tool_operate: only set SSH related libcurl options for SSH URLs

For example, this avoids trying to find and set the known_hosts file (or
warn for its absence) if SFTP or SCP are not used.

Closes #8040

src/tool_libinfo.c

@@ -36,6 +36,39 @@
 curl_version_info_data *curlinfo = NULL;
 long built_in_protos = 0;
 
+static struct proto_name_pattern {
+  const char *proto_name;
+  long        proto_pattern;
+} const possibly_built_in[] = {
+  { "dict",   CURLPROTO_DICT   },
+  { "file",   CURLPROTO_FILE   },
+  { "ftp",    CURLPROTO_FTP    },
+  { "ftps",   CURLPROTO_FTPS   },
+  { "gopher", CURLPROTO_GOPHER },
+  { "gophers",CURLPROTO_GOPHERS},
+  { "http",   CURLPROTO_HTTP   },
+  { "https",  CURLPROTO_HTTPS  },
+  { "imap",   CURLPROTO_IMAP   },
+  { "imaps",  CURLPROTO_IMAPS  },
+  { "ldap",   CURLPROTO_LDAP   },
+  { "ldaps",  CURLPROTO_LDAPS  },
+  { "mqtt",   CURLPROTO_MQTT   },
+  { "pop3",   CURLPROTO_POP3   },
+  { "pop3s",  CURLPROTO_POP3S  },
+  { "rtmp",   CURLPROTO_RTMP   },
+  { "rtmps",  CURLPROTO_RTMPS  },
+  { "rtsp",   CURLPROTO_RTSP   },
+  { "scp",    CURLPROTO_SCP    },
+  { "sftp",   CURLPROTO_SFTP   },
+  { "smb",    CURLPROTO_SMB    },
+  { "smbs",   CURLPROTO_SMBS   },
+  { "smtp",   CURLPROTO_SMTP   },
+  { "smtps",  CURLPROTO_SMTPS  },
+  { "telnet", CURLPROTO_TELNET },
+  { "tftp",   CURLPROTO_TFTP   },
+  {  NULL,    0                }
+};
+
 /*
  * libcurl_info_init: retrieves run-time information about libcurl,
  * setting a global pointer 'curlinfo' to libcurl's run-time info
@@ -46,39 +79,6 @@ long built_in_protos = 0;
 
 CURLcode get_libcurl_info(void)
 {
-  static struct proto_name_pattern {
-    const char *proto_name;
-    long        proto_pattern;
-  } const possibly_built_in[] = {
-    { "dict",   CURLPROTO_DICT   },
-    { "file",   CURLPROTO_FILE   },
-    { "ftp",    CURLPROTO_FTP    },
-    { "ftps",   CURLPROTO_FTPS   },
-    { "gopher", CURLPROTO_GOPHER },
-    { "gophers",CURLPROTO_GOPHERS},
-    { "http",   CURLPROTO_HTTP   },
-    { "https",  CURLPROTO_HTTPS  },
-    { "imap",   CURLPROTO_IMAP   },
-    { "imaps",  CURLPROTO_IMAPS  },
-    { "ldap",   CURLPROTO_LDAP   },
-    { "ldaps",  CURLPROTO_LDAPS  },
-    { "mqtt",   CURLPROTO_MQTT   },
-    { "pop3",   CURLPROTO_POP3   },
-    { "pop3s",  CURLPROTO_POP3S  },
-    { "rtmp",   CURLPROTO_RTMP   },
-    { "rtmps",  CURLPROTO_RTMPS  },
-    { "rtsp",   CURLPROTO_RTSP   },
-    { "scp",    CURLPROTO_SCP    },
-    { "sftp",   CURLPROTO_SFTP   },
-    { "smb",    CURLPROTO_SMB    },
-    { "smbs",   CURLPROTO_SMBS   },
-    { "smtp",   CURLPROTO_SMTP   },
-    { "smtps",  CURLPROTO_SMTPS  },
-    { "telnet", CURLPROTO_TELNET },
-    { "tftp",   CURLPROTO_TFTP   },
-    {  NULL,    0                }
-  };
-
   const char *const *proto;
 
   /* Pointer to libcurl's run-time version information */
@@ -102,3 +102,16 @@ CURLcode get_libcurl_info(void)
 
   return CURLE_OK;
 }
+
+/*
+ * scheme2protocol() returns the protocol bit for the specified URL scheme
+ */
+long scheme2protocol(const char *scheme)
+{
+  struct proto_name_pattern const *p;
+  for(p = possibly_built_in; p->proto_name; p++) {
+    if(curl_strequal(scheme, p->proto_name))
+      return p->proto_pattern;
+  }
+  return 0;
+}

src/tool_libinfo.h

@@ -7,7 +7,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -29,5 +29,6 @@ extern curl_version_info_data *curlinfo;
 extern long built_in_protos;
 
 CURLcode get_libcurl_info(void);
+long scheme2protocol(const char *scheme);
 
 #endif /* HEADER_CURL_TOOL_LIBINFO_H */

src/tool_operate.c

@@ -661,6 +661,29 @@ static void single_transfer_cleanup(struct OperationConfig *config)
   }
 }
 
+/*
+ * Return the proto bit for the scheme used in the given URL
+ */
+static long url_proto(char *url)
+{
+  CURLU *uh = curl_url();
+  long proto = 0;
+  if(url) {
+    if(!curl_url_set(uh, CURLUPART_URL, url,
+                     CURLU_GUESS_SCHEME | CURLU_NON_SUPPORT_SCHEME)) {
+      char *schemep = NULL;
+      if(!curl_url_get(uh, CURLUPART_SCHEME, &schemep,
+                       CURLU_DEFAULT_SCHEME) &&
+         schemep) {
+        proto = scheme2protocol(schemep);
+        curl_free(schemep);
+      }
+    }
+    curl_url_cleanup(uh);
+  }
+  return proto;
+}
+
 /* create the next (singular) transfer */
 
 static CURLcode single_transfer(struct GlobalConfig *global,
@@ -801,6 +824,7 @@ static CURLcode single_transfer(struct GlobalConfig *global,
         struct OutStruct *etag_save;
         struct HdrCbData *hdrcbdata = NULL;
         struct OutStruct etag_first;
+        long use_proto;
         CURL *curl;
 
         /* --etag-save */
@@ -1194,6 +1218,15 @@ static CURLcode single_transfer(struct GlobalConfig *global,
         if(result)
           break;
 
+        /* here */
+        use_proto = url_proto(per->this_url);
+#if 0
+        if(!(use_proto & built_in_protos)) {
+          warnf(global, "URL is '%s' but no support for the scheme\n",
+                per->this_url);
+        }
+#endif
+
         if(!config->tcp_nodelay)
           my_setopt(curl, CURLOPT_TCP_NODELAY, 0L);
 
@@ -1410,7 +1443,7 @@ static CURLcode single_transfer(struct GlobalConfig *global,
         my_setopt_str(curl, CURLOPT_KEYPASSWD, config->key_passwd);
         my_setopt_str(curl, CURLOPT_PROXY_KEYPASSWD, config->proxy_key_passwd);
 
-        if(built_in_protos & (CURLPROTO_SCP|CURLPROTO_SFTP)) {
+        if(use_proto & (CURLPROTO_SCP|CURLPROTO_SFTP)) {
 
           /* SSH and SSL private key uses same command-line option */
           /* new in libcurl 7.16.1 */
@@ -1681,7 +1714,7 @@ static CURLcode single_transfer(struct GlobalConfig *global,
         if(config->path_as_is)
           my_setopt(curl, CURLOPT_PATH_AS_IS, 1L);
 
-        if((built_in_protos & (CURLPROTO_SCP|CURLPROTO_SFTP)) &&
+        if((use_proto & (CURLPROTO_SCP|CURLPROTO_SFTP)) &&
            !config->insecure_ok) {
           char *home = homedir(NULL);
           if(home) {