vtls: factor out Curl_ssl_getsock to field of Curl_ssl

Closes #6558

lib/vtls/bearssl.c

@@ -855,6 +855,7 @@ const struct Curl_ssl Curl_ssl_bearssl = {
   Curl_none_cert_status_request,
   bearssl_connect,
   bearssl_connect_nonblocking,
+  Curl_ssl_getsock,
   bearssl_get_internals,
   bearssl_close,
   Curl_none_close_all,

lib/vtls/gtls.c

@@ -1671,6 +1671,7 @@ const struct Curl_ssl Curl_ssl_gnutls = {
   gtls_cert_status_request,      /* cert_status_request */
   gtls_connect,                  /* connect */
   gtls_connect_nonblocking,      /* connect_nonblocking */
+  Curl_ssl_getsock,              /* getsock */
   gtls_get_internals,            /* get_internals */
   gtls_close,                    /* close_one */
   Curl_none_close_all,           /* close_all */

lib/vtls/mbedtls.c

@@ -1100,6 +1100,7 @@ const struct Curl_ssl Curl_ssl_mbedtls = {
   Curl_none_cert_status_request,    /* cert_status_request */
   mbedtls_connect,                  /* connect */
   mbedtls_connect_nonblocking,      /* connect_nonblocking */
+  Curl_ssl_getsock,                 /* getsock */
   mbedtls_get_internals,            /* get_internals */
   mbedtls_close,                    /* close_one */
   mbedtls_close_all,                /* close_all */

lib/vtls/mesalink.c

@@ -654,6 +654,7 @@ const struct Curl_ssl Curl_ssl_mesalink = {
   Curl_none_cert_status_request, /* cert_status_request */
   mesalink_connect,              /* connect */
   mesalink_connect_nonblocking,  /* connect_nonblocking */
+  Curl_ssl_getsock,              /* getsock */
   mesalink_get_internals,        /* get_internals */
   mesalink_close,                /* close_one */
   Curl_none_close_all,           /* close_all */

lib/vtls/nss.c

@@ -2435,6 +2435,7 @@ const struct Curl_ssl Curl_ssl_nss = {
   nss_cert_status_request,      /* cert_status_request */
   nss_connect,                  /* connect */
   nss_connect_nonblocking,      /* connect_nonblocking */
+  Curl_ssl_getsock,             /* getsock */
   nss_get_internals,            /* get_internals */
   nss_close,                    /* close_one */
   Curl_none_close_all,          /* close_all */

lib/vtls/openssl.c

@@ -4477,6 +4477,7 @@ const struct Curl_ssl Curl_ssl_openssl = {
   ossl_cert_status_request, /* cert_status_request */
   ossl_connect,             /* connect */
   ossl_connect_nonblocking, /* connect_nonblocking */
+  Curl_ssl_getsock,         /* getsock */
   ossl_get_internals,       /* get_internals */
   ossl_close,               /* close_one */
   ossl_close_all,           /* close_all */

lib/vtls/schannel.c

@@ -2418,6 +2418,7 @@ const struct Curl_ssl Curl_ssl_schannel = {
   Curl_none_cert_status_request,     /* cert_status_request */
   schannel_connect,                  /* connect */
   schannel_connect_nonblocking,      /* connect_nonblocking */
+  Curl_ssl_getsock,                  /* getsock */
   schannel_get_internals,            /* get_internals */
   schannel_close,                    /* close_one */
   Curl_none_close_all,               /* close_all */

lib/vtls/sectransp.c

@@ -3301,6 +3301,7 @@ const struct Curl_ssl Curl_ssl_sectransp = {
   Curl_none_cert_status_request,      /* cert_status_request */
   sectransp_connect,                  /* connect */
   sectransp_connect_nonblocking,      /* connect_nonblocking */
+  Curl_ssl_getsock,                   /* getsock */
   sectransp_get_internals,            /* get_internals */
   sectransp_close,                    /* close_one */
   Curl_none_close_all,                /* close_all */

lib/vtls/vtls.c

@@ -593,9 +593,6 @@ void Curl_ssl_close_all(struct Curl_easy *data)
   Curl_ssl->close_all(data);
 }
 
-#if defined(USE_OPENSSL) || defined(USE_GNUTLS) || defined(USE_SCHANNEL) || \
-  defined(USE_SECTRANSP) || defined(USE_NSS) || \
-  defined(USE_MBEDTLS) || defined(USE_WOLFSSL) || defined(USE_BEARSSL)
 int Curl_ssl_getsock(struct connectdata *conn, curl_socket_t *socks)
 {
   struct ssl_connect_data *connssl = &conn->ssl[FIRSTSOCKET];
@@ -613,16 +610,6 @@ int Curl_ssl_getsock(struct connectdata *conn, curl_socket_t *socks)
 
   return GETSOCK_BLANK;
 }
-#else
-int Curl_ssl_getsock(struct connectdata *conn,
-                     curl_socket_t *socks)
-{
-  (void)conn;
-  (void)socks;
-  return GETSOCK_BLANK;
-}
-/* USE_OPENSSL || USE_GNUTLS || USE_SCHANNEL || USE_SECTRANSP || USE_NSS */
-#endif
 
 void Curl_ssl_close(struct Curl_easy *data, struct connectdata *conn,
                     int sockindex)
@@ -1170,6 +1157,13 @@ static CURLcode multissl_connect_nonblocking(struct Curl_easy *data,
   return Curl_ssl->connect_nonblocking(data, conn, sockindex, done);
 }
 
+static int multissl_getsock(struct connectdata *conn, curl_socket_t *socks)
+{
+  if(multissl_setup(NULL))
+    return 0;
+  return Curl_ssl->getsock(conn, socks);
+}
+
 static void *multissl_get_internals(struct ssl_connect_data *connssl,
                                     CURLINFO info)
 {
@@ -1201,6 +1195,7 @@ static const struct Curl_ssl Curl_ssl_multi = {
   Curl_none_cert_status_request,     /* cert_status_request */
   multissl_connect,                  /* connect */
   multissl_connect_nonblocking,      /* connect_nonblocking */
+  multissl_getsock,                  /* getsock */
   multissl_get_internals,            /* get_internals */
   multissl_close,                    /* close_one */
   Curl_none_close_all,               /* close_all */

lib/vtls/vtls.h

@@ -62,6 +62,14 @@ struct Curl_ssl {
   CURLcode (*connect_nonblocking)(struct Curl_easy *data,
                                   struct connectdata *conn, int sockindex,
                                   bool *done);
+
+  /* If the SSL backend wants to read or write on this connection during a
+     handshake, set socks[0] to the connection's FIRSTSOCKET, and return
+     a bitmap indicating read or write with GETSOCK_WRITESOCK(0) or
+     GETSOCK_READSOCK(0). Otherwise return GETSOCK_BLANK.
+     Mandatory. */
+  int (*getsock)(struct connectdata *conn, curl_socket_t *socks);
+
   void *(*get_internals)(struct ssl_connect_data *connssl, CURLINFO info);
   void (*close_one)(struct Curl_easy *data, struct connectdata *conn,
                     int sockindex);
@@ -158,6 +166,10 @@ bool Curl_ssl_config_matches(struct ssl_primary_config *data,
 bool Curl_clone_primary_ssl_config(struct ssl_primary_config *source,
                                    struct ssl_primary_config *dest);
 void Curl_free_primary_ssl_config(struct ssl_primary_config *sslc);
+/* An implementation of the getsock field of Curl_ssl that relies
+   on the ssl_connect_state enum. Asks for read or write depending
+   on whether conn->state is ssl_connect_2_reading or
+   ssl_connect_2_writing. */
 int Curl_ssl_getsock(struct connectdata *conn, curl_socket_t *socks);
 
 int Curl_ssl_backend(void);

lib/vtls/wolfssl.c

@@ -1152,6 +1152,7 @@ const struct Curl_ssl Curl_ssl_wolfssl = {
   Curl_none_cert_status_request,   /* cert_status_request */
   wolfssl_connect,                 /* connect */
   wolfssl_connect_nonblocking,     /* connect_nonblocking */
+  Curl_ssl_getsock,                /* getsock */
   wolfssl_get_internals,           /* get_internals */
   wolfssl_close,                   /* close_one */
   Curl_none_close_all,             /* close_all */