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icecast-common/net/sock.c

992 lines
23 KiB
C

/* -*- c-basic-offset: 4; -*- */
/* sock.c: General Socket Functions
*
* Copyright (C) 2014 Michael Smith <msmith@icecast.org>,
* Brendan Cully <brendan@xiph.org>,
* Karl Heyes <karl@xiph.org>,
* Jack Moffitt <jack@icecast.org>,
* Ed "oddsock" Zaleski <oddsock@xiph.org>,
* Copyright (C) 2014-2019 Philipp "ph3-der-loewe" Schafft <lion@lion.leolix.org>
*
* 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 Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, 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_POLL
#include <poll.h>
#endif
#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>
#endif
#ifdef HAVE_WINSOCK2_H
#include <winsock2.h>
#endif
#ifdef HAVE_WS2TCPIP_H
#include <ws2tcpip.h>
#endif
#include "sock.h"
#include "resolver.h"
/* for older C libraries */
#ifndef AI_NUMERICSERV
# define AI_NUMERICSERV 0
#endif
#ifndef AI_ADDRCONFIG
# define AI_ADDRCONFIG 0
#endif
/* 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_error
**
** returns the last socket error
*/
int sock_error(void)
{
#ifdef _WIN32
return WSAGetLastError();
#else
return errno;
#endif
}
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
#if defined (WSAEWOULDBLOCK) && WSAEWOULDBLOCK != EWOULDBLOCK
case WSAEWOULDBLOCK:
#endif
#if defined (WSAEINPROGRESS) && WSAEINPROGRESS != EINPROGRESS
case WSAEINPROGRESS:
#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);
}
/* determines if the passed socket is still connected */
int sock_active (sock_t sock)
{
char c;
int l;
l = recv (sock, &c, 1, MSG_PEEK);
if (l == 0)
return 0;
if (l == SOCK_ERROR && sock_recoverable (sock_error()))
return 1;
return 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
* 1 for blocking
* 0 for nonblocking
*/
int sock_set_blocking(sock_t sock, int block)
{
#ifdef _WIN32
#ifdef __MINGW32__
u_long varblock = 1;
#else
int varblock = 1;
#endif
#endif
if ((!sock_valid_socket(sock)) || (block < 0) || (block > 1))
return SOCK_ERROR;
#ifdef _WIN32
if (block) varblock = 0;
return ioctlsocket(sock, FIONBIO, &varblock);
#else
return fcntl(sock, F_SETFL, (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_write_bytes
**
** write bytes to the socket
** this function will _NOT_ block
*/
int sock_write_bytes(sock_t sock, const void *buff, 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
**
** 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, size_t 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
*/
#ifdef HAVE_POLL
int sock_connected (sock_t sock, int timeout)
{
struct pollfd check;
int val = SOCK_ERROR;
socklen_t size = sizeof val;
check.fd = sock;
check.events = POLLOUT;
switch (poll (&check, 1, timeout*1000))
{
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;
}
}
#else
int sock_connected (sock_t 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;
}
}
#endif
sock_t sock_connect_wto (const char *hostname, int port, int timeout)
{
return sock_connect_wto_bind(hostname, port, NULL, timeout);
}
#ifdef HAVE_GETADDRINFO
sock_t sock_connect_non_blocking (const char *hostname, 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, 0);
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_bind (const char *hostname, int port, const char *bnd, int timeout)
{
sock_t sock = SOCK_ERROR;
struct addrinfo *ai, *head, *b_head=NULL, 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, 0);
if (bnd)
{
struct addrinfo b_hints;
memset (&b_hints, 0, sizeof(b_hints));
b_hints.ai_family = ai->ai_family;
b_hints.ai_socktype = ai->ai_socktype;
b_hints.ai_protocol = ai->ai_protocol;
if (getaddrinfo (bnd, NULL, &b_hints, &b_head) ||
bind (sock, b_head->ai_addr, b_head->ai_addrlen) < 0)
{
sock_close (sock);
sock = SOCK_ERROR;
break;
}
}
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, 1);
break;
}
}
sock_close (sock);
sock = SOCK_ERROR;
}
if (sock != SOCK_ERROR)
break;
}
ai = ai->ai_next;
}
if (b_head)
freeaddrinfo (b_head);
freeaddrinfo (head);
return sock;
}
sock_t sock_get_server_socket (int port, const char *sinterface, bool prefer_inet6)
{
struct sockaddr_storage sa;
struct addrinfo hints, *res, *ai;
char service [16];
int sock;
if (port < 0)
return SOCK_ERROR;
#ifndef AF_INET6
prefer_inet6 = false;
#endif
memset(&sa, 0, sizeof(sa));
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_flags = AI_PASSIVE | AI_ADDRCONFIG | AI_NUMERICSERV | AI_NUMERICHOST;
hints.ai_socktype = SOCK_STREAM;
snprintf(service, sizeof(service), "%d", port);
if (getaddrinfo(sinterface, service, &hints, &res))
return SOCK_ERROR;
while (true) {
for (ai = res; ai; ai = ai->ai_next) {
int on = 1;
#ifdef AF_INET6
if (prefer_inet6 && ai->ai_family != AF_INET6)
continue;
#endif
sock = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
if (sock < 0)
continue;
setsockopt(sock, SOL_SOCKET, SO_REUSEADDR, (const void *)&on, sizeof(on));
#ifdef IPV6_V6ONLY
on = 0;
setsockopt(sock, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof(on));
#endif
if (bind(sock, ai->ai_addr, ai->ai_addrlen) < 0){
sock_close(sock);
continue;
}
freeaddrinfo(res);
return sock;
}
if (!prefer_inet6)
break;
prefer_inet6 = false;
}
freeaddrinfo(res);
return SOCK_ERROR;
}
#else
int sock_try_connection (sock_t sock, const char *hostname, unsigned int 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((short)port);
return connect(sock, (struct sockaddr *)&server, sizeof(server));
}
sock_t sock_connect_non_blocking (const char *hostname, unsigned port)
{
sock_t sock;
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock == SOCK_ERROR)
return SOCK_ERROR;
sock_set_blocking (sock, 0);
sock_try_connection (sock, hostname, port);
return sock;
}
sock_t sock_connect_wto_bind (const char *hostname, int port, const char *bnd, int timeout)
{
sock_t sock;
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock == SOCK_ERROR)
return SOCK_ERROR;
if (bnd)
{
struct sockaddr_in sa;
memset(&sa, 0, sizeof(sa));
sa.sin_family = AF_INET;
if (inet_aton (bnd, &sa.sin_addr) == 0 ||
bind (sock, (struct sockaddr *)&sa, sizeof(sa)) < 0)
{
sock_close (sock);
return SOCK_ERROR;
}
}
if (timeout)
{
sock_set_blocking (sock, 0);
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, 1);
}
else
{
if (sock_try_connection (sock, hostname, port) < 0)
{
sock_close (sock);
sock = SOCK_ERROR;
}
}
return sock;
}
/* 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 (int port, const char *sinterface, bool prefer_inet6)
{
struct sockaddr_in sa;
int error, opt;
sock_t sock;
char ip[MAX_ADDR_LEN];
/* Not supported. */
(void)prefer_inet6;
if (port < 0)
return SOCK_ERROR;
/* defaults */
memset(&sa, 0, sizeof(sa));
/* set the interface to bind to if specified */
if (sinterface != NULL) {
if (!resolver_getip(sinterface, ip, sizeof (ip)))
return SOCK_ERROR;
if (!inet_aton(ip, &sa.sin_addr)) {
return SOCK_ERROR;
} else {
sa.sin_family = AF_INET;
sa.sin_port = htons((short)port);
}
} else {
sa.sin_addr.s_addr = INADDR_ANY;
sa.sin_family = AF_INET;
sa.sin_port = htons((short)port);
}
/* get a socket */
sock = socket (AF_INET, 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, sizeof (struct sockaddr_in));
if (error == -1)
return SOCK_ERROR;
return sock;
}
#endif
void sock_set_send_buffer (sock_t sock, int win_size)
{
setsockopt (sock, SOL_SOCKET, SO_SNDBUF, (char *) &win_size, sizeof(win_size));
}
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);
}
sock_t sock_accept(sock_t serversock, char *ip, size_t len)
{
#ifdef HAVE_GETNAMEINFO
struct sockaddr_storage sa;
#else
struct sockaddr_in sa;
#endif
sock_t ret;
socklen_t slen;
if (ip == NULL || len == 0 || !sock_valid_socket(serversock))
return SOCK_ERROR;
slen = sizeof(sa);
ret = accept(serversock, (struct sockaddr *)&sa, &slen);
if (ret != SOCK_ERROR)
{
#ifdef HAVE_GETNAMEINFO
if (getnameinfo ((struct sockaddr *)&sa, slen, ip, len, NULL, 0, NI_NUMERICHOST))
snprintf (ip, len, "unknown");
#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;
}
bool sock_is_ipv4_mapped_supported(void)
{
#ifdef AF_INET6
struct sockaddr_storage ssock_addr;
struct sockaddr_in6 *ssock_addr_in6 = (struct sockaddr_in6 *)&ssock_addr;
socklen_t ssock_addr_len = sizeof(ssock_addr);
sock_t ssock = SOCK_ERROR;
sock_t csock;
char ip[MAX_ADDR_LEN+1];
ssock = sock_get_server_socket(0, "::", true);
if (ssock == SOCK_ERROR)
return false;
if (listen(ssock, 1) != 0) {
sock_close(ssock);
return false;
}
if (getsockname(ssock, (struct sockaddr*)&ssock_addr, &ssock_addr_len) != 0) {
sock_close(ssock);
return false;
}
if (ssock_addr_len < sizeof(struct sockaddr_in6) || ssock_addr_in6->sin6_family != AF_INET6) {
sock_close(ssock);
return false;
}
csock = sock_connect("127.0.0.1", ntohs(ssock_addr_in6->sin6_port));
if (csock == SOCK_ERROR) {
sock_close(ssock);
return false;
} else {
sock_close(csock);
}
csock = sock_accept(ssock, ip, sizeof(ip));
if (csock == SOCK_ERROR) {
sock_close(ssock);
return false;
} else {
sock_close(csock);
}
sock_close(ssock);
return strcmp(ip, "::ffff:127.0.0.1") == 0 ? true : false;
#else
return false;
#endif
}
sock_family_t sock_get_family(sock_t sock)
{
struct sockaddr addr;
socklen_t len = sizeof(addr);
if (getsockname(sock, &addr, &len) != 0)
return SOCK_FAMILY__ERROR;
if (len < sizeof(addr.sa_family))
return SOCK_FAMILY__ERROR;
switch (addr.sa_family) {
#ifdef AF_UNSPEC
case AF_UNSPEC: return SOCK_FAMILY_UNSPEC; break;
#endif
#ifdef AF_UNIX
case AF_UNIX: return SOCK_FAMILY_UNIX; break;
#endif
#ifdef AF_INET
case AF_INET: return SOCK_FAMILY_INET4; break;
#endif
#ifdef AF_INET6
case AF_INET6: return SOCK_FAMILY_INET6; break;
#endif
#ifdef AF_DECnet
case AF_DECnet: return SOCK_FAMILY_DECnet; break;
#endif
}
return SOCK_FAMILY__ERROR;
}
const char * sock_family_to_string(sock_family_t family)
{
switch (family) {
case SOCK_FAMILY__ERROR: return "<error>"; break;
case SOCK_FAMILY_UNSPEC: return "UNSPEC"; break;
case SOCK_FAMILY_UNIX: return "UNIX"; break;
case SOCK_FAMILY_INET4: return "INET4"; break;
case SOCK_FAMILY_INET6: return "INET6"; break;
case SOCK_FAMILY_DECnet: return "DECnet"; break;
}
return "<unknown>";
}