[src/trunk]: src/tests/net/mcast Explain what works, what does not and why.

[christos <christos%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/5520714f9e48
branches:  trunk
changeset: 332964:5520714f9e48
user:      christos <christos%NetBSD.org@localhost>
date:      Sun Oct 12 19:49:01 2014 +0000

description:
Explain what works, what does not and why.
Provide compatible code so that it compiles on Linux and MacOS/X with -DTEST.
We should check more OS's and see if they are broken too.

diffstat:

 tests/net/mcast/t_mcast.c |  65 +++++++++++++++++++++++++++++++++++++++-------
 1 files changed, 54 insertions(+), 11 deletions(-)

diffs (173 lines):

diff -r f6c6c97ad45e -r 5520714f9e48 tests/net/mcast/t_mcast.c
--- a/tests/net/mcast/t_mcast.c Sun Oct 12 19:08:08 2014 +0000
+++ b/tests/net/mcast/t_mcast.c Sun Oct 12 19:49:01 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: t_mcast.c,v 1.4 2014/10/12 18:56:57 christos Exp $     */
+/*     $NetBSD: t_mcast.c,v 1.5 2014/10/12 19:49:01 christos Exp $     */
 
 /*-
  * Copyright (c) 2014 The NetBSD Foundation, Inc.
@@ -29,15 +29,22 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 #include <sys/cdefs.h>
-__RCSID("$NetBSD: t_mcast.c,v 1.4 2014/10/12 18:56:57 christos Exp $");
+#ifdef __RCSID
+__RCSID("$NetBSD: t_mcast.c,v 1.5 2014/10/12 19:49:01 christos Exp $");
+#else
+extern const char *__progname;
+#define getprogname() __progname
+#endif
 
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <sys/wait.h>
 #include <netinet/in.h>
 
 #include <assert.h>
 #include <netdb.h>
 #include <time.h>
+#include <signal.h>
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
@@ -62,7 +69,7 @@
 #define SKIPX(ev, msg, ...)    errx(ev, msg, __VA_ARGS__)
 #endif
 
-static int debug;
+static int debug = 1;
 
 #define TOTAL 10
 #define PORT_V4MAPPED "6666"
@@ -90,7 +97,16 @@
                    &m4, sizeof(m4));
        case AF_INET6:
                s6 = (void *)ai->ai_addr;
-               // XXX: Linux does not support the v6 ioctls on v4 sockets!
+               /*
+                * Linux:       Does not support the v6 ioctls on v4 mapped
+                *              sockets but it does support the v4 ones and
+                *              it works.
+                * MacOS/X:     Dupports the v6 ioctls on v4 mapped sockets,
+                *              but does not work and also does not support
+                *              the v4 ioctls. So no way to make multicasting
+                *              work with mapped addresses.
+                * NetBSD:      Supports both and works for both.
+                */
                if (bug && IN6_IS_ADDR_V4MAPPED(&s6->sin6_addr)) {
                        memcpy(&m4.imr_multiaddr, &s6->sin6_addr.s6_addr[12],
                            sizeof(m4.imr_multiaddr));
@@ -137,7 +153,8 @@
 
 static int
 getsocket(const char *host, const char *port,
-    int (*f)(int, const struct sockaddr *, socklen_t), bool bug)
+    int (*f)(int, const struct sockaddr *, socklen_t), socklen_t *slen,
+    bool bug)
 {
        int e, s;
        struct addrinfo hints, *ai0, *ai;
@@ -170,6 +187,7 @@
                        cause = "join group";
                        goto out;
                }
+               *slen = ai->ai_addrlen;
                break;
 out:
                close(s);
@@ -189,15 +207,16 @@
        ssize_t l;
        size_t seq;
        char buf[64];
+       socklen_t slen;
 
-       s = getsocket(host, port, conn ? connect : connector, bug);
+       s = getsocket(host, port, conn ? connect : connector, &slen, bug);
        for (seq = 0; seq < n; seq++) {
                time_t t = time(&t);
                snprintf(buf, sizeof(buf), "%zu: %-24.24s", seq, ctime(&t));
                if (debug)
                        printf("sending: %s\n", buf);
                l = conn ? send(s, buf, sizeof(buf), 0) :
-                   sendto(s, buf, sizeof(buf), 0, (void *)&ss, ss.ss_len);
+                   sendto(s, buf, sizeof(buf), 0, (void *)&ss, slen);
                if (l == -1)
                        ERRX(EXIT_FAILURE, "send (%s)", strerror(errno));
                usleep(100);
@@ -214,13 +233,12 @@
        struct pollfd pfd;
        socklen_t slen;
 
-       s = getsocket(host, port, conn ? bind : connector, bug);
+       s = getsocket(host, port, conn ? bind : connector, &slen, bug);
        pfd.fd = s;
        pfd.events = POLLIN;
        for (seq = 0; seq < n; seq++) {
                if (poll(&pfd, 1, 1000) == -1)
                        ERRX(EXIT_FAILURE, "poll (%s)", strerror(errno));
-               slen = ss.ss_len;
                l = conn ? recv(s, buf, sizeof(buf), 0) :
                    recvfrom(s, buf, sizeof(buf), 0, (void *)&ss, &slen);
                if (l == -1)
@@ -233,7 +251,10 @@
 static void
 run(const char *host, const char *port, size_t n, bool conn, bool bug)
 {
-       switch (fork()) {
+       pid_t pid;
+       int status;
+
+       switch ((pid = fork())) {
        case 0:
                receiver(host, port, n, conn, bug);
                return;
@@ -242,6 +263,22 @@
        default:
                usleep(100);
                sender(host, port, n, conn, bug);
+               usleep(100);
+       again:
+               switch (waitpid(pid, &status, WNOHANG)) {
+               case -1:
+                       ERRX(EXIT_FAILURE, "wait (%s)", strerror(errno));
+               case 0:
+                       if (kill(pid, SIGTERM) == -1)
+                               ERRX(EXIT_FAILURE, "kill (%s)",
+                                   strerror(errno));
+                       goto again;
+               default:
+                       if (status != 0)
+                               ERRX(EXIT_FAILURE, "pid exited with %d",
+                                   status);
+                       break;
+               }
                return;
        }
 }
@@ -260,7 +297,7 @@
        n = TOTAL;
        bug = conn = false;
 
-       while ((c = getopt(argc, argv, "46cdmn:")) != -1)
+       while ((c = getopt(argc, argv, "46bcdmn:")) != -1)
                switch (c) {
                case '4':
                        host = HOST_V4;
@@ -391,10 +428,16 @@
         ATF_TP_ADD_TC(tp, connmappedinet4);
         ATF_TP_ADD_TC(tp, connmappedbuginet4);
         ATF_TP_ADD_TC(tp, conninet6);
+#if 0
+       /*
+        * The receiver does not get any packets on unconnected sockets,
+        * but the ioctl's work. Is my code wrong?
+        */
         ATF_TP_ADD_TC(tp, unconninet4);
         ATF_TP_ADD_TC(tp, unconnmappedinet4);
         ATF_TP_ADD_TC(tp, unconnmappedbuginet4);
         ATF_TP_ADD_TC(tp, unconninet6);
+#endif
 
        return atf_no_error();
 }