#include <resolv.h>

#include <sys/ioctl.h>

#include <poll.h>

#include <netinet/in.h>

#include "netlink-util.h"

#include "network-internal.h"

#include "socket-util.h"

#include "af-list.h"

#include "utf8.h"

#include "fileio-label.h"

#include "ordered-set.h"

#include "random-util.h"

#include "hostname-util.h"

#include "dns-domain.h"

#include "resolved-conf.h"

#include "resolved-bus.h"

#include "resolved-manager.h"

#include "resolved-llmnr.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_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);

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_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;

Iterator i;

Link *l;

int r;

assert(m);

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);

}

r = manager_write_resolv_conf(m);

if (r < 0)

log_warning_errno(r, "Could not update 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;

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

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 = 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");

}

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_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->hostname_fd = -1;

m->llmnr_support = SUPPORT_YES;

m->read_resolv_conf = true;

r = manager_parse_dns_server(m, DNS_SERVER_FALLBACK, DNS_SERVERS);

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);

*ret = m;

m = NULL;

return 0;

}

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 NULL;

while ((l = hashmap_first(m->links)))

link_free(l);

while (m->dns_queries)

dns_query_free(m->dns_queries);

manager_flush_dns_servers(m, DNS_SERVER_SYSTEM);

manager_flush_dns_servers(m, DNS_SERVER_FALLBACK);

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);

manager_llmnr_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_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);

free(m);

return NULL;

}

int manager_read_resolv_conf(Manager *m) {

_cleanup_fclose_ FILE *f = NULL;

struct stat st, own;

char line[LINE_MAX];

DnsServer *s, *nx;

usec_t t;

int r;

assert(m);

/* Reads the system /etc/resolv.conf, if it exists and is not

if (!m->read_resolv_conf)

return 0;

r = stat("/etc/resolv.conf", &st);

if (r < 0) {

if (errno != ENOENT)

log_warning_errno(errno, "Failed to open /etc/resolv.conf: %m");

r = -errno;

goto clear;

}

/* Have we already seen the file? */

t = timespec_load(&st.st_mtim);

if (t == m->resolv_conf_mtime)

return 0;

m->resolv_conf_mtime = t;

/* Is it symlinked to our own file? */

if (stat("/run/systemd/resolve/resolv.conf", &own) >= 0 &&

st.st_dev == own.st_dev &&

st.st_ino == own.st_ino) {

r = 0;

goto clear;

}

f = fopen("/etc/resolv.conf", "re");

if (!f) {

if (errno != ENOENT)

log_warning_errno(errno, "Failed to open /etc/resolv.conf: %m");

r = -errno;

goto clear;

}

if (fstat(fileno(f), &st) < 0) {

r = log_error_errno(errno, "Failed to stat open file: %m");

goto clear;

}

LIST_FOREACH(servers, s, m->dns_servers)

s->marked = true;

FOREACH_LINE(line, f, r = -errno; goto clear) {

union in_addr_union address;

int family;

char *l;

const char *a;

truncate_nl(line);

l = strstrip(line);

if (*l == '#' || *l == ';')

continue;

a = first_word(l, "nameserver");

if (!a)

continue;

r = in_addr_from_string_auto(a, &family, &address);

if (r < 0) {

log_warning("Failed to parse name server %s.", a);

continue;

}

LIST_FOREACH(servers, s, m->dns_servers)

if (s->family == family && in_addr_equal(family, &s->address, &address) > 0)

break;

if (s)

s->marked = false;

else {

r = dns_server_new(m, NULL, DNS_SERVER_SYSTEM, NULL, family, &address);

if (r < 0)

goto clear;

}

}

LIST_FOREACH_SAFE(servers, s, nx, m->dns_servers)

if (s->marked) {

LIST_REMOVE(servers, m->dns_servers, s);

dns_server_unref(s);

}

/* Whenever /etc/resolv.conf changes, start using the first

manager_set_dns_server(m, m->dns_servers);

return 0;

clear:

while (m->dns_servers) {

s = m->dns_servers;

LIST_REMOVE(servers, m->dns_servers, s);

dns_server_unref(s);

}

return r;

}

static void write_resolv_conf_server(DnsServer *s, FILE *f, unsigned *count) {

_cleanup_free_ char *t = NULL;

int r;

assert(s);

assert(f);

assert(count);

r = in_addr_to_string(s->family, &s->address, &t);

if (r < 0) {

log_warning_errno(r, "Invalid DNS address. Ignoring: %m");

return;

}

if (*count == MAXNS)

fputs("# Too many DNS servers configured, the following entries may be ignored.\n", f);

fprintf(f, "nameserver %s\n", t);

(*count) ++;

}

static void write_resolv_conf_search(

const char *domain, FILE *f,

unsigned *count,

unsigned *length) {

assert(domain);

assert(f);

assert(length);

if (*count >= MAXDNSRCH ||

*length + strlen(domain) > 256) {

if (*count == MAXDNSRCH)

fputs(" # Too many search domains configured, remaining ones ignored.", f);

if (*length <= 256)

fputs(" # Total length of all search domains is too long, remaining ones ignored.", f);

return;

}

fprintf(f, " %s", domain);

(*length) += strlen(domain);

(*count) ++;

}

static int write_resolv_conf_contents(FILE *f, OrderedSet *dns, OrderedSet *domains) {

Iterator i;

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);

if (ordered_set_isempty(dns))

fputs("# No DNS servers known.\n", f);

else {

DnsServer *s;

unsigned count = 0;

ORDERED_SET_FOREACH(s, dns, i)

write_resolv_conf_server(s, f, &count);

}

if (!ordered_set_isempty(domains)) {

unsigned length = 0, count = 0;

char *domain;

fputs("search", f);

ORDERED_SET_FOREACH(domain, domains, i)

write_resolv_conf_search(domain, f, &count, &length);

fputs("\n", f);

}

return fflush_and_check(f);

}

int manager_write_resolv_conf(Manager *m) {

static const char path[] = "/run/systemd/resolve/resolv.conf";

_cleanup_free_ char *temp_path = NULL;

_cleanup_fclose_ FILE *f = NULL;

_cleanup_ordered_set_free_ OrderedSet *dns = NULL, *domains = NULL;

DnsServer *s;

Iterator i;

Link *l;

int r;

assert(m);

/* Read the system /etc/resolv.conf first */

manager_read_resolv_conf(m);

/* Add the full list to a set, to filter out duplicates */

dns = ordered_set_new(&dns_server_hash_ops);

if (!dns)

return -ENOMEM;

domains = ordered_set_new(&dns_name_hash_ops);

if (!domains)

return -ENOMEM;

/* First add the system-wide servers */

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 and domains */

HASHMAP_FOREACH(l, m->links, i) {

char **domain;

LIST_FOREACH(servers, s, l->dns_servers) {

r = ordered_set_put(dns, s);

if (r == -EEXIST)

continue;

if (r < 0)

return r;

}

if (!l->unicast_scope)

continue;

STRV_FOREACH(domain, l->unicast_scope->domains) {

r = ordered_set_put(domains, *domain);

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;

}

}

r = fopen_temporary_label(path, path, &f, &temp_path);

if (r < 0)

return r;

fchmod(fileno(f), 0644);

r = write_resolv_conf_contents(f, dns, domains);

if (r < 0)

goto fail;

if (rename(temp_path, path) < 0) {

r = -errno;

goto fail;

}

return 0;

fail:

(void) unlink(path);

(void) unlink(temp_path);

return r;

}

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 = 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;

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;

}

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

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

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 %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;

}

DnsServer* manager_find_dns_server(Manager *m, int family, const union in_addr_union *in_addr) {

DnsServer *s;

assert(m);

assert(in_addr);

LIST_FOREACH(servers, s, m->dns_servers)

if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0)

return s;

LIST_FOREACH(servers, s, m->fallback_dns_servers)

if (s->family == family && in_addr_equal(family, &s->address, in_addr) > 0)

return s;

return NULL;

}

DnsServer *manager_set_dns_server(Manager *m, DnsServer *s) {

assert(m);

if (m->current_dns_server == s)

return s;

if (s) {

_cleanup_free_ char *ip = NULL;

in_addr_to_string(s->family, &s->address, &ip);

log_info("Switching to system DNS server %s.", strna(ip));

}

m->current_dns_server = s;

if (m->unicast_scope)

dns_cache_flush(&m->unicast_scope->cache);

return s;

}

DnsServer *manager_get_dns_server(Manager *m) {

Link *l;

assert(m);

/* Try to read updates resolv.conf */

manager_read_resolv_conf(m);

if (!m->current_dns_server)

manager_set_dns_server(m, m->dns_servers);

if (!m->current_dns_server) {

bool found = false;

Iterator i;

/* No DNS servers configured, let's see if there are

HASHMAP_FOREACH(l, m->links, i)

if (l->dns_servers) {

found = true;

break;

}

if (!found)

manager_set_dns_server(m, m->fallback_dns_servers);

}

return m->current_dns_server;

}

void manager_next_dns_server(Manager *m) {

assert(m);

/* If there's currently no DNS server set, then the next

if (!m->current_dns_server)

return;

/* Change to the next one */

if (m->current_dns_server->servers_next) {

manager_set_dns_server(m, m->current_dns_server->servers_next);

return;

}

/* If there was no next one, then start from the beginning of

if (m->current_dns_server->type == DNS_SERVER_FALLBACK)

manager_set_dns_server(m, m->fallback_dns_servers);

else

manager_set_dns_server(m, m->dns_servers);

}

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

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

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;

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);

}

void manager_flush_dns_servers(Manager *m, DnsServerType t) {

DnsServer *s;

assert(m);

if (t == DNS_SERVER_SYSTEM)

while (m->dns_servers) {

s = m->dns_servers;

LIST_REMOVE(servers, m->dns_servers, s);

dns_server_unref(s);

}

if (t == DNS_SERVER_FALLBACK)

while (m->fallback_dns_servers) {

s = m->fallback_dns_servers;

LIST_REMOVE(servers, m->fallback_dns_servers, s);

dns_server_unref(s);

}

}

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);