c51cd5fe91
Before safecopies, the IO_ENDPT and DL_ENDPT message fields were needed to know which actual process to copy data from/to, as that process may not always be the caller. Now that we have full safecopy support, these fields have become useless for that purpose: the owner of the grant is *always* the caller. Allowing the caller to supply another endpoint is in fact dangerous, because the callee may then end up using a grant from a third party. One could call this a variant of the confused deputy problem. From now on, safecopy calls should always use the caller's endpoint as grant owner. This fully obsoletes the DL_ENDPT field in the inet/ethernet protocol. IO_ENDPT has other uses besides identifying the grant owner though. This patch renames IO_ENDPT to USER_ENDPT, not only because that is a more fitting name (it should never be used for I/O after all), but also in order to intentionally break any old system source code outside the base system. If this patch breaks your code, fixing it is fairly simple: - DL_ENDPT should be replaced with m_source; - IO_ENDPT should be replaced with m_source when used for safecopies; - IO_ENDPT should be replaced with USER_ENDPT for any other use, e.g. when setting REP_ENDPT, matching requests in CANCEL calls, getting DEV_SELECT flags, and retrieving of the real user process's endpoint in DEV_OPEN. The changes in this patch are binary backward compatible.
99 lines
3.2 KiB
C
99 lines
3.2 KiB
C
#include "log.h"
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/* State management variables. */
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#define NR_DEVS 1 /* number of minor devices */
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EXTERN struct logdevice logdevices[NR_DEVS];
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/* State management helpers. */
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PRIVATE int is_read_pending;
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PRIVATE int is_select_callback_pending;
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PRIVATE void load_state_info(void)
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{
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int i, found_pending;
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struct logdevice *log;
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/* Check if reads or select callbacks are pending. */
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is_read_pending = FALSE;
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is_select_callback_pending = FALSE;
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found_pending = FALSE;
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for (i = 0; i < NR_DEVS && !found_pending; i++) {
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log = &logdevices[i];
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if(log->log_source != NONE) {
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is_read_pending = TRUE;
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}
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if(log->log_selected) {
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is_select_callback_pending = TRUE;
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}
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found_pending = (is_read_pending && is_select_callback_pending);
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}
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}
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/* Custom states definition. */
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#define LOG_STATE_SELECT_PROTOCOL_FREE (SEF_LU_STATE_CUSTOM_BASE + 0)
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#define LOG_STATE_IS_CUSTOM(s) ((s) == LOG_STATE_SELECT_PROTOCOL_FREE)
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/*===========================================================================*
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* sef_cb_lu_prepare *
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*===========================================================================*/
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PUBLIC int sef_cb_lu_prepare(int state)
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{
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int is_ready;
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/* Load state information. */
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load_state_info();
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/* Check if we are ready for the target state. */
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is_ready = FALSE;
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switch(state) {
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/* Standard states. */
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case SEF_LU_STATE_REQUEST_FREE:
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is_ready = (!is_read_pending);
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break;
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case SEF_LU_STATE_PROTOCOL_FREE:
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is_ready = (!is_read_pending && !is_select_callback_pending);
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break;
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/* Custom states. */
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case LOG_STATE_SELECT_PROTOCOL_FREE:
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is_ready = (!is_select_callback_pending);
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break;
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}
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/* Tell SEF if we are ready. */
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return is_ready ? OK : ENOTREADY;
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}
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/*===========================================================================*
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* sef_cb_lu_state_isvalid *
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*===========================================================================*/
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PUBLIC int sef_cb_lu_state_isvalid(int state)
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{
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return SEF_LU_STATE_IS_STANDARD(state) || LOG_STATE_IS_CUSTOM(state);
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}
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/*===========================================================================*
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* sef_cb_lu_state_dump *
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*===========================================================================*/
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PUBLIC void sef_cb_lu_state_dump(int state)
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{
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/* Load state information. */
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load_state_info();
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sef_lu_dprint("log: live update state = %d\n", state);
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sef_lu_dprint("log: is_read_pending = %d\n", is_read_pending);
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sef_lu_dprint("log: is_select_callback_pending = %d\n",
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is_select_callback_pending);
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sef_lu_dprint("log: SEF_LU_STATE_WORK_FREE(%d) reached = %d\n",
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SEF_LU_STATE_WORK_FREE, TRUE);
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sef_lu_dprint("log: SEF_LU_STATE_REQUEST_FREE(%d) reached = %d\n",
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SEF_LU_STATE_REQUEST_FREE, (!is_read_pending));
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sef_lu_dprint("log: SEF_LU_STATE_PROTOCOL_FREE(%d) reached = %d\n",
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SEF_LU_STATE_PROTOCOL_FREE, (!is_read_pending
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&& !is_select_callback_pending));
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sef_lu_dprint("log: LOG_STATE_SELECT_PROTOCOL_FREE(%d) reached = %d\n",
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LOG_STATE_SELECT_PROTOCOL_FREE, (!is_select_callback_pending));
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}
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