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/include/reqresp_parser.h

@@ -22,6 +22,30 @@
 #ifndef _SIP_REQRESP_H
 #define _SIP_REQRESP_H
 
+/*! \brief uri parameters */
+struct uriparams {
+	char *transport;
+	char *user;
+	char *method;
+	char *ttl;
+	char *maddr;
+	int lr;
+};
+
+struct contact {
+	AST_LIST_ENTRY(contact) list;
+	char *name;
+	char *user;
+	char *pass;
+	char *hostport;
+	struct uriparams params;
+	char *headers;
+	char *expires;
+	char *q;
+};
+
+AST_LIST_HEAD_NOLOCK(contactliststruct, contact);
+
 /*!
  * \brief parses a URI in its components.
  *

channels/sip/include/route.h

@@ -0,0 +1,120 @@
+/*
+ * 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 header file
+ */
+
+#ifndef _SIP_ROUTE_H
+#define _SIP_ROUTE_H
+
+#include "asterisk/linkedlists.h"
+#include "asterisk/strings.h"
+
+/*!
+ * \brief Opaque storage of a sip route hop
+ */
+struct sip_route_hop;
+
+/*!
+ * \internal \brief Internal enum to remember last calculated
+ */
+enum sip_route_type {
+	route_loose = 0,    /*!< The first hop contains ;lr or does not exist */
+	route_strict,       /*!< The first hop exists and does not contain ;lr */
+	route_invalidated,  /*!< strict/loose routing needs to be rechecked */
+};
+
+/*!
+ * \brief Structure to store route information
+ *
+ * \note This must be zero-filled on allocation
+ */
+struct sip_route {
+	AST_LIST_HEAD_NOLOCK(, sip_route_hop) list;
+	enum sip_route_type type;
+};
+
+/*!
+ * \brief Add a new hop to the route
+ *
+ * \param route Route
+ * \param uri Address of this hop
+ * \param len Length of hop not including null terminator
+ * \param inserthead If true then inserted the new route to the top of the list
+ *
+ * \retval Pointer to null terminated copy of URI on success
+ * \retval NULL on error
+ */
+const char *sip_route_add(struct sip_route *route, const char *uri, size_t len, int inserthead);
+
+/*!
+ * \brief Add routes from header
+ *
+ * \note This procedure is for headers that require use of <brackets>.
+ */
+void sip_route_process_header(struct sip_route *route, const char *header, int inserthead);
+
+/*!
+ * \brief copy route-set
+ *
+ * \retval non-zero on failure
+ * \retval 0 on success
+ */
+void sip_route_copy(struct sip_route *dst, const struct sip_route *src);
+
+/*!
+ * \brief Free all routes in the list
+ */
+void sip_route_clear(struct sip_route *route);
+
+/*!
+ * \brief Verbose dump of all hops for debugging
+ */
+void sip_route_dump(const struct sip_route *route);
+
+/*!
+ * \brief Make the comma separated list of route hops
+ *
+ * \param route Source of route list
+ * \param formatcli Add's space after comma's, print's N/A if list is empty.
+ * \param skip Number of hops to skip
+ *
+ * \retval an allocated struct ast_str on success
+ * \retval NULL on failure
+ */
+struct ast_str *sip_route_list(const struct sip_route *route, int formatcli, int skip)
+		__attribute_malloc__ __attribute_warn_unused_result__;
+
+/*!
+ * \brief Check if the route is strict
+ *
+ * \note The result is cached in route->type
+ */
+int sip_route_is_strict(struct sip_route *route);
+
+/*!
+ * \brief Get the URI of the route's first hop
+ */
+const char *sip_route_first_uri(const struct sip_route *route);
+
+/*!
+ * \brief Check if route has no URI's
+ */
+#define sip_route_empty(route) AST_LIST_EMPTY(&(route)->list)
+
+#endif

channels/sip/include/sip.h

@@ -39,6 +39,8 @@
 #include "asterisk/netsock2.h"
 #include "asterisk/features_config.h"
 
+#include "route.h"
+
 #ifndef FALSE
 #define FALSE    0
 #endif
@@ -847,12 +849,6 @@ struct sip_invite_param {
 	struct sip_proxy *outboundproxy; /*!< Outbound proxy URI */
 };
 
-/*! \brief Structure to save routing information for a SIP session */
-struct sip_route {
-	struct sip_route *next;
-	char hop[0];
-};
-
 /*! \brief Structure to store Via information */
 struct sip_via {
 	char *via;
@@ -1119,7 +1115,7 @@ struct sip_pvt {
 	struct ast_sockaddr ourip;           /*!< Our IP (as seen from the outside) */
 	enum transfermodes allowtransfer;   /*!< REFER: restriction scheme */
 	struct ast_channel *owner;          /*!< Who owns us (if we have an owner) */
-	struct sip_route *route;            /*!< Head of linked list of routing steps (fm Record-Route) */
+	struct sip_route route;             /*!< List of routing steps (fm Record-Route) */
 	struct sip_notify *notify;          /*!< Custom notify type */
 	struct sip_auth_container *peerauth;/*!< Realm authentication credentials */
 	int noncecount;                     /*!< Nonce-count */
@@ -1346,7 +1342,7 @@ struct sip_peer {
 	int timer_t1;                   /*!<  The maximum T1 value for the peer */
 	int timer_b;                    /*!<  The maximum timer B (transaction timeouts) */
 	int fromdomainport;             /*!<  The From: domain port */
-	struct sip_route *path;         /*!<  Head of linked list of out-of-dialog outgoing routing steps (fm Path headers) */
+	struct sip_route path;          /*!<  List of out-of-dialog outgoing routing steps (fm Path headers) */
 
 	/*XXX Seems like we suddenly have two flags with the same content. Why? To be continued... */
 	enum sip_peer_type type; /*!< Distinguish between "user" and "peer" types. This is used solely for CLI and manager commands */
@@ -1804,34 +1800,6 @@ struct sip_monitor_instance {
 	struct sip_epa_entry *suspension_entry;
 };
 
-/*!
- * \brief uri parameters
- *
- */
-
-struct uriparams {
-	char *transport;
-	char *user;
-	char *method;
-	char *ttl;
-	char *maddr;
-	int lr;
-};
-
-struct contact {
-	AST_LIST_ENTRY(contact) list;
-	char *name;
-	char *user;
-	char *pass;
-	char *hostport;
-	struct uriparams params;
-	char *headers;
-	char *expires;
-	char *q;
-};
-
-AST_LIST_HEAD_NOLOCK(contactliststruct, contact);
-
 /*! \brief List of well-known SIP options. If we get this in a require,
    we should check the list and answer accordingly. */
 static const struct cfsip_options {

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;
+}