- Vlad Grachov brought the new function called

libssh2_session_block_directions() which returns a bitmask for what
  directions the connection blocks. It is to be used applications that use
  non-blocking sockets and when a libssh2 function returns
  LIBSSH2_ERROR_EAGAIN this function can be used to figure out in which
  direction the socket would block and thus it can wait for the socket to
  again be ready for communication in that direction before it calls libssh2
  again.

NEWS

@@ -1,7 +1,17 @@
 Version 0.19 ( )
 -------------------------------
 
-- Vincent Jaulin brought the new libssh2_channel_request_pty_size_ex() function.
+- Vlad Grachov brought the new function called
+  libssh2_session_block_directions() which returns a bitmask for what
+  directions the connection blocks. It is to be used applications that use
+  non-blocking sockets and when a libssh2 function returns
+  LIBSSH2_ERROR_EAGAIN this function can be used to figure out in which
+  direction the socket would block and thus it can wait for the socket to
+  again be ready for communication in that direction before it calls libssh2
+  again.
+
+- Vincent Jaulin brought the new libssh2_channel_request_pty_size_ex()
+  function.
 
 - Carlo Bramini fixed the build for msys+mingw. Bug #1943976.
 
@@ -16,8 +26,8 @@ Version 0.19 ( )
 - Based on a patch in bug #1878059 by Steven Ayre libssh2 now parses >2GB file
   sizes when downloading SCP files.
 
-- Bug #2064371 pointed out that the SSH2 banner may not use dash ('-'). Reported
+- Bug #2064371 pointed out that the SSH2 banner may not use dash
-  by Bjorn Stenborg.
+  ('-'). Reported by Bjorn Stenborg.
 
 - Sean Peterson fixed a key re-exchange bug:
   http://daniel.haxx.se/projects/libssh2/mail/libssh2-devel-archive-2008-06/0002.shtml

docs/Makefile.am

@@ -1,4 +1,4 @@
-# $Id: Makefile.am,v 1.28 2008/03/08 18:26:32 dottedmag Exp $
+# $Id: Makefile.am,v 1.29 2008/11/24 13:31:00 bagder Exp $
 
 EXTRA_DIST = template.3
 
@@ -29,6 +29,7 @@ dist_man_MANS = \
 	libssh2_scp_recv.3 \
 	libssh2_scp_send_ex.3 \
 	libssh2_session_abstract.3 \
+	libssh2_session_block_directions.3 \
 	libssh2_session_callback_set.3 \
 	libssh2_session_free.3 \
 	libssh2_session_disconnect_ex.3 \

include/libssh2.h

@@ -244,6 +244,11 @@ typedef struct _LIBSSH2_POLLFD {
 #define LIBSSH2_POLLFD_CHANNEL_CLOSED   0x0080      /* Channel Disconnect */
 #define LIBSSH2_POLLFD_LISTENER_CLOSED  0x0080      /* Listener Disconnect */
 
+#define HAVE_LIBSSH2_SESSION_BLOCK_DIRECTION
+/* Block Direction Types */
+#define LIBSSH2_SESSION_BLOCK_INBOUND                  0x0001
+#define LIBSSH2_SESSION_BLOCK_OUTBOUND                 0x0002
+
 /* Hash Types */
 #define LIBSSH2_HOSTKEY_HASH_MD5                            1
 #define LIBSSH2_HOSTKEY_HASH_SHA1                           2
@@ -324,6 +329,7 @@ LIBSSH2_API int libssh2_session_method_pref(LIBSSH2_SESSION *session, int method
 LIBSSH2_API const char *libssh2_session_methods(LIBSSH2_SESSION *session, int method_type);
 LIBSSH2_API int libssh2_session_last_error(LIBSSH2_SESSION *session, char **errmsg, int *errmsg_len, int want_buf);
 LIBSSH2_API int libssh2_session_last_errno(LIBSSH2_SESSION *session);
+LIBSSH2_API int libssh2_session_block_directions(LIBSSH2_SESSION *session);
 
 LIBSSH2_API int libssh2_session_flag(LIBSSH2_SESSION *session, int flag, int value);
 

src/kex.c

@@ -1674,7 +1674,7 @@ libssh2_kex_agree_methods(LIBSSH2_SESSION * session, unsigned char *data,
  * Returns 0 on success, non-zero on failure
  */
 int
-libssh2_kex_exchange(LIBSSH2_SESSION * session, int reexchange, /* session->flags |= SERVER */
+libssh2_kex_exchange(LIBSSH2_SESSION * session, int reexchange,
                      key_exchange_state_t * key_state)
 {
     int rc = 0;

src/libssh2_priv.h

@@ -705,6 +705,7 @@ struct _LIBSSH2_SESSION
     int socket_fd;
     int socket_block;
     int socket_state;
+    int socket_block_directions;
 
     /* Error tracking */
     char *err_msg;

src/packet.c

@@ -665,6 +665,8 @@ libssh2_packet_add(LIBSSH2_SESSION * session, unsigned char *data,
                                                                datalen - 13,
                                                                0);
                     if (rc == PACKET_EAGAIN) {
+                        session->socket_block_directions =
+                            LIBSSH2_SESSION_BLOCK_OUTBOUND;
                         return PACKET_EAGAIN;
                     }
                     session->packAdd_state = libssh2_NB_state_idle;
@@ -817,6 +819,8 @@ libssh2_packet_add(LIBSSH2_SESSION * session, unsigned char *data,
                                                    &session->
                                                    packAdd_Qlstn_state);
                 if (rc == PACKET_EAGAIN) {
+                    session->socket_block_directions =
+                        LIBSSH2_SESSION_BLOCK_OUTBOUND;
                     return PACKET_EAGAIN;
                 }
 
@@ -833,6 +837,8 @@ libssh2_packet_add(LIBSSH2_SESSION * session, unsigned char *data,
                 rc = libssh2_packet_x11_open(session, data, datalen,
                                              &session->packAdd_x11open_state);
                 if (rc == PACKET_EAGAIN) {
+                    session->socket_block_directions =
+                        LIBSSH2_SESSION_BLOCK_OUTBOUND;
                     return PACKET_EAGAIN;
                 }
 

src/session.c

@@ -133,6 +133,8 @@ libssh2_banner_receive(LIBSSH2_SESSION * session)
             }
 #endif /* WIN32 */
             if (errno == EAGAIN) {
+                session->socket_block_directions =
+                    LIBSSH2_SESSION_BLOCK_INBOUND;
                 session->banner_TxRx_total_send = banner_len;
                 return PACKET_EAGAIN;
             }
@@ -235,6 +237,8 @@ libssh2_banner_send(LIBSSH2_SESSION * session)
     if (ret != (banner_len - session->banner_TxRx_total_send)) {
         if ((ret > 0) || ((ret == -1) && (errno == EAGAIN))) {
             /* the whole packet could not be sent, save the what was */
+            session->socket_block_directions =
+                LIBSSH2_SESSION_BLOCK_OUTBOUND;
             session->banner_TxRx_total_send += ret;
             return PACKET_EAGAIN;
         }
@@ -1536,4 +1540,15 @@ libssh2_poll(LIBSSH2_POLLFD * fds, unsigned int nfds, long timeout)
     return active_fds;
 }
 
+/* {{{ libssh2_session_block_direction
+ * Get blocked direction when a function returns LIBSSH2_ERROR_EAGAIN
+ * Returns LIBSSH2_SOCKET_BLOCK_INBOUND if recv() blocked
+ * or LIBSSH2_SOCKET_BLOCK_OUTBOUND if send() blocked
+ */
+LIBSSH2_API int
+libssh2_session_block_directions(LIBSSH2_SESSION *session)
+{
+    return session->socket_block_directions;
+}
+
 /* }}} */

src/transport.c

@@ -385,6 +385,8 @@ libssh2_packet_read(LIBSSH2_SESSION * session)
                 }
 #endif /* WIN32 */
                 if ((nread < 0) && (errno == EAGAIN)) {
+                    session->socket_block_directions =
+                        LIBSSH2_SESSION_BLOCK_INBOUND;
                     return PACKET_EAGAIN;
                 }
                 return PACKET_FAIL;
@@ -564,14 +566,14 @@ libssh2_packet_read(LIBSSH2_SESSION * session)
 
                 if (session->packAdd_state != libssh2_NB_state_idle)
                 {
-                    /* fullpacket only returns PACKET_EAGAIN if 
+                    /* fullpacket only returns PACKET_EAGAIN if
                      * libssh2_packet_add returns PACKET_EAGAIN. If that
                      * returns PACKET_EAGAIN but the packAdd_state is idle,
                      * then the packet has been added to the brigade, but some
-                     * immediate action that was taken based on the packet 
+                     * immediate action that was taken based on the packet
-                     * type (such as key re-exchange) is not yet complete. 
+                     * type (such as key re-exchange) is not yet complete.
                      * Clear the way for a new packet to be read in.
-                     */ 
+                     */
                     session->readPack_encrypted = encrypted;
                     session->readPack_state = libssh2_NB_state_jump1;
                 }
@@ -634,6 +636,7 @@ send_existing(LIBSSH2_SESSION * session, unsigned char *data,
             /* send failure! */
             return PACKET_FAIL;
         }
+        session->socket_block_directions = LIBSSH2_SESSION_BLOCK_OUTBOUND;
         return PACKET_EAGAIN;
     }
 
@@ -786,6 +789,7 @@ libssh2_packet_write(LIBSSH2_SESSION * session, unsigned char *data,
     if (ret != total_length) {
         if ((ret > 0) || ((ret == -1) && (errno == EAGAIN))) {
             /* the whole packet could not be sent, save the rest */
+            session->socket_block_directions = LIBSSH2_SESSION_BLOCK_OUTBOUND;
             p->odata = orgdata;
             p->olen = orgdata_len;
             p->osent = (ret == -1) ? 0 : ret;