diff options
Diffstat (limited to 'sys/fs/procfs/procfs_vnops.c')
| -rw-r--r-- | sys/fs/procfs/procfs_vnops.c | 814 |
1 files changed, 814 insertions, 0 deletions
diff --git a/sys/fs/procfs/procfs_vnops.c b/sys/fs/procfs/procfs_vnops.c new file mode 100644 index 0000000..4e1ee00 --- /dev/null +++ b/sys/fs/procfs/procfs_vnops.c @@ -0,0 +1,814 @@ +/* + * Copyright (c) 1993 Jan-Simon Pendry + * Copyright (c) 1993 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Jan-Simon Pendry. + * + * 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. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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. + * + * @(#)procfs_vnops.c 8.6 (Berkeley) 2/7/94 + * + * From: + * $Id: procfs_vnops.c,v 3.2 1993/12/15 09:40:17 jsp Exp $ + */ + +/* + * procfs vnode interface + */ + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/time.h> +#include <sys/kernel.h> +#include <sys/file.h> +#include <sys/proc.h> +#include <sys/vnode.h> +#include <sys/namei.h> +#include <sys/malloc.h> +#include <sys/dirent.h> +#include <sys/resourcevar.h> +#include <miscfs/procfs/procfs.h> +#include <vm/vm.h> /* for PAGE_SIZE */ + +/* + * Vnode Operations. + * + */ + +/* + * This is a list of the valid names in the + * process-specific sub-directories. It is + * used in procfs_lookup and procfs_readdir + */ +static struct pfsnames { + u_short d_namlen; + char d_name[PROCFS_NAMELEN]; + pfstype d_pfstype; +} procent[] = { +#define N(s) sizeof(s)-1, s + /* namlen, nam, type */ + { N("file"), Pfile }, + { N("mem"), Pmem }, + { N("regs"), Pregs }, + { N("fpregs"), Pfpregs }, + { N("ctl"), Pctl }, + { N("status"), Pstatus }, + { N("note"), Pnote }, + { N("notepg"), Pnotepg }, +#undef N +}; +#define Nprocent (sizeof(procent)/sizeof(procent[0])) + +static pid_t atopid __P((const char *, u_int)); + +/* + * set things up for doing i/o on + * the pfsnode (vp). (vp) is locked + * on entry, and should be left locked + * on exit. + * + * for procfs we don't need to do anything + * in particular for i/o. all that is done + * is to support exclusive open on process + * memory images. + */ +procfs_open(ap) + struct vop_open_args *ap; +{ + struct pfsnode *pfs = VTOPFS(ap->a_vp); + + switch (pfs->pfs_type) { + case Pmem: + if (PFIND(pfs->pfs_pid) == 0) + return (ENOENT); /* was ESRCH, jsp */ + + if ((pfs->pfs_flags & FWRITE) && (ap->a_mode & O_EXCL) || + (pfs->pfs_flags & O_EXCL) && (ap->a_mode & FWRITE)) + return (EBUSY); + + + if (ap->a_mode & FWRITE) + pfs->pfs_flags = ap->a_mode & (FWRITE|O_EXCL); + + return (0); + + default: + break; + } + + return (0); +} + +/* + * close the pfsnode (vp) after doing i/o. + * (vp) is not locked on entry or exit. + * + * nothing to do for procfs other than undo + * any exclusive open flag (see _open above). + */ +procfs_close(ap) + struct vop_close_args *ap; +{ + struct pfsnode *pfs = VTOPFS(ap->a_vp); + + switch (pfs->pfs_type) { + case Pmem: + if ((ap->a_fflag & FWRITE) && (pfs->pfs_flags & O_EXCL)) + pfs->pfs_flags &= ~(FWRITE|O_EXCL); + break; + } + + return (0); +} + +/* + * do an ioctl operation on pfsnode (vp). + * (vp) is not locked on entry or exit. + */ +procfs_ioctl(ap) + struct vop_ioctl_args *ap; +{ + + return (ENOTTY); +} + +/* + * do block mapping for pfsnode (vp). + * since we don't use the buffer cache + * for procfs this function should never + * be called. in any case, it's not clear + * what part of the kernel ever makes use + * of this function. for sanity, this is the + * usual no-op bmap, although returning + * (EIO) would be a reasonable alternative. + */ +procfs_bmap(ap) + struct vop_bmap_args *ap; +{ + + if (ap->a_vpp != NULL) + *ap->a_vpp = ap->a_vp; + if (ap->a_bnp != NULL) + *ap->a_bnp = ap->a_bn; + return (0); +} + +/* + * _inactive is called when the pfsnode + * is vrele'd and the reference count goes + * to zero. (vp) will be on the vnode free + * list, so to get it back vget() must be + * used. + * + * for procfs, check if the process is still + * alive and if it isn't then just throw away + * the vnode by calling vgone(). this may + * be overkill and a waste of time since the + * chances are that the process will still be + * there and PFIND is not free. + * + * (vp) is not locked on entry or exit. + */ +procfs_inactive(ap) + struct vop_inactive_args *ap; +{ + struct pfsnode *pfs = VTOPFS(ap->a_vp); + + if (PFIND(pfs->pfs_pid) == 0) + vgone(ap->a_vp); + + return (0); +} + +/* + * _reclaim is called when getnewvnode() + * wants to make use of an entry on the vnode + * free list. at this time the filesystem needs + * to free any private data and remove the node + * from any private lists. + */ +procfs_reclaim(ap) + struct vop_reclaim_args *ap; +{ + int error; + + error = procfs_freevp(ap->a_vp); + return (error); +} + +/* + * Return POSIX pathconf information applicable to special devices. + */ +procfs_pathconf(ap) + struct vop_pathconf_args /* { + struct vnode *a_vp; + int a_name; + int *a_retval; + } */ *ap; +{ + + switch (ap->a_name) { + case _PC_LINK_MAX: + *ap->a_retval = LINK_MAX; + return (0); + case _PC_MAX_CANON: + *ap->a_retval = MAX_CANON; + return (0); + case _PC_MAX_INPUT: + *ap->a_retval = MAX_INPUT; + return (0); + case _PC_PIPE_BUF: + *ap->a_retval = PIPE_BUF; + return (0); + case _PC_CHOWN_RESTRICTED: + *ap->a_retval = 1; + return (0); + case _PC_VDISABLE: + *ap->a_retval = _POSIX_VDISABLE; + return (0); + default: + return (EINVAL); + } + /* NOTREACHED */ +} + +/* + * _print is used for debugging. + * just print a readable description + * of (vp). + */ +procfs_print(ap) + struct vop_print_args *ap; +{ + struct pfsnode *pfs = VTOPFS(ap->a_vp); + + printf("tag VT_PROCFS, pid %d, mode %x, flags %x\n", + pfs->pfs_pid, + pfs->pfs_mode, pfs->pfs_flags); +} + +/* + * _abortop is called when operations such as + * rename and create fail. this entry is responsible + * for undoing any side-effects caused by the lookup. + * this will always include freeing the pathname buffer. + */ +procfs_abortop(ap) + struct vop_abortop_args *ap; +{ + + if ((ap->a_cnp->cn_flags & (HASBUF | SAVESTART)) == HASBUF) + FREE(ap->a_cnp->cn_pnbuf, M_NAMEI); + return (0); +} + +/* + * generic entry point for unsupported operations + */ +procfs_badop() +{ + + return (EIO); +} + +/* + * Invent attributes for pfsnode (vp) and store + * them in (vap). + * Directories lengths are returned as zero since + * any real length would require the genuine size + * to be computed, and nothing cares anyway. + * + * this is relatively minimal for procfs. + */ +procfs_getattr(ap) + struct vop_getattr_args *ap; +{ + struct pfsnode *pfs = VTOPFS(ap->a_vp); + struct vattr *vap = ap->a_vap; + struct proc *procp; + int error; + + /* first check the process still exists */ + switch (pfs->pfs_type) { + case Proot: + procp = 0; + break; + + default: + procp = PFIND(pfs->pfs_pid); + if (procp == 0) + return (ENOENT); + } + + error = 0; + + /* start by zeroing out the attributes */ + VATTR_NULL(vap); + + /* next do all the common fields */ + vap->va_type = ap->a_vp->v_type; + vap->va_mode = pfs->pfs_mode; + vap->va_fileid = pfs->pfs_fileno; + vap->va_flags = 0; + vap->va_blocksize = PAGE_SIZE; + vap->va_bytes = vap->va_size = 0; + + /* + * If the process has exercised some setuid or setgid + * privilege, then rip away read/write permission so + * that only root can gain access. + */ + switch (pfs->pfs_type) { + case Pregs: + case Pfpregs: + case Pmem: + if (procp->p_flag & P_SUGID) + vap->va_mode &= ~((VREAD|VWRITE)| + ((VREAD|VWRITE)>>3)| + ((VREAD|VWRITE)>>6)); + break; + } + + /* + * Make all times be current TOD. + * It would be possible to get the process start + * time from the p_stat structure, but there's + * no "file creation" time stamp anyway, and the + * p_stat structure is not addressible if u. gets + * swapped out for that process. + */ + microtime(&vap->va_ctime); + vap->va_atime = vap->va_mtime = vap->va_ctime; + + /* + * now do the object specific fields + * + * The size could be set from struct reg, but it's hardly + * worth the trouble, and it puts some (potentially) machine + * dependent data into this machine-independent code. If it + * becomes important then this function should break out into + * a per-file stat function in the corresponding .c file. + */ + + switch (pfs->pfs_type) { + case Proot: + vap->va_nlink = 2; + vap->va_uid = 0; + vap->va_gid = 0; + break; + + case Pproc: + vap->va_nlink = 2; + vap->va_uid = procp->p_ucred->cr_uid; + vap->va_gid = procp->p_ucred->cr_gid; + break; + + case Pfile: + error = EOPNOTSUPP; + break; + + case Pmem: + vap->va_nlink = 1; + vap->va_bytes = vap->va_size = + ctob(procp->p_vmspace->vm_tsize + + procp->p_vmspace->vm_dsize + + procp->p_vmspace->vm_ssize); + vap->va_uid = procp->p_ucred->cr_uid; + vap->va_gid = procp->p_ucred->cr_gid; + break; + + case Pregs: + case Pfpregs: + case Pctl: + case Pstatus: + case Pnote: + case Pnotepg: + vap->va_nlink = 1; + vap->va_uid = procp->p_ucred->cr_uid; + vap->va_gid = procp->p_ucred->cr_gid; + break; + + default: + panic("procfs_getattr"); + } + + return (error); +} + +procfs_setattr(ap) + struct vop_setattr_args *ap; +{ + /* + * just fake out attribute setting + * it's not good to generate an error + * return, otherwise things like creat() + * will fail when they try to set the + * file length to 0. worse, this means + * that echo $note > /proc/$pid/note will fail. + */ + + return (0); +} + +/* + * implement access checking. + * + * something very similar to this code is duplicated + * throughout the 4bsd kernel and should be moved + * into kern/vfs_subr.c sometime. + * + * actually, the check for super-user is slightly + * broken since it will allow read access to write-only + * objects. this doesn't cause any particular trouble + * but does mean that the i/o entry points need to check + * that the operation really does make sense. + */ +procfs_access(ap) + struct vop_access_args *ap; +{ + struct vattr *vap; + struct vattr vattr; + int error; + + /* + * If you're the super-user, + * you always get access. + */ + if (ap->a_cred->cr_uid == (uid_t) 0) + return (0); + vap = &vattr; + if (error = VOP_GETATTR(ap->a_vp, vap, ap->a_cred, ap->a_p)) + return (error); + + /* + * Access check is based on only one of owner, group, public. + * If not owner, then check group. If not a member of the + * group, then check public access. + */ + if (ap->a_cred->cr_uid != vap->va_uid) { + gid_t *gp; + int i; + + (ap->a_mode) >>= 3; + gp = ap->a_cred->cr_groups; + for (i = 0; i < ap->a_cred->cr_ngroups; i++, gp++) + if (vap->va_gid == *gp) + goto found; + ap->a_mode >>= 3; +found: + ; + } + + if ((vap->va_mode & ap->a_mode) == ap->a_mode) + return (0); + + return (EACCES); +} + +/* + * lookup. this is incredibly complicated in the + * general case, however for most pseudo-filesystems + * very little needs to be done. + * + * unless you want to get a migraine, just make sure your + * filesystem doesn't do any locking of its own. otherwise + * read and inwardly digest ufs_lookup(). + */ +procfs_lookup(ap) + struct vop_lookup_args *ap; +{ + struct componentname *cnp = ap->a_cnp; + struct vnode **vpp = ap->a_vpp; + struct vnode *dvp = ap->a_dvp; + char *pname = cnp->cn_nameptr; + int error = 0; + pid_t pid; + struct vnode *nvp; + struct pfsnode *pfs; + struct proc *procp; + pfstype pfs_type; + int i; + + if (cnp->cn_namelen == 1 && *pname == '.') { + *vpp = dvp; + VREF(dvp); + /*VOP_LOCK(dvp);*/ + return (0); + } + + *vpp = NULL; + + pfs = VTOPFS(dvp); + switch (pfs->pfs_type) { + case Proot: + if (cnp->cn_flags & ISDOTDOT) + return (EIO); + + if (CNEQ(cnp, "curproc", 7)) + pid = cnp->cn_proc->p_pid; + else + pid = atopid(pname, cnp->cn_namelen); + if (pid == NO_PID) + return (ENOENT); + + procp = PFIND(pid); + if (procp == 0) + return (ENOENT); + + error = procfs_allocvp(dvp->v_mount, &nvp, pid, Pproc); + if (error) + return (error); + + nvp->v_type = VDIR; + pfs = VTOPFS(nvp); + + *vpp = nvp; + return (0); + + case Pproc: + if (cnp->cn_flags & ISDOTDOT) { + error = procfs_root(dvp->v_mount, vpp); + return (error); + } + + procp = PFIND(pfs->pfs_pid); + if (procp == 0) + return (ENOENT); + + for (i = 0; i < Nprocent; i++) { + struct pfsnames *dp = &procent[i]; + + if (cnp->cn_namelen == dp->d_namlen && + bcmp(pname, dp->d_name, dp->d_namlen) == 0) { + pfs_type = dp->d_pfstype; + goto found; + } + } + return (ENOENT); + + found: + if (pfs_type == Pfile) { + nvp = procfs_findtextvp(procp); + if (nvp) { + VREF(nvp); + VOP_LOCK(nvp); + } else { + error = ENXIO; + } + } else { + error = procfs_allocvp(dvp->v_mount, &nvp, + pfs->pfs_pid, pfs_type); + if (error) + return (error); + + nvp->v_type = VREG; + pfs = VTOPFS(nvp); + } + *vpp = nvp; + return (error); + + default: + return (ENOTDIR); + } +} + +/* + * readdir returns directory entries from pfsnode (vp). + * + * the strategy here with procfs is to generate a single + * directory entry at a time (struct pfsdent) and then + * copy that out to userland using uiomove. a more efficent + * though more complex implementation, would try to minimize + * the number of calls to uiomove(). for procfs, this is + * hardly worth the added code complexity. + * + * this should just be done through read() + */ +procfs_readdir(ap) + struct vop_readdir_args *ap; +{ + struct uio *uio = ap->a_uio; + struct pfsdent d; + struct pfsdent *dp = &d; + struct pfsnode *pfs; + int error; + int count; + int i; + + pfs = VTOPFS(ap->a_vp); + + if (uio->uio_resid < UIO_MX) + return (EINVAL); + if (uio->uio_offset & (UIO_MX-1)) + return (EINVAL); + if (uio->uio_offset < 0) + return (EINVAL); + + error = 0; + count = 0; + i = uio->uio_offset / UIO_MX; + + switch (pfs->pfs_type) { + /* + * this is for the process-specific sub-directories. + * all that is needed to is copy out all the entries + * from the procent[] table (top of this file). + */ + case Pproc: { + while (uio->uio_resid >= UIO_MX) { + struct pfsnames *dt; + + if (i >= Nprocent) + break; + + dt = &procent[i]; + + dp->d_reclen = UIO_MX; + dp->d_fileno = PROCFS_FILENO(pfs->pfs_pid, dt->d_pfstype); + dp->d_type = DT_REG; + dp->d_namlen = dt->d_namlen; + bcopy(dt->d_name, dp->d_name, sizeof(dt->d_name)-1); + error = uiomove((caddr_t) dp, UIO_MX, uio); + if (error) + break; + count += UIO_MX; + i++; + } + + break; + + } + + /* + * this is for the root of the procfs filesystem + * what is needed is a special entry for "curproc" + * followed by an entry for each process on allproc +#ifdef PROCFS_ZOMBIE + * and zombproc. +#endif + */ + + case Proot: { + int pcnt; +#ifdef PROCFS_ZOMBIE + int doingzomb = 0; +#endif + volatile struct proc *p; + + p = allproc; + +#define PROCFS_XFILES 1 /* number of other entries, like "curproc" */ + pcnt = PROCFS_XFILES; + + while (p && uio->uio_resid >= UIO_MX) { + bzero((char *) dp, UIO_MX); + dp->d_type = DT_DIR; + dp->d_reclen = UIO_MX; + + switch (i) { + case 0: + /* ship out entry for "curproc" */ + dp->d_fileno = PROCFS_FILENO(PID_MAX+1, Pproc); + dp->d_namlen = sprintf(dp->d_name, "curproc"); + break; + + default: + if (pcnt >= i) { + dp->d_fileno = PROCFS_FILENO(p->p_pid, Pproc); + dp->d_namlen = sprintf(dp->d_name, "%ld", (long) p->p_pid); + } + + p = p->p_next; + +#ifdef PROCFS_ZOMBIE + if (p == 0 && doingzomb == 0) { + doingzomb = 1; + p = zombproc; + } +#endif + + if (pcnt++ < i) + continue; + + break; + } + error = uiomove((caddr_t) dp, UIO_MX, uio); + if (error) + break; + count += UIO_MX; + i++; + } + + break; + + } + + default: + error = ENOTDIR; + break; + } + + uio->uio_offset = i * UIO_MX; + + return (error); +} + +/* + * convert decimal ascii to pid_t + */ +static pid_t +atopid(b, len) + const char *b; + u_int len; +{ + pid_t p = 0; + + while (len--) { + char c = *b++; + if (c < '0' || c > '9') + return (NO_PID); + p = 10 * p + (c - '0'); + if (p > PID_MAX) + return (NO_PID); + } + + return (p); +} + +/* + * procfs vnode operations. + */ +int (**procfs_vnodeop_p)(); +struct vnodeopv_entry_desc procfs_vnodeop_entries[] = { + { &vop_default_desc, vn_default_error }, + { &vop_lookup_desc, procfs_lookup }, /* lookup */ + { &vop_create_desc, procfs_create }, /* create */ + { &vop_mknod_desc, procfs_mknod }, /* mknod */ + { &vop_open_desc, procfs_open }, /* open */ + { &vop_close_desc, procfs_close }, /* close */ + { &vop_access_desc, procfs_access }, /* access */ + { &vop_getattr_desc, procfs_getattr }, /* getattr */ + { &vop_setattr_desc, procfs_setattr }, /* setattr */ + { &vop_read_desc, procfs_read }, /* read */ + { &vop_write_desc, procfs_write }, /* write */ + { &vop_ioctl_desc, procfs_ioctl }, /* ioctl */ + { &vop_select_desc, procfs_select }, /* select */ + { &vop_mmap_desc, procfs_mmap }, /* mmap */ + { &vop_fsync_desc, procfs_fsync }, /* fsync */ + { &vop_seek_desc, procfs_seek }, /* seek */ + { &vop_remove_desc, procfs_remove }, /* remove */ + { &vop_link_desc, procfs_link }, /* link */ + { &vop_rename_desc, procfs_rename }, /* rename */ + { &vop_mkdir_desc, procfs_mkdir }, /* mkdir */ + { &vop_rmdir_desc, procfs_rmdir }, /* rmdir */ + { &vop_symlink_desc, procfs_symlink }, /* symlink */ + { &vop_readdir_desc, procfs_readdir }, /* readdir */ + { &vop_readlink_desc, procfs_readlink }, /* readlink */ + { &vop_abortop_desc, procfs_abortop }, /* abortop */ + { &vop_inactive_desc, procfs_inactive }, /* inactive */ + { &vop_reclaim_desc, procfs_reclaim }, /* reclaim */ + { &vop_lock_desc, procfs_lock }, /* lock */ + { &vop_unlock_desc, procfs_unlock }, /* unlock */ + { &vop_bmap_desc, procfs_bmap }, /* bmap */ + { &vop_strategy_desc, procfs_strategy }, /* strategy */ + { &vop_print_desc, procfs_print }, /* print */ + { &vop_islocked_desc, procfs_islocked }, /* islocked */ + { &vop_pathconf_desc, procfs_pathconf }, /* pathconf */ + { &vop_advlock_desc, procfs_advlock }, /* advlock */ + { &vop_blkatoff_desc, procfs_blkatoff }, /* blkatoff */ + { &vop_valloc_desc, procfs_valloc }, /* valloc */ + { &vop_vfree_desc, procfs_vfree }, /* vfree */ + { &vop_truncate_desc, procfs_truncate }, /* truncate */ + { &vop_update_desc, procfs_update }, /* update */ + { (struct vnodeop_desc*)NULL, (int(*)())NULL } +}; +struct vnodeopv_desc procfs_vnodeop_opv_desc = + { &procfs_vnodeop_p, procfs_vnodeop_entries }; |
