Add LIBSSH2_TRACE_SOCKET context for tracing send() and recv()

Helpful in debugging the -39 errors.

include/libssh2.h

@@ -883,6 +883,7 @@ LIBSSH2_API int libssh2_trace(LIBSSH2_SESSION *session, int bitmask);
 #define LIBSSH2_TRACE_SFTP  (1<<6)
 #define LIBSSH2_TRACE_ERROR (1<<7)
 #define LIBSSH2_TRACE_PUBLICKEY (1<<8)
+#define LIBSSH2_TRACE_SOCKET (1<<9)
 
 #ifdef __cplusplus
 } /* extern "C" */

src/libssh2_priv.h

@@ -1022,6 +1022,8 @@ struct _LIBSSH2_MAC_METHOD
 #define LIBSSH2_DBG_SFTP    6
 #define LIBSSH2_DBG_ERROR   7
 #define LIBSSH2_DBG_PUBLICKEY   8
+#define LIBSSH2_DBG_SOCKET  9
+
 #ifdef LIBSSH2DEBUG
 void _libssh2_debug(LIBSSH2_SESSION * session, int context, const char *format,
                     ...);
@@ -1271,4 +1273,7 @@ int _libssh2_pem_decode_integer(unsigned char **data, unsigned int *datalen,
     } while(1)
 
 
+#define ARRAY_SIZE(a) (sizeof ((a)) / sizeof ((a)[0]))
+
+
 #endif /* LIBSSH2_H */

src/misc.c

@@ -320,7 +320,7 @@ _libssh2_debug(LIBSSH2_SESSION * session, int context, const char *format, ...)
     va_list vargs;
     struct timeval now;
     static int firstsec;
-    static const char *const contexts[9] = {
+    static const char *const contexts[] = {
         "Unknown",
         "Transport",
         "Key Ex",
@@ -330,9 +330,10 @@ _libssh2_debug(LIBSSH2_SESSION * session, int context, const char *format, ...)
         "SFTP",
         "Failure Event",
         "Publickey",
+        "Socket",
     };
 
-    if (context < 1 || context > 8) {
+    if (context < 1 || context >= (int)ARRAY_SIZE(contexts)) {
         context = 0;
     }
     if (!(session->showmask & (1 << context))) {

src/session.c

@@ -111,6 +111,12 @@ banner_receive(LIBSSH2_SESSION * session)
 
         ret = _libssh2_recv(session->socket_fd, &c, 1,
                             LIBSSH2_SOCKET_RECV_FLAGS(session));
+        if (ret < 0)
+            _libssh2_debug(session, LIBSSH2_DBG_SOCKET,
+                           "Error recving %d bytes to %p: %d", 1, &c, errno);
+        else
+            _libssh2_debug(session, LIBSSH2_DBG_SOCKET,
+                           "Recved %d bytes to %p", ret, &c);
 
         if (ret < 0) {
             if (errno == EAGAIN) {
@@ -217,6 +223,15 @@ banner_send(LIBSSH2_SESSION * session)
                         banner + session->banner_TxRx_total_send,
                         banner_len - session->banner_TxRx_total_send,
                         LIBSSH2_SOCKET_SEND_FLAGS(session));
+    if (ret < 0)
+        _libssh2_debug(session, LIBSSH2_DBG_SOCKET,
+                       "Error sending %d bytes: %d",
+                       banner_len - session->banner_TxRx_total_send, errno);
+    else
+        _libssh2_debug(session, LIBSSH2_DBG_SOCKET,
+                       "Sent %d/%d bytes at %p+%d", ret,
+                       banner_len - session->banner_TxRx_total_send,
+                       banner, session->banner_TxRx_total_send);
 
     if (ret != (banner_len - session->banner_TxRx_total_send)) {
         if ((ret > 0) || ((ret == -1) && (errno == EAGAIN))) {

src/transport.c

@@ -355,6 +355,15 @@ int _libssh2_transport_read(LIBSSH2_SESSION * session)
                 _libssh2_recv(session->socket_fd, &p->buf[remainbuf],
                               PACKETBUFSIZE - remainbuf,
                               LIBSSH2_SOCKET_RECV_FLAGS(session));
+            if (nread < 0)
+                _libssh2_debug(session, LIBSSH2_DBG_SOCKET,
+                               "Error recving %d bytes to %p+%d: %d",
+                               PACKETBUFSIZE - remainbuf, p->buf, remainbuf,
+                               errno);
+            else
+                _libssh2_debug(session, LIBSSH2_DBG_SOCKET,
+                               "Recved %d/%d bytes to %p+%d", nread,
+                               PACKETBUFSIZE - remainbuf, p->buf, remainbuf);
             if (nread <= 0) {
                 /* check if this is due to EAGAIN and return the special
                    return code if so, error out normally otherwise */
@@ -602,6 +611,13 @@ send_existing(LIBSSH2_SESSION * session, unsigned char *data,
 
     rc = _libssh2_send(session->socket_fd, &p->outbuf[p->osent], length,
                        LIBSSH2_SOCKET_SEND_FLAGS(session));
+    if (rc < 0)
+        _libssh2_debug(session, LIBSSH2_DBG_SOCKET,
+                       "Error sending %d bytes: %d", length, errno);
+    else
+        _libssh2_debug(session, LIBSSH2_DBG_SOCKET,
+                       "Sent %d/%d bytes at %p+%d", rc, length, p->outbuf,
+                       p->osent);
 
     if(rc > 0) {
         debugdump(session, "libssh2_transport_write send()",
@@ -776,6 +792,12 @@ _libssh2_transport_write(LIBSSH2_SESSION * session, unsigned char *data,
 
     ret = _libssh2_send(session->socket_fd, p->outbuf, total_length,
                         LIBSSH2_SOCKET_SEND_FLAGS(session));
+    if (ret < 0)
+        _libssh2_debug(session, LIBSSH2_DBG_SOCKET,
+                       "Error sending %d bytes: %d", total_length, errno);
+    else
+        _libssh2_debug(session, LIBSSH2_DBG_SOCKET, "Sent %d/%d bytes at %p",
+                       ret, total_length, p->outbuf);
 
     if (ret != -1) {
         debugdump(session, "libssh2_transport_write send()", p->outbuf, ret);