add CURLINFO_SCHEME, CURLINFO_PROTOCOL, and %{scheme}

Adds access to the effectively used protocol/scheme to both libcurl and
curl, both in string and numeric (CURLPROTO_*) form.

Note that the string form will be uppercase, as it is just the internal
string.

As these strings are declared internally as const, and all other strings
returned by curl_easy_getinfo() are de-facto const as well, string
handling in getinfo.c got const-ified.

Closes #1137

10 files changed, 150 insertions, 4 deletions

diff --git a/docs/curl.1 b/docs/curl.1
index d2765ab19..51680315f 100644
--- a/docs/curl.1
+++ b/docs/curl.1
@@ -2068,6 +2068,9 @@ IPv4 or IPv6 (Added in 7.29.0)
 .B remote_port
 The remote port number of the most recently done connection (Added in 7.29.0)
 .TP
+.B scheme
+The URL scheme (sometimes called protocol) that was effectively used (Added in 7.52.0)
+.TP
 .B size_download
 The total amount of bytes that were downloaded.
 .TP
diff --git a/docs/libcurl/curl_easy_getinfo.3 b/docs/libcurl/curl_easy_getinfo.3
index 4f36561ac..fabc7e92f 100644
--- a/docs/libcurl/curl_easy_getinfo.3
+++ b/docs/libcurl/curl_easy_getinfo.3
@@ -183,6 +183,12 @@ See \fICURLINFO_RTSP_SERVER_CSEQ(3)\fP
 .IP CURLINFO_RTSP_CSEQ_RECV
 RTSP CSeq last received.
 See \fICURLINFO_RTSP_CSEQ_RECV(3)\fP
+.IP CURLINFO_PROTOCOL
+The protocol used for the connection. (Added in 7.52.0)
+See \fICURLINFO_PROTOCOL(3)\fP
+.IP CURLINFO_SCHEME
+The scheme used for the connection. (Added in 7.52.0)
+See \fICURLINFO_SCHEME(3)\fP
 .SH TIMES
 .nf
 An overview of the six time values available from curl_easy_getinfo()
diff --git a/docs/libcurl/opts/CURLINFO_PROTOCOL.3 b/docs/libcurl/opts/CURLINFO_PROTOCOL.3
new file mode 100644
index 000000000..b82111876
--- /dev/null
+++ b/docs/libcurl/opts/CURLINFO_PROTOCOL.3
@@ -0,0 +1,55 @@
+.\" **************************************************************************
+.\" *                                  _   _ ____  _
+.\" *  Project                     ___| | | |  _ \| |
+.\" *                             / __| | | | |_) | |
+.\" *                            | (__| |_| |  _ <| |___
+.\" *                             \___|\___/|_| \_\_____|
+.\" *
+.\" * Copyright (C) 1998 - 2016, 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
+.\" * are also available at https://curl.haxx.se/docs/copyright.html.
+.\" *
+.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+.\" * copies of the Software, and permit persons to whom the Software is
+.\" * furnished to do so, under the terms of the COPYING file.
+.\" *
+.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+.\" * KIND, either express or implied.
+.\" *
+.\" **************************************************************************
+.\"
+.TH CURLINFO_PROTOCOL 3 "23 November 2016" "libcurl 7.52.0" "curl_easy_getinfo options"
+.SH NAME
+CURLINFO_PROTOCOL \- get the protocol used in the connection
+.SH SYNOPSIS
+#include <curl/curl.h>
+
+CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_PROTOCOL, long *p);
+.SH DESCRIPTION
+Pass a pointer to a long to receive the version used in the last http connection.
+The returned value will be one of the CURLPROTO_* values.
+.SH PROTOCOLS
+All
+.SH EXAMPLE
+.nf
+CURL *curl = curl_easy_init();
+if(curl) {
+  CURLcode res;
+  curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
+  res = curl_easy_perform(curl);
+  if(res == CURLE_OK) {
+    long protocol;
+    curl_easy_getinfo(curl, CURLINFO_PROTOCOL, &protocol);
+  }
+  curl_easy_cleanup(curl);
+}
+.fi
+.SH AVAILABILITY
+Added in 7.52.0
+.SH RETURN VALUE
+Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
+.SH "SEE ALSO"
+.BR CURLINFO_RESPONSE_CODE "(3), "
+.BR curl_easy_getinfo "(3), " curl_easy_setopt "(3), "
diff --git a/docs/libcurl/opts/CURLINFO_SCHEME.3 b/docs/libcurl/opts/CURLINFO_SCHEME.3
new file mode 100644
index 000000000..78c3d6886
--- /dev/null
+++ b/docs/libcurl/opts/CURLINFO_SCHEME.3
@@ -0,0 +1,59 @@
+.\" **************************************************************************
+.\" *                                  _   _ ____  _
+.\" *  Project                     ___| | | |  _ \| |
+.\" *                             / __| | | | |_) | |
+.\" *                            | (__| |_| |  _ <| |___
+.\" *                             \___|\___/|_| \_\_____|
+.\" *
+.\" * Copyright (C) 1998 - 2016, 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
+.\" * are also available at https://curl.haxx.se/docs/copyright.html.
+.\" *
+.\" * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+.\" * copies of the Software, and permit persons to whom the Software is
+.\" * furnished to do so, under the terms of the COPYING file.
+.\" *
+.\" * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+.\" * KIND, either express or implied.
+.\" *
+.\" **************************************************************************
+.\"
+.TH CURLINFO_SCHEME 3 "23 November 2016" "libcurl 7.52.0" "curl_easy_getinfo options"
+.SH NAME
+CURLINFO_SCHEME \- get the URL scheme (sometimes called protocol) used in the connection
+.SH SYNOPSIS
+#include <curl/curl.h>
+
+CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_SCHEME, long *p);
+.SH DESCRIPTION
+Pass a pointer to a char pointer to receive the pointer to a zero-terminated
+string holding the URL scheme used for the most recent connection done with this
+\fBcurl\fP handle.
+
+The \fBid\fP pointer will be NULL or pointing to private read-only memory you
+MUST NOT free or modify.
+.SH PROTOCOLS
+All
+.SH EXAMPLE
+.nf
+CURL *curl = curl_easy_init();
+if(curl) {
+  CURLcode res;
+  curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
+  res = curl_easy_perform(curl);
+  if(res == CURLE_OK) {
+    char * scheme;
+    curl_easy_getinfo(curl, CURLINFO_SCHEME, &scheme);
+  }
+  curl_easy_cleanup(curl);
+}
+.fi
+.SH AVAILABILITY
+Added in 7.52.0
+.SH RETURN VALUE
+Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
+.SH "SEE ALSO"
+.BR CURLINFO_RESPONSE_CODE "(3), "
+.BR curl_easy_getinfo "(3), " curl_easy_setopt "(3), "
diff --git a/docs/libcurl/symbols-in-versions b/docs/libcurl/symbols-in-versions
index 1d58d51c1..0831775be 100644
--- a/docs/libcurl/symbols-in-versions
+++ b/docs/libcurl/symbols-in-versions
@@ -239,6 +239,7 @@ CURLINFO_PRETRANSFER_TIME       7.4.1
 CURLINFO_PRIMARY_IP             7.19.0
 CURLINFO_PRIMARY_PORT           7.21.0
 CURLINFO_PRIVATE                7.10.3
+CURLINFO_PROTOCOL               7.52.0
 CURLINFO_PROXYAUTH_AVAIL        7.10.8
 CURLINFO_PROXY_SSL_VERIFYRESULT 7.52.0
 CURLINFO_REDIRECT_COUNT         7.9.7
@@ -250,6 +251,7 @@ CURLINFO_RTSP_CLIENT_CSEQ       7.20.0
 CURLINFO_RTSP_CSEQ_RECV         7.20.0
 CURLINFO_RTSP_SERVER_CSEQ       7.20.0
 CURLINFO_RTSP_SESSION_ID        7.20.0
+CURLINFO_SCHEME                 7.52.0
 CURLINFO_SIZE_DOWNLOAD          7.4.1
 CURLINFO_SIZE_UPLOAD            7.4.1
 CURLINFO_SLIST                  7.12.3
diff --git a/include/curl/curl.h b/include/curl/curl.h
index bf7114897..df2914e2d 100644
--- a/include/curl/curl.h
+++ b/include/curl/curl.h
@@ -2277,9 +2277,11 @@ typedef enum {
   CURLINFO_TLS_SSL_PTR      = CURLINFO_SLIST  + 45,
   CURLINFO_HTTP_VERSION     = CURLINFO_LONG   + 46,
   CURLINFO_PROXY_SSL_VERIFYRESULT = CURLINFO_LONG + 47,
+  CURLINFO_PROTOCOL         = CURLINFO_LONG   + 48,
+  CURLINFO_SCHEME           = CURLINFO_STRING + 49,
   /* Fill in new entries below here! */
 
-  CURLINFO_LASTONE          = 47
+  CURLINFO_LASTONE          = 49
 } CURLINFO;
 
 /* CURLINFO_RESPONSE_CODE is the new name for the option previously known as
diff --git a/lib/connect.c b/lib/connect.c
index 40252541f..c78d3da36 100644
--- a/lib/connect.c
+++ b/lib/connect.c
@@ -601,6 +601,8 @@ void Curl_persistconninfo(struct connectdata *conn)
 {
   memcpy(conn->data->info.conn_primary_ip, conn->primary_ip, MAX_IPADR_LEN);
   memcpy(conn->data->info.conn_local_ip, conn->local_ip, MAX_IPADR_LEN);
+  conn->data->info.conn_scheme = conn->handler->scheme;
+  conn->data->info.conn_protocol = conn->handler->protocol;
   conn->data->info.conn_primary_port = conn->primary_port;
   conn->data->info.conn_local_port = conn->local_port;
 }
diff --git a/lib/getinfo.c b/lib/getinfo.c
index 7dcc71d33..4459a486b 100644
--- a/lib/getinfo.c
+++ b/lib/getinfo.c
@@ -86,7 +86,7 @@ CURLcode Curl_initinfo(struct Curl_easy *data)
 }
 
 static CURLcode getinfo_char(struct Curl_easy *data, CURLINFO info,
-                             char **param_charp)
+                             const char **param_charp)
 {
   switch(info) {
   case CURLINFO_EFFECTIVE_URL:
@@ -123,6 +123,9 @@ static CURLcode getinfo_char(struct Curl_easy *data, CURLINFO info,
   case CURLINFO_RTSP_SESSION_ID:
     *param_charp = data->set.str[STRING_RTSP_SESSION_ID];
     break;
+  case CURLINFO_SCHEME:
+    *param_charp = data->info.conn_scheme;
+    break;
 
   default:
     return CURLE_UNKNOWN_OPTION;
@@ -229,6 +232,9 @@ static CURLcode getinfo_long(struct Curl_easy *data, CURLINFO info,
       break;
     }
     break;
+  case CURLINFO_PROTOCOL:
+    *param_longp = data->info.conn_protocol;
+    break;
 
   default:
     return CURLE_UNKNOWN_OPTION;
@@ -385,7 +391,7 @@ CURLcode Curl_getinfo(struct Curl_easy *data, CURLINFO info, ...)
   va_list arg;
   long *param_longp = NULL;
   double *param_doublep = NULL;
-  char **param_charp = NULL;
+  const char **param_charp = NULL;
   struct curl_slist **param_slistp = NULL;
   curl_socket_t *param_socketp = NULL;
   int type;
@@ -399,7 +405,7 @@ CURLcode Curl_getinfo(struct Curl_easy *data, CURLINFO info, ...)
   type = CURLINFO_TYPEMASK & (int)info;
   switch(type) {
   case CURLINFO_STRING:
-    param_charp = va_arg(arg, char **);
+    param_charp = va_arg(arg, const char **);
     if(param_charp)
       result = getinfo_char(data, info, param_charp);
     break;
diff --git a/lib/urldata.h b/lib/urldata.h
index 6e548285b..05f600319 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -1174,6 +1174,9 @@ struct PureInfo {
   char conn_local_ip[MAX_IPADR_LEN];
   long conn_local_port;
 
+  const char *conn_scheme;
+  unsigned int conn_protocol;
+
   struct curl_certinfo certs; /* info about the certs, only populated in
                                  OpenSSL builds. Asked for with
                                  CURLOPT_CERTINFO / CURLINFO_CERTINFO */
diff --git a/src/tool_writeout.c b/src/tool_writeout.c
index dfe86471e..3737df801 100644
--- a/src/tool_writeout.c
+++ b/src/tool_writeout.c
@@ -59,6 +59,7 @@ typedef enum {
   VAR_LOCAL_IP,
   VAR_LOCAL_PORT,
   VAR_HTTP_VERSION,
+  VAR_SCHEME,
   VAR_NUM_OF_VARS /* must be the last */
 } replaceid;
 
@@ -99,6 +100,7 @@ static const struct variable replacements[]={
   {"local_ip", VAR_LOCAL_IP},
   {"local_port", VAR_LOCAL_PORT},
   {"http_version", VAR_HTTP_VERSION},
+  {"scheme", VAR_SCHEME},
   {NULL, VAR_NONE}
 };
 
@@ -308,6 +310,12 @@ void ourWriteOut(CURL *curl, struct OutStruct *outs, const char *writeinfo)
                   fprintf(stream, version);
                 }
                 break;
+              case VAR_SCHEME:
+                if(CURLE_OK ==
+                   curl_easy_getinfo(curl, CURLINFO_SCHEME,
+                                     &stringp))
+                  fprintf(stream, "%s", stringp);
+                break;
               default:
                 break;
               }