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Diffstat (limited to 'static/netbsd/man9/pathbuf.9')
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diff --git a/static/netbsd/man9/pathbuf.9 b/static/netbsd/man9/pathbuf.9 new file mode 100644 index 00000000..8314958f --- /dev/null +++ b/static/netbsd/man9/pathbuf.9 @@ -0,0 +1,130 @@ +.\" $NetBSD: pathbuf.9,v 1.2 2010/11/30 10:32:46 dholland Exp $ +.\" +.\" Copyright (c) 2010 The NetBSD Foundation, Inc. +.\" All rights reserved. +.\" +.\" This code is derived from software contributed to The NetBSD Foundation +.\" by David A. Holland. +.\" +.\" 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. +.\" +.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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. +.\" +.Dd November 30, 2010 +.Dt PATHBUF 9 +.Os +.Sh NAME +.Nm pathbuf , +.Nm pathbuf_create , +.Nm pathbuf_assimilate , +.Nm pathbuf_copyin , +.Nm pathbuf_destroy +.Nd path buffer abstraction +.Sh SYNOPSIS +.In sys/namei.h +.Ft struct pathbuf * +.Fn pathbuf_create "const char *path" +.Ft struct pathbuf * +.Fn pathbuf_assimilate "char *pnbuf" +.Ft int +.Fn pathbuf_copyin "const char *userpath" "struct pathbuf **ret" +.Ft void +.Fn pathbuf_destroy "struct pathbuf *path" +.Sh DESCRIPTION +The +.Nm +interface is used to carry around pathnames. +This helps simplify the +.Xr namei 9 +interface. +A pathbuf should be thought of as a path name string combined with +whatever flags and metadata are needed to interpret it correctly. +It is an abstract type; the internals are hidden within the +.Xr namei 9 +implementation. +.Pp +The +.Fn pathbuf_create +function allocates and initializes a new pathbuf containing a copy of +the path string +.Fa path , +which should be a kernel pointer. +The return value should be checked for being +.Dv NULL +in case the system is out of memory. +Passing a path name larger than +.Dv PATH_MAX +will cause an assertion failure. +.Pp +The +.Fn pathbuf_copyin +function allocates and initializes a new pathbuf containing a path +string copied from user space with +.Xr copyinstr 9 . +It returns an error code. +.Pp +The +.Fn pathbuf_assimilate +function creates a pathbuf using the string buffer provided as +.Fa pnbuf . +This buffer must be of size +.Dv PATH_MAX +and must have been allocated with +.Fn PNBUF_GET . +The buffer is +.Dq taken over +by the returned pathbuf and will be released when the pathbuf is +destroyed. +Note: to avoid confusion and pointer bugs, +.Fn pathbuf_assimilate +should only be used where absolutely necessary; e.g. the NFS server +code uses it to generate pathbufs from strings fetched from mbufs. +.Pp +The +.Fn pathbuf_destroy +function deallocates a pathbuf. +Caution: because calling +.Xr namei 9 +loads pointers to memory belonging to the pathbuf into the nameidata +structure, a pathbuf should only be destroyed by the +.Fn namei +caller once all manipulations of the nameidata are complete. +.Pp +Also note that calling +.Fn namei +destroys the contents of the pathbuf. +Do not reuse a pathbuf for a second call to +.Fn namei . +.Sh CODE REFERENCES +The +.Nm +code is part of the name lookup code in +.Pa sys/kern/vfs_lookup.c . +.Sh SEE ALSO +.Xr namei 9 +.Sh BUGS +There are cases where it is necessary to get the path string left +behind after +.Fn namei +has run. +This produces an effect similar to +.Xr realpath 3 . +The interface for doing this is, for the time being, intentionally +undocumented and subject to change. |
