source: branches/samba-3.5.x/source4/librpc/rpc/dcerpc_sock.c

/* 
   Unix SMB/CIFS implementation.

   dcerpc over standard sockets transport

   Copyright (C) Andrew Tridgell 2003
   Copyright (C) Jelmer Vernooij 2004
   Copyright (C) Rafal Szczesniak 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"
#include "lib/events/events.h"
#include "lib/socket/socket.h"
#include "lib/stream/packet.h"
#include "libcli/composite/composite.h"
#include "librpc/rpc/dcerpc.h"
#include "librpc/rpc/dcerpc_proto.h"
#include "libcli/resolve/resolve.h"

/* transport private information used by general socket pipe transports */
struct sock_private {
        struct tevent_fd *fde;
        struct socket_context *sock;
        char *server_name;

        struct packet_context *packet;
        uint32_t pending_reads;

        const char *path; /* For ncacn_unix_sock and ncalrpc */
};


/*
  mark the socket dead
*/
static void sock_dead(struct dcerpc_connection *p, NTSTATUS status)
{
        struct sock_private *sock = (struct sock_private *)p->transport.private_data;

        if (!sock) return;

        if (sock->packet) {
                packet_recv_disable(sock->packet);
                packet_set_fde(sock->packet, NULL);
                packet_set_socket(sock->packet, NULL);
        }

        if (sock->fde) {
                talloc_free(sock->fde);
                sock->fde = NULL;
        }

        if (sock->sock) {
                talloc_free(sock->sock);
                sock->sock = NULL;
        }

        if (NT_STATUS_EQUAL(NT_STATUS_UNSUCCESSFUL, status)) {
                status = NT_STATUS_UNEXPECTED_NETWORK_ERROR;
        }

        if (NT_STATUS_EQUAL(NT_STATUS_OK, status)) {
                status = NT_STATUS_END_OF_FILE;
        }

        if (p->transport.recv_data) {
                p->transport.recv_data(p, NULL, status);
        }
}


/*
  handle socket recv errors
*/
static void sock_error_handler(void *private_data, NTSTATUS status)
{
        struct dcerpc_connection *p = talloc_get_type(private_data,
                                                      struct dcerpc_connection);
        sock_dead(p, status);
}

/*
  check if a blob is a complete packet
*/
static NTSTATUS sock_complete_packet(void *private_data, DATA_BLOB blob, size_t *size)
{
        if (blob.length < DCERPC_FRAG_LEN_OFFSET+2) {
                return STATUS_MORE_ENTRIES;
        }
        *size = dcerpc_get_frag_length(&blob);
        if (*size > blob.length) {
                return STATUS_MORE_ENTRIES;
        }
        return NT_STATUS_OK;
}

/*
  process recv requests
*/
static NTSTATUS sock_process_recv(void *private_data, DATA_BLOB blob)
{
        struct dcerpc_connection *p = talloc_get_type(private_data,
                                                      struct dcerpc_connection);
        struct sock_private *sock = (struct sock_private *)p->transport.private_data;
        sock->pending_reads--;
        if (sock->pending_reads == 0) {
                packet_recv_disable(sock->packet);
        }
        p->transport.recv_data(p, &blob, NT_STATUS_OK);
        return NT_STATUS_OK;
}

/*
  called when a IO is triggered by the events system
*/
static void sock_io_handler(struct tevent_context *ev, struct tevent_fd *fde, 
                            uint16_t flags, void *private_data)
{
        struct dcerpc_connection *p = talloc_get_type(private_data,
                                                      struct dcerpc_connection);
        struct sock_private *sock = (struct sock_private *)p->transport.private_data;

        if (flags & EVENT_FD_WRITE) {
                packet_queue_run(sock->packet);
                return;
        }

        if (sock->sock == NULL) {
                return;
        }

        if (flags & EVENT_FD_READ) {
                packet_recv(sock->packet);
        }
}

/* 
   initiate a read request - not needed for dcerpc sockets
*/
static NTSTATUS sock_send_read(struct dcerpc_connection *p)
{
        struct sock_private *sock = (struct sock_private *)p->transport.private_data;
        sock->pending_reads++;
        if (sock->pending_reads == 1) {
                packet_recv_enable(sock->packet);
        }
        return NT_STATUS_OK;
}

/* 
   send an initial pdu in a multi-pdu sequence
*/
static NTSTATUS sock_send_request(struct dcerpc_connection *p, DATA_BLOB *data, 
                                  bool trigger_read)
{
        struct sock_private *sock = (struct sock_private *)p->transport.private_data;
        DATA_BLOB blob;
        NTSTATUS status;

        if (sock->sock == NULL) {
                return NT_STATUS_CONNECTION_DISCONNECTED;
        }

        blob = data_blob_talloc(sock->packet, data->data, data->length);
        if (blob.data == NULL) {
                return NT_STATUS_NO_MEMORY;
        }

        status = packet_send(sock->packet, blob);
        if (!NT_STATUS_IS_OK(status)) {
                return status;
        }

        if (trigger_read) {
                sock_send_read(p);
        }

        return NT_STATUS_OK;
}

/* 
   shutdown sock pipe connection
*/
static NTSTATUS sock_shutdown_pipe(struct dcerpc_connection *p, NTSTATUS status)
{
        struct sock_private *sock = (struct sock_private *)p->transport.private_data;

        if (sock && sock->sock) {
                sock_dead(p, status);
        }

        return status;
}

/*
  return sock server name
*/
static const char *sock_peer_name(struct dcerpc_connection *p)
{
        struct sock_private *sock = talloc_get_type(p->transport.private_data, struct sock_private);
        return sock->server_name;
}

/*
  return remote name we make the actual connection (good for kerberos) 
*/
static const char *sock_target_hostname(struct dcerpc_connection *p)
{
        struct sock_private *sock = talloc_get_type(p->transport.private_data, struct sock_private);
        return sock->server_name;
}


struct pipe_open_socket_state {
        struct dcerpc_connection *conn;
        struct socket_context *socket_ctx;
        struct sock_private *sock;
        struct socket_address *server;
        const char *target_hostname;
        enum dcerpc_transport_t transport;
};


static void continue_socket_connect(struct composite_context *ctx)
{
        struct dcerpc_connection *conn;
        struct sock_private *sock;
        struct composite_context *c = talloc_get_type(ctx->async.private_data,
                                                      struct composite_context);
        struct pipe_open_socket_state *s = talloc_get_type(c->private_data,
                                                           struct pipe_open_socket_state);

        /* make it easier to write a function calls */
        conn = s->conn;
        sock = s->sock;

        c->status = socket_connect_recv(ctx);
        if (!NT_STATUS_IS_OK(c->status)) {
                DEBUG(0, ("Failed to connect host %s on port %d - %s\n", 
                          s->server->addr, s->server->port,
                          nt_errstr(c->status)));
                composite_error(c, c->status);
                return;
        }

        /*
          fill in the transport methods
        */
        conn->transport.transport       = s->transport;
        conn->transport.private_data    = NULL;

        conn->transport.send_request    = sock_send_request;
        conn->transport.send_read       = sock_send_read;
        conn->transport.recv_data       = NULL;

        conn->transport.shutdown_pipe   = sock_shutdown_pipe;
        conn->transport.peer_name       = sock_peer_name;
        conn->transport.target_hostname = sock_target_hostname;

        sock->sock          = s->socket_ctx;
        sock->pending_reads = 0;
        sock->server_name   = strupper_talloc(sock, s->target_hostname);

        sock->fde = event_add_fd(conn->event_ctx, sock->sock, socket_get_fd(sock->sock),
                                 EVENT_FD_READ, sock_io_handler, conn);
        
        conn->transport.private_data = sock;

        sock->packet = packet_init(sock);
        if (sock->packet == NULL) {
                composite_error(c, NT_STATUS_NO_MEMORY);
                talloc_free(sock);
                return;
        }

        packet_set_private(sock->packet, conn);
        packet_set_socket(sock->packet, sock->sock);
        packet_set_callback(sock->packet, sock_process_recv);
        packet_set_full_request(sock->packet, sock_complete_packet);
        packet_set_error_handler(sock->packet, sock_error_handler);
        packet_set_event_context(sock->packet, conn->event_ctx);
        packet_set_fde(sock->packet, sock->fde);
        packet_set_serialise(sock->packet);
        packet_set_initial_read(sock->packet, 16);

        /* ensure we don't get SIGPIPE */
        BlockSignals(true, SIGPIPE);

        composite_done(c);
}


static struct composite_context *dcerpc_pipe_open_socket_send(TALLOC_CTX *mem_ctx,
                                                       struct dcerpc_connection *cn,
                                                       struct socket_address *server,
                                                       const char *target_hostname,
                                                       const char *full_path,
                                                       enum dcerpc_transport_t transport)
{
        struct composite_context *c;
        struct pipe_open_socket_state *s;
        struct composite_context *conn_req;

        c = composite_create(mem_ctx, cn->event_ctx);
        if (c == NULL) return NULL;

        s = talloc_zero(c, struct pipe_open_socket_state);
        if (composite_nomem(s, c)) return c;
        c->private_data = s;

        s->conn      = cn;
        s->transport = transport;
        s->server    = talloc_reference(c, server);
        if (composite_nomem(s->server, c)) return c;
        s->target_hostname = talloc_reference(s, target_hostname);

        s->sock = talloc(cn, struct sock_private);
        if (composite_nomem(s->sock, c)) return c;

        c->status = socket_create(server->family, SOCKET_TYPE_STREAM, &s->socket_ctx, 0);
        if (!composite_is_ok(c)) return c;

        talloc_steal(s->sock, s->socket_ctx);

        s->sock->path = talloc_reference(s->sock, full_path);

        conn_req = socket_connect_send(s->socket_ctx, NULL, s->server, 0, 
                                       c->event_ctx);
        composite_continue(c, conn_req, continue_socket_connect, c);
        return c;
}


static NTSTATUS dcerpc_pipe_open_socket_recv(struct composite_context *c)
{
        NTSTATUS status = composite_wait(c);

        talloc_free(c);
        return status;
}

struct pipe_tcp_state {
        const char *server;
        const char *target_hostname;
        const char *address;
        uint32_t port;
        struct socket_address *srvaddr;
        struct resolve_context *resolve_ctx;
        struct dcerpc_connection *conn;
};


#if 0 /* disabled till we can resolve names to ipv6 addresses */
static void continue_ipv6_open_socket(struct composite_context *ctx);
#endif
static void continue_ipv4_open_socket(struct composite_context *ctx);
static void continue_ip_resolve_name(struct composite_context *ctx);

static void continue_ip_resolve_name(struct composite_context *ctx)
{
        struct composite_context *c = talloc_get_type(ctx->async.private_data,
                                                      struct composite_context);
        struct pipe_tcp_state *s = talloc_get_type(c->private_data,
                                                   struct pipe_tcp_state);
        struct composite_context *sock_ipv4_req;

        c->status = resolve_name_recv(ctx, s, &s->address);
        if (!composite_is_ok(c)) return;

        /* prepare server address using host ip:port and transport name */
        s->srvaddr = socket_address_from_strings(s->conn, "ipv4", s->address, s->port);
        if (composite_nomem(s->srvaddr, c)) return;

        /* resolve_nbt_name gives only ipv4 ... - send socket open request */
        sock_ipv4_req = dcerpc_pipe_open_socket_send(c, s->conn,
                                                     s->srvaddr, s->target_hostname,
                                                     NULL,
                                                     NCACN_IP_TCP);
        composite_continue(c, sock_ipv4_req, continue_ipv4_open_socket, c);
}

/*
  Stage 2 of dcerpc_pipe_open_tcp_send: receive result of pipe open request
  on IPv6 and send the request on IPv4 unless IPv6 transport succeeded.
*/
#if 0 /* disabled till we can resolve names to ipv6 addresses */
static void continue_ipv6_open_socket(struct composite_context *ctx)
{
        struct composite_context *c = talloc_get_type(ctx->async.private_data,
                                                      struct composite_context);
        struct pipe_tcp_state *s = talloc_get_type(c->private_data,
                                                   struct pipe_tcp_state);
        struct composite_context *sock_ipv4_req;

        /* receive result of socket open request */
        c->status = dcerpc_pipe_open_socket_recv(ctx);
        if (NT_STATUS_IS_OK(c->status)) {
                composite_done(c);
                return;
        }

        talloc_free(s->srvaddr);

        /* prepare server address using host:ip and transport name */
        s->srvaddr = socket_address_from_strings(s->conn, "ipv4", s->address, s->port);
        if (composite_nomem(s->srvaddr, c)) return;

        /* try IPv4 if IPv6 fails */
        sock_ipv4_req = dcerpc_pipe_open_socket_send(c, s->conn, 
                                                     s->srvaddr, s->target_hostname, 
                                                     NCACN_IP_TCP);
        composite_continue(c, sock_ipv4_req, continue_ipv4_open_socket, c);
}
#endif

/*
  Stage 2 of dcerpc_pipe_open_tcp_send: receive result of pipe open request
  on IPv4 transport.
*/
static void continue_ipv4_open_socket(struct composite_context *ctx)
{
        struct composite_context *c = talloc_get_type(ctx->async.private_data,
                                                      struct composite_context);
        struct pipe_tcp_state *s = talloc_get_type(c->private_data,
                                                   struct pipe_tcp_state);
        
        /* receive result socket open request */
        c->status = dcerpc_pipe_open_socket_recv(ctx);
        if (!NT_STATUS_IS_OK(c->status)) {
                /* something went wrong... */
                DEBUG(0, ("Failed to connect host %s (%s) on port %d - %s.\n",
                          s->address, s->target_hostname, 
                          s->port, nt_errstr(c->status)));

                composite_error(c, c->status);
                return;
        }

        composite_done(c);
}


/*
  Send rpc pipe open request to given host:port using
  tcp/ip transport
*/
struct composite_context* dcerpc_pipe_open_tcp_send(struct dcerpc_connection *conn,
                                                    const char *server,
                                                    const char *target_hostname,
                                                    uint32_t port,
                                                    struct resolve_context *resolve_ctx)
{
        struct composite_context *c;
        struct pipe_tcp_state *s;
        struct composite_context *resolve_req;
        struct nbt_name name;

        /* composite context allocation and setup */
        c = composite_create(conn, conn->event_ctx);
        if (c == NULL) return NULL;

        s = talloc_zero(c, struct pipe_tcp_state);
        if (composite_nomem(s, c)) return c;
        c->private_data = s;

        /* store input parameters in state structure */
        s->server          = talloc_strdup(c, server);
        if (composite_nomem(s->server, c)) return c;
        if (target_hostname) {
                s->target_hostname = talloc_strdup(c, target_hostname);
                if (composite_nomem(s->target_hostname, c)) return c;
        }
        s->port            = port;
        s->conn            = conn;
        s->resolve_ctx     = resolve_ctx;

        make_nbt_name_server(&name, server);
        resolve_req = resolve_name_send(resolve_ctx, s, &name, c->event_ctx);
        composite_continue(c, resolve_req, continue_ip_resolve_name, c);
        return c;
}

/*
  Receive result of pipe open request on tcp/ip
*/
NTSTATUS dcerpc_pipe_open_tcp_recv(struct composite_context *c)
{
        NTSTATUS status;
        status = composite_wait(c);

        talloc_free(c);
        return status;
}


struct pipe_unix_state {
        const char *path;
        struct socket_address *srvaddr;
        struct dcerpc_connection *conn;
};


/*
  Stage 2 of dcerpc_pipe_open_unix_stream_send: receive result of pipe open
  request on unix socket.
*/
static void continue_unix_open_socket(struct composite_context *ctx)
{
        struct composite_context *c = talloc_get_type(ctx->async.private_data,
                                                      struct composite_context);

        c->status = dcerpc_pipe_open_socket_recv(ctx);
        if (NT_STATUS_IS_OK(c->status)) {
                composite_done(c);
                return;
        }

        composite_error(c, c->status);
}


/*
  Send pipe open request on unix socket
*/
struct composite_context *dcerpc_pipe_open_unix_stream_send(struct dcerpc_connection *conn,
                                                            const char *path)
{
        struct composite_context *c;
        struct composite_context *sock_unix_req;
        struct pipe_unix_state *s;

        /* composite context allocation and setup */
        c = composite_create(conn, conn->event_ctx);
        if (c == NULL) return NULL;

        s = talloc_zero(c, struct pipe_unix_state);
        if (composite_nomem(s, c)) return c;
        c->private_data = s;

        /* store parameters in state structure */
        s->path = talloc_strdup(c, path);
        if (composite_nomem(s->path, c)) return c;
        s->conn = conn;

        /* prepare server address using socket path and transport name */
        s->srvaddr = socket_address_from_strings(conn, "unix", s->path, 0);
        if (composite_nomem(s->srvaddr, c)) return c;

        /* send socket open request */
        sock_unix_req = dcerpc_pipe_open_socket_send(c, s->conn, 
                                                     s->srvaddr, NULL,
                                                     s->path,
                                                     NCALRPC);
        composite_continue(c, sock_unix_req, continue_unix_open_socket, c);
        return c;
}


/*
  Receive result of pipe open request on unix socket
*/
NTSTATUS dcerpc_pipe_open_unix_stream_recv(struct composite_context *c)
{
        NTSTATUS status = composite_wait(c);

        talloc_free(c);
        return status;
}


/*
  Stage 2 of dcerpc_pipe_open_pipe_send: receive socket open request
*/
static void continue_np_open_socket(struct composite_context *ctx)
{
        struct composite_context *c = talloc_get_type(ctx->async.private_data,
                                                      struct composite_context);

        c->status = dcerpc_pipe_open_socket_recv(ctx);
        if (!composite_is_ok(c)) return;

        composite_done(c);
}


/*
  Send pipe open request on ncalrpc
*/
struct composite_context* dcerpc_pipe_open_pipe_send(struct dcerpc_connection *conn,
                                                     const char *ncalrpc_dir,
                                                     const char *identifier)
{
        char *canon = NULL;

        struct composite_context *c;
        struct composite_context *sock_np_req;
        struct pipe_unix_state *s;

        /* composite context allocation and setup */
        c = composite_create(conn, conn->event_ctx);
        if (c == NULL) return NULL;

        s = talloc_zero(c, struct pipe_unix_state);
        if (composite_nomem(s, c)) return c;
        c->private_data = s;

        /* store parameters in state structure */
        canon = talloc_strdup(s, identifier);
        if (composite_nomem(canon, c)) return c;
        s->conn = conn;

        string_replace(canon, '/', '\\');
        s->path = talloc_asprintf(canon, "%s/%s", ncalrpc_dir, canon);
        if (composite_nomem(s->path, c)) return c;

        /* prepare server address using path and transport name */
        s->srvaddr = socket_address_from_strings(conn, "unix", s->path, 0);
        if (composite_nomem(s->srvaddr, c)) return c;

        /* send socket open request */
        sock_np_req = dcerpc_pipe_open_socket_send(c, s->conn, s->srvaddr, NULL, s->path, NCALRPC);
        composite_continue(c, sock_np_req, continue_np_open_socket, c);
        return c;
}


/*
  Receive result of pipe open request on ncalrpc
*/
NTSTATUS dcerpc_pipe_open_pipe_recv(struct composite_context *c)
{
        NTSTATUS status = composite_wait(c);
        
        talloc_free(c);
        return status;
}


/*
  Open a rpc pipe on a named pipe - sync version
*/
NTSTATUS dcerpc_pipe_open_pipe(struct dcerpc_connection *conn, const char *ncalrpc_dir, const char *identifier)
{
        struct composite_context *c = dcerpc_pipe_open_pipe_send(conn, ncalrpc_dir, identifier);
        return dcerpc_pipe_open_pipe_recv(c);
}

const char *dcerpc_unix_socket_path(struct dcerpc_connection *p)
{
        struct sock_private *sock = (struct sock_private *)p->transport.private_data;
        return sock->path;
}

struct socket_address *dcerpc_socket_peer_addr(struct dcerpc_connection *p, TALLOC_CTX *mem_ctx)
{
        struct sock_private *sock = (struct sock_private *)p->transport.private_data;
        return socket_get_peer_addr(sock->sock, mem_ctx);
}