1.\" $NetBSD: p2k.3,v 1.13 2024/10/13 14:56:30 rillig Exp $ 2.\" 3.\" Copyright (c) 2008 Antti Kantee. All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.Dd October 13, 2024 27.Dt P2K 3 28.Os 29.Sh NAME 30.Nm p2k 31.Nd puffs to kernel vfs translation library 32.Sh LIBRARY 33p2k Library (libp2k, \-lp2k) 34.Sh SYNOPSIS 35.In rump/p2k.h 36.Ft struct p2k_mount * 37.Fn p2k_init "uint32_t puffs_flags" 38.Ft void 39.Fn p2k_cancel "struct p2k_mount *p2m" "int error" 40.Ft int 41.Fo p2k_setup_fs 42.Fa "struct p2k_mount *p2m" "const char *vfsname" "const char *devpath" 43.Fa "const char *mountpath" "int mntflags" "void *arg" "size_t alen" 44.Fc 45.Ft int 46.Fo p2k_setup_diskfs 47.Fa "struct p2k_mount *p2m" "const char *vfsname" "const char *devpath" 48.Fa "struct ukfs_part *part" "const char *mountpath" "int mntflags" 49.Fa "void *arg" "size_t alen" 50.Fc 51.Ft int 52.Fn p2k_mainloop "struct p2k_mount *p2m" 53.Ft int 54.Fo p2k_run_fs 55.Fa "const char *vfsname" "const char *devpath" "const char *mountpath" 56.Fa "int mntflags" "void *arg" "size_t alen" "uint32_t puffs_flags" 57.Fc 58.Ft int 59.Fo p2k_run_diskfs 60.Fa "const char *vfsname" "const char *devpath" "struct ukfs_part *part" 61.Fa "const char *mountpath" "int mntflags" "void *arg" "size_t alen" 62.Fa "uint32_t puffs_flags" 63.Fc 64.Sh DESCRIPTION 65The 66.Nm 67library translates the puffs protocol to the kernel 68.Xr vfs 9 69protocol and back again. 70It can therefore be used to mount and run kernel file system code as 71a userspace daemon. 72.Pp 73Calling the library interface function mounts the file system and, 74if successful, starts handling requests. 75The parameters are handled by 76.Fn ukfs_mount 77(see 78.Xr ukfs 3 ) , 79with the exception that 80.Fa mountpath 81and 82.Fa puffs_flags 83are handled by 84.Xr puffs 3 . 85The "run_fs" variants of the interfaces are provided as a convenience 86for the common case. 87They execute all of init, setup and mainloop in one call. 88.Sh ENVIRONMENT 89The following environment variables affect the behaviour of 90.Nm . 91They are useful mostly for debugging purposes. 92The flags are environment variables because typically the command line 93arguments to 94.Nm 95utilities are parsed using versions not aware of 96.Nm 97options; for example, the 98.Xr rump_cd9660 8 99arguments are really parsed by 100.Xr mount_cd9660 8 . 101.Bl -tag -width "XP2K_NOCACHE_PAGE" -offset 2n 102.It Dv P2K_DEBUG 103Do not detach from tty and print information about each puffs operation. 104In case the daemon receives 105.Dv SIGINFO 106(typically from ctrl-T), it dumps out the status of the mount point. 107Sending 108.Dv SIGUSR1 109causes a dump of all the vnodes (verbose). 110.It Dv P2K_NODETACH 111Do not detach from tty. 112.It Dv P2K_NOCACHE_PAGE 113Do not use the puffs page cache. 114.It Dv P2K_NOCACHE_NAME 115Do not use the puffs name cache. 116.It Dv P2K_NOCACHE 117Do not use the puffs page or name cache. 118.It Dv P2K_WIZARDUID 119If set, use the value of the variable to determine the UID of the 120caller of each operation instead of the actual caller supplied by 121.Xr puffs 3 . 122This can be used for example to simplify modifying an OS installation's 123root image as a non-root user. 124.El 125.Sh SEE ALSO 126.Xr puffs 3 , 127.Xr rump 3 , 128.Xr ukfs 3 , 129.Xr rump_cd9660 8 , 130.Xr rump_efs 8 , 131.Xr rump_ext2fs 8 , 132.Xr rump_ffs 8 , 133.Xr rump_hfs 8 , 134.Xr rump_lfs 8 , 135.Xr rump_msdos 8 , 136.Xr rump_nfs 8 , 137.Xr rump_ntfs 8 , 138.Xr rump_syspuffs 8 , 139.Xr rump_sysvbfs 8 , 140.Xr rump_tmpfs 8 , 141.Xr rump_udf 8 142