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Add missing descriptions of macros M_ALIGN and MH_ALIGN.

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Remove a reference to the defunct macro M_COPY_PKTHDR;
document the new functions m_dup_pkthdr() and m_move_pkthdr(),
and the macro variant of the latter, M_MOVE_PKTHDR().
This commit is contained in:
yar 2003-06-15 14:40:03 +00:00
parent e159c6524a
commit 18c9b0b6c2
1 changed files with 89 additions and 1 deletions
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90
share/man/man9/mbuf.9
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@ -60,13 +60,13 @@
.Fn mtod "struct mbuf *mbuf" "type"
.Ft int
.Fn MEXT_IS_REF "struct mbuf *mbuf"
.Fn M_COPY_PKTHDR "struct mbuf *to" "struct mbuf *from"
.Fn M_ALIGN "struct mbuf *mbuf" "u_int len"
.Fn MH_ALIGN "struct mbuf *mbuf" "u_int len"
.Ft int
.Fn M_LEADINGSPACE "struct mbuf *mbuf"
.Ft int
.Fn M_TRAILINGSPACE "struct mbuf *mbuf"
.Fn M_MOVE_PKTHDR "struct mbuf *to" "struct mbuf *from"
.Fn M_PREPEND "struct mbuf *mbuf" "int len" "int how"
.Fn MCHTYPE "struct mbuf *mbuf" "u_int type"
.Ft int
@ -115,6 +115,10 @@
.Fn m_cat "struct mbuf *m" "struct mbuf *n"
.Ft u_int
.Fn m_fixhdr "struct mbuf *mbuf"
.Ft void
.Fn m_dup_pkthdr "struct mbuf *to" "struct mbuf *from"
.Ft void
.Fn m_move_pkthdr "struct mbuf *to" "struct mbuf *from"
.Ft u_int
.Fn m_length "struct mbuf *mbuf" "struct mbuf **last"
.Ft struct mbuf *
@ -378,6 +382,40 @@ If the macro fails, the
.Dv M_EXT
flag won't be set in
.Fa mbuf .
.It Fn M_ALIGN mbuf len
Set the pointer
.Fa mbuf->m_data
to place an object of the size
.Fa len
at the end of the internal data area of
.Fa mbuf ,
long word aligned.
Applicable only if
.Fa mbuf
is newly allocated with
.Fn MGET
or
.Fn m_get .
.It Fn MH_ALIGN mbuf len
Serves the same purpose as
.Fn M_ALIGN
does, but only for
.Fa mbuf
newly allocated with
.Fn MGETHDR
or
.Fn m_gethdr ,
or initialized by
.Fn m_dup_pkthdr
or
.Fn m_move_pkthdr .
.It Fn M_LEADINGSPACE mbuf
Returns the number of bytes available before the beginning
of data in
.Fa mbuf .
.It Fn M_TRAILINGSPACE mbuf
Returns the number of bytes available after the end of data in
.Fa mbuf .
.It Fn M_PREPEND mbuf len how
This macro operates on an
.Vt mbuf chain .
@ -392,6 +430,9 @@ pointer or
is in
.Fa mbuf
after the call.
.It Fn M_MOVE_PKTHDR to from
Using this macro is equivalent to calling
.Fn m_move_pkthdr to from .
.It Fn M_WRITABLE mbuf
This macro will evaluate true if
.Fa mbuf
@ -415,6 +456,12 @@ argument to the
.Fn MEXTADD
macro, or can be directly set in individual
.Vt mbufs .
.It Fn MCHTYPE mbuf type
Change the type of
.Fa mbuf
to
.Fa type .
This is a relatively expensive operation and should be avoided.
.El
.Pp
The functions are:
@ -617,6 +664,47 @@ Return the length of the
and optionally a pointer to the last
.Vt mbuf .
.\"
.It Fn m_dup_pkthdr to from how
Upon the function's completion, the
.Vt mbuf
.Fa to
will contain an identical copy of
.Fa from->m_pkthdr
and the per-packet attributes found in the
.Vt mbuf chain
.Fa from .
The
.Vt mbuf
.Fa from
must have the flag
.Dv M_PKTHDR
initially set, and
.Fa to
must be empty on entry.
.\"
.It Fn m_move_pkthdr to from
Move
.Va m_pkthdr
and the per-packet attributes from the
.Vt mbuf chain
.Fa from
to the
.Vt mbuf
.Fa to .
The
.Vt mbuf
.Fa from
must have the flag
.Dv M_PKTHDR
initially set, and
.Fa to
must be empty on entry.
Upon the function's completion,
.Fa from
will have the flag
.Dv M_PKTHDR
and the per-packet attributes cleared.
.\"
.It Fn m_fixhdr buf
Set the packet-header length to the length of the
.Vt mbuf chain .