Add sftp_symlink function.

include/libssh/sftp.h

@@ -592,6 +592,19 @@ int sftp_chmod(SFTP_SESSION *sftp, const char *file, mode_t mode);
  */
 int sftp_utimes(SFTP_SESSION *sftp, const char *file, const struct timeval *times);
 
+/**
+ * @brief Create a symbolic link.
+ *
+ * @param  sftp         The sftp session handle.
+ *
+ * @param  target       Specifies the target of the symlink.
+ *
+ * @param  dest         Specifies the path name of the symlink to be created.
+ *
+ * @return              0 on success, < 0 on error with ssh and sftp error set.
+ */
+int sftp_symlink(SFTP_SESSION *sftp, const char *target, const char *dest);
+
 /**
  * @brief Canonicalize a sftp path.
  *

libssh/sftp.c

@@ -2212,6 +2212,89 @@ int sftp_utimes(SFTP_SESSION *sftp, const char *file,
   return sftp_setstat(sftp, file, &attr);
 }
 
+int sftp_symlink(SFTP_SESSION *sftp, const char *target, const char *dest) {
+  STATUS_MESSAGE *status = NULL;
+  SFTP_MESSAGE *msg = NULL;
+  ssh_string target_s;
+  ssh_string dest_s;
+  ssh_buffer buffer;
+  u32 id;
+
+  if (sftp == NULL || target == NULL || dest == NULL) {
+    return -1;
+  }
+
+  buffer = buffer_new();
+  if (buffer == NULL) {
+    return -1;
+  }
+
+  target_s = string_from_char(target);
+  if (target_s == NULL) {
+    buffer_free(buffer);
+    return -1;
+  }
+
+  dest_s = string_from_char(dest);
+  if (dest_s == NULL) {
+    string_free(target_s);
+    buffer_free(buffer);
+    return -1;
+  }
+
+  id = sftp_get_new_id(sftp);
+  if (buffer_add_u32(buffer, id) < 0 ||
+      buffer_add_ssh_string(buffer, target_s) < 0 ||
+      buffer_add_ssh_string(buffer, dest_s) < 0 ||
+      sftp_packet_write(sftp, SSH_FXP_SYMLINK, buffer) < 0) {
+    buffer_free(buffer);
+    string_free(dest_s);
+    string_free(target_s);
+    return -1;
+  }
+  buffer_free(buffer);
+  string_free(dest_s);
+  string_free(target_s);
+
+  while (msg == NULL) {
+    if (sftp_read_and_dispatch(sftp) < 0) {
+      return -1;
+    }
+    msg = sftp_dequeue(sftp, id);
+  }
+
+  /* By specification, this command only returns SSH_FXP_STATUS */
+  if (msg->packet_type == SSH_FXP_STATUS) {
+    status = parse_status_msg(msg);
+    sftp_message_free(msg);
+    if (status == NULL) {
+      return -1;
+    }
+    sftp_set_error(sftp, status->status);
+    switch (status->status) {
+      case SSH_FX_OK:
+        status_msg_free(status);
+        return 0;
+      default:
+        break;
+    }
+    /*
+     * The status should be SSH_FX_OK if the command was successful, if it
+     * didn't, then there was an error
+     */
+    ssh_set_error(sftp->session, SSH_REQUEST_DENIED,
+        "SFTP server: %s", status->errormsg);
+    status_msg_free(status);
+    return -1;
+  } else {
+    ssh_set_error(sftp->session, SSH_FATAL,
+        "Received message %d when attempting to set stats", msg->packet_type);
+    sftp_message_free(msg);
+  }
+
+  return -1;
+}
+
 /* another code written by Nick */
 char *sftp_canonicalize_path(SFTP_SESSION *sftp, const char *path) {
   STATUS_MESSAGE *status = NULL;