/*
* construct SetupList (policy) part of manifest structure (w/o channels)
* note: malloc(). must be called only once
*/
void SetupUserPolicy(struct NaClApp *nap)
{
/* allocate space for policy */
struct SetupList *policy = malloc(sizeof(*policy));
COND_ABORT(!policy, "cannot allocate memory for user policy\n");
policy->self_size = sizeof(*policy); /* set self size */
/* setup limits */
TRANSET(policy->max_cpu, "CPUMax");
TRANSET(policy->max_mem, "MemMax");
TRANSET(policy->max_setup_calls, "SetupCallsMax");
TRANSET(policy->max_syscalls, "SyscallsMax");
/* setup counters */
policy->cnt_cpu = 0;
policy->cnt_cpu_last = 0;
policy->cnt_mem = 0;
policy->cnt_setup_calls = 0;
policy->cnt_syscalls = 0;
policy->heap_ptr = 0; /* set user heap to NULL until it allocated */
/* clear syscallback */
policy->syscallback = 0;
/* setup custom attributes */
#define STRNCPY_NULL(a, b, n) if ((a) && (b)) strncpy(a, b, n);
STRNCPY_NULL(policy->content_type, get_value_by_key(nap, "ContentType"), CONTENT_TYPE_LEN);
STRNCPY_NULL(policy->timestamp, get_value_by_key(nap, "TimeStamp"), TIMESTAMP_LEN);
STRNCPY_NULL(policy->x_object_meta_tag, get_value_by_key(nap, "XObjectMetaTag"), X_OBJECT_META_TAG_LEN);
STRNCPY_NULL(policy->user_etag, get_value_by_key(nap, "UserETag"), USER_TAG_LEN);
#undef STRNCPY_NULL
nap->manifest->user_setup = policy;
}
/*
* user request to change limits for system resources. for now we only can decrease bounds
* return: function update given SetupList object (hint) and if there were
* unsuccessful attempt to change policy return -1, otherwirse return 0
*/
static int32_t TrapUserSetupHandle(struct NaClApp *nap, struct SetupList *h)
{
struct PreOpenedFileDesc *policy_channel;
struct PreOpenedFileDesc *hint_channel;
struct SetupList *policy = nap->manifest->user_setup;
struct SetupList *hint = (struct SetupList*)NaClUserToSys(nap, (intptr_t) h);
int32_t retcode = OK_CODE;
enum ChannelType ch;
/*
* check/count this call. decrease number of syscalls
* since this call is not really "system"
*/
--nap->manifest->user_setup->cnt_syscalls;
if(policy->max_setup_calls < ++policy->cnt_setup_calls)
return -OUT_OF_LIMITS;
/* check i/o limits */
for(ch = InputChannel; ch < CHANNELS_COUNT; ++ch)
{
/* pick current channel settings */
policy_channel = &policy->channels[ch];
hint_channel = &hint->channels[ch];
hint_channel->self_size = policy_channel->self_size; /* set self size */
#define STRNCPY_NULL(a, b, n) if ((a) && (b)) strncpy((a), (b), (n));
#define TRY_UPDATE(pretender, current)\
do {\
if(policy->cnt_setup_calls == 1) { pretender = current; break; }\
if((pretender) < (current)) current = pretender;\
else { pretender = current; retcode = ERR_CODE; }\
} while(0)
/* check/update i/o limits. 1st time - set fields in hint */
TRY_UPDATE(hint_channel->max_size, policy_channel->max_size);
TRY_UPDATE(hint_channel->max_get_size, policy_channel->max_get_size);
TRY_UPDATE(hint_channel->max_gets, policy_channel->max_gets);
TRY_UPDATE(hint_channel->max_put_size, policy_channel->max_put_size);
TRY_UPDATE(hint_channel->max_puts, policy_channel->max_puts);
/* set i/o fields n/a to change */
hint_channel->bsize = policy_channel->bsize;
hint_channel->buffer = policy_channel->buffer;
hint_channel->fsize = policy_channel->fsize;
hint_channel->type = policy_channel->type;
}
/* check/update system limits. 1st time - set fields in hint */
TRY_UPDATE(hint->max_cpu, policy->max_cpu);
TRY_UPDATE(hint->max_mem, policy->max_mem); /* ### call unmap here? */
TRY_UPDATE(hint->max_syscalls, policy->max_syscalls);
TRY_UPDATE(hint->max_setup_calls, policy->max_setup_calls);
/* set system fields n/a to change */
hint->self_size = policy->self_size; /* set self size */
hint->heap_ptr = policy->heap_ptr; /* set self size */
STRNCPY_NULL(hint->content_type, policy->content_type, CONTENT_TYPE_LEN);
STRNCPY_NULL(hint->timestamp, policy->timestamp, TIMESTAMP_LEN);
STRNCPY_NULL(hint->user_etag, policy->user_etag, USER_TAG_LEN);
STRNCPY_NULL(hint->x_object_meta_tag, policy->x_object_meta_tag, X_OBJECT_META_TAG_LEN);
/* update syscallback */
if(UpdateSyscallback(nap, hint) == ERR_CODE) retcode = ERR_CODE;
#undef STRNCPY_NULL
#undef TRY_UPDATE
return retcode;
}
