HardenedBSD/sys/kern/subr_mchain.c
Ruslan Ermilov ea26d58729 Replaced the misleading uses of a historical artefact M_TRYWAIT with M_WAIT.
Removed dead code that assumed that M_TRYWAIT can return NULL; it's not true
since the advent of MBUMA.

Reviewed by:	arch

There are ongoing disputes as to whether we want to switch to directly using
UMA flags M_WAITOK/M_NOWAIT for mbuf(9) allocation.
2008-03-25 09:39:02 +00:00

536 lines
11 KiB
C

/*-
* Copyright (c) 2000, 2001 Boris Popov
* All rights reserved.
*
* 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.
* 4. Neither the name of the author nor the names of any co-contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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/systm.h>
#include <sys/endian.h>
#include <sys/errno.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/uio.h>
#include <sys/mchain.h>
MODULE_VERSION(libmchain, 1);
#define MBERROR(format, ...) printf("%s(%d): "format, __func__ , \
__LINE__ , ## __VA_ARGS__)
#define MBPANIC(format, ...) printf("%s(%d): "format, __func__ , \
__LINE__ , ## __VA_ARGS__)
/*
* Various helper functions
*/
int
mb_init(struct mbchain *mbp)
{
struct mbuf *m;
m = m_gethdr(M_WAIT, MT_DATA);
m->m_len = 0;
mb_initm(mbp, m);
return 0;
}
void
mb_initm(struct mbchain *mbp, struct mbuf *m)
{
bzero(mbp, sizeof(*mbp));
mbp->mb_top = mbp->mb_cur = m;
mbp->mb_mleft = M_TRAILINGSPACE(m);
}
void
mb_done(struct mbchain *mbp)
{
if (mbp->mb_top) {
m_freem(mbp->mb_top);
mbp->mb_top = NULL;
}
}
struct mbuf *
mb_detach(struct mbchain *mbp)
{
struct mbuf *m;
m = mbp->mb_top;
mbp->mb_top = NULL;
return m;
}
int
mb_fixhdr(struct mbchain *mbp)
{
return mbp->mb_top->m_pkthdr.len = m_fixhdr(mbp->mb_top);
}
/*
* Check if object of size 'size' fit to the current position and
* allocate new mbuf if not. Advance pointers and increase length of mbuf(s).
* Return pointer to the object placeholder or NULL if any error occured.
* Note: size should be <= MLEN
*/
caddr_t
mb_reserve(struct mbchain *mbp, int size)
{
struct mbuf *m, *mn;
caddr_t bpos;
if (size > MLEN)
panic("mb_reserve: size = %d\n", size);
m = mbp->mb_cur;
if (mbp->mb_mleft < size) {
mn = m_get(M_WAIT, MT_DATA);
mbp->mb_cur = m->m_next = mn;
m = mn;
m->m_len = 0;
mbp->mb_mleft = M_TRAILINGSPACE(m);
}
mbp->mb_mleft -= size;
mbp->mb_count += size;
bpos = mtod(m, caddr_t) + m->m_len;
m->m_len += size;
return bpos;
}
int
mb_put_uint8(struct mbchain *mbp, u_int8_t x)
{
return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
}
int
mb_put_uint16be(struct mbchain *mbp, u_int16_t x)
{
x = htobe16(x);
return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
}
int
mb_put_uint16le(struct mbchain *mbp, u_int16_t x)
{
x = htole16(x);
return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
}
int
mb_put_uint32be(struct mbchain *mbp, u_int32_t x)
{
x = htobe32(x);
return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
}
int
mb_put_uint32le(struct mbchain *mbp, u_int32_t x)
{
x = htole32(x);
return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
}
int
mb_put_int64be(struct mbchain *mbp, int64_t x)
{
x = htobe64(x);
return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
}
int
mb_put_int64le(struct mbchain *mbp, int64_t x)
{
x = htole64(x);
return mb_put_mem(mbp, (caddr_t)&x, sizeof(x), MB_MSYSTEM);
}
int
mb_put_mem(struct mbchain *mbp, c_caddr_t source, int size, int type)
{
struct mbuf *m;
caddr_t dst;
c_caddr_t src;
int cplen, error, mleft, count;
size_t srclen, dstlen;
m = mbp->mb_cur;
mleft = mbp->mb_mleft;
while (size > 0) {
if (mleft == 0) {
if (m->m_next == NULL)
m = m_getm(m, size, M_WAIT, MT_DATA);
else
m = m->m_next;
mleft = M_TRAILINGSPACE(m);
continue;
}
cplen = mleft > size ? size : mleft;
srclen = dstlen = cplen;
dst = mtod(m, caddr_t) + m->m_len;
switch (type) {
case MB_MCUSTOM:
srclen = size;
dstlen = mleft;
error = mbp->mb_copy(mbp, source, dst, &srclen, &dstlen);
if (error)
return error;
break;
case MB_MINLINE:
for (src = source, count = cplen; count; count--)
*dst++ = *src++;
break;
case MB_MSYSTEM:
bcopy(source, dst, cplen);
break;
case MB_MUSER:
error = copyin(source, dst, cplen);
if (error)
return error;
break;
case MB_MZERO:
bzero(dst, cplen);
break;
}
size -= srclen;
source += srclen;
m->m_len += dstlen;
mleft -= dstlen;
mbp->mb_count += dstlen;
}
mbp->mb_cur = m;
mbp->mb_mleft = mleft;
return 0;
}
int
mb_put_mbuf(struct mbchain *mbp, struct mbuf *m)
{
mbp->mb_cur->m_next = m;
while (m) {
mbp->mb_count += m->m_len;
if (m->m_next == NULL)
break;
m = m->m_next;
}
mbp->mb_mleft = M_TRAILINGSPACE(m);
mbp->mb_cur = m;
return 0;
}
/*
* copies a uio scatter/gather list to an mbuf chain.
*/
int
mb_put_uio(struct mbchain *mbp, struct uio *uiop, int size)
{
long left;
int mtype, error;
mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
while (size > 0 && uiop->uio_resid) {
if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
return EFBIG;
left = uiop->uio_iov->iov_len;
if (left == 0) {
uiop->uio_iov++;
uiop->uio_iovcnt--;
continue;
}
if (left > size)
left = size;
error = mb_put_mem(mbp, uiop->uio_iov->iov_base, left, mtype);
if (error)
return error;
uiop->uio_offset += left;
uiop->uio_resid -= left;
uiop->uio_iov->iov_base =
(char *)uiop->uio_iov->iov_base + left;
uiop->uio_iov->iov_len -= left;
size -= left;
}
return 0;
}
/*
* Routines for fetching data from an mbuf chain
*/
int
md_init(struct mdchain *mdp)
{
struct mbuf *m;
m = m_gethdr(M_WAIT, MT_DATA);
m->m_len = 0;
md_initm(mdp, m);
return 0;
}
void
md_initm(struct mdchain *mdp, struct mbuf *m)
{
bzero(mdp, sizeof(*mdp));
mdp->md_top = mdp->md_cur = m;
mdp->md_pos = mtod(m, u_char*);
}
void
md_done(struct mdchain *mdp)
{
if (mdp->md_top) {
m_freem(mdp->md_top);
mdp->md_top = NULL;
}
}
/*
* Append a separate mbuf chain. It is caller responsibility to prevent
* multiple calls to fetch/record routines.
*/
void
md_append_record(struct mdchain *mdp, struct mbuf *top)
{
struct mbuf *m;
if (mdp->md_top == NULL) {
md_initm(mdp, top);
return;
}
m = mdp->md_top;
while (m->m_nextpkt)
m = m->m_nextpkt;
m->m_nextpkt = top;
top->m_nextpkt = NULL;
return;
}
/*
* Put next record in place of existing
*/
int
md_next_record(struct mdchain *mdp)
{
struct mbuf *m;
if (mdp->md_top == NULL)
return ENOENT;
m = mdp->md_top->m_nextpkt;
md_done(mdp);
if (m == NULL)
return ENOENT;
md_initm(mdp, m);
return 0;
}
int
md_get_uint8(struct mdchain *mdp, u_int8_t *x)
{
return md_get_mem(mdp, x, 1, MB_MINLINE);
}
int
md_get_uint16(struct mdchain *mdp, u_int16_t *x)
{
return md_get_mem(mdp, (caddr_t)x, 2, MB_MINLINE);
}
int
md_get_uint16le(struct mdchain *mdp, u_int16_t *x)
{
u_int16_t v;
int error = md_get_uint16(mdp, &v);
if (x != NULL)
*x = le16toh(v);
return error;
}
int
md_get_uint16be(struct mdchain *mdp, u_int16_t *x) {
u_int16_t v;
int error = md_get_uint16(mdp, &v);
if (x != NULL)
*x = be16toh(v);
return error;
}
int
md_get_uint32(struct mdchain *mdp, u_int32_t *x)
{
return md_get_mem(mdp, (caddr_t)x, 4, MB_MINLINE);
}
int
md_get_uint32be(struct mdchain *mdp, u_int32_t *x)
{
u_int32_t v;
int error;
error = md_get_uint32(mdp, &v);
if (x != NULL)
*x = be32toh(v);
return error;
}
int
md_get_uint32le(struct mdchain *mdp, u_int32_t *x)
{
u_int32_t v;
int error;
error = md_get_uint32(mdp, &v);
if (x != NULL)
*x = le32toh(v);
return error;
}
int
md_get_int64(struct mdchain *mdp, int64_t *x)
{
return md_get_mem(mdp, (caddr_t)x, 8, MB_MINLINE);
}
int
md_get_int64be(struct mdchain *mdp, int64_t *x)
{
int64_t v;
int error;
error = md_get_int64(mdp, &v);
if (x != NULL)
*x = be64toh(v);
return error;
}
int
md_get_int64le(struct mdchain *mdp, int64_t *x)
{
int64_t v;
int error;
error = md_get_int64(mdp, &v);
if (x != NULL)
*x = le64toh(v);
return error;
}
int
md_get_mem(struct mdchain *mdp, caddr_t target, int size, int type)
{
struct mbuf *m = mdp->md_cur;
int error;
u_int count;
u_char *s;
while (size > 0) {
if (m == NULL) {
MBERROR("incomplete copy\n");
return EBADRPC;
}
s = mdp->md_pos;
count = mtod(m, u_char*) + m->m_len - s;
if (count == 0) {
mdp->md_cur = m = m->m_next;
if (m)
s = mdp->md_pos = mtod(m, caddr_t);
continue;
}
if (count > size)
count = size;
size -= count;
mdp->md_pos += count;
if (target == NULL)
continue;
switch (type) {
case MB_MUSER:
error = copyout(s, target, count);
if (error)
return error;
break;
case MB_MSYSTEM:
bcopy(s, target, count);
break;
case MB_MINLINE:
while (count--)
*target++ = *s++;
continue;
}
target += count;
}
return 0;
}
int
md_get_mbuf(struct mdchain *mdp, int size, struct mbuf **ret)
{
struct mbuf *m = mdp->md_cur, *rm;
rm = m_copym(m, mdp->md_pos - mtod(m, u_char*), size, M_WAIT);
md_get_mem(mdp, NULL, size, MB_MZERO);
*ret = rm;
return 0;
}
int
md_get_uio(struct mdchain *mdp, struct uio *uiop, int size)
{
char *uiocp;
long left;
int mtype, error;
mtype = (uiop->uio_segflg == UIO_SYSSPACE) ? MB_MSYSTEM : MB_MUSER;
while (size > 0 && uiop->uio_resid) {
if (uiop->uio_iovcnt <= 0 || uiop->uio_iov == NULL)
return EFBIG;
left = uiop->uio_iov->iov_len;
if (left == 0) {
uiop->uio_iov++;
uiop->uio_iovcnt--;
continue;
}
uiocp = uiop->uio_iov->iov_base;
if (left > size)
left = size;
error = md_get_mem(mdp, uiocp, left, mtype);
if (error)
return error;
uiop->uio_offset += left;
uiop->uio_resid -= left;
uiop->uio_iov->iov_base =
(char *)uiop->uio_iov->iov_base + left;
uiop->uio_iov->iov_len -= left;
size -= left;
}
return 0;
}