af-packet: fix reconnection on netdown error.

AFPRead can fail following a NETDOWN error. This patch treat errors
of AFPRead by forcing a reconnection (instead of exiting thread
with error).

src/source-af-packet.c

@@ -125,6 +125,12 @@ TmEcode NoAFPSupportExit(ThreadVars *tv, void *initdata, void **data)
 
 #define POLL_TIMEOUT 100
 
+enum {
+    AFP_READ_OK,
+    AFP_READ_FAILURE,
+    AFP_FAILURE,
+};
+
 /**
  * \brief Structure to hold thread specific variables.
  */
@@ -213,7 +219,7 @@ static int AFPCreateSocket(AFPThreadVars *ptv, char *devname, int verbose);
  * \param user pointer to AFPThreadVars
  * \retval TM_ECODE_FAILED on failure and TM_ECODE_OK on success
  */
-TmEcode AFPRead(AFPThreadVars *ptv)
+int AFPRead(AFPThreadVars *ptv)
 {
     Packet *p = NULL;
     /* XXX should try to use read that get directly to packet */
@@ -252,12 +258,12 @@ TmEcode AFPRead(AFPThreadVars *ptv)
     if (caplen < 0) {
         SCLogWarning(SC_ERR_AFP_READ, "recvmsg failed with error code %" PRId32,
                 errno);
-        SCReturnInt(TM_ECODE_FAILED);
+        SCReturnInt(AFP_READ_FAILURE);
     }
 
     p = PacketGetFromQueueOrAlloc();
     if (p == NULL) {
-        SCReturnInt(TM_ECODE_FAILED);
+        SCReturnInt(AFP_FAILURE);
     }
 
     /* get timestamp of packet via ioctl */
@@ -265,7 +271,7 @@ TmEcode AFPRead(AFPThreadVars *ptv)
         SCLogWarning(SC_ERR_AFP_READ, "recvmsg failed with error code %" PRId32,
                 errno);
         TmqhOutputPacketpool(ptv->tv, p);
-        SCReturnInt(TM_ECODE_FAILED);
+        SCReturnInt(AFP_READ_FAILURE);
     }
 
     ptv->pkts++;
@@ -282,16 +288,16 @@ TmEcode AFPRead(AFPThreadVars *ptv)
     SET_PKT_LEN(p, caplen + offset);
     if (PacketCopyData(p, ptv->data, GET_PKT_LEN(p)) == -1) {
         TmqhOutputPacketpool(ptv->tv, p);
-        SCReturnInt(TM_ECODE_FAILED);
+        SCReturnInt(AFP_FAILURE);
     }
     SCLogDebug("pktlen: %" PRIu32 " (pkt %p, pkt data %p)",
                GET_PKT_LEN(p), p, GET_PKT_DATA(p));
 
     if (TmThreadsSlotProcessPkt(ptv->tv, ptv->slot, p) != TM_ECODE_OK) {
         TmqhOutputPacketpool(ptv->tv, p);
-        SCReturnInt(TM_ECODE_FAILED);
+        SCReturnInt(AFP_FAILURE);
     }
-    SCReturnInt(TM_ECODE_OK);
+    SCReturnInt(AFP_READ_OK);
 }
 
 static int AFPTryReopen(AFPThreadVars *ptv)
@@ -383,8 +389,19 @@ TmEcode ReceiveAFPLoop(ThreadVars *tv, void *data, void *slot)
         } else if (r > 0) {
             /* AFPRead will call TmThreadsSlotProcessPkt on read packets */
             r = AFPRead(ptv);
-            if (r != TM_ECODE_OK) {
-                SCReturnInt(TM_ECODE_FAILED);
+            switch (r) {
+                case AFP_READ_FAILURE:
+                    /* AFPRead in error: best to reset the socket */
+                    SCLogError(SC_ERR_AFP_READ, "AFPRead error reading data from socket: (%d" PRIu32 ") %s",
+                            errno, strerror(errno));
+                    close(ptv->socket);
+                    ptv->afp_state = AFP_STATE_DOWN;
+                    continue;
+                case AFP_FAILURE:
+                    SCReturnInt(TM_ECODE_FAILED);
+                    break;
+                case AFP_READ_OK:
+                    break;
             }
         } else if ((r < 0) && (errno != EINTR)) {
             SCLogError(SC_ERR_AFP_READ, "Error reading data from socket: (%d" PRIu32 ") %s",