/*-
* Copyright (c) 2009-2010 The FreeBSD Foundation
* Copyright (c) 2011 Pawel Jakub Dawidek <pawel@dawidek.net>
* All rights reserved.
*
* This software was developed by Pawel Jakub Dawidek under sponsorship from
* the FreeBSD Foundation.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/types.h>
#include <sys/socket.h>
#include <errno.h>
#include <fcntl.h>
#include <stdbool.h>
#include <stdlib.h>
#include <strings.h>
#include <unistd.h>
#include "pjdlog.h"
#include "proto_impl.h"
/* Maximum size of packet we want to use when sending data. */
#ifndef MAX_SEND_SIZE
#define MAX_SEND_SIZE 32768
#endif
static bool
blocking_socket(int sock)
{
int flags;
flags = fcntl(sock, F_GETFL);
PJDLOG_ASSERT(flags >= 0);
return ((flags & O_NONBLOCK) == 0);
}
static int
proto_descriptor_send(int sock, int fd)
{
unsigned char ctrl[CMSG_SPACE(sizeof(fd))];
struct msghdr msg;
struct cmsghdr *cmsg;
PJDLOG_ASSERT(sock >= 0);
PJDLOG_ASSERT(fd >= 0);
bzero(&msg, sizeof(msg));
bzero(&ctrl, sizeof(ctrl));
msg.msg_iov = NULL;
msg.msg_iovlen = 0;
msg.msg_control = ctrl;
msg.msg_controllen = sizeof(ctrl);
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
bcopy(&fd, CMSG_DATA(cmsg), sizeof(fd));
if (sendmsg(sock, &msg, 0) == -1)
return (errno);
return (0);
}
int
proto_common_send(int sock, const unsigned char *data, size_t size, int fd)
{
ssize_t done;
size_t sendsize;
int errcount = 0;
PJDLOG_ASSERT(sock >= 0);
if (data == NULL) {
/* The caller is just trying to decide about direction. */
PJDLOG_ASSERT(size == 0);
if (shutdown(sock, SHUT_RD) == -1)
return (errno);
return (0);
}
PJDLOG_ASSERT(data != NULL);
PJDLOG_ASSERT(size > 0);
do {
sendsize = size < MAX_SEND_SIZE ? size : MAX_SEND_SIZE;
done = send(sock, data, sendsize, MSG_NOSIGNAL);
if (done == 0) {
return (ENOTCONN);
} else if (done == -1) {
if (errno == EINTR)
continue;
if (errno == ENOBUFS) {
/*
* If there are no buffers we retry.
* After each try we increase delay before the
* next one and we give up after fifteen times.
* This gives 11s of total wait time.
*/
if (errcount == 15) {
pjdlog_warning("Getting ENOBUFS errors for 11s on send(), giving up.");
} else {
if (errcount == 0)
pjdlog_warning("Got ENOBUFS error on send(), retrying for a bit.");
errcount++;
usleep(100000 * errcount);
continue;
}
}
/*
* If this is blocking socket and we got EAGAIN, this
* means the request timed out. Translate errno to
* ETIMEDOUT, to give administrator a hint to
* eventually increase timeout.
*/
if (errno == EAGAIN && blocking_socket(sock))
errno = ETIMEDOUT;
return (errno);
}
data += done;
size -= done;
} while (size > 0);
if (errcount > 0) {
pjdlog_info("Data sent successfully after %d ENOBUFS error%s.",
errcount, errcount == 1 ? "" : "s");
}
if (fd == -1)
return (0);
return (proto_descriptor_send(sock, fd));
}
static int
proto_descriptor_recv(int sock, int *fdp)
{
unsigned char ctrl[CMSG_SPACE(sizeof(*fdp))];
struct msghdr msg;
struct cmsghdr *cmsg;
PJDLOG_ASSERT(sock >= 0);
PJDLOG_ASSERT(fdp != NULL);
bzero(&msg, sizeof(msg));
bzero(&ctrl, sizeof(ctrl));
msg.msg_iov = NULL;
msg.msg_iovlen = 0;
msg.msg_control = ctrl;
msg.msg_controllen = sizeof(ctrl);
if (recvmsg(sock, &msg, 0) == -1)
return (errno);
cmsg = CMSG_FIRSTHDR(&msg);
if (cmsg == NULL || cmsg->cmsg_level != SOL_SOCKET ||
cmsg->cmsg_type != SCM_RIGHTS) {
return (EINVAL);
}
bcopy(CMSG_DATA(cmsg), fdp, sizeof(*fdp));
return (0);
}
int
proto_common_recv(int sock, unsigned char *data, size_t size, int *fdp)
{
ssize_t done;
PJDLOG_ASSERT(sock >= 0);
if (data == NULL) {
/* The caller is just trying to decide about direction. */
PJDLOG_ASSERT(size == 0);
if (shutdown(sock, SHUT_WR) == -1)
return (errno);
return (0);
}
PJDLOG_ASSERT(data != NULL);
PJDLOG_ASSERT(size > 0);
do {
done = recv(sock, data, size, MSG_WAITALL);
} while (done == -1 && errno == EINTR);
if (done == 0) {
return (ENOTCONN);
} else if (done == -1) {
/*
* If this is blocking socket and we got EAGAIN, this
* means the request timed out. Translate errno to
* ETIMEDOUT, to give administrator a hint to
* eventually increase timeout.
*/
if (errno == EAGAIN && blocking_socket(sock))
errno = ETIMEDOUT;
return (errno);
}
if (fdp == NULL)
return (0);
return (proto_descriptor_recv(sock, fdp));
}
