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authorzec <zec@FreeBSD.org>2009-05-05 10:56:12 +0000
committerzec <zec@FreeBSD.org>2009-05-05 10:56:12 +0000
commitd78a1b1a824c4f5eb8cb3583bb5265f73dcc24dd (patch)
tree79a0bccccf2c92504cdf23ad15f7c1813bb3f926 /sys/netgraph/netgraph.h
parent8e4ffe653f6c9ff6da3eed58566ef35e77d530d0 (diff)
downloadFreeBSD-src-d78a1b1a824c4f5eb8cb3583bb5265f73dcc24dd.zip
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Change the curvnet variable from a global const struct vnet *,
previously always pointing to the default vnet context, to a dynamically changing thread-local one. The currvnet context should be set on entry to networking code via CURVNET_SET() macros, and reverted to previous state via CURVNET_RESTORE(). Recursions on curvnet are permitted, though strongly discuouraged. This change should have no functional impact on nooptions VIMAGE kernel builds, where CURVNET_* macros expand to whitespace. The curthread->td_vnet (aka curvnet) variable's purpose is to be an indicator of the vnet context in which the current network-related operation takes place, in case we cannot deduce the current vnet context from any other source, such as by looking at mbuf's m->m_pkthdr.rcvif->if_vnet, sockets's so->so_vnet etc. Moreover, so far curvnet has turned out to be an invaluable consistency checking aid: it helps to catch cases when sockets, ifnets or any other vnet-aware structures may have leaked from one vnet to another. The exact placement of the CURVNET_SET() / CURVNET_RESTORE() macros was a result of an empirical iterative process, whith an aim to reduce recursions on CURVNET_SET() to a minimum, while still reducing the scope of CURVNET_SET() to networking only operations - the alternative would be calling CURVNET_SET() on each system call entry. In general, curvnet has to be set in three typicall cases: when processing socket-related requests from userspace or from within the kernel; when processing inbound traffic flowing from device drivers to upper layers of the networking stack, and when executing timer-driven networking functions. This change also introduces a DDB subcommand to show the list of all vnet instances. Approved by: julian (mentor)
Diffstat (limited to 'sys/netgraph/netgraph.h')
-rw-r--r--sys/netgraph/netgraph.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/sys/netgraph/netgraph.h b/sys/netgraph/netgraph.h
index e36234f..7276427 100644
--- a/sys/netgraph/netgraph.h
+++ b/sys/netgraph/netgraph.h
@@ -352,6 +352,7 @@ struct ng_node {
LIST_ENTRY(ng_node) nd_idnodes; /* ID hash collision list */
struct ng_queue nd_input_queue; /* input queue for locking */
int nd_refs; /* # of references to this node */
+ struct vnet *nd_vnet; /* network stack instance */
#ifdef NETGRAPH_DEBUG /*----------------------------------------------*/
#define ND_MAGIC 0x59264837
int nd_magic;
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