lib/socket: minimal update to `SocketObserver` API and note some problems

[nit.git] / lib / socket / socket_c.nit

# This file is part of NIT ( http://www.nitlanguage.org ).
#
# Copyright 2013 Matthieu Lucas <lucasmatthieu@gmail.com>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# Low-level socket functionalities
module socket_c

in "C Header" `{
        #include <stdio.h>
        #include <stdlib.h>
        #include <unistd.h>
        #include <string.h>
        #include <sys/socket.h>
        #include <sys/types.h>
        #include <netinet/in.h>
        #include <arpa/inet.h>
        #include <netdb.h>
        #include <sys/poll.h>
`}

in "C" `{
        #include <fcntl.h>
        #include <netinet/tcp.h>
`}

# Wrapper for the data structure PollFD used for polling on a socket
class PollFD

        # The PollFD object
        private var poll_struct: NativeSocketPollFD

        # A collection of the events to be watched
        var events: Array[NativeSocketPollValues]

        init(pid: Int, events: Array[NativeSocketPollValues])
        do
                assert events.length >= 1
                self.events = events

                var events_in_one = events[0]

                for i in [1 .. events.length-1] do
                        events_in_one += events[i]
                end

                self.poll_struct = new NativeSocketPollFD(pid, events_in_one)
        end

        # Reads the response and returns an array with the type of events that have been found
        private fun check_response(response: Int): Array[NativeSocketPollValues]
        do
                var resp_array = new Array[NativeSocketPollValues]
                for i in events do
                        if c_check_resp(response, i) != 0 then
                                resp_array.push(i)
                        end
                end
                return resp_array
        end

        # Checks if the poll call has returned true for a particular type of event
        private fun c_check_resp(response: Int, mask: NativeSocketPollValues): Int
        `{
                return response & mask;
        `}

end

# Data structure used by the poll function
private extern class NativeSocketPollFD `{ struct pollfd `}

        # File descriptor id
        private fun fd: Int `{ return recv.fd; `}

        # List of events to be watched
        private fun events: Int `{ return recv.events; `}

        # List of events received by the last poll function
        private fun revents: Int `{  return recv.revents; `}

        new (pid: Int, events: NativeSocketPollValues) `{
                struct pollfd poll;
                poll.fd = pid;
                poll.events = events;
                return poll;
        `}

end

extern class NativeSocket `{ int* `}

        new socket(domain: NativeSocketAddressFamilies, socketType: NativeSocketTypes, protocol: NativeSocketProtocolFamilies) `{
                int ds = socket(domain, socketType, protocol);
                if(ds == -1){
                        return NULL;
                }
                int *d = malloc(sizeof(int));
                memcpy(d, &ds, sizeof(ds));
                return d;
        `}

        fun destroy `{ free(recv); `}

        fun close: Int `{ return close(*recv); `}

        fun descriptor: Int `{ return *recv; `}

        fun gethostbyname(n: String): NativeSocketHostent import String.to_cstring `{ return gethostbyname(String_to_cstring(n)); `}

        fun connect(addrIn: NativeSocketAddrIn): Int `{
                return connect(*recv, (struct sockaddr*)addrIn, sizeof(*addrIn));
        `}

        fun write(buffer: String): Int
        import String.to_cstring, String.length `{
                return write(*recv, (char*)String_to_cstring(buffer), String_length(buffer));
        `}

        fun read: String import NativeString.to_s_with_length `{
                static char c[1024];
                int n = read(*recv, c, 1024);
                if(n < 0) {
                        return NativeString_to_s_with_length("",0);
                }
                char* ret = malloc(n + 1);
                memcpy(ret, c, n);
                ret[n] = '\0';
                return NativeString_to_s_with_length(ret, n);
        `}

        # Sets an option for the socket
        fun setsockopt(level: NativeSocketOptLevels, option_name: NativeSocketOptNames, option_value: Int) `{
                int err = setsockopt(*recv, level, option_name, &option_value, sizeof(int));
                if(err != 0){
                        perror("Error on setsockopts: ");
                        exit(1);
                }
        `}

        fun bind(addrIn: NativeSocketAddrIn): Int `{ return bind(*recv, (struct sockaddr*)addrIn, sizeof(*addrIn)); `}

        fun listen(size: Int): Int `{ return listen(*recv, size); `}

        # Checks if the buffer is ready for any event specified when creating the pollfd structure
        fun socket_poll(filedesc: PollFD, timeout: Int): Array[NativeSocketPollValues]
        do
                var result = native_poll(filedesc.poll_struct, timeout)
                assert result != -1
                return filedesc.check_response(result)
        end

        # Call to the poll function of the C socket
        #
        # Signature:
        # int poll(struct pollfd fds[], nfds_t nfds, int timeout);
        #
        # Official documentation of the poll function:
        #
        # The poll() function provides applications with a mechanism for multiplexing input/output over a set of file descriptors.
        # For each member of the array pointed to by fds, poll() shall examine the given file descriptor for the event(s) specified in events.
        # The number of pollfd structures in the fds array is specified by nfds.
        # The poll() function shall identify those file descriptors on which an application can read or write data, or on which certain events have occurred.
        # The fds argument specifies the file descriptors to be examined and the events of interest for each file descriptor.
        # It is a pointer to an array with one member for each open file descriptor of interest.
        # The array's members are pollfd structures within which fd specifies an open file descriptor and events and revents are bitmasks constructed by
        # OR'ing a combination of the pollfd flags.
        private fun native_poll(filedesc: NativeSocketPollFD, timeout: Int): Int `{
                int poll_return = poll(&filedesc, 1, timeout);
                return poll_return;
        `}

        private fun native_accept(addr_in: NativeSocketAddrIn): NativeSocket `{
                socklen_t s = sizeof(struct sockaddr);
                int socket = accept(*recv, (struct sockaddr*)addr_in, &s);
                if (socket == -1) return NULL;

                int *ptr = malloc(sizeof(int));
                *ptr = socket;
                return ptr;
        `}

        fun accept: nullable SocketAcceptResult
        do
                var addrIn = new NativeSocketAddrIn
                var s = native_accept(addrIn)
                if s.address_is_null then return null
                return new SocketAcceptResult(s, addrIn)
        end

        # Set wether this socket is non blocking
        fun non_blocking=(value: Bool) `{
                int flags = fcntl(*recv, F_GETFL, 0);
                if (flags == -1) flags = 0;

                if (value) {
                        flags = flags | O_NONBLOCK;
                } else if (flags & O_NONBLOCK) {
                        flags = flags - O_NONBLOCK;
                } else {
                        return;
                }
                fcntl(*recv, F_SETFL, flags);
        `}
end

# Result of a call to `NativeSocket::accept`
class SocketAcceptResult

        # Opened socket
        var socket: NativeSocket

        # Address of the remote client
        var addr_in: NativeSocketAddrIn
end

extern class NativeSocketAddrIn `{ struct sockaddr_in* `}
        new `{
                struct sockaddr_in *sai = NULL;
                sai = malloc(sizeof(struct sockaddr_in));
                return sai;
        `}

        new with(port: Int, family: NativeSocketAddressFamilies) `{
                struct sockaddr_in *sai = NULL;
                sai = malloc(sizeof(struct sockaddr_in));
                sai->sin_family = family;
                sai->sin_port = htons(port);
                sai->sin_addr.s_addr = INADDR_ANY;
                return sai;
        `}

        new with_hostent(hostent: NativeSocketHostent, port: Int) `{
                struct sockaddr_in *sai = NULL;
                sai = malloc(sizeof(struct sockaddr_in));
                sai->sin_family = hostent->h_addrtype;
                sai->sin_port = htons(port);
                memcpy((char*)&sai->sin_addr.s_addr, (char*)hostent->h_addr, hostent->h_length);
                return sai;
        `}

        fun address: String import NativeString.to_s `{ return NativeString_to_s((char*)inet_ntoa(recv->sin_addr)); `}

        fun family: NativeSocketAddressFamilies `{ return recv->sin_family; `}

        fun port: Int `{ return ntohs(recv->sin_port); `}

        fun destroy `{ free(recv); `}
end

extern class NativeSocketHostent `{ struct hostent* `}
        private fun native_h_aliases(i: Int): String import NativeString.to_s `{ return NativeString_to_s(recv->h_aliases[i]); `}

        private fun native_h_aliases_reachable(i: Int): Bool `{ return (recv->h_aliases[i] != NULL); `}

        fun h_aliases: Array[String]
        do
                var i=0
                var d=new Array[String]
                loop
                        d.add(native_h_aliases(i))
                        if native_h_aliases_reachable(i+1) == false then break
                        i += 1
                end
                return d
        end

        fun h_addr: String import NativeString.to_s `{ return NativeString_to_s((char*)inet_ntoa(*(struct in_addr*)recv->h_addr)); `}

        fun h_addrtype: Int `{ return recv->h_addrtype; `}

        fun h_length: Int `{ return recv->h_length; `}

        fun h_name: String import NativeString.to_s `{ return NativeString_to_s(recv->h_name); `}
end

extern class NativeTimeval `{ struct timeval* `}
        new (seconds: Int, microseconds: Int) `{
                struct timeval* tv = NULL;
                tv = malloc(sizeof(struct timeval));
                tv->tv_sec = seconds;
                tv->tv_usec = microseconds;
                return tv;
        `}

        fun seconds: Int `{ return recv->tv_sec; `}

        fun microseconds: Int `{ return recv->tv_usec; `}

        fun destroy `{ free(recv); `}
end

extern class NativeSocketSet `{ fd_set* `}
        new `{
                fd_set *f = NULL;
                f = malloc(sizeof(fd_set));
                return f;
        `}

        fun set(s: NativeSocket) `{ FD_SET(*s, recv); `}

        fun is_set(s: NativeSocket): Bool `{ return FD_ISSET(*s, recv); `}

        fun zero `{ FD_ZERO(recv); `}

        fun clear(s: NativeSocket) `{ FD_CLR(*s, recv); `}

        fun destroy `{ free(recv); `}
end

class NativeSocketObserver
        # FIXME this implementation is broken. `reads`, `write` and `except`
        # are boxed objects, passing them to a C function is illegal.
        fun select(max: NativeSocket, reads: nullable NativeSocketSet, write: nullable NativeSocketSet,
                         except: nullable NativeSocketSet, timeout: NativeTimeval): Int `{
                fd_set *rds, *wts, *exs = NULL;
                struct timeval *tm = NULL;
                if (reads != NULL) rds = (fd_set*)reads;
                if (write != NULL) wts = (fd_set*)write;
                if (except != NULL) exs = (fd_set*)except;
                if (timeout != NULL) tm = (struct timeval*)timeout;
                return select(*max, rds, wts, exs, tm);
        `}
end

extern class NativeSocketTypes `{ int `}
        new sock_stream `{ return SOCK_STREAM; `}
        new sock_dgram `{ return SOCK_DGRAM; `}
        new sock_raw `{ return SOCK_RAW; `}
        new sock_seqpacket `{ return SOCK_SEQPACKET; `}
end

extern class NativeSocketAddressFamilies `{ int `}
        new af_null `{ return 0; `}

        # Unspecified
        new af_unspec `{ return AF_UNSPEC; `}

        # Local to host (pipes)
        new af_unix `{ return AF_UNIX; `}

        # For backward compatibility
        new af_local `{ return AF_LOCAL; `}

        # Internetwork: UDP, TCP, etc.
        new af_inet `{ return AF_INET; `}

        # IBM SNA
        new af_sna `{ return AF_SNA; `}

        # DECnet
        new af_decnet `{ return AF_DECnet; `}

        # Internal Routing Protocol
        new af_route `{ return AF_ROUTE; `}

        # Novell Internet Protocol
        new af_ipx `{ return AF_IPX; `}

        # Integrated Services Digital Network
        new af_isdn `{ return AF_ISDN; `}

        # IPv6
        new af_inet6 `{ return AF_INET6; `}

        new af_max `{ return AF_MAX; `}
end

extern class NativeSocketProtocolFamilies `{ int `}
        new pf_null `{ return 0; `}
        new pf_unspec `{ return PF_UNSPEC; `}
        new pf_local `{ return PF_LOCAL; `}
        new pf_unix `{ return PF_UNIX; `}
        new pf_inet `{ return PF_INET; `}
        new pf_sna `{ return PF_SNA; `}
        new pf_decnet `{ return PF_DECnet; `}
        new pf_route `{ return PF_ROUTE; `}
        new pf_ipx `{ return PF_IPX; `}
        new pf_isdn `{ return PF_ISDN; `}
        new pf_key `{ return PF_KEY; `}
        new pf_inet6 `{ return PF_INET6; `}
        new pf_max `{ return PF_MAX; `}
end

# Level on which to set options
extern class NativeSocketOptLevels `{ int `}

        # Dummy for IP (As defined in C)
        new ip `{ return IPPROTO_IP;`}

        # Control message protocol
        new icmp `{ return IPPROTO_ICMP;`}

        # Use TCP
        new tcp `{ return IPPROTO_TCP; `}

        # Socket level options
        new socket `{ return SOL_SOCKET; `}
end

# Options for socket, use with setsockopt
extern class NativeSocketOptNames `{ int `}

        # Enables debugging information
        new debug `{ return SO_DEBUG; `}

        # Authorizes the broadcasting of messages
        new broadcast `{ return SO_BROADCAST; `}

        # Authorizes the reuse of the local address
        new reuseaddr `{ return SO_REUSEADDR; `}

        # Authorizes the use of keep-alive packets in a connection
        new keepalive `{ return SO_KEEPALIVE; `}

        # Disable the Nagle algorithm and send data as soon as possible, in smaller packets
        new tcp_nodelay `{ return TCP_NODELAY; `}
end

# Used for the poll function of a socket, mix several Poll values to check for events on more than one type of event
extern class NativeSocketPollValues `{ int `}

        # Data other than high-priority data may be read without blocking.
        new pollin `{ return POLLIN; `}

        # Normal data may be read without blocking.
        new pollrdnorm `{ return POLLRDNORM; `}

        # Priority data may be read without blocking.
        new pollrdband `{ return POLLRDBAND; `}

        # High-priority data may be read without blocking.
        new pollpri `{ return POLLPRI; `}

        # Normal data may be written without blocking.
        new pollout `{ return POLLOUT; `}

        # Equivalent to POLLOUT
        new pollwrnorm `{ return POLLWRNORM; `}

        # Priority data may be written.
        new pollwrband `{ return POLLWRBAND; `}

        # An error has occurred on the device or stream.
        #
        # This flag is only valid in the revents bitmask; it shall be ignored in the events member.
        new pollerr `{ return POLLERR; `}

        # The device has been disconnected.
        #
        # This event and POLLOUT are mutually-exclusive; a stream can never be
        # writable if a hangup has occurred. However, this event and POLLIN,
        # POLLRDNORM, POLLRDBAND, or POLLPRI are not mutually-exclusive.
        #
        # This flag is only valid in the revents bitmask; it shall be ignored in the events member.
        new pollhup `{ return POLLHUP; `}

        # The specified fd value is invalid.
        #
        # This flag is only valid in the revents member; it shall ignored in the events member.
        new pollnval `{ return POLLNVAL; `}

        # Combines two NativeSocketPollValues
        private fun +(other: NativeSocketPollValues): NativeSocketPollValues `{
                return recv | other;
        `}
end