in = true;
    print_out = true;
  }

  if (ndr_flags & NDR_IN) {
    if (print_in) {
      ndr_print_function_debug(call->ndr_print,
             call->name,
             ndr_flags,
             struct_ptr);
    }
  }
  if (ndr_flags & NDR_OUT) {
    if (print_out) {
      ndr_print_function_debug(call->ndr_print,
             call->name,
             ndr_flags,
             struct_ptr);
    }
  }
}

static const struct dcerpc_binding_handle_ops irpc_bh_ops = {
  .name     = "wbint",
  .get_binding    = irpc_bh_get_binding,
  .is_connected   = irpc_bh_is_connected,
  .set_timeout    = irpc_bh_set_timeout,
  .raw_call_send    = irpc_bh_raw_call_send,
  .raw_call_recv    = irpc_bh_raw_call_recv,
  .disconnect_send  = irpc_bh_disconnect_send,
  .disconnect_recv  = irpc_bh_disconnect_recv,

  .ref_alloc    = irpc_bh_ref_alloc,
  .do_ndr_print   = irpc_bh_do_ndr_print,
};

/* initialise a irpc binding handle */
struct dcerpc_binding_handle *irpc_binding_handle(TALLOC_CTX *mem_ctx,
              struct imessaging_context *msg_ctx,
              struct server_id server_id,
              const struct ndr_interface_table *table)
{
  struct dcerpc_binding_handle *h = NULL;
  struct irpc_bh_state *hs = NULL;
  struct dcerpc_binding *b = NULL;
  NTSTATUS status;

  h = dcerpc_binding_handle_create(mem_ctx,
           &irpc_bh_ops,
           NULL,
           table,
           &hs,
           struct irpc_bh_state,
           __location__);
  if (h == NULL) {
    return NULL;
  }
  hs->msg_ctx = msg_ctx;
  hs->server_id = server_id;
  hs->table = table;
  hs->timeout = IRPC_CALL_TIMEOUT;

  status = dcerpc_parse_binding(hs, "", &b);
  if (!NT_STATUS_IS_OK(status)) {
    TALLOC_FREE(h);
    return NULL;
  }
  status = dcerpc_binding_set_transport(b, NCACN_INTERNAL);
  if (!NT_STATUS_IS_OK(status)) {
    TALLOC_FREE(h);
    return NULL;
  }
  status = dcerpc_binding_set_string_option(b, "host", "localhost");
  if (!NT_STATUS_IS_OK(status)) {
    TALLOC_FREE(h);
    return NULL;
  }
  status = dcerpc_binding_set_string_option(b, "endpoint", "irpc");
  if (!NT_STATUS_IS_OK(status)) {
    TALLOC_FREE(h);
    return NULL;
  }
  status = dcerpc_binding_set_abstract_syntax(b, &table->syntax_id);
  if (!NT_STATUS_IS_OK(status)) {
    TALLOC_FREE(h);
    return NULL;
  }

  hs->binding = b;

  return h;
}

struct dcerpc_binding_handle *irpc_binding_handle_by_name(TALLOC_CTX *mem_ctx,
                struct imessaging_context *msg_ctx,
                const char *dest_task,
                const struct ndr_interface_table *table)
{
  struct dcerpc_binding_handle *h;
  unsigned num_sids;
  struct server_id *sids;
  struct server_id sid;
  NTSTATUS status;

  /* find the server task */

  status = irpc_servers_byname(msg_ctx, mem_ctx, dest_task,
             &num_sids, &sids);
  if (!NT_STATUS_IS_OK(status)) {
    errno = EADDRNOTAVAIL;
    return NULL;
  }
  sid = sids[0];
  talloc_free(sids);

  h = irpc_binding_handle(mem_ctx, msg_ctx,
        sid, table);
  if (h == NULL) {
    return NULL;
  }

  return h;
}

void irpc_binding_handle_add_security_token(struct dcerpc_binding_handle *h,
              struct security_token *token)
{
  struct irpc_bh_state *hs =
    dcerpc_binding_handle_data(h,
    struct irpc_bh_state);

  hs->token = token;
}

Coverage Report

Created: 2026-09-03 07:24