freebsd-dev/lib/libnv/msgio.c

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/*-
* Copyright (c) 2013 The FreeBSD Foundation
* Copyright (c) 2013 Mariusz Zaborski <oshogbo@FreeBSD.org>
* 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/param.h>
#include <sys/socket.h>
#include <errno.h>
#include <fcntl.h>
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#ifdef HAVE_PJDLOG
#include <pjdlog.h>
#endif
#include "common_impl.h"
#include "msgio.h"
#ifndef HAVE_PJDLOG
#include <assert.h>
#define PJDLOG_ASSERT(...) assert(__VA_ARGS__)
#define PJDLOG_RASSERT(expr, ...) assert(expr)
#define PJDLOG_ABORT(...) abort()
#endif
#define PKG_MAX_SIZE (MCLBYTES / CMSG_SPACE(sizeof(int)) - 1)
static int
msghdr_add_fd(struct cmsghdr *cmsg, int fd)
{
PJDLOG_ASSERT(fd >= 0);
if (!fd_is_valid(fd)) {
errno = EBADF;
return (-1);
}
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_RIGHTS;
cmsg->cmsg_len = CMSG_LEN(sizeof(fd));
bcopy(&fd, CMSG_DATA(cmsg), sizeof(fd));
return (0);
}
static int
msghdr_get_fd(struct cmsghdr *cmsg)
{
int fd;
if (cmsg == NULL || cmsg->cmsg_level != SOL_SOCKET ||
cmsg->cmsg_type != SCM_RIGHTS ||
cmsg->cmsg_len != CMSG_LEN(sizeof(fd))) {
errno = EINVAL;
return (-1);
}
bcopy(CMSG_DATA(cmsg), &fd, sizeof(fd));
#ifndef MSG_CMSG_CLOEXEC
/*
* If the MSG_CMSG_CLOEXEC flag is not available we cannot set the
* close-on-exec flag atomically, but we still want to set it for
* consistency.
*/
(void) fcntl(fd, F_SETFD, FD_CLOEXEC);
#endif
return (fd);
}
static void
fd_wait(int fd, bool doread)
{
fd_set fds;
PJDLOG_ASSERT(fd >= 0);
FD_ZERO(&fds);
FD_SET(fd, &fds);
(void)select(fd + 1, doread ? &fds : NULL, doread ? NULL : &fds,
NULL, NULL);
}
static int
msg_recv(int sock, struct msghdr *msg)
{
int flags;
PJDLOG_ASSERT(sock >= 0);
#ifdef MSG_CMSG_CLOEXEC
flags = MSG_CMSG_CLOEXEC;
#else
flags = 0;
#endif
for (;;) {
fd_wait(sock, true);
if (recvmsg(sock, msg, flags) == -1) {
if (errno == EINTR)
continue;
return (-1);
}
break;
}
return (0);
}
static int
msg_send(int sock, const struct msghdr *msg)
{
PJDLOG_ASSERT(sock >= 0);
for (;;) {
fd_wait(sock, false);
if (sendmsg(sock, msg, 0) == -1) {
if (errno == EINTR)
continue;
return (-1);
}
break;
}
return (0);
}
int
cred_send(int sock)
{
unsigned char credbuf[CMSG_SPACE(sizeof(struct cmsgcred))];
struct msghdr msg;
struct cmsghdr *cmsg;
struct iovec iov;
uint8_t dummy;
bzero(credbuf, sizeof(credbuf));
bzero(&msg, sizeof(msg));
bzero(&iov, sizeof(iov));
/*
* XXX: We send one byte along with the control message, because
* setting msg_iov to NULL only works if this is the first
* packet send over the socket. Once we send some data we
* won't be able to send credentials anymore. This is most
* likely a kernel bug.
*/
dummy = 0;
iov.iov_base = &dummy;
iov.iov_len = sizeof(dummy);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = credbuf;
msg.msg_controllen = sizeof(credbuf);
cmsg = CMSG_FIRSTHDR(&msg);
cmsg->cmsg_len = CMSG_LEN(sizeof(struct cmsgcred));
cmsg->cmsg_level = SOL_SOCKET;
cmsg->cmsg_type = SCM_CREDS;
if (msg_send(sock, &msg) == -1)
return (-1);
return (0);
}
int
cred_recv(int sock, struct cmsgcred *cred)
{
unsigned char credbuf[CMSG_SPACE(sizeof(struct cmsgcred))];
struct msghdr msg;
struct cmsghdr *cmsg;
struct iovec iov;
uint8_t dummy;
bzero(credbuf, sizeof(credbuf));
bzero(&msg, sizeof(msg));
bzero(&iov, sizeof(iov));
iov.iov_base = &dummy;
iov.iov_len = sizeof(dummy);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = credbuf;
msg.msg_controllen = sizeof(credbuf);
if (msg_recv(sock, &msg) == -1)
return (-1);
cmsg = CMSG_FIRSTHDR(&msg);
if (cmsg == NULL ||
cmsg->cmsg_len != CMSG_LEN(sizeof(struct cmsgcred)) ||
cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_CREDS) {
errno = EINVAL;
return (-1);
}
bcopy(CMSG_DATA(cmsg), cred, sizeof(*cred));
return (0);
}
static int
fd_package_send(int sock, const int *fds, size_t nfds)
{
struct msghdr msg;
struct cmsghdr *cmsg;
struct iovec iov;
unsigned int i;
int serrno, ret;
uint8_t dummy;
PJDLOG_ASSERT(sock >= 0);
PJDLOG_ASSERT(fds != NULL);
PJDLOG_ASSERT(nfds > 0);
bzero(&msg, sizeof(msg));
/*
* XXX: Look into cred_send function for more details.
*/
dummy = 0;
iov.iov_base = &dummy;
iov.iov_len = sizeof(dummy);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_controllen = nfds * CMSG_SPACE(sizeof(int));
msg.msg_control = calloc(1, msg.msg_controllen);
if (msg.msg_control == NULL)
return (-1);
ret = -1;
for (i = 0, cmsg = CMSG_FIRSTHDR(&msg); i < nfds && cmsg != NULL;
i++, cmsg = CMSG_NXTHDR(&msg, cmsg)) {
if (msghdr_add_fd(cmsg, fds[i]) == -1)
goto end;
}
if (msg_send(sock, &msg) == -1)
goto end;
ret = 0;
end:
serrno = errno;
free(msg.msg_control);
errno = serrno;
return (ret);
}
static int
fd_package_recv(int sock, int *fds, size_t nfds)
{
struct msghdr msg;
struct cmsghdr *cmsg;
unsigned int i;
int serrno, ret;
struct iovec iov;
uint8_t dummy;
PJDLOG_ASSERT(sock >= 0);
PJDLOG_ASSERT(nfds > 0);
PJDLOG_ASSERT(fds != NULL);
i = 0;
bzero(&msg, sizeof(msg));
bzero(&iov, sizeof(iov));
/*
* XXX: Look into cred_send function for more details.
*/
iov.iov_base = &dummy;
iov.iov_len = sizeof(dummy);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_controllen = nfds * CMSG_SPACE(sizeof(int));
msg.msg_control = calloc(1, msg.msg_controllen);
if (msg.msg_control == NULL)
return (-1);
ret = -1;
if (msg_recv(sock, &msg) == -1)
goto end;
for (i = 0, cmsg = CMSG_FIRSTHDR(&msg); i < nfds && cmsg != NULL;
i++, cmsg = CMSG_NXTHDR(&msg, cmsg)) {
fds[i] = msghdr_get_fd(cmsg);
if (fds[i] < 0)
break;
}
if (cmsg != NULL || i < nfds) {
int fd;
/*
* We need to close all received descriptors, even if we have
* different control message (eg. SCM_CREDS) in between.
*/
for (cmsg = CMSG_FIRSTHDR(&msg); cmsg != NULL;
cmsg = CMSG_NXTHDR(&msg, cmsg)) {
fd = msghdr_get_fd(cmsg);
if (fd >= 0)
close(fd);
}
errno = EINVAL;
goto end;
}
ret = 0;
end:
serrno = errno;
free(msg.msg_control);
errno = serrno;
return (ret);
}
int
fd_recv(int sock, int *fds, size_t nfds)
{
unsigned int i, step, j;
int ret, serrno;
if (nfds == 0 || fds == NULL) {
errno = EINVAL;
return (-1);
}
ret = i = step = 0;
while (i < nfds) {
if (PKG_MAX_SIZE < nfds - i)
step = PKG_MAX_SIZE;
else
step = nfds - i;
ret = fd_package_recv(sock, fds + i, step);
if (ret != 0) {
/* Close all received descriptors. */
serrno = errno;
for (j = 0; j < i; j++)
close(fds[j]);
errno = serrno;
break;
}
i += step;
}
return (ret);
}
int
fd_send(int sock, const int *fds, size_t nfds)
{
unsigned int i, step;
int ret;
if (nfds == 0 || fds == NULL) {
errno = EINVAL;
return (-1);
}
ret = i = step = 0;
while (i < nfds) {
if (PKG_MAX_SIZE < nfds - i)
step = PKG_MAX_SIZE;
else
step = nfds - i;
ret = fd_package_send(sock, fds + i, step);
if (ret != 0)
break;
i += step;
}
return (ret);
}
int
buf_send(int sock, void *buf, size_t size)
{
ssize_t done;
unsigned char *ptr;
PJDLOG_ASSERT(sock >= 0);
PJDLOG_ASSERT(size > 0);
PJDLOG_ASSERT(buf != NULL);
ptr = buf;
do {
fd_wait(sock, false);
done = send(sock, ptr, size, 0);
if (done == -1) {
if (errno == EINTR)
continue;
return (-1);
} else if (done == 0) {
errno = ENOTCONN;
return (-1);
}
size -= done;
ptr += done;
} while (size > 0);
return (0);
}
int
buf_recv(int sock, void *buf, size_t size)
{
ssize_t done;
unsigned char *ptr;
PJDLOG_ASSERT(sock >= 0);
PJDLOG_ASSERT(buf != NULL);
ptr = buf;
while (size > 0) {
fd_wait(sock, true);
done = recv(sock, ptr, size, 0);
if (done == -1) {
if (errno == EINTR)
continue;
return (-1);
} else if (done == 0) {
errno = ENOTCONN;
return (-1);
}
size -= done;
ptr += done;
}
return (0);
}