/*
 * socket.c
 *
 * Copyright (c) 2012 Martin Szulecki All Rights Reserved.
 * Copyright (c) 2012 Nikias Bassen All Rights Reserved.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA 
 */

#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>
#include <sys/stat.h>
#ifdef WIN32
#include <winsock2.h>
#include <windows.h>
static int wsa_init = 0;
#else
#include <sys/socket.h>
#include <sys/un.h>
#include <netinet/in.h>
#include <netdb.h>
#include <arpa/inet.h>
#endif
#include "socket.h"

#define RECV_TIMEOUT 20000

static int verbose = 0;

void socket_set_verbose(int level)
{
    verbose = level;
}

#ifndef WIN32
int socket_create_unix(const char *filename)
{
    struct sockaddr_un name;
    int sock;
    size_t size;

    // remove if still present
    unlink(filename);

    /* Create the socket. */
    sock = socket(PF_LOCAL, SOCK_STREAM, 0);
    if (sock < 0) {
        perror("socket");
        return -1;
    }

    /* Bind a name to the socket. */
    name.sun_family = AF_LOCAL;
    strncpy(name.sun_path, filename, sizeof(name.sun_path));
    name.sun_path[sizeof(name.sun_path) - 1] = '\0';

    /* The size of the address is
       the offset of the start of the filename,
       plus its length,
       plus one for the terminating null byte.
       Alternatively you can just do:
       size = SUN_LEN (&name);
     */
    size = (offsetof(struct sockaddr_un, sun_path)
            + strlen(name.sun_path) + 1);

    if (bind(sock, (struct sockaddr *) &name, size) < 0) {
        perror("bind");
        socket_close(sock);
        return -1;
    }

    if (listen(sock, 10) < 0) {
        perror("listen");
        socket_close(sock);
        return -1;
    }

    return sock;
}

int socket_connect_unix(const char *filename)
{
    struct sockaddr_un name;
    int sfd = -1;
    size_t size;
    struct stat fst;

    // check if socket file exists...
    if (stat(filename, &fst) != 0) {
        if (verbose >= 2)
            fprintf(stderr, "%s: stat '%s': %s\n", __func__, filename,
                    strerror(errno));
        return -1;
    }
    // ... and if it is a unix domain socket
    if (!S_ISSOCK(fst.st_mode)) {
        if (verbose >= 2)
            fprintf(stderr, "%s: File '%s' is not a socket!\n", __func__,
                    filename);
        return -1;
    }
    // make a new socket
    if ((sfd = socket(PF_LOCAL, SOCK_STREAM, 0)) < 0) {
        if (verbose >= 2)
            fprintf(stderr, "%s: socket: %s\n", __func__, strerror(errno));
        return -1;
    }
    // and connect to 'filename'
    name.sun_family = AF_LOCAL;
    strncpy(name.sun_path, filename, sizeof(name.sun_path));
    name.sun_path[sizeof(name.sun_path) - 1] = 0;

    size = (offsetof(struct sockaddr_un, sun_path)
            + strlen(name.sun_path) + 1);

    if (connect(sfd, (struct sockaddr *) &name, size) < 0) {
        socket_close(sfd);
        if (verbose >= 2)
            fprintf(stderr, "%s: connect: %s\n", __func__,
                    strerror(errno));
        return -1;
    }

    return sfd;
}
#endif

int socket_create(uint16_t port)
{
    return socket_create(port, false);
}

int socket_create(uint16_t port, int nonblocking)
{
    int sfd = -1;
    int yes = 1;
#ifdef WIN32
    WSADATA wsa_data;
    if (!wsa_init) {
        if (WSAStartup(MAKEWORD(2,2), &wsa_data) != ERROR_SUCCESS) {
            fprintf(stderr, "WSAStartup failed!\n");
            ExitProcess(-1);
        }
        wsa_init = 1;
    }
#endif
    struct sockaddr_in saddr;

    if (0 > (sfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP))) {
        perror("socket()");
        return -1;
    }

    if (setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, (const char *)(void*)&yes, sizeof(int)) == -1) {
        perror("setsockopt()");
        socket_close(sfd);
        return -1;
    }

    if(nonblocking) {
        u_long iMode = 1;
        if(ioctlsocket(sfd, FIONBIO, &iMode) != 0) {
            perror("ioctlsocket()");
            socket_close(sfd);
            return -1;
        }
    }

    memset((void *) &saddr, 0, sizeof(saddr));
    saddr.sin_family = AF_INET;
    saddr.sin_addr.s_addr = htonl(INADDR_ANY);
    saddr.sin_port = htons(port);

    if (0 > bind(sfd, (struct sockaddr *) &saddr, sizeof(saddr))) {
        perror("bind()");
        socket_close(sfd);
        return -1;
    }

    if (listen(sfd, 1) == -1) {
        perror("listen()");
        socket_close(sfd);
        return -1;
    }

    return sfd;
}

int socket_connect(const char *addr, uint16_t port)
{
    int sfd = -1;
    int yes = 1;
    struct hostent *hp;
    struct sockaddr_in saddr;
#ifdef WIN32
    WSADATA wsa_data;
    if (!wsa_init) {
        if (WSAStartup(MAKEWORD(2,2), &wsa_data) != ERROR_SUCCESS) {
            fprintf(stderr, "WSAStartup failed!\n");
            ExitProcess(-1);
        }
        wsa_init = 1;
    }
#endif

    if (!addr) {
        errno = EINVAL;
        return -1;
    }

    if ((hp = gethostbyname(addr)) == NULL) {
        if (verbose >= 2)
            fprintf(stderr, "%s: unknown host '%s'\n", __FUNCTION__, addr);
        return -1;
    }

    if (!hp->h_addr) {
        if (verbose >= 2)
            fprintf(stderr, "%s: gethostbyname returned NULL address!\n",
                    __FUNCTION__);
        return -1;
    }

    if (0 > (sfd = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP))) {
        perror("socket()");
        return -1;
    }

    if (setsockopt(sfd, SOL_SOCKET, SO_REUSEADDR, (const char *)(void*)&yes, sizeof(int)) == -1) {
        perror("setsockopt()");
        socket_close(sfd);
        return -1;
    }

    memset((void *) &saddr, 0, sizeof(saddr));
    saddr.sin_family = AF_INET;
    saddr.sin_addr.s_addr = *(uint32_t *) hp->h_addr;
    saddr.sin_port = htons(port);

    if (connect(sfd, (struct sockaddr *) &saddr, sizeof(saddr)) < 0) {
        perror("connect");
        socket_close(sfd);
        return -2;
    }

    return sfd;
}

int socket_check_fd(int fd, fd_mode fdm, unsigned int timeout)
{
    fd_set fds;
    int sret;
    int eagain;
    struct timeval to;
    struct timeval *pto;

    if (fd <= 0) {
        if (verbose >= 2)
            fprintf(stderr, "ERROR: invalid fd in check_fd %d\n", fd);
        return -1;
    }

    FD_ZERO(&fds);
    FD_SET(fd, &fds);

    if (timeout > 0) {
        to.tv_sec = (time_t) (timeout / 1000);
        to.tv_usec = (time_t) ((timeout - (to.tv_sec * 1000)) * 1000);
        pto = &to;
    } else {
        pto = NULL;
    }

    sret = -1;

    do {
        eagain = 0;
        switch (fdm) {
        case FDM_READ:
            sret = select(fd + 1, &fds, NULL, NULL, pto);
            break;
        case FDM_WRITE:
            sret = select(fd + 1, NULL, &fds, NULL, pto);
            break;
        case FDM_EXCEPT:
            sret = select(fd + 1, NULL, NULL, &fds, pto);
            break;
        default:
            return -1;
        }

        if (sret < 0) {
            switch (errno) {
            case EINTR:
                // interrupt signal in select
                if (verbose >= 2)
                    fprintf(stderr, "%s: EINTR\n", __FUNCTION__);
                eagain = 1;
                break;
            case EAGAIN:
                if (verbose >= 2)
                    fprintf(stderr, "%s: EAGAIN\n", __FUNCTION__);
                break;
            default:
                if (verbose >= 2)
                    fprintf(stderr, "%s: select failed: %s\n", __FUNCTION__,
                            strerror(errno));
                return -1;
            }
        }
    } while (eagain);

    return sret;
}

int socket_accept(int fd, uint16_t port)
{
#ifdef WIN32
    int addr_len;
#else
    socklen_t addr_len;
#endif
    int result;
    struct sockaddr_in addr;

    memset(&addr, 0, sizeof(addr));
    addr.sin_family = AF_INET;
    addr.sin_addr.s_addr = htonl(INADDR_ANY);
    addr.sin_port = htons(port);

    addr_len = sizeof(addr);
    result = accept(fd, (struct sockaddr*)&addr, &addr_len);

    return result;
}

int socket_shutdown(int fd, int how)
{
    return shutdown(fd, how);
}

int socket_close(int fd) {
#ifdef WIN32
    return closesocket(fd);
#else
    return close(fd);
#endif
}

int socket_receive(int fd, void *data, size_t length)
{
    return socket_receive_timeout(fd, data, length, 0, RECV_TIMEOUT);
}

int socket_peek(int fd, void *data, size_t length)
{
    return socket_receive_timeout(fd, data, length, MSG_PEEK, RECV_TIMEOUT);
}

int socket_receive_timeout(int fd, void *data, size_t length, int flags,
                     unsigned int timeout)
{
    int res;
    int result;

    // check if data is available
    res = socket_check_fd(fd, FDM_READ, timeout);
    if (res <= 0) {
        return res;
    }
    // if we get here, there _is_ data available
    result = recv(fd, (char *)data, length, flags);
    if (res > 0 && result == 0) {
        // but this is an error condition
        if (verbose >= 3)
            fprintf(stderr, "%s: fd=%d recv returned 0\n", __FUNCTION__, fd);
        return -EAGAIN;
    }
    if (result < 0) {
        return -errno;
    }
    return result;
}

int socket_send(int fd, void *data, size_t length)
{
    return send(fd, (char *)data, length, 0);
}
