]> git.ipfire.org Git - thirdparty/systemd.git/blobdiff - src/resolve/resolved-manager.c
resolved: make sure order of dns servers is stable
[thirdparty/systemd.git] / src / resolve / resolved-manager.c
index b4f4d07147f08ddb132c828efae71d447b47b87e..c3c61a0893c40511905ddcb83d509295be31cb93 100644 (file)
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  ***/
 
-#include <arpa/inet.h>
-#include <resolv.h>
-#include <linux/if.h>
-
-#include "resolved.h"
-#include "event-util.h"
-#include "network-util.h"
-#include "sd-dhcp-lease.h"
-#include "dhcp-lease-internal.h"
+#include <netinet/in.h>
+#include <poll.h>
+#include <sys/ioctl.h>
+
+#include "af-list.h"
+#include "alloc-util.h"
+#include "dns-domain.h"
+#include "fd-util.h"
+#include "fileio-label.h"
+#include "hostname-util.h"
+#include "io-util.h"
+#include "netlink-util.h"
 #include "network-internal.h"
-#include "conf-parser.h"
+#include "ordered-set.h"
+#include "parse-util.h"
+#include "random-util.h"
+#include "resolved-bus.h"
+#include "resolved-conf.h"
+#include "resolved-llmnr.h"
+#include "resolved-manager.h"
+#include "resolved-resolv-conf.h"
+#include "socket-util.h"
+#include "string-table.h"
+#include "string-util.h"
+#include "utf8.h"
+
+#define SEND_TIMEOUT_USEC (200 * USEC_PER_MSEC)
+
+static int manager_process_link(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) {
+        Manager *m = userdata;
+        uint16_t type;
+        Link *l;
+        int ifindex, r;
 
-static int set_fallback_dns(Manager *m, const char *string) {
-        char *word, *state;
-        size_t length;
-        int r;
+        assert(rtnl);
+        assert(m);
+        assert(mm);
+
+        r = sd_netlink_message_get_type(mm, &type);
+        if (r < 0)
+                goto fail;
+
+        r = sd_rtnl_message_link_get_ifindex(mm, &ifindex);
+        if (r < 0)
+                goto fail;
+
+        l = hashmap_get(m->links, INT_TO_PTR(ifindex));
+
+        switch (type) {
+
+        case RTM_NEWLINK:{
+                bool is_new = !l;
+
+                if (!l) {
+                        r = link_new(m, &l, ifindex);
+                        if (r < 0)
+                                goto fail;
+                }
 
+                r = link_update_rtnl(l, mm);
+                if (r < 0)
+                        goto fail;
+
+                r = link_update_monitor(l);
+                if (r < 0)
+                        goto fail;
+
+                if (is_new)
+                        log_debug("Found new link %i/%s", ifindex, l->name);
+
+                break;
+        }
+
+        case RTM_DELLINK:
+                if (l) {
+                        log_debug("Removing link %i/%s", l->ifindex, l->name);
+                        link_free(l);
+                }
+
+                break;
+        }
+
+        return 0;
+
+fail:
+        log_warning_errno(r, "Failed to process RTNL link message: %m");
+        return 0;
+}
+
+static int manager_process_address(sd_netlink *rtnl, sd_netlink_message *mm, void *userdata) {
+        Manager *m = userdata;
+        union in_addr_union address;
+        uint16_t type;
+        int r, ifindex, family;
+        LinkAddress *a;
+        Link *l;
+
+        assert(rtnl);
+        assert(mm);
         assert(m);
-        assert(string);
 
-        FOREACH_WORD_QUOTED(word, length, string, state) {
-                _cleanup_free_ Address *address = NULL;
-                Address *tail;
-                _cleanup_free_ char *addrstr = NULL;
+        r = sd_netlink_message_get_type(mm, &type);
+        if (r < 0)
+                goto fail;
+
+        r = sd_rtnl_message_addr_get_ifindex(mm, &ifindex);
+        if (r < 0)
+                goto fail;
+
+        l = hashmap_get(m->links, INT_TO_PTR(ifindex));
+        if (!l)
+                return 0;
 
-                address = new0(Address, 1);
-                if (!address)
-                        return -ENOMEM;
+        r = sd_rtnl_message_addr_get_family(mm, &family);
+        if (r < 0)
+                goto fail;
 
-                addrstr = strndup(word, length);
-                if (!addrstr)
-                        return -ENOMEM;
+        switch (family) {
 
-                r = net_parse_inaddr(addrstr, &address->family, &address->in_addr);
+        case AF_INET:
+                r = sd_netlink_message_read_in_addr(mm, IFA_LOCAL, &address.in);
                 if (r < 0) {
-                        log_debug("Ignoring invalid DNS address '%s'", addrstr);
-                        continue;
+                        r = sd_netlink_message_read_in_addr(mm, IFA_ADDRESS, &address.in);
+                        if (r < 0)
+                                goto fail;
                 }
 
-                LIST_FIND_TAIL(addresses, m->fallback_dns, tail);
-                LIST_INSERT_AFTER(addresses, m->fallback_dns, tail, address);
-                address = NULL;
+                break;
+
+        case AF_INET6:
+                r = sd_netlink_message_read_in6_addr(mm, IFA_LOCAL, &address.in6);
+                if (r < 0) {
+                        r = sd_netlink_message_read_in6_addr(mm, IFA_ADDRESS, &address.in6);
+                        if (r < 0)
+                                goto fail;
+                }
+
+                break;
+
+        default:
+                return 0;
+        }
+
+        a = link_find_address(l, family, &address);
+
+        switch (type) {
+
+        case RTM_NEWADDR:
+
+                if (!a) {
+                        r = link_address_new(l, &a, family, &address);
+                        if (r < 0)
+                                return r;
+                }
+
+                r = link_address_update_rtnl(a, mm);
+                if (r < 0)
+                        return r;
+
+                break;
+
+        case RTM_DELADDR:
+                link_address_free(a);
+                break;
         }
 
         return 0;
+
+fail:
+        log_warning_errno(r, "Failed to process RTNL address message: %m");
+        return 0;
 }
 
-int config_parse_dnsv(
-                const char *unit,
-                const char *filename,
-                unsigned line,
-                const char *section,
-                unsigned section_line,
-                const char *lvalue,
-                int ltype,
-                const char *rvalue,
-                void *data,
-                void *userdata) {
+static int manager_rtnl_listen(Manager *m) {
+        _cleanup_netlink_message_unref_ sd_netlink_message *req = NULL, *reply = NULL;
+        sd_netlink_message *i;
+        int r;
+
+        assert(m);
+
+        /* First, subscribe to interfaces coming and going */
+        r = sd_netlink_open(&m->rtnl);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_attach_event(m->rtnl, m->event, 0);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_add_match(m->rtnl, RTM_NEWLINK, manager_process_link, m);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_add_match(m->rtnl, RTM_DELLINK, manager_process_link, m);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_add_match(m->rtnl, RTM_NEWADDR, manager_process_address, m);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_add_match(m->rtnl, RTM_DELADDR, manager_process_address, m);
+        if (r < 0)
+                return r;
 
+        /* Then, enumerate all links */
+        r = sd_rtnl_message_new_link(m->rtnl, &req, RTM_GETLINK, 0);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_message_request_dump(req, true);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_call(m->rtnl, req, 0, &reply);
+        if (r < 0)
+                return r;
+
+        for (i = reply; i; i = sd_netlink_message_next(i)) {
+                r = manager_process_link(m->rtnl, i, m);
+                if (r < 0)
+                        return r;
+        }
+
+        req = sd_netlink_message_unref(req);
+        reply = sd_netlink_message_unref(reply);
+
+        /* Finally, enumerate all addresses, too */
+        r = sd_rtnl_message_new_addr(m->rtnl, &req, RTM_GETADDR, 0, AF_UNSPEC);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_message_request_dump(req, true);
+        if (r < 0)
+                return r;
+
+        r = sd_netlink_call(m->rtnl, req, 0, &reply);
+        if (r < 0)
+                return r;
+
+        for (i = reply; i; i = sd_netlink_message_next(i)) {
+                r = manager_process_address(m->rtnl, i, m);
+                if (r < 0)
+                        return r;
+        }
+
+        return r;
+}
+
+static int on_network_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
         Manager *m = userdata;
-        Address *address;
+        Iterator i;
+        Link *l;
+        int r;
 
-        assert(filename);
-        assert(lvalue);
-        assert(rvalue);
         assert(m);
 
-        while ((address = m->fallback_dns)) {
-                LIST_REMOVE(addresses, m->fallback_dns, address);
-                free(address);
+        sd_network_monitor_flush(m->network_monitor);
+
+        HASHMAP_FOREACH(l, m->links, i) {
+                r = link_update_monitor(l);
+                if (r < 0)
+                        log_warning_errno(r, "Failed to update monitor information for %i: %m", l->ifindex);
         }
 
-        set_fallback_dns(m, rvalue);
+        r = manager_write_resolv_conf(m);
+        if (r < 0)
+                log_warning_errno(r, "Could not update resolv.conf: %m");
 
         return 0;
 }
 
-static int manager_parse_config_file(Manager *m) {
+static int manager_network_monitor_listen(Manager *m) {
+        int r, fd, events;
+
+        assert(m);
+
+        r = sd_network_monitor_new(&m->network_monitor, NULL);
+        if (r < 0)
+                return r;
+
+        fd = sd_network_monitor_get_fd(m->network_monitor);
+        if (fd < 0)
+                return fd;
+
+        events = sd_network_monitor_get_events(m->network_monitor);
+        if (events < 0)
+                return events;
+
+        r = sd_event_add_io(m->event, &m->network_event_source, fd, events, &on_network_event, m);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+static int determine_hostname(char **llmnr_hostname, char **mdns_hostname) {
+        _cleanup_free_ char *h = NULL, *n = NULL;
+        char label[DNS_LABEL_MAX];
+        const char *p;
+        int r, k;
+
+        assert(llmnr_hostname);
+        assert(mdns_hostname);
+
+        /* Extract and normalize the first label of the locally
+         * configured hostname, and check it's not "localhost". */
+
+        h = gethostname_malloc();
+        if (!h)
+                return log_oom();
+
+        p = h;
+        r = dns_label_unescape(&p, label, sizeof(label));
+        if (r < 0)
+                return log_error_errno(r, "Failed to unescape host name: %m");
+        if (r == 0) {
+                log_error("Couldn't find a single label in hosntame.");
+                return -EINVAL;
+        }
+
+        k = dns_label_undo_idna(label, r, label, sizeof(label));
+        if (k < 0)
+                return log_error_errno(k, "Failed to undo IDNA: %m");
+        if (k > 0)
+                r = k;
+
+        if (!utf8_is_valid(label)) {
+                log_error("System hostname is not UTF-8 clean.");
+                return -EINVAL;
+        }
+
+        r = dns_label_escape(label, r, &n);
+        if (r < 0)
+                return log_error_errno(r, "Failed to escape host name: %m");
+
+        if (is_localhost(n)) {
+                log_debug("System hostname is 'localhost', ignoring.");
+                return -EINVAL;
+        }
+
+        r = dns_name_concat(n, "local", mdns_hostname);
+        if (r < 0)
+                return log_error_errno(r, "Failed to determine mDNS hostname: %m");
+
+        *llmnr_hostname = n;
+        n = NULL;
+
+        return 0;
+}
+
+static int on_hostname_change(sd_event_source *es, int fd, uint32_t revents, void *userdata) {
+        _cleanup_free_ char *llmnr_hostname = NULL, *mdns_hostname = NULL;
+        Manager *m = userdata;
         int r;
 
         assert(m);
 
-        r = config_parse(NULL, "/etc/systemd/resolved.conf", NULL,
-                         "Resolve\0", config_item_perf_lookup, (void*) resolved_gperf_lookup,
-                         false, false, m);
+        r = determine_hostname(&llmnr_hostname, &mdns_hostname);
         if (r < 0)
-                log_warning("Failed to parse configuration file: %s", strerror(-r));
+                return 0; /* ignore invalid hostnames */
 
-        return r;
+        if (streq(llmnr_hostname, m->llmnr_hostname) && streq(mdns_hostname, m->mdns_hostname))
+                return 0;
+
+        log_info("System hostname changed to '%s'.", llmnr_hostname);
+
+        free(m->llmnr_hostname);
+        free(m->mdns_hostname);
+
+        m->llmnr_hostname = llmnr_hostname;
+        m->mdns_hostname = mdns_hostname;
+
+        llmnr_hostname = mdns_hostname = NULL;
+
+        manager_refresh_rrs(m);
+
+        return 0;
+}
+
+static int manager_watch_hostname(Manager *m) {
+        int r;
+
+        assert(m);
+
+        m->hostname_fd = open("/proc/sys/kernel/hostname", O_RDONLY|O_CLOEXEC|O_NDELAY|O_NOCTTY);
+        if (m->hostname_fd < 0) {
+                log_warning_errno(errno, "Failed to watch hostname: %m");
+                return 0;
+        }
+
+        r = sd_event_add_io(m->event, &m->hostname_event_source, m->hostname_fd, 0, on_hostname_change, m);
+        if (r < 0) {
+                if (r == -EPERM)
+                        /* kernels prior to 3.2 don't support polling this file. Ignore the failure. */
+                        m->hostname_fd = safe_close(m->hostname_fd);
+                else
+                        return log_error_errno(r, "Failed to add hostname event source: %m");
+        }
+
+        r = determine_hostname(&m->llmnr_hostname, &m->mdns_hostname);
+        if (r < 0) {
+                log_info("Defaulting to hostname 'linux'.");
+                m->llmnr_hostname = strdup("linux");
+                if (!m->llmnr_hostname)
+                        return log_oom();
+
+                m->mdns_hostname = strdup("linux.local");
+                if (!m->mdns_hostname)
+                        return log_oom();
+        } else
+                log_info("Using system hostname '%s'.", m->llmnr_hostname);
+
+        return 0;
+}
+
+static int manager_sigusr1(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
+        _cleanup_free_ char *buffer = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        Manager *m = userdata;
+        size_t size = 0;
+        DnsScope *scope;
+
+        assert(s);
+        assert(si);
+        assert(m);
+
+        f = open_memstream(&buffer, &size);
+        if (!f)
+                return log_oom();
+
+        LIST_FOREACH(scopes, scope, m->dns_scopes)
+                dns_scope_dump(scope, f);
+
+        if (fflush_and_check(f) < 0)
+                return log_oom();
+
+        log_dump(LOG_INFO, buffer);
+        return 0;
 }
 
 int manager_new(Manager **ret) {
-        _cleanup_manager_free_ Manager *m = NULL;
+        _cleanup_(manager_freep) Manager *m = NULL;
         int r;
 
         assert(ret);
@@ -120,13 +470,13 @@ int manager_new(Manager **ret) {
         if (!m)
                 return -ENOMEM;
 
-        r = set_fallback_dns(m, DNS_SERVERS);
-        if (r < 0)
-                return r;
+        m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1;
+        m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1;
+        m->hostname_fd = -1;
 
-        r = manager_parse_config_file(m);
-        if (r < 0)
-                return r;
+        m->llmnr_support = SUPPORT_YES;
+        m->read_resolv_conf = true;
+        m->need_builtin_fallbacks = true;
 
         r = sd_event_default(&m->event);
         if (r < 0)
@@ -137,178 +487,576 @@ int manager_new(Manager **ret) {
 
         sd_event_set_watchdog(m->event, true);
 
+        r = manager_watch_hostname(m);
+        if (r < 0)
+                return r;
+
+        r = dns_scope_new(m, &m->unicast_scope, NULL, DNS_PROTOCOL_DNS, AF_UNSPEC);
+        if (r < 0)
+                return r;
+
+        r = manager_network_monitor_listen(m);
+        if (r < 0)
+                return r;
+
+        r = manager_rtnl_listen(m);
+        if (r < 0)
+                return r;
+
+        r = manager_connect_bus(m);
+        if (r < 0)
+                return r;
+
+        (void) sd_event_add_signal(m->event, &m->sigusr1_event_source, SIGUSR1, manager_sigusr1, m);
+
         *ret = m;
         m = NULL;
 
         return 0;
 }
 
-void manager_free(Manager *m) {
-        Address *address;
+int manager_start(Manager *m) {
+        int r;
+
+        assert(m);
+
+        r = manager_llmnr_start(m);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+Manager *manager_free(Manager *m) {
+        Link *l;
 
         if (!m)
-                return;
+                return NULL;
+
+        manager_flush_dns_servers(m, DNS_SERVER_SYSTEM);
+        manager_flush_dns_servers(m, DNS_SERVER_FALLBACK);
+
+        while ((l = hashmap_first(m->links)))
+               link_free(l);
+
+        while (m->dns_queries)
+                dns_query_free(m->dns_queries);
+
+        dns_scope_free(m->unicast_scope);
+
+        hashmap_free(m->links);
+        hashmap_free(m->dns_transactions);
 
         sd_event_source_unref(m->network_event_source);
         sd_network_monitor_unref(m->network_monitor);
-        sd_event_unref(m->event);
 
-        while ((address = m->fallback_dns)) {
-                LIST_REMOVE(addresses, m->fallback_dns, address);
-                free(address);
-        }
+        sd_netlink_unref(m->rtnl);
+        sd_event_source_unref(m->rtnl_event_source);
 
-        free(m);
-}
+        manager_llmnr_stop(m);
 
-static void append_dns(FILE *f, void *dns, unsigned char family, unsigned *count) {
-        char buf[INET6_ADDRSTRLEN];
-        const char *address;
+        sd_bus_slot_unref(m->prepare_for_sleep_slot);
+        sd_event_source_unref(m->bus_retry_event_source);
+        sd_bus_unref(m->bus);
 
-        assert(f);
-        assert(dns);
-        assert(count);
+        sd_event_source_unref(m->sigusr1_event_source);
 
-        address = inet_ntop(family, dns, buf, INET6_ADDRSTRLEN);
-        if (!address) {
-                log_warning("Invalid DNS address. Ignoring.");
-                return;
-        }
+        sd_event_unref(m->event);
+
+        dns_resource_key_unref(m->llmnr_host_ipv4_key);
+        dns_resource_key_unref(m->llmnr_host_ipv6_key);
 
-        if (*count == MAXNS)
-                fputs("# Too many DNS servers configured, the following entries "
-                      "may be ignored\n", f);
+        sd_event_source_unref(m->hostname_event_source);
+        safe_close(m->hostname_fd);
+        free(m->llmnr_hostname);
+        free(m->mdns_hostname);
 
-        fprintf(f, "nameserver %s\n", address);
+        free(m);
 
-        (*count) ++;
+        return NULL;
 }
 
-int manager_update_resolv_conf(Manager *m) {
-        const char *path = "/run/systemd/resolve/resolv.conf";
-        _cleanup_free_ char *temp_path = NULL;
-        _cleanup_fclose_ FILE *f = NULL;
-         _cleanup_free_ unsigned *indices = NULL;
-        Address *address;
-        unsigned count = 0;
-        int n, r, i;
+int manager_recv(Manager *m, int fd, DnsProtocol protocol, DnsPacket **ret) {
+        _cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;
+        union {
+                struct cmsghdr header; /* For alignment */
+                uint8_t buffer[CMSG_SPACE(MAXSIZE(struct in_pktinfo, struct in6_pktinfo))
+                               + CMSG_SPACE(int) /* ttl/hoplimit */
+                               + EXTRA_CMSG_SPACE /* kernel appears to require extra buffer space */];
+        } control;
+        union sockaddr_union sa;
+        struct msghdr mh = {};
+        struct cmsghdr *cmsg;
+        struct iovec iov;
+        int ms = 0, r;
+        ssize_t l;
 
         assert(m);
+        assert(fd >= 0);
+        assert(ret);
 
-        r = fopen_temporary(path, &f, &temp_path);
+        r = ioctl(fd, FIONREAD, &ms);
+        if (r < 0)
+                return -errno;
+        if (ms < 0)
+                return -EIO;
+
+        r = dns_packet_new(&p, protocol, ms);
         if (r < 0)
                 return r;
 
-        fchmod(fileno(f), 0644);
-
-        fputs("# This file is managed by systemd-resolved(8). Do not edit.\n#\n"
-              "# Third party programs must not access this file directly, but\n"
-              "# only through the symlink at /etc/resolv.conf. To manage\n"
-              "# resolv.conf(5) in a different way, replace the symlink by a\n"
-              "# static file or a different symlink.\n\n", f);
-
-        n = sd_network_get_ifindices(&indices);
-        if (n < 0)
-                n = 0;
-
-        for (i = 0; i < n; i++) {
-                _cleanup_dhcp_lease_unref_ sd_dhcp_lease *lease = NULL;
-                struct in_addr *nameservers;
-                struct in6_addr *nameservers6;
-                size_t nameservers_size;
-
-                r = sd_network_dhcp_use_dns(indices[i]);
-                if (r > 0) {
-                        r = sd_network_get_dhcp_lease(indices[i], &lease);
-                        if (r >= 0) {
-                                r = sd_dhcp_lease_get_dns(lease, &nameservers, &nameservers_size);
-                                if (r >= 0) {
-                                        unsigned j;
-
-                                        for (j = 0; j < nameservers_size; j++)
-                                                append_dns(f, &nameservers[j], AF_INET, &count);
-                                }
+        iov.iov_base = DNS_PACKET_DATA(p);
+        iov.iov_len = p->allocated;
+
+        mh.msg_name = &sa.sa;
+        mh.msg_namelen = sizeof(sa);
+        mh.msg_iov = &iov;
+        mh.msg_iovlen = 1;
+        mh.msg_control = &control;
+        mh.msg_controllen = sizeof(control);
+
+        l = recvmsg(fd, &mh, 0);
+        if (l < 0) {
+                if (errno == EAGAIN || errno == EINTR)
+                        return 0;
+
+                return -errno;
+        }
+
+        if (l <= 0)
+                return -EIO;
+
+        assert(!(mh.msg_flags & MSG_CTRUNC));
+        assert(!(mh.msg_flags & MSG_TRUNC));
+
+        p->size = (size_t) l;
+
+        p->family = sa.sa.sa_family;
+        p->ipproto = IPPROTO_UDP;
+        if (p->family == AF_INET) {
+                p->sender.in = sa.in.sin_addr;
+                p->sender_port = be16toh(sa.in.sin_port);
+        } else if (p->family == AF_INET6) {
+                p->sender.in6 = sa.in6.sin6_addr;
+                p->sender_port = be16toh(sa.in6.sin6_port);
+                p->ifindex = sa.in6.sin6_scope_id;
+        } else
+                return -EAFNOSUPPORT;
+
+        CMSG_FOREACH(cmsg, &mh) {
+
+                if (cmsg->cmsg_level == IPPROTO_IPV6) {
+                        assert(p->family == AF_INET6);
+
+                        switch (cmsg->cmsg_type) {
+
+                        case IPV6_PKTINFO: {
+                                struct in6_pktinfo *i = (struct in6_pktinfo*) CMSG_DATA(cmsg);
+
+                                if (p->ifindex <= 0)
+                                        p->ifindex = i->ipi6_ifindex;
+
+                                p->destination.in6 = i->ipi6_addr;
+                                break;
                         }
-                }
 
-                r = sd_network_get_dns(indices[i], &nameservers, &nameservers_size);
-                if (r >= 0) {
-                        unsigned j;
+                        case IPV6_HOPLIMIT:
+                                p->ttl = *(int *) CMSG_DATA(cmsg);
+                                break;
 
-                        for (j = 0; j < nameservers_size; j++)
-                                append_dns(f, &nameservers[j], AF_INET, &count);
+                        }
+                } else if (cmsg->cmsg_level == IPPROTO_IP) {
+                        assert(p->family == AF_INET);
 
-                        free(nameservers);
-                }
+                        switch (cmsg->cmsg_type) {
+
+                        case IP_PKTINFO: {
+                                struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg);
 
-                r = sd_network_get_dns6(indices[i], &nameservers6, &nameservers_size);
-                if (r >= 0) {
-                        unsigned j;
+                                if (p->ifindex <= 0)
+                                        p->ifindex = i->ipi_ifindex;
 
-                        for (j = 0; j < nameservers_size; j++)
-                                append_dns(f, &nameservers6[j], AF_INET6, &count);
+                                p->destination.in = i->ipi_addr;
+                                break;
+                        }
 
-                        free(nameservers6);
+                        case IP_TTL:
+                                p->ttl = *(int *) CMSG_DATA(cmsg);
+                                break;
+                        }
                 }
         }
 
-        LIST_FOREACH(addresses, address, m->fallback_dns)
-                append_dns(f, &address->in_addr, address->family, &count);
+        /* The Linux kernel sets the interface index to the loopback
+         * device if the packet came from the local host since it
+         * avoids the routing table in such a case. Let's unset the
+         * interface index in such a case. */
+        if (p->ifindex == LOOPBACK_IFINDEX)
+                p->ifindex = 0;
+
+        if (protocol != DNS_PROTOCOL_DNS) {
+                /* If we don't know the interface index still, we look for the
+                 * first local interface with a matching address. Yuck! */
+                if (p->ifindex <= 0)
+                        p->ifindex = manager_find_ifindex(m, p->family, &p->destination);
+        }
+
+        *ret = p;
+        p = NULL;
+
+        return 1;
+}
+
+static int sendmsg_loop(int fd, struct msghdr *mh, int flags) {
+        int r;
+
+        assert(fd >= 0);
+        assert(mh);
+
+        for (;;) {
+                if (sendmsg(fd, mh, flags) >= 0)
+                        return 0;
+
+                if (errno == EINTR)
+                        continue;
+
+                if (errno != EAGAIN)
+                        return -errno;
+
+                r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        return -ETIMEDOUT;
+        }
+}
+
+static int write_loop(int fd, void *message, size_t length) {
+        int r;
+
+        assert(fd >= 0);
+        assert(message);
+
+        for (;;) {
+                if (write(fd, message, length) >= 0)
+                        return 0;
 
-        fflush(f);
+                if (errno == EINTR)
+                        continue;
 
-        if (ferror(f) || rename(temp_path, path) < 0) {
-                r = -errno;
-                unlink(path);
-                unlink(temp_path);
+                if (errno != EAGAIN)
+                        return -errno;
+
+                r = fd_wait_for_event(fd, POLLOUT, SEND_TIMEOUT_USEC);
+                if (r < 0)
+                        return r;
+                if (r == 0)
+                        return -ETIMEDOUT;
+        }
+}
+
+int manager_write(Manager *m, int fd, DnsPacket *p) {
+        int r;
+
+        log_debug("Sending %s packet with id %u", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p));
+
+        r = write_loop(fd, DNS_PACKET_DATA(p), p->size);
+        if (r < 0)
                 return r;
+
+        return 0;
+}
+
+static int manager_ipv4_send(Manager *m, int fd, int ifindex, const struct in_addr *addr, uint16_t port, DnsPacket *p) {
+        union sockaddr_union sa = {
+                .in.sin_family = AF_INET,
+        };
+        union {
+                struct cmsghdr header; /* For alignment */
+                uint8_t buffer[CMSG_SPACE(sizeof(struct in_pktinfo))];
+        } control;
+        struct msghdr mh = {};
+        struct iovec iov;
+
+        assert(m);
+        assert(fd >= 0);
+        assert(addr);
+        assert(port > 0);
+        assert(p);
+
+        iov.iov_base = DNS_PACKET_DATA(p);
+        iov.iov_len = p->size;
+
+        sa.in.sin_addr = *addr;
+        sa.in.sin_port = htobe16(port),
+
+        mh.msg_iov = &iov;
+        mh.msg_iovlen = 1;
+        mh.msg_name = &sa.sa;
+        mh.msg_namelen = sizeof(sa.in);
+
+        if (ifindex > 0) {
+                struct cmsghdr *cmsg;
+                struct in_pktinfo *pi;
+
+                zero(control);
+
+                mh.msg_control = &control;
+                mh.msg_controllen = CMSG_LEN(sizeof(struct in_pktinfo));
+
+                cmsg = CMSG_FIRSTHDR(&mh);
+                cmsg->cmsg_len = mh.msg_controllen;
+                cmsg->cmsg_level = IPPROTO_IP;
+                cmsg->cmsg_type = IP_PKTINFO;
+
+                pi = (struct in_pktinfo*) CMSG_DATA(cmsg);
+                pi->ipi_ifindex = ifindex;
         }
 
+        return sendmsg_loop(fd, &mh, 0);
+}
+
+static int manager_ipv6_send(Manager *m, int fd, int ifindex, const struct in6_addr *addr, uint16_t port, DnsPacket *p) {
+        union sockaddr_union sa = {
+                .in6.sin6_family = AF_INET6,
+        };
+        union {
+                struct cmsghdr header; /* For alignment */
+                uint8_t buffer[CMSG_SPACE(sizeof(struct in6_pktinfo))];
+        } control;
+        struct msghdr mh = {};
+        struct iovec iov;
+
+        assert(m);
+        assert(fd >= 0);
+        assert(addr);
+        assert(port > 0);
+        assert(p);
+
+        iov.iov_base = DNS_PACKET_DATA(p);
+        iov.iov_len = p->size;
+
+        sa.in6.sin6_addr = *addr;
+        sa.in6.sin6_port = htobe16(port),
+        sa.in6.sin6_scope_id = ifindex;
+
+        mh.msg_iov = &iov;
+        mh.msg_iovlen = 1;
+        mh.msg_name = &sa.sa;
+        mh.msg_namelen = sizeof(sa.in6);
+
+        if (ifindex > 0) {
+                struct cmsghdr *cmsg;
+                struct in6_pktinfo *pi;
+
+                zero(control);
+
+                mh.msg_control = &control;
+                mh.msg_controllen = CMSG_LEN(sizeof(struct in6_pktinfo));
+
+                cmsg = CMSG_FIRSTHDR(&mh);
+                cmsg->cmsg_len = mh.msg_controllen;
+                cmsg->cmsg_level = IPPROTO_IPV6;
+                cmsg->cmsg_type = IPV6_PKTINFO;
+
+                pi = (struct in6_pktinfo*) CMSG_DATA(cmsg);
+                pi->ipi6_ifindex = ifindex;
+        }
+
+        return sendmsg_loop(fd, &mh, 0);
+}
+
+int manager_send(Manager *m, int fd, int ifindex, int family, const union in_addr_union *addr, uint16_t port, DnsPacket *p) {
+        assert(m);
+        assert(fd >= 0);
+        assert(addr);
+        assert(port > 0);
+        assert(p);
+
+        log_debug("Sending %s packet with id %u on interface %i/%s", DNS_PACKET_QR(p) ? "response" : "query", DNS_PACKET_ID(p), ifindex, af_to_name(family));
+
+        if (family == AF_INET)
+                return manager_ipv4_send(m, fd, ifindex, &addr->in, port, p);
+        else if (family == AF_INET6)
+                return manager_ipv6_send(m, fd, ifindex, &addr->in6, port, p);
+
+        return -EAFNOSUPPORT;
+}
+
+uint32_t manager_find_mtu(Manager *m) {
+        uint32_t mtu = 0;
+        Link *l;
+        Iterator i;
+
+        /* If we don't know on which link a DNS packet would be
+         * delivered, let's find the largest MTU that works on all
+         * interfaces we know of */
+
+        HASHMAP_FOREACH(l, m->links, i) {
+                if (l->mtu <= 0)
+                        continue;
+
+                if (mtu <= 0 || l->mtu < mtu)
+                        mtu = l->mtu;
+        }
+
+        return mtu;
+}
+
+int manager_find_ifindex(Manager *m, int family, const union in_addr_union *in_addr) {
+        LinkAddress *a;
+
+        assert(m);
+
+        a = manager_find_link_address(m, family, in_addr);
+        if (a)
+                return a->link->ifindex;
+
         return 0;
 }
 
-static int manager_network_event_handler(sd_event_source *s, int fd, uint32_t revents,
-                                         void *userdata) {
-        Manager *m = userdata;
+void manager_refresh_rrs(Manager *m) {
+        Iterator i;
+        Link *l;
+
+        assert(m);
+
+        m->llmnr_host_ipv4_key = dns_resource_key_unref(m->llmnr_host_ipv4_key);
+        m->llmnr_host_ipv6_key = dns_resource_key_unref(m->llmnr_host_ipv6_key);
+
+        HASHMAP_FOREACH(l, m->links, i) {
+                link_add_rrs(l, true);
+                link_add_rrs(l, false);
+        }
+}
+
+int manager_next_hostname(Manager *m) {
+        const char *p;
+        uint64_t u, a;
+        char *h, *k;
         int r;
 
         assert(m);
 
-        r = manager_update_resolv_conf(m);
-        if (r < 0)
-                log_warning("Could not update resolv.conf: %s", strerror(-r));
+        p = strchr(m->llmnr_hostname, 0);
+        assert(p);
 
-        sd_network_monitor_flush(m->network_monitor);
+        while (p > m->llmnr_hostname) {
+                if (!strchr("0123456789", p[-1]))
+                        break;
+
+                p--;
+        }
+
+        if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0)
+                u = 1;
+
+        /* Add a random number to the old value. This way we can avoid
+         * that two hosts pick the same hostname, win on IPv4 and lose
+         * on IPv6 (or vice versa), and pick the same hostname
+         * replacement hostname, ad infinitum. We still want the
+         * numbers to go up monotonically, hence we just add a random
+         * value 1..10 */
+
+        random_bytes(&a, sizeof(a));
+        u += 1 + a % 10;
+
+        if (asprintf(&h, "%.*s%" PRIu64, (int) (p - m->llmnr_hostname), m->llmnr_hostname, u) < 0)
+                return -ENOMEM;
+
+        r = dns_name_concat(h, "local", &k);
+        if (r < 0) {
+                free(h);
+                return r;
+        }
+
+        log_info("Hostname conflict, changing published hostname from '%s' to '%s'.", m->llmnr_hostname, h);
+
+        free(m->llmnr_hostname);
+        m->llmnr_hostname = h;
+
+        free(m->mdns_hostname);
+        m->mdns_hostname = k;
+
+        manager_refresh_rrs(m);
 
         return 0;
 }
 
-int manager_network_monitor_listen(Manager *m) {
-        _cleanup_event_source_unref_ sd_event_source *event_source = NULL;
-        _cleanup_network_monitor_unref_ sd_network_monitor *monitor = NULL;
-        int r, fd, events;
+LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) {
+        Iterator i;
+        Link *l;
 
-        r = sd_network_monitor_new(NULL, &monitor);
-        if (r < 0)
-                return r;
+        assert(m);
 
-        fd = sd_network_monitor_get_fd(monitor);
-        if (fd < 0)
-                return fd;
+        HASHMAP_FOREACH(l, m->links, i) {
+                LinkAddress *a;
 
-        events = sd_network_monitor_get_events(monitor);
-        if (events < 0)
-                return events;
+                a = link_find_address(l, family, in_addr);
+                if (a)
+                        return a;
+        }
 
-        r = sd_event_add_io(m->event, &event_source, fd, events,
-                            &manager_network_event_handler, m);
-        if (r < 0)
-                return r;
+        return NULL;
+}
+
+bool manager_our_packet(Manager *m, DnsPacket *p) {
+        assert(m);
+        assert(p);
+
+        return !!manager_find_link_address(m, p->family, &p->sender);
+}
+
+DnsScope* manager_find_scope(Manager *m, DnsPacket *p) {
+        Link *l;
+
+        assert(m);
+        assert(p);
 
-        m->network_monitor = monitor;
-        m->network_event_source = event_source;
-        monitor = NULL;
-        event_source = NULL;
+        l = hashmap_get(m->links, INT_TO_PTR(p->ifindex));
+        if (!l)
+                return NULL;
+
+        if (p->protocol == DNS_PROTOCOL_LLMNR) {
+                if (p->family == AF_INET)
+                        return l->llmnr_ipv4_scope;
+                else if (p->family == AF_INET6)
+                        return l->llmnr_ipv6_scope;
+        }
+
+        return NULL;
+}
+
+void manager_verify_all(Manager *m) {
+        DnsScope *s;
+
+        assert(m);
+
+        LIST_FOREACH(scopes, s, m->dns_scopes)
+                dns_zone_verify_all(&s->zone);
+}
+
+int manager_is_own_hostname(Manager *m, const char *name) {
+        int r;
+
+        assert(m);
+        assert(name);
+
+        if (m->llmnr_hostname) {
+                r = dns_name_equal(name, m->llmnr_hostname);
+                if (r != 0)
+                        return r;
+        }
+
+        if (m->mdns_hostname)
+                return dns_name_equal(name, m->mdns_hostname);
 
         return 0;
 }
+
+static const char* const support_table[_SUPPORT_MAX] = {
+        [SUPPORT_NO] = "no",
+        [SUPPORT_YES] = "yes",
+        [SUPPORT_RESOLVE] = "resolve",
+};
+DEFINE_STRING_TABLE_LOOKUP(support, Support);