minix/kernel/ipc_filter.h

   1 #ifndef IPC_FILTER_H
   2 #define IPC_FILTER_H
   3
   4 /* Declaration of the ipc filter structure. It provides a framework to
   5  * selectively allow/disallow ipc messages a process agrees to receive. To this
   6  * end, a single ipc filter can be specified at a given time for any recipient
   7  * to blacklist/whitelist a set of ipc messages identified by sender or message
   8  * type.
   9  */
  10 #include <minix/ipc_filter.h>
  11
  12 /* IPC filter types. */
  13 #define IPCF_NONE        0      /* no ipc filter */
  14 #define IPCF_BLACKLIST   1      /* blacklist filter type */
  15 #define IPCF_WHITELIST   2      /* whitelist filter type */
  16
  17 /* IPC filter element macros. */
  18 EXTERN int _ipcf_nr;
  19 #define IPCF_EL_CHECK(E) \
  20         ((((E)->flags & IPCF_MATCH_M_TYPE) || \
  21         ((E)->flags & IPCF_MATCH_M_SOURCE)) && \
  22         (!((E)->flags & IPCF_MATCH_M_SOURCE) || \
  23         IPCF_IS_ANY_EP((E)->m_source) || isokendpt((E)->m_source, &_ipcf_nr)))
  24 #define IPCF_IS_USR_EP(EP) \
  25         (!(priv(proc_addr(_ENDPOINT_P((EP))))->s_flags & SYS_PROC))
  26 #define IPCF_IS_TSK_EP(EP) (iskerneln(_ENDPOINT_P((EP))))
  27 #define IPCF_IS_SYS_EP(EP) (!IPCF_IS_USR_EP(EP) && !IPCF_IS_TSK_EP(EP))
  28 #define IPCF_IS_ANY_EP(EP) \
  29         ((EP) == ANY_USR || (EP) == ANY_SYS || (EP) == ANY_TSK)
  30 #define IPCF_EL_MATCH_M_TYPE(E,M) \
  31         (!((E)->flags & IPCF_MATCH_M_TYPE) || (E)->m_type == (M)->m_type)
  32 #define IPCF_EL_MATCH_M_SOURCE(E,M) \
  33         (!((E)->flags & IPCF_MATCH_M_SOURCE) || \
  34         (E)->m_source == (M)->m_source || \
  35         IPCF_EL_MATCH_M_SOURCE_ANY_EP((E)->m_source,(M)->m_source))
  36 #define IPCF_EL_MATCH_M_SOURCE_ANY_EP(ES,MS) \
  37         (((ES) == ANY_USR && IPCF_IS_USR_EP(MS)) || \
  38         ((ES) == ANY_SYS && IPCF_IS_SYS_EP(MS)) || \
  39         ((ES) == ANY_TSK && IPCF_IS_TSK_EP(MS)))
  40 #define IPCF_EL_MATCH(E,M) \
  41         (IPCF_EL_MATCH_M_TYPE(E,M) && IPCF_EL_MATCH_M_SOURCE(E,M))
  42
  43 struct ipc_filter_s {
  44   int type;
  45   int num_elements;
  46   int flags;
  47   struct ipc_filter_s *next;
  48   ipc_filter_el_t elements[IPCF_MAX_ELEMENTS];
  49 };
  50 typedef struct ipc_filter_s ipc_filter_t;
  51
  52 /* IPC filter pool. */
  53 #define IPCF_POOL_SIZE          (2*NR_SYS_PROCS)
  54 EXTERN ipc_filter_t ipc_filter_pool[IPCF_POOL_SIZE];
  55
  56 /* IPC filter pool macros. */
  57 #define IPCF_POOL_FREE_SLOT(S) ((S)->type = IPCF_NONE)
  58 #define IPCF_POOL_IS_FREE_SLOT(S) ((S)->type == IPCF_NONE)
  59 #define IPCF_POOL_ALLOCATE_SLOT(T,S) \
  60         do { \
  61                 int i; \
  62                 *(S) = NULL; \
  63                 for (i = 0; i < IPCF_POOL_SIZE; i++) { \
  64                         if (IPCF_POOL_IS_FREE_SLOT(&ipc_filter_pool[i])) { \
  65                                 *(S) = &ipc_filter_pool[i]; \
  66                                 (*(S))->type = T; \
  67                                 break; \
  68                         } \
  69                 } \
  70         } while(0)
  71 #define IPCF_POOL_INIT(S) memset(&ipc_filter_pool,0,sizeof(ipc_filter_pool))
  72
  73 #endif /* !IPC_FILTER_H */