[Oisf-devel] [PATCHv2 1/2] Add support for 'nfq_set_mark' keyword

Eric Leblond eric at regit.org
Thu Mar 10 22:04:23 UTC 2011


This patch introduces 'nfq_set_mark' which is new rules option. If a packet
matches a rule using nfq_set_mark in NFQ mode, it is marked with the mark/mask
specified in the option during the verdict.
It is thus possible to trigger different behaviour on the packet inside
Linux/Netfilter.
---
 src/Makefile.am   |    1 +
 src/decode.h      |    1 +
 src/detect-mark.c |  341 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/detect-mark.h |   61 ++++++++++
 src/detect.c      |    1 +
 src/detect.h      |    2 +
 6 files changed, 407 insertions(+), 0 deletions(-)
 create mode 100644 src/detect-mark.c
 create mode 100644 src/detect-mark.h

diff --git a/src/Makefile.am b/src/Makefile.am
index dd0392e..66c1864 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -111,6 +111,7 @@ detect-flags.c detect-flags.h \
 detect-fragbits.c detect-fragbits.h \
 detect-fragoffset.c detect-fragoffset.h \
 detect-gid.c detect-gid.h \
+detect-mark.c detect-mark.h \
 detect-noalert.c detect-noalert.h \
 detect-csum.c detect-csum.h \
 detect-ttl.c detect-ttl.h \
diff --git a/src/decode.h b/src/decode.h
index 4b75920..f8cbc3a 100644
--- a/src/decode.h
+++ b/src/decode.h
@@ -813,6 +813,7 @@ void AddressDebugPrint(Address *);
 #define PKT_HAS_FLOW                    0x0080
 #define PKT_PSEUDO_STREAM_END           0x0100    /**< Pseudo packet to end the stream */
 #define PKT_STREAM_MODIFIED             0x0200    /**< Packet is modified by the stream engine, we need to recalc the csum and reinject/replace */
+#define PKT_MARK_MODIFIED               0x0400    /**< Packet mark is modified */
 
 /** \brief return 1 if the packet is a pseudo packet */
 #define PKT_IS_PSEUDOPKT(p) ((p)->flags & PKT_PSEUDO_STREAM_END)
diff --git a/src/detect-mark.c b/src/detect-mark.c
new file mode 100644
index 0000000..eab4595
--- /dev/null
+++ b/src/detect-mark.c
@@ -0,0 +1,341 @@
+/* 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 at regit.org>
+ *
+ * Implements the mark keyword. Based  on detect-gid
+ * by Breno Silva <breno.silva at gmail.com>
+ */
+
+#include "suricata-common.h"
+#include "suricata.h"
+#include "decode.h"
+#include "detect.h"
+#include "flow-var.h"
+#include "decode-events.h"
+
+#include "detect-mark.h"
+#include "detect-parse.h"
+
+#include "util-unittest.h"
+#include "util-debug.h"
+
+#define PARSE_REGEX "([0x]*[0-9a-f]+)/([0x]*[0-9a-f]+)"
+
+static pcre *parse_regex;
+static pcre_extra *parse_regex_study;
+
+static int DetectMarkSetup (DetectEngineCtx *, Signature *, char *);
+int DetectMarkPacket(ThreadVars *t, DetectEngineThreadCtx *det_ctx, Packet *p, Signature *s, SigMatch *m);
+void DetectMarkDataFree(void *ptr);
+
+/**
+ * \brief Registration function for nfq_set_mark: keyword
+ */
+
+void DetectMarkRegister (void) {
+    sigmatch_table[DETECT_MARK].name = "nfq_set_mark";
+    sigmatch_table[DETECT_MARK].Match = DetectMarkPacket;
+    sigmatch_table[DETECT_MARK].Setup = DetectMarkSetup;
+    sigmatch_table[DETECT_MARK].Free  = DetectMarkDataFree;
+    sigmatch_table[DETECT_MARK].RegisterTests = MarkRegisterTests;
+
+    const char *eb;
+    int opts = 0;
+    int eo;
+
+    parse_regex = pcre_compile(PARSE_REGEX, opts, &eb, &eo, NULL);
+    if(parse_regex == NULL)
+    {
+        SCLogError(SC_ERR_PCRE_COMPILE, "pcre compile of \"%s\" failed at offset %" PRId32 ": %s", PARSE_REGEX, eo, eb);
+        goto error;
+    }
+
+    parse_regex_study = pcre_study(parse_regex, 0, &eb);
+    if(eb != NULL)
+    {
+        SCLogError(SC_ERR_PCRE_STUDY, "pcre study failed: %s", eb);
+        goto error;
+    }
+
+error:
+    return;
+
+}
+
+#ifdef NFQ
+/**
+ * \internal
+ * \brief This function is used to parse mark options passed via mark: keyword
+ *
+ * \param rawstr Pointer to the user provided mark options
+ *
+ * \retval 0 on success
+ * \retval < 0 on failure
+ */
+static void * DetectMarkParse (char *rawstr)
+{
+    int ret = 0, res = 0;
+#define MAX_SUBSTRINGS 30
+    int ov[MAX_SUBSTRINGS];
+    const char *str_ptr = NULL;
+    char *ptr = NULL;
+    char *endptr = NULL;
+    uint32_t mark;
+    uint32_t mask;
+    DetectMarkData *data;
+
+    ret = pcre_exec(parse_regex, parse_regex_study, rawstr, strlen(rawstr), 0, 0, ov, MAX_SUBSTRINGS);
+    if (ret < 1) {
+        SCLogError(SC_ERR_PCRE_MATCH, "pcre_exec parse error, ret %" PRId32 ", string %s", ret, rawstr);
+        return NULL;
+    }
+
+    res = pcre_get_substring((char *)rawstr, ov, MAX_SUBSTRINGS, 1, &str_ptr);
+    if (res < 0) {
+        SCLogError(SC_ERR_PCRE_GET_SUBSTRING, "pcre_get_substring failed");
+        return NULL;
+    }
+
+    ptr = (char *)str_ptr;
+
+    if (ptr == NULL)
+        return NULL;
+
+    errno = 0;
+    mark = strtoul(ptr, &endptr, 0);
+    if (errno == ERANGE) {
+        SCLogError(SC_ERR_NUMERIC_VALUE_ERANGE, "Numeric value out of range");
+        SCFree(ptr);
+        return NULL;
+    }     /* If there is no numeric value in the given string then strtoull(), makes
+             endptr equals to ptr and return 0 as result */
+    else if (endptr == ptr && mark == 0) {
+        SCLogError(SC_ERR_INVALID_NUMERIC_VALUE, "No numeric value");
+        SCFree(ptr);
+        return NULL;
+    } else if (endptr == ptr) {
+        SCLogError(SC_ERR_INVALID_NUMERIC_VALUE, "Invalid numeric value");
+        SCFree(ptr);
+        return NULL;
+    }
+
+    res = pcre_get_substring((char *)rawstr, ov, MAX_SUBSTRINGS, 2, &str_ptr);
+    if (res < 0) {
+        SCLogError(SC_ERR_PCRE_GET_SUBSTRING, "pcre_get_substring failed");
+        return NULL;
+    }
+
+    SCFree(ptr);
+    ptr = (char *)str_ptr;
+
+    if (ptr == NULL) {
+        data = SCMalloc(sizeof(DetectMarkData));
+        data->mark = mark;
+        data->mask = 0xffff;
+        return data;
+    }
+
+    errno = 0;
+    mask = strtoul(ptr, &endptr, 0);
+    if (errno == ERANGE) {
+        SCLogError(SC_ERR_NUMERIC_VALUE_ERANGE, "Numeric value out of range");
+        SCFree(ptr);
+        return NULL;
+    }     /* If there is no numeric value in the given string then strtoull(), makes
+             endptr equals to ptr and return 0 as result */
+    else if (endptr == ptr && mask == 0) {
+        SCLogError(SC_ERR_INVALID_NUMERIC_VALUE, "No numeric value");
+        SCFree(ptr);
+        return NULL;
+    }
+    else if (endptr == ptr) {
+        SCLogError(SC_ERR_INVALID_NUMERIC_VALUE, "Invalid numeric value");
+        SCFree(ptr);
+        return NULL;
+    }
+
+    SCLogDebug("Rule will set mark 0x%x with mask 0x%x", mark, mask);
+    SCFree(ptr);
+
+    data = SCMalloc(sizeof(DetectMarkData));
+    data->mark = mark;
+    data->mask = mask;
+    return data;
+}
+
+#endif /* NFQ */
+
+/**
+ * \internal
+ * \brief this function is used to add the parsed mark into the current signature
+ *
+ * \param de_ctx pointer to the Detection Engine Context
+ * \param s pointer to the Current Signature
+ * \param rawstr pointer to the user provided mark options
+ *
+ * \retval 0 on Success
+ * \retval -1 on Failure
+ */
+static int DetectMarkSetup (DetectEngineCtx *de_ctx, Signature *s, char *rawstr)
+{
+#ifdef NFQ
+    DetectMarkData *data = NULL;
+    SigMatch *sm = NULL;
+
+    data = DetectMarkParse(rawstr);
+
+    if (data == NULL) {
+        return -1;
+    } else {
+        sm = SigMatchAlloc();
+        if (sm == NULL) {
+            DetectMarkDataFree(data);
+            return -1;
+        }
+
+        sm->type = DETECT_MARK;
+        sm->ctx = (void *)data;
+
+        /* Append it to the list of tags */
+        SigMatchAppendTag(s, sm);
+        return 0;
+    }
+#else
+    return 0;
+#endif
+}
+
+void DetectMarkDataFree(void *ptr)
+{
+    DetectMarkData *data = (DetectMarkData *)ptr;
+    SCFree(data);
+}
+
+
+int DetectMarkPacket(ThreadVars *t, DetectEngineThreadCtx *det_ctx, Packet *p, Signature *s, SigMatch *m)
+{
+    DetectMarkData *nf_data = (DetectMarkData *) m->ctx;
+#ifdef NFQ
+    if (nf_data->mask) {
+        p->nfq_v.mark = (nf_data->mark & nf_data->mask)
+                        | (p->nfq_v.mark & ~(nf_data->mask));
+        p->flags |= PKT_MARK_MODIFIED;
+    }
+#endif
+    return 0;
+}
+
+/*
+ * ONLY TESTS BELOW THIS COMMENT
+ */
+
+#if defined UNITTESTS && defined NFQ
+/**
+ * \test MarkTestParse01 is a test for a valid mark value
+ *
+ *  \retval 1 on succces
+ *  \retval 0 on failure
+ */
+static int MarkTestParse01 (void) {
+    DetectMarkData *data;
+
+    data = DetectMarkParse("1/1");
+
+    if (data == NULL) {
+        return 0;
+    }
+
+    DetectMarkDataFree(data);
+    return 1;
+}
+
+/**
+ * \test MarkTestParse02 is a test for an invalid mark value
+ *
+ *  \retval 1 on succces
+ *  \retval 0 on failure
+ */
+static int MarkTestParse02 (void) {
+    DetectMarkData *data;
+
+    data = DetectMarkParse("4");
+
+    if (data == NULL) {
+        return 0;
+    }
+
+    DetectMarkDataFree(data);
+    return 1;
+}
+
+/**
+ * \test MarkTestParse03 is a test for a valid mark value
+ *
+ *  \retval 1 on succces
+ *  \retval 0 on failure
+ */
+static int MarkTestParse03 (void) {
+    DetectMarkData *data;
+
+    data = DetectMarkParse("0x10/0xff");
+
+    if (data == NULL) {
+        return 0;
+    }
+
+    DetectMarkDataFree(data);
+    return 1;
+}
+
+/**
+ * \test MarkTestParse04 is a test for a invalid mark value
+ *
+ *  \retval 1 on succces
+ *  \retval 0 on failure
+ */
+static int MarkTestParse04 (void) {
+    DetectMarkData *data;
+
+    data = DetectMarkParse("0x1g/0xff");
+
+    if (data == NULL) {
+        return 0;
+    }
+
+    DetectMarkDataFree(data);
+    return 1;
+}
+
+
+
+#endif /* UNITTESTS */
+
+/**
+ * \brief this function registers unit tests for Mark
+ */
+void MarkRegisterTests(void) {
+#if defined UNITTESTS && defined NFQ
+    UtRegisterTest("MarkTestParse01", MarkTestParse01, 1);
+    UtRegisterTest("MarkTestParse02", MarkTestParse02, 0);
+    UtRegisterTest("MarkTestParse03", MarkTestParse03, 1);
+    UtRegisterTest("MarkTestParse04", MarkTestParse04, 0);
+#endif /* UNITTESTS */
+}
diff --git a/src/detect-mark.h b/src/detect-mark.h
new file mode 100644
index 0000000..3c3b859
--- /dev/null
+++ b/src/detect-mark.h
@@ -0,0 +1,61 @@
+/* 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 at regit.org>
+ *
+ * Based on detect-mark.h by Breno Silva <breno.silva at gmail.com>
+ *
+ * Implements the nfq_set_mark keyword
+ */
+
+#ifndef __DETECT_MARK_H__
+#define __DETECT_MARK_H__
+
+#include "decode.h"
+#include "detect.h"
+
+/**
+ * \struct DetectMarkData_
+ * DetectMarkData_ is used to store nfq_set_mark: input value
+ */
+
+/**
+ * \typedef DetectMarkData
+ * A typedef for DetectMarkData_
+ */
+
+typedef struct DetectMarkData_ {
+    uint32_t mark;  /**< Rule mark */
+    uint32_t mask;  /**< Rule mask */
+} DetectMarkData;
+
+/**
+ * Registration function for nfq_set_mark: keyword
+ */
+
+void DetectMarkRegister (void);
+
+/**
+ * This function registers unit tests for Mark
+ */
+
+void MarkRegisterTests(void);
+
+#endif /*__DETECT_MARK_H__ */
diff --git a/src/detect.c b/src/detect.c
index 9511b4e..b7505e4 100644
--- a/src/detect.c
+++ b/src/detect.c
@@ -3965,6 +3965,7 @@ void SigTableSetup(void) {
     DetectFragBitsRegister();
     DetectFragOffsetRegister();
     DetectGidRegister();
+    DetectMarkRegister();
     DetectCsumRegister();
     DetectStreamSizeRegister();
     DetectTtlRegister();
diff --git a/src/detect.h b/src/detect.h
index eadbf75..94fd5b9 100644
--- a/src/detect.h
+++ b/src/detect.h
@@ -40,6 +40,7 @@
 #include "util-radix-tree.h"
 
 #include "detect-threshold.h"
+#include "detect-mark.h"
 //#include "detect-engine-tag.h"
 
 #define COUNTER_DETECT_ALERTS 1
@@ -969,6 +970,7 @@ enum {
     DETECT_FRAGBITS,
     DETECT_FRAGOFFSET,
     DETECT_GID,
+    DETECT_MARK,
 
     DETECT_AL_TLS_VERSION,
     DETECT_AL_HTTP_COOKIE,
-- 
1.7.1




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