| [4] | 1 | /* The kernel call implemented in this file:
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| 2 | * m_type: SYS_PRIVCTL
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| 3 | *
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| 4 | * The parameters for this kernel call are:
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| 5 | * m1_i1: PR_PROC_NR (process number of caller)
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| 6 | */
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| 7 |
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| 8 | #include "../system.h"
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| 9 | #include "../ipc.h"
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| 10 | #include <signal.h>
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| 11 |
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| 12 | #if USE_PRIVCTL
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| 13 |
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| 14 | #define FILLED_MASK (~0)
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| 15 |
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| 16 | /*===========================================================================*
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| 17 | * do_privctl *
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| 18 | *===========================================================================*/
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| 19 | PUBLIC int do_privctl(m_ptr)
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| 20 | message *m_ptr; /* pointer to request message */
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| 21 | {
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| 22 | /* Handle sys_privctl(). Update a process' privileges. If the process is not
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| 23 | * yet a system process, make sure it gets its own privilege structure.
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| 24 | */
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| 25 | register struct proc *caller_ptr;
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| 26 | register struct proc *rp;
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| 27 | register struct priv *sp;
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| 28 | int proc_nr;
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| 29 | int priv_id;
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| 30 | int old_flags;
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| 31 | int i;
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| 32 |
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| 33 | /* Check whether caller is allowed to make this call. Privileged proceses
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| 34 | * can only update the privileges of processes that are inhibited from
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| 35 | * running by the NO_PRIV flag. This flag is set when a privileged process
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| 36 | * forks.
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| 37 | */
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| 38 | caller_ptr = proc_addr(m_ptr->m_source);
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| 39 | if (! (priv(caller_ptr)->s_flags & SYS_PROC)) return(EPERM);
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| 40 | proc_nr = m_ptr->PR_PROC_NR;
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| 41 | if (! isokprocn(proc_nr)) return(EINVAL);
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| 42 | rp = proc_addr(proc_nr);
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| 43 | if (! (rp->p_rts_flags & NO_PRIV)) return(EPERM);
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| 44 |
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| 45 | /* Make sure this process has its own privileges structure. This may fail,
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| 46 | * since there are only a limited number of system processes. Then copy the
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| 47 | * privileges from the caller and restore some defaults.
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| 48 | */
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| 49 | if ((i=get_priv(rp, SYS_PROC)) != OK) return(i);
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| 50 | priv_id = priv(rp)->s_id; /* backup privilege id */
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| 51 | *priv(rp) = *priv(caller_ptr); /* copy from caller */
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| 52 | priv(rp)->s_id = priv_id; /* restore privilege id */
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| 53 | priv(rp)->s_proc_nr = proc_nr; /* reassociate process nr */
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| 54 |
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| 55 | for (i=0; i< BITMAP_CHUNKS(NR_SYS_PROCS); i++) /* remove pending: */
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| 56 | priv(rp)->s_notify_pending.chunk[i] = 0; /* - notifications */
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| 57 | priv(rp)->s_int_pending = 0; /* - interrupts */
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| 58 | sigemptyset(&priv(rp)->s_sig_pending); /* - signals */
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| 59 |
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| 60 | /* Now update the process' privileges as requested. */
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| 61 | rp->p_priv->s_trap_mask = FILLED_MASK;
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| 62 | for (i=0; i<BITMAP_CHUNKS(NR_SYS_PROCS); i++) {
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| 63 | rp->p_priv->s_ipc_to.chunk[i] = FILLED_MASK;
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| 64 | }
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| 65 | unset_sys_bit(rp->p_priv->s_ipc_to, USER_PRIV_ID);
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| 66 |
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| 67 | /* All process that this process can send to must be able to reply.
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| 68 | * Therefore, their send masks should be updated as well.
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| 69 | */
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| 70 | for (i=0; i<NR_SYS_PROCS; i++) {
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| 71 | if (get_sys_bit(rp->p_priv->s_ipc_to, i)) {
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| 72 | set_sys_bit(priv_addr(i)->s_ipc_to, priv_id(rp));
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| 73 | }
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| 74 | }
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| 75 |
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| 76 | /* Done. Privileges have been set. Allow process to run again. */
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| 77 | old_flags = rp->p_rts_flags; /* save value of the flags */
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| 78 | rp->p_rts_flags &= ~NO_PRIV;
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| 79 | if (old_flags != 0 && rp->p_rts_flags == 0) lock_enqueue(rp);
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| 80 | return(OK);
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| 81 | }
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| 82 |
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| 83 | #endif /* USE_PRIVCTL */
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| 84 |
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