|
|
/* $OpenBSD: imsg-buffer.c,v 1.12 2019/01/20 02:50:03 bcook Exp $ */
|
|
|
|
|
|
/*
|
|
|
* Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
|
|
|
*
|
|
|
* Permission to use, copy, modify, and distribute this software for any
|
|
|
* purpose with or without fee is hereby granted, provided that the above
|
|
|
* copyright notice and this permission notice appear in all copies.
|
|
|
*
|
|
|
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
|
|
|
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
|
|
|
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
|
|
|
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
|
|
|
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
|
|
|
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
|
|
|
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
|
|
|
*/
|
|
|
|
|
|
#include <sys/types.h>
|
|
|
#include <sys/queue.h>
|
|
|
#include <sys/socket.h>
|
|
|
#include <sys/uio.h>
|
|
|
|
|
|
#include <limits.h>
|
|
|
#include <errno.h>
|
|
|
#include <stdlib.h>
|
|
|
#include <string.h>
|
|
|
#include <unistd.h>
|
|
|
|
|
|
#include "imsg.h"
|
|
|
|
|
|
static int ibuf_realloc(struct ibuf *, size_t);
|
|
|
static void ibuf_enqueue(struct msgbuf *, struct ibuf *);
|
|
|
static void ibuf_dequeue(struct msgbuf *, struct ibuf *);
|
|
|
|
|
|
struct ibuf *
|
|
|
ibuf_open(size_t len)
|
|
|
{
|
|
|
struct ibuf *buf;
|
|
|
|
|
|
if ((buf = calloc(1, sizeof(struct ibuf))) == NULL)
|
|
|
return (NULL);
|
|
|
if ((buf->buf = malloc(len)) == NULL) {
|
|
|
free(buf);
|
|
|
return (NULL);
|
|
|
}
|
|
|
buf->size = buf->max = len;
|
|
|
buf->fd = -1;
|
|
|
|
|
|
return (buf);
|
|
|
}
|
|
|
|
|
|
struct ibuf *
|
|
|
ibuf_dynamic(size_t len, size_t max)
|
|
|
{
|
|
|
struct ibuf *buf;
|
|
|
|
|
|
if (max < len)
|
|
|
return (NULL);
|
|
|
|
|
|
if ((buf = ibuf_open(len)) == NULL)
|
|
|
return (NULL);
|
|
|
|
|
|
if (max > 0)
|
|
|
buf->max = max;
|
|
|
|
|
|
return (buf);
|
|
|
}
|
|
|
|
|
|
static int
|
|
|
ibuf_realloc(struct ibuf *buf, size_t len)
|
|
|
{
|
|
|
unsigned char *b;
|
|
|
|
|
|
/* on static buffers max is eq size and so the following fails */
|
|
|
if (buf->wpos + len > buf->max) {
|
|
|
errno = ERANGE;
|
|
|
return (-1);
|
|
|
}
|
|
|
|
|
|
b = recallocarray(buf->buf, buf->size, buf->wpos + len, 1);
|
|
|
if (b == NULL)
|
|
|
return (-1);
|
|
|
buf->buf = b;
|
|
|
buf->size = buf->wpos + len;
|
|
|
|
|
|
return (0);
|
|
|
}
|
|
|
|
|
|
int
|
|
|
ibuf_add(struct ibuf *buf, const void *data, size_t len)
|
|
|
{
|
|
|
if (buf->wpos + len > buf->size)
|
|
|
if (ibuf_realloc(buf, len) == -1)
|
|
|
return (-1);
|
|
|
|
|
|
memcpy(buf->buf + buf->wpos, data, len);
|
|
|
buf->wpos += len;
|
|
|
return (0);
|
|
|
}
|
|
|
|
|
|
void *
|
|
|
ibuf_reserve(struct ibuf *buf, size_t len)
|
|
|
{
|
|
|
void *b;
|
|
|
|
|
|
if (buf->wpos + len > buf->size)
|
|
|
if (ibuf_realloc(buf, len) == -1)
|
|
|
return (NULL);
|
|
|
|
|
|
b = buf->buf + buf->wpos;
|
|
|
buf->wpos += len;
|
|
|
return (b);
|
|
|
}
|
|
|
|
|
|
void *
|
|
|
ibuf_seek(struct ibuf *buf, size_t pos, size_t len)
|
|
|
{
|
|
|
/* only allowed to seek in already written parts */
|
|
|
if (pos + len > buf->wpos)
|
|
|
return (NULL);
|
|
|
|
|
|
return (buf->buf + pos);
|
|
|
}
|
|
|
|
|
|
size_t
|
|
|
ibuf_size(struct ibuf *buf)
|
|
|
{
|
|
|
return (buf->wpos);
|
|
|
}
|
|
|
|
|
|
size_t
|
|
|
ibuf_left(struct ibuf *buf)
|
|
|
{
|
|
|
return (buf->max - buf->wpos);
|
|
|
}
|
|
|
|
|
|
void
|
|
|
ibuf_close(struct msgbuf *msgbuf, struct ibuf *buf)
|
|
|
{
|
|
|
ibuf_enqueue(msgbuf, buf);
|
|
|
}
|
|
|
|
|
|
int
|
|
|
ibuf_write(struct msgbuf *msgbuf)
|
|
|
{
|
|
|
struct iovec iov[IOV_MAX];
|
|
|
struct ibuf *buf;
|
|
|
unsigned int i = 0;
|
|
|
ssize_t n;
|
|
|
|
|
|
memset(&iov, 0, sizeof(iov));
|
|
|
TAILQ_FOREACH(buf, &msgbuf->bufs, entry) {
|
|
|
if (i >= IOV_MAX)
|
|
|
break;
|
|
|
iov[i].iov_base = buf->buf + buf->rpos;
|
|
|
iov[i].iov_len = buf->wpos - buf->rpos;
|
|
|
i++;
|
|
|
}
|
|
|
|
|
|
again:
|
|
|
if ((n = writev(msgbuf->fd, iov, i)) == -1) {
|
|
|
if (errno == EINTR)
|
|
|
goto again;
|
|
|
if (errno == ENOBUFS)
|
|
|
errno = EAGAIN;
|
|
|
return (-1);
|
|
|
}
|
|
|
|
|
|
if (n == 0) { /* connection closed */
|
|
|
errno = 0;
|
|
|
return (0);
|
|
|
}
|
|
|
|
|
|
msgbuf_drain(msgbuf, n);
|
|
|
|
|
|
return (1);
|
|
|
}
|
|
|
|
|
|
void
|
|
|
ibuf_free(struct ibuf *buf)
|
|
|
{
|
|
|
if (buf == NULL)
|
|
|
return;
|
|
|
freezero(buf->buf, buf->size);
|
|
|
free(buf);
|
|
|
}
|
|
|
|
|
|
void
|
|
|
msgbuf_init(struct msgbuf *msgbuf)
|
|
|
{
|
|
|
msgbuf->queued = 0;
|
|
|
msgbuf->fd = -1;
|
|
|
TAILQ_INIT(&msgbuf->bufs);
|
|
|
}
|
|
|
|
|
|
void
|
|
|
msgbuf_drain(struct msgbuf *msgbuf, size_t n)
|
|
|
{
|
|
|
struct ibuf *buf, *next;
|
|
|
|
|
|
for (buf = TAILQ_FIRST(&msgbuf->bufs); buf != NULL && n > 0;
|
|
|
buf = next) {
|
|
|
next = TAILQ_NEXT(buf, entry);
|
|
|
if (buf->rpos + n >= buf->wpos) {
|
|
|
n -= buf->wpos - buf->rpos;
|
|
|
ibuf_dequeue(msgbuf, buf);
|
|
|
} else {
|
|
|
buf->rpos += n;
|
|
|
n = 0;
|
|
|
}
|
|
|
}
|
|
|
}
|
|
|
|
|
|
void
|
|
|
msgbuf_clear(struct msgbuf *msgbuf)
|
|
|
{
|
|
|
struct ibuf *buf;
|
|
|
|
|
|
while ((buf = TAILQ_FIRST(&msgbuf->bufs)) != NULL)
|
|
|
ibuf_dequeue(msgbuf, buf);
|
|
|
}
|
|
|
|
|
|
int
|
|
|
msgbuf_write(struct msgbuf *msgbuf)
|
|
|
{
|
|
|
struct iovec iov[IOV_MAX];
|
|
|
struct ibuf *buf;
|
|
|
unsigned int i = 0;
|
|
|
ssize_t n;
|
|
|
struct msghdr msg;
|
|
|
struct cmsghdr *cmsg;
|
|
|
union {
|
|
|
struct cmsghdr hdr;
|
|
|
char buf[CMSG_SPACE(sizeof(int))];
|
|
|
} cmsgbuf;
|
|
|
|
|
|
memset(&iov, 0, sizeof(iov));
|
|
|
memset(&msg, 0, sizeof(msg));
|
|
|
memset(&cmsgbuf, 0, sizeof(cmsgbuf));
|
|
|
TAILQ_FOREACH(buf, &msgbuf->bufs, entry) {
|
|
|
if (i >= IOV_MAX)
|
|
|
break;
|
|
|
iov[i].iov_base = buf->buf + buf->rpos;
|
|
|
iov[i].iov_len = buf->wpos - buf->rpos;
|
|
|
i++;
|
|
|
if (buf->fd != -1)
|
|
|
break;
|
|
|
}
|
|
|
|
|
|
msg.msg_iov = iov;
|
|
|
msg.msg_iovlen = i;
|
|
|
|
|
|
if (buf != NULL && buf->fd != -1) {
|
|
|
msg.msg_control = (caddr_t)&cmsgbuf.buf;
|
|
|
msg.msg_controllen = sizeof(cmsgbuf.buf);
|
|
|
cmsg = CMSG_FIRSTHDR(&msg);
|
|
|
cmsg->cmsg_len = CMSG_LEN(sizeof(int));
|
|
|
cmsg->cmsg_level = SOL_SOCKET;
|
|
|
cmsg->cmsg_type = SCM_RIGHTS;
|
|
|
*(int *)CMSG_DATA(cmsg) = buf->fd;
|
|
|
}
|
|
|
|
|
|
again:
|
|
|
if ((n = sendmsg(msgbuf->fd, &msg, 0)) == -1) {
|
|
|
if (errno == EINTR)
|
|
|
goto again;
|
|
|
if (errno == ENOBUFS)
|
|
|
errno = EAGAIN;
|
|
|
return (-1);
|
|
|
}
|
|
|
|
|
|
if (n == 0) { /* connection closed */
|
|
|
errno = 0;
|
|
|
return (0);
|
|
|
}
|
|
|
|
|
|
/*
|
|
|
* assumption: fd got sent if sendmsg sent anything
|
|
|
* this works because fds are passed one at a time
|
|
|
*/
|
|
|
if (buf != NULL && buf->fd != -1) {
|
|
|
close(buf->fd);
|
|
|
buf->fd = -1;
|
|
|
}
|
|
|
|
|
|
msgbuf_drain(msgbuf, n);
|
|
|
|
|
|
return (1);
|
|
|
}
|
|
|
|
|
|
static void
|
|
|
ibuf_enqueue(struct msgbuf *msgbuf, struct ibuf *buf)
|
|
|
{
|
|
|
TAILQ_INSERT_TAIL(&msgbuf->bufs, buf, entry);
|
|
|
msgbuf->queued++;
|
|
|
}
|
|
|
|
|
|
static void
|
|
|
ibuf_dequeue(struct msgbuf *msgbuf, struct ibuf *buf)
|
|
|
{
|
|
|
TAILQ_REMOVE(&msgbuf->bufs, buf, entry);
|
|
|
|
|
|
if (buf->fd != -1)
|
|
|
close(buf->fd);
|
|
|
|
|
|
msgbuf->queued--;
|
|
|
ibuf_free(buf);
|
|
|
}
|