X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=dccp_send.c;h=7d8967cca6f9ad47dc5b8578b350fd81d2ad49d8;hp=d2f81dd9168023df27a1fefdb883e3234382c1cc;hb=85d8b1b48ef832eaf485709f38cb443e5ecfbb7b;hpb=ec354cf583bc2838ecfac64c428d3f992681c5fc

diff --git a/dccp_send.c b/dccp_send.c
index d2f81dd9..7d8967cc 100644
--- a/dccp_send.c
+++ b/dccp_send.c
@@ -44,15 +44,46 @@ static void dccp_pre_select(int *max_fileno, fd_set *rfds,
 		para_fd_set(dss->listen_fd, rfds, max_fileno);
 }
 
+/**
+ * Query the TX CCID used on the sender-client half connection.
+ * \param sockfd Server socket descriptor to query (after accept(2)).
+ * \return CCID number > 0, -1 on error/incompatibility.
+ *
+ * NB: This feature is only available on Linux > 2.6.30; on older kernels
+ * ENOPROTOOPT ("Protocol not available") will be returned.
+ */
+static int dccp_get_tx_ccid(int sockfd)
+{
+	int tx_ccid;
+	socklen_t len = sizeof(tx_ccid);
+
+	if (getsockopt(sockfd, SOL_DCCP,
+		       DCCP_SOCKOPT_TX_CCID, &tx_ccid, &len) < 0) {
+		PARA_WARNING_LOG("DCCP_SOCKOPT_TX_CCID: %s\n", strerror(errno));
+		return -1;
+	}
+	return tx_ccid;
+}
+
 static void dccp_post_select(fd_set *rfds, __a_unused fd_set *wfds)
 {
 	struct sender_client *sc;
+	int tx_ccid;
 
 	if (dss->listen_fd < 0 || !FD_ISSET(dss->listen_fd, rfds))
 		return;
 	sc = accept_sender_client(dss);
 	if (!sc)
 		return;
+
+	/* If CCID identifiable, present client as <host>#<port>~<ccid> */
+	tx_ccid = dccp_get_tx_ccid(sc->fd);
+	if (tx_ccid != -1) {
+		char *tmp = make_message("%s~%d", sc->name, tx_ccid);
+
+		free(sc->name);
+		sc->name = tmp;
+	}
 	/*
 	 * Bypass unused CCID paths: the sender does not receive application data
 	 * from the client; by shutting down this unused communication path we can
@@ -104,9 +135,33 @@ static int dccp_com_allow(struct sender_command_data *scd)
 	return 1;
 }
 
+/**
+ * Return list of available CCIDs or warning, in static buffer.
+ */
+static const char *dccp_list_available_ccids(void)
+{
+	uint8_t ccids[DCCP_MAX_HOST_CCIDS];
+	uint8_t nccids = sizeof(ccids), i, len;
+	/* Worst case length: n * 3 digits + n-1 spaces + '\0' */
+	static char list[DCCP_MAX_HOST_CCIDS * 4];
+
+	if (dccp_available_ccids(ccids, &nccids) == NULL) {
+		snprintf(list, sizeof(list), "Unable to query available CCIDs");
+	} else {
+		for (i = len = 0; i < nccids; i++)
+			len += snprintf(list + len, sizeof(list) - len,
+					"%s%d", i ? " " : "", ccids[i]);
+	}
+	return list;
+}
+
 static char *dccp_info(void)
 {
-	return get_sender_info(dss, "dccp");
+	char *info = get_sender_info(dss, "dccp");
+	char *ret  = make_message("%s" "\tsupported ccids: %s\n",
+				  info, dccp_list_available_ccids());
+	free(info);
+	return ret;
 }
 
 /**