Add option to specify DCCP service code

diff --git a/README b/README
index c6d1dd3086c4e5e72cc317c6bde8124239c866f9..c7f913dd3f875de18263c847796718455aaf2dab 100644 (file)
--- a/README
+++ b/README
@@ -11,7 +11,7 @@ makefile as needed. Contact me, if major problems arise.
 
 Usage is pretty simple:
 dccpping: [-v] [-V] [-h] [-n] [-6|-4] [-c count] [-p port] [-i interval]
-          [-t ttl] [-S srcaddress] remote_host
+          [-t ttl] [-s service_code] [-S srcaddress] remote_host
 
           -v   Verbose. May be repeated for aditional verbosity.
           -V   Version information
@@ -24,6 +24,7 @@ dccpping: [-v] [-V] [-h] [-n] [-6|-4] [-c count] [-p port] [-i interval]
                  -p   The DCCP port to send requests to. The default is 33434.
                  -i   Interval between requests in seconds. The default is 1 second.
                  -t   The TTL to set in the sent requests. The default is 64.
+                 -s   Service Code. The DCCP service code to use when sending packets.
                  -S   Source Address. The address to send packets from. Should
                           only be needed if the autodetection fails.
                           

diff --git a/dccpping.c b/dccpping.c
index dd3fdf9855921f01471bbfc8e211c3a3ab2a5f26..4d1e528d66be43de6342f213f2a3a34d7178b374 100644 (file)
--- a/dccpping.c
+++ b/dccpping.c
@@ -45,16 +45,19 @@ Date: 11/2012
 #include "checksums.h"
 
 
-/*Use the DCCP source port to multiplex DCCP Ping streams by PID*/
-#define DCCP_SERVICE_CODE 0x50455246
+#define DEFAULT_SERVICE_CODE 0x50455246
 #define DEFAULT_PORT 33434
 
+
 #define DCCPPING_VERSION 1.0
 #define MAX(x,y) (x>y ? x : y)
 extern int errno;
 #ifndef NI_IDN
 #define NI_IDN 32
 #endif
+#ifndef SOL_DCCP
+#define SOL_DCCP 269
+#endif
 
 
 /*Structure for simpler IPv4/IPv6 Address handling*/
@@ -193,6 +196,7 @@ struct params{
        ipaddr_ptr_t src_addr;  /*Source Address*/
        int dccp_socket;                /*DCCP Socket used to grab src addr/port*/
        char* hostname;                 /*Originally requested hostname*/
+       unsigned int service_code;/*DCCP Service Code*/
 };
 
 
@@ -230,6 +234,7 @@ int main(int argc, char *argv[])
        char c;
        char *src=NULL;
        char *dst=NULL;
+       char *tmp;
 
        /*Set Defaults*/
        queue.head=NULL;
@@ -250,10 +255,11 @@ int main(int argc, char *argv[])
        parms.dccp_socket=-1;
        parms.no_resolve=0;
        parms.hostname=NULL;
+       parms.service_code=DEFAULT_SERVICE_CODE;
 
        sanitize_environment();
 
-       while ((c = getopt(argc, argv, "64vhnc:p:i:dt:S:")) != -1) {
+       while ((c = getopt(argc, argv, "64vVhnc:p:i:t:S:s:")) != -1) {
                switch (c) {
                        case '6':
                                parms.ip_type=AF_INET6;
@@ -288,6 +294,18 @@ int main(int argc, char *argv[])
                                parms.ttl = atoi(optarg);
                                if (parms.ttl < 1 || parms.ttl > 255) {
                                        dbgprintf(0,"Error: Invalid TTL\n");
+                                       exit(1);
+                               }
+                               break;
+                       case 's':
+                               parms.service_code=strtol(optarg,&tmp,0);
+                               if(*tmp!='\0'){
+                                       dbgprintf(0,"Error: Invalid Service Code\n");
+                                       exit(1);
+                               }
+                               if(parms.service_code<=0){
+                                       dbgprintf(0, "Error: Service Code MUST be positive");
+                                       exit(1);
                                }
                                break;
                        case 'S':
@@ -340,6 +358,7 @@ void getAddresses(char *src, char* dst){
        struct sockaddr_in* iv42;
        int addrlen;
        int err;
+       int opt;
 
        /*Lookup destination Address*/
        memset(&hint,0,sizeof(struct addrinfo));
@@ -452,6 +471,11 @@ void getAddresses(char *src, char* dst){
                        exit(1);
                }
        }
+       opt=htonl(parms.service_code);
+       if(setsockopt(parms.dccp_socket,SOL_DCCP, DCCP_SOCKOPT_SERVICE,&opt,sizeof(opt))<0){
+               dbgprintf(0, "Error: Failed setsockopt() on DCCP socket (%s)\n",strerror(errno));
+               exit(1);
+       }
 
        /*Connect socket to get source address/port*/
        if(parms.ip_type==AF_INET){
@@ -967,7 +991,7 @@ void buildRequestPacket(unsigned char* buffer, int *len, int seq){
        dhdr->dccph_seq2=htonl(0); //Reserved if using 48 bit sequence numbers
        dhdr->dccph_seq=htonl(0);  //High 16bits of sequence number. Always make 0 for simplicity.
        dhdre->dccph_seq_low=htonl(seq);
-       dhdrr->dccph_req_service=htonl(DCCP_SERVICE_CODE);
+       dhdrr->dccph_req_service=htonl(parms.service_code);
 
        /*Checksums*/
        if(parms.ip_type==AF_INET){
@@ -1258,7 +1282,7 @@ char* addr2str(ipaddr_ptr_t *res, int nores){
 void usage()
 {
        dbgprintf(0, "dccpping: [-v] [-V] [-h] [-n] [-6|-4] [-c count] [-p port] [-i interval]\n");
-       dbgprintf(0, "          [-t ttl] [-S srcaddress] remote_host\n");
+       dbgprintf(0, "          [-t ttl] [-s service_code] [-S srcaddress] remote_host\n");
        dbgprintf(0, "\n");
        dbgprintf(0, "          -v   Verbose. May be repeated for aditional verbosity.\n");
        dbgprintf(0, "          -V   Version information\n");