/* -*- c-basic-offset: 4; -*- */

/* sock.c: General Socket Functions

 *

 * Copyright (c) 1999 the icecast team

 *

 *  This library is free software; you can redistribute it and/or

 *  modify it under the terms of the GNU Library General Public

 *  License as published by the Free Software Foundation; either

 *  version 2 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

 *  Library General Public License for more details.

 *

 *  You should have received a copy of the GNU Library General Public

 *  License along with this library; if not, write to the Free

 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

 */

#ifdef HAVE_CONFIG_H

 #include <config.h>

#endif

#include <stdio.h>

#include <stdlib.h>

#include <stdarg.h>

#include <sys/types.h>

#include <ctype.h>

#include <string.h>

#include <fcntl.h>

#include <errno.h>

#ifdef HAVE_SYS_SELECT_H

#include <sys/select.h>

#endif

#ifndef _WIN32

#include <unistd.h>

#include <sys/socket.h>

#include <netinet/in.h>

#include <netinet/tcp.h>

#include <arpa/inet.h>

#include <sys/time.h>

#include <netdb.h>

#else

#include <winsock2.h>

#define vsnprintf _vsnprintf

#define EINPROGRESS WSAEINPROGRESS

#define ENOTSOCK WSAENOTSOCK

#define EWOULDBLOCK WSAEWOULDBLOCK

#define EALREADY WSAEALREADY

#define socklen_t    int

#ifndef __MINGW32__

#define va_copy(ap1, ap2) memcpy(&ap1, &ap2, sizeof(va_list))

#endif

#endif

#include "sock.h"

#include "resolver.h"

/* sock_initialize

**

** initializes the socket library.  you must call this

** before using the library!

*/

void sock_initialize(void)

{

#ifdef _WIN32

    WSADATA wsad;

    WSAStartup(0x0101, &wsad);

#endif

    resolver_initialize();

}

/* sock_shutdown

**

** shutdown the socket library.  remember to call this when you're

** through using the lib

*/

void sock_shutdown(void)

{

#ifdef _WIN32

    WSACleanup();

#endif

    resolver_shutdown();

}

/* sock_get_localip

**

** gets the local ip address for the machine

** the ip it returns *should* be on the internet.

** in any case, it's as close as we can hope to get

** unless someone has better ideas on how to do this

*/

char *sock_get_localip(char *buff, int len)

{

    char temp[1024];

    if (gethostname(temp, sizeof(temp)) != 0)

        return NULL;

    if (resolver_getip(temp, buff, len))

        return buff;

    return NULL;

}

/* sock_error

** 

** returns the last socket error

*/

int sock_error(void)

{

#ifdef _WIN32

    return WSAGetLastError();

#else

    return errno;

#endif

}

static void sock_set_error(int val)

{

#ifdef _WIN32

     WSASetLastError (val);

#else

     errno = val;

#endif

}

/* sock_recoverable

**

** determines if the socket error is recoverable

** in terms of non blocking sockets

*/

int sock_recoverable(int error)

{

    switch (error)

    {

    case 0:

    case EAGAIN:

    case EINTR:

    case EINPROGRESS:

#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN

    case EWOULDBLOCK:

#endif

#ifdef ERESTART

    case ERESTART:

#endif

        return 1;

    default:

        return 0;

    }

}

int sock_stalled (int error)

{

    switch (error)

    {

    case EAGAIN:

    case EINPROGRESS:

    case EALREADY:

#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN

    case EWOULDBLOCK:

#endif

#ifdef ERESTART

    case ERESTART:

#endif

        return 1;

    default:

        return 0;

    }

}

static int sock_connect_pending (int error)

{

    return error == EINPROGRESS || error == EALREADY;

}

/* sock_valid_socket

**

** determines if a sock_t represents a valid socket

*/

int sock_valid_socket(sock_t sock)

{

    int ret;

    int optval;

    socklen_t optlen;

    optlen = sizeof(int);

    /* apparently on windows getsockopt.optval is a char * */

    ret = getsockopt(sock, SOL_SOCKET, SO_TYPE, (void*) &optval, &optlen);

    return (ret == 0);

}

/* inet_aton

**

** turns an ascii ip address into a binary representation

*/

#ifdef _WIN32

int inet_aton(const char *s, struct in_addr *a)

{

    int lsb, b2, b3, msb;

    if (sscanf(s, "%d.%d.%d.%d", &lsb, &b2, &b3, &msb) < 4) {

        return 0;

    }

    a->s_addr = inet_addr(s);

    return (a->s_addr != INADDR_NONE);

}

#endif /* _WIN32 */

/* sock_set_blocking

**

** set the sock blocking or nonblocking

** SOCK_BLOCK for blocking

** SOCK_NONBLOCK for nonblocking

*/

int sock_set_blocking(sock_t sock, const int block)

{

#ifdef _WIN32

#ifdef __MINGW32__

    u_long varblock = block;

#else

    int varblock = block;

#endif

#endif

    if ((!sock_valid_socket(sock)) || (block < 0) || (block > 1))

        return SOCK_ERROR;

#ifdef _WIN32

    return ioctlsocket(sock, FIONBIO, &varblock);

#else

    return fcntl(sock, F_SETFL, (block == SOCK_BLOCK) ? 0 : O_NONBLOCK);

#endif

}

int sock_set_nolinger(sock_t sock)

{

    struct linger lin = { 0, 0 };

    return setsockopt(sock, SOL_SOCKET, SO_LINGER, (void *)&lin, 

            sizeof(struct linger));

}

int sock_set_nodelay(sock_t sock)

{

    int nodelay = 1;

    return setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, (void *)&nodelay,

            sizeof(int));

}

int sock_set_keepalive(sock_t sock)

{

    int keepalive = 1;

    return setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE, (void *)&keepalive, 

            sizeof(int));

}

/* sock_close

**

** close the socket

*/

int sock_close(sock_t sock)

{

#ifdef _WIN32

    return closesocket(sock);

#else

    return close(sock);

#endif

}

/* sock_writev

 *

 * write multiple buffers at once, return bytes actually written

 */

#ifdef HAVE_WRITEV

ssize_t sock_writev (int sock, const struct iovec *iov, const size_t count)

{

    return writev (sock, iov, count);

}

#else

ssize_t sock_writev (int sock, const struct iovec *iov, const size_t count)

{

    int i = count, accum = 0, ret;

    const struct iovec *v = iov;

    while (i)

    {

        if (v->iov_base && v->iov_len)

        {

            ret = sock_write_bytes (sock, v->iov_base, v->iov_len);

            if (ret == -1 && accum==0)

                return -1;

            if (ret == -1)

                ret = 0;

            accum += ret;

            if (ret < (int)v->iov_len)

                break;

        }

        v++;

        i--;

    }

    return accum;

}

#endif

/* sock_write_bytes

**

** write bytes to the socket

** this function will _NOT_ block

*/

int sock_write_bytes(sock_t sock, const void *buff, const size_t len)

{

    /* sanity check */

    if (!buff) {

        return SOCK_ERROR;

    } else if (len <= 0) {

        return SOCK_ERROR;

    } /*else if (!sock_valid_socket(sock)) {

        return SOCK_ERROR;

    } */

    return send(sock, buff, len, 0);

}

/* sock_write_string

**

** writes a string to a socket

** This function must only be called with a blocking socket.

*/

int sock_write_string(sock_t sock, const char *buff)

{

    return (sock_write_bytes(sock, buff, strlen(buff)) > 0);

}

/* sock_write

**

** write a formatted string to the socket

** this function must only be called with a blocking socket.

** will truncate the string if it's greater than 1024 chars.

*/

int sock_write(sock_t sock, const char *fmt, ...)

{

    int rc;

    va_list ap;

    va_start (ap, fmt);

    rc = sock_write_fmt (sock, fmt, ap);

    va_end (ap);

    return rc;

}

#ifdef HAVE_OLD_VSNPRINTF

int sock_write_fmt(sock_t sock, const char *fmt, va_list ap)

{

    va_list ap_local;

    unsigned int len = 1024;

    char *buff = NULL;

    int ret;

    /* don't go infinite, but stop at some huge limit */

    while (len < 2*1024*1024)

    {

        char *tmp = realloc (buff, len);

        ret = -1;

        if (tmp == NULL)

            break;

        buff = tmp;

        va_copy (ap_local, ap);

        ret = vsnprintf (buff, len, fmt, ap_local);

        if (ret > 0)

        {

            ret = sock_write_bytes (sock, buff, ret);

            break;

        }

        len += 8192;

    }

    free (buff);

    return ret;

}

#else

int sock_write_fmt(sock_t sock, const char *fmt, va_list ap)

{

    char buffer [1024], *buff = buffer;

    int len;

    int rc = SOCK_ERROR;

    va_list ap_retry;

    va_copy (ap_retry, ap);

    len = vsnprintf (buff, sizeof (buffer), fmt, ap);

    if (len > 0)

    {

        if ((size_t)len < sizeof (buffer))   /* common case */

            rc = sock_write_bytes(sock, buff, (size_t)len);

        else

        {

            /* truncated */

            buff = malloc (++len);

            if (buff)

            {

                len = vsnprintf (buff, len, fmt, ap_retry);

                if (len > 0)

                    rc = sock_write_bytes (sock, buff, len);

                free (buff);

            }

        }

    }

    va_end (ap_retry);

    return rc;

}

#endif

int sock_read_bytes(sock_t sock, char *buff, const int len)

{

    /*if (!sock_valid_socket(sock)) return 0; */

    if (!buff) return 0;

    if (len <= 0) return 0;

    return recv(sock, buff, len, 0);

}

/* sock_read_line

**

** Read one line of at max len bytes from sock into buff.

** If ok, return 1 and nullterminate buff. Otherwize return 0.

** Terminating \n is not put into the buffer.

**

** this function will probably not work on sockets in nonblocking mode

*/

int sock_read_line(sock_t sock, char *buff, const int len)

{

    char c = '\0';

    int read_bytes, pos;

    /*if (!sock_valid_socket(sock)) {

        return 0;

    } else*/ if (!buff) {

        return 0;

    } else if (len <= 0) {

        return 0;

    }

    pos = 0;

    read_bytes = recv(sock, &c, 1, 0);

    if (read_bytes < 0) {

        return 0;

    }

    while ((c != '\n') && (pos < len) && (read_bytes == 1)) {

        if (c != '\r')

            buff[pos++] = c;

        read_bytes = recv(sock, &c, 1, 0);

    }

    if (read_bytes == 1) {

        buff[pos] = '\0';

        return 1;

    } else {

        return 0;

    }

}

/* see if a connection has been established. If timeout is < 0 then wait

 * indefinitely, else wait for the stated number of seconds.

 * return SOCK_TIMEOUT for timeout

 * return SOCK_ERROR for failure

 * return 0 for try again, interrupted

 * return 1 for ok 

 */

int sock_connected (int sock, int timeout)

{

    fd_set wfds;

    int val = SOCK_ERROR;

    socklen_t size = sizeof val;

    struct timeval tv, *timeval = NULL;

    /* make a timeout of <0 be indefinite */

    if (timeout >= 0)

    {

        tv.tv_sec = timeout;

        tv.tv_usec = 0;

        timeval = &tv;

    }

    FD_ZERO(&wfds);

    FD_SET(sock, &wfds);

    switch (select(sock + 1, NULL, &wfds, NULL, timeval))

    {

        case 0:

            return SOCK_TIMEOUT;

        default:

            /* on windows getsockopt.val is defined as char* */

            if (getsockopt(sock, SOL_SOCKET, SO_ERROR, (void*) &val, &size) == 0)

            {

                if (val == 0)

                    return 1;

                sock_set_error (val);

            }

            /* fall through */

        case -1:

            if (sock_recoverable (sock_error()))

                return 0;

            return SOCK_ERROR;

    }

}

#ifdef HAVE_GETADDRINFO

int sock_connect_non_blocking (const char *hostname, const unsigned port)

{

    int sock = SOCK_ERROR;

    struct addrinfo *ai, *head, hints;

    char service[8];

    memset (&hints, 0, sizeof (hints));

    hints.ai_family = AF_UNSPEC;

    hints.ai_socktype = SOCK_STREAM;

    snprintf (service, sizeof (service), "%u", port);

    if (getaddrinfo (hostname, service, &hints, &head))

        return SOCK_ERROR;

    ai = head;

    while (ai)

    {

        if ((sock = socket (ai->ai_family, ai->ai_socktype, ai->ai_protocol)) 

                > -1)

        {

            sock_set_blocking (sock, SOCK_NONBLOCK);

            if (connect(sock, ai->ai_addr, ai->ai_addrlen) < 0 && 

                    !sock_connect_pending(sock_error()))

            {

                sock_close (sock);

                sock = SOCK_ERROR;

            }

            else

                break;

        }

        ai = ai->ai_next;

    }

    if (head) freeaddrinfo (head);

    return sock;

}

/* issue a connect, but return after the timeout (seconds) is reached. If

 * timeout is 0 or less then we will wait until the OS gives up on the connect

 * The socket is returned

 */

sock_t sock_connect_wto(const char *hostname, int port, int timeout)

{

    int sock = SOCK_ERROR;

    struct addrinfo *ai, *head, hints;

    char service[8];

    memset (&hints, 0, sizeof (hints));

    hints.ai_family = AF_UNSPEC;

    hints.ai_socktype = SOCK_STREAM;

    snprintf (service, sizeof (service), "%u", port);

    if (getaddrinfo (hostname, service, &hints, &head))

        return SOCK_ERROR;

    ai = head;

    while (ai)

    {

        if ((sock = socket (ai->ai_family, ai->ai_socktype, ai->ai_protocol)) >= 0)

        {

            if (timeout > 0)

                sock_set_blocking (sock, SOCK_NONBLOCK);

            if (connect (sock, ai->ai_addr, ai->ai_addrlen) == 0)

                break;

            /* loop as the connect maybe async */

            while (sock != SOCK_ERROR)

            {

                if (sock_recoverable (sock_error()))

                {

                    int connected = sock_connected (sock, timeout);

                    if (connected == 0)  /* try again, interrupted */

                        continue;

                    if (connected == 1) /* connected */

                    {

                        if (timeout >= 0)

                            sock_set_blocking(sock, SOCK_BLOCK);

                        break;

                    }

                }

                sock_close (sock);

                sock = SOCK_ERROR;

            }

            if (sock != SOCK_ERROR)

                break;

        }

        ai = ai->ai_next;

    }

    if (head)

        freeaddrinfo (head);

    return sock;

}

#else

int sock_try_connection (int sock, const char *hostname, const unsigned port)

{

    struct sockaddr_in sin, server;

    char ip[MAX_ADDR_LEN];

    if (!hostname || !hostname[0] || port == 0)

        return -1;

    memset(&sin, 0, sizeof(struct sockaddr_in));

    memset(&server, 0, sizeof(struct sockaddr_in));

    if (!resolver_getip(hostname, ip, MAX_ADDR_LEN))

    {

        sock_close (sock);

        return -1;

    }

    if (inet_aton(ip, (struct in_addr *)&sin.sin_addr) == 0)

    {

        sock_close(sock);

        return -1;

    }

    memcpy(&server.sin_addr, &sin.sin_addr, sizeof(struct sockaddr_in));

    server.sin_family = AF_INET;

    server.sin_port = htons(port);

    return connect(sock, (struct sockaddr *)&server, sizeof(server));

}

int sock_connect_non_blocking (const char *hostname, const unsigned port)

{

    int sock;

    sock = socket(AF_INET, SOCK_STREAM, 0);

    if (sock == -1)

        return -1;

    sock_set_blocking (sock, SOCK_NONBLOCK);

    sock_try_connection (sock, hostname, port);

    return sock;

}

sock_t sock_connect_wto(const char *hostname, const int port, const int timeout)

{

    int sock;

    sock = socket(AF_INET, SOCK_STREAM, 0);

    if (sock == -1)

        return -1;

    if (timeout)

    {

        sock_set_blocking (sock, SOCK_NONBLOCK);

        if (sock_try_connection (sock, hostname, port) < 0)

        {

            int ret = sock_connected (sock, timeout);

            if (ret <= 0)

            {

                sock_close (sock);

                return SOCK_ERROR;

            }

        }

        sock_set_blocking(sock, SOCK_BLOCK);

    }

    else

    {

        if (sock_try_connection (sock, hostname, port) < 0)

        {

            sock_close (sock);

            sock = SOCK_ERROR;

        }

    }

    return sock;

}

#endif

/* sock_get_server_socket

**

** create a socket for incoming requests on a specified port and

** interface.  if interface is null, listen on all interfaces.

** returns the socket, or SOCK_ERROR on failure

*/

sock_t sock_get_server_socket(const int port, char *sinterface)

{

#ifdef HAVE_INET_PTON

    struct sockaddr_storage sa;

#else    

    struct sockaddr_in sa;

#endif

    int family, len, error, opt;

    sock_t sock;

    char ip[MAX_ADDR_LEN];

    if (port < 0)

        return SOCK_ERROR;

    /* defaults */

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

    family = AF_INET;

    len = sizeof(struct sockaddr_in);

    /* set the interface to bind to if specified */

    if (sinterface != NULL) {

        if (!resolver_getip(sinterface, ip, sizeof (ip)))

            return SOCK_ERROR;

#ifdef HAVE_INET_PTON

        if (inet_pton(AF_INET, ip, &((struct sockaddr_in*)&sa)->sin_addr) > 0) {

            ((struct sockaddr_in*)&sa)->sin_family = AF_INET;

            ((struct sockaddr_in*)&sa)->sin_port = htons(port);

        } else if (inet_pton(AF_INET6, ip, 

                    &((struct sockaddr_in6*)&sa)->sin6_addr) > 0) {

            family = AF_INET6;

            len = sizeof (struct sockaddr_in6);

            ((struct sockaddr_in6*)&sa)->sin6_family = AF_INET6;

            ((struct sockaddr_in6*)&sa)->sin6_port = htons(port);

        } else {

            return SOCK_ERROR;

        }

#else

        if (!inet_aton(ip, &sa.sin_addr)) {

            return SOCK_ERROR;

        } else {

            sa.sin_family = AF_INET;

            sa.sin_port = htons(port);

        }

#endif

    } else {

        ((struct sockaddr_in*)&sa)->sin_addr.s_addr = INADDR_ANY;

        ((struct sockaddr_in*)&sa)->sin_family = AF_INET;

        ((struct sockaddr_in*)&sa)->sin_port = htons(port);

    }

    /* get a socket */

    sock = socket(family, SOCK_STREAM, 0);

    if (sock == -1)

        return SOCK_ERROR;

    /* reuse it if we can */

    opt = 1;

    setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (const void *)&opt, sizeof(int));

    /* bind socket to port */

    error = bind(sock, (struct sockaddr *)&sa, len);

    if (error == -1)

        return SOCK_ERROR;

    return sock;

}

int sock_listen(sock_t serversock, int backlog)

{

    if (!sock_valid_socket(serversock))

        return 0;

    if (backlog <= 0)

        backlog = 10;

    return (listen(serversock, backlog) == 0);

}

int sock_accept(sock_t serversock, char *ip, int len)

{

#ifdef HAVE_INET_PTON

    struct sockaddr_storage sa;

#else    

    struct sockaddr_in sa;

#endif

    int ret;

    socklen_t slen;

    if (!sock_valid_socket(serversock))

        return SOCK_ERROR;

    slen = sizeof(sa);

    ret = accept(serversock, (struct sockaddr *)&sa, &slen);

    if (ret >= 0 && ip != NULL) {

#ifdef HAVE_INET_PTON

        if(((struct sockaddr_in *)&sa)->sin_family == AF_INET) 

            inet_ntop(AF_INET, &((struct sockaddr_in *)&sa)->sin_addr,

                    ip, len);

        else if(((struct sockaddr_in6 *)&sa)->sin6_family == AF_INET6) 

            inet_ntop(AF_INET6, &((struct sockaddr_in6 *)&sa)->sin6_addr, 

                    ip, len);

        else {

            strncpy(ip, "ERROR", len-1);

            ip[len-1] = 0;

        }

#else

        /* inet_ntoa is not reentrant, we should protect this */

        strncpy(ip, inet_ntoa(sa.sin_addr), len);

#endif

        sock_set_nolinger(ret);

        sock_set_keepalive(ret);

    }

    return ret;

}