Adding upstream version 1:7.0.3.upstream/1%7.0.3

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 407 insertions, 0 deletions

diff --git a/src/detect-id.c b/src/detect-id.c
new file mode 100644
index 0000000..5239288
--- /dev/null
+++ b/src/detect-id.c
@@ -0,0 +1,407 @@
+/* Copyright (C) 2007-2021 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 Pablo Rincon Crespo <pablo.rincon.crespo@gmail.com>
+ *
+ * Implements the id keyword
+ */
+
+#include "suricata-common.h"
+#include "decode.h"
+#include "detect.h"
+
+#include "detect-parse.h"
+#include "detect-engine.h"
+#include "detect-engine-mpm.h"
+#include "detect-engine-prefilter-common.h"
+
+#include "detect-id.h"
+#include "flow.h"
+#include "flow-var.h"
+
+#include "util-debug.h"
+#include "util-byte.h"
+#include "util-unittest.h"
+#include "util-unittest-helper.h"
+
+/**
+ * \brief Regex for parsing "id" option, matching number or "number"
+ */
+#define PARSE_REGEX  "^\\s*([0-9]{1,5}|\"[0-9]{1,5}\")\\s*$"
+
+static DetectParseRegex parse_regex;
+
+static int DetectIdMatch (DetectEngineThreadCtx *, Packet *,
+        const Signature *, const SigMatchCtx *);
+static int DetectIdSetup (DetectEngineCtx *, Signature *, const char *);
+#ifdef UNITTESTS
+static void DetectIdRegisterTests(void);
+#endif
+void DetectIdFree(DetectEngineCtx *, void *);
+
+static int PrefilterSetupId(DetectEngineCtx *de_ctx, SigGroupHead *sgh);
+static bool PrefilterIdIsPrefilterable(const Signature *s);
+
+/**
+ * \brief Registration function for keyword: id
+ */
+void DetectIdRegister (void)
+{
+    sigmatch_table[DETECT_ID].name = "id";
+    sigmatch_table[DETECT_ID].desc = "match on a specific IP ID value";
+    sigmatch_table[DETECT_ID].url = "/rules/header-keywords.html#id";
+    sigmatch_table[DETECT_ID].Match = DetectIdMatch;
+    sigmatch_table[DETECT_ID].Setup = DetectIdSetup;
+    sigmatch_table[DETECT_ID].Free  = DetectIdFree;
+#ifdef UNITTESTS
+    sigmatch_table[DETECT_ID].RegisterTests = DetectIdRegisterTests;
+#endif
+    sigmatch_table[DETECT_ID].SupportsPrefilter = PrefilterIdIsPrefilterable;
+    sigmatch_table[DETECT_ID].SetupPrefilter = PrefilterSetupId;
+
+    DetectSetupParseRegexes(PARSE_REGEX, &parse_regex);
+}
+
+/**
+ * \brief This function is used to match the specified id on a packet
+ *
+ * \param t pointer to thread vars
+ * \param det_ctx pointer to the pattern matcher thread
+ * \param p pointer to the current packet
+ * \param m pointer to the sigmatch that we will cast into DetectIdData
+ *
+ * \retval 0 no match
+ * \retval 1 match
+ */
+static int DetectIdMatch (DetectEngineThreadCtx *det_ctx, Packet *p,
+                          const Signature *s, const SigMatchCtx *ctx)
+{
+    const DetectIdData *id_d = (const DetectIdData *)ctx;
+
+    /**
+     * To match a ipv4 packet with a "id" rule
+     */
+    if (!PKT_IS_IPV4(p) || PKT_IS_PSEUDOPKT(p)) {
+        return 0;
+    }
+
+    if (id_d->id == IPV4_GET_IPID(p)) {
+        SCLogDebug("IPV4 Proto and matched with ip_id: %u.\n",
+                    id_d->id);
+        return 1;
+    }
+
+    return 0;
+}
+
+/**
+ * \brief This function is used to parse IPV4 ip_id passed via keyword: "id"
+ *
+ * \param idstr Pointer to the user provided id option
+ *
+ * \retval id_d pointer to DetectIdData on success
+ * \retval NULL on failure
+ */
+static DetectIdData *DetectIdParse (const char *idstr)
+{
+    uint16_t temp;
+    DetectIdData *id_d = NULL;
+    int res = 0;
+    size_t pcre2len;
+    pcre2_match_data *match = NULL;
+
+    int ret = DetectParsePcreExec(&parse_regex, &match, idstr, 0, 0);
+
+    if (ret < 1 || ret > 3) {
+        SCLogError("invalid id option '%s'. The id option "
+                   "value must be in the range %u - %u",
+                idstr, DETECT_IPID_MIN, DETECT_IPID_MAX);
+        goto error;
+    }
+
+    char copy_str[128] = "";
+    char *tmp_str;
+    pcre2len = sizeof(copy_str);
+    res = pcre2_substring_copy_bynumber(match, 1, (PCRE2_UCHAR8 *)copy_str, &pcre2len);
+    if (res < 0) {
+        SCLogError("pcre2_substring_copy_bynumber failed");
+        goto error;
+    }
+    tmp_str = copy_str;
+
+    /* Let's see if we need to scape "'s */
+    if (tmp_str[0] == '"')
+    {
+        tmp_str[strlen(tmp_str) - 1] = '\0';
+        tmp_str += 1;
+    }
+
+    /* ok, fill the id data */
+    if (StringParseUint16(&temp, 10, 0, (const char *)tmp_str) < 0) {
+        SCLogError("invalid id option '%s'", tmp_str);
+        goto error;
+    }
+
+    /* We have a correct id option */
+    id_d = SCMalloc(sizeof(DetectIdData));
+    if (unlikely(id_d == NULL))
+        goto error;
+
+    id_d->id = temp;
+
+    SCLogDebug("detect-id: will look for ip_id: %u\n", id_d->id);
+    pcre2_match_data_free(match);
+    return id_d;
+
+error:
+    if (match) {
+        pcre2_match_data_free(match);
+    }
+    return NULL;
+}
+
+/**
+ * \brief this function is used to add the parsed "id" option
+ * \brief into the current signature
+ *
+ * \param de_ctx pointer to the Detection Engine Context
+ * \param s pointer to the Current Signature
+ * \param idstr pointer to the user provided "id" option
+ *
+ * \retval 0 on Success
+ * \retval -1 on Failure
+ */
+int DetectIdSetup (DetectEngineCtx *de_ctx, Signature *s, const char *idstr)
+{
+    DetectIdData *id_d = NULL;
+    SigMatch *sm = NULL;
+
+    id_d = DetectIdParse(idstr);
+    if (id_d == NULL)
+        return -1;
+
+    /* Okay so far so good, lets get this into a SigMatch
+     * and put it in the Signature. */
+    sm = SigMatchAlloc();
+    if (sm == NULL) {
+        DetectIdFree(de_ctx, id_d);
+        return -1;
+    }
+
+    sm->type = DETECT_ID;
+    sm->ctx = (SigMatchCtx *)id_d;
+
+    SigMatchAppendSMToList(s, sm, DETECT_SM_LIST_MATCH);
+    s->flags |= SIG_FLAG_REQUIRE_PACKET;
+    return 0;
+}
+
+/**
+ * \brief this function will free memory associated with DetectIdData
+ *
+ * \param id_d pointer to DetectIdData
+ */
+void DetectIdFree(DetectEngineCtx *de_ctx, void *ptr)
+{
+    DetectIdData *id_d = (DetectIdData *)ptr;
+    SCFree(id_d);
+}
+
+/* prefilter code */
+
+static void
+PrefilterPacketIdMatch(DetectEngineThreadCtx *det_ctx, Packet *p, const void *pectx)
+{
+    const PrefilterPacketHeaderCtx *ctx = pectx;
+
+    if (!PKT_IS_IPV4(p) || PKT_IS_PSEUDOPKT(p)) {
+        return;
+    }
+
+    if (!PrefilterPacketHeaderExtraMatch(ctx, p))
+        return;
+
+    if (IPV4_GET_IPID(p) == ctx->v1.u16[0])
+    {
+        SCLogDebug("packet matches IP id %u", ctx->v1.u16[0]);
+        PrefilterAddSids(&det_ctx->pmq, ctx->sigs_array, ctx->sigs_cnt);
+    }
+}
+
+static void
+PrefilterPacketIdSet(PrefilterPacketHeaderValue *v, void *smctx)
+{
+    const DetectIdData *a = smctx;
+    v->u16[0] = a->id;
+}
+
+static bool
+PrefilterPacketIdCompare(PrefilterPacketHeaderValue v, void *smctx)
+{
+    const DetectIdData *a = smctx;
+    if (v.u16[0] == a->id)
+        return true;
+    return false;
+}
+
+static int PrefilterSetupId(DetectEngineCtx *de_ctx, SigGroupHead *sgh)
+{
+    return PrefilterSetupPacketHeader(de_ctx, sgh, DETECT_ID,
+        PrefilterPacketIdSet,
+        PrefilterPacketIdCompare,
+        PrefilterPacketIdMatch);
+}
+
+static bool PrefilterIdIsPrefilterable(const Signature *s)
+{
+    const SigMatch *sm;
+    for (sm = s->init_data->smlists[DETECT_SM_LIST_MATCH] ; sm != NULL; sm = sm->next) {
+        switch (sm->type) {
+            case DETECT_ID:
+                return true;
+        }
+    }
+    return false;
+}
+
+#ifdef UNITTESTS /* UNITTESTS */
+
+/**
+ * \test DetectIdTestParse01 is a test to make sure that we parse the "id"
+ *       option correctly when given valid id option
+ */
+static int DetectIdTestParse01 (void)
+{
+    DetectIdData *id_d = DetectIdParse(" 35402 ");
+
+    FAIL_IF_NULL(id_d);
+    FAIL_IF_NOT(id_d->id == 35402);
+
+    DetectIdFree(NULL, id_d);
+
+    PASS;
+}
+
+/**
+ * \test DetectIdTestParse02 is a test to make sure that we parse the "id"
+ *       option correctly when given an invalid id option
+ *       it should return id_d = NULL
+ */
+static int DetectIdTestParse02 (void)
+{
+    DetectIdData *id_d = DetectIdParse("65537");
+
+    FAIL_IF_NOT_NULL(id_d);
+
+    PASS;
+}
+
+/**
+ * \test DetectIdTestParse03 is a test to make sure that we parse the "id"
+ *       option correctly when given an invalid id option
+ *       it should return id_d = NULL
+ */
+static int DetectIdTestParse03 (void)
+{
+    DetectIdData *id_d = DetectIdParse("12what?");
+
+    FAIL_IF_NOT_NULL(id_d);
+
+    PASS;
+}
+
+/**
+ * \test DetectIdTestParse04 is a test to make sure that we parse the "id"
+ *       option correctly when given valid id option but wrapped with "'s
+ */
+static int DetectIdTestParse04 (void)
+{
+    /* yep, look if we trim blank spaces correctly and ignore "'s */
+    DetectIdData *id_d = DetectIdParse(" \"35402\" ");
+
+    FAIL_IF_NULL(id_d);
+    FAIL_IF_NOT(id_d->id == 35402);
+
+    DetectIdFree(NULL, id_d);
+
+    PASS;
+}
+
+/**
+ * \test DetectIdTestSig01
+ * \brief Test to check "id" keyword with constructed packets
+ */
+static int DetectIdTestMatch01(void)
+{
+    uint8_t *buf = (uint8_t *)"Hi all!";
+    uint16_t buflen = strlen((char *)buf);
+    Packet *p[3];
+    p[0] = UTHBuildPacket((uint8_t *)buf, buflen, IPPROTO_TCP);
+    p[1] = UTHBuildPacket((uint8_t *)buf, buflen, IPPROTO_UDP);
+    p[2] = UTHBuildPacket((uint8_t *)buf, buflen, IPPROTO_ICMP);
+
+    FAIL_IF_NULL(p[0]);
+    FAIL_IF_NULL(p[1]);
+    FAIL_IF_NULL(p[2]);
+
+    /* TCP IP id = 1234 */
+    p[0]->ip4h->ip_id = htons(1234);
+
+    /* UDP IP id = 5678 */
+    p[1]->ip4h->ip_id = htons(5678);
+
+    /* UDP IP id = 91011 */
+    p[2]->ip4h->ip_id = htons(5101);
+
+    const char *sigs[3];
+    sigs[0]= "alert ip any any -> any any (msg:\"Testing id 1\"; id:1234; sid:1;)";
+    sigs[1]= "alert ip any any -> any any (msg:\"Testing id 2\"; id:5678; sid:2;)";
+    sigs[2]= "alert ip any any -> any any (msg:\"Testing id 3\"; id:5101; sid:3;)";
+
+    uint32_t sid[3] = {1, 2, 3};
+
+    uint32_t results[3][3] = {
+                              /* packet 0 match sid 1 but should not match sid 2 */
+                              {1, 0, 0},
+                              /* packet 1 should not match */
+                              {0, 1, 0},
+                              /* packet 2 should not match */
+                              {0, 0, 1} };
+
+    FAIL_IF_NOT(UTHGenericTest(p, 3, sigs, sid, (uint32_t *)results, 3));
+
+    UTHFreePackets(p, 3);
+
+    PASS;
+}
+
+/**
+ * \brief this function registers unit tests for DetectId
+ */
+void DetectIdRegisterTests(void)
+{
+    UtRegisterTest("DetectIdTestParse01", DetectIdTestParse01);
+    UtRegisterTest("DetectIdTestParse02", DetectIdTestParse02);
+    UtRegisterTest("DetectIdTestParse03", DetectIdTestParse03);
+    UtRegisterTest("DetectIdTestParse04", DetectIdTestParse04);
+    UtRegisterTest("DetectIdTestMatch01", DetectIdTestMatch01);
+
+}
+#endif /* UNITTESTS */