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ruby--ruby/ext/socket/init.c
normal 7914a8726e socket (rsock_connect): fix and refactor for blocking
* ext/socket/init.c (rsock_connect): refactor for blocking
  (wait_connectable): clear error before wait
  [Bug #9356]

We no longer use non-blocking sockets to emulate blocking behavior,
so eliminate error-prone and confusing platform-dependent code.
According to POSIX, connect() only needs to be called once in the
face of EINTR, so do not loop on it.

Before waiting on connect, drop any pending errors, since
rb_wait_for_single_fd may not clear the existing error
properly.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47617 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
2014-09-17 21:20:58 +00:00

615 lines
14 KiB
C

/************************************************
init.c -
created at: Thu Mar 31 12:21:29 JST 1994
Copyright (C) 1993-2007 Yukihiro Matsumoto
************************************************/
#include "rubysocket.h"
VALUE rb_cBasicSocket;
VALUE rb_cIPSocket;
VALUE rb_cTCPSocket;
VALUE rb_cTCPServer;
VALUE rb_cUDPSocket;
#ifdef AF_UNIX
VALUE rb_cUNIXSocket;
VALUE rb_cUNIXServer;
#endif
VALUE rb_cSocket;
VALUE rb_cAddrinfo;
VALUE rb_eSocket;
#ifdef SOCKS
VALUE rb_cSOCKSSocket;
#endif
int rsock_do_not_reverse_lookup = 1;
void
rsock_raise_socket_error(const char *reason, int error)
{
#ifdef EAI_SYSTEM
if (error == EAI_SYSTEM) rb_sys_fail(reason);
#endif
rb_raise(rb_eSocket, "%s: %s", reason, gai_strerror(error));
}
VALUE
rsock_init_sock(VALUE sock, int fd)
{
rb_io_t *fp;
#ifndef _WIN32
struct stat sbuf;
if (fstat(fd, &sbuf) < 0)
rb_sys_fail("fstat(2)");
rb_update_max_fd(fd);
if (!S_ISSOCK(sbuf.st_mode))
rb_raise(rb_eArgError, "not a socket file descriptor");
#else
rb_update_max_fd(fd);
if (!rb_w32_is_socket(fd))
rb_raise(rb_eArgError, "not a socket file descriptor");
#endif
MakeOpenFile(sock, fp);
fp->fd = fd;
fp->mode = FMODE_READWRITE|FMODE_DUPLEX;
rb_io_ascii8bit_binmode(sock);
if (rsock_do_not_reverse_lookup) {
fp->mode |= FMODE_NOREVLOOKUP;
}
rb_io_synchronized(fp);
return sock;
}
VALUE
rsock_sendto_blocking(void *data)
{
struct rsock_send_arg *arg = data;
VALUE mesg = arg->mesg;
return (VALUE)sendto(arg->fd, RSTRING_PTR(mesg), RSTRING_LEN(mesg),
arg->flags, arg->to, arg->tolen);
}
VALUE
rsock_send_blocking(void *data)
{
struct rsock_send_arg *arg = data;
VALUE mesg = arg->mesg;
return (VALUE)send(arg->fd, RSTRING_PTR(mesg), RSTRING_LEN(mesg),
arg->flags);
}
struct recvfrom_arg {
int fd, flags;
VALUE str;
socklen_t alen;
union_sockaddr buf;
};
static VALUE
recvfrom_blocking(void *data)
{
struct recvfrom_arg *arg = data;
socklen_t len0 = arg->alen;
ssize_t ret;
ret = recvfrom(arg->fd, RSTRING_PTR(arg->str), RSTRING_LEN(arg->str),
arg->flags, &arg->buf.addr, &arg->alen);
if (ret != -1 && len0 < arg->alen)
arg->alen = len0;
return (VALUE)ret;
}
VALUE
rsock_s_recvfrom(VALUE sock, int argc, VALUE *argv, enum sock_recv_type from)
{
rb_io_t *fptr;
VALUE str, klass;
struct recvfrom_arg arg;
VALUE len, flg;
long buflen;
long slen;
rb_scan_args(argc, argv, "11", &len, &flg);
if (flg == Qnil) arg.flags = 0;
else arg.flags = NUM2INT(flg);
buflen = NUM2INT(len);
GetOpenFile(sock, fptr);
if (rb_io_read_pending(fptr)) {
rb_raise(rb_eIOError, "recv for buffered IO");
}
arg.fd = fptr->fd;
arg.alen = (socklen_t)sizeof(arg.buf);
arg.str = str = rb_tainted_str_new(0, buflen);
klass = RBASIC(str)->klass;
rb_obj_hide(str);
while (rb_io_check_closed(fptr),
rsock_maybe_wait_fd(arg.fd),
(slen = BLOCKING_REGION_FD(recvfrom_blocking, &arg)) < 0) {
if (!rb_io_wait_readable(fptr->fd)) {
rb_sys_fail("recvfrom(2)");
}
if (RBASIC(str)->klass || RSTRING_LEN(str) != buflen) {
rb_raise(rb_eRuntimeError, "buffer string modified");
}
}
rb_obj_reveal(str, klass);
if (slen < RSTRING_LEN(str)) {
rb_str_set_len(str, slen);
}
rb_obj_taint(str);
switch (from) {
case RECV_RECV:
return str;
case RECV_IP:
#if 0
if (arg.alen != sizeof(struct sockaddr_in)) {
rb_raise(rb_eTypeError, "sockaddr size differs - should not happen");
}
#endif
if (arg.alen && arg.alen != sizeof(arg.buf)) /* OSX doesn't return a from result for connection-oriented sockets */
return rb_assoc_new(str, rsock_ipaddr(&arg.buf.addr, arg.alen, fptr->mode & FMODE_NOREVLOOKUP));
else
return rb_assoc_new(str, Qnil);
#ifdef HAVE_SYS_UN_H
case RECV_UNIX:
return rb_assoc_new(str, rsock_unixaddr(&arg.buf.un, arg.alen));
#endif
case RECV_SOCKET:
return rb_assoc_new(str, rsock_io_socket_addrinfo(sock, &arg.buf.addr, arg.alen));
default:
rb_bug("rsock_s_recvfrom called with bad value");
}
}
VALUE
rsock_s_recvfrom_nonblock(VALUE sock, int argc, VALUE *argv, enum sock_recv_type from)
{
rb_io_t *fptr;
VALUE str;
union_sockaddr buf;
socklen_t alen = (socklen_t)sizeof buf;
VALUE len, flg;
long buflen;
long slen;
int fd, flags;
VALUE addr = Qnil;
socklen_t len0;
rb_scan_args(argc, argv, "11", &len, &flg);
if (flg == Qnil) flags = 0;
else flags = NUM2INT(flg);
buflen = NUM2INT(len);
#ifdef MSG_DONTWAIT
/* MSG_DONTWAIT avoids the race condition between fcntl and recvfrom.
It is not portable, though. */
flags |= MSG_DONTWAIT;
#endif
GetOpenFile(sock, fptr);
if (rb_io_read_pending(fptr)) {
rb_raise(rb_eIOError, "recvfrom for buffered IO");
}
fd = fptr->fd;
str = rb_tainted_str_new(0, buflen);
rb_io_check_closed(fptr);
rb_io_set_nonblock(fptr);
len0 = alen;
slen = recvfrom(fd, RSTRING_PTR(str), buflen, flags, &buf.addr, &alen);
if (slen != -1 && len0 < alen)
alen = len0;
if (slen < 0) {
switch (errno) {
case EAGAIN:
#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
case EWOULDBLOCK:
#endif
rb_readwrite_sys_fail(RB_IO_WAIT_READABLE, "recvfrom(2) would block");
}
rb_sys_fail("recvfrom(2)");
}
if (slen < RSTRING_LEN(str)) {
rb_str_set_len(str, slen);
}
rb_obj_taint(str);
switch (from) {
case RECV_RECV:
return str;
case RECV_IP:
if (alen && alen != sizeof(buf)) /* connection-oriented socket may not return a from result */
addr = rsock_ipaddr(&buf.addr, alen, fptr->mode & FMODE_NOREVLOOKUP);
break;
case RECV_SOCKET:
addr = rsock_io_socket_addrinfo(sock, &buf.addr, alen);
break;
default:
rb_bug("rsock_s_recvfrom_nonblock called with bad value");
}
return rb_assoc_new(str, addr);
}
/* returns true if SOCK_CLOEXEC is supported */
int rsock_detect_cloexec(int fd)
{
#ifdef SOCK_CLOEXEC
int flags = fcntl(fd, F_GETFD);
if (flags == -1)
rb_bug("rsock_detect_cloexec: fcntl(%d, F_GETFD) failed: %s", fd, strerror(errno));
if (flags & FD_CLOEXEC)
return 1;
#endif
return 0;
}
#ifdef SOCK_CLOEXEC
static int
rsock_socket0(int domain, int type, int proto)
{
int ret;
static int cloexec_state = -1; /* <0: unknown, 0: ignored, >0: working */
if (cloexec_state > 0) { /* common path, if SOCK_CLOEXEC is defined */
ret = socket(domain, type|SOCK_CLOEXEC, proto);
if (ret >= 0) {
if (ret <= 2)
goto fix_cloexec;
goto update_max_fd;
}
}
else if (cloexec_state < 0) { /* usually runs once only for detection */
ret = socket(domain, type|SOCK_CLOEXEC, proto);
if (ret >= 0) {
cloexec_state = rsock_detect_cloexec(ret);
if (cloexec_state == 0 || ret <= 2)
goto fix_cloexec;
goto update_max_fd;
}
else if (ret == -1 && errno == EINVAL) {
/* SOCK_CLOEXEC is available since Linux 2.6.27. Linux 2.6.18 fails with EINVAL */
ret = socket(domain, type, proto);
if (ret != -1) {
cloexec_state = 0;
/* fall through to fix_cloexec */
}
}
}
else { /* cloexec_state == 0 */
ret = socket(domain, type, proto);
}
if (ret == -1)
return -1;
fix_cloexec:
rb_maygvl_fd_fix_cloexec(ret);
update_max_fd:
rb_update_max_fd(ret);
return ret;
}
#else /* !SOCK_CLOEXEC */
static int
rsock_socket0(int domain, int type, int proto)
{
int ret = socket(domain, type, proto);
if (ret == -1)
return -1;
rb_fd_fix_cloexec(ret);
return ret;
}
#endif /* !SOCK_CLOEXEC */
int
rsock_socket(int domain, int type, int proto)
{
int fd;
fd = rsock_socket0(domain, type, proto);
if (fd < 0) {
if (errno == EMFILE || errno == ENFILE) {
rb_gc();
fd = rsock_socket0(domain, type, proto);
}
}
if (0 <= fd)
rb_update_max_fd(fd);
return fd;
}
/* emulate blocking connect behavior on EINTR or non-blocking socket */
static int
wait_connectable(int fd)
{
int sockerr, revents;
socklen_t sockerrlen;
/* only to clear pending error */
sockerrlen = (socklen_t)sizeof(sockerr);
if (getsockopt(fd, SOL_SOCKET, SO_ERROR, (void *)&sockerr, &sockerrlen) < 0)
return -1;
/*
* Stevens book says, successful finish turn on RB_WAITFD_OUT and
* failure finish turn on both RB_WAITFD_IN and RB_WAITFD_OUT.
* So it's enough to wait only RB_WAITFD_OUT and check the pending error
* by getsockopt().
*
* Note: rb_wait_for_single_fd already retries on EINTR/ERESTART
*/
revents = rb_wait_for_single_fd(fd, RB_WAITFD_IN|RB_WAITFD_OUT, NULL);
if (revents < 0)
return -1;
sockerrlen = (socklen_t)sizeof(sockerr);
if (getsockopt(fd, SOL_SOCKET, SO_ERROR, (void *)&sockerr, &sockerrlen) < 0)
return -1;
switch (sockerr) {
case 0:
/*
* be defensive in case some platforms set SO_ERROR on the original,
* interrupted connect()
*/
case EINTR:
#ifdef ERESTART
case ERESTART:
#endif
case EAGAIN:
#ifdef EINPROGRESS
case EINPROGRESS:
#endif
#ifdef EALREADY
case EALREADY:
#endif
#ifdef EISCONN
case EISCONN:
#endif
return 0; /* success */
default:
/* likely (but not limited to): ECONNREFUSED, ETIMEDOUT, EHOSTUNREACH */
errno = sockerr;
return -1;
}
return 0;
}
struct connect_arg {
int fd;
const struct sockaddr *sockaddr;
socklen_t len;
};
static VALUE
connect_blocking(void *data)
{
struct connect_arg *arg = data;
return (VALUE)connect(arg->fd, arg->sockaddr, arg->len);
}
#if defined(SOCKS) && !defined(SOCKS5)
static VALUE
socks_connect_blocking(void *data)
{
struct connect_arg *arg = data;
return (VALUE)Rconnect(arg->fd, arg->sockaddr, arg->len);
}
#endif
int
rsock_connect(int fd, const struct sockaddr *sockaddr, int len, int socks)
{
int status;
rb_blocking_function_t *func = connect_blocking;
struct connect_arg arg;
arg.fd = fd;
arg.sockaddr = sockaddr;
arg.len = len;
#if defined(SOCKS) && !defined(SOCKS5)
if (socks) func = socks_connect_blocking;
#endif
status = (int)BLOCKING_REGION_FD(func, &arg);
if (status < 0) {
switch (errno) {
case EINTR:
#ifdef ERESTART
case ERESTART:
#endif
case EAGAIN:
#ifdef EINPROGRESS
case EINPROGRESS:
#endif
return wait_connectable(fd);
}
}
return status;
}
static void
make_fd_nonblock(int fd)
{
int flags;
#ifdef F_GETFL
flags = fcntl(fd, F_GETFL);
if (flags == -1) {
rb_sys_fail("fnctl(2)");
}
#else
flags = 0;
#endif
flags |= O_NONBLOCK;
if (fcntl(fd, F_SETFL, flags) == -1) {
rb_sys_fail("fnctl(2)");
}
}
static int
cloexec_accept(int socket, struct sockaddr *address, socklen_t *address_len)
{
int ret;
socklen_t len0 = 0;
#ifdef HAVE_ACCEPT4
static int try_accept4 = 1;
#endif
if (address_len) len0 = *address_len;
#ifdef HAVE_ACCEPT4
if (try_accept4) {
int flags = 0;
#ifdef SOCK_CLOEXEC
flags |= SOCK_CLOEXEC;
#endif
ret = accept4(socket, address, address_len, flags);
/* accept4 is available since Linux 2.6.28, glibc 2.10. */
if (ret != -1) {
if (ret <= 2)
rb_maygvl_fd_fix_cloexec(ret);
if (address_len && len0 < *address_len) *address_len = len0;
return ret;
}
if (errno != ENOSYS) {
return -1;
}
try_accept4 = 0;
}
#endif
ret = accept(socket, address, address_len);
if (ret == -1) return -1;
if (address_len && len0 < *address_len) *address_len = len0;
rb_maygvl_fd_fix_cloexec(ret);
return ret;
}
VALUE
rsock_s_accept_nonblock(VALUE klass, rb_io_t *fptr, struct sockaddr *sockaddr, socklen_t *len)
{
int fd2;
rb_secure(3);
rb_io_set_nonblock(fptr);
fd2 = cloexec_accept(fptr->fd, (struct sockaddr*)sockaddr, len);
if (fd2 < 0) {
switch (errno) {
case EAGAIN:
#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
case EWOULDBLOCK:
#endif
case ECONNABORTED:
#if defined EPROTO
case EPROTO:
#endif
rb_readwrite_sys_fail(RB_IO_WAIT_READABLE, "accept(2) would block");
}
rb_sys_fail("accept(2)");
}
rb_update_max_fd(fd2);
make_fd_nonblock(fd2);
return rsock_init_sock(rb_obj_alloc(klass), fd2);
}
struct accept_arg {
int fd;
struct sockaddr *sockaddr;
socklen_t *len;
};
static VALUE
accept_blocking(void *data)
{
struct accept_arg *arg = data;
return (VALUE)cloexec_accept(arg->fd, arg->sockaddr, arg->len);
}
VALUE
rsock_s_accept(VALUE klass, int fd, struct sockaddr *sockaddr, socklen_t *len)
{
int fd2;
int retry = 0;
struct accept_arg arg;
rb_secure(3);
arg.fd = fd;
arg.sockaddr = sockaddr;
arg.len = len;
retry:
rsock_maybe_wait_fd(fd);
fd2 = (int)BLOCKING_REGION_FD(accept_blocking, &arg);
if (fd2 < 0) {
switch (errno) {
case EMFILE:
case ENFILE:
if (retry) break;
rb_gc();
retry = 1;
goto retry;
default:
if (!rb_io_wait_readable(fd)) break;
retry = 0;
goto retry;
}
rb_sys_fail("accept(2)");
}
rb_update_max_fd(fd2);
if (!klass) return INT2NUM(fd2);
return rsock_init_sock(rb_obj_alloc(klass), fd2);
}
int
rsock_getfamily(int sockfd)
{
union_sockaddr ss;
socklen_t sslen = (socklen_t)sizeof(ss);
ss.addr.sa_family = AF_UNSPEC;
if (getsockname(sockfd, &ss.addr, &sslen) < 0)
return AF_UNSPEC;
return ss.addr.sa_family;
}
void
rsock_init_socket_init()
{
/*
* SocketError is the error class for socket.
*/
rb_eSocket = rb_define_class("SocketError", rb_eStandardError);
rsock_init_ipsocket();
rsock_init_tcpsocket();
rsock_init_tcpserver();
rsock_init_sockssocket();
rsock_init_udpsocket();
rsock_init_unixsocket();
rsock_init_unixserver();
rsock_init_sockopt();
rsock_init_ancdata();
rsock_init_addrinfo();
rsock_init_sockifaddr();
rsock_init_socket_constants();
}