Add header checksum

4 files changed, 15 insertions, 7 deletions

diff --git a/include/common.h b/include/common.h
index cfb454e..9b54143 100644
--- a/include/common.h
+++ b/include/common.h
@@ -6,6 +6,7 @@ int nfl_check_dir(const char *storage_dir);
 int nfl_storage_match_index(const char *fn);
 const char *nfl_get_filename(const char *dir, int id);
 uint32_t nfl_get_filesize(FILE *f);
+uint32_t nfl_header_cksum(nflog_header_t *header);
 void nfl_cal_trunk(uint32_t total_size, uint32_t *trunk_cnt,
                    uint32_t *trunk_size);
 void nfl_cal_entries(uint32_t trunk_size, uint32_t *entries_cnt);
diff --git a/lib/collect.c b/lib/collect.c
index b7cf430..a8a46bd 100644
--- a/lib/collect.c
+++ b/lib/collect.c
@@ -160,6 +160,9 @@ void *nfl_collect_worker(void *targs) {
     nflog_unbind_group(nf->nfl_group_fd);
     nflog_close(nf->nfl_fd);
 
+    // write checksum
+    nf->header->cksum = nfl_header_cksum(nf->header);
+
     // spawn commit thread
     nfl_commit(nf);
     pthread_exit(NULL);
diff --git a/lib/common.c b/lib/common.c
index 804b803..344f531 100644
--- a/lib/common.c
+++ b/lib/common.c
@@ -72,14 +72,14 @@ uint32_t nfl_get_filesize(FILE *f) {
 }
 
 uint32_t nfl_header_cksum(nflog_header_t *header) {
+    #define H(s) (0x9e3779b9 + (s<< 6) + (s>> 1))
     register uint64_t s = 3784672181;
-    s += header->id;
-    s ^= header->max_n_entries;
-    s += header->n_entries;
-    s ^= header->start_time;
-    s += header->end_time;
-    s &= UINT_MAX;
-    return s;
+    s ^= H(header->id);
+    s ^= H(header->max_n_entries);
+    s ^= H(header->n_entries);
+    s ^= H(header->start_time);
+    s ^= H(header->end_time);
+    return s & UINT_MAX;
 }
 
 void nfl_cal_trunk(uint32_t total_size, uint32_t *trunk_cnt,
diff --git a/lib/extract.c b/lib/extract.c
index dfb7223..be8dbc4 100644
--- a/lib/extract.c
+++ b/lib/extract.c
@@ -11,6 +11,9 @@ static int nfl_extract_zstd(FILE *f, nflog_state_t *state);
 static int nfl_extract_lz4(FILE *f, nflog_state_t *state);
 
 static int nfl_verify_header(nflog_header_t *header) {
+    if(header->cksum != nfl_header_cksum(header))
+        return -1;
+
     if (header->id > MAX_TRUNK_ID)
         return -1;
 
@@ -21,6 +24,7 @@ static int nfl_verify_header(nflog_header_t *header) {
     if ((time_t)header->start_time >= now || (time_t)header->end_time >= now ||
         header->start_time > header->end_time)
         return -1;
+
     return 0;
 }