Stream ssl_preread: $ssl_preread_alpn_protocols variable.

The variable keeps a comma-separated list of protocol names from ALPN TLS
extension defined by RFC 7301.
This commit is contained in:
Roman Arutyunyan 2018-03-12 16:03:08 +03:00
parent 84d1e7de0c
commit 1a5604bedd

View File

@ -17,10 +17,12 @@ typedef struct {
typedef struct {
size_t left;
size_t size;
size_t ext;
u_char *pos;
u_char *dst;
u_char buf[4];
ngx_str_t host;
ngx_str_t alpn;
ngx_log_t *log;
ngx_pool_t *pool;
ngx_uint_t state;
@ -32,6 +34,8 @@ static ngx_int_t ngx_stream_ssl_preread_parse_record(
ngx_stream_ssl_preread_ctx_t *ctx, u_char *pos, u_char *last);
static ngx_int_t ngx_stream_ssl_preread_server_name_variable(
ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_ssl_preread_alpn_protocols_variable(
ngx_stream_session_t *s, ngx_stream_variable_value_t *v, uintptr_t data);
static ngx_int_t ngx_stream_ssl_preread_add_variables(ngx_conf_t *cf);
static void *ngx_stream_ssl_preread_create_srv_conf(ngx_conf_t *cf);
static char *ngx_stream_ssl_preread_merge_srv_conf(ngx_conf_t *cf, void *parent,
@ -85,6 +89,9 @@ static ngx_stream_variable_t ngx_stream_ssl_preread_vars[] = {
{ ngx_string("ssl_preread_server_name"), NULL,
ngx_stream_ssl_preread_server_name_variable, 0, 0, 0 },
{ ngx_string("ssl_preread_alpn_protocols"), NULL,
ngx_stream_ssl_preread_alpn_protocols_variable, 0, 0, 0 },
ngx_stream_null_variable
};
@ -139,12 +146,14 @@ ngx_stream_ssl_preread_handler(ngx_stream_session_t *s)
if (p[0] != 0x16) {
ngx_log_debug0(NGX_LOG_DEBUG_STREAM, ctx->log, 0,
"ssl preread: not a handshake");
ngx_stream_set_ctx(s, NULL, ngx_stream_ssl_preread_module);
return NGX_DECLINED;
}
if (p[1] != 3) {
ngx_log_debug0(NGX_LOG_DEBUG_STREAM, ctx->log, 0,
"ssl preread: unsupported SSL version");
ngx_stream_set_ctx(s, NULL, ngx_stream_ssl_preread_module);
return NGX_DECLINED;
}
@ -158,6 +167,12 @@ ngx_stream_ssl_preread_handler(ngx_stream_session_t *s)
p += 5;
rc = ngx_stream_ssl_preread_parse_record(ctx, p, p + len);
if (rc == NGX_DECLINED) {
ngx_stream_set_ctx(s, NULL, ngx_stream_ssl_preread_module);
return NGX_DECLINED;
}
if (rc != NGX_AGAIN) {
return rc;
}
@ -175,7 +190,7 @@ static ngx_int_t
ngx_stream_ssl_preread_parse_record(ngx_stream_ssl_preread_ctx_t *ctx,
u_char *pos, u_char *last)
{
size_t left, n, size;
size_t left, n, size, ext;
u_char *dst, *p;
enum {
@ -192,7 +207,10 @@ ngx_stream_ssl_preread_parse_record(ngx_stream_ssl_preread_ctx_t *ctx,
sw_ext_header, /* extension_type, extension_data length */
sw_sni_len, /* SNI length */
sw_sni_host_head, /* SNI name_type, host_name length */
sw_sni_host /* SNI host_name */
sw_sni_host, /* SNI host_name */
sw_alpn_len, /* ALPN length */
sw_alpn_proto_len, /* ALPN protocol_name length */
sw_alpn_proto_data /* ALPN protocol_name */
} state;
ngx_log_debug2(NGX_LOG_DEBUG_STREAM, ctx->log, 0,
@ -201,6 +219,7 @@ ngx_stream_ssl_preread_parse_record(ngx_stream_ssl_preread_ctx_t *ctx,
state = ctx->state;
size = ctx->size;
left = ctx->left;
ext = ctx->ext;
dst = ctx->dst;
p = ctx->buf;
@ -299,10 +318,18 @@ ngx_stream_ssl_preread_parse_record(ngx_stream_ssl_preread_ctx_t *ctx,
break;
case sw_ext_header:
if (p[0] == 0 && p[1] == 0) {
if (p[0] == 0 && p[1] == 0 && ctx->host.data == NULL) {
/* SNI extension */
state = sw_sni_len;
dst = NULL;
dst = p;
size = 2;
break;
}
if (p[0] == 0 && p[1] == 16 && ctx->alpn.data == NULL) {
/* ALPN extension */
state = sw_alpn_len;
dst = p;
size = 2;
break;
}
@ -313,6 +340,7 @@ ngx_stream_ssl_preread_parse_record(ngx_stream_ssl_preread_ctx_t *ctx,
break;
case sw_sni_len:
ext = (p[0] << 8) + p[1];
state = sw_sni_host_head;
dst = p;
size = 3;
@ -325,14 +353,21 @@ ngx_stream_ssl_preread_parse_record(ngx_stream_ssl_preread_ctx_t *ctx,
return NGX_DECLINED;
}
state = sw_sni_host;
size = (p[1] << 8) + p[2];
if (ext < 3 + size) {
ngx_log_debug0(NGX_LOG_DEBUG_STREAM, ctx->log, 0,
"ssl preread: SNI format error");
return NGX_DECLINED;
}
ext -= 3 + size;
ctx->host.data = ngx_pnalloc(ctx->pool, size);
if (ctx->host.data == NULL) {
return NGX_ERROR;
}
state = sw_sni_host;
dst = ctx->host.data;
break;
@ -341,7 +376,64 @@ ngx_stream_ssl_preread_parse_record(ngx_stream_ssl_preread_ctx_t *ctx,
ngx_log_debug1(NGX_LOG_DEBUG_STREAM, ctx->log, 0,
"ssl preread: SNI hostname \"%V\"", &ctx->host);
return NGX_OK;
state = sw_ext;
dst = NULL;
size = ext;
break;
case sw_alpn_len:
ext = (p[0] << 8) + p[1];
ctx->alpn.data = ngx_pnalloc(ctx->pool, ext);
if (ctx->alpn.data == NULL) {
return NGX_ERROR;
}
state = sw_alpn_proto_len;
dst = p;
size = 1;
break;
case sw_alpn_proto_len:
size = p[0];
if (size == 0) {
ngx_log_debug0(NGX_LOG_DEBUG_STREAM, ctx->log, 0,
"ssl preread: ALPN empty protocol");
return NGX_DECLINED;
}
if (ext < 1 + size) {
ngx_log_debug0(NGX_LOG_DEBUG_STREAM, ctx->log, 0,
"ssl preread: ALPN format error");
return NGX_DECLINED;
}
ext -= 1 + size;
state = sw_alpn_proto_data;
dst = ctx->alpn.data + ctx->alpn.len;
break;
case sw_alpn_proto_data:
ctx->alpn.len += p[0];
ngx_log_debug1(NGX_LOG_DEBUG_STREAM, ctx->log, 0,
"ssl preread: ALPN protocols \"%V\"", &ctx->alpn);
if (ext) {
ctx->alpn.data[ctx->alpn.len++] = ',';
state = sw_alpn_proto_len;
dst = p;
size = 1;
break;
}
state = sw_ext;
dst = NULL;
size = 0;
break;
}
if (left < size) {
@ -354,6 +446,7 @@ ngx_stream_ssl_preread_parse_record(ngx_stream_ssl_preread_ctx_t *ctx,
ctx->state = state;
ctx->size = size;
ctx->left = left;
ctx->ext = ext;
ctx->dst = dst;
return NGX_AGAIN;
@ -383,6 +476,29 @@ ngx_stream_ssl_preread_server_name_variable(ngx_stream_session_t *s,
}
static ngx_int_t
ngx_stream_ssl_preread_alpn_protocols_variable(ngx_stream_session_t *s,
ngx_variable_value_t *v, uintptr_t data)
{
ngx_stream_ssl_preread_ctx_t *ctx;
ctx = ngx_stream_get_module_ctx(s, ngx_stream_ssl_preread_module);
if (ctx == NULL) {
v->not_found = 1;
return NGX_OK;
}
v->valid = 1;
v->no_cacheable = 0;
v->not_found = 0;
v->len = ctx->alpn.len;
v->data = ctx->alpn.data;
return NGX_OK;
}
static ngx_int_t
ngx_stream_ssl_preread_add_variables(ngx_conf_t *cf)
{