chore: add helper scripts

CMakeLists.txt

@@ -7,8 +7,15 @@ project(igmpgen VERSION 1.0)
 set(CMAKE_C_STANDARD 11)
 set(CMAKE_C_STANDARD_REQUIRED True)
 
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -ggdb -Wall -Werror -D_GNU_SOURCE -pedantic")
+
+
 # Add the executable
-add_executable(igmpgen src/igmpgen.c)
+add_executable(
+	igmpgen 
+	src/main.c
+	src/usage.c
+)
 
 # Detect the net library
 find_library(LIBNET_LIBRARY NAMES net libnet libnet1 REQUIRED)

build.sh

@@ -0,0 +1,5 @@
+#!/bin/sh
+
+mkdir -p _build
+cmake -S . -B _build -D CMAKE_BUILD_TYPE=Debug
+cmake --build _build

run.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+gdb _build/igmpgen 

src/ipg_types.h

@@ -0,0 +1,32 @@
+
+#ifndef IGP_TYPES_H
+#define IGP_TYPES_H
+
+#define IPOPT_RA                148             /* router alert */
+#define IGMP_V3_MEMBERSHIP_REPORT 0x22
+
+#include <sys/types.h>
+
+/* Structure to represent IGMP extra information */
+typedef struct {
+    u_int8_t igmp_version;
+    char *igmp_tag;
+    u_int8_t igmp_type;             /* IGMP type */
+    u_int8_t igmp_code;             /* routing code */
+    char *igmp_dst;
+    int group_override_dst;
+} ipg_igmp_extra_t;
+
+typedef struct {
+    char *device;
+    char *igmp_type_version; // Combined type and version
+    char *igmp_group;
+    char *source_ip_port; // Combined source IP and port
+    char *destination_ip_port; // Combined destination IP and port
+    int delay_between_packets; // Optional, can be 0 if not specified
+} ipg_cmdline_options_t;
+
+extern ipg_igmp_extra_t g_igmp_pkts[];
+
+#endif /* IGP_TYPES_H */
+

src/main.c

@@ -2,21 +2,21 @@
 #include <stdlib.h>
 #include <unistd.h>
 
+#include <sys/types.h>
+
+/* missing type definitions (depending on system) */
+typedef unsigned char           unchar;
+typedef unsigned short          ushort;
+typedef unsigned int            uint;
+typedef unsigned long           ulong;
+
 #include <libnet.h>
 #include <netinet/igmp.h>
 
-#define IPOPT_RA                148             /* router alert */
-#define IGMP_V3_MEMBERSHIP_REPORT 0x22
+#include "ipg_types.h"
 
-/* Structure to represent IGMP extra information */
-struct igmp_extra {
-    u_int8_t igmp_version;
-    char *igmp_tag;
-    u_int8_t igmp_type;             /* IGMP type */
-    u_int8_t igmp_code;             /* routing code */
-    char *igmp_dst;
-    int group_override_dst;
-} g_igmp_pkts[] = {
+/* global table of IGMP packet types*/
+ipg_igmp_extra_t g_igmp_pkts[] = {
     /* name,  type (or version+type), code */
     { 1, "query",  0x11, 0, "224.0.0.1", 0 },
     { 1, "report", 0x12, 0, "224.0.0.1", 1 },
@@ -27,11 +27,26 @@ struct igmp_extra {
     { 3, "report", 0x22, 1, "224.0.0.22", 0 },
 
     /* Note: end of list (please keep) */
-    { 0, 0, 0, 0 },
+    { 0, 0, 0, 0, 0, 0 },
 };
 
 void usage(char *);
 
+ipg_igmp_extra_t * igmp_packet_type_find(u_int8_t igmp_version, char *igmp_request) {
+    ipg_igmp_extra_t *pkt_ptr;
+
+    pkt_ptr = g_igmp_pkts;
+    while(pkt_ptr->igmp_version || pkt_ptr->igmp_tag){
+        // if ((strcasecmp(pkt_ptr->igmp_tag, optarg) == 0) 
+        if ((strcasecmp(pkt_ptr->igmp_tag, igmp_request) == 0) 
+                && (igmp_version == pkt_ptr->igmp_version)){
+            return pkt_ptr;
+        }
+        pkt_ptr++; 
+    }
+    return NULL;
+}
+
 int main(int argc, char **argv)
 {
     u_int32_t ip_src = 0;
@@ -40,17 +55,17 @@ int main(int argc, char **argv)
     char *igmp_group_str = NULL;
     char *ip_src_str = NULL;
     char *ip_dst_str = NULL;
+    u_char igmp_type = 0;
+    u_char igmp_code = 0;
+    ipg_igmp_extra_t *pkt_ptr;
+    int igmp_override;
 
     /* ports */
     u_short src_prt = 3141;
     u_short dst_prt = 5926;   
 
     /* igmp stuff */
-    u_char igmp_type = 0;
-    u_char igmp_code = 0;
     u_int8_t igmp_version = 0;
-    int igmp_override;
-    struct igmp_extra *pkt_ptr;
 
     int ip_src_test = 1;
     int ip_dst_test = 1;
@@ -65,9 +80,9 @@ int main(int argc, char **argv)
     char *device = "eth0";
     int c;                      
     char *cp = NULL; 
-    int found=0;
 
     printf("IGMP packet generator\n\n");
+    printf("Detected options:\n");
 
     /* Parsing command line */
     while((c = getopt(argc, argv, "i:t:g:d:s:")) != EOF)
@@ -86,30 +101,20 @@ int main(int argc, char **argv)
                 }
                 *cp++ = 0;
 
-                // igmp_version = (u_short)atoi(cp);
                 igmp_version = (u_short)atoi(optarg);
 
-                pkt_ptr = g_igmp_pkts;
-                while(pkt_ptr->igmp_version || pkt_ptr->igmp_tag){
-                    // if ((strcasecmp(pkt_ptr->igmp_tag, optarg) == 0) 
-                    if ((strcasecmp(pkt_ptr->igmp_tag, cp) == 0) 
-                            && (igmp_version == pkt_ptr->igmp_version)){
-                        found = 1;
-                        igmp_type = pkt_ptr->igmp_type;
-                        igmp_code = pkt_ptr->igmp_code;
-                        ip_dst_str = pkt_ptr->igmp_dst;
-                        igmp_override = pkt_ptr->group_override_dst;
-
-                        break;
-                    }
-                    pkt_ptr++; 
-                }
-                if (found){
-                    printf("  Packet = [%s] version [%d]\n", pkt_ptr->igmp_tag, igmp_version);
-                } else {
+                pkt_ptr = igmp_packet_type_find(igmp_version, cp);
+                if (!pkt_ptr) {
+                    printf("ERROR: Packet type %d.%s not found!\n", igmp_version, cp);
                     usage(argv[0]);
                     exit(1);
                 }
+
+                igmp_type = pkt_ptr->igmp_type;
+                igmp_code = pkt_ptr->igmp_code;
+                ip_dst_str = pkt_ptr->igmp_dst;
+                igmp_override = pkt_ptr->group_override_dst;
+                printf("  Packet = [%s] version [%d]\n", pkt_ptr->igmp_tag, igmp_version);
                 break;
 
             case 'g':
@@ -122,13 +127,14 @@ int main(int argc, char **argv)
                 // delay between packets in sec
                 break;
 
+            case 'd':
                 /*
-                 *  We expect the input to be of the form `ip.ip.ip.ip.port`.  We
+                 *  We expect the input to be of the form `ip.ip.ip.ip:port`.  We
                  *  point cp to the last dot of the IP address/port string and
                  *  then seperate them with a NULL byte.  The optarg now points to
                  *  just the IP address, and cp points to the port.
                  */
-            case 'd':
+
                 if ((cp = strrchr(optarg, ':')))
                 {
                     *cp++ = 0;
@@ -157,9 +163,18 @@ int main(int argc, char **argv)
                 exit(1);
         }
     }
-    if (!igmp_group_str || !device)
+
+    if (!igmp_group_str)
     {
         usage(argv[0]);
+        fprintf(stderr, "ERROR: missing destination IGMP group\n");
+        exit(EXIT_FAILURE);
+    }
+
+    if (!device)
+    {
+        usage(argv[0]);
+        fprintf(stderr, "ERROR: missing device\n");
         exit(EXIT_FAILURE);
     }
 
@@ -354,25 +369,4 @@ int main(int argc, char **argv)
     return (c == -1 ? EXIT_FAILURE : EXIT_SUCCESS);
 }
 
-void usage(char *name)
-{
-    struct igmp_extra *pkt_ptr;
-
-    fprintf(stderr, "Usage: %s [options]\n", name);
-    fprintf(stderr, "\nOptions:\n");
-    fprintf(stderr, "  -i <interface>   Specify the network interface (e.g., eth0)\n");
-    fprintf(stderr, "  -t <type>        Specify the IGMP packet type and version (e.g., 1.query)\n");
-    fprintf(stderr, "  -g <group>       Specify the IGMP group (e.g., 224.0.0.1)\n");
-    fprintf(stderr, "  -s <source>      Specify the source IP and port (e.g., 192.168.1.1:1234)\n");
-    fprintf(stderr, "  -d <destination> Specify the destination IP and port (e.g., 224.0.0.2:5678)\n");
-    fprintf(stderr, "  -n <number>      Specify delay between packets in seconds (optional)\n");
-
-    fprintf(stderr, "\nAvailable IGMP packet types:\n");
-    pkt_ptr = g_igmp_pkts;
-    while(pkt_ptr->igmp_version || pkt_ptr->igmp_tag){
-        fprintf(stderr," - %d.%s\n", pkt_ptr->igmp_version, pkt_ptr->igmp_tag);
-        pkt_ptr++; 
-    }
-}
-
 // vim: ts=4 sts=4 sw=4 et

src/usage.c

@@ -0,0 +1,30 @@
+
+#include <string.h>
+#include <sys/types.h>
+#include <stdio.h>
+
+#include "ipg_types.h"
+
+void usage(const char *name)
+{
+    ipg_igmp_extra_t *pkt_ptr;
+
+    fprintf(stderr, "Usage: %s [options]\n", basename(name));
+    fprintf(stderr, "\nOptions:\n");
+    fprintf(stderr, "  -i <interface>   Specify the network interface (e.g., eth0)\n");
+    fprintf(stderr, "  -t <type>        Specify the IGMP packet type and version (e.g., 1.query)\n");
+    fprintf(stderr, "  -g <group>       Specify the destination IGMP group (e.g., 224.0.0.1)\n");
+    fprintf(stderr, "  -s <source>      Specify the source IP and port (e.g., 192.168.1.1:1234)\n");
+    fprintf(stderr, "  -d <destination> Specify the destination IP and port (e.g., 224.0.0.2:5678)\n");
+    fprintf(stderr, "  -n <number>      Specify delay between packets in seconds (optional)\n");
+
+    fprintf(stderr, "\nAvailable IGMP packet types:\n");
+
+    pkt_ptr = g_igmp_pkts;
+    while(pkt_ptr->igmp_version || pkt_ptr->igmp_tag){
+        fprintf(stderr," - %d.%s\n", pkt_ptr->igmp_version, pkt_ptr->igmp_tag);
+        pkt_ptr++; 
+    }
+    fprintf(stderr, "\n");
+}
+