freebsd-nq/contrib/ntp/libntp/socket.c

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/*
* socket.c - low-level socket operations
*/
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <stdio.h>
#include "ntp.h"
#include "ntp_io.h"
#include "ntp_net.h"
#include "ntp_debug.h"
/*
* Windows C runtime ioctl() can't deal properly with sockets,
* map to ioctlsocket for this source file.
*/
#ifdef SYS_WINNT
#define ioctl(fd, opt, val) ioctlsocket(fd, opt, (u_long *)(val))
#endif
/*
* on Unix systems the stdio library typically
* makes use of file descriptors in the lower
* integer range. stdio usually will make use
* of the file descriptors in the range of
* [0..FOPEN_MAX)
* in order to keep this range clean, for socket
* file descriptors we attempt to move them above
* FOPEN_MAX. This is not as easy as it sounds as
* FOPEN_MAX changes from implementation to implementation
* and may exceed to current file decriptor limits.
* We are using following strategy:
* - keep a current socket fd boundary initialized with
* max(0, min(GETDTABLESIZE() - FD_CHUNK, FOPEN_MAX))
* - attempt to move the descriptor to the boundary or
* above.
* - if that fails and boundary > 0 set boundary
* to min(0, socket_fd_boundary - FD_CHUNK)
* -> retry
* if failure and boundary == 0 return old fd
* - on success close old fd return new fd
*
* effects:
* - fds will be moved above the socket fd boundary
* if at all possible.
* - the socket boundary will be reduced until
* allocation is possible or 0 is reached - at this
* point the algrithm will be disabled
*/
SOCKET
move_fd(
SOCKET fd
)
{
#if !defined(SYS_WINNT) && defined(F_DUPFD)
#ifndef FD_CHUNK
#define FD_CHUNK 10
#endif
#ifndef FOPEN_MAX
#define FOPEN_MAX 20
#endif
/*
* number of fds we would like to have for
* stdio FILE* available.
* we can pick a "low" number as our use of
* FILE* is limited to log files and temporarily
* to data and config files. Except for log files
* we don't keep the other FILE* open beyond the
* scope of the function that opened it.
*/
#ifndef FD_PREFERRED_SOCKBOUNDARY
#define FD_PREFERRED_SOCKBOUNDARY 48
#endif
static SOCKET socket_boundary = -1;
SOCKET newfd;
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REQUIRE((int)fd >= 0);
/*
* check whether boundary has be set up
* already
*/
if (socket_boundary == -1) {
socket_boundary = max(0, min(GETDTABLESIZE() - FD_CHUNK,
min(FOPEN_MAX, FD_PREFERRED_SOCKBOUNDARY)));
TRACE(1, ("move_fd: estimated max descriptors: %d, "
"initial socket boundary: %d\n",
GETDTABLESIZE(), socket_boundary));
}
/*
* Leave a space for stdio to work in. potentially moving the
* socket_boundary lower until allocation succeeds.
*/
do {
if (fd >= 0 && fd < socket_boundary) {
/* inside reserved range: attempt to move fd */
newfd = fcntl(fd, F_DUPFD, socket_boundary);
if (newfd != -1) {
/* success: drop the old one - return the new one */
close(fd);
return newfd;
}
} else {
/* outside reserved range: no work - return the original one */
return fd;
}
socket_boundary = max(0, socket_boundary - FD_CHUNK);
TRACE(1, ("move_fd: selecting new socket boundary: %d\n",
socket_boundary));
} while (socket_boundary > 0);
#else
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ENSURE((int)fd >= 0);
#endif /* !defined(SYS_WINNT) && defined(F_DUPFD) */
return fd;
}
/*
* make_socket_nonblocking() - set up descriptor to be non blocking
*/
void
make_socket_nonblocking(
SOCKET fd
)
{
/*
* set non-blocking,
*/
#ifdef USE_FIONBIO
/* in vxWorks we use FIONBIO, but the others are defined for old
* systems, so all hell breaks loose if we leave them defined
*/
#undef O_NONBLOCK
#undef FNDELAY
#undef O_NDELAY
#endif
#if defined(O_NONBLOCK) /* POSIX */
if (fcntl(fd, F_SETFL, O_NONBLOCK) < 0) {
msyslog(LOG_ERR,
"fcntl(O_NONBLOCK) fails on fd #%d: %m", fd);
exit(1);
}
#elif defined(FNDELAY)
if (fcntl(fd, F_SETFL, FNDELAY) < 0) {
msyslog(LOG_ERR, "fcntl(FNDELAY) fails on fd #%d: %m",
fd);
exit(1);
}
#elif defined(O_NDELAY) /* generally the same as FNDELAY */
if (fcntl(fd, F_SETFL, O_NDELAY) < 0) {
msyslog(LOG_ERR, "fcntl(O_NDELAY) fails on fd #%d: %m",
fd);
exit(1);
}
#elif defined(FIONBIO)
{
int on = 1;
if (ioctl(fd, FIONBIO, &on) < 0) {
msyslog(LOG_ERR,
"ioctl(FIONBIO) fails on fd #%d: %m",
fd);
exit(1);
}
}
#elif defined(FIOSNBIO)
if (ioctl(fd, FIOSNBIO, &on) < 0) {
msyslog(LOG_ERR,
"ioctl(FIOSNBIO) fails on fd #%d: %m", fd);
exit(1);
}
#else
# include "Bletch: Need non-blocking I/O!"
#endif
}
#if 0
/* The following subroutines should probably be moved here */
static SOCKET
open_socket(
sockaddr_u * addr,
int bcast,
int turn_off_reuse,
endpt * interf
)
void
sendpkt(
sockaddr_u * dest,
struct interface * ep,
int ttl,
struct pkt * pkt,
int len
)
static inline int
read_refclock_packet(SOCKET fd, struct refclockio *rp, l_fp ts)
static inline int
read_network_packet(
SOCKET fd,
struct interface * itf,
l_fp ts
)
void
kill_asyncio(int startfd)
#endif /* 0 */