Implement new lexer that is not generated by flex to reduce code size

1 files changed, 457 insertions, 0 deletions

diff --git a/src/lex.c b/src/lex.c
new file mode 100644
index 0000000..575d83e
--- /dev/null
+++ b/src/lex.c
@@ -0,0 +1,457 @@
+/*
+  Copyright (c) 2012-2013, Matthias Schiffer <mschiffer@universe-factory.net>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#include "lex.h"
+
+#include <stdlib.h>
+
+
+struct fastd_lex {
+	FILE *file;
+
+	bool needspace;
+
+	size_t start;
+	size_t end;
+	size_t tok_len;
+	char buffer[1024];
+};
+
+
+typedef struct keyword {
+	const char *keyword;
+	int token;
+} keyword_t;
+
+/* the keyword list must be sorted */
+static const keyword_t keywords[] = {
+	{ "addresses", TOK_ADDRESSES },
+	{ "any", TOK_ANY },
+	{ "as", TOK_AS },
+	{ "auto", TOK_AUTO },
+	{ "bind", TOK_BIND },
+	{ "capabilities", TOK_CAPABILITIES },
+	{ "crypto", TOK_CRYPTO },
+	{ "debug", TOK_DEBUG },
+	{ "default", TOK_DEFAULT },
+	{ "disestablish", TOK_DISESTABLISH },
+	{ "down", TOK_DOWN },
+	{ "drop", TOK_DROP },
+	{ "early", TOK_EARLY },
+	{ "error", TOK_ERROR },
+	{ "establish", TOK_ESTABLISH },
+	{ "fatal", TOK_FATAL },
+	{ "float", TOK_FLOAT },
+	{ "forward", TOK_FORWARD },
+	{ "from", TOK_FROM },
+	{ "group", TOK_GROUP },
+	{ "hide", TOK_HIDE },
+	{ "include", TOK_INCLUDE },
+	{ "info", TOK_INFO },
+	{ "interface", TOK_INTERFACE },
+	{ "ip", TOK_IP },
+	{ "ipv4", TOK_IPV4 },
+	{ "ipv6", TOK_IPV6 },
+	{ "key", TOK_KEY },
+	{ "level", TOK_LEVEL },
+	{ "limit", TOK_LIMIT },
+	{ "log", TOK_LOG },
+	{ "mac", TOK_MAC },
+	{ "method", TOK_METHOD },
+	{ "mode", TOK_MODE },
+	{ "mtu", TOK_MTU },
+	{ "no", TOK_NO },
+	{ "on", TOK_ON },
+	{ "peer", TOK_PEER },
+	{ "peers", TOK_PEERS },
+	{ "pmtu", TOK_PMTU },
+	{ "port", TOK_PORT },
+	{ "post-down", TOK_POST_DOWN },
+	{ "pre-up", TOK_PRE_UP },
+	{ "protocol", TOK_PROTOCOL },
+	{ "remote", TOK_REMOTE },
+	{ "secret", TOK_SECRET },
+	{ "stderr", TOK_STDERR },
+	{ "syslog", TOK_SYSLOG },
+	{ "tap", TOK_TAP },
+	{ "to", TOK_TO },
+	{ "tun", TOK_TUN },
+	{ "up", TOK_UP },
+	{ "use", TOK_USE },
+	{ "user", TOK_USER },
+	{ "verbose", TOK_VERBOSE },
+	{ "verify", TOK_VERIFY },
+	{ "warn", TOK_WARN },
+	{ "yes", TOK_YES },
+};
+
+static int compare_keywords(const void *v1, const void *v2) {
+	const keyword_t *k1 = v1, *k2 = v2;
+	return strcmp(k1->keyword, k2->keyword);
+}
+
+
+static bool advance(fastd_lex_t *lex) {
+	if (lex->start > 0) {
+		memmove(lex->buffer, lex->buffer+lex->start, lex->end - lex->start);
+		lex->end -= lex->start;
+		lex->start = 0;
+	}
+
+	if (lex->end == sizeof(lex->buffer))
+		return false;
+
+	size_t l = fread(lex->buffer+lex->end, 1, sizeof(lex->buffer) - lex->end, lex->file);
+
+	lex->end += l;
+	return l;
+}
+
+static inline char current(fastd_lex_t *lex) {
+	return lex->buffer[lex->start + lex->tok_len];
+}
+
+static char* get_token(fastd_lex_t *lex) {
+	return strndup(lex->buffer+lex->start, lex->tok_len);
+}
+
+static bool next(YYLTYPE *yylloc, fastd_lex_t *lex, bool move) {
+	if (lex->start + lex->tok_len >= lex->end)
+		return false;
+
+	if (current(lex) == '\n') {
+		yylloc->last_column = 0;
+		yylloc->last_line++;
+	}
+	else {
+		yylloc->last_column++;
+	}
+
+	if (move)
+		lex->start++;
+	else
+		lex->tok_len++;
+
+
+	if (lex->start + lex->tok_len >= lex->end)
+		return advance(lex);
+
+	return true;
+}
+
+static void consume(fastd_lex_t *lex, bool needspace) {
+	lex->start += lex->tok_len;
+	lex->tok_len = 0;
+
+	lex->needspace = needspace;
+}
+
+static int syntax_error(YYSTYPE *yylval, fastd_lex_t *lex) {
+	yylval->error = "syntax error";
+	return -1;
+}
+
+static int io_error(YYSTYPE *yylval, fastd_lex_t *lex) {
+	yylval->error = "I/O error";
+	return -1;
+}
+
+static inline int end(YYSTYPE *yylval, fastd_lex_t *lex) {
+	if (ferror(lex->file))
+		return io_error(yylval, lex);
+
+	return 0;
+}
+
+static int consume_comment(YYSTYPE *yylval, YYLTYPE *yylloc, fastd_lex_t *lex) {
+	char prev = 0;
+
+	while (next(yylloc, lex, true)) {
+		if (prev == '*' && current(lex) == '/') {
+			next(yylloc, lex, true);
+			consume(lex, false);
+			return 0;
+		}
+
+		prev = current(lex);
+	}
+
+	if (ferror(lex->file))
+		return io_error(yylval, lex);
+
+	yylval->error = "unterminated block comment";
+	return -1;
+}
+
+static int unterminated_string(YYSTYPE *yylval, fastd_lex_t *lex) {
+	if (ferror(lex->file))
+		return io_error(yylval, lex);
+
+	yylval->error = "unterminated string";
+	return -1;
+}
+
+static int parse_string(YYSTYPE *yylval, YYLTYPE *yylloc, fastd_lex_t *lex) {
+	char *buf = NULL;
+	size_t len = 1024;
+	size_t pos = 0;
+
+	if (lex->needspace)
+		return syntax_error(yylval, lex);
+
+	buf = malloc(len);
+
+	while (true) {
+		if (!next(yylloc, lex, true)) {
+			free(buf);
+			return unterminated_string(yylval, lex);
+		}
+
+		char cur = current(lex);
+
+		if (cur == '"')
+			break;
+
+		if (cur == '\\') {
+			if (!next(yylloc, lex, true)) {
+				free(buf);
+				return unterminated_string(yylval, lex);
+			}
+
+			cur = current(lex);
+
+			if (cur == '\n')
+				continue;
+		}
+
+		if (pos >= len) {
+			len *= 2;
+			buf = realloc(buf, len);
+		}
+
+		buf[pos++] = cur;
+	}
+
+	yylval->str = fastd_string_stack_dupn(buf, pos);
+	free(buf);
+
+	next(yylloc, lex, true);
+	consume(lex, true);
+
+	return TOK_STRING;
+}
+
+static int parse_ipv6_address(YYSTYPE *yylval, YYLTYPE *yylloc, fastd_lex_t *lex) {
+	if (lex->needspace)
+		return syntax_error(yylval, lex);
+
+	while (next(yylloc, lex, false)) {
+		char cur = current(lex);
+
+		if (!((cur >= '0' && cur <= '9') || cur == ':'))
+			break;
+	}
+
+	bool ok = (current(lex) == ']');
+
+	if (ok) {
+		lex->buffer[lex->start + lex->tok_len] = 0;
+		ok = inet_pton(AF_INET6, lex->buffer+lex->start+1, &yylval->addr6);
+	}
+
+	if (!ok) {
+		yylval->error = "invalid address";
+		return -1;
+	}
+
+	next(yylloc, lex, true);
+	consume(lex, true);
+
+	return TOK_ADDR6;
+}
+
+static int parse_ipv4_address(YYSTYPE *yylval, YYLTYPE *yylloc, fastd_lex_t *lex) {
+	if (lex->needspace)
+		return syntax_error(yylval, lex);
+
+	while (next(yylloc, lex, false)) {
+		char cur = current(lex);
+
+		if (!((cur >= '0' && cur <= '9') || cur == '.'))
+			break;
+	}
+
+	char *token = get_token(lex);
+	bool ok = inet_pton(AF_INET, token, &yylval->addr4);
+
+	free(token);
+
+	if (!ok) {
+		yylval->error = "invalid address";
+		return -1;
+	}
+
+	return TOK_ADDR4;
+}
+
+static int parse_number(YYSTYPE *yylval, YYLTYPE *yylloc, fastd_lex_t *lex) {
+	if (lex->needspace)
+		return syntax_error(yylval, lex);
+
+	while (next(yylloc, lex, false)) {
+		char cur = current(lex);
+
+		if (cur == '.')
+			return parse_ipv4_address(yylval, yylloc, lex);
+
+		if (!(cur >= '0' && cur <= '9'))
+			break;
+	}
+
+	char *endptr, *token = get_token(lex);
+	yylval->uint64 = strtoull(token, &endptr, 10);
+
+	bool ok = !*endptr;
+	free(token);
+
+	if (!ok) {
+		yylval->error = "invalid integer constant";
+		return -1;
+	}
+
+	return TOK_UINT;
+}
+
+static int parse_keyword(YYSTYPE *yylval, YYLTYPE *yylloc, fastd_lex_t *lex) {
+	if (lex->needspace)
+		return syntax_error(yylval, lex);
+
+	while (next(yylloc, lex, false)) {
+		char cur = current(lex);
+
+		if (!((cur >= 'a' && cur <= 'z') || (cur >= '0' && cur <= '9') || cur == '-'))
+			break;
+	}
+
+	char *token = get_token(lex);
+	const keyword_t key = {token};
+	const keyword_t *ret = bsearch(&key, keywords, sizeof(keywords)/sizeof(keyword_t), sizeof(keyword_t), compare_keywords);
+	free(token);
+
+	if (!ret)
+		return syntax_error(yylval, lex);
+
+	consume(lex, true);
+
+	return ret->token;
+}
+
+fastd_lex_t* fastd_lex_init(FILE *file) {
+	fastd_lex_t *lex = calloc(1, sizeof(fastd_lex_t));
+	lex->file = file;
+
+	advance(lex);
+
+	return lex;
+}
+
+void fastd_lex_destroy(fastd_lex_t *lex) {
+	if (!lex)
+		return;
+
+	free(lex);
+}
+
+int fastd_lex(YYSTYPE *yylval, YYLTYPE *yylloc, fastd_lex_t *lex) {
+	int token;
+
+	while (lex->end > lex->start) {
+		yylloc->first_line = yylloc->last_line;
+		yylloc->first_column = yylloc->last_column+1;
+
+		switch (current(lex)) {
+		case ' ':
+		case '\n':
+		case '\t':
+		case '\r':
+			next(yylloc, lex, true);
+			consume(lex, false);
+			continue;
+
+		case ';':
+		case ':':
+		case '{':
+		case '}':
+			token = current(lex);
+			next(yylloc, lex, true);
+			consume(lex, false);
+			return token;
+
+		case '/':
+			if (!next(yylloc, lex, true))
+				return syntax_error(yylval, lex);
+
+			if (current(lex) == '*') {
+				token = consume_comment(yylval, yylloc, lex);
+				if (token)
+					return token;
+
+				continue;
+			}
+
+			if (current(lex) != '/')
+				return syntax_error(yylval, lex);
+
+			/* fall-through */
+		case '#':
+			while (next(yylloc, lex, true)) {
+				if (current(lex) == '\n')
+					break;
+			}
+
+			next(yylloc, lex, true);
+			consume(lex, false);
+			continue;
+
+		case '"':
+			return parse_string(yylval, yylloc, lex);
+
+		case '[':
+			return parse_ipv6_address(yylval, yylloc, lex);
+
+		case '0' ... '9':
+			return parse_number(yylval, yylloc, lex);
+
+		case 'a' ... 'z':
+			return parse_keyword(yylval, yylloc, lex);
+
+		default:
+			return syntax_error(yylval, lex);
+		}
+	}
+
+	return end(yylval, lex);
+}