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Simplified cap id finding and destroying it.

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It is not very straightforward to reach a capabilities list. We
now use a single function to find out a capability by its id and
its list, since the two are used frequently together (i.e. cap
removal and destruction)
This commit is contained in:
Bahadir Balban
2009-11-09 23:50:03 +02:00
parent ff14ce4735
commit d43fa1d3ae
3 changed files with 27 additions and 58 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
include/l4/generic/capability.h
View File

@@ -146,9 +146,7 @@ struct capability *capability_find_by_rtype(struct ktcb *task,
struct capability *cap_list_find_by_rtype(struct cap_list *clist,
unsigned int rtype);
struct capability *cap_find_byid(l4id_t capid);
int cap_find_destroy(l4id_t capid);
struct capability *cap_find_by_capid(l4id_t capid, struct cap_list **clist);
/* Capability checking on system calls */
int cap_map_check(struct ktcb *task, unsigned long phys, unsigned long virt,

25
src/api/cap.c
View File

@@ -61,15 +61,16 @@ int cap_read_all(struct capability *caparray)
int cap_share_single(l4id_t capid)
{
struct capability *cap;
struct cap_list *clist;
if (!(cap = cap_find_byid(capid)))
if (!(cap = cap_find_by_capid(capid, &clist)))
return -EEXIST;
if (cap->owner != current->tid)
return -EPERM;
/* First remove it from its list */
list_remove(&cap->list);
cap_list_remove(cap, clist);
/* Place it where it is shared */
cap_list_insert(cap, &curcont->cap_list);
@@ -145,9 +146,10 @@ out_err:
int cap_grant_single(struct capability *req, unsigned int flags)
{
struct capability *cap;
struct cap_list *clist;
struct ktcb *target;
if (!(cap = cap_find_byid(req->capid)))
if (!(cap = cap_find_by_capid(req->capid, &clist)))
return -EEXIST;
if (!(target = tcb_find(req->owner)))
@@ -161,7 +163,7 @@ int cap_grant_single(struct capability *req, unsigned int flags)
return -EPERM;
/* First remove it from its list */
list_remove(&cap->list);
cap_list_remove(cap, clist);
/* Change ownership */
cap->owner = target->tid;
@@ -272,10 +274,11 @@ int cap_deduce_rtype(struct capability *orig, struct capability *new)
int cap_deduce(struct capability *new)
{
struct capability *orig;
struct cap_list *clist;
int ret;
/* Find original capability */
if (!(orig = cap_find_byid(new->capid)))
if (!(orig = cap_find_by_capid(new->capid, &clist)))
return -EEXIST;
/* Check that caller is owner */
@@ -353,9 +356,10 @@ int cap_deduce(struct capability *new)
int cap_destroy(struct capability *cap)
{
struct capability *orig;
struct cap_list *clist;
/* Find original capability */
if (!(orig = cap_find_byid(cap->capid)))
if (!(orig = cap_find_by_capid(cap->capid, &clist)))
return -EEXIST;
/* Check that caller is owner */
@@ -366,7 +370,8 @@ int cap_destroy(struct capability *cap)
if (!(cap_generic_perms(orig) & CAP_CHANGEABLE))
return -ENOCAP;
cap_find_destroy(cap->capid);
cap_list_remove(orig, clist);
free_capability(orig);
return 0;
}
@@ -399,10 +404,11 @@ static inline int cap_has_range(struct capability *c)
int cap_split(struct capability *diff, unsigned int flags)
{
struct capability *orig, *new;
struct cap_list *clist;
int ret;
/* Find original capability */
if (!(orig = cap_find_byid(diff->capid)))
if (!(orig = cap_find_by_capid(diff->capid, &clist)))
return -EEXIST;
/* Check target type/resid/owner is the same */
@@ -576,9 +582,10 @@ out_err:
int cap_replicate(struct capability *dupl)
{
struct capability *new, *orig;
struct cap_list *clist;
/* Find original capability */
if (!(orig = cap_find_byid(dupl->capid)))
if (!(orig = cap_find_by_capid(dupl->capid, &clist)))
return -EEXIST;
/* Check that caller is owner */

56
src/generic/capability.c
View File

@@ -128,70 +128,35 @@ struct capability *capability_find_by_rtype(struct ktcb *task,
return 0;
}
/*
* FIXME: Make these functions pass a match function to cap_find()
* and remove all duplication. Same goes for find_rtype.
*/
struct capability *cap_find_byid(l4id_t capid)
struct capability *cap_find_by_capid(l4id_t capid, struct cap_list **cap_list)
{
struct capability *cap;
struct ktcb *task = current;
/* Search task's own list */
list_foreach_struct(cap, &task->cap_list.caps, list)
if (cap->capid == capid)
if (cap->capid == capid) {
*cap_list = &task->cap_list;
return cap;
}
/* Search space list */
list_foreach_struct(cap, &task->space->cap_list.caps, list)
if (cap->capid == capid)
if (cap->capid == capid) {
*cap_list = &task->space->cap_list;
return cap;
}
/* Search container list */
list_foreach_struct(cap, &task->container->cap_list.caps, list)
if (cap->capid == capid)
if (cap->capid == capid) {
*cap_list = &task->container->cap_list;
return cap;
}
return 0;
}
/*
* TODO: Instead of destroying, use cap_find_byid match function's
* match_args to pass a pointer to the capability list, so the
* caller may destroy it
*/
int cap_find_destroy(l4id_t capid)
{
struct capability *cap;
struct ktcb *task = current;
/* Search task's own list */
list_foreach_struct(cap, &task->cap_list.caps, list)
if (cap->capid == capid) {
cap_list_remove(cap, &task->cap_list);
free_capability(cap);
return 0;
}
/* Search space list */
list_foreach_struct(cap, &task->space->cap_list.caps, list)
if (cap->capid == capid) {
cap_list_remove(cap, &task->space->cap_list);
free_capability(cap);
return 0;
}
/* Search container list */
list_foreach_struct(cap, &task->container->cap_list.caps, list)
if (cap->capid == capid) {
cap_list_remove(cap, &task->container->cap_list);
free_capability(cap);
return 0;
}
return -EEXIST;
}
typedef struct capability *(*cap_match_func_t) \
(struct capability *cap, void *match_args);
@@ -543,7 +508,6 @@ struct capability *cap_match_thread(struct capability *cap,
if (!(cap->access & CAP_TCTRL_WAIT))
return 0;
break;
default:
/* We refuse to accept anything else */
return 0;