resolved: expose bus objects for each Link

The link objects expose as properties the current settings made with SetLinkDNS() and related calls, plus some more
information.

Makefile.am

@@ -5178,6 +5178,8 @@ systemd_resolved_SOURCES = \
 	src/resolve/resolved-bus.h \
 	src/resolve/resolved-link.h \
 	src/resolve/resolved-link.c \
+	src/resolve/resolved-link-bus.c \
+	src/resolve/resolved-link-bus.h \
 	src/resolve/resolved-llmnr.h \
 	src/resolve/resolved-llmnr.c \
 	src/resolve/resolved-mdns.h \

src/resolve/resolved-bus.c

@@ -25,6 +25,7 @@
 #include "dns-domain.h"
 #include "resolved-bus.h"
 #include "resolved-def.h"
+#include "resolved-link-bus.h"
 
 static int reply_query_state(DnsQuery *q) {
 
@@ -1116,17 +1117,23 @@ fail:
         return r;
 }
 
-static int append_dns_server(sd_bus_message *reply, DnsServer *s) {
+int bus_dns_server_append(sd_bus_message *reply, DnsServer *s, bool with_ifindex) {
         int r;
 
         assert(reply);
         assert(s);
 
-        r = sd_bus_message_open_container(reply, 'r', "iiay");
+        r = sd_bus_message_open_container(reply, 'r', with_ifindex ? "iiay" : "iay");
         if (r < 0)
                 return r;
 
-        r = sd_bus_message_append(reply, "ii", s->link ? s->link->ifindex : 0, s->family);
+        if (with_ifindex) {
+                r = sd_bus_message_append(reply, "i", s->link ? s->link->ifindex : 0);
+                if (r < 0)
+                        return r;
+        }
+
+        r = sd_bus_message_append(reply, "i", s->family);
         if (r < 0)
                 return r;
 
@@ -1161,7 +1168,7 @@ static int bus_property_get_dns_servers(
                 return r;
 
         LIST_FOREACH(servers, s, m->dns_servers) {
-                r = append_dns_server(reply, s);
+                r = bus_dns_server_append(reply, s, true);
                 if (r < 0)
                         return r;
 
@@ -1170,7 +1177,7 @@ static int bus_property_get_dns_servers(
 
         HASHMAP_FOREACH(l, m->links, i) {
                 LIST_FOREACH(servers, s, l->dns_servers) {
-                        r = append_dns_server(reply, s);
+                        r = bus_dns_server_append(reply, s, true);
                         if (r < 0)
                                 return r;
                         c++;
@@ -1179,7 +1186,7 @@ static int bus_property_get_dns_servers(
 
         if (c == 0) {
                 LIST_FOREACH(servers, s, m->fallback_dns_servers) {
-                        r = append_dns_server(reply, s);
+                        r = bus_dns_server_append(reply, s, true);
                         if (r < 0)
                                 return r;
                 }
@@ -1339,10 +1346,11 @@ static int bus_method_reset_statistics(sd_bus_message *message, void *userdata,
         return sd_bus_reply_method_return(message, NULL);
 }
 
-static int get_unmanaged_link(Manager *m, int ifindex, Link **ret, sd_bus_error *error) {
+static int get_any_link(Manager *m, int ifindex, Link **ret, sd_bus_error *error) {
         Link *l;
 
         assert(m);
+        assert(ret);
 
         if (ifindex <= 0)
                 return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid interface index");
@@ -1350,6 +1358,22 @@ static int get_unmanaged_link(Manager *m, int ifindex, Link **ret, sd_bus_error
         l = hashmap_get(m->links, INT_TO_PTR(ifindex));
         if (!l)
                 return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_LINK, "Link %i not known", ifindex);
+
+        *ret = l;
+        return 0;
+}
+
+static int get_unmanaged_link(Manager *m, int ifindex, Link **ret, sd_bus_error *error) {
+        Link *l;
+        int r;
+
+        assert(m);
+        assert(ret);
+
+        r = get_any_link(m, ifindex, &l, error);
+        if (r < 0)
+                return r;
+
         if (l->flags & IFF_LOOPBACK)
                 return sd_bus_error_setf(error, BUS_ERROR_LINK_BUSY, "Link %s is loopback device.", l->name);
         if (l->is_managed)
@@ -1686,6 +1710,32 @@ static int bus_method_revert_link(sd_bus_message *message, void *userdata, sd_bu
         return sd_bus_reply_method_return(message, NULL);
 }
 
+static int bus_method_get_link(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        _cleanup_free_ char *p = NULL;
+        Manager *m = userdata;
+        int r, ifindex;
+        Link *l;
+
+        assert(message);
+        assert(m);
+
+        assert_cc(sizeof(int) == sizeof(int32_t));
+
+        r = sd_bus_message_read(message, "i", &ifindex);
+        if (r < 0)
+                return r;
+
+        r = get_any_link(m, ifindex, &l, error);
+        if (r < 0)
+                return r;
+
+        p = link_bus_path(l);
+        if (!p)
+                return -ENOMEM;
+
+        return sd_bus_reply_method_return(message, "o", p);
+}
+
 static const sd_bus_vtable resolve_vtable[] = {
         SD_BUS_VTABLE_START(0),
         SD_BUS_PROPERTY("LLMNRHostname", "s", NULL, offsetof(Manager, llmnr_hostname), 0),
@@ -1701,6 +1751,7 @@ static const sd_bus_vtable resolve_vtable[] = {
         SD_BUS_METHOD("ResolveRecord", "isqqt", "a(iqqay)t", bus_method_resolve_record, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("ResolveService", "isssit", "a(qqqsa(iiay)s)aayssst", bus_method_resolve_service, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("ResetStatistics", NULL, NULL, bus_method_reset_statistics, 0),
+        SD_BUS_METHOD("GetLink", "i", "o", bus_method_get_link, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_METHOD("SetLinkDNS", "ia(iay)", NULL, bus_method_set_link_dns_servers, 0),
         SD_BUS_METHOD("SetLinkDomains", "ias", NULL, bus_method_set_link_domains, 0),
         SD_BUS_METHOD("SetLinkLLMNR", "is", NULL, bus_method_set_link_llmnr, 0),
@@ -1774,6 +1825,14 @@ int manager_connect_bus(Manager *m) {
         if (r < 0)
                 return log_error_errno(r, "Failed to register object: %m");
 
+        r = sd_bus_add_fallback_vtable(m->bus, NULL, "/org/freedesktop/resolve1/link", "org.freedesktop.resolve1.Link", link_vtable, link_object_find, m);
+        if (r < 0)
+                return log_error_errno(r, "Failed to register link objects: %m");
+
+        r = sd_bus_add_node_enumerator(m->bus, NULL, "/org/freedesktop/resolve1/link", link_node_enumerator, m);
+        if (r < 0)
+                return log_error_errno(r, "Failed to register link enumerator: %m");
+
         r = sd_bus_request_name(m->bus, "org.freedesktop.resolve1", 0);
         if (r < 0)
                 return log_error_errno(r, "Failed to register name: %m");

src/resolve/resolved-bus.h

@@ -24,3 +24,4 @@
 #include "resolved-manager.h"
 
 int manager_connect_bus(Manager *m);
+int bus_dns_server_append(sd_bus_message *reply, DnsServer *s, bool with_ifindex);

src/resolve/resolved-link-bus.c

@@ -0,0 +1,236 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2016 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "alloc-util.h"
+#include "bus-util.h"
+#include "parse-util.h"
+#include "resolve-util.h"
+#include "resolved-bus.h"
+#include "resolved-link-bus.h"
+#include "strv.h"
+
+static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_resolve_support, resolve_support, ResolveSupport);
+static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_dnssec_mode, dnssec_mode, DnssecMode);
+
+static int property_get_dns(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                const char *property,
+                sd_bus_message *reply,
+                void *userdata,
+                sd_bus_error *error) {
+
+        Link *l = userdata;
+        DnsServer *s;
+        int r;
+
+        assert(reply);
+        assert(l);
+
+        r = sd_bus_message_open_container(reply, 'a', "(iay)");
+        if (r < 0)
+                return r;
+
+        LIST_FOREACH(servers, s, l->dns_servers) {
+                r = bus_dns_server_append(reply, s, false);
+                if (r < 0)
+                        return r;
+        }
+
+        return sd_bus_message_close_container(reply);
+}
+
+static int property_get_domains(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                const char *property,
+                sd_bus_message *reply,
+                void *userdata,
+                sd_bus_error *error) {
+
+        Link *l = userdata;
+        DnsSearchDomain *d;
+        int r;
+
+        assert(reply);
+        assert(l);
+
+        r = sd_bus_message_open_container(reply, 'a', "s");
+        if (r < 0)
+                return r;
+
+        LIST_FOREACH(domains, d, l->search_domains) {
+                r = sd_bus_message_append(reply, "s", d->name);
+                if (r < 0)
+                        return r;
+        }
+
+        return sd_bus_message_close_container(reply);
+}
+
+static int property_get_scopes_mask(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                const char *property,
+                sd_bus_message *reply,
+                void *userdata,
+                sd_bus_error *error) {
+
+        Link *l = userdata;
+        uint64_t mask;
+
+        assert(reply);
+        assert(l);
+
+        mask =  (l->unicast_scope ? SD_RESOLVED_DNS : 0) |
+                (l->llmnr_ipv4_scope ? SD_RESOLVED_LLMNR_IPV4 : 0) |
+                (l->llmnr_ipv6_scope ? SD_RESOLVED_LLMNR_IPV6 : 0) |
+                (l->mdns_ipv4_scope ? SD_RESOLVED_MDNS_IPV4 : 0) |
+                (l->mdns_ipv6_scope ? SD_RESOLVED_MDNS_IPV6 : 0);
+
+        return sd_bus_message_append(reply, "t", mask);
+}
+
+static int property_get_ntas(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                const char *property,
+                sd_bus_message *reply,
+                void *userdata,
+                sd_bus_error *error) {
+
+        Link *l = userdata;
+        const char *name;
+        Iterator i;
+        int r;
+
+        assert(reply);
+        assert(l);
+
+        r = sd_bus_message_open_container(reply, 'a', "s");
+        if (r < 0)
+                return r;
+
+        SET_FOREACH(name, l->dnssec_negative_trust_anchors, i) {
+                r = sd_bus_message_append(reply, "s", name);
+                if (r < 0)
+                        return r;
+        }
+
+        return sd_bus_message_close_container(reply);
+}
+
+const sd_bus_vtable link_vtable[] = {
+        SD_BUS_VTABLE_START(0),
+
+        SD_BUS_PROPERTY("ScopesMask", "t", property_get_scopes_mask, 0, 0),
+        SD_BUS_PROPERTY("DNS", "a(iay)", property_get_dns, 0, 0),
+        SD_BUS_PROPERTY("Domains", "as", property_get_domains, 0, 0),
+        SD_BUS_PROPERTY("LLMNR", "s", property_get_resolve_support, offsetof(Link, llmnr_support), 0),
+        SD_BUS_PROPERTY("MulticastDNS", "s", property_get_resolve_support, offsetof(Link, mdns_support), 0),
+        SD_BUS_PROPERTY("DNSSEC", "s", property_get_dnssec_mode, offsetof(Link, dnssec_mode), 0),
+        SD_BUS_PROPERTY("DNSSECNegativeTrustAnchors", "as", property_get_ntas, 0, 0),
+
+        SD_BUS_VTABLE_END
+};
+
+int link_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) {
+        _cleanup_free_ char *e = NULL;
+        Manager *m = userdata;
+        int ifindex;
+        Link *link;
+        int r;
+
+        assert(bus);
+        assert(path);
+        assert(interface);
+        assert(found);
+        assert(m);
+
+        r = sd_bus_path_decode(path, "/org/freedesktop/resolve1/link", &e);
+        if (r <= 0)
+                return 0;
+
+        r = parse_ifindex(e, &ifindex);
+        if (r < 0)
+                return 0;
+
+        link = hashmap_get(m->links, INT_TO_PTR(ifindex));
+        if (!link)
+                return 0;
+
+        *found = link;
+        return 1;
+}
+
+char *link_bus_path(Link *link) {
+        _cleanup_free_ char *ifindex = NULL;
+        char *p;
+        int r;
+
+        assert(link);
+
+        if (asprintf(&ifindex, "%i", link->ifindex) < 0)
+                return NULL;
+
+        r = sd_bus_path_encode("/org/freedesktop/resolve1/link", ifindex, &p);
+        if (r < 0)
+                return NULL;
+
+        return p;
+}
+
+int link_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error) {
+        _cleanup_strv_free_ char **l = NULL;
+        Manager *m = userdata;
+        Link *link;
+        Iterator i;
+        unsigned c = 0;
+
+        assert(bus);
+        assert(path);
+        assert(m);
+        assert(nodes);
+
+        l = new0(char*, hashmap_size(m->links) + 1);
+        if (!l)
+                return -ENOMEM;
+
+        HASHMAP_FOREACH(link, m->links, i) {
+                char *p;
+
+                p = link_bus_path(link);
+                if (!p)
+                        return -ENOMEM;
+
+                l[c++] = p;
+        }
+
+        l[c] = NULL;
+        *nodes = l;
+        l = NULL;
+
+        return 1;
+}

src/resolve/resolved-link-bus.h

@@ -0,0 +1,32 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+#pragma once
+
+/***
+  This file is part of systemd.
+
+  Copyright 2016 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd is distributed in the hope that it will be useful, but
+  WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include "sd-bus.h"
+
+#include "resolved-link.h"
+
+extern const sd_bus_vtable link_vtable[];
+
+int link_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error);
+char *link_bus_path(Link *link);
+int link_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error);