Promote SNI macros to functions.

BUG=404754

Change-Id: I2b2e27f3db0c97f2db65ca5e226c6488d2bee2fc
Reviewed-on: https://boringssl-review.googlesource.com/4570
Reviewed-by: Adam Langley <agl@google.com>

include/openssl/ssl.h

diff --git a/include/openssl/ssl.h b/include/openssl/ssl.h
index 9edc859..4ee2084 100644
--- a/include/openssl/ssl.h
+++ b/include/openssl/ssl.h
@@ -1571,8 +1571,6 @@
 #define SSL_CTRL_EXTRA_CHAIN_CERT 14
 
 /* see tls1.h for macros based on these */
-#define SSL_CTRL_SET_TLSEXT_SERVERNAME_ARG 54
-#define SSL_CTRL_SET_TLSEXT_HOSTNAME 55
 #define SSL_CTRL_GET_TLSEXT_TICKET_KEYS 58
 #define SSL_CTRL_SET_TLSEXT_TICKET_KEYS 59
 
@@ -2415,6 +2413,8 @@
 #define SSL_CTRL_SET_MAX_CERT_LIST doesnt_exist
 #define SSL_CTRL_SET_MAX_SEND_FRAGMENT doesnt_exist
 #define SSL_CTRL_SET_TLSEXT_SERVERNAME_CB doesnt_exist
+#define SSL_CTRL_SET_TLSEXT_SERVERNAME_ARG doesnt_exist
+#define SSL_CTRL_SET_TLSEXT_HOSTNAME doesnt_exist
 #define SSL_CTRL_SET_TLSEXT_TICKET_KEY_CB doesnt_exist
 #define DTLS_CTRL_GET_TIMEOUT doesnt_exist
 #define DTLS_CTRL_HANDLE_TIMEOUT doesnt_exist
@@ -2462,6 +2462,8 @@
 #define SSL_set_max_send_fragment SSL_set_max_send_fragment
 #define SSL_CTX_set_tlsext_servername_callback \
     SSL_CTX_set_tlsext_servername_callback
+#define SSL_CTX_set_tlsext_servername_arg SSL_CTX_set_tlsext_servername_arg
+#define SSL_set_tlsext_host_name SSL_set_tlsext_host_name
 #define SSL_CTX_set_tlsext_ticket_key_cb SSL_CTX_set_tlsext_ticket_key_cb
 #define DTLSv1_get_timeout DTLSv1_get_timeout
 #define DTLSv1_handle_timeout DTLSv1_handle_timeout
@@ -2675,6 +2677,7 @@
 #define SSL_F_SSL_set_tmp_ecdh 271
 #define SSL_F_SSL_CTX_set1_tls_channel_id 272
 #define SSL_F_SSL_set1_tls_channel_id 273
+#define SSL_F_SSL_set_tlsext_host_name 274
 #define SSL_R_APP_DATA_IN_HANDSHAKE 100
 #define SSL_R_ATTEMPT_TO_REUSE_SESSION_IN_DIFFERENT_CONTEXT 101
 #define SSL_R_BAD_ALERT 102

include/openssl/tls1.h

diff --git a/include/openssl/tls1.h b/include/openssl/tls1.h
index 707bf80..94c79db 100644
--- a/include/openssl/tls1.h
+++ b/include/openssl/tls1.h
@@ -317,9 +317,9 @@
                                           int *phash, int *psignandhash,
                                           uint8_t *rsig, uint8_t *rhash);
 
-#define SSL_set_tlsext_host_name(s, name)                              \
-  SSL_ctrl(s, SSL_CTRL_SET_TLSEXT_HOSTNAME, TLSEXT_NAMETYPE_host_name, \
-           (char *)name)
+/* SSL_set_tlsext_host_name, for a client, configures |ssl| to advertise |name|
+ * in the server_name extension. It returns one on success and zero on error. */
+OPENSSL_EXPORT int SSL_set_tlsext_host_name(SSL *ssl, const char *name);
 
 /* SSL_CTX_set_tlsext_servername_callback configures |callback| to be called on
  * the server after ClientHello extensions have been parsed and returns one.
@@ -336,8 +336,9 @@
 #define SSL_TLSEXT_ERR_ALERT_FATAL 2
 #define SSL_TLSEXT_ERR_NOACK 3
 
-#define SSL_CTX_set_tlsext_servername_arg(ctx, arg) \
-  SSL_CTX_ctrl(ctx, SSL_CTRL_SET_TLSEXT_SERVERNAME_ARG, 0, (void *)arg)
+/* SSL_CTX_set_tlsext_servername_arg sets the argument to the servername
+ * callback and returns one. See |SSL_CTX_set_tlsext_servername_callback|. */
+OPENSSL_EXPORT int SSL_CTX_set_tlsext_servername_arg(SSL_CTX *ctx, void *arg);
 
 #define SSL_CTX_get_tlsext_ticket_keys(ctx, keys, keylen) \
   SSL_CTX_ctrl((ctx), SSL_CTRL_GET_TLSEXT_TICKET_KEYS, (keylen), (keys))