Prefix recording metadata and pcap files with call id

We want to be able to associate call files with a call without the
presence of identifying metadata within the metadata file. To accomplish
this, we prepend the call-id to the start of the pcap recording files
and the call metadata files.

Even though call-id is supposed to be unique, because of paranoia we
keep some of the random affix hex string, but we reduced it down to an
8-byte random value.

Also, some minor argument ordering and name refactoring for random
string generation functions.

daemon/call.c

@@ -1524,7 +1524,7 @@ int monologue_offer_answer(struct call_monologue *other_ml, GQueue *streams,
 	ml_media = other_ml_media = NULL;
 
 	if (call->recording != NULL && call->recording->recording_pdumper == NULL) {
-		str *pcap_path = recording_setup_file(call->recording);
+		str *pcap_path = recording_setup_file(call->recording, call->callid);
 		if (pcap_path != NULL && call->recording->recording_pdumper != NULL
 				&& call->recording->meta_fp) {
 			// Write the location of the PCAP file to the metadata file

daemon/call_interfaces.c

@@ -694,7 +694,7 @@ static const char *call_offer_answer_ng(bencode_item_t *input, struct callmaster
 			call->recording = g_slice_alloc0(sizeof(struct recording));
 			call->recording->recording_pd = NULL;
 			call->recording->recording_pdumper = NULL;
-			meta_setup_file(call->recording);
+			meta_setup_file(call->recording, call->callid);
 		}
 		bencode_dictionary_get_str(input, "metadata", &metadata);
 		if (metadata.len > 0) {

daemon/recording.c

@@ -97,16 +97,20 @@ int maybe_create_spool_dir(char *spoolpath) {
  * Create a call metadata file in a temporary location.
  * Attaches the filepath and the file pointer to the call struct.
  */
-str *meta_setup_file(struct recording *recording) {
+str *meta_setup_file(struct recording *recording, str callid) {
 	if (spooldir == NULL) {
 		// No spool directory was created, so we cannot have metadata files.
 		return NULL;
 	}
 	else {
-		int rand_bytes = 16;
+		int rand_bytes = 8;
 		str *meta_filepath = malloc(sizeof(str));
+		int mid_len = 20 + callid.len + 1 + 1;
+		// Length for spool directory path + "/tmp/rtpengine-meta-${CALLID}-"
+		char suffix_chars[mid_len];
+		snprintf(suffix_chars, mid_len, "/tmp/rtpengine-meta-%s-", callid.s);
 		// Initially file extension is ".tmp". When call is over, it changes to ".txt".
-		char *path_chars = rand_affixed_str(rand_bytes, "/tmp/rtpengine-meta-", ".tmp");
+		char *path_chars = rand_affixed_str(suffix_chars, rand_bytes, ".tmp");
 		meta_filepath = str_init(meta_filepath, path_chars);
 		recording->meta_filepath = meta_filepath;
 		FILE *mfp = fopen(meta_filepath->s, "w");
@@ -193,17 +197,19 @@ int meta_finish_file(struct call *call) {
 
 /**
  * Generate a random PCAP filepath to write recorded RTP stream.
+ * Returns path to created file.
  */
-str *recording_setup_file(struct recording *recording) {
+str *recording_setup_file(struct recording *recording, str callid) {
 	str *recording_path = NULL;
 	if (spooldir != NULL
       && recording != NULL
 	    && recording->recording_pd == NULL && recording->recording_pdumper == NULL) {
-		int rand_bytes = 16;
-		int rec_path_len = strlen(spooldir) + 8; // spool directory path + "/pcaps/"
+		int rand_bytes = 8;
+		// Length for spool directory path + "/pcaps/${CALLID}-"
+		int rec_path_len = strlen(spooldir) + 7 + callid.len + 1 + 1;
 		char rec_path[rec_path_len];
-		snprintf(rec_path, rec_path_len, "%s/pcaps/", spooldir);
-		char *path_chars = rand_affixed_str(rand_bytes, rec_path, ".pcap");
+		snprintf(rec_path, rec_path_len, "%s/pcaps/%s-", spooldir, callid.s);
+		char *path_chars = rand_affixed_str(rec_path, rand_bytes, ".pcap");
 
 		recording_path = malloc(sizeof(str));
 		recording_path = str_init(recording_path, path_chars);

daemon/recording.h

@@ -44,20 +44,29 @@ void recording_fs_init(char *spooldir);
  *
  *     generic metadata
  *
+ * Temporary files go in /tmp/. They will end up in
+ * ${RECORDING_DIR}/metadata/. They are named like:
+ * ${CALL_ID}-${RAND-HEX}.pcap
+ *
  */
-str *meta_setup_file(struct recording *recording);
+str *meta_setup_file(struct recording *recording, str callid);
 
 /**
- * Writes metadata to metafile, closes file, and renames it to finished location.
+ * Writes metadata to metafile, closes file, and moves it to finished location.
  * Returns non-zero for failure.
+ *
+ * Metadata files are moved to ${RECORDING_DIR}/metadata/
  */
 int meta_finish_file(struct call *call);
 
 /**
  * Generate a random PCAP filepath to write recorded RTP stream.
  * Returns path to created file.
+ *
+ * Files go in ${RECORDING_DIR}/pcaps, and are named like:
+ * ${CALL_ID}-${RAND-HEX}.pcap
  */
-str *recording_setup_file(struct recording *recording);
+str *recording_setup_file(struct recording *recording, str callid);
 
 /**
  * Flushes PCAP file, closes the dumper and descriptors, and frees object memory.

daemon/str.c

@@ -41,13 +41,13 @@ void str_slice_free(void *p) {
  */
 char *rand_affixed_str(int num_bytes, char *prefix, char *suffix) {
 	int rand_len = num_bytes*2 + 1;
-	char rand_prefix[rand_len];
+	char rand_affix[rand_len];
 	int prefix_len = strlen(prefix);
 	int suffix_len = strlen(suffix);
 	char *full_path = calloc(rand_len + prefix_len + suffix_len, sizeof(char));
 
-	rand_hex_str(rand_prefix, num_bytes);
-	snprintf(full_path, rand_len+prefix_len, "%s%s", prefix, rand_prefix);
+	rand_hex_str(rand_affix, num_bytes);
+	snprintf(full_path, rand_len+prefix_len, "%s%s", prefix, rand_affix);
 	snprintf(full_path + rand_len+prefix_len-1, suffix_len+1, "%s", suffix);
 	return full_path;
 }

daemon/str.h

@@ -294,7 +294,7 @@ INLINE int str_token(str *new_token, str *ori_and_remainder, int sep) {
 
 
 /* Generates a random string sandwiched between affixes. */
-char *rand_affixed_str(int num_bytes, char *prefix, char *suffix);
+char *rand_affixed_str(char *prefix, int num_bytes, char *suffix);
 /* Generates a hex string representing n random bytes. len(rand_str) = 2*num_bytes + 1 */
 char *rand_hex_str(char *rand_str, int num_bytes);