minix/kernel/system/do_privctl.c
Cristiano Giuffrida d1fd04e72a Initialization protocol for system services.
SYSLIB CHANGES:
- SEF framework now supports a new SEF Init request type from RS. 3 different
callbacks are available (init_fresh, init_lu, init_restart) to specify
initialization code when a service starts fresh, starts after a live update,
or restarts.

SYSTEM SERVICE CHANGES:
- Initialization code for system services is now enclosed in a callback SEF will
automatically call at init time. The return code of the callback will
tell RS whether the initialization completed successfully.
- Each init callback can access information passed by RS to initialize. As of
now, each system service has access to the public entries of RS's system process
table to gather all the information required to initialize. This design
eliminates many existing or potential races at boot time and provides a uniform
initialization interface to system services. The same interface will be reused
for the upcoming publish/subscribe model to handle dynamic 
registration / deregistration of system services.

VM CHANGES:
- Uniform privilege management for all system services. Every service uses the
same call mask format. For boot services, VM copies the call mask from init
data. For dynamic services, VM still receives the call mask via rs_set_priv
call that will be soon replaced by the upcoming publish/subscribe model.

RS CHANGES:
- The system process table has been reorganized and split into private entries
and public entries. Only the latter ones are exposed to system services.
- VM call masks are now entirely configured in rs/table.c
- RS has now its own slot in the system process table. Only kernel tasks and
user processes not included in the boot image are now left out from the system
process table.
- RS implements the initialization protocol for system services.
- For services in the boot image, RS blocks till initialization is complete and
panics when failure is reported back. Services are initialized in their order of
appearance in the boot image priv table and RS blocks to implements synchronous
initialization for every system service having the flag SF_SYNCH_BOOT set.
- For services started dynamically, the initialization protocol is implemented
as though it were the first ping for the service. In this case, if the
system service fails to report back (or reports failure), RS brings the service
down rather than trying to restart it.
2010-01-08 01:20:42 +00:00

312 lines
8.5 KiB
C

/* The kernel call implemented in this file:
* m_type: SYS_PRIVCTL
*
* The parameters for this kernel call are:
* m2_i1: CTL_ENDPT (process endpoint of target)
* m2_i2: CTL_REQUEST (privilege control request)
* m2_p1: CTL_ARG_PTR (pointer to request data)
*/
#include "../system.h"
#include "../ipc.h"
#include <signal.h>
#include <string.h>
#if USE_PRIVCTL
/*===========================================================================*
* 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;
int proc_nr;
int priv_id;
int ipc_to_m, kcalls;
int i, r;
struct io_range io_range;
struct mem_range mem_range;
struct priv priv;
int irq;
/* 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 RTS_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->CTL_ENDPT == SELF) proc_nr = who_p;
else if(!isokendpt(m_ptr->CTL_ENDPT, &proc_nr)) return(EINVAL);
rp = proc_addr(proc_nr);
switch(m_ptr->CTL_REQUEST)
{
case SYS_PRIV_ALLOW:
/* Allow process to run. Make sure its privilege structure has already
* been set.
*/
if (!RTS_ISSET(rp, RTS_NO_PRIV) || priv(rp)->s_proc_nr == NONE) {
return(EPERM);
}
RTS_LOCK_UNSET(rp, RTS_NO_PRIV);
return(OK);
case SYS_PRIV_DISALLOW:
/* Disallow process from running. */
if (RTS_ISSET(rp, RTS_NO_PRIV)) return(EPERM);
RTS_LOCK_SET(rp, RTS_NO_PRIV);
return(OK);
case SYS_PRIV_SET_SYS:
/* Set a privilege structure of a blocked system process. */
if (! RTS_ISSET(rp, RTS_NO_PRIV)) return(EPERM);
/* Check whether a static or dynamic privilege id must be allocated. */
priv_id = NULL_PRIV_ID;
if (m_ptr->CTL_ARG_PTR)
{
/* Copy privilege structure from caller */
if((r=data_copy(who_e, (vir_bytes) m_ptr->CTL_ARG_PTR,
SYSTEM, (vir_bytes) &priv, sizeof(priv))) != OK)
return r;
/* See if the caller wants to assign a static privilege id. */
if(!(priv.s_flags & DYN_PRIV_ID)) {
priv_id = priv.s_id;
}
}
/* Make sure this process has its own privileges structure. This may
* fail, since there are only a limited number of system processes.
* Then copy privileges from the caller and restore some defaults.
*/
if ((i=get_priv(rp, priv_id)) != OK)
{
kprintf("do_privctl: unable to allocate priv_id %d: %d\n",
priv_id, i);
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< NR_SYS_CHUNKS; 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 */
/* Set defaults for privilege bitmaps. */
priv(rp)->s_flags= DEF_SYS_F; /* privilege flags */
priv(rp)->s_trap_mask= DEF_SYS_T; /* allowed traps */
ipc_to_m = DEF_SYS_M; /* allowed targets */
kcalls = DEF_SYS_KC; /* allowed kernel calls */
for(i = 0; i < SYS_CALL_MASK_SIZE; i++) {
priv(rp)->s_k_call_mask[i] = (kcalls == NO_C ? 0 : (~0));
}
/* Set defaults for resources: 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;
/* Override defaults if the caller has supplied a privilege structure. */
if (m_ptr->CTL_ARG_PTR)
{
/* Copy s_flags. */
priv(rp)->s_flags = priv.s_flags;
/* Copy IRQs */
if(priv.s_flags & CHECK_IRQ) {
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];
#if 0
kprintf("do_privctl: adding IRQ %d for %d\n",
priv(rp)->s_irq_tab[i], rp->p_endpoint);
#endif
}
}
/* Copy I/O ranges */
if(priv.s_flags & CHECK_IO_PORT) {
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];
#if 0
kprintf("do_privctl: adding I/O range [%x..%x] for %d\n",
priv(rp)->s_io_tab[i].ior_base,
priv(rp)->s_io_tab[i].ior_limit,
rp->p_endpoint);
#endif
}
}
/* Copy memory ranges */
if(priv.s_flags & CHECK_MEM) {
if (priv.s_nr_mem_range < 0 || priv.s_nr_mem_range > NR_MEM_RANGE)
return EINVAL;
priv(rp)->s_nr_mem_range= priv.s_nr_mem_range;
for (i= 0; i<priv.s_nr_mem_range; i++)
{
priv(rp)->s_mem_tab[i]= priv.s_mem_tab[i];
#if 0
kprintf("do_privctl: adding mem range [%x..%x] for %d\n",
priv(rp)->s_mem_tab[i].mr_base,
priv(rp)->s_mem_tab[i].mr_limit,
rp->p_endpoint);
#endif
}
}
/* Copy trap mask. */
priv(rp)->s_trap_mask = priv.s_trap_mask;
/* Copy target mask. */
memcpy(&ipc_to_m, &priv.s_ipc_to, sizeof(ipc_to_m));
/* Copy kernel call mask. */
memcpy(priv(rp)->s_k_call_mask, priv.s_k_call_mask,
sizeof(priv(rp)->s_k_call_mask));
}
/* Fill in target mask. */
for (i=0; i < NR_SYS_PROCS; i++) {
if (ipc_to_m & (1 << i))
set_sendto_bit(rp, i);
else
unset_sendto_bit(rp, i);
}
return(OK);
case SYS_PRIV_SET_USER:
/* Set a privilege structure of a blocked user process. */
if (!RTS_ISSET(rp, RTS_NO_PRIV)) return(EPERM);
/* Link the process to the privilege structure of the root user
* process all the user processes share.
*/
priv(rp) = priv_addr(USER_PRIV_ID);
return(OK);
case SYS_PRIV_ADD_IO:
if (RTS_ISSET(rp, RTS_NO_PRIV))
return(EPERM);
/* Only system processes get I/O resources? */
if (!(priv(rp)->s_flags & SYS_PROC))
return EPERM;
#if 0 /* XXX -- do we need a call for this? */
if (strcmp(rp->p_name, "fxp") == 0 ||
strcmp(rp->p_name, "rtl8139") == 0)
{
kprintf("setting ipc_stats_target to %d\n", rp->p_endpoint);
ipc_stats_target= rp->p_endpoint;
}
#endif
/* Get the I/O range */
data_copy(who_e, (vir_bytes) m_ptr->CTL_ARG_PTR,
SYSTEM, (vir_bytes) &io_range, 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, RTS_NO_PRIV))
return(EPERM);
/* Only system processes get memory resources? */
if (!(priv(rp)->s_flags & SYS_PROC))
return EPERM;
/* Get the memory range */
if((r=data_copy(who_e, (vir_bytes) m_ptr->CTL_ARG_PTR,
SYSTEM, (vir_bytes) &mem_range, sizeof(mem_range))) != OK)
return r;
priv(rp)->s_flags |= CHECK_MEM; /* Check memory mappings */
i= priv(rp)->s_nr_mem_range;
if (i >= NR_MEM_RANGE)
return ENOMEM;
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++;
return OK;
case SYS_PRIV_ADD_IRQ:
if (RTS_ISSET(rp, RTS_NO_PRIV))
return(EPERM);
/* Only system processes get IRQs? */
if (!(priv(rp)->s_flags & SYS_PROC))
return EPERM;
data_copy(who_e, (vir_bytes) m_ptr->CTL_ARG_PTR,
SYSTEM, (vir_bytes) &irq, sizeof(irq));
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]= irq;
priv(rp)->s_nr_irq++;
return OK;
case SYS_PRIV_QUERY_MEM:
{
phys_bytes addr, limit;
struct priv *sp;
/* See if a certain process is allowed to map in certain physical
* memory.
*/
addr = (phys_bytes) m_ptr->CTL_PHYSSTART;
limit = addr + (phys_bytes) m_ptr->CTL_PHYSLEN - 1;
if(limit < addr)
return EPERM;
if(!(sp = priv(rp)))
return EPERM;
if (!(sp->s_flags & SYS_PROC))
return EPERM;
for(i = 0; i < sp->s_nr_mem_range; i++) {
if(addr >= sp->s_mem_tab[i].mr_base &&
limit <= sp->s_mem_tab[i].mr_limit)
return OK;
}
return EPERM;
}
default:
kprintf("do_privctl: bad request %d\n", m_ptr->CTL_REQUEST);
return EINVAL;
}
}
#endif /* USE_PRIVCTL */