[PATCH v1 1/1] rpc: Add the retry argument for virNetTLSSession{Read,Write}

From: Hyman Huang <yong.huang(a)smartx.com&gt; As advised by the GNU TLS, the caller should attempt again if the gnutls_record_{recv,send} return EAGAIN or EINTR; check the following link to view the details: https://www.gnutls.org/manual/html_node/Data-transfer-and-termination.html Add the retry parameter for virNetTLSSession{Read,Write} functions in accordance with this guideline. This prevents the upper application from encountering the following error message when it calls the virConnectOpenAuth API: Unable to read TLS confirmation: Resource temporarily unavailable Signed-off-by: Hyman Huang <yong.huang(a)smartx.com&gt; --- src/rpc/virnetclient.c | 2 +- src/rpc/virnetsocket.c | 4 ++-- src/rpc/virnettlscontext.c | 28 ++++++++++++++++++++++++++-- src/rpc/virnettlscontext.h | 6 ++++-- 4 files changed, 33 insertions(+), 7 deletions(-) diff --git a/src/rpc/virnetclient.c b/src/rpc/virnetclient.c index 92933220e2..5340db4211 100644 --- a/src/rpc/virnetclient.c +++ b/src/rpc/virnetclient.c @@ -1003,7 +1003,7 @@ int virNetClientSetTLSSession(virNetClient *client, ignore_value(pthread_sigmask(SIG_SETMASK, &oldmask, NULL)); #endif /* !WIN32 */ - len = virNetTLSSessionRead(client->tls, buf, 1); + len = virNetTLSSessionRead(client->tls, buf, 1, true); if (len < 0 && errno != ENOMSG) { virReportSystemError(errno, "%s", _("Unable to read TLS confirmation")); diff --git a/src/rpc/virnetsocket.c b/src/rpc/virnetsocket.c index e8fc2d5f7d..6774dd4a4b 100644 --- a/src/rpc/virnetsocket.c +++ b/src/rpc/virnetsocket.c @@ -1739,7 +1739,7 @@ static ssize_t virNetSocketReadWire(virNetSocket *sock, char *buf, size_t len) if (sock->tlsSession && virNetTLSSessionGetHandshakeStatus(sock->tlsSession) == VIR_NET_TLS_HANDSHAKE_COMPLETE) { - ret = virNetTLSSessionRead(sock->tlsSession, buf, len); + ret = virNetTLSSessionRead(sock->tlsSession, buf, len, false); } else { ret = read(sock->fd, buf, len); } @@ -1807,7 +1807,7 @@ static ssize_t virNetSocketWriteWire(virNetSocket *sock, const char *buf, size_t if (sock->tlsSession && virNetTLSSessionGetHandshakeStatus(sock->tlsSession) == VIR_NET_TLS_HANDSHAKE_COMPLETE) { - ret = virNetTLSSessionWrite(sock->tlsSession, buf, len); + ret = virNetTLSSessionWrite(sock->tlsSession, buf, len, false); } else { ret = write(sock->fd, buf, len); /* sc_avoid_write */ } diff --git a/src/rpc/virnettlscontext.c b/src/rpc/virnettlscontext.c index e8023133b4..92d909c0b7 100644 --- a/src/rpc/virnettlscontext.c +++ b/src/rpc/virnettlscontext.c @@ -679,16 +679,28 @@ void virNetTLSSessionSetIOCallbacks(virNetTLSSession *sess, ssize_t virNetTLSSessionWrite(virNetTLSSession *sess, - const char *buf, size_t len) + const char *buf, size_t len, + bool retry) { ssize_t ret; + rewrite: virObjectLock(sess); ret = gnutls_record_send(sess->session, buf, len); if (ret >= 0) goto cleanup; + if (retry && (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)) { + /* + * GNU TLS advises calling the function again to obtain the data if EAGAIN is returned. + * See reference: https://www.gnutls.org/manual/html_node/Data-transfer-and-termination.html + * */ + VIR_DEBUG("Try writing data from the TLS session again"); + virObjectUnlock(sess); + goto rewrite; + } + switch (ret) { case GNUTLS_E_AGAIN: errno = EAGAIN; @@ -712,16 +724,28 @@ ssize_t virNetTLSSessionWrite(virNetTLSSession *sess, } ssize_t virNetTLSSessionRead(virNetTLSSession *sess, - char *buf, size_t len) + char *buf, size_t len, + bool retry) { ssize_t ret; + reread: virObjectLock(sess); ret = gnutls_record_recv(sess->session, buf, len); if (ret >= 0) goto cleanup; + if (retry && (ret == GNUTLS_E_AGAIN || ret == GNUTLS_E_INTERRUPTED)) { + /* + * GNU TLS advises calling the function again to obtain the data if EAGAIN is returned. + * See reference: https://www.gnutls.org/manual/html_node/Data-transfer-and-termination.html + * */ + VIR_DEBUG("Try reading data from the TLS session again"); + virObjectUnlock(sess); + goto reread; + } + switch (ret) { case GNUTLS_E_AGAIN: errno = EAGAIN; diff --git a/src/rpc/virnettlscontext.h b/src/rpc/virnettlscontext.h index 11c954ce4b..da26d7836b 100644 --- a/src/rpc/virnettlscontext.h +++ b/src/rpc/virnettlscontext.h @@ -81,9 +81,11 @@ void virNetTLSSessionSetIOCallbacks(virNetTLSSession *sess, void *opaque); ssize_t virNetTLSSessionWrite(virNetTLSSession *sess, - const char *buf, size_t len); + const char *buf, size_t len, + bool retry); ssize_t virNetTLSSessionRead(virNetTLSSession *sess, - char *buf, size_t len); + char *buf, size_t len, + bool retry); int virNetTLSSessionHandshake(virNetTLSSession *sess); -- 2.27.0