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-----Original Message----- From: Marcks, Harrison <harrison.mar...@ncr.com> Sent: 29 June 2021 16:50 To: qemu-devel@nongnu.org Cc: berra...@redhat.com; Marcks, Harrison <harrison.mar...@ncr.com> Subject: [PATCH] crypto tls session: GNUTLS internal buffer is now cleared of stale data >From 7a95cd3f827be55153e7e457caa89351c48f247d Mon Sep 17 00:00:00 2001 From: harrison marcks <harrison.mar...@ncr.com> Date: Tue, 29 Jun 2021 16:50:00 +0100 Subject: [PATCH] crypto tls session: GNUTLS internal buffer is now cleared of stale data QEMU Serial devices only request up their "ITL" level. As the GNUTLS is not a socket proper, if the data on the line exceeds this level then QEMU won't go back and look for it. The fix adds a watch on the tls channel that uses an internal gnutls function to check pending records. Then changes the condition in the tls-channel watch to read from the buffer again (if there are indeed records still pending) Signed-off-by: harrison marcks <harrison.mar...@ncr.com> --- crypto/tlssession.c | 18 ++++++++ crypto/trace-events | 1 + include/crypto/tlssession.h | 28 ++++++++++++ include/io/channel-tls.h | 2 + io/channel-tls.c | 89 ++++++++++++++++++++++++++++++++++++- io/trace-events | 7 +++ 6 files changed, 144 insertions(+), 1 deletion(-) diff --git a/crypto/tlssession.c b/crypto/tlssession.c index 33203e8ca7..94bd464516 100644 --- a/crypto/tlssession.c +++ b/crypto/tlssession.c @@ -457,6 +457,24 @@ qcrypto_tls_session_write(QCryptoTLSSession *session, } +QCryptoTLSSessionRecordStatus +qcrypto_tls_session_read_check_buffer(QCryptoTLSSession *session) { + QCryptoTLSSessionRecordStatus status = QCRYPTO_TLS_RECORD_EMPTY; + + if (gnutls_record_check_pending(session->handle) > 0) { + status = QCRYPTO_TLS_RECORDS_PENDING; + } + + trace_qcrypto_tls_session_read_check_buffer( + session + , status + , gnutls_record_check_pending(session->handle) + ); + return status; +} + + ssize_t qcrypto_tls_session_read(QCryptoTLSSession *session, char *buf, diff --git a/crypto/trace-events b/crypto/trace-events index 9e594d30e8..d47edf4050 100644 --- a/crypto/trace-events +++ b/crypto/trace-events @@ -21,3 +21,4 @@ qcrypto_tls_creds_x509_load_cert_list(void *creds, const char *file) "TLS creds # tlssession.c qcrypto_tls_session_new(void *session, void *creds, const char *hostname, const char *authzid, int endpoint) "TLS session new session=%p creds=%p hostname=%s authzid=%s endpoint=%d" qcrypto_tls_session_check_creds(void *session, const char *status) "TLS session check creds session=%p status=%s" +qcrypto_tls_session_read_check_buffer(void* session, int status, long recordsN) "TLS session buffer check session=%p status=%d records pending=%ld" diff --git a/include/crypto/tlssession.h b/include/crypto/tlssession.h index 15b9cef086..4108271d62 100644 --- a/include/crypto/tlssession.h +++ b/include/crypto/tlssession.h @@ -321,4 +321,32 @@ int qcrypto_tls_session_get_key_size(QCryptoTLSSession *sess, */ char *qcrypto_tls_session_get_peer_name(QCryptoTLSSession *sess); +/** + * QCryptoTLSSessionRecordStatus: + * enum definitions for telling outside functions whether + * there are "records"/bytes waiting to be read in GNUTLS. + * + * QCRYPTO_TLS_RECORD_NULL is an empty/init state + * + */ +typedef enum { + QCRYPTO_TLS_RECORD_NULL, /* empty state */ + QCRYPTO_TLS_RECORD_EMPTY, + QCRYPTO_TLS_RECORDS_PENDING +} QCryptoTLSSessionRecordStatus; + +/** + * qcrypto_tls_session_read_check_buffer: + * @session: the TLS session object + * + * checks the internal GNUTLS buffer for the remaining bytes and + * returns one of: + * QCRYPTO_TLS_RECORD_EMPTY - No pending bytes + * QCRYPTO_TLS_RECORDS_PENDING - pending bytes + * + * Returns: QCryptoTLSSessionRecordStatus */ +QCryptoTLSSessionRecordStatus +qcrypto_tls_session_read_check_buffer(QCryptoTLSSession *session); + #endif /* QCRYPTO_TLSSESSION_H */ diff --git a/include/io/channel-tls.h b/include/io/channel-tls.h index fdbdf12feb..401fe786a2 100644 --- a/include/io/channel-tls.h +++ b/include/io/channel-tls.h @@ -29,6 +29,7 @@ #define QIO_CHANNEL_TLS(obj) \ OBJECT_CHECK(QIOChannelTLS, (obj), TYPE_QIO_CHANNEL_TLS) +typedef struct QIOChannelTLSSource QIOChannelTLSSource; typedef struct QIOChannelTLS QIOChannelTLS; /** @@ -49,6 +50,7 @@ struct QIOChannelTLS { QIOChannel *master; QCryptoTLSSession *session; QIOChannelShutdown shutdown; + QIOChannelTLSSource *source; }; /** diff --git a/io/channel-tls.c b/io/channel-tls.c index 7ec8ceff2f..77b80f2bf8 100644 --- a/io/channel-tls.c +++ b/io/channel-tls.c @@ -24,6 +24,12 @@ #include "io/channel-tls.h" #include "trace.h" +struct QIOChannelTLSSource { + GSource parent; + GIOCondition condition; + QIOChannelTLS *tioc; +}; + static ssize_t qio_channel_tls_write_handler(const char *buf, size_t len, @@ -269,6 +275,10 @@ static ssize_t qio_channel_tls_readv(QIOChannel *ioc, ssize_t ret = qcrypto_tls_session_read(tioc->session, iov[i].iov_base, iov[i].iov_len); + trace_qio_channel_tls_readv_iov_len(tioc->session + , iov[i].iov_base + , iov[i].iov_len); + if (ret < 0) { if (errno == EAGAIN) { if (got) { @@ -290,6 +300,15 @@ static ssize_t qio_channel_tls_readv(QIOChannel *ioc, break; } } + + if (qcrypto_tls_session_read_check_buffer(tioc->session) + == QCRYPTO_TLS_RECORDS_PENDING) { + tioc->source->condition |= G_IO_IN; + trace_qio_channel_tls_readv_extra_records(tioc->session + , tioc->source->condition + , got); + } + return got; } @@ -385,12 +404,80 @@ static void qio_channel_tls_set_aio_fd_handler(QIOChannel *ioc, qio_channel_set_aio_fd_handler(tioc->master, ctx, io_read, io_write, opaque); } +static gboolean +qio_channel_tls_source_check(GSource *source); + +static gboolean +qio_channel_tls_source_prepare(GSource *source, + gint *timeout) { + *timeout = -1; + trace_qio_channel_tls_source_prepare(source, *timeout); + return qio_channel_tls_source_check(source); +} + +static gboolean +qio_channel_tls_source_check(GSource *source) { + QIOChannelTLSSource *tsource = (QIOChannelTLSSource *)source; + trace_qio_channel_tls_source_check(tsource->condition); + return (G_IO_IN | G_IO_OUT) & tsource->condition; } + +static gboolean +qio_channel_tls_source_dispatch(GSource *source, + GSourceFunc callback, + gpointer user_data) { + QIOChannelFunc func = (QIOChannelFunc)callback; + QIOChannelTLSSource *tsource = (QIOChannelTLSSource *)source; + trace_qio_channel_tls_source_dispatch(tsource->tioc + , tsource->condition + , func); + + return (*func)(QIO_CHANNEL(tsource->tioc), + ((G_IO_IN | G_IO_OUT) & tsource->condition), + user_data); +} + +static void +qio_channel_tls_source_finalize(GSource *source) { + QIOChannelTLSSource *tsource = (QIOChannelTLSSource *)source; + trace_qio_channel_tls_source_finalize(tsource, tsource->tioc); + + object_unref(OBJECT(tsource->tioc)); +} + +GSourceFuncs qio_channel_tls_source_funcs = { + qio_channel_tls_source_prepare, + qio_channel_tls_source_check, + qio_channel_tls_source_dispatch, + qio_channel_tls_source_finalize +}; + + static GSource *qio_channel_tls_create_watch(QIOChannel *ioc, GIOCondition condition) { QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc); - return qio_channel_create_watch(tioc->master, condition); + QIOChannelTLSSource *tsource; + GSource *source; + + source = g_source_new(&qio_channel_tls_source_funcs, + sizeof(QIOChannelTLSSource)); + tsource = (QIOChannelTLSSource *)source; + + tsource->tioc = tioc; + tioc->source = tsource; + object_ref(OBJECT(tioc)); + + tsource->condition = condition; + trace_qio_channel_tls_create_watch(tsource + , tioc + , condition); + return source; } QCryptoTLSSession * diff --git a/io/trace-events b/io/trace-events index d7bc70b966..2f82c15e68 100644 --- a/io/trace-events +++ b/io/trace-events @@ -42,6 +42,13 @@ qio_channel_tls_handshake_fail(void *ioc) "TLS handshake fail ioc=%p" qio_channel_tls_handshake_complete(void *ioc) "TLS handshake complete ioc=%p" qio_channel_tls_credentials_allow(void *ioc) "TLS credentials allow ioc=%p" qio_channel_tls_credentials_deny(void *ioc) "TLS credentials deny ioc=%p" +qio_channel_tls_source_prepare(void *source, int timeout) "TLS source=%p prepare timeout=%d" +qio_channel_tls_source_check(int condition) "TLS source condition=%d" +qio_channel_tls_source_dispatch(void* channel_p, int condition, void* func) "TLS dispatch source=%p condition=%d callback func=%p" +qio_channel_tls_source_finalize(void* source_p, void* channel_p) "TLS source finalize source=%p ioc=%p" +qio_channel_tls_create_watch(void* tsource, void* tioc, int condition) "TLS create watch source=%p channel=%p condition=%d" +qio_channel_tls_readv_extra_records(void* session_p, int condition, long got) "TLS readv extra recs session=%p condition=%d got=%ld" +qio_channel_tls_readv_iov_len(void* session_p, void* iov_base, long iov_len) "TLS readv iov len session=%p iov_base=%p iov_len=%ld" # channel-websock.c qio_channel_websock_new_server(void *ioc, void *master) "Websock new client ioc=%p master=%p" -- 2.17.1