res_http_websocket: Create a websocket client

Added a websocket server client in Asterisk. Asterisk has a websocket server,
but not a client. The ability to have Asterisk be able to connect to a websocket
server can potentially be useful for future work (for instance this could allow
ARI to connect back to some external system, although more work would be needed
in order to incorporate that).

Also a couple of things to note - proxy connection support has not been
implemented and there is limited http response code handling (basically, it is
connect or not).

Also added an initial new URI handling mechanism to core.  Internet type URI's
are parsed into a data structure that contains pointers to the various parts of
the URI.

(closes issue ASTERISK-23742)
Reported by: Kevin Harwell
Review: https://reviewboard.asterisk.org/r/3541/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@415223 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/http.c

@@ -1176,6 +1176,113 @@ struct ast_http_auth *ast_http_get_auth(struct ast_variable *headers)
 	return NULL;
 }
 
+int ast_http_response_status_line(const char *buf, const char *version, int code)
+{
+	int status_code;
+	size_t size = strlen(version);
+
+	if (strncmp(buf, version, size) || buf[size] != ' ') {
+		ast_log(LOG_ERROR, "HTTP version not supported - "
+			"expected %s\n", version);
+		return -1;
+	}
+
+	/* skip to status code (version + space) */
+	buf += size + 1;
+
+	if (sscanf(buf, "%d", &status_code) != 1) {
+		ast_log(LOG_ERROR, "Could not read HTTP status code - "
+			"%s\n", buf);
+		return -1;
+	}
+
+	return status_code;
+}
+
+static void remove_excess_lws(char *s)
+{
+	char *p, *res = s;
+	char *buf = ast_malloc(strlen(s) + 1);
+	char *buf_end;
+
+	if (!buf) {
+		return;
+	}
+
+	buf_end = buf;
+
+	while (*s && *(s = ast_skip_blanks(s))) {
+		p = s;
+		s = ast_skip_nonblanks(s);
+
+		if (buf_end != buf) {
+			*buf_end++ = ' ';
+		}
+
+		memcpy(buf_end, p, s - p);
+		buf_end += s - p;
+	}
+	*buf_end = '\0';
+	/* safe since buf will always be less than or equal to res */
+	strcpy(res, buf);
+	ast_free(buf);
+}
+
+int ast_http_header_parse(char *buf, char **name, char **value)
+{
+	ast_trim_blanks(buf);
+	if (ast_strlen_zero(buf)) {
+		return -1;
+	}
+
+	*value = buf;
+	*name = strsep(value, ":");
+	if (!*value) {
+		return 1;
+	}
+
+	*value = ast_skip_blanks(*value);
+	if (ast_strlen_zero(*value) || ast_strlen_zero(*name)) {
+		return 1;
+	}
+
+	remove_excess_lws(*value);
+	return 0;
+}
+
+int ast_http_header_match(const char *name, const char *expected_name,
+			  const char *value, const char *expected_value)
+{
+	if (strcasecmp(name, expected_name)) {
+		/* no value to validate if names don't match */
+		return 0;
+	}
+
+	if (strcasecmp(value, expected_value)) {
+		ast_log(LOG_ERROR, "Invalid header value - expected %s "
+			"received %s", value, expected_value);
+		return -1;
+	}
+	return 1;
+}
+
+int ast_http_header_match_in(const char *name, const char *expected_name,
+			     const char *value, const char *expected_value)
+{
+	if (strcasecmp(name, expected_name)) {
+		/* no value to validate if names don't match */
+		return 0;
+	}
+
+	if (!strcasestr(expected_value, value)) {
+		ast_log(LOG_ERROR, "Header '%s' - could not locate '%s' "
+			"in '%s'\n", name, value, expected_value);
+		return -1;
+
+	}
+	return 1;
+}
+
 /*! Limit the number of request headers in case the sender is being ridiculous. */
 #define MAX_HTTP_REQUEST_HEADERS	100