//
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// Copyright 2018 Staysail Systems, Inc. <info@staysail.tech>
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// Copyright 2018 Capitar IT Group BV <info@capitar.com>
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//
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// This software is supplied under the terms of the MIT License, a
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// copy of which should be located in the distribution where this
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// file was obtained (LICENSE.txt). A copy of the license may also be
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// found online at https://opensource.org/licenses/MIT.
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//
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//
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// This is just a simple REQ/REP demonstration application. It is derived
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// from the legacy nanomsg demonstration program of the same name, written
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// by Tim Dysinger, but updated for nng. I've also updated it to pass simpler
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// binary data rather than strings over the network.
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//
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// The program implements a simple RPC style service, which just returns
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// the date in UNIX time (seconds since 1970).
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//
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#include <stdint.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <time.h>
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#include <nng/nng.h>
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#include <nng/protocol/reqrep0/rep.h>
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#include <nng/protocol/reqrep0/req.h>
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#define CLIENT "client"
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#define SERVER "server"
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#define DATECMD 1
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#define PUT64(ptr, u) \
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do { \
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(ptr)[0] = (uint8_t)(((uint64_t)(u)) >> 56); \
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(ptr)[1] = (uint8_t)(((uint64_t)(u)) >> 48); \
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(ptr)[2] = (uint8_t)(((uint64_t)(u)) >> 40); \
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(ptr)[3] = (uint8_t)(((uint64_t)(u)) >> 32); \
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(ptr)[4] = (uint8_t)(((uint64_t)(u)) >> 24); \
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(ptr)[5] = (uint8_t)(((uint64_t)(u)) >> 16); \
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(ptr)[6] = (uint8_t)(((uint64_t)(u)) >> 8); \
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(ptr)[7] = (uint8_t)((uint64_t)(u)); \
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} while (0)
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#define GET64(ptr, v) \
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v = (((uint64_t)((uint8_t)(ptr)[0])) << 56) + \
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(((uint64_t)((uint8_t)(ptr)[1])) << 48) + \
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(((uint64_t)((uint8_t)(ptr)[2])) << 40) + \
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(((uint64_t)((uint8_t)(ptr)[3])) << 32) + \
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(((uint64_t)((uint8_t)(ptr)[4])) << 24) + \
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(((uint64_t)((uint8_t)(ptr)[5])) << 16) + \
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(((uint64_t)((uint8_t)(ptr)[6])) << 8) + \
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(((uint64_t)(uint8_t)(ptr)[7]))
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void
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fatal(const char *func, int rv)
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{
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fprintf(stderr, "%s: %s\n", func, nng_strerror(rv));
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exit(1);
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}
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void
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showdate(time_t now)
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{
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struct tm *info = localtime(&now);
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printf("%s", asctime(info));
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}
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int
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server(const char *url)
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{
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nng_socket sock;
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int rv;
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if ((rv = nng_rep0_open(&sock)) != 0) {
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fatal("nng_rep0_open", rv);
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}
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if ((rv = nng_listen(sock, url, NULL, 0)) != 0) {
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fatal("nng_listen", rv);
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}
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for (;;) {
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char * buf = NULL;
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size_t sz;
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uint64_t val;
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if ((rv = nng_recv(sock, &buf, &sz, NNG_FLAG_ALLOC)) != 0) {
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fatal("nng_recv", rv);
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}
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if ((sz == sizeof(uint64_t)) &&
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((GET64(buf, val)) == DATECMD)) {
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time_t now;
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printf("SERVER: RECEIVED DATE REQUEST\n");
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now = time(&now);
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printf("SERVER: SENDING DATE: ");
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showdate(now);
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// Reuse the buffer. We know it is big enough.
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PUT64(buf, (uint64_t) now);
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rv = nng_send(sock, buf, sz, NNG_FLAG_ALLOC);
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if (rv != 0) {
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fatal("nng_send", rv);
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}
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continue;
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}
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// Unrecognized command, so toss the buffer.
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nng_free(buf, sz);
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}
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}
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int
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client(const char *url)
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{
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nng_socket sock;
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int rv;
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size_t sz;
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char * buf = NULL;
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uint8_t cmd[sizeof(uint64_t)];
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PUT64(cmd, DATECMD);
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if ((rv = nng_req0_open(&sock)) != 0) {
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fatal("nng_socket", rv);
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}
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if ((rv = nng_dial(sock, url, NULL, 0)) != 0) {
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fatal("nng_dial", rv);
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}
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printf("CLIENT: SENDING DATE REQUEST\n");
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if ((rv = nng_send(sock, cmd, sizeof(cmd), 0)) != 0) {
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fatal("nng_send", rv);
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}
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if ((rv = nng_recv(sock, &buf, &sz, NNG_FLAG_ALLOC)) != 0) {
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fatal("nng_recv", rv);
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}
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if (sz == sizeof(uint64_t)) {
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uint64_t now;
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GET64(buf, now);
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printf("CLIENT: RECEIVED DATE: ");
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showdate((time_t) now);
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} else {
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printf("CLIENT: GOT WRONG SIZE!\n");
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}
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// This assumes that buf is ASCIIZ (zero terminated).
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nng_free(buf, sz);
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nng_close(sock);
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return (0);
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}
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int
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main(const int argc, const char **argv)
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{
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if ((argc > 1) && (strcmp(CLIENT, argv[1]) == 0))
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return (client(argv[2]));
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if ((argc > 1) && (strcmp(SERVER, argv[1]) == 0))
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return (server(argv[2]));
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fprintf(stderr, "Usage: reqrep %s|%s <URL> ...\n", CLIENT, SERVER);
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return (1);
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}
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