crypto: push error reporting into TLS session I/O APIs

The current TLS session I/O APIs just return a synthetic errno
value on error, which has been translated from a gnutls error
value. This looses a large amount of valuable information that
distinguishes different scenarios.

Pushing population of the "Error *errp" object into the TLS
session I/O APIs gives more detailed error information.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

1 files changed, 20 insertions, 28 deletions

diff --git a/io/channel-tls.c b/io/channel-tls.c
index 67b9700..9d8bb15 100644
--- a/io/channel-tls.c
+++ b/io/channel-tls.c
@@ -277,24 +277,19 @@ static ssize_t qio_channel_tls_readv(QIOChannel *ioc,
     ssize_t got = 0;
 
     for (i = 0 ; i < niov ; i++) {
-        ssize_t ret = qcrypto_tls_session_read(tioc->session,
-                                               iov[i].iov_base,
-                                               iov[i].iov_len);
-        if (ret < 0) {
-            if (errno == EAGAIN) {
-                if (got) {
-                    return got;
-                } else {
-                    return QIO_CHANNEL_ERR_BLOCK;
-                }
-            } else if (errno == ECONNABORTED &&
-                       (qatomic_load_acquire(&tioc->shutdown) &
-                        QIO_CHANNEL_SHUTDOWN_READ)) {
-                return 0;
+        ssize_t ret = qcrypto_tls_session_read(
+            tioc->session,
+            iov[i].iov_base,
+            iov[i].iov_len,
+            qatomic_load_acquire(&tioc->shutdown) & QIO_CHANNEL_SHUTDOWN_READ,
+            errp);
+        if (ret == QCRYPTO_TLS_SESSION_ERR_BLOCK) {
+            if (got) {
+                return got;
+            } else {
+                return QIO_CHANNEL_ERR_BLOCK;
             }
-
-            error_setg_errno(errp, errno,
-                             "Cannot read from TLS channel");
+        } else if (ret < 0) {
             return -1;
         }
         got += ret;
@@ -321,18 +316,15 @@ static ssize_t qio_channel_tls_writev(QIOChannel *ioc,
     for (i = 0 ; i < niov ; i++) {
         ssize_t ret = qcrypto_tls_session_write(tioc->session,
                                                 iov[i].iov_base,
-                                                iov[i].iov_len);
-        if (ret <= 0) {
-            if (errno == EAGAIN) {
-                if (done) {
-                    return done;
-                } else {
-                    return QIO_CHANNEL_ERR_BLOCK;
-                }
+                                                iov[i].iov_len,
+                                                errp);
+        if (ret == QCRYPTO_TLS_SESSION_ERR_BLOCK) {
+            if (done) {
+                return done;
+            } else {
+                return QIO_CHANNEL_ERR_BLOCK;
             }
-
-            error_setg_errno(errp, errno,
-                             "Cannot write to TLS channel");
+        } else if (ret < 0) {
             return -1;
         }
         done += ret;