#include <arpa/inet.h>

#include <resolv.h>

#include <net/if.h>

#include <sys/ioctl.h>

#include <sys/poll.h>

#include <netinet/in.h>

#include "rtnl-util.h"

#include "event-util.h"

#include "network-util.h"

#include "network-internal.h"

#include "conf-parser.h"

#include "socket-util.h"

#include "af-list.h"

#include "resolved.h"

#define SEND_TIMEOUT_USEC (200 * USEC_PER_MSEC)

static int manager_process_link(sd_rtnl *rtnl, sd_rtnl_message *mm, void *userdata) {

Manager *m = userdata;

uint16_t type;

Link *l;

int ifindex, r;

assert(rtnl);

assert(m);

assert(mm);

r = sd_rtnl_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;

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("Failed to process RTNL link message: %s", strerror(-r));

return 0;

}

static int manager_process_address(sd_rtnl *rtnl, sd_rtnl_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_rtnl_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_rtnl_message_read_in_addr(mm, IFA_LOCAL, &address.in);

if (r < 0) {

r = sd_rtnl_message_read_in_addr(mm, IFA_ADDRESS, &address.in);

if (r < 0)

goto fail;

}

break;

case AF_INET6:

r = sd_rtnl_message_read_in6_addr(mm, IFA_LOCAL, &address.in6);

if (r < 0) {

r = sd_rtnl_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:

if (a)

link_address_free(a);

break;

}

return 0;

fail:

log_warning("Failed to process RTNL address message: %s", strerror(-r));

return 0;

}

static int manager_rtnl_listen(Manager *m) {

_cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL, *reply = NULL;

sd_rtnl_message *i;

int r;

assert(m);

/* First, subscibe to interfaces coming and going */

r = sd_rtnl_open(&m->rtnl, 3, RTNLGRP_LINK, RTNLGRP_IPV4_IFADDR, RTNLGRP_IPV6_IFADDR);

if (r < 0)

return r;

r = sd_rtnl_attach_event(m->rtnl, m->event, 0);

if (r < 0)

return r;

r = sd_rtnl_add_match(m->rtnl, RTM_NEWLINK, manager_process_link, m);

if (r < 0)

return r;

r = sd_rtnl_add_match(m->rtnl, RTM_DELLINK, manager_process_link, m);

if (r < 0)

return r;

r = sd_rtnl_add_match(m->rtnl, RTM_NEWADDR, manager_process_address, m);

if (r < 0)

return r;

r = sd_rtnl_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_rtnl_message_request_dump(req, true);

if (r < 0)

return r;

r = sd_rtnl_call(m->rtnl, req, 0, &reply);

if (r < 0)

return r;

for (i = reply; i; i = sd_rtnl_message_next(i)) {

r = manager_process_link(m->rtnl, i, m);

if (r < 0)

return r;

}

req = sd_rtnl_message_unref(req);

reply = sd_rtnl_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_rtnl_message_request_dump(req, true);

if (r < 0)

return r;

r = sd_rtnl_call(m->rtnl, req, 0, &reply);

if (r < 0)

return r;

for (i = reply; i; i = sd_rtnl_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("Failed to update monitor information for %i: %s", l->ifindex, strerror(-r));

}

r = manager_write_resolv_conf(m);

if (r < 0)

log_warning("Could not update resolv.conf: %s", strerror(-r));

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 parse_dns_server_string(Manager *m, const char *string) {

const char *word, *state;

size_t length;

int r;

assert(m);

assert(string);

FOREACH_WORD_QUOTED(word, length, string, state) {

char buffer[length+1];

int family;

union in_addr_union addr;

memcpy(buffer, word, length);

buffer[length] = 0;

r = in_addr_from_string_auto(buffer, &family, &addr);

if (r < 0) {

log_warning("Ignoring invalid DNS address '%s'", buffer);

continue;

}

/* filter out duplicates */

if (manager_find_dns_server(m, family, &addr))

continue;

r = dns_server_new(m, NULL, NULL, family, &addr);

if (r < 0)

return r;

}

/* do not warn about state here, since probably systemd already did */

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) {

Manager *m = userdata;

int r;

assert(filename);

assert(lvalue);

assert(rvalue);

assert(m);

/* Empty assignment means clear the list */

if (isempty(rvalue)) {

while (m->dns_servers)

dns_server_free(m->dns_servers);

return 0;

}

r = parse_dns_server_string(m, rvalue);

if (r < 0) {

log_error("Failed to parse DNS server string");

return r;

}

return 0;

}

int manager_parse_config_file(Manager *m) {

assert(m);

return config_parse(NULL, "/etc/systemd/resolved.conf", NULL,

"Resolve\0",

config_item_perf_lookup, resolved_gperf_lookup,

false, false, true, m);

}

int manager_new(Manager **ret) {

_cleanup_(manager_freep) Manager *m = NULL;

int r;

assert(ret);

m = new0(Manager, 1);

if (!m)

return -ENOMEM;

m->dns_ipv4_fd = m->dns_ipv6_fd = -1;

m->llmnr_ipv4_udp_fd = m->llmnr_ipv6_udp_fd = -1;

m->llmnr_ipv4_tcp_fd = m->llmnr_ipv6_tcp_fd = -1;

m->use_llmnr = true;

r = parse_dns_server_string(m, DNS_SERVERS);

if (r < 0)

return r;

m->hostname = gethostname_malloc();

if (!m->hostname)

return -ENOMEM;

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 = 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;

r = manager_llmnr_ipv4_udp_fd(m);

if (r < 0)

return r;

r = manager_llmnr_ipv6_udp_fd(m);

if (r < 0)

return r;

r = manager_llmnr_ipv4_tcp_fd(m);

if (r < 0)

return r;

r = manager_llmnr_ipv6_tcp_fd(m);

if (r < 0)

return r;

*ret = m;

m = NULL;

return 0;

}

Manager *manager_free(Manager *m) {

Link *l;

if (!m)

return NULL;

while (m->dns_queries)

dns_query_free(m->dns_queries);

hashmap_free(m->dns_transactions);

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

link_free(l);

hashmap_free(m->links);

dns_scope_free(m->unicast_scope);

while (m->dns_servers)

dns_server_free(m->dns_servers);

sd_event_source_unref(m->network_event_source);

sd_network_monitor_unref(m->network_monitor);

sd_event_source_unref(m->dns_ipv4_event_source);

sd_event_source_unref(m->dns_ipv6_event_source);

safe_close(m->dns_ipv4_fd);

safe_close(m->dns_ipv6_fd);

sd_event_source_unref(m->llmnr_ipv4_udp_event_source);

sd_event_source_unref(m->llmnr_ipv6_udp_event_source);

safe_close(m->llmnr_ipv4_udp_fd);

safe_close(m->llmnr_ipv6_udp_fd);

sd_event_source_unref(m->llmnr_ipv4_tcp_event_source);

sd_event_source_unref(m->llmnr_ipv6_tcp_event_source);

safe_close(m->llmnr_ipv4_tcp_fd);

safe_close(m->llmnr_ipv6_tcp_fd);

sd_event_source_unref(m->bus_retry_event_source);

sd_bus_unref(m->bus);

sd_event_unref(m->event);

dns_resource_key_unref(m->host_ipv4_key);

dns_resource_key_unref(m->host_ipv6_key);

free(m->hostname);

free(m);

return NULL;

}

static void write_resolve_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("Invalid DNS address. Ignoring.");

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) ++;

}

int manager_write_resolv_conf(Manager *m) {

const char *path = "/run/systemd/resolve/resolv.conf";

_cleanup_free_ char *temp_path = NULL;

_cleanup_fclose_ FILE *f = NULL;

unsigned count = 0;

DnsServer *s;

Iterator i;

Link *l;

int r;

assert(m);

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

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);

HASHMAP_FOREACH(l, m->links, i)

LIST_FOREACH(servers, s, l->dns_servers)

write_resolve_conf_server(s, f, &count);

LIST_FOREACH(servers, s, m->dns_servers)

write_resolve_conf_server(s, f, &count);

r = fflush_and_check(f);

if (r < 0)

goto fail;

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

r = -errno;

goto fail;

}

return 0;

fail:

unlink(path);

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(MAX(sizeof(struct in_pktinfo), sizeof(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;

for (cmsg = CMSG_FIRSTHDR(&mh); cmsg; cmsg = CMSG_NXTHDR(&mh, cmsg)) {

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 > 0 && manager_ifindex_is_loopback(m, p->ifindex) != 0)

p->ifindex = 0;

/* 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 on_dns_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) {

_cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;

DnsTransaction *t = NULL;

Manager *m = userdata;

int r;

r = manager_recv(m, fd, DNS_PROTOCOL_DNS, &p);

if (r <= 0)

return r;

if (dns_packet_validate_reply(p) > 0) {

t = hashmap_get(m->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p)));

if (!t)

return 0;

dns_transaction_process_reply(t, p);

} else

log_debug("Invalid DNS packet.");

return 0;

}

int manager_dns_ipv4_fd(Manager *m) {

const int one = 1;

int r;

assert(m);

if (m->dns_ipv4_fd >= 0)

return m->dns_ipv4_fd;

m->dns_ipv4_fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);

if (m->dns_ipv4_fd < 0)

return -errno;

r = setsockopt(m->dns_ipv4_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = sd_event_add_io(m->event, &m->dns_ipv4_event_source, m->dns_ipv4_fd, EPOLLIN, on_dns_packet, m);

if (r < 0)

goto fail;

return m->dns_ipv4_fd;

fail:

m->dns_ipv4_fd = safe_close(m->dns_ipv4_fd);

return r;

}

int manager_dns_ipv6_fd(Manager *m) {

const int one = 1;

int r;

assert(m);

if (m->dns_ipv6_fd >= 0)

return m->dns_ipv6_fd;

m->dns_ipv6_fd = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);

if (m->dns_ipv6_fd < 0)

return -errno;

r = setsockopt(m->dns_ipv6_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = sd_event_add_io(m->event, &m->dns_ipv6_event_source, m->dns_ipv6_fd, EPOLLIN, on_dns_packet, m);

if (r < 0)

goto fail;

return m->dns_ipv6_fd;

fail:

m->dns_ipv6_fd = safe_close(m->dns_ipv6_fd);

return r;

}

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 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))

return s;

}

return NULL;

}

DnsServer *manager_get_dns_server(Manager *m) {

assert(m);

if (!m->current_dns_server)

m->current_dns_server = m->dns_servers;

return m->current_dns_server;

}

void manager_next_dns_server(Manager *m) {

assert(m);

if (!m->current_dns_server) {

m->current_dns_server = m->dns_servers;

return;

}

if (!m->current_dns_server)

return;

if (m->current_dns_server->servers_next) {

m->current_dns_server = m->current_dns_server->servers_next;

return;

}

m->current_dns_server = 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;

}

static int on_llmnr_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) {

_cleanup_(dns_packet_unrefp) DnsPacket *p = NULL;

DnsTransaction *t = NULL;

Manager *m = userdata;

int r;

r = manager_recv(m, fd, DNS_PROTOCOL_LLMNR, &p);

if (r <= 0)

return r;

if (dns_packet_validate_reply(p) > 0) {

log_debug("Got reply packet for id %u", DNS_PACKET_ID(p));

t = hashmap_get(m->dns_transactions, UINT_TO_PTR(DNS_PACKET_ID(p)));

if (!t)

return 0;

dns_transaction_process_reply(t, p);

} else if (dns_packet_validate_query(p) > 0) {

Link *l;

l = hashmap_get(m->links, INT_TO_PTR(p->ifindex));

if (l) {

DnsScope *scope = NULL;

if (p->family == AF_INET)

scope = l->llmnr_ipv4_scope;

else if (p->family == AF_INET6)

scope = l->llmnr_ipv6_scope;

if (scope)

dns_scope_process_query(scope, NULL, p);

}

} else

log_debug("Invalid LLMNR packet.");

return 0;

}

int manager_llmnr_ipv4_udp_fd(Manager *m) {

union sockaddr_union sa = {

.in.sin_family = AF_INET,

.in.sin_port = htobe16(5355),

};

static const int one = 1, pmtu = IP_PMTUDISC_DONT, ttl = 255;

int r;

assert(m);

if (m->llmnr_ipv4_udp_fd >= 0)

return m->llmnr_ipv4_udp_fd;

m->llmnr_ipv4_udp_fd = socket(AF_INET, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);

if (m->llmnr_ipv4_udp_fd < 0)

return -errno;

/* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */

r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_TTL, &ttl, sizeof(ttl));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_MULTICAST_LOOP, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv4_udp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

/* Disable Don't-Fragment bit in the IP header */

r = setsockopt(m->llmnr_ipv4_udp_fd, IPPROTO_IP, IP_MTU_DISCOVER, &pmtu, sizeof(pmtu));

if (r < 0) {

r = -errno;

goto fail;

}

r = bind(m->llmnr_ipv4_udp_fd, &sa.sa, sizeof(sa.in));

if (r < 0) {

r = -errno;

goto fail;

}

r = sd_event_add_io(m->event, &m->llmnr_ipv4_udp_event_source, m->llmnr_ipv4_udp_fd, EPOLLIN, on_llmnr_packet, m);

if (r < 0)

goto fail;

return m->llmnr_ipv4_udp_fd;

fail:

m->llmnr_ipv4_udp_fd = safe_close(m->llmnr_ipv4_udp_fd);

return r;

}

int manager_llmnr_ipv6_udp_fd(Manager *m) {

union sockaddr_union sa = {

.in6.sin6_family = AF_INET6,

.in6.sin6_port = htobe16(5355),

};

static const int one = 1, ttl = 255;

int r;

assert(m);

if (m->llmnr_ipv6_udp_fd >= 0)

return m->llmnr_ipv6_udp_fd;

m->llmnr_ipv6_udp_fd = socket(AF_INET6, SOCK_DGRAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);

if (m->llmnr_ipv6_udp_fd < 0)

return -errno;

r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &ttl, sizeof(ttl));

if (r < 0) {

r = -errno;

goto fail;

}

/* RFC 4795, section 2.5 recommends setting the TTL of UDP packets to 255. */

r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv6_udp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv6_udp_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = bind(m->llmnr_ipv6_udp_fd, &sa.sa, sizeof(sa.in6));

if (r < 0) {

r = -errno;

goto fail;

}

r = sd_event_add_io(m->event, &m->llmnr_ipv6_udp_event_source, m->llmnr_ipv6_udp_fd, EPOLLIN, on_llmnr_packet, m);

if (r < 0) {

r = -errno;

goto fail;

}

return m->llmnr_ipv6_udp_fd;

fail:

m->llmnr_ipv6_udp_fd = safe_close(m->llmnr_ipv6_udp_fd);

return r;

}

static int on_llmnr_stream_packet(DnsStream *s) {

assert(s);

if (dns_packet_validate_query(s->read_packet) > 0) {

Link *l;

l = hashmap_get(s->manager->links, INT_TO_PTR(s->read_packet->ifindex));

if (l) {

DnsScope *scope = NULL;

if (s->read_packet->family == AF_INET)

scope = l->llmnr_ipv4_scope;

else if (s->read_packet->family == AF_INET6)

scope = l->llmnr_ipv6_scope;

if (scope) {

dns_scope_process_query(scope, s, s->read_packet);

/* If no reply packet was set, we free the stream */

if (s->write_packet)

return 0;

}

}

}

dns_stream_free(s);

return 0;

}

static int on_llmnr_stream(sd_event_source *s, int fd, uint32_t revents, void *userdata) {

DnsStream *stream;

Manager *m = userdata;

int cfd, r;

cfd = accept4(fd, NULL, NULL, SOCK_NONBLOCK|SOCK_CLOEXEC);

if (cfd < 0) {

if (errno == EAGAIN || errno == EINTR)

return 0;

return -errno;

}

r = dns_stream_new(m, &stream, DNS_PROTOCOL_LLMNR, cfd);

if (r < 0) {

safe_close(cfd);

return r;

}

stream->on_packet = on_llmnr_stream_packet;

return 0;

}

int manager_llmnr_ipv4_tcp_fd(Manager *m) {

union sockaddr_union sa = {

.in.sin_family = AF_INET,

.in.sin_port = htobe16(5355),

};

static const int one = 1, pmtu = IP_PMTUDISC_DONT;

int r;

assert(m);

if (m->llmnr_ipv4_tcp_fd >= 0)

return m->llmnr_ipv4_tcp_fd;

m->llmnr_ipv4_tcp_fd = socket(AF_INET, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);

if (m->llmnr_ipv4_tcp_fd < 0)

return -errno;

/* RFC 4795, section 2.5. requires setting the TTL of TCP streams to 1 */

r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_TTL, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv4_tcp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_PKTINFO, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_RECVTTL, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

/* Disable Don't-Fragment bit in the IP header */

r = setsockopt(m->llmnr_ipv4_tcp_fd, IPPROTO_IP, IP_MTU_DISCOVER, &pmtu, sizeof(pmtu));

if (r < 0) {

r = -errno;

goto fail;

}

r = bind(m->llmnr_ipv4_tcp_fd, &sa.sa, sizeof(sa.in));

if (r < 0) {

r = -errno;

goto fail;

}

r = listen(m->llmnr_ipv4_tcp_fd, SOMAXCONN);

if (r < 0) {

r = -errno;

goto fail;

}

r = sd_event_add_io(m->event, &m->llmnr_ipv4_tcp_event_source, m->llmnr_ipv4_tcp_fd, EPOLLIN, on_llmnr_stream, m);

if (r < 0)

goto fail;

return m->llmnr_ipv4_tcp_fd;

fail:

m->llmnr_ipv4_tcp_fd = safe_close(m->llmnr_ipv4_tcp_fd);

return r;

}

int manager_llmnr_ipv6_tcp_fd(Manager *m) {

union sockaddr_union sa = {

.in6.sin6_family = AF_INET6,

.in6.sin6_port = htobe16(5355),

};

static const int one = 1;

int r;

assert(m);

if (m->llmnr_ipv6_tcp_fd >= 0)

return m->llmnr_ipv6_tcp_fd;

m->llmnr_ipv6_tcp_fd = socket(AF_INET6, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);

if (m->llmnr_ipv6_tcp_fd < 0)

return -errno;

/* RFC 4795, section 2.5. requires setting the TTL of TCP streams to 1 */

r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_UNICAST_HOPS, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv6_tcp_fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_RECVPKTINFO, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = setsockopt(m->llmnr_ipv6_tcp_fd, IPPROTO_IPV6, IPV6_RECVHOPLIMIT, &one, sizeof(one));

if (r < 0) {

r = -errno;

goto fail;

}

r = bind(m->llmnr_ipv6_tcp_fd, &sa.sa, sizeof(sa.in6));

if (r < 0) {

r = -errno;

goto fail;

}

r = listen(m->llmnr_ipv6_tcp_fd, SOMAXCONN);

if (r < 0) {

r = -errno;

goto fail;

}

r = sd_event_add_io(m->event, &m->llmnr_ipv6_tcp_event_source, m->llmnr_ipv6_tcp_fd, EPOLLIN, on_llmnr_stream, m);

if (r < 0) {

r = -errno;

goto fail;

}

return m->llmnr_ipv6_tcp_fd;

fail:

m->llmnr_ipv6_tcp_fd = safe_close(m->llmnr_ipv6_tcp_fd);

return r;

}

int manager_ifindex_is_loopback(Manager *m, int ifindex) {

Link *l;

assert(m);

if (ifindex <= 0)

return -EINVAL;

l = hashmap_get(m->links, INT_TO_PTR(ifindex));

if (l->flags & IFF_LOOPBACK)

return 1;

return 0;

}

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

LinkAddress *a;

assert(m);

a = manager_find_address(m, family, in_addr);

if (a)

return a->link->ifindex;

return 0;

}

int manager_next_hostname(Manager *m) {

const char *p;

Iterator i;

uint64_t u;

char *h;

Link *l;

assert(m);

p = strchr(m->hostname, 0);

assert(p);

while (p > m->hostname) {

if (!strchr("0123456789", p[-1]))

break;

p--;

}

if (*p == 0 || safe_atou64(p, &u) < 0 || u <= 0)

u = 1;

u++;

if (asprintf(&h, "%.*s%" PRIu64, (int) (p - m->hostname), m->hostname, u) < 0)

return -ENOMEM;

log_info("Hostname conflict, changing local hostname from '%s' to '%s'.", m->hostname, h);

free(m->hostname);

m->hostname = h;

m->host_ipv4_key = dns_resource_key_unref(m->host_ipv4_key);

m->host_ipv6_key = dns_resource_key_unref(m->host_ipv6_key);

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

link_add_rrs(l, true);

link_add_rrs(l, false);

}

return 0;

}

LinkAddress* manager_find_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;

}

int manager_our_packet(Manager *m, DnsPacket *p) {

assert(m);

assert(p);

return !!manager_find_address(m, p->family, &p->sender);

}