af-packet: add support for checksum verif mode

This patch adds support for checksum verification mode.
Auto mode is not yet supported.

src/runmode-af-packet.c

@@ -125,7 +125,7 @@ void *ParseAFPConfig(const char *iface)
     aconf->cluster_id = 1;
     aconf->cluster_type = PACKET_FANOUT_HASH;
     aconf->promisc = 1;
-    aconf->detect_offload = 1;
+    aconf->checksum_mode = CHECKSUM_VALIDATION_KERNEL;
     aconf->DerefFunc = AFPDerefConfig;
 
     /* Find initial node */
@@ -204,14 +204,25 @@ void *ParseAFPConfig(const char *iface)
                 aconf->iface);
         aconf->promisc = 0;
     }
-    ConfGetChildValueBool(if_root, "detect-offload", (int *)&boolval);
-    if (! boolval) {
-        SCLogInfo("Disabling checksum offloading detection for %s",
-                aconf->iface);
-        aconf->detect_offload = 0;
-    }
-
 
+    if (ConfGetChildValue(if_root, "checksum-checks", &tmpctype) != 1) {
+        SCLogError(SC_ERR_INVALID_ARGUMENT, "Could not get checksum-checks from config");
+    } else {
+        if (strcmp(tmpctype, "auto") == 0) {
+            SCLogError(SC_ERR_INVALID_ARGUMENT,"'auto' mode is currently not supported");
+            /*
+            aconf->checksum_mode = CHECKSUM_VALIDATION_AUTO;
+            */
+        } else if (strcmp(tmpctype, "yes") == 0) {
+            aconf->checksum_mode = CHECKSUM_VALIDATION_ENABLE;
+        } else if (strcmp(tmpctype, "no") == 0) {
+            aconf->checksum_mode = CHECKSUM_VALIDATION_DISABLE;
+        } else if (strcmp(tmpctype, "kernel") == 0) {
+            aconf->checksum_mode = CHECKSUM_VALIDATION_KERNEL;
+        } else {
+            SCLogError(SC_ERR_INVALID_ARGUMENT, "Invalid value for checksum-checks for %s", aconf->iface);
+        }
+    }
 
     return aconf;
 }

src/source-af-packet.c

@@ -160,14 +160,13 @@ typedef struct AFPThreadVars_
     /* socket buffer size */
     int buffer_size;
     int promisc;
-    int detect_offload;
+    ChecksumValidationMode checksum_mode;
 
     int cluster_id;
     int cluster_type;
 
     int threads;
 
-
 } AFPThreadVars;
 
 TmEcode ReceiveAFP(ThreadVars *, Packet *, void *, PacketQueue *, PacketQueue *);
@@ -290,21 +289,29 @@ int AFPRead(AFPThreadVars *ptv)
     SCLogDebug("pktlen: %" PRIu32 " (pkt %p, pkt data %p)",
                GET_PKT_LEN(p), p, GET_PKT_DATA(p));
 
-    for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
-        struct tpacket_auxdata *aux;
-
-        if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct tpacket_auxdata)) ||
-                cmsg->cmsg_level != SOL_PACKET ||
-                cmsg->cmsg_type != PACKET_AUXDATA)
-            continue;
+    /* We only check for checksum disable */
+    if (ptv->checksum_mode == CHECKSUM_VALIDATION_DISABLE) {
+            p->flags |= PKT_IGNORE_CHECKSUM;
+    } else {
+        /* List is NULL if we don't have activated auxiliary data */
+        for (cmsg = CMSG_FIRSTHDR(&msg); cmsg; cmsg = CMSG_NXTHDR(&msg, cmsg)) {
+            struct tpacket_auxdata *aux;
+
+            if (cmsg->cmsg_len < CMSG_LEN(sizeof(struct tpacket_auxdata)) ||
+                    cmsg->cmsg_level != SOL_PACKET ||
+                    cmsg->cmsg_type != PACKET_AUXDATA)
+                continue;
 
-        aux = (struct tpacket_auxdata *)CMSG_DATA(cmsg);
+            aux = (struct tpacket_auxdata *)CMSG_DATA(cmsg);
 
-        if (aux->tp_status & TP_STATUS_CSUMNOTREADY) {
-            p->flags |= PKT_IGNORE_CHECKSUM;
+            if (aux->tp_status & TP_STATUS_CSUMNOTREADY) {
+                p->flags |= PKT_IGNORE_CHECKSUM;
+            }
+            break;
         }
     }
 
+
     if (TmThreadsSlotProcessPkt(ptv->tv, ptv->slot, p) != TM_ECODE_OK) {
         TmqhOutputPacketpool(ptv->tv, p);
         SCReturnInt(AFP_FAILURE);
@@ -523,7 +530,7 @@ static int AFPCreateSocket(AFPThreadVars *ptv, char *devname, int verbose)
         }
     }
 
-    if (ptv->detect_offload) {
+    if (ptv->checksum_mode == CHECKSUM_VALIDATION_KERNEL) {
         int    val = 1;
         if (setsockopt(ptv->socket, SOL_PACKET, PACKET_AUXDATA, &val,
                     sizeof(val)) == -1 && errno != ENOPROTOOPT) {
@@ -613,7 +620,7 @@ TmEcode ReceiveAFPThreadInit(ThreadVars *tv, void *initdata, void **data) {
     ptv->buffer_size = afpconfig->buffer_size;
 
     ptv->promisc = afpconfig->promisc;
-    ptv->detect_offload = afpconfig->detect_offload;
+    ptv->checksum_mode = afpconfig->checksum_mode;
 
     ptv->threads = 1;
 #ifdef HAVE_PACKET_FANOUT

src/source-af-packet.h

@@ -53,8 +53,7 @@ typedef struct AFPIfaceConfig_
     int cluster_type;
     /* promisc mode */
     int promisc;
-    /* no local packet */
-    int detect_offload;
+    ChecksumValidationMode checksum_mode;
     SC_ATOMIC_DECLARE(unsigned int, ref);
     void (*DerefFunc)(void *);
 } AFPIfaceConfig;