Changeset e68325b for lib

Timestamp:

11/07/17 17:16:31 (3 years ago)

Author:

Shane Alcock <salcock@…>

Branches:

cachetimestamps, develop, dpdk-ndag, etsilive, master, ndag_format, rc-4.0.2, rc-4.0.3, rc-4.0.4, ringdecrementfix, ringperformance

Children:

05b65ae

Parents:

de825b5

Message:

Add support for receiving keep-alives on the ndag sockets.

These are used by the ndag transmitter to let clients know that
they haven't died; instead, there have been no packets to export
for some reason.

Location:

lib

Files:

• format_ndag.c (modified) (4 diffs)
• format_ndag.h (modified) (1 diff)

lib/format_ndag.c

@@ -717 +717 @@
         int i, ret, readybufs, gottime;
         struct timeval tv;
+        uint8_t rectype;
 
         readybufs = 0;
@@ -773 +774 @@
 
                 /* Check that we have a valid nDAG encap record */
-                if (check_ndag_header(rt->sources[i].saved[nw], ret) !=
-                                        NDAG_PKT_ENCAPERF) {
+                rectype = check_ndag_header(rt->sources[i].saved[nw], ret);
+
+                if (rectype == NDAG_PKT_KEEPALIVE) {
+                        /* Keep-alive, reset startidle and carry on. Don't
+                         * change nextwrite -- we want to overwrite the
+                         * keep-alive with usable content. */
+                        continue;
+                } else if (rectype != NDAG_PKT_ENCAPERF) {
                         fprintf(stderr, "Received invalid record on the channel for %s:%u.\n",
                                         rt->sources[i].groupaddr,
@@ -787 +794 @@
                                 (rt->sources[i].nextwriteind + 1) % ENCAP_BUFFERS;
 
-                /* Save the useful info from the encap header */
+                /* Get the useful info from the encap header */
                 encaphdr = (ndag_encap_t *)(rt->sources[i].saved[nw] +
                                 sizeof(ndag_common_t));
@@ -798 +805 @@
                 rt->sources[i].expectedseq = ntohl(encaphdr->seqno) + 1;
 
-                /* If all good, skip past the nDAG headers */
                 if (rt->sources[i].nextread == NULL) {
+                        /* If this is our first read, set up 'nextread'
+                         * by skipping past the nDAG headers */
                         rt->sources[i].nextread = rt->sources[i].saved[0] +
                                         sizeof(ndag_common_t) + sizeof(ndag_encap_t);

lib/format_ndag.h

@@ -15 +15 @@
         NDAG_PKT_RESTARTED = 0x03,
         NDAG_PKT_ENCAPRT = 0x04,
+        NDAG_PKT_KEEPALIVE = 0x05
 };