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minix/kernel/system/do_privctl.c
Ben Gras 41e9fedf87 Mostly bugfixes of bugs triggered by the test set. 
bugfixes:
 SYSTEM:
 . removed
        rc->p_priv->s_flags = 0;
   for the priv struct shared by all user processes in get_priv(). this
   should only be done once. doing a SYS_PRIV_USER in sys_privctl()
   caused the flags of all user processes to be reset, so they were no
   longer PREEMPTIBLE. this happened when RS executed a policy script.
   (this broke test1 in the test set)

 VFS/MFS:
 . chown can change the mode of a file, and chmod arguments are only
   part of the full file mode so the full filemode is slightly magic.
   changed these calls so that the final modes are returned to VFS, so
   that the vnode can be kept up-to-date.
   (this broke test11 in the test set)

 MFS:
 . lookup() checked for sizeof(string) instead of sizeof(user_path),
   truncating long path names
   (caught by test 23)
 . truncate functions neglected to update ctime
   (this broke test16)

 VFS:
 . corner case of an empty filename lookup caused fields of a request
   not to be filled in in the lookup functions, not making it clear
   that the lookup had failed, causing messages to garbage processes,
   causing strange failures.
   (caught by test 30)
 . trust v_size in vnode when doing reads or writes on non-special
   files, truncating i/o where necessary; this is necessary for pipes,
   as MFS can't tell when a pipe has been truncated without it being
   told explicitly each time.
   when the last reader/writer on a pipe closes, tell FS about
   the new size using truncate_vn().
   (this broke test 25, among others)
 . permission check for chdir() had disappeared; added a
   forbidden() call
   (caught by test 23)

new code, shouldn't change anything:
 . introduced RTS_SET, RTS_UNSET, and RTS_ISSET macro's, and their
   LOCK variants. These macros set and clear the p_rts_flags field,
   causing a lot of duplicated logic like

       old_flags = rp->p_rts_flags;            /* save value of the flags */
       rp->p_rts_flags &= ~NO_PRIV;
       if (old_flags != 0 && rp->p_rts_flags == 0) lock_enqueue(rp);

   to change into the simpler

       RTS_LOCK_UNSET(rp, NO_PRIV);

   so the macros take care of calling dequeue() and enqueue() (or lock_*()),
   as the case may be). This makes the code a bit more readable and a
   bit less fragile.
 . removed return code from do_clocktick in CLOCK as it currently
   never replies
 . removed some debug code from VFS
 . fixed grant debug message in device.c
 
preemptive checks, tests, changes:
 . added return code checks of receive() to SYSTEM and CLOCK
 . O_TRUNC should never arrive at MFS (added sanity check and removed
   O_TRUNC code)
 . user_path declared with PATH_MAX+1 to let it be null-terminated
 . checks in MFS to see if strings passed by VFS are null-terminated
 
 IS:
 . static irq name table thrown out
2007-02-01 17:50:02 +00:00

225 lines
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/* The kernel call implemented in this file:
* m_type: SYS_PRIVCTL
*
* The parameters for this kernel call are:
* m1_i1: PR_ENDPT (process number of caller)
*/
#include "../system.h"
#include "../ipc.h"
#include <signal.h>
#include <string.h>
#if USE_PRIVCTL
#define FILLED_MASK (~0)
/*===========================================================================*
* do_privctl *
*===========================================================================*/
PUBLIC int do_privctl(m_ptr)
message *m_ptr; /* pointer to request message */
{
/* Handle sys_privctl(). Update a process' privileges. If the process is not
* yet a system process, make sure it gets its own privilege structure.
*/
register struct proc *caller_ptr;
register struct proc *rp;
register struct priv *sp;
int proc_nr;
int priv_id;
int i;
phys_bytes caller_phys, kernel_phys;
struct io_range io_range;
struct mem_range mem_range;
struct priv priv;
/* Check whether caller is allowed to make this call. Privileged proceses
* can only update the privileges of processes that are inhibited from
* running by the NO_PRIV flag. This flag is set when a privileged process
* forks.
*/
caller_ptr = proc_addr(who_p);
if (! (priv(caller_ptr)->s_flags & SYS_PROC)) return(EPERM);
if(m_ptr->PR_ENDPT == SELF) proc_nr = who_p;
else if(!isokendpt(m_ptr->PR_ENDPT, &proc_nr)) return(EINVAL);
rp = proc_addr(proc_nr);
switch(m_ptr->CTL_REQUEST)
{
case SYS_PRIV_INIT:
if (! RTS_ISSET(rp, NO_PRIV)) return(EPERM);
/* Make sure this process has its own privileges structure. This may
* fail, since there are only a limited number of system processes.
* Then copy the privileges from the caller and restore some defaults.
*/
if ((i=get_priv(rp, SYS_PROC)) != OK) return(i);
priv_id = priv(rp)->s_id; /* backup privilege id */
*priv(rp) = *priv(caller_ptr); /* copy from caller */
priv(rp)->s_id = priv_id; /* restore privilege id */
priv(rp)->s_proc_nr = proc_nr; /* reassociate process nr */
for (i=0; i< BITMAP_CHUNKS(NR_SYS_PROCS); i++) /* remove pending: */
priv(rp)->s_notify_pending.chunk[i] = 0; /* - notifications */
priv(rp)->s_int_pending = 0; /* - interrupts */
sigemptyset(&priv(rp)->s_sig_pending); /* - signals */
/* Now update the process' privileges as requested. */
rp->p_priv->s_trap_mask = FILLED_MASK;
for (i=0; i<BITMAP_CHUNKS(NR_SYS_PROCS); i++) {
rp->p_priv->s_ipc_to.chunk[i] = FILLED_MASK;
}
unset_sys_bit(rp->p_priv->s_ipc_to, USER_PRIV_ID);
/* All process that this process can send to must be able to reply.
* Therefore, their send masks should be updated as well.
*/
for (i=0; i<NR_SYS_PROCS; i++) {
if (get_sys_bit(rp->p_priv->s_ipc_to, i)) {
set_sys_bit(priv_addr(i)->s_ipc_to, priv_id(rp));
}
}
/* No I/O resources, no memory resources, no IRQs, no grant table */
priv(rp)->s_nr_io_range= 0;
priv(rp)->s_nr_mem_range= 0;
priv(rp)->s_nr_irq= 0;
priv(rp)->s_grant_table= 0;
priv(rp)->s_grant_entries= 0;
if (m_ptr->CTL_ARG_PTR)
{
/* Copy privilege structure from caller */
caller_phys = umap_local(caller_ptr, D,
(vir_bytes) m_ptr->CTL_ARG_PTR, sizeof(priv));
if (caller_phys == 0)
return EFAULT;
kernel_phys = vir2phys(&priv);
phys_copy(caller_phys, kernel_phys, sizeof(priv));
/* Copy the call mask */
for (i= 0; i<CALL_MASK_SIZE; i++)
priv(rp)->s_k_call_mask[i]= priv.s_k_call_mask[i];
/* Copy IRQs */
if (priv.s_nr_irq < 0 || priv.s_nr_irq > NR_IRQ)
return EINVAL;
priv(rp)->s_nr_irq= priv.s_nr_irq;
for (i= 0; i<priv.s_nr_irq; i++)
{
priv(rp)->s_irq_tab[i]= priv.s_irq_tab[i];
kprintf("do_privctl: adding IRQ %d\n",
priv(rp)->s_irq_tab[i]);
}
priv(rp)->s_flags |= CHECK_IRQ; /* Check requests for IRQs */
/* Copy I/O ranges */
if (priv.s_nr_io_range < 0 || priv.s_nr_io_range > NR_IO_RANGE)
return EINVAL;
priv(rp)->s_nr_io_range= priv.s_nr_io_range;
for (i= 0; i<priv.s_nr_io_range; i++)
{
priv(rp)->s_io_tab[i]= priv.s_io_tab[i];
kprintf("do_privctl: adding I/O range [%x..%x]\n",
priv(rp)->s_io_tab[i].ior_base,
priv(rp)->s_io_tab[i].ior_limit);
}
/* Check requests for IRQs */
priv(rp)->s_flags |= CHECK_IO_PORT;
memcpy(priv(rp)->s_k_call_mask, priv.s_k_call_mask,
sizeof(priv(rp)->s_k_call_mask));
}
/* Done. Privileges have been set. Allow process to run again. */
RTS_LOCK_UNSET(rp, NO_PRIV);
return(OK);
case SYS_PRIV_USER:
/* Make this process an ordinary user process. */
if (!RTS_ISSET(rp, NO_PRIV)) return(EPERM);
if ((i=get_priv(rp, 0)) != OK) return(i);
RTS_LOCK_UNSET(rp, NO_PRIV);
return(OK);
case SYS_PRIV_ADD_IO:
if (RTS_ISSET(rp, NO_PRIV))
return(EPERM);
/* Only system processes get I/O resources? */
if (!(priv(rp)->s_flags & SYS_PROC))
return EPERM;
/* Get the I/O range */
caller_phys = umap_local(caller_ptr, D, (vir_bytes) m_ptr->CTL_ARG_PTR,
sizeof(io_range));
if (caller_phys == 0)
return EFAULT;
kernel_phys = vir2phys(&io_range);
phys_copy(caller_phys, kernel_phys, sizeof(io_range));
priv(rp)->s_flags |= CHECK_IO_PORT; /* Check I/O accesses */
i= priv(rp)->s_nr_io_range;
if (i >= NR_IO_RANGE)
return ENOMEM;
priv(rp)->s_io_tab[i].ior_base= io_range.ior_base;
priv(rp)->s_io_tab[i].ior_limit= io_range.ior_limit;
priv(rp)->s_nr_io_range++;
return OK;
case SYS_PRIV_ADD_MEM:
if (RTS_ISSET(rp, NO_PRIV))
return(EPERM);
/* Only system processes get memory resources? */
if (!(priv(rp)->s_flags & SYS_PROC))
return EPERM;
/* Get the memory range */
caller_phys = umap_local(caller_ptr, D, (vir_bytes) m_ptr->CTL_ARG_PTR,
sizeof(mem_range));
if (caller_phys == 0)
return EFAULT;
kernel_phys = vir2phys(&mem_range);
phys_copy(caller_phys, kernel_phys, sizeof(mem_range));
priv(rp)->s_flags |= CHECK_MEM; /* Check I/O accesses */
i= priv(rp)->s_nr_mem_range;
if (i >= NR_MEM_RANGE)
return ENOMEM;
#if 0
priv(rp)->s_mem_tab[i].mr_base= mem_range.mr_base;
priv(rp)->s_mem_tab[i].mr_limit= mem_range.mr_limit;
priv(rp)->s_nr_mem_range++;
#endif
return OK;
case SYS_PRIV_ADD_IRQ:
if (RTS_ISSET(rp, NO_PRIV))
return(EPERM);
/* Only system processes get IRQs? */
if (!(priv(rp)->s_flags & SYS_PROC))
return EPERM;
priv(rp)->s_flags |= CHECK_IRQ; /* Check IRQs */
i= priv(rp)->s_nr_irq;
if (i >= NR_IRQ)
return ENOMEM;
priv(rp)->s_irq_tab[i]= m_ptr->CTL_MM_PRIV;
priv(rp)->s_nr_irq++;
return OK;
default:
kprintf("do_privctl: bad request %d\n", m_ptr->CTL_REQUEST);
return EINVAL;
}
}
#endif /* USE_PRIVCTL */
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