rpc_transport.c

这是一个开放源代码的与WINNT/WIN2K/WIN2003兼容的操作系统

        /* need a non-blocking socket, otherwise accept() has a potential
         * race-condition (poll() says it is readable, connection drops,
         * and accept() blocks until the next connection comes...)
         */
        blocking = 1;
        ret = ioctlsocket(sock, FIONBIO, &blocking);
        if (ret < 0)
        {
            WARN("couldn't make socket non-blocking, error %d\n", ret);
            RPCRT4_DestroyConnection(&tcpc->common);
            status = RPC_S_OUT_OF_RESOURCES;
            continue;
        }

        tcpc->common.Next = first_connection;
        first_connection = &tcpc->common;
    }

    freeaddrinfo(ai);

    /* if at least one connection was created for an endpoint then
     * return success */
    if (first_connection)
    {
        RpcConnection *conn;

        /* find last element in list */
        for (conn = first_connection; conn->Next; conn = conn->Next)
            ;

        EnterCriticalSection(&protseq->cs);
        conn->Next = protseq->conn;
        protseq->conn = first_connection;
        LeaveCriticalSection(&protseq->cs);
        
        TRACE("listening on %s\n", endpoint);
        return RPC_S_OK;
    }

    ERR("couldn't listen on port %s\n", endpoint);
    return status;
}

static RPC_STATUS rpcrt4_conn_tcp_handoff(RpcConnection *old_conn, RpcConnection *new_conn)
{
  int ret;
  struct sockaddr_in address;
  socklen_t addrsize;
  u_long blocking;
  RpcConnection_tcp *server = (RpcConnection_tcp*) old_conn;
  RpcConnection_tcp *client = (RpcConnection_tcp*) new_conn;

  addrsize = sizeof(address);
  ret = accept(server->sock, (struct sockaddr*) &address, &addrsize);
  if (ret < 0)
  {
    ERR("Failed to accept a TCP connection: error %d\n", ret);
    return RPC_S_OUT_OF_RESOURCES;
  }
  /* reset to blocking behaviour */
  blocking = 0;
  ret = ioctlsocket(ret, FIONBIO, &blocking);
  client->sock = ret;
  TRACE("Accepted a new TCP connection\n");
  return RPC_S_OK;
}

static int rpcrt4_conn_tcp_read(RpcConnection *Connection,
                                void *buffer, unsigned int count)
{
  RpcConnection_tcp *tcpc = (RpcConnection_tcp *) Connection;
  int r = recv(tcpc->sock, buffer, count, MSG_WAITALL);
  TRACE("%d %p %u -> %d\n", tcpc->sock, buffer, count, r);
  return r;
}

static int rpcrt4_conn_tcp_write(RpcConnection *Connection,
                                 const void *buffer, unsigned int count)
{
  RpcConnection_tcp *tcpc = (RpcConnection_tcp *) Connection;
  int r = write(tcpc->sock, buffer, count);
  TRACE("%d %p %u -> %d\n", tcpc->sock, buffer, count, r);
  return r;
}

static int rpcrt4_conn_tcp_close(RpcConnection *Connection)
{
  RpcConnection_tcp *tcpc = (RpcConnection_tcp *) Connection;

  TRACE("%d\n", tcpc->sock);

  if (tcpc->sock != -1)
    close(tcpc->sock);
  tcpc->sock = -1;
  return 0;
}

static size_t rpcrt4_ncacn_ip_tcp_get_top_of_tower(unsigned char *tower_data,
                                                   const char *networkaddr,
                                                   const char *endpoint)
{
    twr_tcp_floor_t *tcp_floor;
    twr_ipv4_floor_t *ipv4_floor;
    struct addrinfo *ai;
    struct addrinfo hints;
    int ret;
    size_t size = sizeof(*tcp_floor) + sizeof(*ipv4_floor);

    TRACE("(%p, %s, %s)\n", tower_data, networkaddr, endpoint);

    if (!tower_data)
        return size;

    tcp_floor = (twr_tcp_floor_t *)tower_data;
    tower_data += sizeof(*tcp_floor);

    ipv4_floor = (twr_ipv4_floor_t *)tower_data;

    tcp_floor->count_lhs = sizeof(tcp_floor->protid);
    tcp_floor->protid = EPM_PROTOCOL_TCP;
    tcp_floor->count_rhs = sizeof(tcp_floor->port);

    ipv4_floor->count_lhs = sizeof(ipv4_floor->protid);
    ipv4_floor->protid = EPM_PROTOCOL_IP;
    ipv4_floor->count_rhs = sizeof(ipv4_floor->ipv4addr);

    hints.ai_flags          = AI_NUMERICHOST;
    /* FIXME: only support IPv4 at the moment. how is IPv6 represented by the EPM? */
    hints.ai_family         = PF_INET;
    hints.ai_socktype       = SOCK_STREAM;
    hints.ai_protocol       = IPPROTO_TCP;
    hints.ai_addrlen        = 0;
    hints.ai_addr           = NULL;
    hints.ai_canonname      = NULL;
    hints.ai_next           = NULL;

    ret = getaddrinfo(networkaddr, endpoint, &hints, &ai);
    if (ret)
    {
        ret = getaddrinfo("0.0.0.0", endpoint, &hints, &ai);
        if (ret)
        {
            ERR("getaddrinfo failed: %s\n", gai_strerror(ret));
            return 0;
        }
    }

    if (ai->ai_family == PF_INET)
    {
        const struct sockaddr_in *sin = (const struct sockaddr_in *)ai->ai_addr;
        tcp_floor->port = sin->sin_port;
        ipv4_floor->ipv4addr = sin->sin_addr.s_addr;
    }
    else
    {
        ERR("unexpected protocol family %d\n", ai->ai_family);
        return 0;
    }

    freeaddrinfo(ai);

    return size;
}

static RPC_STATUS rpcrt4_ncacn_ip_tcp_parse_top_of_tower(const unsigned char *tower_data,
                                                         size_t tower_size,
                                                         char **networkaddr,
                                                         char **endpoint)
{
    const twr_tcp_floor_t *tcp_floor = (const twr_tcp_floor_t *)tower_data;
    const twr_ipv4_floor_t *ipv4_floor;
    struct in_addr in_addr;

    TRACE("(%p, %d, %p, %p)\n", tower_data, (int)tower_size, networkaddr, endpoint);

    if (tower_size < sizeof(*tcp_floor))
        return EPT_S_NOT_REGISTERED;

    tower_data += sizeof(*tcp_floor);
    tower_size -= sizeof(*tcp_floor);

    if (tower_size < sizeof(*ipv4_floor))
        return EPT_S_NOT_REGISTERED;

    ipv4_floor = (const twr_ipv4_floor_t *)tower_data;

    if ((tcp_floor->count_lhs != sizeof(tcp_floor->protid)) ||
        (tcp_floor->protid != EPM_PROTOCOL_TCP) ||
        (tcp_floor->count_rhs != sizeof(tcp_floor->port)) ||
        (ipv4_floor->count_lhs != sizeof(ipv4_floor->protid)) ||
        (ipv4_floor->protid != EPM_PROTOCOL_IP) ||
        (ipv4_floor->count_rhs != sizeof(ipv4_floor->ipv4addr)))
        return EPT_S_NOT_REGISTERED;

    if (endpoint)
    {
        *endpoint = I_RpcAllocate(6 /* sizeof("65535") + 1 */);
        if (!*endpoint)
            return RPC_S_OUT_OF_RESOURCES;
        sprintf(*endpoint, "%u", ntohs(tcp_floor->port));
    }

    if (networkaddr)
    {
        *networkaddr = I_RpcAllocate(INET_ADDRSTRLEN);
        if (!*networkaddr)
        {
            if (endpoint)
            {
                I_RpcFree(*endpoint);
                *endpoint = NULL;
            }
            return RPC_S_OUT_OF_RESOURCES;
        }
        in_addr.s_addr = ipv4_floor->ipv4addr;
        if (!inet_ntop(AF_INET, &in_addr, *networkaddr, INET_ADDRSTRLEN))
        {
            ERR("inet_ntop: %s\n", strerror(errno));
            I_RpcFree(*networkaddr);
            *networkaddr = NULL;
            if (endpoint)
            {
                I_RpcFree(*endpoint);
                *endpoint = NULL;
            }
            return EPT_S_NOT_REGISTERED;
        }
    }

    return RPC_S_OK;
}

typedef struct _RpcServerProtseq_sock
{
    RpcServerProtseq common;
    int mgr_event_rcv;
    int mgr_event_snd;
} RpcServerProtseq_sock;

static RpcServerProtseq *rpcrt4_protseq_sock_alloc(void)
{
    RpcServerProtseq_sock *ps = HeapAlloc(GetProcessHeap(), 0, sizeof(*ps));
    if (ps)
    {
        int fds[2];
        u_long blocking;
        if (!socketpair(PF_UNIX, SOCK_DGRAM, 0, fds))
        {
            blocking = 1;
            ioctlsocket(fds[0], FIONBIO, &blocking);
            ioctlsocket(fds[1], FIONBIO, &blocking);
            ps->mgr_event_rcv = fds[0];
            ps->mgr_event_snd = fds[1];
        }
        else
        {
            ERR("socketpair failed with error %s\n", strerror(errno));
            HeapFree(GetProcessHeap(), 0, ps);
            return NULL;
        }
    }
    return &ps->common;
}

static void rpcrt4_protseq_sock_signal_state_changed(RpcServerProtseq *protseq)
{
    RpcServerProtseq_sock *sockps = CONTAINING_RECORD(protseq, RpcServerProtseq_sock, common);
    char dummy = 1;
    write(sockps->mgr_event_snd, &dummy, sizeof(dummy));
}

static void *rpcrt4_protseq_sock_get_wait_array(RpcServerProtseq *protseq, void *prev_array, unsigned int *count)
{
    struct pollfd *poll_info = prev_array;
    RpcConnection_tcp *conn;
    RpcServerProtseq_sock *sockps = CONTAINING_RECORD(protseq, RpcServerProtseq_sock, common);

    EnterCriticalSection(&protseq->cs);
    
    /* open and count connections */
    *count = 1;
    conn = (RpcConnection_tcp *)protseq->conn;
    while (conn) {
        if (conn->sock != -1)
            (*count)++;
        conn = (RpcConnection_tcp *)conn->common.Next;
    }
    
    /* make array of connections */
    if (poll_info)
        poll_info = HeapReAlloc(GetProcessHeap(), 0, poll_info, *count*sizeof(*poll_info));
    else
        poll_info = HeapAlloc(GetProcessHeap(), 0, *count*sizeof(*poll_info));
    if (!poll_info)
    {
        ERR("couldn't allocate poll_info\n");
        LeaveCriticalSection(&protseq->cs);
        return NULL;
    }

    poll_info[0].fd = sockps->mgr_event_rcv;
    poll_info[0].events = POLLIN;
    *count = 1;
    conn =  CONTAINING_RECORD(protseq->conn, RpcConnection_tcp, common);
    while (conn) {
        if (conn->sock != -1)
        {
            poll_info[*count].fd = conn->sock;
            poll_info[*count].events = POLLIN;
            (*count)++;
        }
        conn = CONTAINING_RECORD(conn->common.Next, RpcConnection_tcp, common);
    }
    LeaveCriticalSection(&protseq->cs);
    return poll_info;
}

static void rpcrt4_protseq_sock_free_wait_array(RpcServerProtseq *protseq, void *array)
{
    HeapFree(GetProcessHeap(), 0, array);
}

static int rpcrt4_protseq_sock_wait_for_new_connection(RpcServerProtseq *protseq, unsigned int count, void *wait_array)
{
    struct pollfd *poll_info = wait_array;
    int ret, i;
    RpcConnection *cconn;
    RpcConnection_tcp *conn;
    
    if (!poll_info)
        return -1;

    ret = poll(poll_info, count, -1);
    if (ret < 0)
    {
        ERR("poll failed with error %d\n", ret);
        return -1;
    }

    for (i = 0; i < count; i++)
        if (poll_info[i].revents & POLLIN)
        {
            /* RPC server event */
            if (i == 0)
            {
                char dummy;
                read(poll_info[0].fd, &dummy, sizeof(dummy));
                return 0;
            }

            /* find which connection got a RPC */
            EnterCriticalSection(&protseq->cs);
            conn = CONTAINING_RECORD(protseq->conn, RpcConnection_tcp, common);
            while (conn) {
                if (poll_info[i].fd == conn->sock) break;
                conn = CONTAINING_RECORD(conn->common.Next, RpcConnection_tcp, common);
            }
            cconn = NULL;
            if (conn)
                RPCRT4_SpawnConnection(&cconn, &conn->common);
            else
                ERR("failed to locate connection for fd %d\n", poll_info[i].fd);
            LeaveCriticalSection(&protseq->cs);
            if (cconn)
                RPCRT4_new_client(cconn);
            else
                return -1;
        }

    return 1;
}

static const struct connection_ops conn_protseq_list[] = {
  { "ncacn_np",
    { EPM_PROTOCOL_NCACN, EPM_PROTOCOL_SMB },
    rpcrt4_conn_np_alloc,
    rpcrt4_ncacn_np_open,
    rpcrt4_ncacn_np_handoff,
    rpcrt4_conn_np_read,
    rpcrt4_conn_np_write,
    rpcrt4_conn_np_close,
    rpcrt4_ncacn_np_get_top_of_tower,
    rpcrt4_ncacn_np_parse_top_of_tower,
  },
  { "ncalrpc",
    { EPM_PROTOCOL_NCALRPC, EPM_PROTOCOL_PIPE },
    rpcrt4_conn_np_alloc,
    rpcrt4_ncalrpc_open,
    rpcrt4_ncalrpc_handoff,
    rpcrt4_conn_np_read,
    rpcrt4_conn_np_write,
    rpcrt4_conn_np_close,
    rpcrt4_ncalrpc_get_top_of_tower,
    rpcrt4_ncalrpc_parse_top_of_tower,
  },
  { "ncacn_ip_tcp",
    { EPM_PROTOCOL_NCACN, EPM_PROTOCOL_TCP },
    rpcrt4_conn_tcp_alloc,
    rpcrt4_ncacn_ip_tcp_open,
    rpcrt4_conn_tcp_handoff,
    rpcrt4_conn_tcp_read,
    rpcrt4_conn_tcp_write,
    rpcrt4_conn_tcp_close,
    rpcrt4_ncacn_ip_tcp_get_top_of_tower,
    rpcrt4_ncacn_ip_tcp_parse_top_of_tower,
  }
};


static const struct protseq_ops protseq_list[] =
{
    {
        "ncacn_np",
        rpcrt4_protseq_np_alloc,
        rpcrt4_protseq_np_signal_state_changed,
        rpcrt4_protseq_np_get_wait_array,
        rpcrt4_protseq_np_free_wait_array,
        rpcrt4_protseq_np_wait_for_new_connection,
        rpcrt4_protseq_ncacn_np_open_endpoint,
    },
    {
        "ncalrpc",
        rpcrt4_protseq_np_alloc,
        rpcrt4_protseq_np_signal_state_changed,
        rpcrt4_protseq_np_get_wait_array,
        rpcrt4_protseq_np_free_wait_array,
        rpcrt4_protseq_np_wait_for_new_connection,
        rpcrt4_protseq_ncalrpc_open_endpoint,
    },
    {
        "ncacn_ip_tcp",
        rpcrt4_protseq_sock_alloc,
        rpcrt4_protseq_sock_signal_state_changed,
        rpcrt4_protseq_sock_get_wait_array,
        rpcrt4_protseq_sock_free_wait_array,
        rpcrt4_protseq_sock_wait_for_new_connection,
        rpcrt4_protseq_ncacn_ip_tcp_open_endpoint,
    },
};

#define ARRAYSIZE(a) (sizeof((a)) / sizeof((a)[0]))