From a2f93579b704fb1c2b56cf93e9a4da84e0cecf05 Mon Sep 17 00:00:00 2001
From: Eshan Kelkar <eshankelkar@galorithm.com>
Date: Sat, 24 May 2025 01:56:40 +0530
Subject: [PATCH] libssh: Use sftp_aio instead of sftp_async for sftp_recv

This commit replaces the usage of the old deprecated
sftp_async API with the new sftp_aio API for remote
file reading.

Signed-off-by: Eshan Kelkar <eshankelkar@galorithm.com>
---
 lib/vssh/libssh.c | 23 +++++++++++++++++++++++
 lib/vssh/ssh.h    |  5 ++++-
 2 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/lib/vssh/libssh.c b/lib/vssh/libssh.c
index d8e03e7ab1..e5b8de6017 100644
--- a/lib/vssh/libssh.c
+++ b/lib/vssh/libssh.c
@@ -1464,6 +1464,11 @@ static int myssh_in_SFTP_SHUTDOWN(struct Curl_easy *data,
     sftp_aio_free(sshc->sftp_send_aio);
     sshc->sftp_send_aio = NULL;
   }
+
+  if(sshc->sftp_recv_aio) {
+    sftp_aio_free(sshc->sftp_recv_aio);
+    sshc->sftp_recv_aio = NULL;
+  }
 #endif
 
   if(sshc->sftp_file) {
@@ -3101,16 +3106,28 @@ static CURLcode sftp_recv(struct Curl_easy *data, int sockindex,
 
   switch(sshc->sftp_recv_state) {
     case 0:
+#if LIBSSH_VERSION_INT > SSH_VERSION_INT(0, 11, 0)
+      if(sftp_aio_begin_read(sshc->sftp_file, len,
+                             &sshc->sftp_recv_aio) == SSH_ERROR) {
+        return CURLE_RECV_ERROR;
+      }
+#else
       sshc->sftp_file_index =
         sftp_async_read_begin(sshc->sftp_file, (uint32_t)len);
       if(sshc->sftp_file_index < 0)
         return CURLE_RECV_ERROR;
+#endif
 
       FALLTHROUGH();
     case 1:
       sshc->sftp_recv_state = 1;
+
+#if LIBSSH_VERSION_INT > SSH_VERSION_INT(0, 11, 0)
+      nread = sftp_aio_wait_read(&sshc->sftp_recv_aio, mem, len);
+#else
       nread = sftp_async_read(sshc->sftp_file, mem, (uint32_t)len,
                               (uint32_t)sshc->sftp_file_index);
+#endif
 
       myssh_block2waitfor(conn, sshc, (nread == SSH_AGAIN));
 
@@ -3119,6 +3136,12 @@ static CURLcode sftp_recv(struct Curl_easy *data, int sockindex,
       else if(nread < 0)
         return CURLE_RECV_ERROR;
 
+      /*
+       * sftp_aio_wait_read() would free sftp_recv_aio and
+       * assign it NULL in all cases except when it returns
+       * SSH_AGAIN.
+       */
+
       sshc->sftp_recv_state = 0;
       *pnread = (size_t)nread;
       return CURLE_OK;
diff --git a/lib/vssh/ssh.h b/lib/vssh/ssh.h
index 89bc051c7c..3a29927e8c 100644
--- a/lib/vssh/ssh.h
+++ b/lib/vssh/ssh.h
@@ -180,10 +180,13 @@ struct ssh_conn {
 
   unsigned sftp_recv_state; /* 0 or 1 */
 #if LIBSSH_VERSION_INT > SSH_VERSION_INT(0, 11, 0)
+  sftp_aio sftp_recv_aio;
+
   sftp_aio sftp_send_aio;
   unsigned sftp_send_state; /* 0 or 1 */
-#endif
+#else
   int sftp_file_index; /* for async read */
+#endif
   sftp_attributes readdir_attrs; /* used by the SFTP readdir actions */
   sftp_attributes readdir_link_attrs; /* used by the SFTP readdir actions */
   sftp_attributes quote_attrs; /* used by the SFTP_QUOTE state */