+/*
+ test-example/bogus-setup-request 127.0.0.1 19098 test-example/inside/inside 127.0.0.1 16096 test-example/outside/outside
+ */
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#include <netdb.h>
+
+#include <assert.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+ /*
+ | 00000 00 00 00 00 00 00 00 01 01 01 01 01 00 1a 74 65 ........ ......te |
+ ~~~~~~~~~~~ ~~~~~~~~~~~ ~~~~~~~~~~~ ~~~~~|~~~~~
+ sessionid sender's type sender's
+ zero in index fixed for name
+ msg1 msg1
+
+ | 00010 73 74 2d 65 78 61 6d 70 6c 65 2f 69 6e 73 69 64 st-examp le/insid |
+ | 00020 65 2f 69 6e 73 69 64 65 00 1c 74 65 73 74 2d 65 e/inside ..test-e |
+ ~~~~~|~~~~~~~~~~~~~~~~~
+ recipient's name
+
+ | 00030 78 61 6d 70 6c 65 2f 6f 75 74 73 69 64 65 2f 6f xample/o utside/o |
+ | 00040 75 74 73 69 64 65 8d f0 3f 35 d6 c8 1f c0 utside.. ?5.... |
+ ~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~
+ sender's nonce
+ */
+
+typedef struct {
+ const char *name;
+ union {
+ struct sockaddr sa;
+ struct sockaddr_in sin;
+ };
+} Ep;
+
+static void endaddr(Ep *ep, char **argv, int base) {
+ int r;
+ ep->sin.sin_family=AF_INET;
+ r=inet_aton(argv[base],&ep->sin.sin_addr); assert(r);
+ ep->sin.sin_port=htons(atoi(argv[base+1]));
+ ep->name=argv[base+2];
+}
+
+static void endname(uint8_t **msgp, const Ep *ep) {
+ int l=strlen(ep->name); assert(l<=65535);
+ *(*msgp)++ = l>>8;
+ *(*msgp)++ = l;
+ memcpy(*msgp, ep->name, l);
+ *msgp += l;
+}
+
+static Ep us, them;
+
+int main(int argc, char **argv) {
+ int r;
+
+ assert(argc==7);
+
+ endaddr(&us,argv,1);
+ endaddr(&them,argv,4);
+
+ static const uint8_t mprefix[]={
+ 0x00, 0x00, 0x00, 0x00,
+ 0x00, 0x00, 0x00, 0x01,
+ 0x01, 0x01, 0x01, 0x01,
+ };
+ static const uint8_t msuffix[]={
+ /* our nonce, fixed he he */
+ 0x8d, 0xf0, 0x3f, 0x35, 0xd6, 0xc8, 0x1f, 0xc0
+ };
+ int msglen= (sizeof(mprefix) +
+ 2+strlen(us.name) +
+ 2+strlen(them.name) +
+ sizeof(msuffix));
+ uint8_t msg[msglen];
+ uint8_t *msgp=msg;
+
+#define PREFIXSUFFIX(prefixsuffix) do { \
+ memcpy(msgp,prefixsuffix,sizeof(prefixsuffix)); \
+ msgp += sizeof(prefixsuffix); \
+ }while(0)
+
+ PREFIXSUFFIX(mprefix);
+
+ endname(&msgp,&us);
+ endname(&msgp,&them);
+
+ PREFIXSUFFIX(msuffix);
+
+ assert(msgp == msg+msglen);
+
+ struct protoent *proto=getprotobyname("udp");
+ int fd=socket(AF_INET, SOCK_DGRAM, proto->p_proto);
+ r=bind(fd,&us.sa,sizeof(us.sin)); if (r) { perror("bind us2"); exit(1); }
+
+ for (;;) {
+ r=sendto(fd,msg,msglen,0,&them.sa,sizeof(them.sin));
+ if (r < 0) perror("sendto");
+
+ r=getchar();
+ if (r==EOF) {
+ if (ferror(stdin)) { perror("getchar"); exit(1); }
+ break;
+ }
+ if (r!='\n')
+ break;
+ }
+ exit(0);
+}