/* anet.c -- Basic TCP socket stuff
 * Copyright (C) 2006,2007 Salvatore Sanfilippo, antirez@gmail.com
 * This softare is released under the following BSD license:
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions 
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the author nor the names of its contributors may 
 *    be used to endorse or promote products derived from this software 
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL COPYRIGHT HOLDER BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <fcntl.h>
#include <string.h>
#include <netdb.h>
#include <errno.h>
#include <stdarg.h>
#include <stdio.h>

#include "anet.h"

static void anetSetError(char *err, const char *fmt, ...)
{
    va_list ap;

    if (!err) return;
    va_start(ap, fmt);
    vsnprintf(err, ANET_ERR_LEN, fmt, ap);
    va_end(ap);
}

int anetNonBlock(char *err, int fd)
{
    int flags;

    /* Set the socket nonblocking.
     * Note that fcntl(2) for F_GETFL and F_SETFL can't be
     * interrupted by a signal. */
    if ((flags = fcntl(fd, F_GETFL)) == -1) {
        anetSetError(err, "fcntl(F_GETFL): %s\n", strerror(errno));
        return ANET_ERR;
    }
    if (fcntl(fd, F_SETFL, flags | O_NONBLOCK) == -1) {
        anetSetError(err, "fcntl(F_SETFL,O_NONBLOCK): %s\n", strerror(errno));
        return ANET_ERR;
    }
    return ANET_OK;
}

int anetTcpNoDelay(char *err, int fd)
{
    int buffsize = 1024*8;
    if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &buffsize, sizeof(buffsize)) == -1)
    {
        anetSetError(err, "setsockopt SO_SNDBUF: %s\n", strerror(errno));
        return ANET_ERR;
    }
    return ANET_OK;
}

int anetResolve(char *err, char *host, char *ipbuf)
{
    struct sockaddr_in sa;

    sa.sin_family = AF_INET;
    if (inet_aton(host, &sa.sin_addr) == 0) {
        struct hostent *he;

        he = gethostbyname(host);
        if (he == NULL) {
            anetSetError(err, "can't resolve: %s\n", host);
            return ANET_ERR;
        }
        memcpy(&sa.sin_addr, he->h_addr, sizeof(struct in_addr));
    }
    strcpy(ipbuf,inet_ntoa(sa.sin_addr));
    return ANET_OK;
}

int anetTcpConnect(char *err, char *addr, int port)
{
    int s;
    struct sockaddr_in sa;

    if ((s = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
        anetSetError(err, "creating socket: %s\n", strerror(errno));
        return ANET_ERR;
    }
    sa.sin_family = AF_INET;
    sa.sin_port = htons(port);
    if (inet_aton(addr, &sa.sin_addr) == 0) {
        struct hostent *he;

        he = gethostbyname(addr);
        if (he == NULL) {
            anetSetError(err, "can't resolve: %s\n", addr);
            close(s);
            return ANET_ERR;
        }
        memcpy(&sa.sin_addr, he->h_addr, sizeof(struct in_addr));
    }
    if (connect(s, (struct sockaddr*)&sa, sizeof(sa)) == -1) {
        anetSetError(err, "connect: %s\n", strerror(errno));
        close(s);
        return ANET_ERR;
    }
    return s;
}

/* Like read(2) but make sure 'count' is read before to return
 * (unless error or EOF condition is encountered) */
int anetRead(int fd, void *buf, int count)
{
    int nread, totlen = 0;
    while(totlen != count) {
        nread = read(fd,buf,count-totlen);
        if (nread == 0) return totlen;
        if (nread == -1) return -1;
        totlen += nread;
        buf += nread;
    }
    return totlen;
}

/* Like write(2) but make sure 'count' is read before to return
 * (unless error is encountered) */
int anetWrite(int fd, void *buf, int count)
{
    int nwritten, totlen = 0;
    while(totlen != count) {
        nwritten = write(fd,buf,count-totlen);
        if (nwritten == 0) return totlen;
        if (nwritten == -1) return -1;
        totlen += nwritten;
        buf += nwritten;
    }
    return totlen;
}

int anetTcpServer(char *err, int port, char *bindaddr)
{
    int s, on = 1;
    struct sockaddr_in sa;
    
    if ((s = socket(AF_INET, SOCK_STREAM, 0)) == -1) {
        anetSetError(err, "socket: %s\n", strerror(errno));
        return ANET_ERR;
    }
    if (setsockopt(s, SOL_SOCKET, SO_REUSEADDR, &on, sizeof(on)) == -1) {
        anetSetError(err, "setsockopt SO_REUSEADDR: %s\n", strerror(errno));
        close(s);
        return ANET_ERR;
    }
    sa.sin_family = AF_INET;
    sa.sin_port = htons(port);
    sa.sin_addr.s_addr = htonl(INADDR_ANY);
    if (bindaddr) inet_aton(bindaddr, &sa.sin_addr);

    if (bind(s, (struct sockaddr*)&sa, sizeof(sa)) == -1) {
        anetSetError(err, "bind: %s\n", strerror(errno));
        close(s);
        return ANET_ERR;
    }
    if (listen(s, 5) == -1) {
        anetSetError(err, "listen: %s\n", strerror(errno));
        close(s);
        return ANET_ERR;
    }
    return s;
}

int anetAccept(char *err, int serversock, char *ip, int *port)
{
    int fd;
    struct sockaddr_in sa;
    unsigned int saLen;

    while(1) {
        saLen = sizeof(sa);
        fd = accept(serversock, (struct sockaddr*)&sa, &saLen);
        if (fd == -1) {
            if (errno == EINTR)
                continue;
            else {
                anetSetError(err, "accept: %s\n", strerror(errno));
                return ANET_ERR;
            }
        }
        break;
    }
    if (ip) strcpy(ip,inet_ntoa(sa.sin_addr));
    if (port) *port = ntohs(sa.sin_port);
    return fd;
}