host names: allow trailing dot in name resolve, then strip it

Delays stripping of trailing dots to after resolving the hostname.

Fixes #3022
Closes #3222

2 files changed, 55 insertions, 28 deletions

diff --git a/lib/url.c b/lib/url.c
index 0ebf0a07a..3625bcdce 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -127,7 +127,7 @@ bool curl_win32_idn_to_ascii(const char *in, char **out);
 #include "memdebug.h"
 
 static void conn_free(struct connectdata *conn);
-static void free_fixed_hostname(struct hostname *host);
+static void free_idnconverted_hostname(struct hostname *host);
 static unsigned int get_protocol_family(unsigned int protocol);
 
 /* Some parts of the code (e.g. chunked encoding) assume this buffer has at
@@ -708,6 +708,7 @@ static void conn_free(struct connectdata *conn)
   Curl_safefree(conn->trailer);
   Curl_safefree(conn->host.rawalloc); /* host name buffer */
   Curl_safefree(conn->conn_to_host.rawalloc); /* host name buffer */
+  Curl_safefree(conn->hostname_resolve);
   Curl_safefree(conn->secondaryhostname);
   Curl_safefree(conn->http_proxy.host.rawalloc); /* http proxy name buffer */
   Curl_safefree(conn->socks_proxy.host.rawalloc); /* socks proxy name buffer */
@@ -788,10 +789,10 @@ CURLcode Curl_disconnect(struct Curl_easy *data,
   infof(data, "Closing connection %ld\n", conn->connection_id);
   Curl_conncache_remove_conn(conn, TRUE);
 
-  free_fixed_hostname(&conn->host);
-  free_fixed_hostname(&conn->conn_to_host);
-  free_fixed_hostname(&conn->http_proxy.host);
-  free_fixed_hostname(&conn->socks_proxy.host);
+  free_idnconverted_hostname(&conn->host);
+  free_idnconverted_hostname(&conn->conn_to_host);
+  free_idnconverted_hostname(&conn->http_proxy.host);
+  free_idnconverted_hostname(&conn->socks_proxy.host);
 
   DEBUGASSERT(conn->data == data);
   /* this assumes that the pointer is still there after the connection was
@@ -1679,11 +1680,23 @@ static bool is_ASCII_name(const char *hostname)
 }
 
 /*
- * Perform any necessary IDN conversion of hostname
+ * Strip single trailing dot in the hostname,
+ * primarily for SNI and http host header.
  */
-static CURLcode fix_hostname(struct connectdata *conn, struct hostname *host)
+static void strip_trailing_dot(struct hostname *host)
 {
   size_t len;
+  len = strlen(host->name);
+  if(len && (host->name[len-1] == '.'))
+    host->name[len-1] = 0;
+}
+
+/*
+ * Perform any necessary IDN conversion of hostname
+ */
+static CURLcode idnconvert_hostname(struct connectdata *conn,
+                                    struct hostname *host)
+{
   struct Curl_easy *data = conn->data;
 
 #ifndef USE_LIBIDN2
@@ -1696,12 +1709,6 @@ static CURLcode fix_hostname(struct connectdata *conn, struct hostname *host)
   /* set the name we use to display the host name */
   host->dispname = host->name;
 
-  len = strlen(host->name);
-  if(len && (host->name[len-1] == '.'))
-    /* strip off a single trailing dot if present, primarily for SNI but
-       there's no use for it */
-    host->name[len-1] = 0;
-
   /* Check name for non-ASCII and convert hostname to ACE form if we can */
   if(!is_ASCII_name(host->name)) {
 #ifdef USE_LIBIDN2
@@ -1756,9 +1763,9 @@ static CURLcode fix_hostname(struct connectdata *conn, struct hostname *host)
 }
 
 /*
- * Frees data allocated by fix_hostname()
+ * Frees data allocated by idnconvert_hostname()
  */
-static void free_fixed_hostname(struct hostname *host)
+static void free_idnconverted_hostname(struct hostname *host)
 {
 #if defined(USE_LIBIDN2)
   if(host->encalloc) {
@@ -3373,7 +3380,7 @@ static CURLcode resolve_server(struct Curl_easy *data,
    *************************************************************/
   if(conn->bits.reuse)
     /* We're reusing the connection - no need to resolve anything, and
-       fix_hostname() was called already in create_conn() for the re-use
+       idnconvert_hostname() was called already in create_conn() for the re-use
        case. */
     *async = FALSE;
 
@@ -3428,7 +3435,10 @@ static CURLcode resolve_server(struct Curl_easy *data,
         conn->port = conn->remote_port;
 
       /* Resolve target host right on */
-      rc = Curl_resolv_timeout(conn, connhost->name, (int)conn->port,
+      conn->hostname_resolve = strdup(connhost->name);
+      if(!conn->hostname_resolve)
+        return CURLE_OUT_OF_MEMORY;
+      rc = Curl_resolv_timeout(conn, conn->hostname_resolve, (int)conn->port,
                                &hostaddr, timeout_ms);
       if(rc == CURLRESOLV_PENDING)
         *async = TRUE;
@@ -3449,7 +3459,10 @@ static CURLcode resolve_server(struct Curl_easy *data,
         &conn->socks_proxy.host : &conn->http_proxy.host;
 
       /* resolve proxy */
-      rc = Curl_resolv_timeout(conn, host->name, (int)conn->port,
+      conn->hostname_resolve = strdup(host->name);
+      if(!conn->hostname_resolve)
+        return CURLE_OUT_OF_MEMORY;
+      rc = Curl_resolv_timeout(conn, conn->hostname_resolve, (int)conn->port,
                                &hostaddr, timeout_ms);
 
       if(rc == CURLRESOLV_PENDING)
@@ -3479,8 +3492,8 @@ static CURLcode resolve_server(struct Curl_easy *data,
 static void reuse_conn(struct connectdata *old_conn,
                        struct connectdata *conn)
 {
-  free_fixed_hostname(&old_conn->http_proxy.host);
-  free_fixed_hostname(&old_conn->socks_proxy.host);
+  free_idnconverted_hostname(&old_conn->http_proxy.host);
+  free_idnconverted_hostname(&old_conn->socks_proxy.host);
 
   free(old_conn->http_proxy.host.rawalloc);
   free(old_conn->socks_proxy.host.rawalloc);
@@ -3524,14 +3537,18 @@ static void reuse_conn(struct connectdata *old_conn,
 
   /* host can change, when doing keepalive with a proxy or if the case is
      different this time etc */
-  free_fixed_hostname(&conn->host);
-  free_fixed_hostname(&conn->conn_to_host);
+  free_idnconverted_hostname(&conn->host);
+  free_idnconverted_hostname(&conn->conn_to_host);
   Curl_safefree(conn->host.rawalloc);
   Curl_safefree(conn->conn_to_host.rawalloc);
   conn->host = old_conn->host;
   conn->conn_to_host = old_conn->conn_to_host;
   conn->conn_to_port = old_conn->conn_to_port;
   conn->remote_port = old_conn->remote_port;
+  Curl_safefree(conn->hostname_resolve);
+
+  conn->hostname_resolve = old_conn->hostname_resolve;
+  old_conn->hostname_resolve = NULL;
 
   /* persist connection info in session handle */
   Curl_persistconninfo(conn);
@@ -3681,30 +3698,30 @@ static CURLcode create_conn(struct Curl_easy *data,
     goto out;
 
   /*************************************************************
-   * IDN-fix the hostnames
+   * IDN-convert the hostnames
    *************************************************************/
-  result = fix_hostname(conn, &conn->host);
+  result = idnconvert_hostname(conn, &conn->host);
   if(result)
     goto out;
   if(conn->bits.conn_to_host) {
-    result = fix_hostname(conn, &conn->conn_to_host);
+    result = idnconvert_hostname(conn, &conn->conn_to_host);
     if(result)
       goto out;
   }
   if(conn->bits.httpproxy) {
-    result = fix_hostname(conn, &conn->http_proxy.host);
+    result = idnconvert_hostname(conn, &conn->http_proxy.host);
     if(result)
       goto out;
   }
   if(conn->bits.socksproxy) {
-    result = fix_hostname(conn, &conn->socks_proxy.host);
+    result = idnconvert_hostname(conn, &conn->socks_proxy.host);
     if(result)
       goto out;
   }
 
   /*************************************************************
    * Check whether the host and the "connect to host" are equal.
-   * Do this after the hostnames have been IDN-fixed.
+   * Do this after the hostnames have been IDN-converted.
    *************************************************************/
   if(conn->bits.conn_to_host &&
      strcasecompare(conn->conn_to_host.name, conn->host.name)) {
@@ -4032,6 +4049,15 @@ static CURLcode create_conn(struct Curl_easy *data,
    *************************************************************/
   result = resolve_server(data, conn, async);
 
+  /* Strip trailing dots. resolve_server copied the name. */
+  strip_trailing_dot(&conn->host);
+  if(conn->bits.httpproxy)
+    strip_trailing_dot(&conn->http_proxy.host);
+  if(conn->bits.socksproxy)
+    strip_trailing_dot(&conn->socks_proxy.host);
+  if(conn->bits.conn_to_host)
+    strip_trailing_dot(&conn->conn_to_host);
+
 out:
   return result;
 }
diff --git a/lib/urldata.h b/lib/urldata.h
index eae73a19f..448437d2a 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -828,6 +828,7 @@ struct connectdata {
   int socktype;  /* SOCK_STREAM or SOCK_DGRAM */
 
   struct hostname host;
+  char *hostname_resolve; /* host name to resolve to address, allocated */
   char *secondaryhostname; /* secondary socket host name (ftp) */
   struct hostname conn_to_host; /* the host to connect to. valid only if
                                    bits.conn_to_host is set */