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. expanded grant manipulation interface to more direct

Browse source 
manipulation
. made fs allocate a grant for every ioctl, even if no data
  is being copied, in order to disambiguate concurrent ioctls
  on the same minor
This commit is contained in:
Ben Gras 2006-06-26 16:08:42 +00:00
parent 2f50f92eb3
commit a587273c56
3 changed files with 132 additions and 49 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

8
include/minix/safecopies.h
View file

@ -71,6 +71,14 @@ _PROTOTYPE( int cpf_revoke, (cp_grant_id_t grant_id));
_PROTOTYPE( int cpf_preallocate, (cp_grant_t *, int));
_PROTOTYPE( int cpf_lookup, (cp_grant_id_t g, endpoint_t *ep, endpoint_t *ep2));
_PROTOTYPE( int cpf_getgrants, (cp_grant_id_t *grant_ids, int n));
_PROTOTYPE( int cpf_setgrant_direct, (cp_grant_id_t g, endpoint_t who,
vir_bytes addr, size_t size, int access));
_PROTOTYPE( int cpf_setgrant_indirect, (cp_grant_id_t g, endpoint_t who_to,
endpoint_t who_from, cp_grant_id_t his_g));
_PROTOTYPE( int cpf_setgrant_magic, (cp_grant_id_t g, endpoint_t who_to,
endpoint_t who_from, vir_bytes addr, size_t bytes, int access));
/* Set a process' grant table location and size (in-kernel only). */
#define _K_SET_GRANT_TABLE(rp, ptr, entries) \
priv(rp)->s_grant_table= (ptr); \

149
lib/syslib/safecopies.c
View file

@ -15,6 +15,28 @@
#include <minix/com.h>
#include <string.h>
#define ACCESS_CHECK(a) { \
if((a) & ~(CPF_READ|CPF_WRITE)) { \
errno = EINVAL; \
return -1; \
} \
}
#define GID_CHECK(gid) { \
if(!GRANT_VALID(gid) || (gid) < 0 || (gid) >= ngrants) {\
errno = EINVAL; \
return -1; \
} \
}
#define GID_CHECK_USED(gid) { \
GID_CHECK(gid); \
if(!(grants[gid].cp_flags & CPF_USED)) { \
errno = EINVAL; \
return -1; \
} \
}
PRIVATE cp_grant_t *grants = NULL;
PRIVATE int ngrants = 0, dynamic = 1;
@ -147,26 +169,21 @@ PUBLIC cp_grant_id_t
cpf_grant_direct(endpoint_t who_to, vir_bytes addr, size_t bytes, int access)
{
cp_grant_id_t g;
int r;
/* Get new slot to put new grant in. */
if((g = cpf_new_grantslot()) < 0)
return -1;
/* Don't let caller specify any other flags than access. */
if(access & ~(CPF_READ|CPF_WRITE)) {
errno = EINVAL;
return -1;
}
assert(GRANT_VALID(g));
assert(g >= 0);
assert(g < ngrants);
assert(!(grants[g].cp_flags & CPF_USED));
grants[g].cp_flags = CPF_USED | CPF_DIRECT | access;
grants[g].cp_u.cp_direct.cp_who_to = who_to;
grants[g].cp_u.cp_direct.cp_start = addr;
grants[g].cp_u.cp_direct.cp_len = bytes;
if((r=cpf_setgrant_direct(g, who_to, addr, bytes, access)) < 0) {
cpf_revoke(g);
return GRANT_INVALID;
}
return g;
}
@ -178,6 +195,7 @@ cpf_grant_indirect(endpoint_t who_to, endpoint_t who_from, cp_grant_id_t gr)
* id 'gr'.
*/
cp_grant_id_t g;
int r;
/* Obtain new slot. */
if((g = cpf_new_grantslot()) < 0)
@ -190,10 +208,10 @@ cpf_grant_indirect(endpoint_t who_to, endpoint_t who_from, cp_grant_id_t gr)
assert(!(grants[g].cp_flags & CPF_USED));
/* Fill in new slot data. */
grants[g].cp_flags = CPF_USED | CPF_INDIRECT;
grants[g].cp_u.cp_indirect.cp_who_to = who_to;
grants[g].cp_u.cp_indirect.cp_who_from = who_from;
grants[g].cp_u.cp_indirect.cp_grant = gr;
if((r=cpf_setgrant_indirect(g, who_to, who_from, gr)) < 0) {
cpf_revoke(g);
return GRANT_INVALID;
}
return g;
}
@ -204,6 +222,9 @@ cpf_grant_magic(endpoint_t who_to, endpoint_t who_from,
{
/* Grant process A access into process B. Not everyone can do this. */
cp_grant_id_t g;
int r;
ACCESS_CHECK(access);
/* Obtain new slot. */
if((g = cpf_new_grantslot()) < 0)
@ -215,19 +236,12 @@ cpf_grant_magic(endpoint_t who_to, endpoint_t who_from,
assert(g < ngrants);
assert(!(grants[g].cp_flags & CPF_USED));
/* Don't let caller specify any other flags than access. */
if(access & ~(CPF_READ|CPF_WRITE)) {
errno = EINVAL;
if((r=cpf_setgrant_magic(g, who_to, who_from, addr,
bytes, access)) < 0) {
cpf_revoke(g);
return -1;
}
/* Fill in new slot data. */
grants[g].cp_flags = CPF_USED | CPF_MAGIC | access;
grants[g].cp_u.cp_magic.cp_who_to = who_to;
grants[g].cp_u.cp_magic.cp_who_from = who_from;
grants[g].cp_u.cp_magic.cp_start = addr;
grants[g].cp_u.cp_magic.cp_len = bytes;
return g;
}
@ -235,11 +249,7 @@ PUBLIC int
cpf_revoke(cp_grant_id_t g)
{
/* Revoke previously granted access, identified by grant id. */
/* First check slot validity, and if it's in use currently. */
if(g < 0 || g >= ngrants || !(grants[g].cp_flags & CPF_USED)) {
errno = EINVAL;
return -1;
}
GID_CHECK_USED(g);
/* Make grant invalid by setting flags to 0, clearing CPF_USED.
* This invalidates the grant.
@ -253,11 +263,7 @@ PUBLIC int
cpf_lookup(cp_grant_id_t g, endpoint_t *granter, endpoint_t *grantee)
{
/* First check slot validity, and if it's in use currently. */
if(!GRANT_VALID(g) ||
g < 0 || g >= ngrants || !(grants[g].cp_flags & CPF_USED)) {
errno = EINVAL;
return -1;
}
GID_CHECK_USED(g);
if(grants[g].cp_flags & CPF_DIRECT) {
if(granter) *granter = SELF;
@ -270,3 +276,78 @@ cpf_lookup(cp_grant_id_t g, endpoint_t *granter, endpoint_t *grantee)
return 0;
}
PUBLIC int
cpf_getgrants(grant_ids, n)
cp_grant_id_t *grant_ids;
int n;
{
cp_grant_id_t g;
int i;
for(i = 0; i < n; i++) {
if((grant_ids[i] = cpf_new_grantslot()) < 0)
break;
cpf_revoke(grant_ids[i]);
}
/* return however many grants were assigned. */
return i;
}
PUBLIC int
cpf_setgrant_direct(gid, who, addr, bytes, access)
cp_grant_id_t gid;
endpoint_t who;
vir_bytes addr;
size_t bytes;
int access;
{
GID_CHECK(gid);
ACCESS_CHECK(access);
grants[gid].cp_flags = access | CPF_DIRECT | CPF_USED;
grants[gid].cp_u.cp_direct.cp_who_to = who;
grants[gid].cp_u.cp_direct.cp_start = addr;
grants[gid].cp_u.cp_direct.cp_len = bytes;
return 0;
}
PUBLIC int
cpf_setgrant_indirect(gid, who_to, who_from, his_gid)
cp_grant_id_t gid;
endpoint_t who_to, who_from;
cp_grant_id_t his_gid;
{
GID_CHECK(gid);
/* Fill in new slot data. */
grants[gid].cp_flags = CPF_USED | CPF_INDIRECT;
grants[gid].cp_u.cp_indirect.cp_who_to = who_to;
grants[gid].cp_u.cp_indirect.cp_who_from = who_from;
grants[gid].cp_u.cp_indirect.cp_grant = his_gid;
return 0;
}
PUBLIC int
cpf_setgrant_magic(gid, who_to, who_from, addr, bytes, access)
cp_grant_id_t gid;
endpoint_t who_to, who_from;
vir_bytes addr;
size_t bytes;
int access;
{
GID_CHECK(gid);
ACCESS_CHECK(access);
/* Fill in new slot data. */
grants[gid].cp_flags = CPF_USED | CPF_MAGIC | access;
grants[gid].cp_u.cp_magic.cp_who_to = who_to;
grants[gid].cp_u.cp_magic.cp_who_from = who_from;
grants[gid].cp_u.cp_magic.cp_start = addr;
grants[gid].cp_u.cp_magic.cp_len = bytes;
return 0;
}

24
servers/fs/device.c
View file

@ -178,14 +178,6 @@ off_t *pos;
int m, j;
iovec_t *v;
/* Is this device driver (identified by major number)
* ready to accept *_S commands?
*/
#if 0
if(major(dev) == 7) /* major number of inet. */
return 0; /* inet is not safe-capable. */
#endif
/* Number of grants allocated in vector I/O. */
*vec_grants = 0;
@ -239,13 +231,15 @@ off_t *pos;
if(_MINIX_IOCTL_IOR(m_in.REQUEST)) access |= CPF_WRITE;
if(_MINIX_IOCTL_IOW(m_in.REQUEST)) access |= CPF_READ;
size = _MINIX_IOCTL_SIZE(m_in.REQUEST);
if(access && size > 0) {
if((*gid=cpf_grant_magic(driver, *io_ept,
(vir_bytes) buf, size, access)) < 0) {
panic(__FILE__,
"cpf_grant_magic failed (ioctl)\n",
NO_NUM);
}
/* Do this even if no I/O happens with the ioctl, in
* order to disambiguate requests with DEV_IOCTL_S.
*/
if((*gid=cpf_grant_magic(driver, *io_ept,
(vir_bytes) buf, size, access)) < 0) {
panic(__FILE__,
"cpf_grant_magic failed (ioctl)\n",
NO_NUM);
}
}