Changeset 1278

Timestamp:

14/09/07 16:05:43 (1 year ago)

Author:

smr26

Message:

Allow libtrace applications to create filters based on pre-compiled BPF
bytecode as well as filterstrings. See trace_create_filter_from_bytecode()

Files:

• trunk/lib/format_linux.c (modified) (3 diffs)
• trunk/lib/format_pcap.c (modified) (1 diff)
• trunk/lib/libtrace.h.in (modified) (2 diffs)
• trunk/lib/trace.c (modified) (1 diff)

trunk/lib/format_linux.c

@@ -51 +51 @@
-#include <errno.h>
-
+#include <assert.h>
-
-struct libtrace_format_data_t {
@@ -161 +162 @@
-        }
-
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-         */
-        if (filter != NULL) {
+                assert(filter->flag == 1);
-                if (setsockopt(FORMAT(libtrace->format_data)->fd,
-                                        SOL_SOCKET,
@@ -234 +238 @@
-        pcap_t *pcap;
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-        f = (libtrace_filter_t *) malloc(sizeof(libtrace_filter_t));
-        memcpy(f, filter, sizeof(libtrace_filter_t));
-
-        pcap = pcap_open_dead(dlt, FORMAT(libtrace->format_data)->snaplen);
-        
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-        if (FORMAT(libtrace->format_data)->filter != NULL)
-                free(FORMAT(libtrace->format_data)->filter);
-        
-        FORMAT(libtrace->format_data)->filter = f;
+        
-        return 0;
-#else

trunk/lib/format_pcap.c

@@ -104 +104 @@
-        }
-        if (DATA(libtrace)->filter) {
-
-
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-                if (pcap_setfilter(INPUT.pcap,&DATA(libtrace)->filter->filter) 
-                                == -1) {

trunk/lib/libtrace.h.in

@@ -1528 +1528 @@
-libtrace_filter_t *trace_create_filter(const char *filterstring);
-
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- * @param filter        the filter opaque pointer
- * @param packet        the packet opaque pointer
@@ -1541 +1551 @@
-                const libtrace_packet_t *packet);
-
-destory of
+Destroy a
- * @param filter        the filter opaque pointer
- * Deallocate all the resources associated with a BPF filter

trunk/lib/trace.c

@@ -964 +964 @@
-}
-
+/** Setup a BPF filter based on pre-compiled byte-code.
+ * @param bf_insns      A pointer to the start of the byte-code
+ * @param bf_len        The number of BPF instructions
+ * @returns             an opaque pointer to a libtrace_filter_t object
+ * @note                The supplied byte-code is not checked for correctness.
+ * @author              Scott Raynel
+ */
+DLLEXPORT libtrace_filter_t *
+trace_create_filter_from_bytecode(void *bf_insns, unsigned int bf_len)
+{
+#ifndef HAVE_BPF
+        fprintf(stderr, "This version of libtrace does not have BPF support\n");
+        return NULL;
+#else
+        struct libtrace_filter_t *filter = (struct libtrace_filter_t *)
+                malloc(sizeof(struct libtrace_filter_t));
+        filter->filter.bf_insns = (struct bpf_insn *)
+                malloc(sizeof(struct bpf_insn) * bf_len);
+        
+        memcpy(filter->filter.bf_insns, bf_insns,
+                        bf_len * sizeof(struct bpf_insn));
+        
+        filter->filter.bf_len = bf_len;
+        filter->filterstring = NULL;
+        /* "flag" indicates that the filter member is valid */
+        filter->flag = 1; 
+        
+        return filter;
+#endif
+}
+
-/* setup a BPF filter
- * @param filterstring a char * containing the bpf filter string