Reducing CPU cycles spent calculating per-header length limit.

diff --git a/lib/parsers.c b/lib/parsers.c
index 07c5500..b71c63c 100644 (file)
--- a/lib/parsers.c
+++ b/lib/parsers.c
@@ -165,18 +165,15 @@ static char char_to_hex(const char c)
        return -1;
 }
 
-static int issue_char(
-               struct libwebsocket_context *context,
-               struct libwebsocket *wsi, unsigned char c)
+static int issue_char(struct libwebsocket *wsi, unsigned char c)
 {
        if (wsi->u.hdr.ah->pos == sizeof(wsi->u.hdr.ah->data)) {
                lwsl_warn("excessive header content\n");
                return -1;
        }
 
-       if( context->token_limits &&
-               (wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].len >= 
-               context->token_limits->token_limit[wsi->u.hdr.parser_state]) ) {
+       if( wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].len >= 
+               wsi->u.hdr.current_token_limit) {
                lwsl_warn("header %i exceeds limit\n", wsi->u.hdr.parser_state);
                return 1;
        };
@@ -246,7 +243,7 @@ int libwebsocket_parse(
                if (c == ' ') {
                        /* enforce starting with / */
                        if (!wsi->u.hdr.ah->frags[wsi->u.hdr.ah->next_frag_index].len)
-                               if (issue_char(context, wsi, '/') < 0)
+                               if (issue_char(wsi, '/') < 0)
                                        return -1;
                        c = '\0';
                        wsi->u.hdr.parser_state = WSI_TOKEN_SKIPPING;
@@ -265,7 +262,7 @@ int libwebsocket_parse(
                case URIES_SEEN_PERCENT:
                        if (char_to_hex(c) < 0) {
                                /* regurgitate */
-                               if (issue_char(context, wsi, '%') < 0)
+                               if (issue_char(wsi, '%') < 0)
                                        return -1;
                                wsi->u.hdr.ues = URIES_IDLE;
                                /* continue on to assess c */
@@ -278,7 +275,7 @@ int libwebsocket_parse(
                case URIES_SEEN_PERCENT_H1:
                        if (char_to_hex(c) < 0) {
                                /* regurgitate */
-                               issue_char(context, wsi, '%');
+                               issue_char(wsi, '%');
                                wsi->u.hdr.ues = URIES_IDLE;
                                /* regurgitate + assess */
                                if (libwebsocket_parse(context, wsi, wsi->u.hdr.esc_stash) < 0)
@@ -344,7 +341,7 @@ int libwebsocket_parse(
                        }
                        /* it was like /.dir ... regurgitate the . */
                        wsi->u.hdr.ups = URIPS_IDLE;
-                       issue_char(context, wsi, '.');
+                       issue_char(wsi, '.');
                        break;
                        
                case URIPS_SEEN_SLASH_DOT_DOT:
@@ -396,7 +393,7 @@ check_eol:
 
 spill:
                {
-                       int issue_result = issue_char(context, wsi, c);
+                       int issue_result = issue_char(wsi, c);
                        if (issue_result < 0) {
                                return -1;
                        }
@@ -444,7 +441,6 @@ swallow:
                        n = (lextable[wsi->u.hdr.lextable_pos] << 8) | lextable[wsi->u.hdr.lextable_pos + 1];
 
                        lwsl_parser("known hdr %d\n", n);
-
                        if (n == WSI_TOKEN_GET_URI &&
                                wsi->u.hdr.ah->frag_index[WSI_TOKEN_GET_URI]) {
                                lwsl_warn("Duplicated GET\n");
@@ -464,6 +460,15 @@ swallow:
 
                        wsi->u.hdr.parser_state = (enum lws_token_indexes)
                                                        (WSI_TOKEN_GET_URI + n);
+
+                       if( context->token_limits ) {
+                               wsi->u.hdr.current_token_limit = \
+                                       context->token_limits->token_limit[wsi->u.hdr.parser_state];
+                       }
+                       else {
+                               wsi->u.hdr.current_token_limit = sizeof(wsi->u.hdr.ah->data);
+                       };
+
                        if (wsi->u.hdr.parser_state == WSI_TOKEN_CHALLENGE)
                                goto set_parsing_complete;
 

diff --git a/lib/private-libwebsockets.h b/lib/private-libwebsockets.h
index 281bd7f..cd2f120 100755 (executable)
--- a/lib/private-libwebsockets.h
+++ b/lib/private-libwebsockets.h
@@ -529,6 +529,7 @@ struct _lws_http_mode_related {
 struct _lws_header_related {
        struct allocated_headers *ah;
        short lextable_pos;
+       unsigned short current_token_limit;
        unsigned char parser_state; /* enum lws_token_indexes */
        enum uri_path_states ups;
        enum uri_esc_states ues;