mbuf_tags.9 (137872) | mbuf_tags.9 (137953) |
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1.\" $OpenBSD: mbuf_tags.9,v 1.18 2003/12/08 07:07:35 mcbride Exp $ 2.\" 3.\" The authors of this man page are Angelos D. Keromytis 4.\" (angelos@cis.upenn.edu), Gleb Smirnoff <glebius@cell.sick.ru>, and 5.\" Robert Watson <rwatson@FreeBSD.org> 6.\" 7.\" Copyright (c) 2004 Robert N. M. Watson 8.\" Copyright (c) 2001 Angelos D. Keromytis --- 4 unchanged lines hidden (view full) --- 13.\" or modification of this software. 14.\" 15.\" THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 16.\" IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 17.\" REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 18.\" MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 19.\" PURPOSE. 20.\" | 1.\" $OpenBSD: mbuf_tags.9,v 1.18 2003/12/08 07:07:35 mcbride Exp $ 2.\" 3.\" The authors of this man page are Angelos D. Keromytis 4.\" (angelos@cis.upenn.edu), Gleb Smirnoff <glebius@cell.sick.ru>, and 5.\" Robert Watson <rwatson@FreeBSD.org> 6.\" 7.\" Copyright (c) 2004 Robert N. M. Watson 8.\" Copyright (c) 2001 Angelos D. Keromytis --- 4 unchanged lines hidden (view full) --- 13.\" or modification of this software. 14.\" 15.\" THIS SOFTWARE IS BEING PROVIDED "AS IS", WITHOUT ANY EXPRESS OR 16.\" IMPLIED WARRANTY. IN PARTICULAR, NONE OF THE AUTHORS MAKES ANY 17.\" REPRESENTATION OR WARRANTY OF ANY KIND CONCERNING THE 18.\" MERCHANTABILITY OF THIS SOFTWARE OR ITS FITNESS FOR ANY PARTICULAR 19.\" PURPOSE. 20.\" |
21.\" $FreeBSD: head/share/man/man9/mbuf_tags.9 137872 2004-11-18 23:01:07Z rwatson $ | 21.\" $FreeBSD: head/share/man/man9/mbuf_tags.9 137953 2004-11-21 00:24:21Z rwatson $ |
22.\" | 22.\" |
23.Dd May 20, 2004 | 23.Dd Nov 18, 2004 |
24.Dt MBUF_TAGS 9 25.Os 26.Sh NAME 27.Nm mbuf_tags 28.Nd a framework for generic packet attributes 29.Sh SYNOPSIS 30.In sys/mbuf.h 31.Ft "struct m_tag *" --- 29 unchanged lines hidden (view full) --- 61.Sh DESCRIPTION 62Mbuf tags allow additional meta-data to be associated with in-flight packets 63by providing a mechanism for the tagging of additional kernel memory onto 64packet header mbufs. 65Tags are maintained in chains off of the 66.Xr mbuf 9 67header, and maintained using a series of API calls to allocate, search, and 68delete tags. | 24.Dt MBUF_TAGS 9 25.Os 26.Sh NAME 27.Nm mbuf_tags 28.Nd a framework for generic packet attributes 29.Sh SYNOPSIS 30.In sys/mbuf.h 31.Ft "struct m_tag *" --- 29 unchanged lines hidden (view full) --- 61.Sh DESCRIPTION 62Mbuf tags allow additional meta-data to be associated with in-flight packets 63by providing a mechanism for the tagging of additional kernel memory onto 64packet header mbufs. 65Tags are maintained in chains off of the 66.Xr mbuf 9 67header, and maintained using a series of API calls to allocate, search, and 68delete tags. |
69Tags are identified using an ID and cookie that uniquely identifier a class | 69Tags are identified using an ID and cookie that uniquely identify a class |
70of data tagged onto the packet, and may contain an arbitrary amount of 71additional storage. 72Typical uses of mbuf tags include the storage of VLAN tags as described in 73.Xr vlan 4 , 74Mandatory Access Control (MAC) labels as described in 75.Xr mac 9 , 76IPsec policy information as described in 77.Xr ipsec 4 , 78and packet filter tags used by 79.Xr pf 4 . 80.Pp 81Tags will be maintained across a variety of operations, including the copying | 70of data tagged onto the packet, and may contain an arbitrary amount of 71additional storage. 72Typical uses of mbuf tags include the storage of VLAN tags as described in 73.Xr vlan 4 , 74Mandatory Access Control (MAC) labels as described in 75.Xr mac 9 , 76IPsec policy information as described in 77.Xr ipsec 4 , 78and packet filter tags used by 79.Xr pf 4 . 80.Pp 81Tags will be maintained across a variety of operations, including the copying |
82of packet headers using facilities such as M_COPY_PKTHDR and M_MOVE_PKTHDR. | 82of packet headers using facilities such as 83.Fn M_COPY_PKTHDR 84and 85.Fn M_MOVE_PKTHDR . |
83Any tags associated with an mbuf header will be automatically freed when the 84mbuf is freed, although some subsystems will wish to delete the tags prior 85to that time. 86.Pp 87Packet tags are used by different kernel APIs 88to keep track of operations done or 89scheduled to happen to packets. 90Each packet tag can be distinguished by its type and cookie. --- 192 unchanged lines hidden --- | 86Any tags associated with an mbuf header will be automatically freed when the 87mbuf is freed, although some subsystems will wish to delete the tags prior 88to that time. 89.Pp 90Packet tags are used by different kernel APIs 91to keep track of operations done or 92scheduled to happen to packets. 93Each packet tag can be distinguished by its type and cookie. --- 192 unchanged lines hidden --- |