Add and use utility functions for checksum computing.

src/Makefile.am

@@ -210,6 +210,7 @@ util-proto-name.c util-proto-name.h \
 util-syslog.c util-syslog.h \
 util-vector.h \
 util-device.c util-device.h \
+util-checksum.c util-checksum.h \
 tm-modules.c tm-modules.h \
 tm-queues.c tm-queues.h \
 tm-queuehandlers.c tm-queuehandlers.h \

src/detect-replace.c

@@ -45,6 +45,9 @@ extern int run_mode;
 #include "detect-engine-mpm.h"
 #include "detect-engine.h"
 #include "detect-engine-state.h"
+
+#include "util-checksum.h"
+
 #include "util-unittest.h"
 #include "util-unittest-helper.h"
 
@@ -176,33 +179,7 @@ void DetectReplaceExecute(Packet *p, DetectReplaceList *replist)
         memcpy(replist->found, replist->cd->replace, replist->cd->replace_len);
         SCLogDebug("replace: injecting '%s'", replist->cd->replace);
         p->flags |= PKT_STREAM_MODIFIED;
-        if (PKT_IS_IPV4(p)) {
-            if (PKT_IS_TCP(p)) {
-                /* TCP */
-                p->tcph->th_sum = 0;
-                p->tcph->th_sum = TCPCalculateChecksum((uint16_t *)&(p->ip4h->ip_src),
-                        (uint16_t *)p->tcph, (p->payload_len + TCP_GET_HLEN(p)));
-            } else if (PKT_IS_UDP(p)) {
-                p->udph->uh_sum = 0;
-                p->udph->uh_sum = UDPV4CalculateChecksum((uint16_t *)&(p->ip4h->ip_src),
-                        (uint16_t *)p->udph, (p->payload_len + UDP_HEADER_LEN));
-            }
-            /* IPV4 */
-            p->ip4h->ip_csum = 0;
-            p->ip4h->ip_csum = IPV4CalculateChecksum((uint16_t *)p->ip4h,
-                    IPV4_GET_RAW_HLEN(p->ip4h));
-        } else if (PKT_IS_IPV6(p)) {
-            /* just TCP for IPV6 */
-            if (PKT_IS_TCP(p)) {
-                p->tcph->th_sum = 0;
-                p->tcph->th_sum = TCPV6CalculateChecksum((uint16_t *)&(p->ip6h->ip6_src),
-                        (uint16_t *)p->tcph, (p->payload_len + TCP_GET_HLEN(p)));
-            } else if (PKT_IS_UDP(p)) {
-                p->udph->uh_sum = 0;
-                p->udph->uh_sum = UDPV6CalculateChecksum((uint16_t *)&(p->ip6h->ip6_src),
-                        (uint16_t *)p->udph, (p->payload_len + UDP_HEADER_LEN));
-            }
-        }
+        ReCalculateChecksum(p);
         tlist = replist;
         replist = replist->next;
         SCFree(tlist);

src/stream-tcp-inline.c

@@ -180,39 +180,6 @@ void StreamTcpInlineSegmentReplacePacket(Packet *p, TcpSegment *seg) {
     }
 }
 
-/**
- *  \brief Recalculate the csum for a modified packet
- *
- *  \param p packet to inspect
- */
-void StreamTcpInlineRecalcCsum(Packet *p) {
-    if (!(p->flags & PKT_STREAM_MODIFIED)) {
-        SCReturn;
-    }
-
-    if (!(PKT_IS_TCP(p))) {
-        SCReturn;
-    }
-
-    if (PKT_IS_IPV4(p)) {
-        /* TCP */
-        p->tcph->th_sum = 0;
-        p->tcph->th_sum = TCPCalculateChecksum((uint16_t *)&(p->ip4h->ip_src),
-                (uint16_t *)p->tcph, (p->payload_len + TCP_GET_HLEN(p)));
-        /* IPV4 */
-        p->ip4h->ip_csum = 0;
-        p->ip4h->ip_csum = IPV4CalculateChecksum((uint16_t *)p->ip4h,
-                IPV4_GET_RAW_HLEN(p->ip4h));
-    } else if (PKT_IS_IPV6(p)) {
-        /* just TCP for IPV6 */
-        p->tcph->th_sum = 0;
-        p->tcph->th_sum = TCPV6CalculateChecksum((uint16_t *)&(p->ip6h->ip6_src),
-                (uint16_t *)p->tcph, (p->payload_len + TCP_GET_HLEN(p)));
-    }
-
-    SCReturn;
-}
-
 #ifdef UNITTESTS
 
 /** \test full overlap */

src/stream-tcp-inline.h

@@ -29,7 +29,6 @@
 int StreamTcpInlineMode(void);
 int StreamTcpInlineSegmentCompare(TcpSegment *, TcpSegment *);
 void StreamTcpInlineSegmentReplacePacket(Packet *, TcpSegment *);
-void StreamTcpInlineRecalcCsum(Packet *);
 
 void StreamTcpInlineRegisterTests(void);
 

src/stream-tcp.c

@@ -44,6 +44,7 @@
 #include "tm-threads.h"
 
 #include "util-pool.h"
+#include "util-checksum.h"
 #include "util-unittest.h"
 #include "util-print.h"
 #include "util-debug.h"
@@ -3653,7 +3654,7 @@ static int StreamTcpPacket (ThreadVars *tv, Packet *p, StreamTcpThread *stt,
 
     /* recalc the csum on the packet if it was modified */
     if (p->flags & PKT_STREAM_MODIFIED) {
-        StreamTcpInlineRecalcCsum(p);
+        ReCalculateChecksum(p);
     }
 
     /* check for conditions that may make us not want to log this packet */
@@ -3686,7 +3687,7 @@ error:
 
     /* recalc the csum on the packet if it was modified */
     if (p->flags & PKT_STREAM_MODIFIED) {
-        StreamTcpInlineRecalcCsum(p);
+        ReCalculateChecksum(p);
     }
 
     if (StreamTcpInlineMode()) {

src/util-checksum.c

@@ -0,0 +1,59 @@
+/* Copyright (C) 2011 Open Information Security Foundation
+ *
+ * You can copy, redistribute or modify this Program under the terms of
+ * the GNU General Public License version 2 as published by the Free
+ * Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+/**
+ * \file
+ *
+ * \author Eric Leblond <eric@regit.org>
+ *
+ * Util functions for checskum.
+ */
+
+#include "suricata-common.h"
+
+int ReCalculateChecksum(Packet *p)
+{
+    if (PKT_IS_IPV4(p)) {
+        if (PKT_IS_TCP(p)) {
+            /* TCP */
+            p->tcph->th_sum = 0;
+            p->tcph->th_sum = TCPCalculateChecksum((uint16_t *)&(p->ip4h->ip_src),
+                    (uint16_t *)p->tcph, (p->payload_len + TCP_GET_HLEN(p)));
+        } else if (PKT_IS_UDP(p)) {
+            p->udph->uh_sum = 0;
+            p->udph->uh_sum = UDPV4CalculateChecksum((uint16_t *)&(p->ip4h->ip_src),
+                    (uint16_t *)p->udph, (p->payload_len + UDP_HEADER_LEN));
+        }
+        /* IPV4 */
+        p->ip4h->ip_csum = 0;
+        p->ip4h->ip_csum = IPV4CalculateChecksum((uint16_t *)p->ip4h,
+                IPV4_GET_RAW_HLEN(p->ip4h));
+    } else if (PKT_IS_IPV6(p)) {
+        /* just TCP for IPV6 */
+        if (PKT_IS_TCP(p)) {
+            p->tcph->th_sum = 0;
+            p->tcph->th_sum = TCPV6CalculateChecksum((uint16_t *)&(p->ip6h->ip6_src),
+                    (uint16_t *)p->tcph, (p->payload_len + TCP_GET_HLEN(p)));
+        } else if (PKT_IS_UDP(p)) {
+            p->udph->uh_sum = 0;
+            p->udph->uh_sum = UDPV6CalculateChecksum((uint16_t *)&(p->ip6h->ip6_src),
+                    (uint16_t *)p->udph, (p->payload_len + UDP_HEADER_LEN));
+        }
+    }
+
+    return 0;
+}

src/util-checksum.h

@@ -0,0 +1,30 @@
+/* Copyright (C) 2011 Open Information Security Foundation
+ *
+ * You can copy, redistribute or modify this Program under the terms of
+ * the GNU General Public License version 2 as published by the Free
+ * Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * version 2 along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+/**
+ * \file
+ *
+ * \author Eric Leblond <eric@regit.org>
+ */
+
+#ifndef __UTIL_CHECKSUM_H__
+#define __UTIL_CHECKSUM_H__
+
+
+int ReCalculateChecksum(Packet *p);
+
+#endif