/* * Copyright (c) 1993, 1995 Jan-Simon Pendry * Copyright (c) 1993, 1995 * 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. 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 8.18 (Berkeley) 5/21/95 * * $FreeBSD: src/sys/miscfs/procfs/procfs_vnops.c,v 1.76.2.7 2002/01/22 17:22:59 nectar Exp $ */ /* * procfs vnode interface */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static int procfs_access (struct vop_access_args *); static int procfs_badop (struct vop_generic_args *); static int procfs_bmap (struct vop_bmap_args *); static int procfs_close (struct vop_close_args *); static int procfs_getattr (struct vop_getattr_args *); static int procfs_inactive (struct vop_inactive_args *); static int procfs_ioctl (struct vop_ioctl_args *); static int procfs_kqfilter (struct vop_kqfilter_args *); static int procfs_lookup (struct vop_old_lookup_args *); static int procfs_open (struct vop_open_args *); static int procfs_print (struct vop_print_args *); static int procfs_readdir (struct vop_readdir_args *); static int procfs_readlink (struct vop_readlink_args *); static int procfs_reclaim (struct vop_reclaim_args *); static int procfs_setattr (struct vop_setattr_args *); static int procfs_readdir_proc(struct vop_readdir_args *); static int procfs_readdir_root(struct vop_readdir_args *); /* * procfs vnode operations. */ struct vop_ops procfs_vnode_vops = { .vop_default = vop_defaultop, .vop_access = procfs_access, .vop_advlock = (void *)procfs_badop, .vop_bmap = procfs_bmap, .vop_close = procfs_close, .vop_old_create = (void *)procfs_badop, .vop_getattr = procfs_getattr, .vop_inactive = procfs_inactive, .vop_old_link = (void *)procfs_badop, .vop_old_lookup = procfs_lookup, .vop_old_mkdir = (void *)procfs_badop, .vop_old_mknod = (void *)procfs_badop, .vop_open = procfs_open, .vop_pathconf = vop_stdpathconf, .vop_print = procfs_print, .vop_read = procfs_rw, .vop_readdir = procfs_readdir, .vop_readlink = procfs_readlink, .vop_reclaim = procfs_reclaim, .vop_old_remove = (void *)procfs_badop, .vop_old_rename = (void *)procfs_badop, .vop_old_rmdir = (void *)procfs_badop, .vop_setattr = procfs_setattr, .vop_old_symlink = (void *)procfs_badop, .vop_write = (void *)procfs_rw, .vop_ioctl = procfs_ioctl, .vop_kqfilter = procfs_kqfilter, }; /* * 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 proc_target { u_char pt_type; u_char pt_namlen; char *pt_name; pfstype pt_pfstype; int (*pt_valid) (struct lwp *p); } proc_targets[] = { #define N(s) sizeof(s)-1, s /* name type validp */ { DT_DIR, N("."), Pproc, NULL }, { DT_DIR, N(".."), Proot, NULL }, { DT_REG, N("mem"), Pmem, NULL }, { DT_REG, N("regs"), Pregs, procfs_validregs }, { DT_REG, N("fpregs"), Pfpregs, procfs_validfpregs }, { DT_REG, N("dbregs"), Pdbregs, procfs_validdbregs }, { DT_REG, N("ctl"), Pctl, NULL }, { DT_REG, N("status"), Pstatus, NULL }, { DT_REG, N("note"), Pnote, NULL }, { DT_REG, N("notepg"), Pnotepg, NULL }, { DT_REG, N("map"), Pmap, procfs_validmap }, { DT_REG, N("etype"), Ptype, procfs_validtype }, { DT_REG, N("cmdline"), Pcmdline, NULL }, { DT_REG, N("rlimit"), Prlimit, NULL }, { DT_LNK, N("file"), Pfile, NULL }, { DT_LNK, N("exe"), Pfile, NULL }, #undef N }; static const int nproc_targets = NELEM(proc_targets); static pid_t atopid (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(struct vnode *a_vp, int a_mode, struct ucred *a_cred, * struct file *a_fp) */ static int procfs_open(struct vop_open_args *ap) { struct pfsnode *pfs = VTOPFS(ap->a_vp); struct proc *p1, *p2; int error; p2 = pfs_pfind(pfs->pfs_pid); if (p2 == NULL) return (ENOENT); if (pfs->pfs_pid && !PRISON_CHECK(ap->a_cred, p2->p_ucred)) { error = ENOENT; goto done; } switch (pfs->pfs_type) { case Pmem: if (((pfs->pfs_flags & FWRITE) && (ap->a_mode & O_EXCL)) || ((pfs->pfs_flags & O_EXCL) && (ap->a_mode & FWRITE))) { error = EBUSY; goto done; } p1 = curproc; KKASSERT(p1); /* Can't trace a process that's currently exec'ing. */ if ((p2->p_flags & P_INEXEC) != 0) { error = EAGAIN; goto done; } if (!CHECKIO(p1, p2) || p_trespass(ap->a_cred, p2->p_ucred)) { error = EPERM; goto done; } if (ap->a_mode & FWRITE) pfs->pfs_flags = ap->a_mode & (FWRITE|O_EXCL); break; default: break; } error = vop_stdopen(ap); done: pfs_pdone(p2); return error; } /* * 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(struct vnode *a_vp, int a_fflag, struct ucred *a_cred) */ static int procfs_close(struct vop_close_args *ap) { struct pfsnode *pfs = VTOPFS(ap->a_vp); struct proc *p; /* * Make sure the lock is exclusive for opencount tests */ vn_lock(ap->a_vp, LK_UPGRADE | LK_RETRY); switch (pfs->pfs_type) { case Pmem: if ((ap->a_fflag & FWRITE) && (pfs->pfs_flags & O_EXCL)) pfs->pfs_flags &= ~(FWRITE|O_EXCL); /* * v_opencount determines the last real close on the vnode. * * If this is the last close, then it checks to see if * the target process has PF_LINGER set in p_pfsflags, * if this is *not* the case, then the process' stop flags * are cleared, and the process is woken up. This is * to help prevent the case where a process has been * told to stop on an event, but then the requesting process * has gone away or forgotten about it. */ p = NULL; if ((ap->a_vp->v_opencount < 2) && ((p = pfs_pfind(pfs->pfs_pid)) != NULL || (p = pfs_zpfind(pfs->pfs_pid)) != NULL) && !(p->p_pfsflags & PF_LINGER)) { spin_lock(&p->p_spin); p->p_stops = 0; p->p_step = 0; spin_unlock(&p->p_spin); wakeup(&p->p_stype); wakeup(&p->p_step); } pfs_pdone(p); break; default: break; } return (vop_stdclose(ap)); } /* * do an ioctl operation on a pfsnode (vp). * (vp) is not locked on entry or exit. */ static int procfs_ioctl(struct vop_ioctl_args *ap) { struct pfsnode *pfs = VTOPFS(ap->a_vp); struct proc *procp; struct proc *p; int error; int signo; struct procfs_status *psp; unsigned char flags; procp = pfs_pfind(pfs->pfs_pid); if (procp == NULL) return ENOTTY; p = curproc; if (p == NULL) { error = EINVAL; goto done; } /* Can't trace a process that's currently exec'ing. */ if ((procp->p_flags & P_INEXEC) != 0) { error = EAGAIN; goto done; } if (!CHECKIO(p, procp) || p_trespass(ap->a_cred, procp->p_ucred)) { error = EPERM; goto done; } switch (ap->a_command) { case PIOCBIS: spin_lock(&procp->p_spin); procp->p_stops |= *(unsigned int*)ap->a_data; spin_unlock(&procp->p_spin); break; case PIOCBIC: spin_lock(&procp->p_spin); procp->p_stops &= ~*(unsigned int*)ap->a_data; spin_unlock(&procp->p_spin); break; case PIOCSFL: /* * NFLAGS is "non-suser_xxx flags" -- currently, only * PFS_ISUGID ("ignore set u/g id"); */ #define NFLAGS (PF_ISUGID) flags = (unsigned char)*(unsigned int*)ap->a_data; if (flags & NFLAGS && (error = caps_priv_check(ap->a_cred, SYSCAP_RESTRICTEDROOT))) { goto done; } procp->p_pfsflags = flags; break; case PIOCGFL: *(unsigned int*)ap->a_data = (unsigned int)procp->p_pfsflags; break; case PIOCSTATUS: /* * NOTE: syscall entry deals with stopevents and may run * without the MP lock. */ psp = (struct procfs_status *)ap->a_data; psp->flags = procp->p_pfsflags; psp->events = procp->p_stops; spin_lock(&procp->p_spin); if (procp->p_step) { psp->state = 0; psp->why = procp->p_stype; psp->val = procp->p_xstat; spin_unlock(&procp->p_spin); } else { psp->state = 1; spin_unlock(&procp->p_spin); psp->why = 0; /* Not defined values */ psp->val = 0; /* Not defined values */ } break; case PIOCWAIT: /* * NOTE: syscall entry deals with stopevents and may run * without the MP lock. */ psp = (struct procfs_status *)ap->a_data; spin_lock(&procp->p_spin); while (procp->p_step == 0) { tsleep_interlock(&procp->p_stype, PCATCH); spin_unlock(&procp->p_spin); if (procp->p_stops == 0) { error = 0; goto done; } if (procp->p_flags & P_POSTEXIT) { error = EINVAL; goto done; } if (procp->p_flags & P_INEXEC) { error = EAGAIN; goto done; } error = tsleep(&procp->p_stype, PCATCH | PINTERLOCKED, "piocwait", 0); if (error) goto done; spin_lock(&procp->p_spin); } spin_unlock(&procp->p_spin); psp->state = 1; /* It stopped */ psp->flags = procp->p_pfsflags; psp->events = procp->p_stops; psp->why = procp->p_stype; /* why it stopped */ psp->val = procp->p_xstat; /* any extra info */ break; case PIOCCONT: /* Restart a proc */ /* * NOTE: syscall entry deals with stopevents and may run * without the MP lock. However, the caller is * presumably interlocked by having waited. */ if (procp->p_step == 0) { error = EINVAL; /* Can only start a stopped process */ goto done; } if ((signo = *(int*)ap->a_data) != 0) { if (signo >= NSIG || signo <= 0) { error = EINVAL; goto done; } ksignal(procp, signo); } procp->p_step = 0; wakeup(&procp->p_step); break; default: error = ENOTTY; goto done; } error = 0; done: pfs_pdone(procp); return error; } /* * 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. * * XXX mmap assumes buffer cache operation * * procfs_bmap(struct vnode *a_vp, off_t a_loffset, * off_t *a_doffsetp, int *a_runp, int *a_runb) */ static int procfs_bmap(struct vop_bmap_args *ap) { if (ap->a_doffsetp != NULL) *ap->a_doffsetp = ap->a_loffset; if (ap->a_runp != NULL) *ap->a_runp = 0; if (ap->a_runb != NULL) *ap->a_runb = 0; return (0); } /* * procfs_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. * * (vp) is locked on entry, but must be unlocked on exit. * * procfs_inactive(struct vnode *a_vp) */ static int procfs_inactive(struct vop_inactive_args *ap) { struct pfsnode *pfs = VTOPFS(ap->a_vp); if (pfs->pfs_pid & PFS_DEAD) vrecycle(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(struct vnode *a_vp) */ static int procfs_reclaim(struct vop_reclaim_args *ap) { return (procfs_freevp(ap->a_vp)); } /* * _print is used for debugging. * just print a readable description * of (vp). * * procfs_print(struct vnode *a_vp) */ static int procfs_print(struct vop_print_args *ap) { struct pfsnode *pfs = VTOPFS(ap->a_vp); kprintf("tag VT_PROCFS, type %d, pid %ld, mode %x, flags %lx\n", pfs->pfs_type, (long)pfs->pfs_pid, pfs->pfs_mode, pfs->pfs_flags); return (0); } /* * generic entry point for unsupported operations */ static int procfs_badop(struct vop_generic_args *ap) { 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(struct vnode *a_vp, struct vattr *a_vap) */ static int procfs_getattr(struct vop_getattr_args *ap) { struct pfsnode *pfs = VTOPFS(ap->a_vp); struct vattr *vap = ap->a_vap; struct proc *procp; int error; /* * First make sure that the process and its credentials * still exist. */ switch (pfs->pfs_type) { case Proot: case Pcurproc: procp = NULL; break; default: procp = pfs_pfind(pfs->pfs_pid); if (procp == NULL || procp->p_ucred == NULL) { error = ENOENT; goto done; } break; } 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; vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0]; /* * 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. */ vfs_timestamp(&vap->va_ctime); vap->va_atime = vap->va_mtime = vap->va_ctime; /* * 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 Pctl: case Pregs: case Pfpregs: case Pdbregs: case Pmem: if (procp->p_flags & P_SUGID) { vap->va_mode &= ~((VREAD|VWRITE)| ((VREAD|VWRITE)>>3)| ((VREAD|VWRITE)>>6)); } break; default: break; } /* * 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. */ vap->va_nlink = 1; if (procp) { if (procp->p_ucred) { vap->va_uid = procp->p_ucred->cr_uid; vap->va_gid = procp->p_ucred->cr_gid; } else { vap->va_uid = -1; vap->va_gid = -1; } } switch (pfs->pfs_type) { case Proot: /* * Set nlink to 1 to tell fts(3) we don't actually know. */ vap->va_nlink = 1; vap->va_uid = 0; vap->va_gid = 0; vap->va_size = vap->va_bytes = DEV_BSIZE; break; case Pcurproc: { char buf[16]; /* should be enough */ vap->va_uid = 0; vap->va_gid = 0; vap->va_size = ksnprintf(buf, sizeof(buf), "%ld", (long)curproc->p_pid); vap->va_bytes = vap->va_size; break; } case Pproc: vap->va_nlink = nproc_targets; vap->va_size = vap->va_bytes = DEV_BSIZE; break; case Pfile: { char *fullpath, *freepath; if (procp->p_textnch.ncp) { struct nchandle nch; cache_copy(&procp->p_textnch, &nch); error = cache_fullpath(procp, &nch, NULL, &fullpath, &freepath, 0); cache_drop(&nch); } else { error = EINVAL; } if (error == 0) { vap->va_size = strlen(fullpath); kfree(freepath, M_TEMP); } else { vap->va_size = sizeof("unknown") - 1; error = 0; } vap->va_bytes = vap->va_size; break; } case Pmem: /* * If we denied owner access earlier, then we have to * change the owner to root - otherwise 'ps' and friends * will break even though they are setgid kmem. *SIGH* */ if (procp->p_flags & P_SUGID) vap->va_uid = 0; else if (procp->p_ucred) vap->va_uid = procp->p_ucred->cr_uid; else vap->va_uid = -1; break; case Pregs: vap->va_bytes = vap->va_size = sizeof(struct reg); break; case Pfpregs: vap->va_bytes = vap->va_size = sizeof(struct fpreg); break; case Pdbregs: vap->va_bytes = vap->va_size = sizeof(struct dbreg); break; case Ptype: case Pmap: case Pctl: case Pstatus: case Pnote: case Pnotepg: case Pcmdline: case Prlimit: break; default: panic("procfs_getattr"); } done: pfs_pdone(procp); return (error); } /* * procfs_setattr(struct vnode *a_vp, struct vattr *a_vap, * struct ucred *a_cred) */ static int procfs_setattr(struct vop_setattr_args *ap) { if (ap->a_vap->va_flags != VNOVAL) return (EOPNOTSUPP); /* * 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. * * procfs_access(struct vnode *a_vp, int a_mode, struct ucred *a_cred) */ static int procfs_access(struct vop_access_args *ap) { struct vattr vattr; int error; error = VOP_GETATTR(ap->a_vp, &vattr); if (!error) error = vop_helper_access(ap, vattr.va_uid, vattr.va_gid, vattr.va_mode, 0); return (error); } /* * lookup. this is incredibly complicated in the general case, however * for most pseudo-filesystems very little needs to be done. * * procfs_lookup(struct vnode *a_dvp, struct vnode **a_vpp, * struct componentname *a_cnp) */ static int procfs_lookup(struct vop_old_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; /* struct proc *curp = cnp->cn_proc; */ struct proc_target *pt; pid_t pid; struct pfsnode *pfs; struct proc *p; struct lwp *lp; int i; int error; *vpp = NULL; if (cnp->cn_nameiop == NAMEI_DELETE || cnp->cn_nameiop == NAMEI_RENAME) return (EROFS); p = NULL; error = 0; if (cnp->cn_namelen == 1 && *pname == '.') { *vpp = dvp; vref(*vpp); goto out; } pfs = VTOPFS(dvp); switch (pfs->pfs_type) { case Proot: if (cnp->cn_flags & CNP_ISDOTDOT) return (EIO); if (CNEQ(cnp, "curproc", 7) || CNEQ(cnp, "self", 4)) { error = procfs_allocvp(dvp->v_mount, vpp, 0, Pcurproc); goto out; } pid = atopid(pname, cnp->cn_namelen); if (pid == NO_PID) break; p = pfs_pfind(pid); if (p == NULL) break; if (!PRISON_CHECK(ap->a_cnp->cn_cred, p->p_ucred)) break; if (ps_showallprocs == 0 && ap->a_cnp->cn_cred->cr_uid != 0 && ap->a_cnp->cn_cred->cr_uid != p->p_ucred->cr_uid) break; error = procfs_allocvp(dvp->v_mount, vpp, pid, Pproc); goto out; case Pproc: if (cnp->cn_flags & CNP_ISDOTDOT) { error = procfs_root(dvp->v_mount, vpp); goto out; } p = pfs_pfind(pfs->pfs_pid); if (p == NULL) break; /* XXX lwp */ lp = FIRST_LWP_IN_PROC(p); if (lp == NULL) break; if (!PRISON_CHECK(ap->a_cnp->cn_cred, p->p_ucred)) break; if (ps_showallprocs == 0 && ap->a_cnp->cn_cred->cr_uid != 0 && ap->a_cnp->cn_cred->cr_uid != p->p_ucred->cr_uid) break; for (pt = proc_targets, i = 0; i < nproc_targets; pt++, i++) { if (cnp->cn_namelen == pt->pt_namlen && bcmp(pt->pt_name, pname, cnp->cn_namelen) == 0 && (pt->pt_valid == NULL || (*pt->pt_valid)(lp))) goto found; } break; found: error = procfs_allocvp(dvp->v_mount, vpp, pfs->pfs_pid, pt->pt_pfstype); goto out; default: error = ENOTDIR; goto out; } if (cnp->cn_nameiop == NAMEI_LOOKUP) error = ENOENT; else error = EROFS; /* * If no error occured *vpp will hold a referenced locked vnode. * dvp was passed to us locked and *vpp must be returned locked. * If *vpp != dvp then we should unlock dvp if (1) this is not the * last component or (2) CNP_LOCKPARENT is not set. */ out: if (error == 0 && *vpp != dvp) { if ((cnp->cn_flags & CNP_LOCKPARENT) == 0) { cnp->cn_flags |= CNP_PDIRUNLOCK; vn_unlock(dvp); } } pfs_pdone(p); return (error); } /* * Does this process have a text file? */ int procfs_validfile(struct lwp *lp) { return (procfs_findtextvp(lp->lwp_proc) != NULLVP); } /* * readdir() returns directory entries from pfsnode (vp). * * We generate just one directory entry at a time, as it would probably * not pay off to buffer several entries locally to save uiomove calls. * * procfs_readdir(struct vnode *a_vp, struct uio *a_uio, struct ucred *a_cred, * int *a_eofflag, int *a_ncookies, off_t **a_cookies) */ static int procfs_readdir(struct vop_readdir_args *ap) { struct pfsnode *pfs; int error; if (ap->a_uio->uio_offset < 0 || ap->a_uio->uio_offset > INT_MAX) return (EINVAL); error = vn_lock(ap->a_vp, LK_EXCLUSIVE | LK_RETRY | LK_FAILRECLAIM); if (error) return (error); pfs = VTOPFS(ap->a_vp); switch (pfs->pfs_type) { case Pproc: /* * 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). */ error = procfs_readdir_proc(ap); break; case Proot: /* * 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 */ error = procfs_readdir_root(ap); break; default: error = ENOTDIR; break; } vn_unlock(ap->a_vp); return (error); } static int procfs_readdir_proc(struct vop_readdir_args *ap) { struct pfsnode *pfs; int error, i, retval; struct proc *p; struct lwp *lp; struct proc_target *pt; struct uio *uio = ap->a_uio; pfs = VTOPFS(ap->a_vp); p = pfs_pfind(pfs->pfs_pid); if (p == NULL) return(0); if (!PRISON_CHECK(ap->a_cred, p->p_ucred)) { error = 0; goto done; } /* XXX lwp, not MPSAFE */ lp = FIRST_LWP_IN_PROC(p); if (lp == NULL) { error = EINVAL; goto done; } error = 0; i = (int)uio->uio_offset; if (i < 0) { error = EINVAL; goto done; } for (pt = &proc_targets[i]; !error && uio->uio_resid > 0 && i < nproc_targets; pt++, i++) { if (pt->pt_valid && (*pt->pt_valid)(lp) == 0) continue; retval = vop_write_dirent(&error, uio, PROCFS_FILENO(pfs->pfs_pid, pt->pt_pfstype), pt->pt_type, pt->pt_namlen, pt->pt_name); if (retval) break; } uio->uio_offset = (off_t)i; error = 0; done: pfs_pdone(p); return error; } struct procfs_readdir_root_info { int error; int i; int pcnt; struct uio *uio; struct ucred *cred; }; static int procfs_readdir_root_callback(struct proc *p, void *data); static int procfs_readdir_root(struct vop_readdir_args *ap) { struct procfs_readdir_root_info info; struct uio *uio = ap->a_uio; int res; res = 0; info.error = 0; info.i = (int)uio->uio_offset; if (info.i < 0) return (EINVAL); info.pcnt = 0; info.uio = uio; info.cred = ap->a_cred; while (info.pcnt < 4) { res = procfs_readdir_root_callback(NULL, &info); if (res < 0) break; } if (res >= 0) allproc_scan(procfs_readdir_root_callback, &info, 0); uio->uio_offset = (off_t)info.i; return (info.error); } static int procfs_readdir_root_callback(struct proc *p, void *data) { struct procfs_readdir_root_info *info = data; struct uio *uio; int retval; ino_t d_ino; const char *d_name; char d_name_pid[20]; size_t d_namlen; uint8_t d_type; uio = info->uio; if (uio->uio_resid <= 0 || info->error) return(-1); switch (info->pcnt) { case 0: /* `.' */ d_ino = PROCFS_FILENO(0, Proot); d_name = "."; d_namlen = 1; d_type = DT_DIR; break; case 1: /* `..' */ d_ino = PROCFS_FILENO(0, Proot); d_name = ".."; d_namlen = 2; d_type = DT_DIR; break; case 2: d_ino = PROCFS_FILENO(0, Pcurproc); d_namlen = 7; d_name = "curproc"; d_type = DT_LNK; break; case 3: d_ino = PROCFS_FILENO(0, Pcurproc); d_namlen = 4; d_name = "self"; d_type = DT_LNK; break; default: if (!PRISON_CHECK(info->cred, p->p_ucred)) return(0); if (ps_showallprocs == 0 && info->cred->cr_uid != 0 && info->cred->cr_uid != p->p_ucred->cr_uid) { return(0); } /* * Skip entries we have already returned (optimization) */ if (info->pcnt < info->i) { ++info->pcnt; return(0); } d_ino = PROCFS_FILENO(p->p_pid, Pproc); d_namlen = ksnprintf(d_name_pid, sizeof(d_name_pid), "%ld", (long)p->p_pid); d_name = d_name_pid; d_type = DT_DIR; break; } /* * Skip entries we have already returned (optimization) */ if (info->pcnt < info->i) { ++info->pcnt; return(0); } retval = vop_write_dirent(&info->error, uio, d_ino, d_type, d_namlen, d_name); if (retval) return(-1); ++info->pcnt; ++info->i; return(0); } /* * readlink reads the link of `curproc' or `file' */ static int procfs_readlink(struct vop_readlink_args *ap) { char buf[16]; /* should be enough */ struct proc *procp; struct vnode *vp = ap->a_vp; struct pfsnode *pfs = VTOPFS(vp); char *fullpath, *freepath; int error, len; switch (pfs->pfs_type) { case Pcurproc: if (pfs->pfs_fileno != PROCFS_FILENO(0, Pcurproc)) return (EINVAL); len = ksnprintf(buf, sizeof(buf), "%ld", (long)curproc->p_pid); return (uiomove(buf, len, ap->a_uio)); case Pfile: /* * procfs's directory topology is somewhat asynchronous from * reality so it is possible for pid requests to race exiting * processes. In this situation, bit 31 is set in * pfs->pfs_pid which guarantees that pfs_pfind() will return * NULL. * * It is also possible to catch a process in the middle of * an exit sequence so various fields might wind up being * NULL that are not normally NULL. */ procp = pfs_pfind(pfs->pfs_pid); if (procp == NULL || procp->p_ucred == NULL) { pfs_pdone(procp); return (uiomove("unknown", sizeof("unknown") - 1, ap->a_uio)); } if (procp->p_textnch.ncp) { struct nchandle nch; cache_copy(&procp->p_textnch, &nch); error = cache_fullpath(procp, &nch, NULL, &fullpath, &freepath, 0); cache_drop(&nch); } else { error = EINVAL; } if (error != 0) { pfs_pdone(procp); return (uiomove("unknown", sizeof("unknown") - 1, ap->a_uio)); } error = uiomove(fullpath, strlen(fullpath), ap->a_uio); kfree(freepath, M_TEMP); pfs_pdone(procp); return (error); default: return (EINVAL); } } /* * convert decimal ascii to pid_t */ static pid_t atopid(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); } /* * kqfilter operations */ static void procfs_filt_detach(struct knote *kn) { struct vnode *vp = (void *)kn->kn_hook; knote_remove(&vp->v_pollinfo.vpi_kqinfo.ki_note, kn); } static int procfs_filt_read(struct knote *kn, long hint) { if (hint == NOTE_REVOKE) { kn->kn_flags |= (EV_EOF | EV_NODATA | EV_ONESHOT); return (1); } /* Files on procfs have a size of 0. */ kn->kn_data = 0; if (kn->kn_sfflags & NOTE_OLDAPI) return (1); return (kn->kn_data != 0); } static int procfs_filt_write(struct knote *kn, long hint) { if (hint == NOTE_REVOKE) kn->kn_flags |= (EV_EOF | EV_NODATA | EV_ONESHOT); kn->kn_data = 0; return (1); } static int procfs_filt_vnode(struct knote *kn, long hint) { if (kn->kn_sfflags & hint) kn->kn_fflags |= hint; if (hint == NOTE_REVOKE) { kn->kn_flags |= (EV_EOF | EV_NODATA); return (1); } return (kn->kn_fflags != 0); } static struct filterops procfs_read_filtops = { FILTEROP_ISFD | FILTEROP_MPSAFE, NULL, procfs_filt_detach, procfs_filt_read, }; static struct filterops procfs_write_filtops = { FILTEROP_ISFD | FILTEROP_MPSAFE, NULL, procfs_filt_detach, procfs_filt_write, }; static struct filterops procfs_vnode_filtops = { FILTEROP_ISFD | FILTEROP_MPSAFE, NULL, procfs_filt_detach, procfs_filt_vnode, }; static int procfs_kqfilter(struct vop_kqfilter_args *ap) { struct vnode *vp = ap->a_vp; struct knote *kn = ap->a_kn; switch (kn->kn_filter) { case EVFILT_READ: kn->kn_fop = &procfs_read_filtops; break; case EVFILT_WRITE: kn->kn_fop = &procfs_write_filtops; break; case EVFILT_VNODE: kn->kn_fop = &procfs_vnode_filtops; break; default: return (EOPNOTSUPP); } kn->kn_hook = (caddr_t)vp; knote_insert(&vp->v_pollinfo.vpi_kqinfo.ki_note, kn); return (0); }