adds a description of m_apply

closes PR kern/26059
has been looked at by Jason Thorpe and Christos Zoulas
This commit is contained in:
spz 2004-12-12 21:04:16 +00:00
parent 964859d895
commit 3ca52e72db
1 changed files with 33 additions and 2 deletions

View File

@ -1,4 +1,4 @@
.\" $NetBSD: mbuf.9,v 1.30 2004/09/06 16:25:29 wiz Exp $
.\" $NetBSD: mbuf.9,v 1.31 2004/12/12 21:04:16 spz Exp $
.\"
.\" Copyright (c) 1997 The NetBSD Foundation, Inc.
.\" All rights reserved.
@ -34,7 +34,7 @@
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd September 6, 2004
.Dd December 12, 2004
.Dt MBUF 9
.Os
.Sh NAME
@ -56,6 +56,7 @@
.Nm m_pullup ,
.Nm m_split ,
.Nm m_adj ,
.Nm m_apply ,
.Nm m_free ,
.Nm m_freem ,
.Nm mtod ,
@ -112,6 +113,8 @@
.Fn m_split "struct mbuf *m0" "int len0" "int wait"
.Ft void
.Fn m_adj "struct mbuf *mp" "int req_len"
.Ft int
.Fn m_apply "struct mbuf *m" "int off" "int len" "int *f(void *, caddr_t, unsigned int)" "void *arg"
.Ft struct mbuf *
.Fn m_free "struct mbuf *m"
.Ft void
@ -508,6 +511,34 @@ from the back (and if it is zero, the mbuf will stay bearded).
This function does not move data in any way, but is used to manipulate the
data area pointer and data length variable of the mbuf in a non-clobbering
way.
.It Fn m_apply "struct mbuf *m" "int off" "int len" "int (*f)(void *, caddr_t, unsigned int)" "void *arg"
Apply function
.Fa f
to the data in an mbuf chain starting
.Fa off
bytes from the beginning, continuing for
.Fa len
bytes. Neither
.Fa off
nor
.Fa len
may be negative.
.Fa arg
will be supplied as first argument for
.Fa f ,
the second argument will be the pointer to the data buffer of a
packet (starting after
.Fa off
bytes in the stream), and the third argument is the amount
of data in bytes in this call. If
.Fa f
returns something not equal to
.Dv zero
.Fn m_apply
will bail out, returning the return code of
.Fa f .
Upon successful completion it will return
.Dv zero .
.It Fn m_free "struct mbuf *m"
Frees mbuf
.Fa m .