diff options
Diffstat (limited to 'src/grp-resolve/systemd-resolved/resolved-manager.c')
-rw-r--r-- | src/grp-resolve/systemd-resolved/resolved-manager.c | 1379 |
1 files changed, 1379 insertions, 0 deletions
diff --git a/src/grp-resolve/systemd-resolved/resolved-manager.c b/src/grp-resolve/systemd-resolved/resolved-manager.c new file mode 100644 index 0000000000..e7ed54db1c --- /dev/null +++ b/src/grp-resolve/systemd-resolved/resolved-manager.c @@ -0,0 +1,1379 @@ +/*** + This file is part of systemd. + + Copyright 2014 Tom Gundersen <teg@jklm.no> + + 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 <netinet/in.h> +#include <poll.h> +#include <sys/ioctl.h> + +#include "sd-netlink/netlink-util.h" +#include "systemd-basic/af-list.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/dirent-util.h" +#include "systemd-basic/fd-util.h" +#include "systemd-basic/fileio-label.h" +#include "systemd-basic/hostname-util.h" +#include "systemd-basic/io-util.h" +#include "systemd-basic/ordered-set.h" +#include "systemd-basic/parse-util.h" +#include "systemd-basic/random-util.h" +#include "systemd-basic/socket-util.h" +#include "systemd-basic/string-table.h" +#include "systemd-basic/string-util.h" +#include "systemd-basic/utf8.h" +#include "systemd-network/network-internal.h" +#include "systemd-shared/dns-domain.h" + +#include "resolved-bus.h" +#include "resolved-conf.h" +#include "resolved-dns-stub.h" +#include "resolved-etc-hosts.h" +#include "resolved-llmnr.h" +#include "resolved-manager.h" +#include "resolved-mdns.h" +#include "resolved-resolv-conf.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; + + 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_process_rtnl(l, mm); + if (r < 0) + goto fail; + + r = link_update(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_remove_user(l); + 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); + + 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; + + r = sd_rtnl_message_addr_get_family(mm, &family); + if (r < 0) + goto fail; + + switch (family) { + + case AF_INET: + r = sd_netlink_message_read_in_addr(mm, IFA_LOCAL, &address.in); + if (r < 0) { + r = sd_netlink_message_read_in_addr(mm, IFA_ADDRESS, &address.in); + if (r < 0) + goto fail; + } + + 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; +} + +static int manager_rtnl_listen(Manager *m) { + _cleanup_(sd_netlink_message_unrefp) 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, SD_EVENT_PRIORITY_IMPORTANT); + 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; + Iterator i; + Link *l; + int r; + + assert(m); + + sd_network_monitor_flush(m->network_monitor); + + HASHMAP_FOREACH(l, m->links, i) { + r = link_update(l); + if (r < 0) + log_warning_errno(r, "Failed to update monitor information for %i: %m", l->ifindex); + } + + (void) manager_write_resolv_conf(m); + + return 0; +} + +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; + + r = sd_event_source_set_priority(m->network_event_source, SD_EVENT_PRIORITY_IMPORTANT+5); + if (r < 0) + return r; + + (void) sd_event_source_set_description(m->network_event_source, "network-monitor"); + + 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_new(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 = determine_hostname(&llmnr_hostname, &mdns_hostname); + if (r < 0) + return 0; /* ignore invalid hostnames */ + + 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"); + } + + (void) sd_event_source_set_description(m->hostname_event_source, "hostname"); + + r = determine_hostname(&m->llmnr_hostname, &m->mdns_hostname); + if (r < 0) { + log_info("Defaulting to hostname 'gnu-linux'."); + m->llmnr_hostname = strdup("gnu-linux"); + if (!m->llmnr_hostname) + return log_oom(); + + m->mdns_hostname = strdup("gnu-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; +} + +static int manager_sigusr2(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) { + Manager *m = userdata; + + assert(s); + assert(si); + assert(m); + + manager_flush_caches(m); + + return 0; +} + +int manager_new(Manager **ret) { + _cleanup_(manager_freep) Manager *m = NULL; + int r; + + assert(ret); + + m = new0(Manager, 1); + if (!m) + return -ENOMEM; + + m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1; + m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1; + m->mdns_ipv4_fd = m->mdns_ipv6_fd = -1; + m->dns_stub_udp_fd = m->dns_stub_tcp_fd = -1; + m->hostname_fd = -1; + + m->llmnr_support = RESOLVE_SUPPORT_YES; + m->mdns_support = RESOLVE_SUPPORT_NO; + m->dnssec_mode = DEFAULT_DNSSEC_MODE; + m->enable_cache = true; + m->read_resolv_conf = true; + m->need_builtin_fallbacks = true; + m->etc_hosts_last = m->etc_hosts_mtime = USEC_INFINITY; + + r = dns_trust_anchor_load(&m->trust_anchor); + if (r < 0) + return r; + + r = manager_parse_config_file(m); + if (r < 0) + return r; + + r = sd_event_default(&m->event); + if (r < 0) + return r; + + sd_event_add_signal(m->event, NULL, SIGTERM, NULL, NULL); + sd_event_add_signal(m->event, NULL, SIGINT, NULL, NULL); + + 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); + (void) sd_event_add_signal(m->event, &m->sigusr2_event_source, SIGUSR2, manager_sigusr2, m); + + manager_cleanup_saved_user(m); + + *ret = m; + m = NULL; + + return 0; +} + +int manager_start(Manager *m) { + int r; + + assert(m); + + r = manager_dns_stub_start(m); + if (r < 0) + return r; + + r = manager_llmnr_start(m); + if (r < 0) + return r; + + r = manager_mdns_start(m); + if (r < 0) + return r; + + return 0; +} + +Manager *manager_free(Manager *m) { + Link *l; + + if (!m) + return NULL; + + dns_server_unlink_all(m->dns_servers); + dns_server_unlink_all(m->fallback_dns_servers); + dns_search_domain_unlink_all(m->search_domains); + + 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); + + /* At this point only orphaned streams should remain. All others should have been freed already by their + * owners */ + while (m->dns_streams) + dns_stream_unref(m->dns_streams); + + 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_netlink_unref(m->rtnl); + sd_event_source_unref(m->rtnl_event_source); + + manager_llmnr_stop(m); + manager_mdns_stop(m); + manager_dns_stub_stop(m); + + sd_bus_slot_unref(m->prepare_for_sleep_slot); + sd_event_source_unref(m->bus_retry_event_source); + sd_bus_unref(m->bus); + + sd_event_source_unref(m->sigusr1_event_source); + sd_event_source_unref(m->sigusr2_event_source); + + sd_event_unref(m->event); + + dns_resource_key_unref(m->llmnr_host_ipv4_key); + dns_resource_key_unref(m->llmnr_host_ipv6_key); + + sd_event_source_unref(m->hostname_event_source); + safe_close(m->hostname_fd); + free(m->llmnr_hostname); + free(m->mdns_hostname); + + dns_trust_anchor_flush(&m->trust_anchor); + manager_etc_hosts_flush(m); + + free(m); + + return NULL; +} + +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; + ssize_t ms, l; + int r; + + assert(m); + assert(fd >= 0); + assert(ret); + + ms = next_datagram_size_fd(fd); + if (ms < 0) + return ms; + + r = dns_packet_new(&p, protocol, ms); + if (r < 0) + return r; + + 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) + return 0; + if (l < 0) { + if (errno == EAGAIN || errno == EINTR) + return 0; + + return -errno; + } + + 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; + } + + case IPV6_HOPLIMIT: + p->ttl = *(int *) CMSG_DATA(cmsg); + break; + + } + } else if (cmsg->cmsg_level == IPPROTO_IP) { + assert(p->family == AF_INET); + + switch (cmsg->cmsg_type) { + + case IP_PKTINFO: { + struct in_pktinfo *i = (struct in_pktinfo*) CMSG_DATA(cmsg); + + if (p->ifindex <= 0) + p->ifindex = i->ipi_ifindex; + + p->destination.in = i->ipi_addr; + break; + } + + case IP_TTL: + p->ttl = *(int *) CMSG_DATA(cmsg); + break; + } + } + } + + /* 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; + + 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; + } +} + +int manager_write(Manager *m, int fd, DnsPacket *p) { + int r; + + log_debug("Sending %s packet with id %" PRIu16 ".", 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 *destination, + uint16_t port, + const struct in_addr *source, + 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(destination); + assert(port > 0); + assert(p); + + iov.iov_base = DNS_PACKET_DATA(p); + iov.iov_len = p->size; + + sa.in.sin_addr = *destination; + 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; + + if (source) + pi->ipi_spec_dst = *source; + } + + return sendmsg_loop(fd, &mh, 0); +} + +static int manager_ipv6_send( + Manager *m, + int fd, + int ifindex, + const struct in6_addr *destination, + uint16_t port, + const struct in6_addr *source, + 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(destination); + assert(port > 0); + assert(p); + + iov.iov_base = DNS_PACKET_DATA(p); + iov.iov_len = p->size; + + sa.in6.sin6_addr = *destination; + 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; + + if (source) + pi->ipi6_addr = *source; + } + + return sendmsg_loop(fd, &mh, 0); +} + +int manager_send( + Manager *m, + int fd, + int ifindex, + int family, + const union in_addr_union *destination, + uint16_t port, + const union in_addr_union *source, + DnsPacket *p) { + + assert(m); + assert(fd >= 0); + assert(destination); + assert(port > 0); + assert(p); + + log_debug("Sending %s packet with id %" PRIu16 " 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, &destination->in, port, &source->in, p); + if (family == AF_INET6) + return manager_ipv6_send(m, fd, ifindex, &destination->in6, port, &source->in6, 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; +} + +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); + + p = strchr(m->llmnr_hostname, 0); + assert(p); + + 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; +} + +LinkAddress* manager_find_link_address(Manager *m, int family, const union in_addr_union *in_addr) { + Iterator i; + Link *l; + + assert(m); + + HASHMAP_FOREACH(l, m->links, i) { + LinkAddress *a; + + a = link_find_address(l, family, in_addr); + if (a) + return a; + } + + 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); + + l = hashmap_get(m->links, INT_TO_PTR(p->ifindex)); + if (!l) + return NULL; + + switch (p->protocol) { + case DNS_PROTOCOL_LLMNR: + if (p->family == AF_INET) + return l->llmnr_ipv4_scope; + else if (p->family == AF_INET6) + return l->llmnr_ipv6_scope; + + break; + + case DNS_PROTOCOL_MDNS: + if (p->family == AF_INET) + return l->mdns_ipv4_scope; + else if (p->family == AF_INET6) + return l->mdns_ipv6_scope; + + break; + + default: + break; + } + + 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; +} + +int manager_compile_dns_servers(Manager *m, OrderedSet **dns) { + DnsServer *s; + Iterator i; + Link *l; + int r; + + assert(m); + assert(dns); + + r = ordered_set_ensure_allocated(dns, &dns_server_hash_ops); + if (r < 0) + return r; + + /* First add the system-wide servers and domains */ + LIST_FOREACH(servers, s, m->dns_servers) { + r = ordered_set_put(*dns, s); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + + /* Then, add the per-link servers */ + HASHMAP_FOREACH(l, m->links, i) { + LIST_FOREACH(servers, s, l->dns_servers) { + r = ordered_set_put(*dns, s); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + } + + /* If we found nothing, add the fallback servers */ + if (ordered_set_isempty(*dns)) { + LIST_FOREACH(servers, s, m->fallback_dns_servers) { + r = ordered_set_put(*dns, s); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + } + + return 0; +} + +/* filter_route is a tri-state: + * < 0: no filtering + * = 0 or false: return only domains which should be used for searching + * > 0 or true: return only domains which are for routing only + */ +int manager_compile_search_domains(Manager *m, OrderedSet **domains, int filter_route) { + DnsSearchDomain *d; + Iterator i; + Link *l; + int r; + + assert(m); + assert(domains); + + r = ordered_set_ensure_allocated(domains, &dns_name_hash_ops); + if (r < 0) + return r; + + LIST_FOREACH(domains, d, m->search_domains) { + + if (filter_route >= 0 && + d->route_only != !!filter_route) + continue; + + r = ordered_set_put(*domains, d->name); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + + HASHMAP_FOREACH(l, m->links, i) { + + LIST_FOREACH(domains, d, l->search_domains) { + + if (filter_route >= 0 && + d->route_only != !!filter_route) + continue; + + r = ordered_set_put(*domains, d->name); + if (r == -EEXIST) + continue; + if (r < 0) + return r; + } + } + + return 0; +} + +DnssecMode manager_get_dnssec_mode(Manager *m) { + assert(m); + + if (m->dnssec_mode != _DNSSEC_MODE_INVALID) + return m->dnssec_mode; + + return DNSSEC_NO; +} + +bool manager_dnssec_supported(Manager *m) { + DnsServer *server; + Iterator i; + Link *l; + + assert(m); + + if (manager_get_dnssec_mode(m) == DNSSEC_NO) + return false; + + server = manager_get_dns_server(m); + if (server && !dns_server_dnssec_supported(server)) + return false; + + HASHMAP_FOREACH(l, m->links, i) + if (!link_dnssec_supported(l)) + return false; + + return true; +} + +void manager_dnssec_verdict(Manager *m, DnssecVerdict verdict, const DnsResourceKey *key) { + + assert(verdict >= 0); + assert(verdict < _DNSSEC_VERDICT_MAX); + + if (log_get_max_level() >= LOG_DEBUG) { + char s[DNS_RESOURCE_KEY_STRING_MAX]; + + log_debug("Found verdict for lookup %s: %s", + dns_resource_key_to_string(key, s, sizeof s), + dnssec_verdict_to_string(verdict)); + } + + m->n_dnssec_verdict[verdict]++; +} + +bool manager_routable(Manager *m, int family) { + Iterator i; + Link *l; + + assert(m); + + /* Returns true if the host has at least one interface with a routable address of the specified type */ + + HASHMAP_FOREACH(l, m->links, i) + if (link_relevant(l, family, false)) + return true; + + return false; +} + +void manager_flush_caches(Manager *m) { + DnsScope *scope; + + assert(m); + + LIST_FOREACH(scopes, scope, m->dns_scopes) + dns_cache_flush(&scope->cache); + + log_info("Flushed all caches."); +} + +void manager_cleanup_saved_user(Manager *m) { + _cleanup_closedir_ DIR *d = NULL; + struct dirent *de; + int r; + + assert(m); + + /* Clean up all saved per-link files in /run/systemd/resolve/netif/ that don't have a matching interface + * anymore. These files are created to persist settings pushed in by the user via the bus, so that resolved can + * be restarted without losing this data. */ + + d = opendir("/run/systemd/resolve/netif/"); + if (!d) { + if (errno == ENOENT) + return; + + log_warning_errno(errno, "Failed to open interface directory: %m"); + return; + } + + FOREACH_DIRENT_ALL(de, d, log_error_errno(errno, "Failed to read interface directory: %m")) { + _cleanup_free_ char *p = NULL; + int ifindex; + Link *l; + + if (!IN_SET(de->d_type, DT_UNKNOWN, DT_REG)) + continue; + + if (STR_IN_SET(de->d_name, ".", "..")) + continue; + + r = parse_ifindex(de->d_name, &ifindex); + if (r < 0) /* Probably some temporary file from a previous run. Delete it */ + goto rm; + + l = hashmap_get(m->links, INT_TO_PTR(ifindex)); + if (!l) /* link vanished */ + goto rm; + + if (l->is_managed) /* now managed by networkd, hence the bus settings are useless */ + goto rm; + + continue; + + rm: + p = strappend("/run/systemd/resolve/netif/", de->d_name); + if (!p) { + log_oom(); + return; + } + + (void) unlink(p); + } +} |