bitwises

bitprint.h

@@ -0,0 +1,41 @@
+// https://stackoverflow.com/a/39401342/2776344
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include <limits.h>
+
+#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+#define for_endian(size) for (int i = 0; i < size; ++i)
+#elif __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+#define for_endian(size) for (int i = size - 1; i >= 0; --i)
+#else
+#error "Endianness not detected"
+#endif
+
+#define printb(value) \
+({ \
+ typeof(value) _v = value; \
+ __printb((typeof(_v) *) &_v, sizeof(_v)); \
+})
+
+#define MSB_MASK 1 << (CHAR_BIT - 1)
+
+void __printb(void *value, size_t size)
+{
+ unsigned char uc;
+ unsigned char bits[CHAR_BIT + 1];
+
+ bits[CHAR_BIT] = '\0';
+ for_endian(size) {
+ uc = ((unsigned char *) value)[i];
+ memset(bits, '0', CHAR_BIT);
+ for (int j = 0; uc && j < CHAR_BIT; ++j) {
+ if (uc & MSB_MASK)
+ bits[j] = '1';
+ uc <<= 1;
+ }
+ printf("%s ", bits);
+ }
+ printf("\n");
+}

mlt-scp.c

@@ -0,0 +1,136 @@
+#include <stdbool.h>
+#include <stdlib.h>
+
+#include "bitprint.h"
+
+#define MAX_SCOPES 32
+
+#define UID_FILTER 1 << 0
+#define PID_FILTER 1 << 1
+#define UTS_NS_FILTER 1 << 2
+#define COMM_FILTER 1 << 3
+
+typedef struct filter_scope {
+ bool uid;
+ bool pid;
+ bool uts_ns;
+ bool comm;
+} filter_scope_t;
+
+typedef struct config_entry {
+ uint32_t uid_filter_enabled;
+ uint32_t pid_filter_enabled;
+ uint32_t uts_ns_filter_enabled;
+ uint32_t comm_filter_enabled;
+
+ uint32_t uid_filter_out;
+ uint32_t pid_filter_out;
+ uint32_t uts_ns_filter_out;
+ uint32_t comm_filter_out;
+
+ uint32_t enabled_scopes;
+} config_entry_t;
+
+void
+print_filter_scopes(filter_scope_t **fscopes)
+{
+ if (!fscopes)
+ return;
+
+ printf(">>> Filter Scopes\n");
+ for (int i = 0; i < MAX_SCOPES; i++) {
+ filter_scope_t *fs = fscopes[i];
+ if (!fs)
+ continue;
+
+ printf(" > [%d] %p - %u %u %u %u\n", i+1, fs,
+ fs->uid,
+ fs->pid,
+ fs->uts_ns,
+ fs->comm
+ );
+ }
+ printf("\n");
+}
+
+void
+set_filter_scope(filter_scope_t *fscope, uint32_t filters)
+{
+ if (!fscope)
+ return;
+
+ fscope->uid = !!(filters & UID_FILTER);
+ fscope->pid = !!(filters & PID_FILTER);
+ fscope->uts_ns = !!(filters & UTS_NS_FILTER);
+ fscope->comm = !!(filters & COMM_FILTER);
+}
+
+filter_scope_t *
+new_filter_scope(uint32_t filters)
+{
+ filter_scope_t *fscope = malloc(sizeof(filter_scope_t));
+ if (!fscope)
+ return NULL;
+
+ set_filter_scope(fscope, filters);
+
+ return fscope;
+}
+
+void set_config_entry(config_entry_t *ce, filter_scope_t **fscopes)
+{
+ if (!ce || !fscopes)
+ return;
+
+ printf(">>> Setting Config Entry\n");
+ for (int i = 0; i < MAX_SCOPES; i++) {
+ filter_scope_t *fs = fscopes[i];
+ if (!fs)
+ continue;
+
+ uint32_t scope_enabled = fscopes[i]->uid |
+ fscopes[i]->pid |
+ fscopes[i]->uts_ns |
+ fscopes[i]->comm;
+
+ if (!scope_enabled)
+ continue;
+
+ ce->uid_filter_enabled |= (fscopes[i]->uid << i);
+ ce->pid_filter_enabled |= (fscopes[i]->pid << i);
+ ce->uts_ns_filter_enabled |= (fscopes[i]->uts_ns << i);
+ ce->comm_filter_enabled |= (fscopes[i]->comm << i);
+ ce->enabled_scopes |= (1 << i);
+ }
+
+ printf(" * enabled_scopes:%*s", 30, " ");
+ printb(ce->enabled_scopes);
+ printf(" > uid_filter_enabled in scope%*s", 10, "\t");
+ printb(ce->uid_filter_enabled);
+ printf(" > pid_filter_enabled in scope%*s", 10, "\t");
+ printb(ce->pid_filter_enabled);
+ printf(" > uts_ns_filter_enabled in scope%*s", 10, "\t");
+ printb(ce->uts_ns_filter_enabled);
+ printf(" > comm_filter_enabled in scope%*s", 10, "\t");
+ printb(ce->comm_filter_enabled);
+ printf("\n");
+}
+
+int
+main(void)
+{
+ filter_scope_t *fscopes[MAX_SCOPES] = {
+ new_filter_scope(UID_FILTER),
+ new_filter_scope(PID_FILTER | COMM_FILTER),
+ new_filter_scope(0),
+ new_filter_scope(UTS_NS_FILTER),
+ new_filter_scope(PID_FILTER)
+ };
+
+ print_filter_scopes(fscopes);
+
+ config_entry_t ce = {};
+ set_config_entry(&ce, fscopes);
+
+ return 0;
+}