add missing bump to reference count

[unix-history] / usr / src / sys / kern / kern_ktrace.c

/*
* Copyright (c) 1989 The Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that the above copyright notice and this paragraph are
* duplicated in all such forms and that any documentation,
* advertising materials, and other materials related to such
* distribution and use acknowledge that the software was developed
* by the University of California, Berkeley.  The name of the
* University may not be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*
*      @(#)kern_ktrace.c       1.5 (Berkeley) %G%
*/

#ifdef KTRACE

#include "param.h"
#include "user.h"
#include "proc.h"
#include "file.h"
#include "vnode.h"
#include "ktrace.h"
#include "malloc.h"

#include "syscalls.c"

extern int nsysent;
extern char *syscallnames[];

int ktrace_nocheck = 1;

struct ktr_header *
ktrgetheader(type)
{
       register struct ktr_header *kth;

       MALLOC(kth, struct ktr_header *, sizeof (struct ktr_header), 
               M_TEMP, M_WAITOK);
       kth->ktr_type = type;
       microtime(&kth->ktr_time);
       kth->ktr_pid = u.u_procp->p_pid;
       bcopy(u.u_comm, kth->ktr_comm, MAXCOMLEN);
       return (kth);
}

ktrsyscall(vp, code, narg)
       struct vnode *vp;
{
       struct  ktr_header *kth = ktrgetheader(KTR_SYSCALL);
       struct  ktr_syscall *ktp;
       register len = sizeof(struct ktr_syscall) + (narg * sizeof(int));
       int     *argp, i;

       if (kth == NULL)
               return;
       MALLOC(ktp, struct ktr_syscall *, len, M_TEMP, M_WAITOK);
       ktp->ktr_code = code;
       ktp->ktr_narg = narg;
       argp = (int *)((char *)ktp + sizeof(struct ktr_syscall));
       for (i = 0; i < narg; i++)
               *argp++ = u.u_arg[i];
       kth->ktr_buf = (caddr_t)ktp;
       kth->ktr_len = len;
       ktrwrite(vp, kth);
       FREE(ktp, M_TEMP);
       FREE(kth, M_TEMP);
}

ktrsysret(vp, code)
       struct vnode *vp;
{
       struct ktr_header *kth = ktrgetheader(KTR_SYSRET);
       struct ktr_sysret *ktp;

       if (kth == NULL)
               return;
       MALLOC(ktp, struct ktr_sysret *, sizeof(struct ktr_sysret),
               M_TEMP , M_WAITOK);
       ktp->ktr_code = code;
       ktp->ktr_eosys = u.u_eosys;
       ktp->ktr_error = u.u_error;
       ktp->ktr_retval = u.u_r.r_val1;         /* what about val2 ? */

       kth->ktr_buf = (caddr_t)ktp;
       kth->ktr_len = sizeof(struct ktr_sysret);

       ktrwrite(vp, kth);
       FREE(ktp, M_TEMP);
       FREE(kth, M_TEMP);
}

ktrnamei(vp, path)
       struct vnode *vp;
       char *path;
{
       struct ktr_header *kth = ktrgetheader(KTR_NAMEI);

       if (kth == NULL)
               return;
       kth->ktr_len = strlen(path);
       kth->ktr_buf = path;

       ktrwrite(vp, kth);
       FREE(kth, M_TEMP);
}

ktrgenio(vp, fd, rw, iov, len)
       struct vnode *vp;
       enum uio_rw rw;
       register struct iovec *iov;
{
       struct ktr_header *kth = ktrgetheader(KTR_GENIO);
       register struct ktr_genio *ktp;
       register caddr_t cp;
       register int resid = len, cnt;
       
       if (kth == NULL || u.u_error)
               return;
       MALLOC(ktp, struct ktr_genio *, sizeof(struct ktr_genio) + len,
               M_TEMP, M_WAITOK);
       ktp->ktr_fd = fd;
       ktp->ktr_rw = rw;
       cp = (caddr_t)((char *)ktp + sizeof (struct ktr_genio));
       while (resid > 0) {
               if ((cnt = iov->iov_len) > resid)
                       cnt = resid;
               if (copyin(iov->iov_base, cp, cnt))
                       goto done;
               cp += cnt;
               resid -= cnt;
               iov++;
       }
       kth->ktr_buf = (caddr_t)ktp;
       kth->ktr_len = sizeof (struct ktr_genio) + len;

       ktrwrite(vp, kth);
done:
       FREE(kth, M_TEMP);
       FREE(ktp, M_TEMP);
}

/*
* ktrace system call
*/
ktrace()
{
       register struct a {
               char    *fname;
               int     ops;
               int     facs;
               int     pid;
       } *uap = (struct a *)u.u_ap;
       register struct vnode *vp = NULL;
       register struct nameidata *ndp = &u.u_nd;
       register struct proc *p;
       struct pgrp *pg;
       register int ops = uap->ops&0x3;
       register int facs = uap->facs;
       register int ret = 0;

       /*
        * Until security implications are thought through,
        * limit tracing to root (unless ktrace_nocheck is set).
        */
       if (!ktrace_nocheck && (u.u_error = suser(u.u_cred, &u.u_acflag)))
               return;
       if (ops != KTROP_CLEAR) {
               /*
                * an operation which requires a file argument.
                */
               ndp->ni_segflg = UIO_USERSPACE;
               ndp->ni_dirp = uap->fname;
               if (u.u_error = vn_open(ndp, FREAD|FWRITE, 0))
                       return;
               vp = ndp->ni_vp;
               if (vp->v_type != VREG) {
                       u.u_error = EACCES;
                       vrele(vp);
                       return;
               }
       }
       /*
        * Clear all uses of the tracefile
        */
       if (ops == KTROP_CLEARFILE) {
               for (p = allproc; p != NULL; p = p->p_nxt) {
                       if (p->p_tracep == vp) {
                               p->p_flag &= ~SKTR;
                               p->p_tracep = NULL;
                               p->p_traceflag = 0;
                               vrele(vp);
                       }
               }
               goto done;
       }

       /*
        * need something to (un)trace
        */
       if (!facs) {
               u.u_error = EINVAL;
               goto done;
       }

       if (uap->pid < 0) {
               pg = pgfind(-uap->pid);
               if (pg == NULL) {
                       u.u_error = ESRCH;
                       goto done;
               }
               for (p = pg->pg_mem; p != NULL; p = p->p_pgrpnxt)
                       if (uap->ops&KTROP_INHERITFLAG)
                               ret |= ktrsetchildren(p, ops, facs, vp);
                       else 
                               ret |= ktrops(p, ops, facs, vp);
                                       
       } else {
               p = pfind(uap->pid);
               if (p == NULL) {
                       u.u_error = ESRCH;
                       goto done;
               }
               if (uap->ops&KTROP_INHERITFLAG)
                       ret |= ktrsetchildren(p, ops, facs, vp);
               else
                       ret |= ktrops(p, ops, facs, vp);
       }
       if (!ret)
               u.u_error = EPERM;
done:
       if (vp != NULL)
               vrele(vp);
}

ktrops(p, ops, facs, vp)
       struct proc *p;
       struct vnode *vp;
{

       if (u.u_uid && u.u_uid != p->p_uid)
               return 0;
       if (ops == KTROP_SET) {
               if (p->p_tracep != vp) {
                       /*
                        * if trace file already in use, relinquish
                        */
                       if (p->p_tracep != NULL)
                               vrele(p->p_tracep);
                       VREF(vp);
                       p->p_tracep = vp;
               }
               p->p_traceflag |= facs;
       } else {        
               /* KTROP_CLEAR */
               if ((p->p_traceflag &= ~facs) == 0) {
                       if (p->p_tracep != NULL) {
                               vrele(p->p_tracep);
                               p->p_tracep = NULL;
                       }
                       p->p_flag &= ~SKTR;
               }
       }

       return 1;
}

ktrsetchildren(top, ops, facs, vp)
       struct proc *top;
       struct vnode *vp;
{
       register struct proc *p;
       register int ndx;
       register int ret = 0;

       p = top;
       for (;;) {
               if ((ret |= ktrops(p, ops, facs, vp)) && ops == KTROP_SET)
                       p->p_flag |= SKTR;
               /*
                * If this process has children, descend to them next,
                * otherwise do any siblings, and if done with this level,
                * follow back up the tree (but not past top).
                */
               if (p->p_cptr)
                       p = p->p_cptr;
               else if (p == top)
                       return ret;
               else if (p->p_osptr)
                       p = p->p_osptr;
               else for (;;) {
                       p = p->p_pptr;
                       if (p == top)
                               return ret;
                       if (p->p_osptr) {
                               p = p->p_osptr;
                               break;
                       }
               }
       }
       /*NOTREACHED*/
}

ktrwrite(vp, kth)
       struct vnode *vp;
       register struct ktr_header *kth;
{
       struct uio auio;
       struct iovec aiov[2];
       int offset, error;

       if (vp == NULL)
               return;
       auio.uio_iov = &aiov[0];
       auio.uio_offset = 0;
       auio.uio_segflg = UIO_SYSSPACE;
       auio.uio_rw = UIO_WRITE;
       aiov[0].iov_base = (caddr_t)kth;
       aiov[0].iov_len = sizeof(struct ktr_header);
       auio.uio_resid = sizeof(struct ktr_header);
       auio.uio_iovcnt = 1;
       if (kth->ktr_len > 0) {
               auio.uio_iovcnt++;
               aiov[1].iov_base = kth->ktr_buf;
               aiov[1].iov_len = kth->ktr_len;
               auio.uio_resid += kth->ktr_len;
       }
       error = VOP_WRITE(vp, &auio, &offset, IO_UNIT|IO_APPEND, u.u_cred);
}
#endif