Add (experimental) support for using multiple pcap devices to acquire packets from. Just passing multiple -i <dev> options on the commandline will activate this. Windows not yet supported.

src/runmodes.c

@@ -2074,37 +2074,80 @@ int RunModeIdsPfring4(DetectEngineCtx *de_ctx, char *iface) {
 int RunModeIdsPcapAuto(DetectEngineCtx *de_ctx, char *iface) {
     SCEnter();
     /* tname = Detect + cpuid, this is 11bytes length as max */
-    char tname[12];
+    char tname[16];
     uint16_t cpu = 0;
+    TmModule *tm_module;
+    uint16_t thread;
 
     RunModeInitialize();
+    TimeModeSetLive();
 
     /* Available cpus */
     uint16_t ncpus = UtilCpuGetNumProcessorsOnline();
+    int npcap = PcapLiveGetDeviceCount();
 
-    TimeModeSetLive();
-    /* create the threads */
-    ThreadVars *tv_receivepcap = TmThreadCreatePacketHandler("ReceivePcap","packetpool","packetpool","pickup-queue","simple","1slot");
-    if (tv_receivepcap == NULL) {
-        printf("ERROR: TmThreadsCreate failed\n");
-        exit(EXIT_FAILURE);
-    }
-    TmModule *tm_module = TmModuleGetByName("ReceivePcap");
-    if (tm_module == NULL) {
-        printf("ERROR: TmModuleGetByName failed for ReceivePcap\n");
-        exit(EXIT_FAILURE);
-    }
-    Tm1SlotSetFunc(tv_receivepcap,tm_module,(void *)iface);
+    if (npcap == 1) {
+        /* create the threads */
+        ThreadVars *tv_receivepcap = TmThreadCreatePacketHandler("ReceivePcap","packetpool","packetpool","pickup-queue","simple","1slot");
+        if (tv_receivepcap == NULL) {
+            printf("ERROR: TmThreadsCreate failed\n");
+            exit(EXIT_FAILURE);
+        }
+        tm_module = TmModuleGetByName("ReceivePcap");
+        if (tm_module == NULL) {
+            printf("ERROR: TmModuleGetByName failed for ReceivePcap\n");
+            exit(EXIT_FAILURE);
+        }
+        Tm1SlotSetFunc(tv_receivepcap,tm_module,(void *)iface);
 
-    if (threading_set_cpu_affinity) {
-        TmThreadSetCPUAffinity(tv_receivepcap, 0);
-        if (ncpus > 1)
-            TmThreadSetThreadPriority(tv_receivepcap, PRIO_MEDIUM);
-    }
+        if (threading_set_cpu_affinity) {
+            TmThreadSetCPUAffinity(tv_receivepcap, 0);
+            if (ncpus > 1)
+                TmThreadSetThreadPriority(tv_receivepcap, PRIO_MEDIUM);
+        }
+        if (TmThreadSpawn(tv_receivepcap) != TM_ECODE_OK) {
+            printf("ERROR: TmThreadSpawn failed\n");
+            exit(EXIT_FAILURE);
+        }
+    } else {
+        SCLogInfo("Using %d pcap device(s).", npcap);
 
-    if (TmThreadSpawn(tv_receivepcap) != TM_ECODE_OK) {
-        printf("ERROR: TmThreadSpawn failed\n");
-        exit(EXIT_FAILURE);
+        for (thread = 0; thread < npcap; thread++) {
+            char *pcap_dev = PcapLiveGetDevice(thread);
+            if (pcap_dev == NULL) {
+                printf("Failed to lookup pcap dev %d\n", thread);
+                exit(EXIT_FAILURE);
+            }
+            SCLogDebug("pcap_dev %s", pcap_dev);
+
+            snprintf(tname, sizeof(tname),"RecvPcap-%s", pcap_dev);
+            char *tnamec = SCStrdup(tname);
+            char *pcap_devc = SCStrdup(pcap_dev);
+
+            /* create the threads */
+            ThreadVars *tv_receivepcap = TmThreadCreatePacketHandler(tnamec,"packetpool","packetpool","pickup-queue","simple","1slot");
+            if (tv_receivepcap == NULL) {
+                printf("ERROR: TmThreadsCreate failed\n");
+                exit(EXIT_FAILURE);
+            }
+            tm_module = TmModuleGetByName("ReceivePcap");
+            if (tm_module == NULL) {
+                printf("ERROR: TmModuleGetByName failed for ReceivePcap\n");
+                exit(EXIT_FAILURE);
+            }
+            Tm1SlotSetFunc(tv_receivepcap,tm_module,(void *)pcap_devc);
+
+            if (threading_set_cpu_affinity) {
+                TmThreadSetCPUAffinity(tv_receivepcap, 0);
+                if (ncpus > 1)
+                    TmThreadSetThreadPriority(tv_receivepcap, PRIO_MEDIUM);
+            }
+
+            if (TmThreadSpawn(tv_receivepcap) != TM_ECODE_OK) {
+                printf("ERROR: TmThreadSpawn failed\n");
+                exit(EXIT_FAILURE);
+            }
+        }
     }
 
 #if defined(__SC_CUDA_SUPPORT__)
@@ -2265,7 +2308,6 @@ int RunModeIdsPcapAuto(DetectEngineCtx *de_ctx, char *iface) {
     if (thread_max < 1)
         thread_max = 1;
 
-    int thread;
     for (thread = 0; thread < thread_max; thread++) {
         snprintf(tname, sizeof(tname),"Detect%"PRIu16, thread+1);
         if (tname == NULL)

src/source-pcap.c

@@ -48,8 +48,19 @@
 extern uint8_t suricata_ctl_flags;
 extern int max_pending_packets;
 
+/** control how many packet libpcap may read in one go */
 static int pcap_max_read_packets = 0;
 
+/** storage for pcap device names */
+typedef struct PcapDevice_ {
+    char *dev;  /**< the device (e.g. "eth0") */
+    TAILQ_ENTRY(PcapDevice_) next;
+} PcapDevice;
+
+/** private device list */
+static TAILQ_HEAD(, PcapDevice_) pcap_devices =
+    TAILQ_HEAD_INITIALIZER(pcap_devices);
+
 /** max packets < 65536 */
 #define PCAP_FILE_MAX_PKTS 256
 
@@ -521,6 +532,66 @@ TmEcode DecodePcapThreadInit(ThreadVars *tv, void *initdata, void **data)
     SCReturnInt(TM_ECODE_OK);
 }
 
+/**
+ *  \brief Add a pcap device for monitoring
+ *
+ *  \param dev string with the device name
+ *
+ *  \retval 0 on success.
+ *  \retval -1 on failure.
+ */
+int PcapLiveRegisterDevice(char *dev)
+{
+    PcapDevice *pd = SCMalloc(sizeof(PcapDevice));
+    if (pd == NULL) {
+        return -1;
+    }
+
+    pd->dev = SCStrdup(dev);
+    TAILQ_INSERT_TAIL(&pcap_devices, pd, next);
+
+    SCLogDebug("Pcap device \"%s\" registered.", dev);
+    return 0;
+}
+
+/**
+ *  \brief Get the number of registered devices
+ *
+ *  \retval cnt the number of registered devices
+ */
+int PcapLiveGetDeviceCount(void) {
+    int i = 0;
+    PcapDevice *pd;
+
+    TAILQ_FOREACH(pd, &pcap_devices, next) {
+        i++;
+    }
+
+    return i;
+}
+
+/**
+ *  \brief Get a pointer to the device at idx
+ *
+ *  \param number idx of the device in our list
+ *
+ *  \retval ptr pointer to the string containing the device
+ *  \retval NULL on error
+ */
+char *PcapLiveGetDevice(int number) {
+    int i = 0;
+    PcapDevice *pd;
+
+    TAILQ_FOREACH(pd, &pcap_devices, next) {
+        if (i == number) {
+            return pd->dev;
+        }
+
+        i++;
+    }
+    return NULL;
+}
+
 void PcapTranslateIPToDevice(char *pcap_dev, size_t len)
 {
 	char errbuf[PCAP_ERRBUF_SIZE];

src/source-pcap.h

@@ -28,6 +28,10 @@ void TmModuleReceivePcapRegister (void);
 void TmModuleDecodePcapRegister (void);
 void PcapTranslateIPToDevice(char *pcap_dev, size_t len);
 
+int PcapLiveRegisterDevice(char *);
+int PcapLiveGetDeviceCount(void);
+char *PcapLiveGetDevice(int);
+
 /* XXX replace with user configurable options */
 #define LIBPCAP_SNAPLEN     1518
 #define LIBPCAP_COPYWAIT    500

src/suricata.c

@@ -638,6 +638,17 @@ int main(int argc, char **argv)
         case 'i':
             if (run_mode == MODE_UNKNOWN) {
                 run_mode = MODE_PCAP_DEV;
+                PcapLiveRegisterDevice(optarg);
+            } else if (run_mode == MODE_PCAP_DEV) {
+#ifdef OS_WIN32
+                SCLogError(SC_ERR_PCAP_MULTI_DEV_NO_SUPPORT, "pcap multi dev "
+                        "support is not (yet) supported on Windows.");
+                exit(EXIT_FAILURE);
+#else
+                SCLogWarning(SC_WARN_PCAP_MULTI_DEV_EXPERIMENTAL, "using "
+                        "multiple pcap devices to get packets is experimental.");
+                PcapLiveRegisterDevice(optarg);
+#endif
             } else {
                 SCLogError(SC_ERR_MULTIPLE_RUN_MODE, "more than one run mode "
                                                      "has been specified");
@@ -645,7 +656,7 @@ int main(int argc, char **argv)
                 exit(EXIT_FAILURE);
             }
 			memset(pcap_dev, 0, sizeof(pcap_dev));
-			      strncpy(pcap_dev, optarg, ((strlen(optarg) < sizeof(pcap_dev)) ? (strlen(optarg)) : (sizeof(pcap_dev)-1)));
+            strlcpy(pcap_dev, optarg, ((strlen(optarg) < sizeof(pcap_dev)) ? (strlen(optarg)+1) : (sizeof(pcap_dev))));
             break;
         case 'l':
             if (ConfSet("default-log-dir", optarg, 0) != 1) {

src/util-error.c

@@ -192,6 +192,8 @@ const char * SCErrorToString(SCError err)
         CASE_CODE (SC_ERR_DCERPC);
         CASE_CODE (SC_ERR_AHO_CORASICK);
         CASE_CODE (SC_ERR_REFERENCE_CONFIG);
+        CASE_CODE (SC_WARN_PCAP_MULTI_DEV_EXPERIMENTAL);
+        CASE_CODE (SC_ERR_PCAP_MULTI_DEV_NO_SUPPORT);
 
         default:
             return "UNKNOWN_ERROR";

src/util-error.h

@@ -203,6 +203,8 @@ typedef enum {
     SC_ERR_DETECT_PREPARE,          /**< preparing the detection engine failed */
     SC_ERR_AHO_CORASICK,
     SC_ERR_REFERENCE_CONFIG,
+    SC_WARN_PCAP_MULTI_DEV_EXPERIMENTAL,
+    SC_ERR_PCAP_MULTI_DEV_NO_SUPPORT,
 } SCError;
 
 const char *SCErrorToString(SCError);