chan_sip: Isolate code that manages struct sip_route.

* Move route code to sip/route.c + sip/include/route.h
* Rename functions to sip_route_*
* Replace ad-hoc list code with macro's from linkedlists.h
* Create sip_route_process_header() to processes Path and Record-Route headers
  (previously done with different code in build_route and build_path)
* Add use of const where possible
* Move struct uriparams, struct contact and contactliststruct from sip.h to
  reqresp_parser.h.  sip/route.c uses reqresp_parser.h but not sip.h, this was
  a problem.  These moved declares are not used outside of reqresp_parser.
* While modifying reqprep() the lack of {} caused me trouble.  I added them.
* Code outside route.c treats sip_route as an opaque structure, using macro's
  or procedures for all access.

(closes issue ASTERISK-22582)
Reported by: Corey Farrell
Review: https://reviewboard.asterisk.org/r/3173/


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@407926 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/sip/route.c

@@ -0,0 +1,205 @@
+/*
+ * Asterisk -- An open source telephony toolkit.
+ *
+ * Copyright (C) 2013, Digium, Inc.
+ *
+ * See http://www.asterisk.org for more information about
+ * the Asterisk project. Please do not directly contact
+ * any of the maintainers of this project for assistance;
+ * the project provides a web site, mailing lists and IRC
+ * channels for your use.
+ *
+ * This program is free software, distributed under the terms of
+ * the GNU General Public License Version 2. See the LICENSE file
+ * at the top of the source tree.
+ */
+
+/*!
+ * \file
+ * \brief sip_route functions
+ */
+
+/*** MODULEINFO
+	<support_level>core</support_level>
+ ***/
+
+#include "asterisk.h"
+
+ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
+
+#include "asterisk/utils.h"
+
+#include "include/route.h"
+#include "include/reqresp_parser.h"
+
+/*!
+ * \brief Traverse route hops
+ */
+#define sip_route_traverse(route,elem) AST_LIST_TRAVERSE(&(route)->list, elem, list)
+#define sip_route_first(route) AST_LIST_FIRST(&(route)->list)
+
+/*!
+ * \brief Structure to save a route hop
+ */
+struct sip_route_hop {
+	AST_LIST_ENTRY(sip_route_hop) list;
+	char uri[0];
+};
+
+const char *sip_route_add(struct sip_route *route, const char *uri, size_t len, int inserthead)
+{
+	struct sip_route_hop *hop;
+
+	if (!uri || len < 1 || uri[0] == '\0') {
+		return NULL;
+	}
+
+	/* Expand len to include null terminator */
+	len++;
+
+	/* ast_calloc is not needed because all fields are initialized in this block */
+	hop = ast_malloc(sizeof(struct sip_route_hop) + len);
+	if (!hop) {
+		return NULL;
+	}
+	ast_copy_string(hop->uri, uri, len);
+
+	if (inserthead) {
+		AST_LIST_INSERT_HEAD(&route->list, hop, list);
+		route->type = route_invalidated;
+	} else {
+		if (sip_route_empty(route)) {
+			route->type = route_invalidated;
+		}
+		AST_LIST_INSERT_TAIL(&route->list, hop, list);
+		hop->list.next = NULL;
+	}
+
+	return hop->uri;
+}
+
+void sip_route_process_header(struct sip_route *route, const char *header, int inserthead)
+{
+	const char *hop;
+	int len = 0;
+	const char *uri;
+
+	if (!route) {
+		ast_log(LOG_ERROR, "sip_route_process_header requires non-null route");
+		ast_do_crash();
+		return;
+	}
+
+	while (!get_in_brackets_const(header, &uri, &len)) {
+		header = strchr(header, ',');
+		if (header >= uri && header <= (uri + len)) {
+			/* comma inside brackets */
+			const char *next_br = strchr(header, '<');
+			if (next_br && next_br <= (uri + len)) {
+				header++;
+				continue;
+			}
+			continue;
+		}
+		if ((hop = sip_route_add(route, uri, len, inserthead))) {
+			ast_debug(2, "sip_route_process_header: <%s>\n", hop);
+		}
+		header = strchr(uri + len + 1, ',');
+		if (header == NULL) {
+			/* No more field-values, we're done with this header */
+			break;
+		}
+		/* Advance past comma */
+		header++;
+	}
+}
+
+void sip_route_copy(struct sip_route *dst, const struct sip_route *src)
+{
+	struct sip_route_hop *hop;
+
+	/* make sure dst is empty */
+	sip_route_clear(dst);
+
+	sip_route_traverse(src, hop) {
+		const char *uri = sip_route_add(dst, hop->uri, strlen(hop->uri), 0);
+		if (uri) {
+			ast_debug(2, "sip_route_copy: copied hop: <%s>\n", uri);
+		}
+	}
+
+	dst->type = src->type;
+}
+
+void sip_route_clear(struct sip_route *route)
+{
+	struct sip_route_hop *hop;
+
+	while ((hop = AST_LIST_REMOVE_HEAD(&route->list, list))) {
+		ast_free(hop);
+	}
+
+	route->type = route_loose;
+}
+
+void sip_route_dump(const struct sip_route *route)
+{
+	if (sip_route_empty(route)) {
+		ast_verbose("sip_route_dump: no route/path\n");
+	} else {
+		struct sip_route_hop *hop;
+		sip_route_traverse(route, hop) {
+			ast_verbose("sip_route_dump: route/path hop: <%s>\n", hop->uri);
+		}
+	}
+}
+
+struct ast_str *sip_route_list(const struct sip_route *route, int formatcli, int skip)
+{
+	struct sip_route_hop *hop;
+	const char *comma;
+	struct ast_str *buf;
+	int i = 0 - skip;
+
+	buf = ast_str_create(64);
+	if (!buf) {
+		return NULL;
+	}
+
+	comma = formatcli ? ", " : ",";
+
+	sip_route_traverse(route, hop) {
+		if (i >= 0) {
+			ast_str_append(&buf, 0, "%s<%s>", i ? comma : "", hop->uri);
+		}
+		i++;
+	}
+
+	if (formatcli && i <= 0) {
+		ast_str_append(&buf, 0, "N/A");
+	}
+
+	return buf;
+}
+
+int sip_route_is_strict(struct sip_route *route)
+{
+	if (!route) {
+		return 0;
+	}
+
+	if (route->type == route_invalidated) {
+		struct sip_route_hop *hop = sip_route_first(route);
+		int ret = hop && (strstr(hop->uri, ";lr") == NULL);
+		route->type = ret ? route_strict : route_loose;
+		return ret;
+	}
+
+	return (route->type == route_strict) ? 1 : 0;
+}
+
+const char *sip_route_first_uri(const struct sip_route *route)
+{
+	struct sip_route_hop *hop = sip_route_first(route);
+	return hop ? hop->uri : NULL;
+}