From 39015a6f3a0d4f9ca2041b9227094f0bcc2217e9 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Daniel=20P=2E=20Berrang=C3=A9?= Date: Tue, 1 May 2018 11:55:02 +0100 Subject: [PATCH] tests: rewrite socket to do something sensible and reliable MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The current socket test is rather crazy in that it sets up a server listening for sockets and then runs a client connect call, relying on the fact that the kernel will accept this despite the application not having called accept() yet. It then closes the client socket and calls accept() on the server. On Linux accept() will always see that the client has gone and so skip the rest of the code. On FreeBSD, however, the accept sometimes succeeds, causing us to then go into code that attempts to read and write to the client which will fail aborting the test. The accept() never succeeds on FreeBSD guests with a single CPU, but as you add more CPUs, accept() becomes more and more likely to succeed, giving a 100% failure rate for the test when using 8 CPUs. This completely rewrites the test so that it is avoids this designed in race condition. We simply spawn a background thread to act as the client, which will read a byte from the server and write it back again. The main thread can now properly listen and accept the client in a synchronous manner avoiding any races. Reviewed-by: Andrea Bolognani Signed-off-by: Daniel P. Berrangé --- tests/virnetsockettest.c | 143 +++++++++++++++++++++++++++++++++------ 1 file changed, 121 insertions(+), 22 deletions(-) diff --git a/tests/virnetsockettest.c b/tests/virnetsockettest.c index e463d432ff..cccb90d0be 100644 --- a/tests/virnetsockettest.c +++ b/tests/virnetsockettest.c @@ -115,6 +115,56 @@ checkProtocols(bool *hasIPv4, bool *hasIPv6, return ret; } +struct testClientData { + const char *path; + const char *cnode; + const char *portstr; +}; + +static void +testSocketClient(void *opaque) +{ + struct testClientData *data = opaque; + char c; + virNetSocketPtr csock = NULL; + + if (data->path) { + if (virNetSocketNewConnectUNIX(data->path, false, + NULL, &csock) < 0) + return; + } else { + if (virNetSocketNewConnectTCP(data->cnode, data->portstr, + AF_UNSPEC, + &csock) < 0) + return; + } + + virNetSocketSetBlocking(csock, true); + + if (virNetSocketRead(csock, &c, 1) != 1) { + VIR_DEBUG("Cannot read from server"); + goto done; + } + if (virNetSocketWrite(csock, &c, 1) != 1) { + VIR_DEBUG("Cannot write to server"); + goto done; + } + + done: + virObjectUnref(csock); +} + + +static void +testSocketIncoming(virNetSocketPtr sock, + int events ATTRIBUTE_UNUSED, + void *opaque) +{ + virNetSocketPtr *retsock = opaque; + VIR_DEBUG("Incoming sock=%p events=%d\n", sock, events); + *retsock = sock; +} + struct testSocketData { const char *lnode; @@ -122,18 +172,25 @@ struct testSocketData { const char *cnode; }; -static int testSocketAccept(const void *opaque) + +static int +testSocketAccept(const void *opaque) { virNetSocketPtr *lsock = NULL; /* Listen socket */ size_t nlsock = 0, i; virNetSocketPtr ssock = NULL; /* Server socket */ - virNetSocketPtr csock = NULL; /* Client socket */ + virNetSocketPtr rsock = NULL; /* Incoming client socket */ const struct testSocketData *data = opaque; int ret = -1; char portstr[100]; char *tmpdir = NULL; char *path = NULL; char template[] = "/tmp/libvirt_XXXXXX"; + virThread th; + struct testClientData cdata = { 0 }; + bool goodsock = false; + char a = 'a'; + char b = '\0'; if (!data) { virNetSocketPtr usock; @@ -155,50 +212,90 @@ static int testSocketAccept(const void *opaque) lsock[0] = usock; nlsock = 1; + + cdata.path = path; } else { snprintf(portstr, sizeof(portstr), "%d", data->port); if (virNetSocketNewListenTCP(data->lnode, portstr, AF_UNSPEC, &lsock, &nlsock) < 0) goto cleanup; + + cdata.cnode = data->cnode; + cdata.portstr = portstr; } for (i = 0; i < nlsock; i++) { if (virNetSocketListen(lsock[i], 0) < 0) goto cleanup; + + if (virNetSocketAddIOCallback(lsock[i], + VIR_EVENT_HANDLE_READABLE, + testSocketIncoming, + &rsock, + NULL) < 0) { + goto cleanup; + } } - if (!data) { - if (virNetSocketNewConnectUNIX(path, false, NULL, &csock) < 0) - goto cleanup; - } else { - if (virNetSocketNewConnectTCP(data->cnode, portstr, - AF_UNSPEC, - &csock) < 0) - goto cleanup; - } + if (virThreadCreate(&th, true, + testSocketClient, + &cdata) < 0) + goto cleanup; - virObjectUnref(csock); + while (rsock == NULL) + virEventRunDefaultImpl(); for (i = 0; i < nlsock; i++) { - if (virNetSocketAccept(lsock[i], &ssock) != -1 && ssock) { - char c = 'a'; - if (virNetSocketWrite(ssock, &c, 1) != -1 && - virNetSocketRead(ssock, &c, 1) != -1) { - VIR_DEBUG("Unexpected client socket present"); - goto cleanup; - } + if (lsock[i] == rsock) { + goodsock = true; + break; } - virObjectUnref(ssock); - ssock = NULL; } + if (!goodsock) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + "Unexpected server socket seen"); + goto join; + } + + if (virNetSocketAccept(rsock, &ssock) < 0) + goto join; + + if (!ssock) { + virReportError(VIR_ERR_INTERNAL_ERROR, "%s", + "Client went away unexpectedly"); + goto join; + } + + virNetSocketSetBlocking(ssock, true); + + if (virNetSocketWrite(ssock, &a, 1) < 0 || + virNetSocketRead(ssock, &b, 1) < 0) { + goto join; + } + + if (a != b) { + virReportError(VIR_ERR_INTERNAL_ERROR, + "Bad data received '%x' != '%x'", a, b); + goto join; + } + + virObjectUnref(ssock); + ssock = NULL; + ret = 0; + join: + virThreadJoin(&th); + cleanup: virObjectUnref(ssock); - for (i = 0; i < nlsock; i++) + for (i = 0; i < nlsock; i++) { + virNetSocketRemoveIOCallback(lsock[i]); + virNetSocketClose(lsock[i]); virObjectUnref(lsock[i]); + } VIR_FREE(lsock); VIR_FREE(path); if (tmpdir) @@ -431,6 +528,8 @@ mymain(void) signal(SIGPIPE, SIG_IGN); + virEventRegisterDefaultImpl(); + #ifdef HAVE_IFADDRS_H if (checkProtocols(&hasIPv4, &hasIPv6, &freePort) < 0) { fprintf(stderr, "Cannot identify IPv4/6 availability\n");