/*
 * Socket interface API
 */
#include <netdb.h>              /* getaddrinfo() */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/socket.h>

#include "nvt_log.h"
#include "nvt_socket.h"


typedef struct {
    unsigned short  type;       // socket type
    unsigned short  slen;       // sockaddr length
    union {
        struct sockaddr gen;
        struct sockaddr_in ipv4;
    };
} sa_t;


static int _sa_host_lookup(sa_t * sa, const char *host)
{
    struct hostent *server;

    server = gethostbyname(host);
    if (server == NULL)
    {
        nvt_log(LOG_ERR, "Cannot resolve host name: %m\n");
        return -1;
    }

    sa->slen = sizeof(sa->ipv4);

    sa->ipv4.sin_family = AF_INET;
    memcpy(&sa->ipv4.sin_addr.s_addr, server->h_addr, server->h_length);

    return 0;
}

static int _sa_addr_parse(sa_t * sa, const char *addr)
{
    char            host[64], port[64];

    memset(sa, 0, sizeof(sa_t));

    sscanf(addr, "%63[^:]:%63s", host, port);

    if (_sa_host_lookup(sa, host) != 0)
        return -1;

    sa->type = SOCK_STREAM;
    sa->ipv4.sin_port = htons(atoi(port));

    return 0;
}

int socket_create_client(const char *addr)
{
    sa_t            sa;
    int             fd, err;

    if (_sa_addr_parse(&sa, addr) != 0)
        return -1;

    fd = socket(sa.gen.sa_family, sa.type, 0);
    if (fd < 0)
    {
        nvt_log(LOG_ERR, "%s: Could not find address: '%s'", __func__, addr);
        return fd;
    }

    err = connect(fd, &sa.gen, sa.slen);
    if (err < 0)
    {
        nvt_log(LOG_ERR, "Failed to connect to: %s: %m\n", addr);
        close(fd);
        return -1;
    }

    return fd;
}

int socket_create_server(const char *addr)
{
    sa_t            sa;
    int             err, fd, opt;

    err = _sa_addr_parse(&sa, addr);
    if (err != 0)
    {
        nvt_log(LOG_ERR, "%s: Could not find address: '%s'", __func__, addr);
        return -1;
    }

    fd = socket(sa.gen.sa_family, sa.type, 0);
    if (fd < 0)
    {
        nvt_log(LOG_ERR, "%s: *** socket(%s): %m", __func__, addr);
        return -1;
    }

    if (sa.gen.sa_family == AF_INET)
    {
        /* Avoid TIME_WAIT state on socket close */
        opt = 1;
        setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
    }

    err = bind(fd, &sa.gen, sa.slen);
    if (err != 0)
    {
        nvt_log(LOG_ERR, "%s: *** bind(%s): %m", __func__, addr);
        close(fd);
        return -1;
    }

    if (sa.type == SOCK_STREAM)
    {
        err = listen(fd, 5);
        if (err != 0)
        {
            nvt_log(LOG_ERR, "%s: *** listen(%s): %m", __func__, addr);
            close(fd);
            return -1;
        }
    }

    return fd;
}

int socket_create_server_client(int sfd)
{
    int             cfd;
    socklen_t       slen;

    slen = 0;
    cfd = accept(sfd, NULL, &slen);
    if (cfd < 0)
    {
        nvt_log(LOG_ERR, "%s: *** accept(): %m", __func__);
        return -1;
    }

    return cfd;
}